An Experimental and Numerical Study on the Cleaning of Pleated Bag Filters Using Low-Pressure Pulsed-Jets

Pulsed-jet cleaning is recognized as the most efficient method to regenerate bag dust collectors traditionally used in industrial processes to control the emission of particulates.In this study,non-woven needle felt filter bags with and without a film coating material have been analyzed considering different geometries(different number N of pairs of pleated filter bag sides)in the frame of dedicated low-pressure pulsed-jet cleaning experiments.The flow structure inside the bag and the response characteristics of its wall have also been analyzed numerically through a computational fluid-dynamics/structural-dynamics(CFD-CSD)unidirectional fluid-solid coupling method.As shown by the experiments,the peak pressure(P_(0))on the wall of the filter bag with N=8 and 12 is higher,which indicates dust can be removed more effectively in these cases.The peak pressure on the wall increases first and then decreases along the direction of the bag length,while the peak pressure of the pleated filter bag with nonwoven needled felt film coating is greater than that without film coating.A comprehensive analysis of the time variation of acceleration,deformation,strain,stress and other factors,has led to the conclusion that the pleated filter bag with N=12 would be the optimal choice.

Separation and cleaning of Leymus chinensis seed threshing material based on gas-solid coupling

The aim of this study was to improve the cleaning performance of the Leymus chinensis seed threshing material separation and cleaning device,and to clarify the movement law and characteristics of the Leymus chinensis seed threshing material during the cleaning process.A numerical simulation of the separation and cleaning process of Leymus chinensis seed threshing material was performed using the computational fluid dynamics discrete element approach.According to the streamline distribution of the gas-solid coupling,the movement of Leymus chinensis seeds during the cleaning process was examined.Additionally,the average speed and quantity of Leymus chinensis seed threshing material in different separation and cleaning zones were studied over time.Meanwhile,the distribution principle of the threshing material was obtained,and a verification test of the under-sieve distribution was conducted.The test results showed that the numerical simulation was consistent with the distribution trend of the under-sieve.The cleaning performance verification test showed that the impurity content and the loss rate of the separation and cleaning device were 27.3%and 3.3%,where the test results,compared with those of the numerical simulation,showed a reduction of 1.5%and 0.8%,respectively.It is feasible to apply the theory and method of gas-solid coupling to simulate the separation and cleaning process of Leymus chinensis seeds.