* GB785153 (A)

Description: GB785153 (A) ? 1957-10-23

Improvements in or relating to separation of acid gases from coalcarbonisation gases

Description of GB785153 (A)

PATENT SPECIFICATION 785,153 -Date of Application and filing Complete Specification: Oct II -1955 No 28951155. Application made in United States of America on Nov 22, 1954. Complete Specification Published: Oct 23, 1957. Index at Acceptance;-Classes 1 ( 2), Ai D, Bl G, F 1 Z 12; and 55 ( 2),-D 1 m 7 B. International Classification:-C Olc Cl Ob. COMPLETE SPECIFICATION Improvements in or relating to Separation of Acid Gases from Coal Carbonisation Gases We, KOPPERS COMPANY INC, a corporation vapour is separated from the acidic gases, organised under the laws of the State of three problems are encountered: first, the Delaware, one of the United States of America, O vacuum pump plugs up apparently due to of 436, Seventh Avenue, City of Pittsburgh, polymer formation; second, small amounts of State of Pennsylvania, United States of ammonia contaminate the separated gases; 50 America, do hereby declare the invention, for and third, high melting point hydro-carbons, which we pray that a Patent may be granted to such as naphthalene and phenanthrene clog us, and the method by which it is to be per up condenser lines Although the concentration formed, to be particularly described in and by of the ammonia and high melting point hydrothe following statement: carbons in the vapours leaving the actifier may 55 This invention relates to the separation of be low, when the volume is reduced so greatly acid gases, such as hydrogen sulfide, hydrogen by the removal of water the concentration of cyanide and carbon dioxide from gases con these contaminants rapidly builds up in the taining them, for example, coal-carbonisation residual acidic gases The high melting-pointgases compounds precipitate in the tubes and parts 60 One

well known method for separation of of the condensers and ammonia-promoted acidic vapours from gases, particularly those polymer compounds act to clog piping and that may still also contain small amounts of vapour passages that convey acid gases to the ammonia is the hot-vacuuni-actification pro vacuum pump It is important, therefore, that cess The hot-vacuum-actification process of these contaminants be removed in order to 65 separating acid gases from, for example, coke permit an efficient separation of the water oven gases, comprises broadly absorbing the vapour from the acidic gases. acid gases such as H 2 S, HCN and CO 2 in an A disadvantage of the vacuum carbonate alkali-metal carbonate solution in a scrubber, process, therefore, was that equipment used in then heating the alkaline solution under a refining the acidic gases was frequently ren 70 high vacuum in an actifier to drive the acid dered inoperative by contaminating compounds gases out of the absorption solution At the such as naphthalene and phenanthrene which same time the absorption solution is regenerated clogged condenser tubes, valves and orifices. so that the solution may be returned to the In addition, ammonia, that was fortuitously scrubber in a closed cycle This hot-vacuum either continuously or periodically present in 75 actification process is described in detail in the actifier vapours, caused polymerization of prior Patent No 190115 constituents of the vapours to -give reaction An alkaline metal carbonate solution gener products that deposited in the condensers and ally is employed to absorb the acid gases from thus led to obstruction of their vapour passagethe gas, and when the fouled solution is heated ways The problem of clogged condenser tubes, 80 under a vacuum to remove the acid gases a valves and other orifices was solved by Gollmer very large volume of water vapour is formed so and is the subject of prior Patent No 675348. that it is necessary to separate the water vapour By the process described in the aforesaid from the acid gas before the acid gases can be prior Patent No 675348 ingredients which further separated and refined Since an caused clogging of condenser tubes, valves and 85 alkaline metal carbonate solution normally is other orifices were removed from the vapours employed to absorb the acid gases from the by the use of a comparatively small amount of fuel gas,-the process has become known as the solvents, resulting in operation without clogging "vacuum carbonate process" of passageways of condensers and the like and In that part of the process wherein water some improvement in vacuum pump operation 90 lPrice 3 s 6 d 1 r 4-ti,&l because of removal of ammonia before the gas passed through the vacuum pump However, while lines were clear from clogging by high melting point hydro-carbons, the problem of Vacuum pump stoppage was not completely solved In commercial installations 'whereil the vacuum carbonate

process is employed it has still been necessary to shut down periodically to clean out the pump By the practice of this invention shut-downs for this purpose are substantially eliminated. This invention is based on the discovery that polymerization occurs: in-:-the pump itself by virtue of heat generated when the acid gases, at the high vacuum that is necessary to release them from the absorption solution in the actifier, are compressed to pressure required to propel them to the point of utilization. Hydrogen sulfide, and hydrogen cyanide passing through the pump, possibly with other contaminants, form hard polymers at temperatures -resulting from a high pump compression ratio -In accordance with this invention:when H 1 N is desired high compressior F ratios are reduced -and, while there is some formation-of liquid polymer, formation of hard polymers is substantiallyeliminated In-another aspect of -the invention, particularly where HCN recovery is niot desired pumps are eliminfated; Before the process of -prior Patent No. 675348 'it was not practical to keep the hotvacuun T-actlflcation plant operating at capacity because naphthalene would plug condensing equipment in less than one day's time After employing the process of prior Patent No. 675348 hot-vacuum-actifier plant could be operated at capacity in spite of naphthalene,phenanthrene and the like However, the plant could not be' operated continuously for periods longer than, one or two months -because of shutdo Wns that were necessary to remove polymer obstructions in and after the vacuum pump. Reducing the pump compression ratio in ac-cordance -withy this invention has resulted in improved physical conditions and continuous operation for ten months, and there is no indication that the plant will have to be shutdown for polymer removal in the-future The various features of the invention are -shown in the accompanying drawing which is illustrative only, and not limiting, inasfar as the invention is concerned The drawing is a -diagrammatic flow sheet of t he hiot-vacuum-actifter process and the apparatus employed inrefiningthe actifiedvapours to -separate them from water and contaminants. Referring now-to the drawing; coke oven gas -which' contains hydrogen sulfide, hydrogen cyanide, carbon' dioxide, ammonia, phenanthrene, naphthalene-and other constituents, is introduced into a scrubber 4-through an inlet pipe 2 and passes upwardly through the scrubber in counter-current circulation with an alkaline absorbing solution introduced into the top of the scrubber through a distributor 5. Preferably a mixture of sodium carbonate and sodium bicarbonate is used for absorbing the acid gases from the coke oven gas The scrubbed coke oven gas leaves the top of the 70 scrubber through an outlet 6 Fouled alkaline absorption liquid is drawn off from the bottom of the

scrubber 4 by a pump 7 and is forced through a line 10 into a distributor 11 located in the top of an actifying tower 12 75 In the actifying tower the fouled liquor is heated under a high vacuum of approximately 4 inches of mercury absolute pressure to drive off the constituents absorbed in the alkaline liquor in the scrubber The alkaline liquor 80 flows downwardly through the actifier 12 and is met with water vapours generated from the alkaline solution by heating coil 16 A very large amount of' water is vaporised in the actifier and this water vapour flows upwardly 85 through the actifier counter-current to the alkaline solution to assist in releasing and stripping constituents absorbed by the alkaline solution in the scrubber Revivified alkaline -solution accumulates in the bottom of the 90 actifier and is drawn off through a line -13 to a pump 14 and is then returned through a line into the distributor 5 in the scrubber 4. Therefore the alkaline absorption solution is circulated in a closed cycle between the 95 scrubber and the actifier in which the absorption solution is-revivified Since a large amount of water is removed in revivifying the alkaline solution, water is added to the revivified -alkaline solution leaving the bottom of the 100 actifier through a line 58, the water supplied through' the line -58 being water that is condensed and separated from the actifier vapours in the latter part of the refining operation, as will be hereinafter described 105 The coke oven gas is delivered to the scrubber 4 in a heated condition which varies from 450 to 60 WC With the high partial vacuum in the actifier 12 ( 4 inches of mercury absolute) a temperature of approximately 550 C 110 exists in the actifier Before the acidic gases are separated from the other actifier vapours all the actifier vapours are cooled to condense and separate the water therefrom Accordingly the gases 'and vapours -are passed through 115 cooling condensers which are maintained under -substantially the same pressure that exists in the actifier The pressure in the actifier 12 may be varied between 3 to 9 inches of mercury absolute and the boiling temperature of the 120 solution therein will vary accordingly. Vapours leave the actifier through a vapour line 20 and eater a condenser 21 to be contracted in volume to separate liquid water. In order to prevent the clogging of the con 125 denser 21 due -to precipitation of compounds such as naphthalene and phenanthrene in the form of solids, a solvent oil in the vapour form is introduced into the vapour line 20 in a manner to thoroughly mix the oil vapours with the 130 785,153 aciified-vapours containing-the water vapoi An oil which has been found to be suit -for dissolving the -high melting point-hy carbons is a petroleum distillate which 1 within the-temperature range of 1000 to 30 ' with the major portion boiling

between and 2800 C When the vapours of such ai are mixed with the actifier vapours contai naphthalene and phenanthrene and the -vaj mixture is subsequently cooled to, cond water, the concentration of some of the n thalene and phenanthrene -vapours will be that the vapours of oil, -naphthalenephenanthrene -will condense together and naphthalene and phenanthrene will be hel solution in the oil This oil mixture -will out of the condenser with the water so tha high melting point hydrocarbons will solidify to clog the condenser As the wat T 2 O condensed in the condensers the concentrn of the high melting point hydrocarbon var in the acidic gases increases At the samethe temperature -of the vapours is grad -lowered in the condensers so that some melting point hydrocarbon vapours wil removed in each condenser Oil for disso the contaminants is supplied to the -va line leading to each condenser, through 43 and 53 and all condensed oil is collected : 30 withdrawn from the system This oil ca taken from a tank 47 and circulated throi line 50 by pump 51 into a vaporizer 52. Dil and water -which is condensed in the denser 21 is drawn off from the cond 7 r 35 through line 22 and-passed into a separate The oil and water stratify in the sepal -the water -being drawn off through a bc line 55 and passed into a receiving tanl the oil being drawn off through line A n 40 tank 60 This oil preferably is drawl through a -line 62 and may be used as fl for other purposes The water collectix the receiver 56 is preferably circulated ba the scrubber 4 to make up the dilute all f 45 absorbing solution This water is draw from the receiver -56 through the line -58 t pump:59. 1 Heretofore a vacuum pumps such as pur was deemed adequate for the entire sy -::50 Since the -vacuum of about 4 inches me Pressure absolute was readily maint thereby; there- -was no apparent reasoj modifring -the pumping system In accor with this invention, however, stean evacuating means are provided in series the vacuum pump to operate on vapoursof the pump According to one embod -of the inventionacondenser 21 is providec a Ljet evacuator 66 communicating with condenser -21 and actifier 12 and the rec substantial vacuum is maintained in the denser and actifier Steam is delivered evacuator:66 through line 67 The exha -mixed, steam and -gases, leaving the. .6:( 5-about -75-800 C, are passed through a -y 785,153 3 ar line 24 into a scrubber 25 The vapours pass able -through the scrubber 25 at about this temdro perature counter-current -to a stream of water boils which is introduced-into the condenser through r O C a nozzle 26 The volume of water used is -con t 170 1800 trolled to absorb, sufficient ammonia to prevent i oil resinifications of the -acid gases -in the further ning treatment thereof while avoiding substantial pour absorption of hydrogen cyanide from the Lense vapours ater containing ammonia is removed -75 aph from the scrubber through a line 27 When

such HCN is recovered the effective method of and operating is to use a -jet evacuator and a pump the as set forth -In other i instances two jet Id-in evacuators canbe employed -:80 flow The acid vapours leaving the scrubber 25 t the will be substantially free of ammonia This not ammonia free vapour flows through a line 28 -er is into a second condenser 30 where the temition perature, is reduced to about 25 'C and -the 85 Wours steam from the jet and water vapour remaining time with the acid -gases are condensed As the tually vapours enter the condenser 30 oil vapours high from the vaporizer 52 are introduced through 1 be the line -53 -into the vapour line 28 -to again 90 lving supply oil vapours to be available for dissolving pour any naphthalene or phenanthrene in the lines vapours The water and oil which are cond and densed in the condenser 30 flow through a line la be 22 to the separator 54 and these constituents,-C 95 igh a are separated, along with the water and oil The removed from -the condenser 21 con The vapours pass from the condenser -30 enser -through a line 31 which connects with a trap )r.54 23 for trapping out gany water or oil that may CI 00 rator, accompany the vapours The trap 23 is conDttom nected with the condensate line 22 Vapours k 56, then pass out of the top of the -trap 23 through 57 to a line 32 to a vacuum pump 33 where the presa off -sure is raised to deliver the vapours through a ^I-05 iel or vapour line 34 at a pressure of, say 5 to-10 -lbs. ig in gauge. ck to Previously, in passing through the vacuum kaline pump, the vapours were heated in-the range-of n off 1000 to 1500 C However, since the institution -1-10 zy the of this invention, based on the discovery that this high pump temperature promotes polymip merisation in the vacuum pump-and the line stem leading therefrom, the temperature-:of the rcury -Ha S and -HC Ngases leaving the vacuum pump 115 :ained is -now around 600 C Gas vapours now flow a for through vacuum pump 33 and line 34 to condance denser 35 without the formation of solid masses i jet which; tend to clog the pump and thee line with -leading therefrom -120 ahead While it is not absolutely essentials the iment vapours are normally -cooled in a condenser, 1 with for example -35, following the vacuum pump. -both When this is done, since -some high melting iuired point contaminants yet remain in the yapours, 125 con oil is introduced through a line-43 into the to jet;vapour line 34 The oil introduced-into-line usted, -34 is, of:the same type-oil that is vaporized in jet at -vaporizer 52, e g kerosene -This oil is introapour duced into a vaporizer 42 through a valved line -3130 41 andlive steam through aline 64 heats the oil. The water and oil collecting in the condenser are removed through a line 37 and pass into a separator 40 Water is removed from the bottom

