Study On Flow Field Laws Of Ring Turbulent Buoyant Jet And Control Methods Of Associated Contaminant

Buoyant jet containing dust induced by strong heat source in large spaces is part ofair flow containing dust, fugitive emission in open spaces. This polluted airflow was notcontrolled efficiently in productive process, as a result that it can not only pollute theatmosphere, but also cause serious harms to workers and residents.The critical problem of controlling the dusty airflow is to inspect the characteristicof the flow, then it is designed suitable collecting method and corresponding flowamount, so that we could improve the dust removal efficiency. Theories about round andrectangular turbulent buoyant jet were abundant, yet theories about ring buoyant jet arerelatively seldom. However, in practice there are many ring heat source surface, andmany of the production process can also induce a ring buoyant jet. The aim of this paperis studying the ring buoyant jet induced by high temperature heat source in industrysituation and therefore to guide the industrial precipitation in industrial productionprocedures which exist ring buoyant jet.In this paper, it is suggested that ring turbulent buoyant jet is the superposition ofthermal buoyancy and momentum jet. First, it is got the axis velocity formula and flowflux expression of ring turbulent buoyant jet by theoretical analysis. Second it is builtthe numerical model which applies to simulate thermal buoyant jet, and mastered theboundary conditions. Meanwhile the formulas are verified by numerical simulation andexperimental data got by the predecessor. Then it is simulated the ring turbulent buoyantjet of different actual conditions, and learned the flow field nature of ring turbulentbuoyant jet and change rule of critical section position. Last, according to the flow flux expression and change rule of critical section position, it is determined exhaust air rateand position of the exhaust hood. It is got the good control effect by simulating theresulting exhaust hood parameters.This paper is mainly to get formulas and numerical models to represent andresearch the ring turbulence buoyant jet accurately, and realize the nature of flow fieldin different circumstances. Thus we can remove dust by ventilation more reasonably,efficiently and targetedly instead of designing exhaust hood blindly and tentatively andfinally both achieve industrial precipitation and save energy consumption.