Filter cassette for allowing a leak therein to be detected and method thereof

• US 8,308,857 B2
• Filed: 01/08/2009
• Issued: 11/13/2012
• Est. Priority Date: 01/08/2008
• Status: Expired due to Fees

• Current Assignee: SCL Medtech, Inc.
• Original Assignee: SCL Medtech, Inc.
• Inventors: Couillard, Sylvain, Caron, Simon
• Primary Examiner(s): Greene, Jason M
• Assistant Examiner(s): Bui, Dung H
• Application Number:
  US12/350,358
• Publication Number:
  US 20090223372A1
• Time in Patent Office: 1,405 Days
• Field of Search: 73/40, 73/46, 964/21, 964/17, 95/19
• US Class Current: 96/417
• CPC Class Codes: B01D 2273/18 Testing of filters, filter elements, sealings
• CPC Class Codes: B01D 46/10 Particle separators, e.g. dust precipitators, using filter plates, sheets or pads having plane surfaces
• CPC Class Codes: B01D 46/42 Auxiliary equipment or operation thereof

Abstract

A filter cassette and a method for allowing a leak to be detected are disclosed, in which the filter cassette comprises a main body defining a first chamber. The main body includes an inlet and an outlet, a filter separating the first chamber into first and second sub-chambers, the inlet being in fluid communication with the first sub-chamber and the second sub-chamber being in fluid communication with the outlet. The main body also includes a second chamber is defined by the main body and the filter, wherein in absence of a leak the second chamber is substantially not in fluid communication with the first chamber. The main body further includes a port in fluid communication with the second chamber, whereby measuring a fluid characteristic in the second chamber by means of the port allows a detection of a leak, i.e. an external leak or a bypass leakage.

Claims

1. A filter cassette for allowing a leak to be detected, the filter cassette comprising:

a main body defining a first chamber, the main body comprising an inlet and an outlet;

a filter separating the first chamber into first and second sub-chambers, the inlet being in fluid communication with the first sub-chamber and the second sub-chamber being in fluid communication with the outlet;

a second chamber defined by the main body and the filter, wherein in absence of a leak the second chamber is substantially not in fluid communication with the first chamber; and

a port being in fluid communication with the second chamber;

wherein measuring a fluid characteristic in the second chamber by means of the port enables detecting a sufficient leak.

2. A filter cassette as recited in claim 1, wherein the main body comprises a base and a cap separable from the base, and wherein the cap and the base are configured to frictionally fit together.

3. A filter cassette as recited in claim 2, wherein the main body further comprises a ring interposed between the cap and the base.

4. A filter cassette as recited in claim 2, wherein:

the cap comprises;

a first upper portion;

a first lower portion having an external surface, the external surface having a depression; and

a first wall separating the first upper and first lower portions;

wherein the inlet is provided through the first wall;

the base comprises;

a second upper portion having an internal surface;

a second lower portion;

and a second wall separating the second upper and second lower portions;

wherein the outlet is provided through the second wall, and the port is defined through the second upper portion; and

the second upper portion accommodates the first lower portion so as to form the first chamber between the first and second walls.

5. A filter cassette as recited in claim 4, wherein:

the filter is interposed between the first and second walls;

the first lower portion further comprises a lower perimeter; and

the filter is maintained between the lower perimeter and the second wall.

6. A filter cassette as recited in claim 5, wherein:

the second chamber is further defined by the depression on the external surface of the first lower portion and the internal surface of the second upper portion; and

the second chamber communicates with an ambient environment through the port.

7. A filter cassette as recited in claim 5, wherein:

the base comprises a first shoulder about the intersection of the second wall and the internal surface of the second upper portion.

8. A filter cassette as recited in claim 7, wherein:

the base comprises a second shoulder upstream of the first shoulder.

