Filter cleaning system and method

A cleaning system for a gas turbine inlet filter mounted to a tubesheet. The filter defines an upstream side at which particulates are separated from a fluid stream passing through the filter and a downstream side substantially free of the particulates. The cleaning system comprises a blowpipe for supplying a pressurized fluid. A one-piece nozzle is made from a tubular member having a substantially constant cross-section extending along the length of the member. The nozzle is permanently attached to the blowpipe at a first end portion. The nozzle is in fluid communication with the blowpipe to direct a cleaning pulse of the pressurized fluid from a second opposite end portion into the downstream side of the filter to dislodge particulates into the upstream side. An aspirator is formed in the nozzle at an upstream location spaced from the second end portion of the nozzle. The aspirator enables an additional volume of fluid to be delivered from the second end portion of the nozzle than is delivered from the blowpipe to the first end portion of the nozzle. A diffuser is fixed to at least one of the blowpipe and the nozzle. The diffuser directs a portion of the cleaning pulse to a proximal portion of the filter located adjacent to the tubesheet.