1. disk stack centrifuge
presented by
daniel, emily, etienne

2. the outline purpose of centrifugation types of centrifuges
of our presentation
purpose of centrifugation
types of centrifuges
properties disk stack centrifugation
how it works
equipment parts
design considerations
our design
cost estimation
questions and answers

3. meeting the challenge
purpose of the centrifugation
a key role in many industrial processes, including the production of insulin, is to separate liquid phases and solids from each other As
centrifugation can be utilized to separate the cellular debris from the released protein

4. many fish in the sea decanter centrifuge disk stack centrifuge
types of centrifuges
decanter centrifuge As
disk stack centrifuge

5. one of a kind ideal for a wide range of separation tasks that involve
properties of the disk stack centrifugation
ideal for a wide range of separation tasks that involve
lower solids concentrations
smaller particle sizes
1.5 microns = 1.5 x 10-6 m
particle (biomass) size – 1.5 microns
biomass percentage – 0.6%
total solid percentage %
process!

6. working principles
how a disk stack centrifuge works
separates solids and liquid phases from each other in a single continuous process
The area where these two different liquid phases meet is called the interface position. This can be easily varied in order to ensure that the separation takes place with maximum efficiency
Inserting special plates – disk stack – provides additional surface settling area and contributes to speeding up the separation process dramatically.
It is the particular configuration, shape and design of these plates that make it possible for a disc stack centrifuge to undertake the continuous separation of a wide range of different solids from either one or two liquids.
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

7. working principles
how a disk stack centrifuge works As

8. the whole is the sum of parts
parts 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
Very good inlet zone design prevents all foaming
Once separated, the liquid must often be conveyed out of the centrifuge as delicately as possible.
In some applications, it is important that oxygen pick-up is kept to a minimum, and that temperature increases
+ continuous solids discharge: solids and liquid exit via nozzles in the periphery
+ intermittent solids discharge: a carefully designed system opens ports in the bowl periphery at controlled intervals in order to remove the collected solids
+ manual removal, in which the machine is stopped and the bowl is opened so that the collected solids can be removed manually
solids discharge section
remove solids by continuous solids discharge, intermittent solids discharge or manual removal

9. the whole is the sum of parts
parts 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
Disk stack area is the heart of the centrifuge and the design of the disc is therefore crucial
The layout and design of the distribution holes also have a crucial influence on good performance.

10. 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 (coagulation, flocculation)
residence time
distance for sedimentation
(coagulation or flocculation of particles) Coagulation = removal of electrostatic charges
Flocculation = addition of charges to bridge oppositely-charged particles

11. keys to exceptional performance
design considerations
desirables
high centrifuge speed
large particle size
large density difference
between solids and liquids
large radius
small viscosity
(coagulation or flocculation of particles) Coagulation = removal of electrostatic charges
Flocculation = addition of charges to bridge oppositely-charged particles

12. our very own solid wall continuous liquids discharge
our design
solid wall
continuous 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 As

13. time for shopping unit cost $166 000 CAD installation cost $40 000 CAD
cost estimations
unit cost
$ CAD
installation cost
$ CAD As
disk stack centrifuge technology
meticulous control, low cost and high reliability

14. he said, she said references
pictures
websites
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. As

15. thank you! questions?