Abstract: A dust filter having a plurality of flat filter bag cassettes is cleaned by the introduction of a pulsed high velocity jet into each filter bag when a filtering period is terminated. A cleaning period comprises normally 20-50 pulses. The jets eject from expansion nozzles at a super-sonic velocity.

Abstract: In order to clean collected dust particles periodically from a filter, for example in a sampling line (16) for removing waste gases from a steelmaking process for analysis, the filter (17) is first pressurised on both sides and the pressure is then suddenly released on the inlet side of the filter (V8) to shock the deposited particles free of the filter element. A continuous reverse flow through the filter of purging gas may follow to clear dust from the system.

Abstract: A flow-reversing, regenerative, desiccant air dryer system absorbs moisture, oil droplets, and carbon particles from the incoming air during compression in a compressed air system. Once sufficient air pressure has been attained in an air pressure reservoir, control valves direct the flow of atmospheric-pressure air, heated by passing through the warm compressor cylinder, in a reverse direction through the air dryer. The reverse flow of heated, atmospheric pressure air both purges the trapped oil, carbon particles, and condensed liquid water and removes the moisture from the desiccant.

Abstract: A filtering device is disclosed for removing particulate solids from a continuously flowing gas stream and which comprises a filter chamber that contains filter bags from which filtered gas is discharged into a plurality of plenum chambers arranged in a radial pattern around the axial center line of the filter. A pressure blower for a cleaning gas is located centrally with respect to the plenum chambers, and the casing of the blower is intermittently revolvable and has an outlet which sequentially falls into alignment with outlets in the plenum chambers through which filtered gas normally flows outward, but through which the cleaning gas is injected inwardly when aligned with the outlet of the blower casing, thereby providing means for intermittently reversing the gas flow in the filter bags and momentarily generating a pressure therein which is greater than exists in the filter chamber.

Abstract: Apparatus for producing dry compressed air comprises a compressor, a separator to remove condensates, an adsorption filter to filter and dry the air and a storage tank. A valve for controlling reverse flow of air from the storage tank through the filter to the atmosphere to regenerate the adsorption filter when the compressor stops is controlled by a moisture sensitive device so that reverse flow is permitted only if the moisture control of the compressed air is above a predetermined value. The opening of a tap to discharge collected liquid from the separator is controlled by a pneumatically operated valve system so that no electrical control is required.

Abstract: Direct current circuitry for sequentially energizing two or more motors or ther load devices, using capacitive discharge to latch in a relay for each load device. During one stage of operation a relatively small voltage is impressed on one lead of a capacitor whose other lead is grounded; a charge is thereby developed in the capacitor. Subsequently a relatively large voltage is impressed on the other lead of the capacitor to direct the charge into the coil of the relay, thereby effecting a relay latching action. The capacitor thereafter isolates the latching circuit from a de-latching circuit; the de-latching circuit is part of a latching circuit for a second relay used to energize a second load device. The invention is particularly useful in sequentially operating electric motors used in self-cleaning engine air cleaners.

Abstract: In a filter box a first air flow generating unit drives air, containing solid impurities, through a filter disposed upstream of said unit. Without interrupting the drawing of impure air into the filter box, the filter is periodically cleaned by drawing auxiliary air through the clean side of the filter by a second air flow generating unit for dislodging and carrying away impurities accumulated on the work side of the filter. The drawing of impure air into the filter box is effected by the second air flow generating unit during the periodic cleaning operation.