Studies on sootblower jet dynamics and ash deposit removal in industrial boilers

Sootblowers used to control deposit accumulation on boiler tubes consume substantial amounts of costly high pressure steam; this cost motivates the study of sootblowers and development of improved sootblowing strategies. This paper reviews recent research done on sootblowing at the University of Toronto on three fronts. First, the breakup behavior of brittle deposits impacted by a supersonic gas jet was experimentally studied. Results reveal that crack formation is vital to deposit breakup: to effectively break a deposit, the jet must drill into the deposit and crack it in the short time that the deposit is exposed to the jet. Second, the interactions between a supersonic jet and various tube geometries were visualized to understand sootblower jet flow between boiler tube bundles. Images show that sootblower jet flow and penetration between platens is strongly affected by any interaction between the jet and the first tube of the platen. Finally, a CFD model of a turbulent supersonic sootblower jet was developed. The model yields results that are in good agreement with available laboratory and in situ sootblower measurements.

► Sootblowers consume substantial amounts of costly high pressure steam.
► This motivates the study of sootblowers and improved sootblowing strategies.
► Crack formation is vital to brittle deposit breakup.
► Sootblowing is strongly affected by jet interaction with the first tube of a platen.
► A CFD model of a sootblower jet yields good agreement with measurements.