Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.


  1. Advanced Patent Search
Publication numberUS3825175 A
Publication typeGrant
Publication date23 Jul 1974
Filing date6 Jun 1973
Priority date6 Jun 1973
Also published asCA996526A1, DE2426908A1
Publication numberUS 3825175 A, US 3825175A, US-A-3825175, US3825175 A, US3825175A
InventorsW Sartory
Original AssigneeAtomic Energy Commission
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Centrifugal particle elutriator and method of use
US 3825175 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

United States Patent [191 Sartory v CENTRIFUGAL PARTICLE ELUTRIATOR AND METHOD OF USE [75] Inventor: Walter K. Sartory, Oak Ridge,


[7 3] Assignee: The United States of America as represented'by the United States Atomic Energy Commission, Washington, DC.

22 Filed: June 6,1973

21 Appl. No.: 367,684

[52] US. Cl 233/2, 233/15, 233/31 [51] Int. Cl B041) 3/00, B04b 5/06 [58] Field of Search 233/2, 26, 27, 28, 21,

[56] References Cited UNITED STATES PATENTS 3,291,387 12/1966 Billen 233/28 3,519,201 7/1970 Eisel et a1. 233/21 3,703,984 11/1972 Pruessner 233/28 [111 3,825,175 [451 July 23, 1974 FOREIGN PATENTS OR APPLICATIONS 388,966 3/1933 Great Britain 233/15 Primary Examiner-George H. Krizmanich Attorney, Agent, or Firm-John A. Horan; David S. Zachry; John B. Hardaway [5 7] ABSTRACT A method and apparatus for carrying out centrifugal elutriation using a rotatable cylinder having an annular cavity within. Samples are introduced into the cavity at a central part thereof. A suspending liquid is introduced into the cavity at the centrifugal side. A first portion of particles within the sample moves in the centripetal direction with the flowing liquid and a second portion of larger particles moves in the centrifugal direction. Exitports at the centripetal and centrifugal sides of the cavity provide a means for continuously removing the separated first and second portions of particles. p

I 6 Claims, 4 Drawing Figures PATfiN'iiuJuLaamm sum 2 0F 2 FEED CONCENTRATION 7 o .ZEIQDOmTE.

so E

0.2 FEED CONCENTRATION v1 CENTRIFIJGAI. PARTICLE ELUTRIAToR AND METHOD OF USE BACKGROUND OF THE INVENTION This invention was made in the course of, or under, a contract with the US. Atomic Energy Commission. It relates generally to the art of centrifugal elutriation.

The prior art in many areas of technology has used elutriation as a means of separating particles of similar densities but of different effective diameters. The process is based generally upon an application of Stokes Law of sedimentation. The process is applied to particles smaller than about 100 microns. When particle sizes are below approximately 40 microns centrifugation has been used to speed up the settling process.

In the field of blood separation centrifugation has been used in a batch type operation for separating the various constituents. One such prior art technique is that of Lindahl et al., IVA. Tidskrift for Teknisk Vetenskoplig Forskning 26, 309 (1955). This apparatus comprises a cone-shaped inclined cavity within 'a rotating disc, with a side loop attached to the cavity. The inclination and side loop serve the purpose of minimizing recirculation currents and thus mixing. However, even with this design recirculation currents and mixing still occur.

Another such apparatus is described by McEwen et al., Analytical Biochemistry 23, 369-377 (1968). This apparatus comprises a rotatable disc having a kiteshaped cavity in a radial portion thereof. The sample to be separated is pumped into the centrifugal side of the cavity while the disc is rotating. The slower settling particles are thus pumped out of the centripetal s ide of the cavity while the faster settling particles are retained within the cavity. By varying the speed of rotation, various size particles can be pumped out of the cavity one 1 at a time.

Another prior art technique involves the use of a suspending liquid whose viscosity is varied overtime. The settling rate of the particles being separated is effected by the viscosity of the suspending medium in accordance with Stokes Law.

