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EP0232885A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Method and apparatus for separating liquid compositions on the basis of molecular weight

Assignee: EMD Millipore Corp
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Filing: 1987-02-09
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Granted: —
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Expires: 2007-02-09
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Abstract

Abstract An ultrafiltration device comprising hollow fibers or thin channels through which ultrafiltration of blood plasma is effected is operated under conditions of tangential flow and low conversion. A recirculation stream of high molecular weight fraction of the liquid stream is fed to the device and a permeate stream from the device is recovered. The optimum module aspect ratio is designed and the corresponding maximum shear rate of incoming liquid is specified and controlled so as to provide maximum separation efficiency (selectivity and flux) allowing for separation between species of similar size or molecular weight. Shear rate is controlled by controlling the recirculation stream flow rate. The ratio of the transmembrane pressure at the channel outlet to the transmembrane pressure at the channel inlet resulting from the optimal design and operation is also specified.

Inventors

  • 👤 Anthony J. Dileo
  • 👤 Gaston De Los Reyes

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-10-30 14:58
CPC Classifications
B; B01; B01D; B01D61/00; B01D61/14; B01D61/145; B01D63/00; B01D63/02; B01D2313/00; B01D2313/14

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 188 words
I. A system for separating blood plasma into a high molecular weight stream and a low molecular weight permeate stream which comprises a separation module having separation means comprising a plurality of thin channels or hollow fibers having walls through which ultrafiltration is effected, said separation module having substantially the aspect ratio defined by Equation I and being between about 50 and 5,000, means for introducing said blood plasma into an inlet portion of said separation module at substantially the shear rate defined by Equation 2 and means for removing said high molecular weight stream and said low molecular weight stream from said separation module, means for recirculating at least a portion of said high molecular weight stream to an inlet portion of said separation module thereby to form a recirculation stream, means for controlling the ratio of the recirculation stream flow rate to the permeate stream flow rate to between about 5 and 100 and so that the ratio of the transmembrane pressure at the outlet to said separation means to the transmembrane pressure at the inlet of said separation means to between about 0.0 and 0.85.
Claim 2
Independent Claim 15 words
The system of claim I wherein the aspect ratio is between about 100 and 300.
Claim 3
Independent Claim 26 words
The system of claim I wherein the ratio of recirculation stream flow rate to permeate stream flow rate is controlled to between about 10 and 50.
Claim 4
Independent Claim 33 words
The system of claim I wherein the ratio of transmembrane pressure at the inlet to said separation means to the outlet of said separation means is controlled to between about 0.7 and 0.85.
Claim 5
Dependent Claim 171 words
A process for separating a blood plasma into a high molecular weight stream and a low molecular weight permeate stream utilizing a separation module having separation means comprising a plurality of thin channels or hollow fibers having walls through which ultrafiltration is effected, said separation module having substantially the aspect ratio defined by Equation I and being between about 50 and 5,000 which comprises, introducing said blood plasma into an inlet portion of said separation module and removing said high molecular weight stream and said low molecular weight stream from said separation module, recirculating at least a portion of said high molecular weight stream to said inlet portion of said separation module thereby to form a recirculation stream controlling the ratio of the recirculation stream flow rate to the permeate stream flow rate to between about 5 and 100 so that the ratio of the transmembrane pressure of the outlet to said separation means to the transmembrane pressure at the inlet of said separation means to between about 0.0 and .85.
Claim 6
Dependent Claim 26 words
The process of claim 5 wherein the ratio of recirculation stream flow rate to permeate stream flow rate is controlled to between about 10 and 50.
Claim 7
Dependent Claim 33 words
The process of claim 5 wherein the ratio of transmembrane pressure at the outlet to said separation means to the inlet of said separation means is controlled to between about .70 and .85.

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