Disk Centifuge.ppt s6y3p

Presented by : Hasnain Ali Roll no : 43

Disk centrifuge

The outline of my presentation

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General Idea Purpose Of Centrifugation Types Of Centrifuges Properties Disk Stack Centrifugation How It Works Industrial Application And Uses Design Questions And Answers

General Idea • • •

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Feed added to spinning bowl Sedimentation of particles occurs in centrifugal field Flow is upwards at a particular rate which determines residence time in device Separation happens if sedimentation velocity is high enough for particle to reach side of bowl within residence time Large particles have higher settling velocities than small particles Both large and small are still particles, have small Reynolds no.s (<1) and obey Stokes’ Law

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Centrifuge

Purpose Of The Centrifuge

• A key role in many industrial processes is to separate liquid phases and solids from each other

• Centrifugation can be utilized to separate the cellular from the released protein

The Centrifuge • Separation of milk into skimmed milk and cream is done with a centrifuge

http://www.nzifst.org.nz/unitoperations/mechseparation4.htm

Types of centrifuge 1. Basket Used to separate solids from liquids, where a screen or filter can be used. (Cyclic type operation) 2. Decanter (Horizontal or Vertical Bowl) Used to separate solids from liquids. (Continuous type operation)

3. Vertical Disc Used to separate solids from liquids and separate different density liquids. (Continuous type operation)

Types Of Centrifuges Basket centrifuge

decanter centrifuge

disk stack centrifuge

Decanter Centrifuge - Two Main Types

Vertical

 Horizontal

1.

Slurry enters into the center of the rotating screw conveyor and is discharged into the centrifuge through nozzles.

2.

Centrifugal force causes the material to separate.

3.

The conveyor moves the solids to the tapered end where they are thrown out.

4.

Clear fluid flows out the other end.

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A Common “Basket Centrifuge”

Properties of the Disk Stack centrifugation ideal for a wide range of separation tasks that involve • lower solids concentrations

process!

• smaller particle sizes

particle size – 1.5 microns total solid percentage - 5.54-25%

working principles how a disk stack centrifuge works

• separates solids and liquid phases in a continuous process • uses extremely high centrifugal forces • denser solids are forced outwards against the solid bowl wall •inserting special plates provides additional surface settling area

Working Principles how a disk stack centrifuge works

1.

Liquid or slurry enters into the top of the centrifuge.

2.

The higher density solids get pinned against the outer bowl wall.

3.

The lowest density liquids are forced through the discs and back out through the top.

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Higher density liquids are retained in the space between the discs and the solids and can be piped out.

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A centrifuge of this type may also be known as a clarifier, purifier, or concentrator. http://www.hutch-hayes.com/vertical_disc_applications.htm

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Vertical Disc Centrifuge Cycle Animation

http://www.hutch-hayes.com/vertical_disc_applications.htm courtesy CONTEC 2004

Vertical Disc Centrifuge Equipment

Design of equipment solid wall continuous liquids discharge batch manual solids discharge throughput 134.4 L/min density difference 1.05 liquids viscosity 0.89 sedimentation area disk diameter height speed G motor power number of disks

35 m2 0.33 m 0.16 m 5 500 rpm 10 400 6 hp 120

Keys To Exceptional Performance design considerations

efficiency depends on • solids volume fraction • sedimentation area • rotational speed efficiency can be improved if • particle diameter is increased • residence time • distance for sedimentation

Vertical Disc Centrifuge Uses / Industries 1. Dairy (Cream separators) 2. Food Processing (de-pulping of fruit juice, clarification of apple juice, wine clarification) 3. Marine (remove water from fuel / oil) 4. Offshore Oil (remove oil from water) 5. Environmental (remove oil from water) 6. Machine Tool (remove fine metallic particles from coolant)

Vertical Disc Centrifuge Uses / Industries • Food and Beverage • processing and recovery of non-liquid food products • processing of citrus fruit • wine and sugar processing • recycling of food-related products

Advantages •

The most common advantages of centrifugal sedimentation,better known as Centrifugal Separation are:

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compact size of equipment, low capital investment, versatility, ease of use, low operating costs,

• high performance.

Thank You! questions?