NOVEMBER, 1933 ISDUSTRIAL AND ESGINEERING CHEMISTRY 1303

tank, penetration still continues for a time because of further contraction of the air in the interior of the lumber. Apparent rapid drying of stock thus processed is due rather to this pro- gressive penetration than to rapid volatilization of solvent from the surface.

With 35 gallons per 1000 feet absorption of Bruce Preserva- tive, there is approximately twenty times as much toxic prin- ciple in the lumber as is required to inhibit fungus and termite attack. The penetration secured is beyond any probable depth of checking. The lumber has been sterilized completely during the heating process. In commercial treatment 20 to 30 gallons of preservative per 1000 feet is common practice. The sapwood usually absorbs the preservative more readily than the heartnrood, which is fortunate since sapwood is most

commonly used and needs the protection to a rnuch greater extent.

The impregnation process used and the superior penetrat- ing power of the preservative itself permit ample protection to be obtained by the Bruce process without the necessity of using the high pressures required to accomplish sufficient pene- tration in many of the older processes.

Another interesting feature of this process is that the pre- served lumber is ready for use immediately after treatment. Lumber delivered to the treating plant in the morning can be delivered to the contractor the same day. This feature allows the architect to specify any kind of construction without danger of long and costly delay. RECEIVED April 27, 1935.

Courtesy, A merican-LaFrance and Foarnzte I n d u s t r i e s , Inc.

FOI~TY-GALLON FOAMITE ENGINE BEING ~ J S E I I ON 4N INFL43lMABLE LIQUID FIRE

ORIPARATITELT little published in- formation can be found on the subject of fire and explosion hazards of the chemical

industries. Reports of inveFtigations of government bureaus. fire insurance companies, the Cnderwriters’ Laboratories, and inspection and fire insurance rating bureaus are available upon request. These, however, do not corer the entire sub- ject, nor is their availability well known in the industry.

Although the chemical industry is still young and pri- marily interested in developing new processes and products, the importance of prevention of fire and explosion cannot be overemphasized. The chemical industry deals with hazardous materials. Nearly all organic compounds are combustible. Many of them are highly inflammable or explosive, and Some

0 0 0

Fire Prevention

and Protection

in Chemical Industries

BERNARD F. FLOOD R o p l Li>erpool Groups, Columbus, Ohio

are auhject to spontaneous ignition, e.specially when storetl under certain conditions or in contact with certain other materials. Inorganic compounds are generally considered noncombustible but there are exceptions, such as oxidizing agents or explobives, x-hich are quite hazardous. Xot only are the handling and storing of these compounds hazardous, but there are also hazards encountered in processing them 77-hich are distinct from the hazards of either the raw materials or the finished products. I t is not intended to set forth all the hazards of chemical processes in this article but rather to describe some of the methods of controlling arid preventing weeping fires in chemical plants by proper construction and protection of the buildings which house the industry.

When a new chemical plant is to be designed or an old plant remodeled, the following general points are important:

1. Construction should be as nearly fireproof as feasible. 2. The hazardous processes should be isolated within separate

3. All specially hazardous processes should be properly

4. -411 hazardous conditions not’ inherent to the process should

5 . Ample fire-fighting equipment should be provided.

Construction

The word “fireproof” is a misnomer. Records show many instances of so-called fireproof buildings that have been seri- ously damaged or destroyed by fire. However, a building is

fire areas.

safeguarded.

be eliminated or safeguarded.

NOVEMBER, 1935 INDUSTRIAL AND ENGINEERING CHEMISTRY 1307

masonry fire wall on the side of the building housing the ex- plosive operation toward the balance of the plant. The roof and the side away from the plant may be made of light con- struction fastened lightly to the more substantial part of the building.

Special Hazards The proper safeguarding of specially hazardous processes

is a matter of common sense. Some processes and materials which have become rather common in the industry today have been studied by fire prevention engineers and standards set up for their proper protection. Pamphlets are available on numerous subjects, including the use of combustible an- esthetics, w e of artificial coloring of fruits and vegetables, storage and use of nitrocellulose film and similar products, spraying and dipping hazards, and many others involving chemical and physical processes in industry. Besides separat- ing especially hazardous processes from the balance of the plant, such processes as nitration, sublimation, distillation, grinding, and, in general, all processing of organic materials where temperature and pressure control is essential or where inflammable vapors or dust are generated, require close super- vision.

