Inside a wet scrubber

Wet scrubbers are used in a range of industries for exhaust gas cleaning and are the Australian sugar industry’s most effective means of removing dust from boiler flue gas, being responsible for significantly reducing its environmental footprint. In virtually all cases, the collection efficiency of wet scrubbers is high enough for boilers with them installed to comfortably comply with the dust emission limits set by environmental authorities. However, wet scrubbers often cause boiler operational problems such as excessive vibration, deposit build-up and wear of boiler induced draft fans due to water droplet carryover and reduced boiler steam output due to blockages in and/or around the scrubber. In some cases, blockages become so severe that a boiler has to be taken off line for scrubber cleaning. Sugar milling operations are adversely affected by the reduced throughput and/or factory stoppages caused by these problems. This paper describes modelling and experimental investigations carried out as part of a project that aims to improve the design and operation of the tangential entry fixed vane wet scrubbers that are widely used in the Australian sugar industry.