of the separator through a line 45 and passes to a drain The oil flows from the separator 40 through a line 46 into a receiver 47 From receiver 47 the oil normally is with-drawn through discharge line 61 for purification or other use However, when only a small amount of high melting point contaminants separated in the condenser 35 is present the oil can be used for dissolving the high melting -point contaminants passing through the condensers 21 and 30 In this instance the oil is supplied through the line -50 to the vaporizer 52. The acid vapours, particularly hydrogen sulfide, hydrogen cyanide and carbon dioxide are delivered from the condenser 35 through a line 36 which may conduct the gases into the refining equipment for separating the constituents The hydrogen cyanide is preferably dissolved in a large volume of cold water to be separated from the hydrogen sulphide and CO 2 -The hydrogen cyanide may thenm be concentrated and separated from the water by distillation The process and apparatus for separating the acid vapours is more particularly described in prior Patent No 612122. : The above described process and apparatus is very effective in handling the problem of condensing a large volume of vapours of a liquid while also removing the vapours-of solid contaminants therein which so seriously affect the operation of the equipment In addition the invention as set forth herein is particularly adapted to the recovery of hydrogen cyanide. In connection with the embodiment of the invention illustrated in the drawing the steam jet evacuator while placed after the first condeaser need not necessarily be interposed at that point so long as it is followed by a condenser to condense the steam by which it is operated Thus-the steam jet evacuator can be placed before the condenser -or after the ammonia scrubber 25, if one is employed. Thus in accordance with this invention a reduction in the compression ratio of the vacuum actification pump has eliminated the excessive trouble in the vacuum pump and in lines carrying the recovered H S-HCN gases. The trouble could be overcome by too low a vacuum, but this would result in excessive steam costs to heat the actifier In the case of coke oven gas it is desirable to operate the process at a fairly high vacuum ( 4 to 5 inches of mercury absolute) -because at this vacuum the process can be operated with heat recovered from coke plant flushing liquor instead of steam from a boiler house As indicated hereinbefore, the process ofthis invention is in use commercially -for the recovery of H 2 S and HCN from coke oven -gas by hot-vacuum-actification A plant which previously was shut down every month or two has operated without shutdown for over ten months As a result of the steam jet evacuator employed according to this

invention, the. I vacuum pump now runs at only 40-45 RXP M -70 as compared with 180 R P M before the modification of this invention, and the compression ratio is about 1 to 3 as compared to a previous ratio of about 1 to 12 The actification vacuum pump no longer operates at the excessively 75 high compression ratio which generates sufficient heat to cause polymerization of actifier gases passing therethrough. The effect of the use of a steam jet evacuator according to this invention on -the efficiency of 80 hydrogen cyanide recovery was believed to be a possible disadvantage of the invention It was thought that condensing the large amount of steam from the H 2 S and HCN gases after the evacuator would cause the condensation and 85 -loss of HCN On the contrary, tests -showed that the loss from this cause was more than offset by a reduction in the amount of conden-sate from condenser 35, which previously contained HCN -Moreover, the larger quantity 90 of steam being now condensed after the steam jet evacuator leads to a more efficient removal of ammonia andpyridine bases fromthevapours before -they enter the vacuum pump Ammonia and pyridine bases, are undesirable 95 because they tend to promote polymerization reactions in the system. In the embodiment of the invention set forth in connection with the accompanying drawing the vacuum carbonate process is described in 100 connection with a coke oven gas having a temperature -of -500 to 650 C The vacuum carbonate process is, -however, also used to treat fuel gases having temperature different from those described The vacuum carbonate 105 process is also applicable to fuel gases containing acid gases, but which are more free of contaminants The formation of hard polymer in the vacuum pump occurs in either case, and is eliminated in accordance with this invention 110 -Thus variations in the process hereinbefore set forth can be made without departing from the scope of the invention With respect to changes in feed streams or temperatures, for instance, the vacuum carbonate process can 115 be carried out if desired without utilizing an ammonia washer such as scrubber 25 Also instead of employing two vaporizers 42 and 52 for oil used in naphthalene treatment three (one for each condenser) desirably can be 120 employed

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* GB785154 (A)

Description: GB785154 (A) ? 1957-10-23

Patient table for an x-ray installation

Description of GB785154 (A)

A high quality text as facsimile in your desired language may be available amongst the following family members:

BE530193 (A) DE1025563 (B) FR1108821 (A) NL92064 (C) US2771330 (A) BE542474 (A) DE1032476 (B) FR68334 (E) NL89681 (C) BE530193 (A) DE1025563 (B) FR1108821 (A) NL92064 (C) US2771330 (A) BE542474 (A) DE1032476 (B) FR68334 (E) NL89681 (C) less Translate this text into Tooltip

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The EPO does not accept any responsibility for the accuracy of data and information originating from other authorities than the EPO; in particular, the EPO does not guarantee that they are complete, up-to-date or fit for specific purposes.

COMPLETE SPECIFICATION Patient Table for air X-ray Installation We, SMIT RONTGEN N.V., a limited liability company organised under Dutch laws, of 32-34 Herengracht, Leaden, Holland, do hereby declare the invention, for - which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement :- This invention relates to a patient table for an X-ray installation and is an improvement in or modification of the table described and claimed in the specification of the co-pending application No. 20046/54. In the sai & specification there is described such a table which can

be tilted from the horizontal position in two directions by means of a moving mechanism about an axis arranged in its transverse direction at a height above the floor smaller than half the table length, to suca an extent that the plane of the table top is vertical and the table according to the said specification is characterised by a transmission member rotatably mounted on a support which is rotatable about the said axis and with respect to which the table is adapted to be displaced in its longitudinal direction which transmission member engages a toothed segment in the form af a sector concentric to the said axis and fixed on a base for the table, and a second transmission member coupled with the first-mentioned one engages a toothed rack arranged along the table; in sucha manner that on actuating at least one transmission member the first-mentioned effects the tilting of the table about the said axis and the lastmentioned the rectilinear displacement of the table with respect to the support in a direction opposite to the tangential direction of displacement of the first-mentioned transmission member with respect to the toothed segment in the form of a sector. It is an object of the present invention to provide an improved patient table of simple and robust coa,struc.tioa in which the co-acting -- parts of the moving mechanism thereof will not be overstressed so that any play due to wear is obviated and uniform movement of the patient table, without shock or vibration, is ensured for the Thil range of-the said table. According to the present invention the table includes an electric motor mounted thereon and means, movably mounted on said table and adapted to be actuated directly by said electric motor to displace the said table with respect to the said support in its longitudinal direction, a toothed segment, m the'form of a sector concentric to said axis and fixed to said base, having teeth on the inner circumference thereof, a toothed rack mounted longitudinally of said table and fixed thereto gearing comprising two pinions coaxially fixed to each other and rotatably mounted on said support, one of said pinions being engaged'with the inner circumference of said toothed segment and the other pinion being engaged with said rack, whereby actuation of said gearing due to said relative displacement effects tilting of the table about said axis in each of two opposite directions by action on saidtoothed segment and rectilinear displacement of the table relative to the support in a,direction opposite to the tangential direction of displacement of the table relative to the toothed segment. The said means movably mounted on said table and adapted to be actuated directly by said electric motor and to displace the said table with respect to the said support in its longitudinal direction,

preferably comprises a screw spindle adapted to be actuated directly by said electric motor aad rotataly mounted on said table in the longitudinal - direction thereof and engaging a nut fixed to saidsupport, The invention will now be described with reference to the accompanying diagrammatic drawings in which: Figure 1 shows the patient table'with'the principal parts of the moving mechanism in side elevation, one of the side walls of the said table being omitted. Figure 2 indicates a sectional view according to the line Il-Il in figure 1. Referring to the drawings the patient table includes a base 1, having an upstanding post 2 at one of its ends, said base extending in trans verse direction relative to the table, and a toothed segment 4 in the form of a sector having teeth on the inner circumference 22 thereof being mounted on the post 2 by means of a pivot 3 which toothed segment is rigidly:con- nected thereto by means of a bolt 5. Furthermore a support 7 is rotatably mounted on the pivot 3 supported in the post 2. In the side wall of the support 7 opposite the toothed segment 4 guiding slots 8 are arranged near its upper rim, in which slots rr g guiding member 9 engages, forming a whole Unit with a down wardly extending longitudinal rim 10 of the table. In the horizontal position of the table shown in figure 1 the guiding member 9 extends on both sides for some distance beyond the support 7. Near to the top 11 of the table a screw spindle 12 is arranged in thelongitudinal direction of the table which spindle is supported at its ends in bearings 13. This spindle may be actuated by means of a worm gear -14, by an electric motor 15. The screw spindle engages a nut 23 which is fixed to the support 7 near the upper rim of the latter. At a short distance from the upper rim ofthe table a toothed rack 19 is mounted on the table along said rim which toothed rack extends through the greater part of the length of the table and is parallel- to the screw spindle 12.

Furthermore two pinions 20 and 21 which are coaxially fixed to each other are rotatably supported on a shaft 17 which is itself supported by the support 7. The pinion 20 engages the teeth on the inner circumference of the toothed segment 4 and the pinion 21 engages with the toothed rack 19. The moving'mechanism of the patient table described above operates as follows: When the table is to be brought from the horizontal position shown in figure 1 into the vertical position; e.g. by tilting in a direction opposite to the clockwise direction the screw spindle 12 is actuated by the electric motor 15 in such a direction that the said spindle, owing to the coaction with the nut 23 moves to the right relative to the support 7. Since said screw - spiadle is rotatably mounted on the table but is not shiftable-in its longitudinal direction relative to said table, the table and the toothed rack 19 mounted thereon are moved to the right relative to the support 7. Since the pinion 21 engages the toothed rack 19 this pinion is rotated during the above mentioned movement about - its - shaft 17 in clockwise direction, the pinion- 20 fixed to the pinion 21 rotating in the same direction. Since the pinion 20 engages the teeth on the inner circumference 22 of the stationary segment 4, the rotation of said pinion 20 results -in its displacement along the said inner circum ference 22 in an anti-cIockwise direction and therefore the support 7, together with the table supported on said support, is tilted, by the intermediary of the shaft 17, about the pivot 3 in an anti-clockwise direction. In the above-described manner the tilting movement of the support 7, together with the table about the said pivot 3, causes a rectilinear displacement of said table relative to said support the direction of which is opposite to the tangential direction of displacement of the table relative to the toothed segment 4. The construction of the moving mechanism is

arranged in such a manner that the table may nevertheless be positioned vertically without abutting the lower end of the table in question on the floor. As is shown in figure 2 all parts of the moving mechanism with the exception of the electric motor are located within the width of the upstanding post 2 on one side of the table. Hence, since the electric motor is mounted on the table, a very large space is left below or behind the table for positioning an X-ray tube adapted to be displaced with respect to the table, which tube may in this manner easily be brought to all desired points for screening and exposures. It will be dear that the moving mechanism described may be altered in several ways as to the construction of the parts without departing from the scope of the invention. What we claim is :- 1. The improvement in or modification of the patient table described and claimed in the specification of the co-pending application No. 20046/54 which consists in the provision of an electric motor mounted on said table, means movably mounted on said table and adapted to be actuated directly by said electric motor and to displace the said table with respect to the said support in its longitudinal direction, a toothed segment, in the form of a sector concentric to said axis and fixed to said base, and having teeth on the inner circum ference thereof, a toothed rack mounted longitudinally of said table and fixed thereto, gearing comprising two pinions coaxially fixed to each other and rotatably mounted on said support, one of said pinions being engaged with the inner circumference of said toothed segment and the other pinion being engaged with said rack, whereby actuation of said gearing due to said relative displacement effects tilting of the table about said axis in each of two opposite directions by action on said toothed segment, and rectilinear dis

placement ofthe table relative to the support in a direction opposite to the tangential direction of displacement of the table relative to the toothed segment. 2. A patient table according to claim 1 in which the said means movably mounted on said table and adapted to be actuated directly by said electric motor and to displace the said

* GB785155 (A)

Description: GB785155 (A) ? 1957-10-23

Improvements in or relating to explosive charges

Description of GB785155 (A)

A high quality text as facsimile in your desired language may be available amongst the following family members:

DE1148926 (B) FR1145210 (A) US3100445 (A) DE1148926 (B) FR1145210 (A) US3100445 (A) less Translate this text into Tooltip

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The EPO does not accept any responsibility for the accuracy of data and information originating from other authorities than the EPO; in particular, the EPO does not guarantee that they are complete, up-to-date or fit for specific purposes.

PATENS P IC PATENT SPECIFICATION Inventor: THOMAS CHA 4 RLES POULTE 4 " '| t Date of Application and filing Complete Specificat, No 31756/55. Complete Specification Published: Oct 23, 1957. R # ion: Nov 7, 1955. t 85, 155 Index at acceptance:-Class 9 ( 1), C 1 A 3.

International Classification:-FO 7 f. COMPLETE SPECIFICATION Improvements in or relating to Explosive Charges ERRATUM SPECIFICATION No 785,155 Page 1, line 31, for " f a " read "of a" THE PATENT OFFICE, 21st April, 1958. metallic, such as copper, steel, cast iron, aluminum or lead;, or may be of glass or other non-metallic material The cavity and liner are usually conical, hemispherical, or conforming to other surfaces of revolution about the longitudinal axis of the charge. Provision is made for initiating detonation of the charge on its axis at its rearward end. Upon detonation f a conventional shaped charge, a detonation front advances through the charge in the direction of its major axis and impinges on the liner By virtue of the extremely high particle velocities and pressures prevailing in the detonation front, the major portion of the liner is dynamically extruded in a pencil-like jet along the charge axis at extremely high velocity. 'Because of the great penetrat ng power of this high-velocity jet, many applications, both militasry and industrial, of the shaped charge have been developed An outstanding example of an industrial application is in the perforation' of well casing and subterranean formations surrounding oil, gas and water wells. Since its original development as a military other theories tplastic c Letormation anct orrnt fracture) so that when one considers that it is possible to have the formation of the jet follow any one of three mechanisms;, plus all possible combinations of these, it is not surprising that much confusion has resulted. The problem is further complicated by the fact that there are no independent variables. It is generally recognized that the size, shape and composition and thickness of case surrounding it, the shape, thickness, and composition of the liner, stand-off distance, method of detonation of the charge, shaping of the detonaation front, and the angle that the detonation front makes with the surface of the liner are all known to materially affect the performance of shaped charges. There is, however, not a single one of these variables which can be considered to be an independent variable On the contrary, the changing of any one of them changes an unknown number of the others, usually by an undetermined amount, so that without a rather clear understanding of the detonation process and the possible mechanisms of jet formation, iv i PATE Date of Aj Complete Index at acceptance:-Class 9 ( 1), 1 International Classification:-F 07, Improveme: NT SPECIFICATION r: THOMAS CHAR'LES POULTER pplication and filing

