Method and device for unidirectional airflow in cleanroom

• US 5,620,369 A
• Filed: 06/06/1995
• Issued: 04/15/1997
• Est. Priority Date: 03/22/1994
• Status: Expired due to Term

• Current Assignee: DAW Technologies, Inc.
• Original Assignee: DAW Technologies, Inc.
• Inventors: Brewer, David L., Daw, Ronald W., Spransy, Peter J.
• Primary Examiner(s): Joyce, Harold
• Application Number:
  US08/465,745
• Time in Patent Office: 679 Days
• Field of Search: 454/187, 454/293, 454/294, 454/295, 55/355, 55/385.2, 55/484
• US Class Current: 454/187
• CPC Class Codes: F24F 3/167 Clean rooms, i.e. enclosed spaces in which a uniform flow of filtered air is distributed air distribution by perforated walls F24F7/10

Abstract

A ceiling structure within a cleanroom, including an array of cleanroom filters supported in openings of a grid support structure, wherein the ceiling structure includes a gel track coupled either at the top of the grid support channel. The cleanroom filters including a peripheral flange are suspended in the ceiling structure by having a ceiling edge of the peripheral flange either immersed in the gel track at the top of the grid support structure or using a cleanroom filter having gel or the lower knife edge seal thereof engaging a portion of the top of the grid support channel. Filtered air passes through the channel structure into the vortex region to reduce the vortex region or dead air space below the channel as well as prevent the accumulation of particulate material in the interior of the channel. A damper may be provided with the grid support structure to control the flow of filtered air into the interior of the grid support structure.

Claims

1. A ceiling structure forming a ceiling within a cleanroom, said ceiling structure including a grid support structure forming rectangular openings in said ceiling structure and an array of cleanroom filters formed by a plurality of rectangular filters, each rectangular filter of said plurality of rectangular filters having an upper surface, lower surface, and a periphery supported above said rectangular openings foraged by said grid support structure of said ceiling structure, said plurality of cleanroom filters filtering air flowing into said cleanroom, said grid support structure including:

a plurality of crossmembers forming said rectangular openings in said grid support structure, the plurality of crossmembers supplying the load bearing support for said ceiling structure, each crossmember of the plurality of crossmembers including;

a crossmember having a top wall, a first side wall having at least one aperture therein to allow a portion of said air exiting said rectangular filters to flow therethrough into the crossmember, a second side wall having at least one aperture therein to allow a portion of said air exiting said rectangular filters to flow therethrough into the crossmember, and a gel track formed proximate the top wall of each crossmember of the plurality of crossmembers of said grid support structure forming said rectangular openings and formed near said perimeter of each of said rectangular openings in said grid support structure of said ceiling within said cleanroom formed by the plurality of crossmembers;

each rectangular cleanroom filter of said rectangular cleanroom filters including an upper surface, a lower surface, a periphery, and a peripheral flange located proximate the lower surface and extending about the periphery, the peripheral flange having a sealing edge extending proximate the lower surface of each of said rectangular cleanroom filters substantially about the periphery thereof suspended within the gel track in sealing engagement therewith formed by the plurality of crossmembers forming the grid support structure for said ceiling structure; and

at least one elongated light installed within at least a potion of one crossmember having said at least one aperture in the first side wall thereof and said at least one aperture in the second side wall thereof of said grid support structure thereby allowing the portion of said air flowing through the at least one aperture in the first side wall and the at least one aperture in the second side wall in said at least one crossmember of said plurality crossmembers of said grid support structure to flow therearound thereby exiting said at least one crossmember of said plurality of crossmembers of said grid support structure.

2. A structure as defined in claim 1, further including:

an elongated open light diffuser located proximate the bottom of said grid support structure for allowing the air exiting said cleanroom filters to flow through said grid support structure into said cleanroom.

3. A structure as defined in claim 2, further including:

resilient attachment means for releasably securing the open light diffuser to said grid support structure.

