2the outline purpose of centrifugation types of centrifuges of our presentationpurpose of centrifugationtypes of centrifugesproperties disk stack centrifugationhow it worksequipment partsdesign considerationsour designcost estimationquestions and answers
3meeting the challengepurpose of the centrifugationa key role in many industrial processes, including the production of insulin, is to separate liquid phases and solids from each otherAscentrifugation can be utilized to separate the cellular debris from the released protein
4many fish in the sea decanter centrifuge disk stack centrifuge types of centrifugesdecanter centrifugeAsdisk stack centrifuge
5one of a kind ideal for a wide range of separation tasks that involve properties of the disk stack centrifugationideal for a wide range of separation tasks that involvelower solids concentrationssmaller particle sizes1.5 microns = 1.5 x 10-6 mparticle (biomass) size – 1.5 micronsbiomass percentage – 0.6%total solid percentage %process!
6working principleshow a disk stack centrifuge worksseparates solids and liquid phases from each other in a single continuous processThe 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 efficiencyInserting 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 processuses extremely high centrifugal forcesdenser solids are forced outwards against the solid bowl wallless dense liquid phases form concentric inner layersinserting special plates provides additional surface settling area
7working principleshow a disk stack centrifuge worksAs
8the whole is the sum of parts parts of the disk stack centrifugeinlet zonereduces shear forces and amount of foamingincreases and avoids disturbances of the separation processes occurring in the bowlliquid discharge sectionimportant that oxygen pick-up is kept to a minimumtemperature increases in the liquid must be avoided to prevent problems later in the processVery good inlet zone design prevents all foamingOnce 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 manuallysolids discharge sectionremove solids by continuous solids discharge, intermittent solids discharge or manual removal
9the whole is the sum of parts parts of the disk stack centrifugedisk stack areaheart of the centrifugekey to good separation performance lies in the efficiency of the disk stacklayout and design of the distribution holes ensure that the process flow is evenly spread among all the disksDisk stack area is the heart of the centrifuge and the design of the disc is therefore crucialThe layout and design of the distribution holes also have a crucial influence on good performance.
10keys to exceptional performance design considerationsefficiency depends onsolids volume fractionsedimentation arearotational speedefficiency can be improved ifparticle diameter is increased (coagulation, flocculation)residence timedistance for sedimentation(coagulation or flocculation of particles) Coagulation = removal of electrostatic chargesFlocculation = addition of charges to bridge oppositely-charged particles
11keys to exceptional performance design considerationsdesirableshigh centrifuge speedlarge particle sizelarge density differencebetween solids and liquidslarge radiussmall viscosity(coagulation or flocculation of particles) Coagulation = removal of electrostatic chargesFlocculation = addition of charges to bridge oppositely-charged particles
13time for shopping unit cost $166 000 CAD installation cost $40 000 CAD cost estimationsunit cost$ CADinstallation cost$ CADAsdisk stack centrifuge technologymeticulous control, low cost and high reliability
14he said, she said references pictureswebsitesbooksBelter 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