Complete Specification: Nov 7 i 1955. 78 C 5,155 Specification Published Oct 23, 1957. COMPLETE SPEGIFICATION nts in or relating to Explosive Charges We, BORG-WARNER CORPORATION, a corporat O i:on organised under the laws of the Sitate of Illinois, United States of America, of 310 S'outh Michigan, Avenue, 'Chicago, Illinois, United States of America, 'and WELEX JET SERVICES, INC, a corporation organised under the laws of the State of Delaware, United States of America of 1400 East Berry Street, Fort Worth, Texas, United States of America, do hereby declare the invention, for which we pray that a patent may be granted unto us, and the method by which it is to be performed, to 'be piarticularly described in and by the following statement:- This invention relates generally to explosive devices and is directed particularly to improvements in shaped charges The term " shaped charge," 'as used herein and as generally employed in the art of explosives, designates a charge of high explosive having a cavity in its forward end which is lined with a layer of inert material The liner may be metallic, such as -copper, steel, coast iron, aluminum or lead, or may be of glass or other non-metallic material The cavity and liner are usually conical, hemisphfericalo or conforming to other surfaces of revolution' about the longitudinal axis of 'the charge. Provision is muade for initiating detonation of the charge on its axis at its' rearward end. Upon detona'+ionl f a conventional shaped charge, a 'detonation front advances through the charge in the direction of its major axis and impinges on the liner By virtue of the extremely high particle velocities and pressures prevailing in the detonation front, the major portion' of the liner is dynamically extruded in a pencil-like jet along the charge axis at extremely high velocity. 'Because of the great penetrating power of this hi'ghvelocity jet, many appliications, both military and industrials of the shaped charge have been developed An outstanding example of an industrial appplication is in the perforation of well casing and subterranean fonrmations surrounding oil, gas and water wells. sintce its original development as a military weapon, the shaped charge has been the subject of extensive research, both analytical and experimental For the most part, experimental 50 research has been conifined to cut-and-try procedures, and analytical research has been confined to the study of experimental' data and the development of theories of the mechanism of jet formation which are consistent with and 55 attempt to explain such data 'Many conflicting and erroneous theories and explanations of the mechanism of jet foarm ation have been advanced. The mechanism of jet formation from a 60 lined hollow charge is very

complex, and there is probably no single explanation that will' explain all of the experimental results to the exclusion, of, all, other proposed theories. The most widely publicized mechanism is 65 referred to as the hydrodynamic flow mechanism (Journala of Applied Physics 1; 9, 5,63 1948) There are extensive experimental results to substantiate at least two other theories (plastic deformation and brittle 70 fra'cture) so that when one considers that it is possible to have the formation of the jet follow any one of three mechanisms, plus all possible combinations of these, it is not surprising that much confusion has resulted 75 The problem is further complicated by the fact that there are no independent variables. 1 It is generally recognized that the size, shape and composition and thickness of case surrounding it, the shape, thickness, and coin 80 position of the liner, sitand-off distance, methbd of detonation of the charge, shaping of the detonationl front, and ithe angle that the detonation front makes with the surfaice of the liner are all known, to materially affect the 85 performance of shaped charges. There is, however, not a single one 'of these, variables which can be considered to be an independent variablbe 'On the contrary, the changing of any one of them changes an un 90 known number of;the others, usually by an undetermined tam'ount so th withouta rather clear understanding of the detonation process and the possible mechanisms of jet formation; -3 1 11 it is impossible to predict the performance of a new design of shaped charge, It is not surprising, therefore, that most of the development work to dete has been conducted on a cut-and-try basis with usually very discouraging and inconclusive results. To develop a set of rules for the design of an effective lined shaped charge based on so many interdependent variables would, of course, be impossible A fundamental study of the detonation process and the mechanism whereby a metal liner is given, its velocity when an explosive in contact with it is detonated, was therefore undertaken In this manner a few least common denominators have been obtained which provide some useful design parameters. From this-it has been possible to evaluate the relaions between the shape of the detonation front and-the detonation veloucity,,and the relation between the detonation velocity and the detonation pressure Still further studies of the detonation process permit an evaluation of -the factors controlling the duration of the pressure associated with the detonation, process This' pressure and its duration provide a means of determining the impulse imparted to -the liner This, coupled with the design of the liner, provides a means for determining the direction and velocity of the motion imparted to the various elements

of the liner Thus, it has been possible to better understand the complexity of jet formation and its control, which has resulted in the invention and development -of -a basis design of a shaped charge having vastly improv ed performance characteristics In the usual cut-and-try procedure there has been but little, if any, basic information on which to arrive 'at a modification of the construction of a charge, nor was there any basis for knowing whether the change in perforinance was a result of the variable which was intentionally changed or whether one of the dependent variables dominated any change there may have been in performance It was therefore a matter of changing an unknown number of variables by an indeterminate amount to produce aan accumulative effect that may be positive or negative. From a knowledge of jet penetration it is possible to specify certain desirable properties of aa jet and, with this as a basis - to establish many of the requirements for a jet-producing mechanism and through that to produce an effective charge design. For good performnance, the material in the jet should be concentrated into a compact, straight -line jet of material 'moving -at highvelocity and having high density There should be ar-maximum range inr material velocity in the jet -consistent with its having the highest attainable material velocity at;the forward end of the jet, and decreasing at a reasonably uniform rate over the length of the jet to the minimum velocity that will produce effective penetration. The necessity for this spread in jet velocity is to permit each element of the jet to complete its penetration of the target before the 70 following element strikes the target. Other things being equal, an increase in velocity of the forward end of the jet will increase the penetration of the jet This is a very important factor since the percentage in 75 crease in penetration greatly exceeds the percentage increase in jet velocity necessary to produce it. It is entirely possible that an increase in the average velocity of the -material in the jet 80 may reduce the penetration if that increase in velocity occurs primarily at the after-portion of the jet In such a case each element of the jet would be striking the target before the preceding element had completed its pene 85 tration, and the piling-up effect may cause a large decrease in depth of penetration of as much as 75 percent, with only a minor increase in hole diameter The extent to which the after-end of the jet can have its velocity 90 increased is determined by the ability of each preceding element -to complete its penetration. In order to obtain maximum penetration, the forward end of the jet should have the maximum obtainable velocity and each successive 95 element should have the maximum velocity consistent with permitting

the preceding element to complete its maximum penetration of the target before the succeeding element strikes 100 With such specifications set up for an effective jet, it then becomes a matter of selecting the mechanism of jet formation and the charge design which will best lend itself to the produdtion of such,a jet 105 While it is possible to design a lined shaped charge operating by a mechanism of jet formation whereby the -high velocity forward end of the jet originates from -the base of the liner, 'such a design does not pernit taking 110 advantage of certain novel' features of the present invention. From experimentation: in which a conventionual charge was modified in such a manner as to increase the velocity of the after-end 115 of the jet by only a small amount, it was found that an appreciable decrease in penetration resulted From this it was obvious that if any appreciable increase in penetration was to be accomplished, it would have to be 12 C through an increase in the velocity of the forward end of the jet This meant devising techniques for inicreasirii the velocity imparted to the metal of the apex of the -liner. Numerous attempts have been made to do 12 ' this by means of peripheral detonation of the charge -with generally unsatisfactory results, either because of the requirement of an excessive quantity of explosive or, if the quantity of explosive were reduced, because 13 ( 78-5,455 wide a shaped charge Wherein the shape of the detonation front is altered in' a predetermined manner by a body of inert material embedded in, the explosive charge. Yet another object of the invention is to 70 provide a shaped charge wherein the size and shape of the hole produced in a target may be predetermined solely by the relative positions of certain of the charge components. -Another object of the invention is' to pro 75 vide a 'shaped charge incorporating a body of inert material embedded in the explosive charge, -and wherein the size and shape of the hole produced in a target may, be varied' in predetermined manner by varying the distance 80 between the inert body and the liner. -A still further object of the -invention is to provide a shaped charge wherein, upon detonation, a detonation front is developed in' the explosive which is characterized by a cen 85 tral concave front and a peripheral or 'annular convex front. Still another object of the invention is to provide a shaped charge incorporating means for developing, upon detonation, a central 90 detonation front;and an initially separate and distinct peripheral detonation front, the time and space relation of the two fronts being such that they merge into;a composite front having a concave central portion characterized 95 by extremely high order pressure and particle

velocity. Yet another object of the invention is to provide a shaped charge wherein the optimum stand-off distance from the base of the liner 100 to the target is substantially less than with charges heretofore developed. -Still:another object of the invention is to provide a shaped charge -wherein the mechanism of jet formation is such that the degree 105 of interdependence of the various parameters of the charge is substant'ally less thank in charges 'heretofore developed. A still further object of the invention is to provide 'a shaped charge wherein' the usual 110 slug -or "carrot" may, if desired, be substani?ally eliminated. Generally speaking, based on our studies of detonation phenomena, we have discovered and developed an' arrangement add procedure -or 115 technique whereby a detonation front of abnormally high pressure land velocity can be developed in the explosive charge rearwardly of the lher, with the 'central portion of the front being concave and conforming in shape 120 very closely to that 'of the apex portion of the liner This is accomplished by developing 'a combined peripheral:detonatidn front and central detonation front in predetermined itime and:space relation to each other and to the 125 apex portion of the liner The merging of these detonation fronts produces a composite front in which the pressure 'and' the detonation velocity greatly exceed the sum of the individual pressures 'and velocities of'the two 130 the meeting ef the converging detonation, front' over the apex of the liner would blast a hole through 'te liner along its 'axis and disrupt Hits normal jet formation It is our discovery, however, that if the inert barrier 'by which peripheral detonation is generated is so constructedl as to permit a delayed detonation to occur through its central portion, then, instead of the converging peripheral detonation front meeting at the centre and blasting a hole through the apex of the liner, it will meet the delayed expanding detonation front in, a circular area generally:surrounding the apex of the liner and a generally spherical concave detonation front is developed which envelops the apex of the liner in a pressure manifold the sum of the pressures in' the two detonation fronts. Thus the forward end of the jet acquires a velocity far-in excess of that produced by the conventional expanding spherical detonation, front produced 'by single-poninitiation. Due to the more nearly normal angle of approach of the peripherally generated det'ona25,tion front over the cebtral portion of the liner, the velocity over the central portion of the jet will be correspondingly increased This will therefore permit;an increase in

the after portion of the jet, and hence the ratio of explosive to metal 'around the base of the liner can 'be increased over and ilabove that whichis permissible with the single-point-initiated charge We have discovered that the invention provides another very important advantage in that merely by a small shift in position of the apex of the liner closer to' or farther away from the inert barrier, the diameter of the hole produced by the jet from this charge can be varied over a several-fold range, the maximum:size hole being produced with the liner at the proper distance to cause the detonation front to conform in curvature to that of the liner apex. A general object of the invention is therefore to prov Ide an improved shaped charge the performance of which is characterized by more effective utilization of the energy available in the explosive than has heretofore been possible. Another object of the invention is to provide an improved shaped charge which, upon detonation produces a jet of higher overall velocity than' has heretofore been attained. A' further object of the invention is to provide an improved shaped charge which not only produces 'a higher velocity jet than heretofore, but which is so designed' that the velocity of successive elements of the jet is distributed over a range of velocities' sufficiently wide to permit each element of the jet to most effectively expend its energy in efecting penetration, of the target before the next succeeding element strikes the target ' Another object of the iniventioni -is to' po785,155 fironts Not only is it possibleitol "tailor-" the shape of this composite front to 'conform substantially lto liner apices of different curvatures, but it is also possible with the improved charge design to produce ag wide range of target hole sizes with the same liner shape, by the simple -expedient of slight changes an the position of the liner, involving merely a slight change in loading technique. -The manner in which the foregoing and other objects may be accomplished will become -apparent from the following detailed description of a presently preferred emibodiment of the' invention, reference being had to the accompanying drawing wherein: Figure 1 is a -central longitudinal sectional view of a shaped charge embodying ithe invention; and Figure 2 is an enlarged view similar to Figure 1, illustrating successive -stages of propagation of:the individual detonation fronts, their-merger into a single composite front, the progressive change in shape of the composite front and its impingement onn the apex poriion' of;the liner. Referring to Figure 1, a charge case 1 is heremi shown as cylindrical but'may be of any other desired shape symmetrical with respect to the charge axis, and is preferably of metal siuch-aissteel, cast-iron or

aluminunm but may if desired be xof non-metallic material such as any of the commonly used plastics. A liner 2 of co pper or other suitable material is mounted in the case in a convenitional manner As shown, the apex portion 3 of the liner is rounded and the side pordons of the liner are of gradually decreasing curvature It will be understood, however, that the specific shape of the liner does not constitute a significant aspect of the present invenio 6 N and various other shapes' may be employed if desired. Rearwardly of -the liner the case 1 is filled with an explogive' 4 having a high detonation rate, such as TNT, Cyclotol, -etc Enibedded in the explosive 4 'adjacent the rear wall of the case is a barrier 5 of inert -xtate 6 i 1 al 'uch as steeli or other mnetals or' non-metvals The barrier 5 is disposed transversely of the charge and is syinmetrmcal and coaxial with the case and liner As shown the barrier S-is of unifbrm thickness and is preferably in the -irm of a segment of a sphere, although ofher shapes which are symmetrical -viith the - axils of the charge may' be employed, such as 'conical; p-irabolo'idal,-ellipsoidal, or a fliat disc -The diameter-or transverse dimension of the barrier is less than the inmte naldiamrt&r of the case 1 tfhereby'providing an annulus 6 'of explosive surrounding the periphery of the barriler and joining 'the bodies of exlosive at the forward and rearwatd sides of the -barrier In ordei to 'proide a -layer of explosive '7 of uniform thickness -between the barnier iand the rear wall 8 ' of the case I, the latster is-prefeiably a Iso' inr the form of a segment of a sphere or of other shape conforming to that of the barrier. A tubular socket 9 projects from the rear wall W of the case 1 in coaxial -relation thereto, and is perforated transversely tat 10 to receive 70 a length of Primacord 11 or other detonating fuze A booster pellet 12 is seated in the socket 9 between the l Prim'acord 11 and the rear wall of the case, and is in direct contact with the explosive 7 through an opening 75 13 in the rear wall 8, it being understood that the explosive also fills the opening 13 The opening 13 should be small enough toe assure concentricity of the, detonation front. - It will be apparent that detonation of the 80 Prin-a-cord 11 will detonate the booster 12, which in turn initiates detonation of the explosive 7 at the opening 13 Referming to Figure 2, the detonation front developed at the opening 13 initially expands spherically 85 until it strikes the rear wall of the barrier 5, whereupon it is converted into a radially exp'anding circular front progressing through the layer 7 of explosive, successive positions of the front being indicated at 15, 15 a and 90 b. Upon reaching the periphery _of-the barrier, the detonation front progresses therearound and forwardly through the annulus 6 of