The above prior art techniques generally utilize the concept of flow through a finite void within a rotating disc. Several inherent disadvantages result from such operation. In the above techniques the flowing contents of the cavity come into contact with radial walls during the separation process. This gives rise to Coriolis force effects which cause turbulence along the wall fronting rotation and mixing of the particles which are being separated. Another problem with the above prior art is that the fluid is introduced into the cavity at the section of smallest cross section and moves in the centripetal direction into sections of increased cross section. This causes the overall velocity to decrease as the fluid moves in the centripetal direction. It is known from the technology of fluidization that a high fluid velocity leads to a low particle concentration and, therefore, to

a low suspension density. As a result, the suspension density within the cavity tends to be low at the outer radius, and to increase inthe centripetal direction. Such a density configuration is unstable (like trying to suspend a layer of mercury above a layer of water in a beaker) and will'lead to turnover and turbulent mixing. In

addition, since laminar flow exists at the radial boundaries of the void, the central portion of the fluid has a greater velocity than that of the fluid in the laminar flow of the boundaries. This tends to cause convective mixing. 7

A particular problem with the above prior art processes as they are applied to blood separation, as well as to other separations, is that there is a density gradient in the particlees due to the varied velocities in the different cross sectionarea regions of the void. This results in turbulent mixing of the particles. Another result of the radial velocity gradient is that different shear conditions exist in regions of different velocity. Blood particles are composed of aggregate particles. Under conditions of high shear the aggregates are broken up into primary particles. Underconditions of low shear the particles reaggregate and move in the centrifugal direction only to again be broken up.

In addition to the above problems which militate against achieving any separation at all, the processes are only applicable to batch operation. Thus such systems would not be amenable to a continuous process wherein a particular blood constituent is removed from the blood of a donor, and the remaining plasma and blood constituents are returned to the donor in a single continuous operation.

SUMMARY OF THE INVENTION intermediate the centrifugal and centripetal boundaries of the cavity, evenly flowing a suspending medium from the centrifugal boundary of the cavity toward the centripetal boundary removing faster settling solids and suspending medium from the centrifugal portion of the cavity and removing slower settling particles and suspending medium from the centripetal portion of the boundary.

BRIEF'DESCRIPT ION OF THE DRAWINGS FIG. 1 is a sectional oblique drawing of a rotor housing according to this invention.

FIG. 2 is asectional view of an alternative construction of a rotor housing according to this invention.

FIGS. 3 and 4 are graphs used in determining the overall geometry of a rotor housing according to this invention.

' DETAILED DESCRIPTION According to this invention it has been found that axially extending radial walls may be completely dispensed with in a centrifugal elutriator. A cross section view of the elutriator of .this invention is shown in FIG. I

l. The elutriator is comprised of a housing (1) having a right toroidal cavity (6) enclosed within it. Conduit means -(7), (8), (9), and (10) communicate with the cavity at various locations. Conduit'means (7) serves as an introductory port for suspending fluid used in the process of this invention. Conduit means (10) serves as a sample introduction port. Conduit means (8) and (9) are respectively the centripetal and centrifugal exit ports. The conduit means are pipe-like orifices which pass from the central entrance to their respective openings in the cavity. For small centrifuges (less than about centimeters in radius) a conduit means every 30 or 12 conduit means for each of those illustrated in FIG. 4 is sufficient for satisfactory flow. However, any other arrangement, such as disc-shaped cavities, which allows for uniform flow may be used.

Pervious baffles (2) and (4) through which suspending medium and particles can flow are provided at the centrifugal and centripetal sides of the cavity. Outer baffle (2) is necessary for assuring that the suspending medium, which is introduced through conduit means (7), flows into the central portion of the cavity at an even and uniform velocity around the cavity. Such even flow minimizes mixing effects which would otherwise be present. Inner baffle (4) is not absolutely necessary for the successful operation of the apparatus. However, it is preferred to incorporate baffle (4) into the apparatus so as to minimize and evenly distribute any suction effects which may arise from conduit means (8).

The pervious baffles may be in the form of wire mesh or perforated sheet. It is preferred, however, that the baffles be constructed of porous material having open porosity with a size on the order of the material being separated. Porous polytetrafluoroethylene having a pore size of about 25 microns, which is commercially available, is desirable for use when blood is being separated. The baffles may also be in the form of a packed bed of beads.

Rotor (1) is of the type of construction as is conventional with centrifuges. Appropriately grooved and drilled stacked plates of stainless steel bolted at the periphery provide a suitable construction. However, when blood is being separated it is necessary for the stainless steel to be coated with an inert material such as polytetrafluoroethylene.