4. A structure as defined in claim 1, further including:

screen diffuser apparatus located below each cleanroom filter of said array of cleanroom filters; and

an isolation seal located between the outer periphery of each screen diffuser means and the grid support structure.

5. The structure as defined in claim 4, wherein the screen diffuser apparatus are supported by said grid support structure.

6. A ceiling structure forming a ceiling within a cleanroom, said ceiling structure including a grid support structure forming rectangular openings in said ceiling structure and an array of cleanroom filters formed by a plurality of rectangular filters, each rectangular filter of said plurality of rectangular filters having an upper surface, lower surface, and a periphery supported above said rectangular openings formed by said grid support structure of said ceiling structure, said plurality of cleanroom filters filtering air flowing into said cleanroom, said grid support structure including:

a plurality of crossmembers forming said rectangular openings in said grid support structure, the plurality of crossmembers supplying the load bearing support for said ceiling structure, each crossmember of the plurality of crossmembers including;

a crossmember having a top wall, a first side wall having at least one aperture therein to allow said air to flow therethrough, and a second side wall having at least one aperture therein to allow Said air to flow therethrough;

a gel track formed proximate the top wall of each crossmember of the plurality of crossmembers of said grid support structure forming said rectangular openings and formed near said perimeter of each of said rectangular openings in said grid support structure of said ceiling within said cleanroom formed by the plurality of crossmembers;

each rectangular cleanroom filter of said rectangular cleanroom filters including an upper surface, a lower surface, a periphery, and a peripheral flange extending about the periphery, the peripheral flange having a sealing edge extending substantially about the periphery thereof being suspended within the gel track in sealing engagement therewith formed by the plurality of crossmembers forming the grid support structure for said ceiling structure thereby preventing the flow of said air therethrough;

at least one elongated light installed within at least a portion of one crossmember having at least one aperture in the first side wall thereof and at least one aperture in the second side wall thereof of said grid support structure thereby allowing the portion of said air flowing through the at least one aperture in the first side wall and the at least one aperture in the second side wall in said grid support structure to flow therearound thereby exiting said at least a portion of one crossmember of said plurality of crossmembers of said grid support structure; and

damper apparatus movable within said support structure to vary the open area of the at least one aperture in the first side wall and the at least one aperture in the second side wall of one crossmember of the plurality of cross members of in the grid support structure.

7. A cleanroom ceiling for a cleanroom, said cleanroom ceiling comprising an array of rectangular cleanroom filters supported within a grid support system, each rectangular cleanroom filter of said array having a filter support flange extending about the periphery thereof, said array of cleanroom filters filtering air flowing into said cleanroom, said grid support system including:

a rectangular matrix formed by a plurality of interconnected load bearing cross members providing load bearing support to said cleanroom ceiling structure, the plurality of cross members forming a plurality of rectangular filter insert openings between adjacent cross members, each load bearing cross member of the plurality of cross members including;

a crossmember having a top wall, a first side wall having at least one aperture therein to allow a portion of said air to flow therethrough, and a second side wall having at least one aperture therein to allow a portion of said air to flow therethrough;

a gel track support channel formed proximate the top of each load bearing cross member to receive a portion of said filter support flange within the gel track support channel; and

one or more elongated lights installed within the cross members and allowing air exiting the aperture in the first side wall thereof and the second side wall thereof of the cross member of the plurality of cross members to flow therearound and exit the cross members into the vortex space therebelow.

8. A structure as defined in claim 7, further comprising a diffuser screen positioned below each rectangular insert filter opening of the rectangular filter insert opeings and approximately flush with the bottom surfaces of the cross members.

