Centrifuge Machine (Autosaved)

8/9/2019 Centrifuge Machine (Autosaved)

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CANDIDATES DECLARATION

I hereby certify the work which is being presented in this report by entitled in partial fulfillment

of the requirements for the awards of the degree of Master of Science, submitted in the

department of applied physics of the college is an authentic record of my own work carried out

under the supervision of Mrs. Anu Malik.

The mater embodied in this report has been submitted by me for the award of any other.

Pooja Sirohi

This is certify that the above statement made by the candidate is correct to the best of my

knowledge.

Dr. Harsh Mohan Mrs. Anu Malik

Head of the a. Ph!. Dett. Suer"isor


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AC#NO$LED%EMENT

I feel privileged to epress mu unfined thank and deepest gratitude to Mrs. Anu Malik for

providing me an opportunity to work under his kind supervision.

I am highly thankful to !eneral Manager Mr. "arveen Talwar for providing me necessary

facilities and encouragement to carry out this pro#ect.

$ast but not least I am deeply inhabited to my parents without whose content encouragement it

would have not been possible to complete this pro#ect.

Pooja Sirohi

M.S&. Alied Ph!si&s


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CONTENTS

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A""$I(ATI/)S


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CENTRI'(%E MACHINE

(entrifuges are machines used in laborartories, medical facilities 1 industries to separate

suspended material from the mediums they are mied with. This is done by spinning closed

comtainers of the miture very quickly around a fied, central point. The centrifugal force

generated by this motion force the denser material in the motion force the denser material in the

suspension against the walls of the container, effectively separating it from the solution. These

devices are used to separate solids from fluid suspensions medium e.g. they are essential medical

tool for separating plasma from blood samples.

Centrifu)e in li*uid

The core principle of centrifuge operation is centrifugal force. If a bucket half filled with water is

spun quickly in a circle over the head and back down to the ground, centrifugal force created by

the rotation of the bucket forces the water towards the bottom. This is what keeps the water in the

bucket even when its upside down.

Most centrifuges harness this force in a similar way2 and consist of a casing with a lid 1 a drivencentral rotor. The rotor has a row of holes around its circumference into which the containers,

typically test tubes, of solution are placed. /nce the machine lid is closed and the centrifuge

switched on, the rotor spins at high speed. As is the case with the bucket eperiment, the

centrifugal force causes any matter in the solution denser than the liquid to be forced against the

outer walls of the tubes, separating it from the fluid in the process. /nce the centrifuge has

completed its cycle, it is gradually slowed 1 brought to a stop to prevent any turbulence that

could cause the solution to re3mi. This slowing period also allows all the separated material to

drop towards the bottom of the test tube. /nce the rotor has stopped, the tube may be removed

and the sample processed


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AR+C+CLIC CO,ER


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*ig. arcyclic cover

CLAMPS

*ig. clamps


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Prin&ile -Sedientation/

This article is about the scientific phenomenon of sedimentation for sedimentation in the

treatment of water and waste water. Sedimentation is the tendency for particle in suspension to

settle out of the fluid in which they are entrained and come to rest against a barrier. This is due to

their motion through the fluid in response to the forces acting on them. These forces can be due

to gravity. (entrifugal acceleration or electromagnetism.

Sedimentation is often used as the polar opposite of erosion i.e. the terminal end of sediment

transport by saltation or true bad load. Setting is the falling of suspended particles through the

liquid, whereas sedimentation is the termination of the settling process . even small molecules

supply a sufficiently strong force to produce significant sedimentation.

%ra"it! searation

*at globules in milk are lighter than the plasma phase, 1 hence rinse to form a cream layer. The

rate of rise 4v5 of the individual fat flouble can be estimated using stoke6s law which defines the

rate of setting of spherical particles in a liquid.

7 8 4r 94d: 3 d95g 5n

r 8 radius of fat globules

d: 8 density of the liquid phase

d9 8 density of the sphere

g 8 acceleration due to gravity

n 8 specific viscosity of the liquid phase


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AN%LE HEAD

*ig. angle head

particles r 9 ;3 As temperature T: fat epands and therefore r 9 increases. Since the sedimentation

velocity of the particles increases in propotion to the square of the particle diameter a particle of


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radius 9 4r 9 8 ontal

operations combined angle head, with a fied ?@@

spindle angle, combine vertical and hori>ontaloperations on one machine. They increases productively by easy changing the angle of the cutter

while utili>ing the original work piece set up.