Conventional temperature control and rotating means may be employed. For example, the control system used in the K series centrifuge may be employed with the rotor of this invention. Such means are described by Brantley et al. in K-SeriesCentrifuges, Analytical Biochemistry 36, 434-442 (1970).

An alternate form of construction is shown in FIG. 2. In this alternative embodiment, pervious baffle (2') extends only partially across cavity (6) and partition (13) intersects baffle (2') so as to define a flow path for liquid flowing through conduit means (7) through pervious baffle (2'). In this case, conduit means (9) is displaced centrifugally from pervious baffle (2) in areas where no counterflow occurs. Such an arrangement provides for a higher degree of packing of faster settling particles prior to removal.

The process of this invention is generally applicable to particles within the size range of from about 100 microns to 100 A. Although a broad spectrum of particle sizes may exist within the above range, the process of this invention is designed to divide the particles into two groups, one of which is larger than the dividing size and the other of which is smaller than the dividing size. The process of this invention is carried out by the continuous introduction of a sample comprising particles and a suspending liquid into the cavity (6) through conduit means (10) while simultaneously flowing suspending liquid through conduit means (7 while rotating housing (1) at an appropriate velocity. The particles introduced through port (10) tend to move toward centrifugal boundary (12) at varying velocities due to the centrifugal field existing within the rotating housing. Different size particles tend to settle toward centrifugal boundary (12) at different velocities generally as is predicted from Stokes Law. Suspending liquid flowing through conduit means (7) is forced through cavity 6) at a velocity which is intermediate the settling velocities of the particles introduced through conduit means (10). Thus, particles which are settling at a velocity which is greater than the velocity of suspending fluid entering through conduit means (1) move in the centrifugal direction and out through conduit means (9). Particles which are settling at a velocity which is less than the velocity of the flowing suspending liquid move in the centripetal direction and out through conduit means (8). In carrying out the process of this invention there are four flow rates which must be monitored and regulated to achieve satisfactory results. The four flow rates are as follows.

First, the flow of incoming sample through conduit means (10);

Second, the flow of suspending medium through conduit means (7);

Third, the flow of slower settling particles and suspending medium through conduit means (8); and

, Fourth, the flow of rapidly settling particles and suspending medium through conduit means (9).

The first and second flow rates are determined by geometry considerations which are discussed below. The third and fourth flow rates are best determined by regulating the fourth flow rate so as to maintain the radial separation interface of the fast and slow settling particles between conduit means (10) and inner pervious baffle (4). This can be done by observing the separated products or by providing transparent windows in the rotor housing so that the interface may be observed either visually or photometrically. The interface is preferably located centrally between conduit means (10) and inner pervious baffle (4).

In carrying out the present invention the overall geometry of the apparatus must be based upon the particular fluid particle system upon which the apparatus will operate. As an example, an apparatus designed to sepa rate while cells from 1.0 cm lsec. of whole blood with a typical red cell volume fraction of 0.45 is described as follows. A maximum volume of cavity (6) is stipulated as 500 cc since this is a safe volume to remove from a donor.

The sedimentation coefficient of white cells in plasma at 37C is about The sedimentation coefficient of red cells depends on the degree to which individual cells combine to form large aggregates. This tendency varies from individual to individual. Shearing the blood just before sedimentation tends to break up the larger aggregates and thus to reduce the sedimentation velocity. We consider here the value I S 12 X 10 sec. which should be readily attainable with blood from most individuals if severe shearing is avoided. This value allows for a moderate amount of shearing in the tubes and seals which deliver the blood to the separation apparatus.

The volume fraction of white cells (C in blood is normally about 0.002. This small value makes possible a convenient approximation that C is too small to appreciably affect the sedimentation velocities of either red or white cells. ith the aid of this approximation, the plots of FIGS. 3 and 4 have been prepared to aid in determining the size of the apparatus required and the amount of flow which must be pumped through the porous or perforated bafiles.

In FIG. 3, the ordinate is defined as:

red cell throughput FC /w r 21rlS where F volumetric flow rate of blood in the stream feeding the separator (in cm /sec.)

C concentration of red cells in the stream feeding the separator (volume fraction) r is the radial location of conduit means (cm) I is the axial length of the separator cavity (cm) In FIG. 4, the ordinate is defined as: Elutriation flow E/w r 21rlS where E volumetric flow rate of baffle (2) (em /sec.)