explosive. As it passes the forward peripheral edge of 95 the -barnier and enters the main body of explosive 4 it is free to expand both forwardly and radially inwardly toward the axis of the charge Hence, the forward and inward portion of the front assumes the form of a portion 100 of the surface of a torus, as indicated by the corresp'onding pairs of arcuate detted lines -16, 16 and 1 '6 b. Meanwhile the detonation of the explosive in contact with the rear surface of the barrer 5 105 has generated a shock pulse in, the material of the barrier This -shock pulse, initiated at a point on the axis of the charge, progresses forwardly through' the barrier as indicated at 17; -17 a 1 % 7 b and 117 c, to the forward, con 110 cave surface thereof Also, as the detonationi front indicated at 15, 15 a and 15 b expands through the explosive layer 7, it rolls along ithe rear surface of the barnier 5 and generates -a radically progressing series of shock pulses 115 in the 'barrisr, which -progress forwardly ithrough the barrier Whether'or not the explosive in contact with the forward surface of the barrier 5 will be detonated by the shock pulse transmitted 120 through the harrier, and wiether the detonaton 'is,low rdr or high-order, depends, generasly Apeaking, on the intensity of the shock pulse-as it reaches the forward, surface of the barrier and on the sensitivity of the 125 explosive in contact-therewith The intensity of -the shock pulse 'after it passes through the barrier depends on the material of the-barrier, the thickness of the central portion thereof, and the thickiess of' the central portion of the 130 -4 -78,5155 verging peipheraal detoniation front ialone (condition (ua) abbve) is not conducive to' proper jet formation The salpex of the liner is not the first portiion 'of the liner,to be given, a velocity las is the case with single-point detona 70 tion Instead, the detonationi front first contacts a ring of material farther down on the liner. Since this first contac iis normal sto the surface, that portion of the liner will be given a high velocity As the detonation, front rolls 75 along the surface of the 'liner in the direction of the apex, the angle of approach becomes less than 90 and the material is given a lower velocity than the portion of the liner irst,contactedi This lower-veel'odity material is 80 projected into the region, where,the jet is being formed and dislturbs the jet formation. However, as the detonation front reaches the apex, it 'converges aand meets at a point Such a meeting of detotnation fronts produces, at 85 that point, a pressure estimated to be in excess of fifty million psi With such a pressure at a point, a jet of extremely high-velocity material is projected into the zone where the jet proper is being formed, and since the lower 90 velocity material has already been

projected into that zone, the collision of the extremely hilgh-velocit material With it tends 'to disrupt the process of jet form'asion Although the process of jet fionnaltion proceeds in'an orderly 95 manner in' the lower portion of the liner,,the disturbance in the formation of the 'apex of the jet has been such as to prevent its superior performance This interference cann be prevented wo some extent if the distance between 100 the zone of peripheral initiation and the apex of the liner is increased, which, accounts for the belief that in order for peripheral detonaflon 'to funetion properly, an excessive amount of explosive is required 105 We have discovered that if conditions are such as' to produce a high-order central detonation front and a high-order peripheral detonation front, the 'collision, of two such high-order fronts produces a sharply defined, 110 annular zone of extremely high pressure If the liner be located close enough to the barrier to subject any portion of the liner to the effect of this sharply defined, annular high-preissure zone, there results 'a miarked 115 decrease in the effectiveness of the jet, Thisis iattributed to the sharp' boundary-cutting effect of the annular high-pressure zone on the liner, producing a sharp discontinuity in the velocity gradient of the jet '-On the other 120 hand, if the liner be 'located far enoujgh away' from the barrier to avoid fthe sharp boundary-. cutting effect of the hiih-,order detonation collision zone, the perforutance of the charge is strikingly sinilar to that of a 'conventional 125 charge having single-point initiadon; This indicates that the axial, spacing between the iner and,the' blarrier is so greqat that' the initially centrally concave detonation front has been, c 6 fiverted t o a conventionlal convex'front 130 layer 7 of,explosive which generates the shock pulse. By way of example, in tesrts wherein the explosive used was waxed " R 1 DX," a military form of cyclonite (CH, N NOZ), it has-been determined that with a barrier 5 of steel and with a 1/116 inch thick layer 7 of explosive which is detonated by 'a booster such as the pellet 1-2, if the (thickness of the central pordon of the blarrier is 3/116 inch or greater the explosive Iin contact with the forward surface will noat be detonated by the shoeck pulse If the central portion of,the barrier is 1/10 inch to 1/8 inch in thickness, the shock pulse transmitted through it will initiate,low-order detonation' of the explosive at the forward side of the barrier If the central portion of the barrier is substantially less than 1/10 inch in thickness the shock pulse will init ate highorder detonationa of the explosive at the forward side thereof. On the other hand, fronm tests with charges in which the type of explosive, the material and thickness of the biarrier 5, and the

thickness of the layer 7 of explosive were identical with those referred to in the preceding para-graph, but in which the booster pellqt 7 was omitted and detonatilon was initiated directly by Pimacond, Dit was found thlat the optimum barrier thickness from, the standpoint of depth of penetration, was 0 0,59 inch, as compared to 0.10 to 0 12,5 in the previously mentioned test results This may be explained by the fact that,the booster pellet 12 constitutes Iin effect an additioniall thickesis df explosive behind the centra'l portion of the barrier This points up the important influensce which the thickness of the explosive exerts on the initial velocity of the shock pulse developed in the biarier. It is thus apparent that by the selection of. a barrier of appropriate material and thickness, or by varying the effective thickness of the explosive behind the barrier, any one of three distinctly different detonaltion, front conditions may be produced in, the explosive forwardly of the barrier-(a)l a converging, highorder peripheral detoniation front only; or (b) a converging, high-order peripheral detonation front and a: delayed, expanding, low-order' central detonation front; or,(c), a converging, high- order peripherall detonation front and a delayed, expanding, high-order central detonation front. The respective chiaraitenitics 'of the two distinct types of detonation known, as "highorder"'" and " low-order " detonation are well known, t O those familiar with explosives and have been delineated in many publications dealing 'wth explosives A Mw-known example of such 'publications is " Detonation in 'Condensed Explosives " by J Taylor, Oxford Press, 1952, London, England An explaination and discussion 'herein of those phenomena is therefore not deemed necessary. As has been',pointed out previously, a con7855,15,5 1 i L_ ibefore it reaches the apex of 1the liner, and hence that the advantageous effect of the bai: & er has been dissipated, It r therefore appears ghatt less advantageous results are tained When the parameters of the comnponents of a barrier e charge are such as to produce central and peripheral detonation fronts which are bpth of' high-order. One of the ro St importan and most significant -aspects of he invention is our discovery -that with the proper relationship between the type -of elasjve, _the barrier material and thickness, Band the thickness of explosive behind the central portion of the barrier to develop, alovw-order central detenttion front ardd a ingh-ordcer-peripheral detonation font at the forward side of the barrier, marked and unprecedented, improvements in charge performance from any standpoints, as well as several otthers outstandmg advantages, Cana be achieved These improvements and advantages, which

will be explained more in detail hereinafter, are brieflyi as follows: (a) greatly increased udepth -of target penetration and volume of target hole for a -given asmount of explosive; (b) wide variation in The cross-sectiona area of thetaxgert hole by vaying only the amount of explosive while maintfaining all other components the sarne; (c) substantial reduction in the number of parameters which effect performance, ma-king possible the development of a sirple equation deig,the relationship -of the significant parameters; (d) substantial reduction in optimum standoff distbiace (from base of liner tto target) ' = (e) substantial ' elimination of the usual slug or "'carrot " The mechanism of development of the in-tially separate, low-order centrall detonationfront and high-order peripheral detonation front, their merger into a composite front havigg a concave central region, and the progressive change in the contour of this front, will be made clear 'by reference to Figure 2 of the drawing as shown therein, the dot-anddash lines 118, 18 a and 1 Sb represent successive positions of the low-order expanding central detonation front initiated by the shock pulse transmitted through the barrier 5 The meeting of this front with the converging peripheral detonation front, indicated at -16, 16 a aitd 116 b producea a composite front which initially -comprises the, portions 16 b and 118 b. The juncture of the central front 18 b with the peripheral front 116 b initially produces an' Minnular, sharply concave region indicated at 19, wherein the radius of curvature is very small and the pressure and the particle velocity are considerably higher than at other points on the composite front Consequently this por tion of the front has a greater velocity than ithe remainder of the front, resulting in a pro 65 gressive increase in radius of curvature in that region It will be observed that the peripheral portion 16 b of the initial stage of the composite =nt is considerably in advance of -the central 70 poutio 118 b This results from the cumulative effeqt of -5-everal' time-delays occurring in,the generation of the central front 18 b The first tinme lag occurs in imparding velocity ito the surfawce particles of the barrier 5 at the inter 75 face -with the explosive layer 7, to generate the shock pulse 1 W 7 Another time-delay is the result of the lower velocity of the shock pulse 1 i 7 In comparison' with that of the high-order detonation pulse travelling through the explo 80 sive around the barrier The shock pulse velocity in a steel barrier is only, about onefourth that of the detonation pulse Consequently the successive positions of the shock pulse front indicated at 17, 17 a, 17 b T and 17 c 85 approximately correspond respectively to the positions 15, 1 ia, 15-b, and'16 of the detonation front. n Another time-delay occurs in the initiation of detonation of the explosive;at the central 90 forward side of the barrier 5 by the shock

pulse Lastly, if the barrier is such as to cause the shock jpulse to 'generate low-order detonaton of the explosive, the considerably lower vielcity of the low-order detonation pulse will 95 cause an additional tiime delay Thus, the locafion of the low-order detonation, front indicated at 18 will correspond in time 'to that of the shock pulse front indicated at 1 f 7 e which, as stated above, corresponds to the location of 100 -the peripheral detonation front indicated at 16.-As the front 118 moves successively to the positluons 18 a and 18 b, the front 16 moves to the positions 16 aiand 16 b. It will be understood that the aforemen 105 tioned time-delays are of infinitesimal order, but nevertheless sufficient to cause the formation of a composite front such as, 16 b, 18.b having a peripheral portion 16 b in advance of its ceatraliportion 18 Zb 110 An important and, advantageous characteristic of the meeting of a low-order central detonation front and a high-order peripheral detonation front is that it does not produce a sharply -defined extremely high pressure 115 zone as, in the case of the collision of two high-order detohation, fronts Instead, of a sharply defined, annular zone of extremely high pressure resulting from the collision of a high-order, expanding central detonation 120 front arid a high-order, converging peripherali detonation front, which, as stated previously produces a sharp boundary-cutting effect, the meeting and merging of a low-order central detonation front with a high-order peripheral 125 detonation front produces a zone of considerably lower pressure, distributed over the entire central area of the resulting composite 7,8 X 5,155 785,155 T front This distribution is the result of a merging, as distinguished from a collision, of the two fronts. As the composite front advances toward the apex of the liner 2, the concave annular region 19 which joins the central portion with the peripheral portion gradually flattens out and eventually merges: with the central and peripheral portions to produce a concave-convex front, as indicated successively at 20 and 21. At a certain distance forwardly of the barrier 5, this front has a central concave portion substantially conforming to the curvature of the spherical apex portion of the liner 2, as indicated at 22 In the illustrative embodiment the liner is positioned with its apex at the proper distance from the barrier 5 ' to achieve this conformity Accordingly, the entire spherical apex portion of the liner is subjected simnultaneously to the extremely high pressure and velocity of the concave central portion of the detonation front A relatively large portion of the liner is therefore concentrated in the forward, maximum velocity portion of the jet This is in striking contrast to the jet formed by a charge in which detonation is initiated at a single point and; the convex detonation front travels along the axis

and strikes the apex of the liner In the latter case only a relatively small amount of the material of the liner is concentrated in the forward, maximum velocity portion of the jet. Inasmuch as the particle velocity at any point on the detonation front is a maximum in a direction normal to the front at that point, as indicated by the arrows 23, and' inasmuch as in the arrangement shown in Figure 2 each point on the central concave spherical portion of the front impinges on the apex of the liner in such normal direction, the maximum velocity is substantially simultaneously imparted to the lentire mass of that portion of the liner As the detonation front advances beyond the last position shown in Figure 2, the angle of approach of the front to the side portion of the liner progressively decreases from 90 Other factors being equal, thisi serves to reduce the velocity imparted to successive portions of the liner material Further-more, the thickness of the explosive, measured normal to the surface of the liner, decreases forwardly and has a further reducing effect on the velocity imparted to successive portions of the liner The desired velocity gradient along the jet is thus attained, while still providing an average velocity considerably higher than Weight of Explosive (grams) 19 23 26 that obtained previously, 'by virtue of the extremely high velocity of the forward' portions of the jet, By virtue of the higher pressure and velocity of a concave detonation front, as compared 'to that of a planar or convex front, the curvature of the central concave portion 22 of the front decreases as the front advances beyond the last position shown in Figure 2 Hence, if the liner 2 were positioned with its apex farther from the barrier 5 the concave central portion of the front would' be of less curvature than that of the apex of the liner at the instant of impingement of the front on the liner apex, Consequently the front would strike the liner first at a point on the axis of the charge, followed by successive impingement over an 'expanding spherical area of the liner apex. Conversely, if the liner 2 were positioned closer to the barrier 5 than as shown in Figure 2, the curvature of the central concave front would' be greater than, that of the liner apex and consequently the initial contact of the detonation, front with the liner apex would be along a circular concentric path spaced from the axis In each of these instances the portion of the liner forming the forward' portion of the jet would, be extruded in a mass of smaller diameter than under the condition shown in Figure 2, and a smaller hole would be formed in the target, It is thus apparent that the target hole size may be varied over a considerable range by the simple expedient of varying the axial distance between' the 'liner and the barrier, and using identical charge components except for a variation in the amount of explosive. This is an important and highly advantageous feature of the present

