Study On The Process Of Hot Gas Cleaning With Porous Metal Candles By Experiment And Numerical Simulation

Gas filtration at high temperatures is widely involved in various fields in the modern industries. It is one of the key technologies in offering various advantages in terms of increasing process efficiency, improving the recovery of heat and materials resources and an advanced environmental protection technology as well. In the gas cleaning process at high temperatures, the regeneration of the filter elements or removal of the dust cake by a pulse gas jet ( a gas jet at high speed generated by high pressure is applied to blow off the dust cake) is crucial and ensures the continuous operation of the filtration-cleaning cycles.In this paper, the experimental study on the effects of different factors on the processes of the filtration and the regeneration is first presented. The profiles of the pressure drop and the temperature variation within the filtration-pulse jet cleaning are provided.Based on the experimental study, a two dimensional axis symmetrical numerical model is set up to simulate the momentum and heat transfer involved in the filtration-pulse jet cleaning process with metal filter candles at high temperature gas cleaning. The CFD algorithm of SIMPLEC is used and the comparison is made between the numerical results and the literature results of Cross R. Good agreement is achieved in the prediction of flow field and reasonable temperature distribution. Further numerical simulation of the effect of the structure parameters of venturi on the regeneration process is carried out for a practical metal filter candle with a specific jet nozzle structure. An appropriate distance of the jet nozzle-venturi is obtained. The cleaning effects with a 310S metal filter candles for with and without venturi are compared. Thence, the discussion of the effect of the permeability and thickness of the candle wall on the pulse jet cleaning is made, which would provide useful advices on the design and operation of the filter components.Finally, the numerical simulation of the fluid flow and heat transfer for the whole process of filtration and pulse jet cleaning is carried out to illustrate the panorama of the transport phenomena.It is depicted that the numerical simulation method based on Computational Fluid Dynamics (CFD) has proved to be advantageous and efficient providing more detailed refined information on the fluid flow and heat transfer, which could be helpful for the operation of Hot Gas Cleaning and providing the direction of optimization of the process.