Industrial air filter

Claim 2

An air filter structure, said structure comprising in combination, an upright casing enclosing a plurality of filter bags, said casing normally open to the atmosphere, an air inlet centrally disposed within said casing and extending axially substantially the length of the filter structure for the reception and passage of an uninterrupted flow of dust laden air to be filtered, a circular walled enclosure integral with the discharge end of said air inlet and defining ports spaced thereabout through which the dust laden air normally passes in an outward direction from said enclosure, said enclosure having a floor against which dust laden air is slowed by impingement thereagainst, a bag mounting plate affixed to the exterior of said circular walled enclosure, filter bags in supported attachment at their lower ends to the bag mounting plate and radially spaced from the air inlet of the filter structure, said filter bags open at their lower end and thereat receiving a flow of dust laden air for travel in a direction opposite to air passing through said inlet, a series of plenums each partially defined by said walled enclosure and said mounting plate with each of said plenums in upstream communication with a port in said walled enclosure and oppositely in communication with the open end of at least one of said filter bags, said plenums further defined by divider wall members contiguous with said enclosure at their inner extremities, and a purge assembly including a traveling purge duct mounted within said walled enclosure for rotation above the enclosure floor and in communication with a remote source of negative air pressure, an upright plate member at the outer end of said duct in unbiased contact with the circular walled enclosure to sequentially close off the ports therein to incoming dust laden air, said plate member additionally defining a purge opening sequentially communicating duct negative pressure to each plenum via a port and to a filter bag associated therewith to impart a reverse flow through the filter bag wall whereby dust particles caked along the bag interior are periodically dislodged from the bag for removal through the bag lower end, a plenum and the purge duct.

Claim 3

The air filter structure as claimed in claim 1 wherein said filter bags are of a woven fabric characterized by a porosity having a 60 to 70 cubic feet per minute per square foot rating.

Claim 4

The air filter structure as claimed in claim 1 wherein each of said plenums is further defined by an inclined bottom wall extending intermediate the periphery of the bag mounting plate and the walled enclosure.

Claim 5

The air filter structure as claimed in claim 3 wherein said bag mounting plate is provided with multiple bag collars of at least two different diameters with each of said collars being in communication with a plenum therebelow.

Claim 6

AOn industrial air filter structure receiving a dust laden airflow from a primary air-particle separator, said filter structure comprising in combination, an upright casing enclosing a plurality of filter bags, said casing normally open to the atmosphere, a tubular inlet centrally disposed within the casing for reception of a downward flow of dust laden air, a walled enclosure of circular configuration integral with the end of said inlet for reception of the dust laden air, said enclosure defining ports spaced circumferentially thereabout through which the dust laden airflow normally passes, a floor extending across and closing the lower end of the enclosure opposite the inlet end, a bag mounting plate affixed to the upper peripheral edge of the walled enclosure, filter bags mounted at their ends to the bag mounting plate and radially spaced from the tubular inlet, said bags receiving at their lower ends a flow of dust laden air for upward passage therealong, a series of plenums circumferentially disposed about said walled enclosure each in communication with one of said ports and with at least one filter bag, each of said plenums defined by upright divider walls, an inclined bottom wall of the filter structure extending intermediate the outer periphery of the bag mounting plate and the walled enclosure, said bag mounting plate and said walled enclosure, and a purge assembly within said walled enclosure and comprising a traveling purge duct in central communication with a continuous source of negative air pressure, an arcuate plate member carried by the duct outer end for moving surfacial contact with the walled enclosure, said plate member defining a purge opening sequentially communicating duct negative pressure to one of said plenums via one of said ports and to a filter bag associated therewith to impart a reverse flow through the filter bag wall whereby dust particles deposited on the bag interior are dislodged from the bag for removal through said one of said plenums and the purge duct, said plate having port blocking surfaces adjacent said purge opening for blocking the entry of dust laden air during arcuate travel of the purge duct past said one port during filter bag purging.

Claim 7

AOn industrial air filter structure receiving a dust laden airflow from a primary air-particle separator, said filter structure comprising in combination, an upright casing enclosing a plurality of filter bags, said casing normally open to the atmosphere, a tubular inlet centrally disposed within the casing for reception of a downward flow of dust laden air, a walled enclosure of circular configuration integral with the end of said inlet for reception of the dust laden air, said enclosure defining ports spaced circumferentially thereabout through which the dust laden airflow normally passes, a floor extending across and closing the lower end of the enclosure opposite the inlet end, a bag mounting plate affixed to the upper peripheral edge of the walled enclosure, filter bags mounted at their ends to the bag mounting plate and radially spaced from the tubular inlet, said bags receiving at their lower ends a flow of dust laden air for upward passage therealong, a series of plenums circumferentially disposed about said walled enclosure each in communication with one of said ports and with at least one filter bag, each of said plenums defined by upright divider walls, an inclined bottom wall of the filter structure extending intermediate the outer periphery of the bag mounting plate and the walled enclosure, said bag mounting plate and said walled enclosure, and a purge assembly within said walled enclosure and comprising a traveling purge duct in central communication with a continuous source of negative air pressure, an arcuate plate member carried by the duct outer end for moving surfacial contact with the walled enclosure, said plate member defining a purge opening sequentially communicating duct negative pressure to one of said plenums via one of said ports and to a filter bag associated therewith to impart a reverse flow through the filter bag wall whereby dust particles deposited on the bag interior are dislodged from the bag for removal through said one of said plenums and the purge duct, said plate having port blocking surfaces adjacent said purge opening for blocking the entry of dust laden air during arcuate travel of the purge duct past said one port during filter bag purging.