invention. The foregoing statements concerning varnation of target hole size have been confirmed experimentally Numerous tests have 'been conducted under simulated oil well conditions, wherein the targets were sections of well casing of 375 " wall thickness, surrounded by aged cement simulating oil'-bearing rock formation? such as sandstone or limestone Typical results are shown in Table I below, which shows a 'comparison of target hole sizes obtained in the well casing with charges which were identical except for variation of the qxial distance between, the liner and' the barrier and, a corresponding variation in the amount of explosive. TABLE I. Dia of Hole _ Depth of Penetration in Well Casing in Formation, (inches) (inches) 462-.550 740 437 375 9.1 9 8 65 A 9.5 9 0 Volume of Hole (cu in) 3 1 3.67 4 25 2.50 3.00 so 7855,155 The charges used in the foregoing and numerous other tests are typical Of charges which have been developed embodying the present invention, and in which emphasis has been placed on the diameter of the hole produced, in the target, rather than on obtaining maximum penetration irrespective of hole size 3 By way of example, structural details, of the charges -used in the tests referred to above are given as follows: The case 1 is of standard 14 inch inside diameter steel tubing of 1116 inch wall thickness, the rear wall 8 being formed of 11 gauge steel plate pressed with, a 2 inch ball to a 1-1/-8 inch radius of curvature and welded to the end of -the case The booster socket 9 is welded to the rear wall 8 and is of a suitable size and shape to accommodate the particular type of booster pellet 12 to be used. The 'barrier 5 is made from circular blanks of 11 gauge steel, pressedn with a 2 inch ball to a L inch radius of curvature, The liner 2, of copper, has a 50 included angle with a apex radius of curvature on the inside of j-25 inch and a uniform wall thickness of 0 030 inch, The outside diameter of the base of the liner is about 0 003 inch larger than the inside diameter of the case, thus' providing an interference fit to hold the liner snugly in position whent pressed, into the case. The explosive charge 4 and the layer of explosive 7 rearwardly of, the barrier 5 are waxed, granular "RDX " pressed to 10,000 psi The loading operation is performed in two steps-ifirst, 4 grams of explosive are pregsed to form the layer 7, about 1116 inch in thickness; the barrier is then inserted andthe remainder of the charge is then loaded and pressed The liner 2; is then pressed into snug contact with the main charge The quantity of explosive in the main charge 4 willy vary in accordance with the target hole size desired 4 as pointed, out hereinabove In -the tests from which the results' given in Table I

above were obtained, the explosive weights of 15, 19, 23, 26 and 29 grams represent the total amount of explosive including the 4-gram layer 17 It should be pointed out that it -is not necessary to directly determine the axial distance between the barrier -5 and, the apex of the liner 2, inasmuch as this distance is relative and is indirectly determined by the amount of explosive in the main charge 4 It is, however, necessary to determine experimentally the performance data of a charge of a particular design An important characteristic of shaped charges embodying the present invention is that by virtue of our newly developed and entirely different mechanism of jet formnationf, the number of variables which materially affect charge performance, and which are changed 'by unknown amounts by changing other -variables, has been greatly reduced 'For example, an, analysis of a large quantity of test data involving identicallydesigned charges of different sizes has revealed that the ratio of the depth of penettation to the base diameter of the charge liner is fairly constant over a reasonably wide range of base diameters of the liners This ratio, which is an effective criterion of charge performance, may be expressed by: K = Pd( 1) where: P depth of penetration of the target; d=base diameter of the liner; and K=ratio of depth of penetration to' base diameter of the liner In a series of -identically-designed charges of different sizes, the weight of explosive is proportional to the cube of the base diameter of the liner; or W=Wd' or, expressed differently, C= W/d' ( 2) ( 3) where: W=weight of explosive; C=weight of explosive in a charge whose base diameter of the liner is unity. By combining equations ( 1) and ( 2), the following equation is derived: -W=C(P/K)' ( 4) It will be apparent that by, substituting in equations ( 1) and ( 3) the values W and d of 95 a given charge exemplary of a series of the same design, and'the value of IP obtained from test firings of such a charge, the values of the constants C and K for that design may be determined When these values of C and K are 100 substituted in equation ( 4) above, one may deternine-either the penetration which may be expected from a charge of the same design having a weight of explosive W, or the weight of explosive W required to produce a desired 105penetration. -By the use of -the foregoing equations in conjunction with test data from a few types of special- purpose charges of varying designs, it is thus possible to select the proper design 110 for a particular purpose and to calculate the actual charge dimensi 6 ot for a particular size of the selicvd Zesign The determination of the proper amount of

'explosive required to produce a desired target hole size with a 115 selected design -and charge size, if hole size should be a major consideration, can be accomplished by a few simple experiments which involve merely varying the amount of explosive between liner and barrier while using 120 otherwise identical charge components The effect of such variance within the range of feasible hole sizes is minor From the foregoing detailed description of one embodiment of the invention and the 125 7; 8551 i 55 any objects in the vicinity The physical appearance of the barriers will, however, undergo certain specific and distinguishable changes, depending on which of the three aforementioned detonation front conditions is 70 produced. Thus, if conditions are such as to produce a high-order central detonation front and a high-order peripheral detonation front, 'the sharply defined annular zone of extremely 75 high pressure produced by the collision of these two high-order fronts forms a sharply defined circular cut or groove in the forward surface of the barrier close to the periphery thereof This definitely, identifies this con 80 dition. -f, howe-ver, conditions are suchi as to;,produce the preferred combination of a low-order central detonation front and a high-order peripheral detonation front, the distributed 85 zone of moderately higher pressure producedi by the merger of these two fronts forms a shallow depressioni of substantial width in the forward surface of the barrier, Because' of the relatively, lower velocity of the low-order 90 front, as compared to that of a high-order front, the region of initial meeting of the fronts in this instance 'is; at a shorter distance from the axis than in the case of the collision of high-order central and, peripheral Tironts 95 H Ience both the location and the form of the indentation or groove provide positive means of distinguishing between the two' above-mentioned, conditions'. Lastly, if conditions are such as to prevent 100 the development of a central detonation; front by shock pulsesp transmitted forwardly through the barrier, the extremely high, pressure developed' along the axis of the charge, by the converging of the peripheral front and' its 105 meeting at a point on the charge axis, produces a high velocity jet in 'both directions along the charge' axis The rearwardly 'directed jet blasts a large hole through' 'the -central portion of the barrier, "bht there is, no indica 110 tion on its forward surface of a collision or merging of detonation fronts, as in "the other two cases This conditioi-'can thus be identified,' It has' also been stated previously that 115 the' optimui' 'stand-off distance (from the base of the liner to the target) of shaped charges embodying the present invention' is substantially less than with charges heretofore developedl This is another resultof the differ i 20 ent mechanism ofd jet' formation According to the generally accepted theory of the

mechanism of jet formation in' a= conventional shaped' charge having single-point initiation of the nniiain charge, the liner is collapsed radially 125 inwardly 'upon' itself and the forward portion of 'the jet-'cbiotains liner' particles which are extnidied forwardly from the tcentre of thecollapsed liner hb the extremd inward collapsing' pressure This extrusion' of liner material 130 accompanying description of the newly devel oped, and proven theories of detonation and of jet formation in la shaped charge, it will be evident that by following these teachings a shaped charge having superior performance characteristics may be produced Furthermore, by the application of the principles set forth hereinabove to the design of shaped charges for various uses and purposes and to meet various conditions of use, it is possible to "itailor" a charge design for optimnumn perfonnance under a given set of conditions. For example, if a' large hole is 'desiredl, the charge may, be designed to provide a relatively large radius of curvature of the liner Application of ithe principles of this invention permits the concentration of a large portion of the material of the liner apex ini the forward, maximum-velocity portion of the jet. Thus the liner is, disposed at the proper distance from the barrier to cause the curvature of the central concave portion of the dt&onation front to substantially, conform to the curvature of the liner apex at the instant of impact of the detonation front on the liner apex Conversely, should 'a smaller hole size be desired, a smaller radius of curvature would be utilized, and' again in order to attain maximum efficiency the liner would' be disposed at a'distance from the barrier to ipermit conformation of the detonation front to the liner apex curvature, Reference has previously been made to the three distinctly different detonation front conditions produced at the forward' side of the barrier, depending on the type of explosive, the material and thickness of the barrier, and the thickness of the explosive behind the central portion of the barrier In addition to the criterion afforded' by the pronounced increase in target penetration; when conditions are such as to produce a low-order central detonation front andr a high-order peripheral detonation front, another and even more positive and reliable indication is available from:test' firing of charges from which it can be definitely determined which of the three detonation front conditions were produced This indication is afforded b 'an, examination of barriers after test firing of the charges. Inasmuch as the time interval, between detonation of the rearward layer 7 of explosive and detonation of the 'main explosive charge 4 is infinitesimally, small, of the order of one micro-second,, the forward velocity which would otherwise 'be imparted to the barrier 61 by detonation of the explosive layer 7 is counteracted and offset by the

rearward velocity imparted thereto by detonation of the main charge 4 Accordiugly upon firing the charge the barrier remains practically motionless and, in tests with charges having steel barriers the& barriers can be found in close proximity' to the original position of the charge, intact and' undamaged by impact on 78 15 j 155 v 1 occurs while the collapsed; liner is being propelled forwardly at a lower velocity than that of the extruded material, and it is believed'l-'to be for this reason -that a standf aptprximpately equal to the diameter of the charge must be provided in order to permit htis mechanism -to function properly. On the other hand, in a charge embodying the present invention a substantial portion of the liner at the apex end is projectedl forwardly along the axis at an, extremely high initial, velocity and, from the start of jet fornfation, forms the forward -portion of the jet. The effective stand-off in this instance might svell be measured f o mi a point near the apex of the liner rather than fromn its base Hence the stand-off -distance from the base of the Iiner to -,the target need be -merely a small fraction of 'that required for conventional charges This is obviously a distinct advantage in, uses of shaped charges which impose severe restrictions on the permissible over-all length of the charge plus the stand L-off distance. -Yet another important' characteristic of shaped charges embodying the present invent. tion, which is of particular advantage in certain iekds of use, is that the usual slug or carrot " may, if desired, be isubsnantiall Y eliminated, This is believed to be due;primiarily to the following factors: first, a large portion of the liner, starting at its apex end', is Projected into 'the -forward maximumivelocity portion of the jet and is disinte 6 grated during the process of penetration into the target; secondly) the enhanced' velocity g'radient along the jet assists in disintegration, of the intermediate and base portions of the& liner; and 'lastly,l because of the more 'efficient utilization of the available energy of the explosive 'by the higher average vel 6 city of the jet and the improved distribution of velocity 'along the jet, it is possible to use a liner of less wall thickiles' than is required for optimum performance of a conventional' shaped charge, resulting in a reduced amdunt of residual liner material to form a slug. While there has been illustrated and' described,lherein bu' m single embodiment of the present ilnventioi it will be apparent to thoseskilied,-in the art -that various -,iodificitions and changes mi the shape, material and-relative positions of the various components m 1 fay be made -withoutt -departing froni the essence of the invention

It is intended to cover herein all, such modifications and changes as come' within lthe true scope and spirit of the appended claims.

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* GB785156 (A)

Description: GB785156 (A) ? 1957-10-23

Automatic blowdown control mechanism for steam separator

Description of GB785156 (A)

PATENT SPECIFICATION Date of Application and filing Complete Specification: Nov 7, 1955. 785,l 56 No 31786155. Application made in United States of America on Nov 22, 1954. Complete Specification Published: Oct 23, 1957. Index at Acceptance:-Class 123 ( 2), A 42. International Classification:-F 22 b. COMPLETE SPECIFICATION Automatic Blowdown Control Mechanism for Steam Separator We, VAPOR HEATING CORPORATION, a corporation of the State of Delaware, United States of America, having its principal place of business at 80 East Jackson Boulevard, Chicago, Illinois, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to automatic blowdown control mechanism for steam separators associated with steam generators of the water tube coil type such as are usually employed to supply steam to the heating systems of Diesel powered passenger trains The steam separator units associated with such generators receive a mixture of steam and

hot water from the generator coils near the top of the unit and operate upon the gravity principle to separate the steam from the water The mineral constituents in the water are coagulated by the reaction of heat and water treatment chemical introduced therein and these minerals, in the form of sludge, are carried by the water into the separator The water and mineral sludge drop to the bottom of the separator while the steam is conducted to space heating devices which may be employed in the heating system To prevent undue accumulation of such sludge in the separator unit a -blowdown valve is provided at the bottom of the unit whereby the sludge accumulation may periodically be ejected from the separator to the atmosphere. Heretofore, where manual blowdown operations were resorted to, infrequent and irregular blowdowns resulted in undue waste of water as well as frequent clogging of the separators. In passenger train installations involving two or more locomotives, or dual locomotive units, effective blowdown operations necessitated the services of a trainman, usually a fireman, and required him to leave his station in the locomotive cab and walk through the various articulated units of the locomotive to effect lPrice 3 s 6 d l the necessary blowdown operations of the steam separator associated with the steam generator in such units In railroads encountering bad water conditloas, high water consumption and frequent clogging of the steam 5 Q separators have become factors that materially add to the cost of maintenance. The present invention is designed to overcome the above' noted limitations that are attendant upon manual blowdown operations 55 in passenger train operation and, towards this end, it contemplates the provision of a separator blowdown control mechanism which will operate automatically to blow down the steam separator of a steam generator, or to simul 60 taneously blow down the separator units of all steam generators employed in any particular train installation, at frequent predetermined intervals with each blowdown operation lasting a predetermined period of time 65 In carrying out these aims, briefly, the invention contemplates the provision of electrically operated control valves, one of which may be employed for operating an air cylinder associated with each blowdown valve of a 7,0 steam separator, together with a compacts unitary assemblage of electrical control mechanism, capable of being installed within a control box or on a control panel at a location remote from the steam generating plant, which 75 mechanism is timer controlled so that auto ' matic blowdown operations will take place according to a predetermined time schedule. The control mechanism further includes a main switch by means of which the apparatus may 80 be set for automatic operation or disabled at will and also includes push button means whereby, if desired, manual

control of blowdown operations may be effected so as to completely purge all separators of collected sludge 85 before the train enters a station and immediately after the train leaves the station. The provision of a blowdown control apparatus of the character briefly outlined above being among the principal objects -of the in 9 vention, other objects and advantages will appear as-the following description ensues. -A preferred embodiment of the invention is shown in the accompanying drawings, wherein: f Fig 1 is a side elevational view, somewhat schematic in its representation, showing a pair of Diesel locomotive units operatively connected together and each having associated therewith steam generating equipment to which the improved blowdown control mechanism of the present invention has been applied. Fig 2 is a schematic view of the electropneumatic control mechanism showing thesame partly in perspective and partly in section as being applied to a blowdown valve associated with a steam separator Fig 3 is an elevational view of a steam generator having a steam separator associated therewith and showing the control mechanism of the present invention applied thereto. Fig 4 is a plan view of a control panel on which certain of the present control equipment is mounted. Fig 5 is an enlarged sectional view taken substantially along the line 5-5 of Fig 2; and Fig 6 is a sectional view taken substantially along the line 6-6 of Fig -5. Referring now to the drawings in detail, in Fig 1 -there is illustrated a pair of Diesel locomotive units operatively connected to a train of passenger cars The leading and trailing Diesel-units 10 and -11 respectively each include in-addition to its Diesel power plant, a steam generator 12 of the coiled water tube type S such -as has been illustrated in more detail -in Fig -3, and each generator 12 is operatively connected to a steam separator 13 having a blowdown valve 14 and with which valves the control mechanism of the present inventionf is operatively associated As shown in Figs 1 and 4, certain portions of this control mrechanism are operatively mounted on a conitrol panel 15 suitably located in the cab of the Diesel unit 10 at a region which is accessible to the engineer, fireman or other trainman. Each of the steam generators 12 may be of a conventional type such as are' ordinarily employed to supply steam for heating railway passenger trains and includes among other things -the usual base 20 on which there is supported' a cylindrical section 22 in which the steam coils are: suitably arranged and an :upper section 24 providing a combustion-chamber for a liquid or gaseous fuel employed for firing