The requirements of proper ventilation must be studied carefully. The explosive range of most vapors is now avail- able in the literature and should be considered in determining the natural or artificial ventilation necessary for a room or building housing vapor hazards. Recent investigations of the hazards of dust explosion should be consulted. Sight glasses and fragile attachments on stills, tanks, and other equipment should be eliminated or safeguarded fr'oni mechani- cal injury. Antisiphon and aritiflooding devices afford a means of safety where pumps handling hazardous liquids take suction under head or from tanks at a higher level.

The use of nonsparking tools and even the regulation of the clothes and shoes of the workmen must often be a part of the program. The electrical grounding of all equipment, proper venting to the outside, and use of screen5 on these vents, as well as on windows and doors, must be consid- ered.

Courtesy, Pyrene Manufacturing Company

FOAM INSTALLATION PIPED TO SEVERAL FIRE HAZARDOUS LOCATIONS

Courlesy , Walter Kadde & Company

LOCAL APPLICATION CARBON DIOXIDE PROTECTION FOR LEATHER COATING MACHINE

Common Hazards

Ordinary hazards found in all types of manufacturing plants should not be overlooked in the chemical industry. Boiler rooms, engine rooms, maintenance shops, warehouses, and shipping rooms should be in separate fire divisions. Where buildings are of combustible construction, proper clearances should always be maintained to boilers, furnaces, stills, kettles, etc. When repairs become necessary on machinery and e q u i p ment used in process divisions, special supervision should be given to the repair crew. First the safe condition of the equip- ment undergoing repairs should be checked, particular atten- tion should be paid to such operations as cleaning out and steaming of equipment where hazardous liquids and vapors have been used, and extreme caution should be demanded in the use of torches and other equipment by the workmen.

Electrical Hazards Too much stress cannot be placed on the proper installa-

tion of electrical wiring. Either for power or light, all wiring should be installed in strict accordance with the rules of the National Electrical Code. This code is revised biannually, and special rules are set up for the installation of wiring in hazardous locations. Vapor-proof switches and globes, con- duit wiring, and explosion-proof motors play a large part in the safeguarding of hazardous operations. The plant elec- trician should be thoroughly familiar with this code, and his work should be checked by an authorized inspector.

Miscellaneous Hazards General housekeeping should not be overlooked. The

handling of oily waste, rags, and rubbish, oil-soaked wood floors, wood lockers for oily clothing, the smoking hazard, the han- dling and storage of combustible packing materials, all are important items to watch in fire prevention. These hazards can be eliminated from chemical plants without changing process or equipment. They are mentioned as a reminder that they are causative hazards which have a long criminal record in fire-loss history.

After all precautionary measures have been taken, one wonders whether i t is necessary to take steps toward fire protection. Even with fireproof construction and the proper

Ixl~i~si’lil<4i. \ S i ) l ~ l ~ l x l < i i i l ~ l ~ ( : i l l ~ ~ M l s r i ~ Y \ 01.. 2; . 41). I I

particular prirceas or oireratimi iind its cost uf replaceinent is greatly exceeded by the loss of earnings of the plant during the shutdown for reconstruction.

General Considerations

1308

Fires i n some types of cliemical plants require special iuethods Eor their control. Use of water may cause them to spread or increase in intensity. Explosions or the generation of poisonous gases may prevent. firemen from approachin tlre sent of the blazc. It is important in plarits of this t that the skilled xsorkmen be instrncted and trained in what to do in an emergency, and in where to locate and how t o operate their fire-fighting equipment. ’L\’herc a plant is not protected liy a city fire department, a fire brigade should be organized arid drilled rezulnrlv under the supervision of demrtnientnl

Coisrteali, .4morico,z-LaFinncr i ind Fonmilr I n d u ~ l ~ l i r , I w .

