Abstract: An upwash, upflow or downflow, graded sand bed dust collector has a reusable imperforate or slightly porous diaphragm on the top of the graded filter media and an inlet for pressurized gas above the diaphragm for inflating the diaphragm against the media during dust removal stage. The dust collector housing can be flared upwardly and outwardly at selected portions to reduce the velocity of upflowing gas during wash stage for improved grading of the filter media. A natural foraminous layer may be self-grading at the top of the filter media, allowing a circumferential or side outlet for filtrate. A layer of fine, dense filter media may also be used to increase the size range of media particles in the dust collector. Special diaphragms may be composed of individual leaflets that rise above the filter media but not to the level of the gas exit during the wash stage, and which settle on top of the filter media during the filter stage.

Abstract: A canister assembly for containing a particulate desiccant in a housing of a compressed gas filter assembly having for the feed end of a canister a resiliently compressible closure formed of normally spring-spaced inner and outer parts connected for limited relative axial movement, the closure in operative position being contained and releasably locked in the canister with its inner part yieldably engaging an adjoining end of a charge of particulate desiccant.

Abstract: In a compressed gas filter unit including a housing and, for selective filtering, a particulate desiccant packed in a canister removably seatable from below in a central bore of the housing, a pneumatic compactor automatically charged in any filtering cycle of the filter unit and acting upwardly on the desiccant and therethrough on the canister for compacting the desiccant and pressing the canister fluid-tight against a seat therefor at the upper end of the bore.

Abstract: A high performance ventilation system with means for recovering a high percentage of sensible and latent thermal energy from the exhausted air for return via the supply air. Two matrices of thermally absorbent, expanded honeycomb material are respectively alternately interconnected with fan-driven supply and exhaust paths via a valve device to store energy in one matrix while retrieving energy from the other. Constant air flow direction is maintained in the ventilated area. The valve may be thermostat controlled. The matrices are preferably formed of a fibrous organic material such as paper, in an expandable honeycomb configuration, and resin impregnated for durability and strength. A degree of residual flexibility is desired whereby the matrices may be adjusted for fitting, air control and cleaning purposes.

Abstract: Pneumatic compactor for compacting a particulate desiccant in a compressed gas filter unit, the compactor being automatically chargeable with the compressed gas during the unit's filter cycle and manually dischargeable during the unit's drain cycle.

Abstract: A vertically oriented, sheet metal enclosure includes a frusto-pyramidal lower section forming a hopper for separated particulate matter from an air stream which enters a middle section from a downwardly and inwardly inclined inlet duct fixed to one side of that section at the upper end, causing impingement of the airborne particles against the side of the hopper to effect a swirling action to the air stream. An array of laterally spaced, inclined baffle plates at the upper end of the middle section separates the middle section from an upper section which carries tensioned tubular filter bags. An enclosure cover defines an outlet opening feeding to a cover mounted blower.