the generator The ignition and burner structure is'designated collectively at 25 and the outlet delivery valves 26 from the generator -are shown as being connected by means of a conduit 27 to a region near the upper end of the steam separator 13 The steam separator is also of conventional design and is in the form. of an elongated closed cylinder or tank 28 at the'top of which there is mounted the usual lead-off valve 30 by means of which steam that has been separated from its mineral constituents is sent through a pipe line to the heat exchangers or other devices (not shown) associated with the passenger car heating system The 70 lower end of the steam separator cylinder 28 is provided with a central threaded opening 31 (Fig 2) in which there is threadedly received the tail piece 32 of the blowdown valve assembly 14 75 The valve assembly 14 further includes a valve body 33 having an inlet passage 34 in communication with a passage 35 in the tail piece 32 and connected to the latter by a union ring 36 The valve body also has an outlet 80 passage 37 for sludge in communication with a nipple 38 which is held in position by a union ring 39 The tail piece 31 is provided with a valve seat 40 which cooperates with a valve element 41 carried at the upper end of a valve 85 stem 42 which passes through a gland 43 and the stem 42 is spring pressed as at 44 to normally maintain the valve element 41 seated on the tail piece seat 40. As shown best in Figs 5 and 6, the valve 90 element 41 is adapted to be lifted -from its seat by depression of a foot pedal 45 pivoted as at 46 on a rocker arm or lever 47 which in turn is pivoted as at 48 to an angular bracket 49 (Fig 5) secured by studs 50 to the valve body 95 331 A pair of springs 51 ' serve to maintain the pedal 45 in its elevated position The lever 47 has one end thereof disposed below and in engagement with the lower projecting end of the valve stem 42 and thus it will be seen that 100 upon depression of the foot pedal 45 and consequent clockwise movement of the lever 47 as viewed in Fig 6, the valve stem 42 will be moved upwardly to lift the valve element 41 from its seat to effect the blowdown operation 105 In order that the operator may effect a prolonged blowdown operation without having to maintain foot pressure on the pedal 45, a locking pin 52 extends upwardly from the body of the pedal and is designed for locking engage 110 ment with an abutment 53 formed on the bracket 49 By forward tilting of the pedal 45 after depression thereof, the operator may align the' end of the locking pin 52 with the abutment 53 (Fig 5) to hold the valve 41 open 115 Release of the locking pin may be effected by a reverse operation of the pedal 45. The blowdown valve 14 per se when operated by a foot pedal 45 is conventional structure The novelty of the present invention 120 resides rather in the novel construction, combination and arrangement

of parts about to be described in detail whereby the blowdown operations may be automatically performed -at spaced' intervals 125 Referring N ow to Fig 2, an air cylinder assembly 60 is provided for each of the blowdown valves 14 and is adapted to be secured to one flange of the angular bracket 49 by mounting screws 51 Each air cylinder in 130 785,156 2,93 permits manual blowdown operations at any desired time irrespective to the positions of the cam operated switches 91 and 92: ' It has been -found that in normal train operation it is desirable to -effect blowdown 70 operations for a fixed time period at predetermined intervals of time The, particular time period of the blowdowrf or the intervals between such operations may vary, depending upon the quantity of sludge forming minerals 75 contained in the water in the region through which the train is operated: Where pedal operated separator blowdowns are concerned it has been the practice of the trainman to appear at each blowdown station periodically and depress 80 the foot pedal 45, so as to open the blowdown valve 41 for such period as the trainman deemed proper to clear, the sludge from -the separator Before -entering a station and immediately after leaving the same, it has been 85 the custom to effect a longer blowdown impulse, utilizing the lock pin 51 and abutment 53 as previously described The timer mechanism 90 -of the present invention is designed to simulate these desired blowdown 90 impulses with rhythmic accuracy and in an unfailing manner but with an accelerated frequency which is impractical where manual operations are concerned. Accordingly, as shown in Fig 2, the cam 95 switch 92-is adapted to be closed by the timer mechanism at predetermined intervals, for example five minutes, and to remain closed for a shorter period, -for example seconds during each five minute interval During said five 100 minute period the cam -switch 91 is closed a number of times, for example once each twenty-seconds, and remains closed for at least one second Consequently an energizing circuit to the solenoid 85 of the air valve structure 74 105 is completed once during the time that the cam switch 92 is closed: To effect the above described blowdown operations, closure of-the, master switch S will establish a circuit through the timer motor M, 110 the circuit extending from-a suitable source -of current B, which -may be a battery, through lead 94, switch S, leads 95, 96, motor-M, and leads 97, 98, back to the source Energization of the motor M serves to drive a timer cam 99 -1-15 through a first gear reduction train 100 and the cam 99 is formed with a peripheral notch 101 which-cooperate with a cam follower 102 to permit periodic closing-movements of the cam switch 91 for the duration of one second 120 during, each twenty second, interval of time.

The timer cam 99 is -connected to a -second -tinier cam 103 through a second gear reduction train 104 The cam 103 is formed with a peripheral notch 105 which cooperates with a 125 cam follower 106 to permit periodic closing of the cam switch 92 for the duration of twenty seconds during each five minute interval. After initial closure of the switch S the system will continue to operate indefinitely 130 cludes a casing 62 providing a cylinder 63 therein in which there is slidable a piston 64 carried on a plunger 65 which projects -downwardly from the casing and carries at its lower exposedc end an adjusting stud 66 by means of which the effective stroke of the plunger may be varied within small limits The stud 66 is designed -for engagement with one end of a rocker arm 67 which is pivoted as at 68 to one arm 69 of the angle bracket 49 secured to valve 14 The other end of the rocker arm 67 carries an adjusting stud and lock nut assembly which underlies the operative end of the lever 47 associated with the foot -pedal 45 and which is designed for engagement therewith. The cylinder 63 is bled to atmosphere as at 71 below the piston 64 and above the piston it is connected through a conduit 72 to the outlet port 73 of a solenoid actuated valve assembly 74 operable upon energization thereof to admit air -under pressure to the cylinder 63 through the conduit 72 to drive the piston 64 downwardly in the cylinder 63 and thus cause counter-clockwise movement of the rocket arm 67 to elevate the valve stem 42 and lift the valve element 41 from its seat to effect a blowdown operation. The valve assembly 74 includes a casing 75 provided with an air inlet port -76 and a bleeder port 77, the port 76 being connected through a conduit 78 to a suitable source of air under pressure (not shown) The ports 76 and 77 communicate through a common passage 80 with the outlet port 73 and a pair of internal valve seats 81 and 82 at the ends of the passage cooperate with a dual valve and -stem element 83 to selectively-maintain the valve seats 81 and 82 open or closed in a mantier that will be described presently The valve element 83 is operatively connected to the movable core 84 of a solenoid assembly having a winding 85 operable upon energization thereof to move the valve element 83 downwardly within the casing to establish communication between the air conduit 78 and conduit 72 through the ports 76 and 73 to effect the blowdown operation as previously described Upon deenergization -of the winding 85 the -valve element 83 is restored to its normal position under the influence of a spring 86 to establish communication between the ports 73 and 77 and bleed the cylinder 63 to atmosphere above the piston 64 and thus terminate the blowdown operation. The electrical control instrumentalities whereby the magnet winding 85

of each solenoid valve 74 employed -in any particularinstallation may be periodically energizedinclude a timer mechanism 90, schematically shown in Fig 2 and which is conveniently mounted on the control panel 15 (Figs 1 and 4) This timer mechanism 90 operates to control the opening and closing movements of two cam operated switches 91 and 92 and arranged in series in the electrical circuit for the solenoid valve winding 85 A push button 785,156 and the cam switch 91 will become closed for the brief interval of one second at the end of each twenty second interval Such closure of the cam switch 91 will be ineffective to energize the magnet winding 85 until such time as the cam switch 92 becomes closed at the end of each five minute interval At such times as both switches 91 and 92 are closed a circuit will exist extending from the source B through lead 94, switch S, leads 95, switch 91, lead 107, switch 92 -and leads 108, 109, magnet winding 85, and leads 110 and 98 to the source Energization of-the winding 85 win, of course, effect the blowdown operation for the duration of such energization, as previously described. From the above description it will be seen that the timer cam 103 serves to establish a twenty second period of time at the end of each five minute interval during which the switch 92 become and remain closed so that during this period the separator 28 is potentially capable of blowdown operation subject to the intermittent opening and closing of the switch 92 under the control of the timer cam 99. During the remainder of the five minute interval when the switch 92 is open, the periodic intermittent closure of the switch 91 is without effect. If at any time it is desired to effect manual blowdown of the separator 13, the push button contacts 111 may be manually closed and such closure thereof will establish a circuit through the solenoid valve winding 85 extending from the source through the contacts 1, leads 112, 109, winding 85 and leads 110 and 98 to the source It is to be noted that this circuit is capable of being established at any time whether the switch S is open or closed The push button contacts 111 are, designed to permit manual blowdown of the separator immediately prior to entry of the locomotive into a station After such blowdown operation, the operator should open the master switch S and leave the same open until after the locomotive has left the yard or station to disable the automatic operation of the control mechanism inasmuch as it is undesirable to blow down the separators while the locomotive is in a station due to possible injury to train personnel or passengers. A terminal block 113 is mounted on the panel and makes provision whereby the solenoid valves 74 of the various separators of the train assembly may be connected in electrical parallel for simultaneous operation by the timer control mechanism 90 55

* Sitemap * Accessibility * Legal notice * Terms of use * Last updated: 08.04.2015 * Worldwide Database * 5.8.23.4; 93p

* GB785157 (A)

Description: GB785157 (A) ? 1957-10-23

Ion exchange resins and method of preparation thereof

Description of GB785157 (A)

I 1-11 iRa ' of 1711 'i - -y i:: f Tt \ 'Ice,; PATENT SPECIFICATION PATENT SPECIFICATION Inventor: IRVING MELVIN ABRAMS 785 W 157 Date of Application and filing Complete Specification: Nov 8,1955 No 31865/55. Complete Specification Published: Oct 23, 1957. Index at acceptance:-Class 2 ( 6), P 4 A, P 4 D( 2: 3 A), P 4 (F 1: K 7), P 4 P 1 E( 1: 5: 6), P 4 P( 2 A 1: 5: 6 D), P 4 T 2 (D:E:F:X), P 7 A, P 7 D 1 X, P 7 D 2 A( 1: 2 A: 2 B: 3), P 7 (D 3: FI: K 7), P 7 PIA, P 7 P 1 E( 1: 2:3:4:5:6), P 7 P( 2 A 1: 5: 6 D: 6 G: 6 X), P 7 T 2 (D: E:F:X), P 9 A, P 9 D( 1 BI:33), P 9 (F 1:K 7), P 9 PIE( 1:5:6), P 9 P( 2 A 1:5: 6 D), P 9 T 2 (D: E: F: X), P 11 A, P 11 D(l A: 7), P'l(F 1: K 7), P 11 PIE(l: 5: 6), Pl IP( 2 A 1: 5: 6 D), P 11 T 2 (D: E: F: X). International Classification:-CO 8 f. COMPLETE SPECIFICATION Ion Exchange Resins and method of preparation thereof We, CHEMICAL

PROCESS COMPANY, a corporation organized and existing under the laws of the State of Nevada, United States of America, of 58 Sutter Street, San Francisco, State of California, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention relates to ion exchange resins having functional ion exchange groups attached to conditioned, cross-linked resin matrices of copolymerized monovinyl aromatic monomers and polyvinyl monomers; and more particularly to the preparation of such resins by pre-polymerizing the monovinyl monomer in the presence of an inert gas to provide resin matrices for synthetic ion exchange resins having markedly advantageous characteristics The term " resin matrix " or "resin matrices" as employed herein designates the hard, infusible and water insoluble carrier resin or resins to which the functional exchange groups of ion exchange resins are attached. Ion exchange resins having functional ion exchange groups attached to resin matrices comprising cross-linked resinous copolymers of monovinyl aromatic monomers and polyvinyl compounds, and the preparation of such ion exchange resins are well known In manufacturing such copolymers from monovinyl aromatic and polyvinyl compounds on a commercial scale to produce ion exchange resin matrices, it has generally been found convenient and economical to mix the monovinyl monomer and polyvinyl monomer together with a suitable catalyst to form a homogeneous phase, and then to disperse such mixture with agitation in an aqueous medium containing a suitable suspending agent The resulting heterogeneous dispersion is heated until the liquid mixture of monovinyl monomers and polyvinyl monomers has been copolymerized to form hard, insoluble and infusible beads or granules The cross-linked copolymers thus formed have been employed as resin matrices for many types of cation and anion exchange resins For example, it is known to prepare a cation exchange resin from such a copolymer by sulfonation of the resin matrix, and an anion exchange resin in which the resin matrix is a copolymer of a monovinyl and polyvinyl compound. Although the resin matrices prepared from monovinyl and polyvinyl monomers in accordance with usual methods of preparation have been extensively employed in the manufacture of ion exchange resins, the properties of such resins are not all that are to be desired in an ideal resin matrix for ion exchange resins In the first place, the resins are not very porous. Therefore, large molecules such as color molecules are removed only to a limited extent by anion exchange resins prepared in a conventional manner, and no appreciable removal of color molecules occurs with