In both FIGS. 3 and 4, the abscissa is the concentration of red cells in the stream feeding the separator, Cf.

Since the capacity as shown inFIG. 3is increased by using lower feed concentrations, we dilute the whole blood to a concentration of C 0.30 before introducing it to'the separator. We choose a rotor speed of 700 rpm and a feed port radius of IF 10 cm. These values are convenient and lead to a radial acceleration of about 55 times gravity which does not damage blood cells.

From FIG. 3 at C 0.30 FCf/wirfiZrrlS 0.076 r The axial length of the cavity required is then 1 l= 1.9 cm. From FIG. 4, at C 0.30 E/w r 21rlSg 0.195 The volumetric throughput of plasma through the porous baffles is then E 1.16 cm /sec.

Typical dimensions for an elutriator under the above conditions would then be:

' radius of centripetal wall (11) 6 V2 cm.

radius of centripetal baffle (4) 7 /2 cm.

interface of red and white cells 8 hem.

conduit means (10) 10 cm. centrifugal baffle (2) 10 /2 cmcentrifugal wall (12) 11 V2 cm., and

axial height 1.9 cm.

The above equations and approximations can, of course, be used to determine the elutriator geometry for any system in whichseparation is desired. The process and apparatus'of this invention may also be used in more than one stage. For example, red and white cells may be separated in a first stage and plasma separated from the red'and white cellsv in second and third stages. On the other hand, the products of the first stage may be again separated to achieve a higher separation quality. It is readily apparent that additional plasma through pervious 1. A method for separating particles which are suspended within a suspending liquid, comprising the steps 0 continuously introducing a sam le comprising said particles and said suspending iquid into a central portion of a bound rotatin cavity, a first portion of said particles having di erent settling velocities from a second portion of said particles within said suspending liquid;

flowin a liquid, which is the same liquid as said suspen ing liquid of said sarn 1e, from the centrifugal side of said cavity towar the centripetal side of said cavity at a velocity which is intermediate the settling velocities of said first and second portion of said particles, whereby the faster settling portion of said particles move in the centrifugal direction and the slower settling particles move in the centripetal direction along with said flowing liquid; removin said faster settling 1particles and suspending liquid mm the centrifuga side of said cavity; and

removingsaid slower settling particles and suspending liquid from the centripetal side of said cavity.

2. The method according'to claim I wherein said sample is whole blood, said slower settling particles are white blood cells, said faster settling'particl'es are red blood cells and said suspending liqurd is plasma.

3. A centrifugal elutriator, comprising:

a rotor housing (1) enclosing a right toroidal cavity (6) concentrically located about an axis of said housing, said cavity having a centrifugal bounda'r and a centripetal boundary, said centrifugal boun ary being located at a radial distance from said axis which is greater than the radial'distance of said centripetal boundary from said axis.

first conduit means (7) communicating with said cavity at a point adjacent said centrifugal boundary,

second conduit means (9) communicating with said cavity,

third conduit means (10) communicating with said cavity at a point centripetally located from said second conduit means and generally, centrally located on a radius of said cavity,

fourth conduit means (8) communicating with said cavity at a point centri etally located from said housing at a radius interrne iate said first and third conduit means whereby fluid entering through said first conduit means flows through said baffle to reach any of said conduit means.

4. The apparatus according to claim 3 further comprisin a second pervious baffle (4) located between said t rd and fourth conduit means.

5. The apparatus according to claim 3 wherein said pervious baffle extends across the entire axial height of said cavity.