Claim 8

The air filter structure as claimed in claim 5 wherein said bag mounting plate is provided with multiple bag collars of at least two different diameters with each of said collars being in communication with a plenum therebelow.

Claim 9

The air filter structure as claimed in claim 5 wherein said purge duct includes scavenging means on the underside of said duct for applying negative duct pressure to the surface of the enclosure floor below said duct for the intake of floor deposited dust particles.

Claim 10

The air filter structure as claimed in claim 7 wherein said scavenging means includes flange means depending from the duct facilitating the pick up of floor deposited dust particles.

Claim 11

The air filter structure as claimed in claim 7 wherein said purge assembly includes a counterweight oppositely located on the duct from said plate member facilitating uniform surfacial contact of said plate member with said circular enclosure, and wherein said plate member includes an overlying plate of friction resistant material to achieve suitable sliding and sealing contact with the walled enclosure defining said ports.

Claim 12

The air filter structure as claimed in claim 9 wherein said filter bags are of a woven fabric characterized by a porosity having a 60 to 70 cubic feet per minute per square foot rating.

Claim 13

In an air filter structure having a plurality of upright filter bags, a circular walled enclosure receiving an axial flow of dust laden air, a series of circumferentially spaced ports in said walled enclosure with each of said ports normally in downstream communication via a plenum with the lower end of a filter bag, a floor closing the lower end of the circular walled enclosure causing the axial flow to be diverted radially through said Ports, the improvement comprising, a rotatable purge assembly centrally journalled within said enclosure including a radially extending purge duct in communication with a source of negative air pressure for bag purging, an upright plate member of arcuate section at the outer end of said duct moving in unbiased contact with the circular walled enclosure to sequentially close off the ports therein to incoming dust laden air, said plate member additionally defining a purge opening sequentially communicating duct negative pressure via one of said ports to the end of a filter bag associated therewith to impart a reverse flow through the bag wall whereby dust particles previously deposited on the bag interior are periodically dislodged from the bag for removal through the bag lower end and the purge duct, said plate member having port blocking surfaces adjacent said purge opening for blocking the flow of dust laden air through the port for intervals preceding and subsequent to alignment of the purge opening with the port permitting purging during arcuate travel of the duct, said purge duct additionally including scavenging means disposed along the underside of said duct for applying negative duct pressure to the subjacent floor surface of the circular walled enclosure for duct intake of floor deposited dust particles.

Claim 14

In an air filter structure having a plurality of upright filter bags, a circular walled enclosure receiving an axial flow of dust laden air, a series of circumferentially spaced ports in said walled enclosure with each of said ports normally in downstream communication via a plenum with the lower end of a filter bag, a floor closing the lower end of the circular walled enclosure causing the axial flow to be diverted radially through said Ports, the improvement comprising, a rotatable purge assembly centrally journalled within said enclosure including a radially extending purge duct in communication with a source of negative air pressure for bag purging, an upright plate member of arcuate section at the outer end of said duct moving in unbiased contact with the circular walled enclosure to sequentially close off the ports therein to incoming dust laden air, said plate member additionally defining a purge opening sequentially communicating duct negative pressure via one of said ports to the end of a filter bag associated therewith to impart a reverse flow through the bag wall whereby dust particles previously deposited on the bag interior are periodically dislodged from the bag for removal through the bag lower end and the purge duct, said plate member having port blocking surfaces adjacent said purge opening for blocking the flow of dust laden air through the port for intervals preceding and subsequent to alignment of the purge opening with the port permitting purging during arcuate travel of the duct, said purge duct additionally including scavenging means disposed along the underside of said duct for applying negative duct pressure to the subjacent floor surface of the circular walled enclosure for duct intake of floor deposited dust particles.

Claim 15

The invention as claimed in claim 11 wherein said purge assembly additionally includes a counterweight oppositely located on the duct from said plate member facilitating uniform surfacial contact of the plate member with said circular walled enclosure.

Claim 16

The invention as claimed in claim 12 wherein said plate member includes an overlying plate of a polymeric material for suitable sliding and sealing contact with the circular walled enclosure defining said ports.