conventional cation exchange resins It is known that the porosity of such resin matrices may be increased by decreasing the amount of the polyvinyl compound employed in preparation of the resin matrix However, this also results in an ion exchange resin that swells considerably when immersed in water with a resultant decrease in exchange capacity of the resin on a volume basis. Also, when a resin matrix is prepared in the customary manner, it is difficult to avoid production of a high percentage of relatively small fine resin particles Such small particles are not suitable for use in upfiow ion exchange operations since they are either swept out of the column or cause plugging of a screen designed to prevent escape of the resin particles. Furthermore, such resins prepared without pre-polymerizing the monovinyl monomer exhibit greater volume change than is to be desired when they are subjected to solutions of varying ionic strength, and the resultant expansion and contraction cause a strain on the resin structure In addition, difficulties are encountered in making a sulfonated cation exchange resin in bead form without cracking or breaking of the spherical bead particles both during sulfonation of the resin matrix and during hydration of the sulfonated resin. Summarizing this invention, the foregoing problems are overcome and an ion exchange resin having markedly superior characteristics is produced by first polymerizing the monovinyl monomer separately, -such polymerization herein referred to as pre-polymerization, desirably subjecting the monovinyl monomer to an inert gas during such pre-polymerization so that the pre-polymerization is effected in an atmosphere of such gas, mixing the prepolymerized monovinyl compound with an unpolymerized polyvinyl compound, copolymerizing the mixture in the usual manner to form a cross-linked resin matrix, and then effecting reaction of functional ion exchange groups with said resin matrix by any of the well known procedures employed for this purpose to attach said groups onto said resin matrix The degree of pre-polymerization of the monovinyl monomer may be very slight, or the monovinyl monomer may be polymerized to a fairly viscous liquid without obtaining appreciable variation in the characteristics of the resin matrix of this invention. An ion exchange resin with the desired characteristics of the resin obtained by the method of this invention can be prepared only by pre-polymerization of the monovinyl component of the copolymer, and not by prepolymerization of the polyvinyl compound. Polymerization of the polyvinyl compound or a mixture of the polyvinyl compound and monovinyl compound proceeds too rapidly to be controlled Even with use of conventional inhibitors, the pre-polymerization of the polyvinyl monomer with subsequent copolymerization of a mixture of

polyvinyl compound and monovinyl monomer can not be utilized to produce the resin matrix of this invention. The properties of the resultant ion exchange resins prepared by pre-polymerizing the monovinyl compound are different in many respects from the properties of resins prepared without such pre-polymerization by conventional means The resins of this invention are relatively -opaque compared to the translucent ion exchange resins of identical constituents prepared without first pre-polymerizing the monovinyl compound It is believed that the relative opaqueness is due t Q the presence of pores larger than the wave length of light in the resins of this invention and the translucence of conventional ion exchange resins due to pores smaller than the wave length of light. Furthermore, the ion exchange resin 70 matrices prepared by pre-polymerization of the monovinyl compounds are of uniform composition throughout while the resin matrices composed of cross-linked copolymers of monovinyl and polyvinyl monomers prepared in 75 the conventional manner without such prepolymerization are surrounded by a hard surface layer This is evidenced by the slow rate of sulfonation of the outer surface of conventional ion exchange resin matrices in the pre 80 paration of sulfonic acid cation exchange resins unless a swelling solvent is used, and the comparatively rapid sulfonation of the interior of such conventional resin matrices once the reaction has been commenced On the other hand, 85 sulfonation of the ion exchange resin matrices of this invention occurs at a uniform rate. Also, upon compression of a spherical particle of a conventional ion exchange resin matrix until breakage occurs, the resin acts like a 90 body having a thin rigid skin surrounding it. However, the resin matrix of this invention on compression acts as if it has a homogeneous structure In addition, the slow rate of diffusion at the outer surface of conventional ion ex 95 change resins is probably caused by the presence of an outer shell having a higher degree of cross-linking than the interior of the resin. The greater porosity of resin matrices in 100 which the monovinyl monomer was pre-polymerized before copolymerization enables anion exchange resins prepared therefrom to remove an appreciably greater amount of color, and to have a higher -capacity for removal of color 105 than corresponding anion exchange resins prepared by conventional methods Also, the porous cation exchange resins prepared from such resin matrices remove color from color bearing solutions, whereas conventional poly 110 styrene type cation exchange resins do not generally remove appreciable quantities of color because the available surface area is restricted. Another advantage resulting from pre 115 polymerizing the monovinyl

monomer is that in the preparation of the resin in bead form, larger beads may be made by increasing the extent of the pre-polymerization Such large beads are often desirable for use in columnar 120 upflow operations where the loss of small beads through the system would create a problem Furthermore, variations in the particle size of the ion exchange resin made from the matrix of this invention when subjected to 125 solutions of varying ionic strength are somewhat smaller than conventional beads, thereby providing a structure which is subjected to less strain Also, the resin matrix prepared by prepolymerizing the monovinyl monomer may be 130 7; 85,157 785,157 3 both sulfonated and then directly hydrated without breakage, whereas a high percentage of the resin beads prepared in accordance with standard practice without pre-polymerization of the monovinyl monomer crack and break upon sulfonation, and most of the remaining beads break and shatter upon immersion of the sulfonated resin in water This is of considerable importance in the preparation of satisfactory sulfonated type cation exchange resin. The accompanying drawing is a graph illustrating the percent color removal of an anion exchange resin prepared from the resin matrix of this invention compared to the percent color removal of an anion exchange resin of the same components and in the same percentages prepared in accordance with the conventional manner, the preparation of such resins being described in Example 4 hereof. Although pre-polymerization of the monovinyl compound either with or without conducting the pre-polymerization in an atmosphere of inert gas so as to exclude air produces the desirable results heretofore described and results in an ion exchange resin with substantially the same color removal properties, surprising improvements in the method and resultant ion exchange resin are obtained by conducting the pre-polymerization in the presence of an inert gas The time required for pre-polymerization to a desired viscosity in the presence of an inert gas is much less than the time usually required when the monovinyl monomer is in contact with oxygen of the air Furthermore, when the prepolymerization is conducted in the presence of an inert gas, the time for pre-polymerization is relatively constant for a particular monovinyl monomer, whereas in the presence of air the pre-polymerization time varies considerably. As a result, the use of an inert gas in the prepolymerization step is very advantageous for the commercial production of ion exchange resins since it eliminates the necessity of constantly checking the progress of the prepolymerization, and this materially enhances obtaining uniform quality of the final product. The amount of inert gas employed is inmaterial as long as it is sufficient to exiclude air.

Also, other surprising advantages are obtained by the use of an inert atmosphere in pre-polymerization of the monovinyl compound The physical structure of the resin matrix prepared in accordance with this invention is effected even less upon subsequent sulfonation or amination for producing ion exchange resins than the excellent strong and improved resin matrix obtained by pre-polymerization in the presence of oxygen of the air Consequently, the resultant ion exchangeresin is particularly uniform and firm In addition, higher-and more consistent ion exchange capacities arei obtained with ion exchange resins prepared by pre-polymerization of the monovinyl monomer in the presence of an inert gas The use of an inert gas in accordance with this invention is advantageous only in the pre-polymerization of the monovinyl monomer No particular advantage is obtained by conducting the final copolymerization of the monovinyl compound and the polyvinyl compound in the presence of an inert gas. In greater detail, any monovinyl aromatic monomer with an unsubstituted vinyl group commonly employed in the preparation of the well known resin copolymers of monovinyl compounds is suitable for use in this invention 80 Examples of such monovinyl monomers are styrene, vinyl toluene, vinyl xylene, vinyl naphthalene, ethyl vinyl benzene, and vinyl chlorobenzene, as well as other monovinyl aromatic compounds with unsubstituted vinyl 85 groups When the monovinyl group contains another radical, particularly an organic radical such as a methyl radical, substituted for a hydrogen atom in the vinyl group, the polymerization does not proceed to the extent de 9 o sired for production of a resin matrix suitable for an ion exchange resin. The monovinyl monomer of the character described may be pre-polymerized to produce a somewhat viscous liquid The degree of poly 95 merization-is readily determined by viscosity measurements and it may be varied over a relatively wide range For example, the monovinyl monomer may be pre-polymerized to a viscosity of as low as 0 1 poise or as high as 100 poises or even higher without adversely affecting the characteristics of the resultant resin matrix Below 0 1 poise some of the advantageous characteristics resulting from prepolymerization of the monovinyl monomer are 105 lost, whereas above 30 poises the high viscosity of the liquid renders it difficult to disperse the mixture if suspension polymerization is to be employed, and the bead size becomes undesirably large and difficult to control Hence, pre 110 polymerization of the monovinyl monomer to between 0 1 and 30 poises provides a practical range if suspension polymerization is employed to make the beads It has been found most convenient in suspension polymerization 115 to pre-polymerize the monovinyl monomer to a viscosity of between 2 0 and 8 0 poises. Higher viscosities may be used if the beads are formed by extrusion of

droplets of the monomer and polymer mixture of predetermined 120 size. If the pre-polymerization is continued until the viscosity becomes undesirably high, the viscosity of the' pre-polymerized monovinyl compound can be reduced by adding the 125 monovinyl compound partially polymerized to a lower viscosity of by adding the unpolymerized monomer Similarly, if it is desired to increase the viscosity of a monovinyl compound that has only been pre-polymerized to a 130 785,157 low viscosity, more completely polymerized is employed for the pre-polymerization. monovinyl compound may be added When styrene is pre-polymerized by-the use In a modification, the pre-polymerized of heat alone while exposed to air at a temmonovinyl compound may be provided by dis perature of about 1000 C, the time for presolving a completely polymerized monovinyl polymerization to about 3 poises varied from 70 aromatic compound in a monovinyl monomer five hours to more than twenty-two hours. until the desired viscosity is obtained This However, when an inert gas is employed under method provides a final ion exchange resin similar conditions, the time for pre-polyhaving all of the advantages of the resin ob merization to the same viscosity was contained by pre-polymerizing a monomer sistently about four hours The shortened and 75 directly-to the viscosity to be employed Con more consistent time for pre-polymerization is sequently, commercially available monovinyl highly advantageous since it avoids the necesaromatic compounds that have been corm sity of constantly checking the degree of prepletely polymerized may be obtained and dis polymerization, and enables the production of solved in a monovinyl monomer to provide ion exchange resin matrices that are relatively 80 the pre-polymerized monovinyl compound em consistent in size and properties As previously ployed in accordance with this invention disclosed, the extent of the pre-polymerization Pre-polymerization of the monovinyl mono has an effect upon the size of the ion exchange mer is preferably carried out by subjecting the matrix beads produced upon suspension comonomer to heat while it is exposed to the polymerization, and with an inert gas the 85 inert gas The use 7 of elevated temperatures degree of pre-polymerization is easily rendered without a catalyst provides the best means of relatively constant In addition, the use of an controlling the degree of pre-polymerization, inert gas during pre-polymerization makes the since the presence of a catalyst makes it diffi resin matrix even stronger and more resistant cult to stop the pre-polymerization at the to rupture, and also provides ion exchange 90 desired viscosity Agitation of the monovinyl resins with higher and more consistent monomer while maintaining a temperature of capacities than the excellent resin matrix obbetween 80 WC and 1200 C is

preferred as the tained by pre-polymerization in the presence method of carrying out such pre-polymeriza of oxygen of the air. tion, but this temperature range is not critical Any inert gas that is unreactive with the 95 If the pre-polymerization-of -the monovinqylj monovinyl monomer and which is free of monomer is effected by a catalyst, any catalyst -available oxygen may be employed for the commonly used as a polymerization catalyst pre-polymerization Carbon dioxide and nitrofor such monomer may be employed, as long gen are-preferred since they are readily availas the reaction is kept under control For able Examples of other inert gases that might 100 example, the organic peroxides, such as ben be employed are helium, argon, methane and zoyl peroxide, lauroyl peroxide, tertiary-butyl ethane The introduction and use of an inert hydroperoxide, and methyl ethyl ketone gas in the pre-polymerization step may be peroxide may be used Also, "per" compounds accomplished by bubbling the gas into the such as tertiary-butyl perbenzoate are suitable monovinyl compound contained in a reaction 105 In addition, acid type catalysts such as vessel-of the usual type in which such reactions aluminumn chloride and sulfuric acid may be are conducted, namely, one having a relatively employed in the pre-polymerization of the narrow upper opening compared to the size of monovinyl monomer When a catalyst is em the vessel, such as any refiux condenser which ployed to accelerate the pre-polymerization, will permit entrapped air in the vessel to 110 the amount should be small since-too much escape as the inert gas is introduced In this catalyst in the pre-polymerization process manner, the inert gas sweeps out the air in the renders the degree of pre-polymerization diffi reaction vessel Also, as long as the inert gas cult to control and also results in a weaker is constantly entering the vessel through an and softer final resin matrix An amount of inlet conduit and escaping through the open 115 catalyst, if employed, between 0 1 to 1 0 per ing in the upper part of the vessel, it prevents cent by weight of the monovinyl monomer is entry of air The flow of inert gas into the preferred reaction vessel is preferably commenced before By conducting the pre-polymerization of the the pre-polymerization is started in order to monovinyl monomer while it is exposed to an remove air initially present in the reaction 120 inert gas, substantial advantages are obtained vessel, and it is continued until the pre-polyThe time required for pre-polymerization to a merization has been completed. desired viscosity is rendered relatively con Afterpre-polymerization of the monovinyl stant for a particular monomer under any compound to the desired extent, the introgiven conditions Also, the time for pre duction of the inert gas is preferably discon 125 polymerization is substantially reduced These tinued because when the desired state of

preadvantages are particularly desirable with the polymerization is reached, it makes no preferred method of pre-polymerization by difference whether the partially pre-polythe use of heat alone, although the use of an merized monovinyl compound has access to the inert gas is also advantageous when a catalyst air The partially pre-polymerized monovinyl 130 785,15 A 7 785,157 compound is then cooled to a temperature that will stop further polymerization, preferably to room temperature, and thoroughly intermixed with the polyvinyl monomer so that the mixture forms a homogeneous phase If desired, introduction of the inert gas can be continued during the cooling phase. Any polyvinyl compound may be used which will form a cross-linked insoluble, infusible copolymer when copolymerized with the monovinyl aromatic compound Polyvinyl compounds of such character are well known in the art Examples of such compounds are divinyl benzene, divinyl toluene, divinyl xylene, divinyl naphthalene, trivinyl benzene, divinyl chlorobenzene, diallyl phthalate, divinyl acetylene and diallyl fumarate The usual commercial mixtures containing divinyl benzene are preferred for use in providing the divinyl constituent because of their ready availability Mixtures of vinyl compounds containing from 20 % to 55 % of the polyvinyl constituent have been employed in producing satisfactory ion exchange resins in accordance with this invention. A conventional polymerization catalyst is preferably intermixed with the mixture of the pre-polymerized monovinyl compound and the polyvinyl compound in order to effect the final polymerization at a suitable rate Although the final polymerization could be carried out by use of heat alone, the process would take an undesirably long time to carry out, and the properties of the resin matrix would not be desirable for ion exchange purposes Polymerization catalysts that effect rapid polymerization of the mixture of pre-polymerized monovinyl compound and polyvinyl monomer are well known in the art Among the suitable catalysts for use in the practice of this invention are ozone, organic peroxides, inorganic peroxides and the "per" salts such as water soluble perborates, persulfates and perchlorates. The proportions of the monovinyl aromatic compound and the polyvinyl compound employed in the preparation of the resin matrix of this invention may vary considerably, and the resultant exchange resin produced therefrom may be used for ion exchange purposes regardless of such variations in portions However, the relative amounts of the monovinyl compound and polyvinyl compound employed govern properties such as hardness and complexity of the resin matrix, which properties in turn effect subsequent reactions of the resin matrix and also the properties of the final ion exchange resin.

