A two-reservoir model to simulate the air discharged from a pulse-jet cleaning system

Abstract

This work presents a novel two-reservoir model to simulate, for a pulse-jet cleaning system, the air discharged from an air reservoir via a diaphragm valve to a blowpipe and ultimately into the atmosphere. The air reservoir and blowpipe are referred to reservoir 1 and reservoir 2, respectively. The proposed model consists of (1) a set of governing equations that are solved by a finite difference and (2) an iterative calculation method to describe the physical phenomena. The feasibility of the proposed model is also evaluated via experiments performed herein. Comparing the mass flow rates predicted by the proposed model with those of the benchmark solutions reveals that the model predictions are about 10% overestimated. In addition, the proposed model is more accurately simulated by considering the friction effects induced by the exit of the air reservoir and the nozzles on the blowpipe. The former increases the Mach number of the air and equals that of a frictional pipe of 4fLe/Dh. The latter decreases the mass flow rate discharged from the nozzles. A discharge coefficient Cdn is introduced to represent the ratio of the mass flow rate discharged from a real nozzle and an ideal one. Moreover, experimental methods are developed to determine the values of 4fLe/Dh and Cdn. When the parameters of 4fLe/Dh and Cdn were included in the model, the accuracy of the model predictions was significantly improved. The deviations between the mass flow rates of the model predictions and the bench mark solutions were markedly reduced to 3%. © 1999 Air and Waste Management Association.