6. The apparatus according to claim 3 wherein said baffle extends across only a portion of said cavit and a concentric artition extends from said pervious affle to said centri gal boundary, whereby said first conduit means communicates with said cavity within the space defined by said pervious'baffle, said partition and said centrifugal wall and said second conduit means is 10- cated centrifugally of said pervious bafile and on the opposite side of said cavity from said first conduit means.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3982691 *9 Oct 197428 Sep 1976Schlutz Charles ACentrifuge separation and washing device and method
US4193775 *15 Aug 197718 Mar 1980Wang Chia GeeMethods and apparatus for separating gases with ventilated blades
US4290781 *2 Mar 197922 Sep 1981Wang Chia GeeMethods and apparatus for separating gases with ventilated blades
US4670002 *9 Dec 19852 Jun 1987Hitachi Koki Company, Ltd.Centrifugal elutriator rotor
US4689203 *11 Jan 198525 Aug 1987Fluilogic Systems OyCentrifuge
US4939087 *12 May 19873 Jul 1990Washington State University Research Foundation, Inc.Method for continuous centrifugal bioprocessing
US5217426 *14 Aug 19918 Jun 1993Baxter International Inc.Combination disposable plastic blood receiving container and blood component centrifuge
US5217427 *4 Oct 19918 Jun 1993Baxter International Inc.Centrifuge assembly
US5370802 *22 Oct 19926 Dec 1994Baxter International Inc.Enhanced yield platelet collection systems and methods
US5427695 *26 Jul 199327 Jun 1995Baxter International Inc.Systems and methods for on line collecting and resuspending cellular-rich blood products like platelet concentrate
US5529691 *8 Nov 199425 Jun 1996Baxter International Inc.Enhanced yield platelet collection systems and method
US5549834 *30 May 199527 Aug 1996Baxter International Inc.Reduction from a cellular suspension before its separation into a cellular-rich concentration
US5571068 *20 Jul 19945 Nov 1996Baxter International Inc.Centrifuge assembly
US5607830 *9 Feb 19954 Mar 1997Fresenius AgZones for suspension of blood
US5656163 *1 Nov 199312 Aug 1997Baxter International Inc.Chamber for use in a rotating field to separate blood components
US5674173 *18 Apr 19957 Oct 1997Cobe Laboratories, Inc.Apparatus for separating particles
US5690835 *24 Sep 199625 Nov 1997Baxter International Inc.Systems and methods for on line collection of cellular blood components that assure donor comfort
US5722926 *27 Jun 19963 Mar 1998Cobe Laboratories, Inc.Method for separating particles
US5759147 *7 Jun 19952 Jun 1998Baxter International Inc.Blood separation chamber
US5792038 *15 May 199611 Aug 1998Cobe Laboratories, Inc.Centrifugal separation device for providing a substantially coriolis-free pathway
US5804079 *24 Sep 19968 Sep 1998Baxter International Inc.Systems and methods for reducing the number of leukocytes in cellular products like platelets harvested for therapeutic purposes
US5904645 *14 May 199718 May 1999Cobe LaboratoriesApparatus for reducing turbulence in fluid flow
US5906570 *4 Aug 199725 May 1999Cobe Laboratories, Inc.Particle filter apparatus
US5913768 *5 Jul 199622 Jun 1999Cobe Laboratories, Inc.Particle filter apparatus
US5939319 *18 Apr 199617 Aug 1999Cobe Laboratories, Inc.Particle separation method and apparatus
US5951877 *5 Jul 199614 Sep 1999Cobe Laboratories, Inc.Separation of blood
US5954626 *18 Jul 199721 Sep 1999Cobe Laboratories, Inc.Method of minimizing coriolis effects in a centrifugal separation channel
US5993370 *25 Nov 199730 Nov 1999Baxter International Inc.Enhanced yield collection systems and methods for obtaining concentrated platelets from platelet-rich plasma
US6007725 *21 Nov 199728 Dec 1999Baxter International Inc.Separation device, inlet path to convey whole blood from an individual donor into separation device for separation into red blood cells and plasma, anticoagulant including a citrate, return path to convey plasma constituent to donor
US6022306 *5 Sep 19978 Feb 2000Cobe Laboratories, Inc.Method and apparatus for collecting hyperconcentrated platelets
US6051146 *20 Jan 199818 Apr 2000Cobe Laboratories, Inc.Fluidizing a bed of first particles in carrier liquid to retain second particles within a rotating fluid chamber, diluting with lower density liquid to reduce overall density of separated particles and control coriolis force jetting
US6053856 *8 May 199725 Apr 2000Cobe LaboratoriesTubing set apparatus and method for separation of fluid components