Too small an amount of the polyvinyl compound results in a resin matrix that swells considerably and may partially dissolve in subsequent reaction media, and the final ion exchange resin may also swell excessively in the course of ion exchange reactions Furthermore, use of too small an amount of the polyvinyl compound provides an ion exchange resin of comparatively low density and as a result the exchange resin has a low capacity per unit volume On the other hand, too great a percentage of the polyvinyl compound provides a dense resin matrix that will react very slowly 70 in the subsequent steps of preparing the ion exchange resin Also, when a high proportion of the polyvinyl compound is employed, the resultant dense final exchange resin has a low rate of ion exchange and a low exchange capa 75 city A suitable range of proportions of the monovinyl aromatic monomer is from 60 0 % to 99 9 % -by weight with the corresponding range of the polyvinyl compound being from 40.0 % to 0 1 % The preferred range is from 80 85.0 % to 95 0 % by weight of the monovinyl monomer compound and 5 0 % to 15 0 % of. the divinyl compound Thus, the resultant copolymerized ion exchange resin matrix is formed from a major proportion of the mono 85 vinyl compound Approximately 0 1 % to 2.0 % of the catalyst is used in the final polymerization based upon the total weight of the compounds to be copolymerized. The final copolymerization of the pre-poly 90 merized monovinyl aromatic compound and the polyvinyl compound may be carried out by any of a variety of well known methods A mixture of pre-polymerized monovinyl compound, polyvinyl monomer and catalyst may 95 be polymerized in bulk or such a mixture may be suspended in a liquid medium and then polymerized The well known technique of suspension polymerization described in Chapter I, pages 1 to 20 of "High Molecular 100 Weight Organic Compounds", by Holenstein and Mark is preferred In this process a mixture of the liquid vinyl compounds and a soluble catalyst such as benzoyl peroxide, are suspended with continuous stirring in an 105 aqueous medium containing a hydrophilic suspending agent such as polyvinyl alcohol or gum arabic The application of heat to the suspension converts the compounds successively into viscous droplets, small rubbery 110 particles, and finally into hard-bead-like spheres Nearly all the spheres of the insoluble vinyl hydrocarbon copolymer pass a 16 mesh screen but are retained on a 60 mesh screen. If desired, larger beads may be prepared by 115 employing a slow rate of stirring, and also by pre-polymerization of the monovinyl aromatic compound to a highly viscous liquid When the mixture of pre-polymerized moliovinyl compound and polyvinyl compound is poly 120 merized in bulk, a resin matrix in bulk form is obtained rather than

bead form The bulk matrix has all of the advantages of the resin of this invention, such as greater porosity, but it does not have the desirable property of be 125 ing in bead form for convenient ion exchange operations. The resultant resin matrix is then employed in preparing any of the well known anion exchange resins or cation exchange resins in 130 which functional ion exchange groups are attached to a resin matrix copolymer of a monovinyl aromatic monomer and a polyvinyl monomer For example, the amnination of such S a resin matrix with nitric acid may-be accomplished in order to produce an anion exchange resin Strong quaternary ammonium type anion exchange resins may readily be prepared from the pre-polymerized ion exchange resin matrix by the methods now known in the art. Also, sulfonic acid cation exchange resins are readily produced by sulfonating such resin matrix with concentrated sulfuric acid, as described in Example 1 herein. Examples 1 to 3 are typical examples of the preparation of ion exchange resins in which the monovinyl monomer is pre-polymerizedin the presence of an inert gas. The resulting beads were white and relatively 65 opaque. Preparation of Cation Exchange Resin. Twenty grams of these beads were sulfonated using 100 cc of 94 5 % sulfuric acid at a temperature of 1000 C for 6 hours To maintain 70 the acid concentration, a total of 30 cc of 104 % sulfuric acid was added during the sulfonation The excess acid was drained off and the beads were immersed in 1 liter of tap water After thorough washing, the exchange 75 capacity was determined and found to be 2 2 equivalents per liter The beads were relatively opaque and light brown in color Practicallyall of the beads were perfect, uncracked spheres 80 As a control, a cation exchange resin was prepared in the same manner and with the same ingredients and proportions as specified Ex AMPLE 1 in the beginning of the Example except that Pre-Polymerization A 500 cc three-neck the pre-polymerization was conducted without 85 round bottom flask fitted with a stirrer, use of an inert gas A period of 17 hours was thermometer and gas inlet tube was employed required for pre-polymerization of the styrene in this Example The inlet tube was connected to a viscosity of about 2 8 poises at 25 'C. to a cylinder of carbon dioxide gas under The capacity of the final cation exchange resin pressure The flask was heated and swept out was 1 8 equivalents per liter 90 with carbon dioxide gas after which 300 cc of monomeric -styrene was added The temnpera-_ EXAMPLE 2. ture was maintained by a heating mantle at Pre-Polymerization 100 cc of commercial 1000 C for a total of 4 hours and 10 minutes styiene was polymerized by placing the after which the viscosity of the liquid was

styrene mixed with 0 28 grams of benzoyl found to be 2 8 poises at 25 C Carbon dioxide peroxide catalyst in a 500 cc three-neck round 95 gas was continuously introduced into the reac bottom flask fitted with a stirrer, thermometer tion flask to exclude outside air until the pre and gas inlet tube Carbon dioxide gas was polymerization -was complete; and then the bubbled into the styrene in the same manner introduction of the inert gas was discontinued as in Example 1, and the flask was heated (Gardner-Holt Method is used in this and all by a heating mantle set for 80 GC The reac 100 following viscosity measurements) tion was exothermic and difficult to control Copalymerization This pre-polymerized and the temperature reached 870 C at one styrene was allowed to cool to 300 C, and to point-even when the heating mantle was re75 cc of the cooled pre-polymerized styrene_ moved and the flask containing the styrene was added 25 cc of a 40 % solution-of corm was immersed in cool tap water A viscosity 105 mercial divinyl benzene containing 0 70 grams of 7 0 poises (at 250 C) was reached after 2 of benzoyl peroxide to make a total volume of hours, at which time the introduction of the about 100 cc The commercial polyvinyl mix inert gas was discontinued. ture contained 40 % divinyl benzene, 50 % Copolymerization In making up the coethylvinyl benzene and 10 % diethyl benzene polymerization mix, 74 3 cc of the pre-poly 110 The viscous solution of pre-polymerized merized styrene was added to 25 7 cc of a monovinyl compound, divinyl benzene and commercial solution containing 35 % divinylcatalyst was poured into a three-neck, 500 cc benzene to provide a total volume of 100 cc. flask containing 200 cc of a 1 % aqueous solu An additional 0 5 grams benzoyl peroxide was tion of soluble starch as a suspending agent added as a catalyst for the copolymerization 115 at a temperature of 85 WC The contents were The polymerization to the bead form of the agitated with a mechanical stirrer so as to resin matrix was completed in the manner result in a suspension of a liquid non-aqueous described in Example 1 phase in the aqueous solution The tempera Preparation of Cation Exchange Resin. ture was maintained at 85 C by means of a Twenty grams of the beads of resin matrix 120 heating mantle and variable transformer for were sulfonated and hydrated in the manner about two hours until the globules gelled to described in Example 1 for preparation of a form:hard beads with a density greater than 1 cation exchange resin The resulting beads water The -temperature was then raised to were light brown and relatively opaque as be C and held there for 12 hours The con fore There was very little splitting or break 125 tents of the flask was then cooled, the beads ing during sulfonation and hydration The were filtered off, washed with water, and dried beads -were

somewhat softer than the cation in a, circulating air oven at 9 W O C for 1 hour exchange resin of Example 1 prepared withI 785,157 6 volume and 10 centimeters high at the rate of bed volumes per hour The color removal was followed by periodic readings of the effluent with a Klett-Summerson calorimeter. Furthermore, it was observed that the adsorbed 70 color was more thoroughly removed from the pre-polymerized resin when the pre-polymerized resin and the control standard resin were regenerated with alkali. EXAMPLE 4 75 Pre-Polymerizationt 150 cc of a commercial grade vinyl toluene (about 70 % meta-methyl styrene and 30 % ortho-methyl styrene) was heated in a 250 cc Erlenmeyer flask fitted with a cork stopper and thermometer exposed 80 to the atmosphere without use of an inert gas. The liquid was kept at 100 CG for 7 hours, then cooled to room temperature The viscosity was found to be 3 2 poises at 25 GC. Copolymerization A copolymerization mix 85 was then made up using 87 cc of this prepolymerized vinyl toluene, 13 0 cc of a commercial solution of divinyl benzene containing 53.9 % divinyl benzene and 0 545 grams of benzoyl peroxide A suspension polymerization 90 was carried out in which this solution was suspended in 250 cc of an aqueous solution containing 0 5 % polyvinyl alcohol The temperature was held at 85-880 G for 5 hours, then raised and held at 90 CG for 20 hours 95 The resulting beads were cooled, washed with water, and dried in a hot air oven at 95 GC. for 5 hours. Preparation of Anion Exchange Resin. Twenty grams of dried beads were swelled 100 in 250 cc of benzene in a 3-neck 500 cc. balloon flask at 60 CG for one hour with agitation With the beads fully swollen, 13 cc. of phosphorus trichloride was added and gaseous chlorine was bubbled into the reaction 105 flask at the rate of 3 to 4 bubbles per second. The temperature was maintained at 68-70 GC. for 20 hours, after which the contents of the flask was cooled, the beads were washed thoroughly with benzene, then methanol, then 110 benzene again. Without drying, the resin was immersed in cc of benzene in a 500 cc balloon flask fitted with a mechanical stirrer, thermometer and stopper Fifty cc of dimethylethanolamine 115 was added and the temperature was raised to 'C and maintained for 3 hours The resultant aminated beads were washed thoroughly with methanol, then water The resin was placed in a 1 inch glass tube and 120 cycled twice with 3 N 11 C 1 and 2 N Na OH.

The salt-splitting capacity was found to be 0.63 equivalents per liter The resulting product was opaque and a light cream color when in the salt form, and brown in the hydroxide 125 regenerated form. Preparation of Anion Exchanger by Standard Procedure The ingredients, proportions and procedure of copolymerization, chlorination and amination was exactly the same as in the 130 out use of a catalyst in the pre-polymerization. The exchange capacity was 1 7 equivalents per liter. EXAMPLE 3. Pre-Polymerization 100 cc -of monomeric styrene was pre-polymerized by heating in a 500 cc three-neck round bottom flask at about 1050 C for 3 hours and 15 minutes with nitrogen gas being continually introduced through J the gas inlet tube during pre-polymerization as in Example 1 The resulting viscosity was 2.4 poises at 25 CG. Copolymerization 85 cc of the pre-polymerized styrene was mixed with 15 cc of a 40 % commercial divinyl benzene solution containing 0 6 grams of dissolved benzoyl peroxide to make a total volume of about 100 cc The suspension polymerization was carried out in the manner described in Example 1. Preparation of Anion Exchange Resin. Twenty grams of the dried beads of resin matrix was immersed in 100 cc of methyl chloromethyl ether (boiling range 58-610 C) The beads were allowed to swell at room temperature with agitation for 2 hours 34 grams of powdered anhydrous zinc chloride was added, and the temperature maintained between 20 CG and 30 'G for 3 hours The product was washed first with isopropanol, then with water and finally dried overnight in an oven at 800 G 20 grams of the dried, chloromethylated beads were swelled in 80 cc benzene, after which 80 cc dimethyl ethanolamine was added and the reaction mixture was allowed to reflux for 3 hours The resulting product was washed with benzene, then with methanol, and finally with water The final beads were spherical, relatively opaque and had a yellowish tinge The salt-splitting capacity of this resin was found to be 0 90 equivalents per liter. To test the comparative adsorptive properties of this resin, a colored commercial sugar solution obtained from a beet sugar factory was run through a column of resin prepared as described above in parallel with the same volume of a control resin prepared in a similar manner, using styrene monomer which was not pre-polymerized In both cases the resins were in the hydroxyl form, having been regenerated with an excess of sodium hydroxide. The colored sugar solution was passed first through a conventional cation exchanger and then divided into two portions One portion was passed through a bed of anion exchanger prepared by the pre-polymerization procedure of this example, and the other through

the same volume of a bed of the control resin, both to p H breakthrough Color removal in the pre-polymerized sample was about 50 % whereas in the control sample it was only about %, the measurements being made by passing a divided flow of filtered and diluted colored molasses solution through columns of the respective ion exchange resins 60 cc in 785,157 preceding portion of this Example, except that the methyl styrene monomer was used instead of the pre-polymerized syrup The saltsplitting capacity of this resin was found to be 0 68 equivalents per liter The final product had a translucent appearance and was yellow in the salt form and a dark orange in the hydroxide-regenerated form. The adsorptive properties of the anion exchange resins prepared in this Example by the pre-polymerization technique of this invention were compared with a similar anion exchange resin prepared by standard procedure by the following procedure A solution of _Hydrol", the highly colored molasses of the corn sugar industry, was, diluted ten-fold, clarified by filtration with diatomaceous earth, then passed through a column of conventional cation exchanger in the acid form The -"Hydrol" solution was then finally divided, and the respective divided portions were passed through columns containing equal volumes of the two anion exchangers of this Example, in the hydroxide-regenerated form. Each column of anion exchanger was 60 cc. in volume and 10 cm high The rate of flow in these columns -was 10 bed-volumes per hour The results were followed by periodic readings of the effluent with a KlettSummerson jcolorimeter The graph illustrates the different behavior of the two resins The percentage color removal was obtained by the following formula: Cm %C.R =( 1) 100 Ci: = i where C, is the colorimeter reading of the effluent and C is the reading of the influent. On completion of the color removal test, the resins were again regenerated with an excess of 2 N sodium hydroxide whereby the adsorbed color was readily removed and the original colors of the resins were restored.

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