disk stack centrifuge

daniel, emily, etiennepresented by

the outline

• purpose of centrifugation• types of centrifuges• properties disk stack centrifugation• how it works• equipment parts • design considerations • our design• cost estimation• questions and answers

of our presentation

meeting the challenge

a key role in many industrial processes, including the production of insulin, is to separate liquid phases and solids from each other

centrifugation can be utilized to separate the cellular debris from the released protein

purpose of the centrifugation

many fish in the seatypes of centrifuges

decanter centrifuge

disk stack centrifuge

one of a kindproperties of the disk stack centrifugation

ideal for a wide range of separation tasks that involve

particle (biomass) size – 1.5 microns biomass percentage – 0.6%total solid percentage - 5.54%pr

oces

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• lower solids concentrations

• smaller particle sizes

working principleshow 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• less dense liquid phases form concentric inner layers• inserting special plates provides additional surface settling area

working principleshow a disk stack centrifuge works

the whole is the sum of partsparts of the disk stack centrifuge

inlet zone• reduces shear forces and amount of foaming• increases and avoids disturbances of the

separation processes occurring in the bowl

liquid discharge section• important that oxygen pick-up is kept to a

minimum• temperature increases in the liquid must be

avoided to prevent problems later in the process

solids discharge section• remove solids by continuous solids discharge, intermittent solids discharge or

manual removal

the whole is the sum of partsparts of the disk stack centrifuge

disk stack area• heart of the centrifuge• key to good separation performance

lies in the efficiency of the disk stack• layout and design of the distribution

holes ensure that the process flow is evenly spread among all the disks

keys to exceptional performancedesign considerations

efficiency depends on• solids volume fraction• sedimentation area• rotational speed

efficiency can be improved if • particle diameter is increased (coagulation, flocculation)• residence time • distance for sedimentation

keys to exceptional performancedesign considerations

desirables

• high centrifuge speed• large particle size• large density difference between solids and liquids• large radius• small viscosity

our very ownour design

solid wallcontinuous liquids discharge

batch manual solids discharge

throughput

density difference

liquids viscosity

sedimentation area

disk diameter

height

speed

G

motor power

number of disks

134.4 L/min

1.05

0.89 cP

35 m2

0.33 m

0.16 m

5 500 rpm

10 400

6 hp

120

time for shoppingcost estimations

disk stack centrifuge technologymeticulous control, low cost and high reliability

unit cost $166 000 CAD

installation cost $40 000 CAD

he said, she saidreferences

pictures

http://www.flottweg.com/Broschu/%DCbersichtsprospekt_E.pdfhttp://www.alfalaval.com/digitalassets/2/file30910_0_DiscStackBrochure.pdf

websites

http://web.mit.edu/tox/sasisekharan/downloads/BIOT53.pdfhttp://www.sls.hw.ac.uk/icbd/Newsletter/Newsletter_Winter_2005.htm

books

Belter P.A., Cussler E.L., Hu W.S. Bioseparations : downstream processing for biotechnology. New York : Wiley, 1988.

Lydersen B.K., D’Elia N.A.., Nelson K.L. Bioprocess engineering : systems, equipment and facilities. New York : Wiley, 1994.

Perry, R.H.; Green, D.W. (1997). Perry's Chemical Engineers' Handbook (7th Edition). McGraw-Hill.

thank you! questions?