The reliability of backwashing valves constituted of first backwashing valves and second backwashing valves is ensured. A first backwashing valve (backwashing-gas rear valve) (7) that controls gas for backwashing and a second backwashing valve (backwashing-gas front valve) (6) that operates at slower speed than the first backwashing valve (7) are disposed, in a series including two or more thereof, at backwashing-gas introducing pipes individually provided for each of the filter blocks.

A dust collection device (1) for removing fine particles from an atmosphere is provided with a filter (3), a blower (11), a dust removal device (7), and a pressure introduction device (9). The filter (3) removes fine particles from an atmosphere drawn into a filter chamber (5A). The blower (11) draws the atmosphere into the filter chamber (5A) and generates an air flow through the filter (3). The dust removal device (7) removes fine particles adhering to the filter (3). The pressure introduction device operates during operation of the dust removal device (7) and introduces an atmospheric pressure higher than the atmospheric pressure inside an air passage to the air passage downstream from the filter (3).

A dust collection device (1) for removing fine particles from an atmosphere is provided with a filter (3), a blower (11), a dust removal device (7), and a pressure introduction device (9). The filter (3) removes fine particles from an atmosphere drawn into a filter chamber (5A). The blower (11) draws the atmosphere into the filter chamber (5A) and generates an air flow through the filter (3). The dust removal device (7) removes fine particles adhering to the filter (3). The pressure introduction device operates during operation of the dust removal device (7) and introduces an atmospheric pressure higher than the atmospheric pressure inside an air passage to the air passage downstream from the filter (3).

Centrifugal turbomachines, such a centrifugal compressors, centrifugal blower, and centrifugal pumps, having unique treatments that enhance their performance ranges. In one arrangement, the treatment involves injecting a relatively high-momentum flow proximate to the blade-tip clearance gap at the inlet to the impeller of the turbomachine in a manner that reenergizes flow at the gap. The injected high-momentum flow can be taken from a location downstream of the outlet of the impeller and/or from a flow external to the turbomachine. In another arrangement, the non-self-bleed-type treatment involves providing the centrifugal turbomachine with a secondary flow path upstream of the inlet to the impeller. In one example, the flow of working fluid to the secondary flow path is modulated according to the mass flow of the working fluid. During times of higher flow, the secondary flow path is opened, and at times of lower flow, the secondary flow path is closed.

A system for cleaning a filter mounted over an intake opening of an air handling unit. A conduit is secured to an elevated location of the unit and includes a plurality of spaced nozzles arrayed against the filter. A supply tube connects to the conduit for supplying a pressurized fluid through the nozzles in order to clear debris from an exterior of the mounted filter. The pressurized fluid includes either of a liquid (typically water) or a compressed air provided from any of a source or a supply reservoir. A pump is incorporated into the supply tube for pressurizing the fluid. A filter incorporated into the supply tube filters the pressurized fluid prior to delivery to spray issuing conduit. A processor/controller is provided in combination with an arrangement of control valves for providing timed sequenced washing of the filters. A collection basin is provided for recycling used liquid for re-delivery and re-use through the spray delivery conduits.