Flue Gas Flow Dynamics and Deposition of Particulate Matter In-side an Air Sampler Thimble: A Suggestive StudyAuthor(s): Anindya Das Gupta
Flue gas, generated by combustion of fuel particularly solid fuel is usually rich with Particulate Matter (PM) which is a major pollutant for the air pollution issue. The Particulate Matter content may be generated by (a) unburnt carbon particle (b) ash particle (c) condensed gas vapour, particularly if existing below dew point. The flue gas is sampled using a Particulate Matter Collector thimble placed inside a sampling probe tube with a Collector Nozzle attached to a S shaped bent section at the tip of the Probe tube. The probe arrangement is inserted through a sampling hole into a stack and subjected to negative suction pressure generating an induced flue under iso-kinetic condition through the thimble by an external vacuum pump suction. The thimble serves as a screen allowing only flue gas through its pores while obstructing and collecting the Particulate Matter over its internal surface. The following mathematical model investigates the flue gas dynamics through the Thimble and corresponding various forces generated that may contribute for Particulate Matter arrest and deposition inside the thimble.