Mixed gas integrity testing of porous materials without permeate side access

Patent metadata

Field	Value
Publication number	US-10955328-B2
Application number	US-201716349855-A
Country	US
Kind code	B2
Filing date	Nov 20, 2017
Priority date	Feb 22, 2017
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

A method of integrity testing porous materials that is non-destructive to the material being tested. The inlet gas stream includes at least two gases, wherein one of the gases has a different permeability in liquid than the other, such as oxygen and nitrogen in water. The relative permeability of the gases is measured in the retentate stream, thereby avoiding accessing the permeate stream and potentially introducing contaminants to the material being tested. The integrity test is capable of detecting the presence of oversized pores or defects that can compromise the retention capability of the porous material.

First claim

What is claimed is:

1. A method of integrity testing a porous material, comprising:
providing a porous material to be tested, said porous material having an upstream side and a filtrate side;
providing a gas stream comprising at least first and second gases having different permeabilities in a liquid used to wet said porous material;
introducing said gas stream to said upstream side of said porous material;
causing said first and second gases to flow through said porous material;
measuring the concentration of at least one of said first and second gases in a retentate stream exiting said upstream side of said porous material; and
comparing the measured concentration to a predetermined concentration;
wherein a difference between said measured concentration and said predetermined concentration is indicative of said porous material being non-integral.

2. The method of claim 1 , wherein said first gas is oxygen and said second gas is nitrogen.

3. The method of claim 1 , wherein said first gas is oxygen, and wherein said concentration of one of said gases is measured with an oxygen analyzer.

4. The method of claim 1 , wherein said liquid comprises water.

5. The method of claim 1 , wherein said porous material is a sterilizing grade filter.

6. The method of claim 1 , wherein said porous material comprises a membrane.

Assignees

• Emd Millipore Corp

Inventors

• Giglia Salvatore

Classifications

• G01N2015/084

  Testing filters · CPC title

• G01N15/082 Primary

  Investigating permeability by forcing a fluid through a sample · CPC title

• B01D65/102 Primary

  Detection of leaks in membranes · CPC title

• B01D61/38

  Liquid-membrane separation · CPC title

• G01N2015/0662

  Comparing before/after passage through filter · CPC title