Exhaust Filter Module, and a Method and Apparatus for Efficiency Testing the Same

• US 20060276120A1
• Filed: 03/21/2006
• Published: 12/07/2006
• Est. Priority Date: 03/21/2005
• Status: Active Grant

• Current Assignee: Camfil USA, Inc.
• Original Assignee: Camfil USA, Inc.
• Inventors: Cherry, John L. Sr., Huza, Mark, Morse, Thomas C., O'Reilly, Sean
• Granted Patent: US 9,976,770 B2
• Time in Patent Office: Days
• US Class Current: 454/56
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/39 Monitoring filter performance
• CPC Class Codes: F24F 13/28 Arrangement or mounting of filters
• CPC Class Codes: G01N 1/22 in the gaseous state specially adapted for biological material G01N33/497; measuring breath flow A61B5/087

Abstract

A filter module configured for exhaust application, and a method and apparatus for testing the same are provided. In one embodiment, the filter module includes a downstream sampling port configured to allow a technician to sample flow, downstream of the filter module, from the cleanroom side of a filter module. In another embodiment, a shroud adapted to sealing engage a filter module under test is provided and includes a tube, disposed in the shroud, that couples a port to a downstream sampling port of the filter module.

Claims

1. A filter module configured for exhaust application, comprising:

a housing having a filter aperture on a room side of the housing, an exhaust port on a ceiling side of the housing, and a downstream sampling port configured to allow a technician to sample flow downstream of the filter module and housing from the room side of the housing.

2. The filter module of claim 1, wherein the housing further comprises:

a tube extending through the housing between the room side and ceiling side of the housing.

3. The filter module of claim 2, wherein the housing further comprises:

a filter-housing sealing interface having one end of the tube sealingly coupled thereto.

4. The filter module of claim 2, wherein the downstream sampling port further comprises:

a ceiling-side downstream sampling port coupled to the ceiling side of the housing and having a first end of the tube sealingly coupled thereto.

5. The filter module of claim 4, wherein the downstream sampling port further comprises:

a room-side downstream sampling port coupled to the room side of the housing and having a second end of the tube sealingly coupled thereto.

6. The filter module of claim 1 further comprising:

a ductwork coupled to the exhaust port;

a filter element disposed in the filter aperture and sealingly coupled to the housing;

a port disposed in the ductwork and coupled to the downstream sampling port of the housing.

7. The filter module of claim 6 further comprising:

a shroud disposed in the cleanroom and sealingly interface with at least one of the filter element, the filter module or a ceiling to which the housing is mounted; and

an aerosol generator arranged to provide an aerosol to a region defined within the shroud.

8. An apparatus for testing a filter element mounted in an exhaust filter module, comprising:

a shroud having a flange for sealing against a cleanroom side face of the filter module and a collar sized to provide a test air flow to the filter element from a blower;

a first port formed through the shroud and configured to sample air in the volume defined between the shroud and the filter element;

a second port is formed through the shroud; and

a flexible conduit coupled to the second port and having sufficient length to extend at least to the flange of the shroud.

9. The apparatus of claim 8 further comprising:

an aerosol injection port form through the shroud;

10. The apparatus of claim 9 further comprising:

an aerosol dispersion device disposed in the shroud and coupled to the injection port.

11. The apparatus of claim 10 further comprising:

at least one mixing element disposed in the shroud.

12. A filter module configured for exhaust application, comprising:

a housing having a filter aperture on a room side of the housing, an exhaust port on a ceiling side of the housing;

a tube extending through the housing between the room side and ceiling side of the housing

a knife-edge filter sealing flange extending into the housing;

a first port formed in the flange and having a first end of the tube sealingly coupled thereto;

a port formed in the ceiling side of the housing and having a second end of the tube sealingly coupled thereto.

13. A method for efficiency testing a filter element mounting in an exhaust configuration, comprising:

positioning a shroud on a room-side of a filter element;

establishing a flow through the filter element in an exhaust direction;

providing an aerosol challenge to the room-side the filter element;

sampling a concentration of the challenge upstream of the filter element;

sampling a concentration of the challenge upstream of the filter element;

and;

calculating an efficiency of the filter element.

14. The method of claim 13, wherein positioning the shroud further comprises:

sealing the shroud to at least one of the filter element, a housing retaining the filter element or a structure to which the housing is mounted.

15. The method of claim 13, wherein positioning the shroud further comprises:

coupling a tube disposed in the shroud to a port fluidly coupled to a downstream aerosol sampling port.

16. The method of claim 13, wherein positioning the shroud further comprises:

coupling a tube disposed in the shroud to a port formed in the filter element or a housing retaining the filter element.

17. The method of claim 13, wherein positioning the shroud further comprises:

coupling a tube disposed in the shroud to a room-side port formed a housing retaining the filter element, the port coupled to a tube extending through the housing to a ceiling-side port formed in the housing, the ceiling-side port coupled to a sampling port disposed in a ductwork down-stream of the filter housing.

18. The method of claim 13 further comprising:

coupling a blower to an end of the shroud opposite the filter element.

19. The method of claim 13, wherein providing the aerosol challenge to the room-side the filter element further comprises:

providing the aerosol challenge through an aerosol inject port into to a region within the shroud; and

drawing air through an aperture of the shroud defined upstream of the aerosol inject port.

20. The method of claim 13, wherein positioning the shroud further comprises:

removing a filter screen posited in front of the filter element from a retainer; and

securing the shroud in front the filter element using the retainer.