Struori~o .AN A L F ~ T ~ : Ex~rlvsuisrrsn nx A N O r r . SWWCIX FIZW

.,~grcgatiiii~ and iafcguariling of all li>~zards, a plant inigirt still be subject to severe loss by fire or explosion iE the means w r e not provided to control small incipient fires. These arc l x n ~ i i r l to occiir rind every plant should be prcpnred Eor t h e m

Chemical Extinguishers several types of first-aid fire-fighting equipment a

:tlj!e. Their extingnishing effect depends upon either blankrt- ing or cooling t.he fire. IIccaiise of specialized suliervisim and imnrance regulations it is best to use only those eat,inguislicrs Iiited by the Underwriters’ Laboratories. They slionld he distributed in the buildings and secbiims wiiere they arc rec- ogiiioed as adapted and most effective Eor nso on tile type <,E firo likely to occur there. These types are divided ronglily into three classes: (1) wood, textiles, rulhistr, and other solid or fibrous combustible materinls where a coding effect, or qucnrhing, is desirable; (2) oils, greases, and similar prod- ucts where the blanketing effect, wtiich excludes oxygen, is most ellective; (3) electrioal fires, including electrical n u - cliiilery, autoniihiles~ trucks, ete., which also require n t h l - keting c!frect. The c:xt,inguishing agents vary from water wiiir,h is expelled either by a cartridge of carbon dioxide, by the action of sulfuric acid 011 bicarbonate of soda, or by other

~aclions mliicli forni a Inam to blanket and qnencli a fire, ) carlron tetraclilrrrido, earhori dioxide, and dry powders. rnin the latter two, a free gas is tlie actual cxtinguishiw

AuLoinatic Sprinklers l‘lie outstanding means OS affordiii$.proteoti”i, againkt fire

i _ :iutoniatic sprinliler equipmerit. This equipment 1ia.s proved sc cffcctive in controlling f i r s and preserving tile arid pruii- w t y t,tiat the majority of the larger innnufacturing and irrcrcantile properties liave now installed it. In the congested districts of a nmnher of American cit,ies its installation in liiiildiogs US combustible construction has been rmde com- pilsory by law.

A mmpletc i,istnliathm of approved automatic sprinkier vquipment iii thc chemical industry in building? of coni- Imvt i i i l e construetimi, or t h e housing coinlnAihle contents, is Iiiglily desirable. Due cuniideration mnst be given t o tlre effcct of watcr on the chemicals involved. Approximately 95 per cent of the fires occurring in plants under sprinkler I,rotcction are cuntrolled by the opening of twenty-fivesprink- ler heads or lesa. The necessity of automatir fire protection i s particularly great in the chemical industry where the ma- d i i ne ry and eqnipnmit used is often of speci;rl design for one

agi:tlt f i i r l d .

.. . hca,ds. Where special conditions exist, as already outlined, the plant fire brigade should he trained to cooperate with the local fire department. Wa.tclimen should patrol the premi tit, rcgnl:w intervals.

Conclusion Vie insurance ratcs are estilblislied, hi geiieral, by a central

rating bureau; all fire iniiirance companies siibscrilx~ to the rates establislied by the bureau in their territory. Several systems oE rating me in iisc ii i the vnrioos scctions of this country Imt all arc based uii e same general principles-- analyzing and charging f i x h r i l s and alloving credits for protective featare.. The rat,ing organizations tnid tlie fire insurance mmpuiies staiid ready atid willing to couperate in every wa,y with those who :ire interested in reducing fire liaznrrls to a qininii im. Plaw nnd sperificat.ioiis snlmiitted to t.lreni reccive t,lio ~ttcnt, ion of specially trninad enginerrs who may be able to point ant in advance rnodifieations mhich, while uot affertilig the operation of the plant, teiid to lessen the I~azards and tlierchy reduce the fire insiiraiice cost.

Conservation alone makes the fire prevention problem of vital indorest t o cliemists, engineer., and ereryone. Property once destroyed hy fire is forever h i s t t o mankind; tlie iiwners iriay be indemnified by insurance lint t,hn property itiplf can uever be replaced. Ilecmvso April 27, 1985.