Filter housing

Claim 1

A device for sealably holding a filter, said device comprising: a filter comprising at least one type of filtering material sealed in a frame surrounding and supporting said filtering material, said filter having an upstream side and a downstream side, and a filter holding device that is configured to contain a first side running around the periphery of said filter holding device to form an outer chamber wall, a lip that extends outwardly from the bottom of said first side, a channel bar that is clamped to said lip to form a chamber floor, and a chamber ceiling that extends inwardly from said first side and substantially parallel to said lip, whereby said filter is inserted into said filter holding device to form a chamber around the periphery of said frame of said filter, said frame of said filter forming an inner chamber wall of said chamber, said chamber being connected to an air return for said filter thereby creating a vacuum within said chamber to remove any unfiltered air that bypasses said filter and leaks into said chamber, wherein said filter holding device further comprises: a plenum that defines an air space within said filter holding device above said upstream face of said filter, said plenum having a top and a sidewall, said top of said plenum comprising an opening for receiving unfiltered air, said opening being fitted with an adjustable damper for controlling the flow of said unfiltered air into said plenum, a knife-edge that is embedded in said upstream side of said filter frame, said knife-edge forming a substantially vertical protrusion from said upstream side of said filter frame, a first gasket attached to said chamber ceiling of said filter holding device, said knife-edge making sealing contact with said first gasket to prevent unfiltered air from bypassing said filter and leaking into said chamber, a clamping means to effect said sealing contact between said knife-edge and said first gasket, said clamping means comprising a channel bar, a fastening means, said lip, and channel bar holes in said channel bar to receive said fastening means and thereby clamp said channel bar up towards said lip after said filter has been inserted in said filter holding device, said channel bar being configured to have a body portion, an inner flange, and an outer flange, said inner flange being configured to have a periphery substantially equivalent to the average periphery of said downstream side of said filter frame, said body portion being configured such that said outer flange extends upwardly slightly beyond said lip, a second gasket and a third gasket, said second gasket being of substantially the same configuration as and being attached to said downstream side of said filter frame, said third gasket being of substantially the same configuration as and being attached to said lip, whereby said inner flange of said channel bar comes into sealing contact with said second gasket, and said body portion of said channel bar just inward of said outer flange of said channel bar comes into sealing contact with said third gasket when said channel bar is clamped up towards said lip of said filter holding device after said filter has been inserted in said filter holding device, a perforated screen removably fastened within the inner periphery of said channel bar, said perforated screen serving to evenly distribute the flow of air that passes through said filter, and a hose that is connected between said chamber ceiling and said air return, said hose being subjected to said vacuum and thereby serving to remove from said chamber any unfiltered air that bypasses said filter and leaks into said chamber.

Claim 2

A device for sealably holding a filter, said device comprising: a filter comprising at least one type of filtering material sealed in a frame surrounding and supporting said filtering material, said filter having an upstream side and a downstream side, and a filter holding device that is configured to contain a first side running around the periphery of said filter holding device to form an outer chamber wall, a lip that extends outwardly from the bottom of said first side, a channel bar that is clamped to said lip to form a chamber floor, and a chamber ceiling that extends inwardly from said first side and substantially parallel to said lip, whereby said filter is inserted into said filter holding device to form a chamber around the periphery of said frame of said filter, said frame of said filter forming an inner chamber wall of said chamber, said chamber being connected to an air return for said filter thereby creating a vacuum within said chamber to remove any unfiltered air that bypasses said filter and leaks into said chamber, wherein said filter holding device further comprises: a plenum that defines an air space within said filter holding device above said upstream face of said filter, said plenum having a top and a sidewall, said top of said plenum comprising an opening for receiving unfiltered air, said opening being fitted with an adjustable damper for controlling the flow of said unfiltered air into said plenum, a knife-edge that is embedded in said upstream side of said filter frame, said knife-edge forming a substantially vertical protrusion from said upstream side of said filter frame, a first gasket attached to said chamber ceiling of said filter holding device, said knife-edge making sealing contact with said first gasket to prevent unfiltered air from bypassing said filter and leaking into said chamber, a clamping means to effect said sealing contact between said knife-edge and said first gasket, said clamping means comprising a channel bar, a fastening means, said lip, and channel bar holes in said channel bar to receive said fastening means and thereby clamp said channel bar up towards said lip after said filter has been inserted in said filter holding device, said channel bar being configured to have a body portion, an inner flange, and an outer flange, said inner flange being configured to have a periphery substantially equivalent to the average periphery of said downstream side of said filter frame, said body portion being configured such that said outer flange extends upwardly slightly beyond said lip, a second gasket and a third gasket, said second gasket being of substantially the same configuration as and being attached to said downstream side of said filter frame, said third gasket being of substantially the same configuration as and being attached to said lip, whereby said inner flange of said channel bar comes into sealing contact with said second gasket, and said body portion of said channel bar just inward of said outer flange of said channel bar comes into sealing contact with said third gasket when said channel bar is clamped up towards said lip of said filter holding device after said filter has been inserted in said filter holding device, a perforated screen removably fastened within the inner periphery of said channel bar, said perforated screen serving to evenly distribute the flow of air that passes through said filter, and a hose that is connected between said chamber ceiling and said air return, said hose being subjected to said vacuum and thereby serving to remove from said chamber any unfiltered air that bypasses said filter and leaks into said chamber.

Claim 3

A device for sealably holding a filter, said device comprising: a filter comprising at least one type of filtering material sealed in a frame surrounding and supporting said filtering material, said filter having an upstream side and a downstream side, wherein a knife-edge is embedded in said upstream side of said filter frame, said knife-edge forming a substantially vertical protrusion from said upstream side of said filter frame, and a filter holding device that is configured to contain a first side running around the periphery of said filter holding device to form an outer chamber wall, a lip that extends outwardly from the bottom of said first side, a channel bar that is clamped to said lip to form a chamber floor, and a chamber ceiling that extends inwardly from said first side and substantially parallel to said lip, whereby said filter is inserted into said filter holding device to form a chamber around the periphery of said frame of said filter, said frame of said filter forming an inner chamber wall of said chamber, said chamber being connected to an air return for said filter thereby creating a vacuum within said chamber to remove any unfiltered air that bypasses said filter and leaks into said chamber.

Claim 4

A device for sealably holding a filter, said device comprising: a filter comprising at least one type of filtering material sealed in a frame surrounding and supporting said filtering material, said filter having an upstream side and a downstream side, wherein a knife-edge is embedded in said upstream side of said filter frame, said knife-edge forming a substantially vertical protrusion from said upstream side of said filter frame, and a filter holding device that is configured to contain a first side running around the periphery of said filter holding device to form an outer chamber wall, a lip that extends outwardly from the bottom of said first side, a channel bar that is clamped to said lip to form a chamber floor, and a chamber ceiling that extends inwardly from said first side and substantially parallel to said lip, whereby said filter is inserted into said filter holding device to form a chamber around the periphery of said frame of said filter, said frame of said filter forming an inner chamber wall of said chamber, said chamber being connected to an air return for said filter thereby creating a vacuum within said chamber to remove any unfiltered air that bypasses said filter and leaks into said chamber.