US6071421 *25 Nov 19976 Jun 2000Baxter International Inc.Conveying the suspension of platelets from the centrifugal separation chamber to a filter, while maintaining the intermediate layer containing leukocytes inside the centrifugal separation chamber.
US6071422 *26 May 19986 Jun 2000Cobe Laboratories, Inc.Additive substances alter sedimentation velocity of the first particles to modify the filtration characteristics of the saturated fluidized bed.
US6153113 *22 Feb 199928 Nov 2000Cobe Laboratories, Inc.Method for using ligands in particle separation
US618039411 Mar 199730 Jan 2001Bird Engineering B.V.Method of carrying out a treatment in the presence of a centrifugal force and an apparatus therefor
US622801714 May 19978 May 2001Baxter International Inc.Compact enhanced yield blood processing systems
US628062216 May 200028 Aug 2001Gambro, Inc.System for using ligands in particle separation
US633484216 Mar 19991 Jan 2002Gambro, Inc.Centrifugal separation apparatus and method for separating fluid components
US635498616 Feb 200012 Mar 2002Gambro, Inc.Reverse-flow chamber purging during centrifugal separation
US651141113 Sep 200028 Jan 2003Baxter International Inc.Centrifuges used for separation of erythrocytes, platelets and plasma from whole blood; centrifugal forces
US651418930 Oct 20004 Feb 2003Gambro, Inc.Centrifugal separation method for separating fluid components
US67367682 Nov 200118 May 2004Gambro IncFluid separation devices, systems and/or methods using a fluid pressure driven and/or balanced approach
US67733892 Nov 200110 Aug 2004Gambro IncFluid separation devices, systems and/or methods using a fluid pressure driven and/or balanced configuration
US68996667 Jan 200331 May 2005Baxter International Inc.Blood processing systems and methods
US70294301 Nov 200118 Apr 2006Gambro, Inc.Centrifugal separation apparatus and method for separating fluid components
US709419629 Mar 200422 Aug 2006Gambro Inc.Fluid separation methods using a fluid pressure driven and/or balanced approach
US709419712 Apr 200422 Aug 2006Gambro, Inc.Method for fluid separation devices using a fluid pressure balanced configuration
US72018484 Dec 200210 Apr 2007Gambro Bct, Inc.Methods and apparatus for separation of particles
US727910716 Apr 20039 Oct 2007Gambro, Inc.Blood component processing system, apparatus, and method
US749794427 Mar 20073 Mar 2009Caridianbct, Inc.Blood component processing system, apparatus, and method
US75499567 Feb 200623 Jun 2009Caridianbct, Inc.Centrifugal separation apparatus and method for separating fluid components
US758869228 Feb 200715 Sep 2009Caridianbct, Inc.encourage rouleaux of the red blood cells to increase the sedimentation velocity of the red blood cells and enhance their separation from white blood cells
US770888926 Jan 20094 May 2010Caridianbct, Inc.Blood component processing system method
US20130004964 *2 Mar 20123 Jan 2013Roche Diagnostics Operations,Inc.Method for carrying out reactions in an analytical device
DE3635300A1 *16 Oct 198623 Apr 1987Cobe LabZentrifugal-separator
EP0239091A2 *25 Mar 198730 Sep 1987Terumo Kabushiki KaishaParticle separation process
EP0583691A2 *5 Aug 199323 Feb 1994Fresenius AGMethod and device for a continuous treatment of a cellular suspension
EP1555069A1 *18 Apr 199620 Jul 2005Gambro, Inc.,Particle separation apparatus and method
WO1981001801A1 *19 Dec 19799 Jul 1981C WangMethod and apparatus for separating gases with ventilated blades
WO1996033023A1 *18 Apr 199624 Oct 1996Cobe LabParticle separation apparatus and method
WO1997033687A1 *11 Mar 199718 Sep 1997Univ Delft TechMethod of carrying out a treatment in the presence of a centrifugal force and an apparatus therefor
WO1998033597A1 *30 Jan 19986 Aug 1998Australian Red Cross Society WMethod and means for separating blood
WO1999036111A119 Jan 199922 Jul 1999Cobe LabSystem and method for separation of particles
WO2005005460A1 *21 Jun 200420 Jan 2005Marc Antonius Theodo BisschopsMethod of washing and concentrating protein precipitates by means of a centrifugal field and fluidization conditions
WO2006047296A1 *20 Oct 20054 May 2006Cryofacets IncSystem, chamber, and method for fractionation and elutriation of fluids containing particulate components
U.S. Classification494/27, 494/37, 494/36
International ClassificationB04B5/06, B04B5/04
Cooperative ClassificationB04B5/06, B04B5/0442, B04B2005/0471
European ClassificationB04B5/04C, B04B5/06