/utlet velocity triangles for different blades setting in a centrifugal pump. 'ackward facing for

which the blade curvature Is in a direction opposite to that of the impeller rotation 1 therefore ' 9

?@@ . the outlet velocity triangles for all the cases are also shown BC.9 a, BC.9b, BC.9c from the

geometry of any triangle, the relationship between 7w,+9 and '9 can be written as

7w9 8 +9 = 7f9(ot'9

Dhich was epressed earlier by outlet velocity triangles for different blades setting in a

centrifuge pump. 'etween 9@ to C@@(, milk fat epands faster than the liquid phase on heating.

Therefore the difference between d: and d9 increases with increases temperature.

! 8 Accelaration due to gravity is constant. This will be considered when discussing centrifugal

separation.

) 8 Serum viscosity decreases with increases temperature calculation of the sedimentation

velocity of a fat globule reveals that it rises very slowly, rise is directly proportional to the

square of the radius of the globules. $arger globules overtake smaller ones quickly when a large

globule comes into contact with other globules forming clusters of considerable si>e. These

clusters rise much faster than individual globules. owever, they not behave strictly in

accordance with stoke6s law because they have an irregular shape and contain some milk serum.

In case of forward facing blade, '9 E ?@@ and therefore 7w9 is more than +9. In case of radical

blade '9 8 ?@@ and 7w9 8 +9. In case of backward facing blade '9?@

@ and 7w9 +9 therefore the

sign of F 9, the constant in the theoretical head discharge relationship given by eq. depends

according on the type of blade setting as follows. F 9 @ for radical blades, F 9 E @ for backward

blades with the incorporation of above condition.


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%ER0ER METHOD

The !erber method is a primary and historic chemical test to determine the fact content of

substances, most commonly milk and cream. The !erber method is the primary testing method

in %urope and much of the world. The fairly similar 'abcock test is used primarily in the united

states, although the !erber Method also en#oys significant use in the +S as well.

The !erber Method was developed and patented by r. )iklaus !erber of Swit>erland in :G?:.

Milk fat is separated from proteins by adding sulphuric acid. The separation is facilitated by

using amyl alcohol and centrifugation. The fat content is read directly via a special calibrated

butyrometer. !erber developed speciali>ed butyrometer 4tubes5, pipettes and centirfuges. Dater

baths built specifically for the !erber tubes are often used. The test is still in widespread +S%

T/A0 and is the basis for numerous national and international standards such as IS/;9


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Pro&edure to find fat fro ilk

:. Take :@ml. of !erber 9S/


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'i). fat 2

I**%&%)T M%T/S +S% T/ T%ST T% (/)STIT+%)T /* Milk


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e.g. (ow milk ;


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'acteriological $ab

:. Microscope

9. (olony counter

B. $ovibond comparator


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(haracteristics &equirement

:. /verall length :?@L C9. $ength of neck :


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longitudinal ais of graduated tube. The thickness of the graduated mark shall be not @.:mm

and not E @.9mm. they may be filled with a red coloring matter.

&ange of Scale 1 Scheme of graduations;

a. The main no graduation mark should be carried on complete round of the tube. b. The half graduation mark should comesBK< of the round tube.

c. The smallest graduated mark should comes at least of the round tube

Inscription ; %ach tube shall have permanently and logicly marked on the body

a. -uantity of material to be used i.e. ::.@< ml milk, Cg cream or Bg cheese as

b. HC@(

c. Marker named. Identification of the tube shall be


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SN'

• Darm the milk samples up to :C.C@ ( dge

• Mi the content by inverting the sample upside down and vice versa by taking care to

avoid the formation of bubbles.

• Insert the lactometer gentl2y down to wet stand and allow the lactometer to remain steady

in milk

• Take the reading within B@ sec and also the temp.

• /btain ($&( corrected lactometer reading.

• (alculate J S)* as

J S)* 8 (lrK


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RM ,alue

• Deight accurately C gm of !hee in a polensky flask.

• Add 9@g of glycerol and 9ml of C@J )a/ and few glasses beads.

• eat the flask over naked flame with continuous miing till the ghee becomes clear.

• Measure ?Bml of boiling distilled water and add this to the clear solution.

• Add C@ml value to 9S/


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:. In industries 4washing machines, other grinding machines5

9. In airy *arms 4To separate different products from milk5

B. In medical 4To separate blood corpuscles from infection viruses5

RE'ERENCES


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:. Susan &. Mikkelsen 1 %duardo (ortNn. 'ioanalytical (hemistry, (h. :B. (entrifugation

Methods. Oohn Diley 1 Sons, Mar

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Centrifuge Machine (Autosaved)