9. A method for preventing accumulation of particulate material from a vortex or dead air space immediately below cross members forming a grid matrix which supports cleanroom filters above a cleanroom enclosure, said method comprising the steps of:

suspending the cleanroom filters substantially above openings of the grid matrix and between cross members by placing a peripheral support flange of the cleanroom filters in a track support channel attached at a top side of the cross members;

positioning of a screen below the cleanroom filter;

forming a pressure chamber between the cleanroom filter and the screen;

forming apertures in said cross members;

forcing air through the cleanroom filter and into the pressure chamber, with a resultant airflow passing therefrom into the interior of said cross members via said apertures as well as passing vertically downward through the screen thereby preventing the accumulation of said particulate material in said vortex or dead air space immediately below said cross members; and

varying the area of said apertures to vary the flow of the air therethrough into the interior of said cross members.

10. A ceiling structure forming a ceiling within a cleanroom, said ceiling structure including a grid support structure forming a rectangular openings in said ceiling structure and an array of cleanroom filters formed by a plurality of rectangular filters, each rectangular filter of said plurality of rectangular filters having an upper surface, lower surface, and a periphery supported above said rectangular openings formed by said grid support structure of said ceiling structure, said plurality of cleanroom filters filtering air flowing into said cleanroom, said grid support structure comprising:

a grid support structure including a plurality of elongated cross members, each having at least two side walls having, in turn, a plurality of apertures therethrough and having an elongated rectangular shaped interior space;

at least one elongated light fixture disposed within said elongated rectangular shaped interior space of the plurality of elongated cross members;

a gel track integrally associated with the elongated cross member, said gel track being positioned above the light fixture; and

each rectangular filter of said plurality of rectangular filters having a peripheral sealing edge located at said lower surface of said rectangular filter, the sealing edge being positioned in the gel track sealingly engaging the gel track to prevent said air flow therethrough wherein said air flows from said plurality of rectangular falters, through said apertures in the side walls of the elongated cross members, through the rectangular cross section of the elongated cross members, around the at least one elongated light located in the rectangular cross section of the elongated cross members, and from the plurality of elongated cross members into said cleanroom.

11. A method for preventing the accumulation of particulate material m a vortex or dead air space immediately below and in the interior cross members forming a grid matrix which supports cleanroom filters above a cleanroom enclosure, said method comprising the steps of:

suspending the cleanroom filters substantially above openings of the grid matrix and between cross members by placing a peripheral support flange of the cleanroom filters in a gel track support channel attached at a top side of the cross members;

positioning of a screen below the cleanroom filter;

forming a pressure chamber between the bottom of the cleanroom filter and the screen;

forming apertures in said cross members;

forcing air through the cleanroom filter and into the collection chamber, with a resultant airflow passing therefrom into the interior of said cross members via said apertures as well as passing vertically downwards through the screen; and

varying the area of said apertures to vary the flow of the-air therethrough into the interior of said cross members.

12. A ceiling structure forming a ceiling within a cleanroom, said ceiling structure including a grid support structure forming rectangular openings in said ceiling structure and an army of rectangular cleanroom filters having an upper surface, lower surface, and a periphery supported above said rectangular openings formed by said grid support structure of said ceiling structure, said grid support structure including:

a gel track formed proximate the top of said grid support structure forming said rectangular openings near an interior perimeter of each of the rectangular openings in said grid support structure of said ceiling within said cleanroom;

said rectangular cleanroom filters each including a peripheral flange having a sealing edge extending from substantially adjacent said lower surfaces of each of said rectangular cleanroom filters about said periphery thereof, each of said rectangular cleanroom filters having the sealing edge of the peripheral flange suspended within the gel track;

apertures in said grid support structure for allowing air exiting said rectangular cleanroom filters to flow through said grid support structure into said cleanroom;

one or more elongated lights installed within said grid support structure and allowing air exiting the apertures in said grid support structure to flow therearound and exit said grid support structure;

screen diffuser means located below said bottom surface of each said cleanroom filter of said array of cleanroom filters;

isolation seal means located between each screen diffuser means and grid support structure; and

damper means slidably movable within said grid support structure to vary the open area of the apertures in said grid support structure.