Abstract: A method of feeding out dust in a dust discharge system in a power plant including feeding out dust pneumatically from a separator via a suction nozzle by using transport gas with a pressure exceeding atmospheric pressure, supplying diluting gas into the transport gas at a location close to the suction nozzle of the dust discharge system, and selecting the flow of diluting gas into the transport gas so that part of the pressure drop (.DELTA.Pgas) of the transport gas across the dust discharge system (.DELTA.p) is maintained.

Abstract: A granular media filter has an underdrain system for use in a granular media filter comprising perforated lateral conduits arranged for the distribution of air and water for scouring and backwashing of the filter. Each conduit is in the form of a single linear conduit containing two or more separate axially parallel ducts, each duct having an external wall in common with the conduit, which wall is provided with axially spaced apertures for emission of water or air, there being no intercommunication between the ducts. The underdrain system itself also forms a feature of the invention.

Abstract: A dust suppressor apparatus for use in discharging particulate or granular material, such as grain, which includes a housing defining an internal chamber and having an inlet opening in the upper region of the chamber and a discharge opening in the lower region of the chamber. A suppressor control gate is hingedly mounted on the housing and is biased to a position preventing discharge of material through the discharge opening until a predetermined quantity of particulate material acts on the control gate to overcome the biasing and open the control gate. The control gate and is operative to exert pressure on the particulate material discharging through the discharge opening so as to enable bulk discharge while preventing egress of dust ladened air through the discharge opening. Baffle plates are provided in the chamber to reduce grain velocity within the device. The baffle plates may be independently adjustable or may be automatically adjusted upon tilting of the apparatus.

Abstract: A continuously cleaned bag filter provides a second filter stage for removing dust from air discharged from a cyclone or other primary separator. The primary separator removes the majority of particulate matter from air delivered thereto. In the bag filter dust is filtered from the air, which is discharged through the filter walls. The filtered dust is conveyed along the bottom of the bag filter by an air conveyor and is recirculated back to the primary separator for removal thereat. The air conveyor and a recirculating air blower, the latter providing impetus to carry dust back to the primary separator, are balanced relative to the inflowing air to the bag filter from the primary separator; such balance prevents excessive back-pressure or negative pressure in the filter bags that would otherwise interfere with ordinary air discharge therefrom.

Abstract: A gas transport system for powder has a delivery pipe having an end portion of porous material having a pore size smaller than the particles of the powder. The porous end portion is surrounded by a jacket in which a vacuum is drawn to draw off transport gas and reduce filter capacity which would otherwise be required to remove it. Pulses of pressure are periodically introduced into the jacket to clear particles from the inside of the porous end portion. The vacuum is drawn in the jacket through a vacuum line containing a constriction through which a nozzle discharges high pressure gas at intervals to provide the pulses of pressure in the jacket. This system is particularly effective when used in the production of uranium oxide.