9. A filter cassette as recited in claim 1, wherein a backup pad is provided immediately downstream of the filter.

10. A filter cassette for allowing an external leak or a bypass leakage to be detected, the filter cassette being in an ambient environment and comprising:

a cap having;

a first upper portion;

a first lower portion having an external surface and a lower perimeter, the external surface having a depression;

a first wall separating the first upper and first lower portions; and

an inlet being provided through the first wall;

a base having;

a second upper portion having an internal surface and a port defined therethrough;

a second lower portion;

a second wall separating the second upper and second lower portions; and

an outlet being provided through the second wall; and

a filter;

wherein upon assembly;

the second upper portion accommodates the first lower portion so as to form a first chamber delineated by the first and second walls;

the filter is interposed between the first and second walls and is maintained between the lower perimeter and the second wall; and

the depression on the external surface of the first lower portion and the internal surface of the second upper portion defines a second chamber communicating with the ambient environment through the port, wherein in absence of external leak or a bypass leakage the second chamber is generally isolated from the first chamber.

11. A method for detecting a leak in a filter cassette, the method comprising the steps of:

(a) providing a filter cassette comprising;

a main body defining a first chamber, the main body comprising an inlet and an outlet;

a filter separating the first chamber into first and second sub-chambers, the inlet being in fluid communication with the first sub-chamber and the second sub-chamber being in fluid communication with the outlet;

a second chamber defined by the main body and the filter, wherein in absence of a leak the second chamber is substantially not in fluid communication with the first chamber; and

a port being in fluid communication with the second chamber; and

(b) measuring a fluid characteristic in the second chamber by means of the port.

12. A method as recited in claim 11, wherein the leak is at least one of an external leak and a bypass leakage.

13. A method as recited in claim 11, wherein the fluid characteristic is at least one of a pressure and a flow.

14. A method as recited in claim 11, further comprising in step (b):

obstructing the port;

drawing a vacuum in the first chamber;

measuring a pressure in the second chamber; and

according to a variation of the pressure measured in the second chamber, selecting one of (a) not detecting a bypass leakage and (b) detecting a bypass leakage.

15. A method as recited in claim 11, further comprising in step (b):

obstructing the port;

drawing a vacuum in the first chamber during a time period sufficiently long for bringing the first and the second chambers at a substantial pressure equilibrium;

obstructing the inlet and the outlet;

measuring a first pressure in the first chamber and a second pressure in the second chamber; and

according to a variation between the first and the second pressures, selecting one of (a) not detecting an external leak and (b) detecting an external leak.

16. A method as recited in claim 11, further comprising in step (b):

obstructing the port;

drawing a vacuum in the first chamber during a time period sufficiently long for bringing the first and the second chambers at a substantial pressure equilibrium;

opening one element from the group consisting of the inlet, the outlet, and the inlet and the outlet;

measuring a pressure in the second chamber; and

according to a variation of the pressure measured in the second chamber, selecting one of (a) not detecting a bypass leakage and (b) detecting a bypass leakage.

17. A method as recited in claim 11, further comprising in step (b):

obstructing the port;

generating a flow in the first chamber from one element from the group consisting of the inlet and the outlet;

measuring a first flow in the inlet and a second flow in the outlet; and

according to a variation of the first and second flows, selecting one of (a) not detecting an external leak and (b) detecting an external leak.

18. A method as recited in claim 11, further comprising in step (b):

generating a flow in the first chamber from one element from the group consisting of the inlet and the outlet;

measuring a first flow in the inlet and a second flow in the outlet; and

according to a variation of the first and second flows, selecting one of (a) not detecting a bypass leakage and (b) detecting a bypass leakage.

19. A method as recited in claim 11, further comprising in step (b):

generating a flow in the first chamber from one element from the group consisting of the inlet and the outlet;

measuring a flow in the port; and

according to a variation of the flow in the port, selecting one of (a) not detecting a leak and (b) detecting a leak.

20. A method as recited in claim 18, wherein the leak is selected from the group consisting of a bypass leakage, an external leak and a combination thereof.