Numerical Simulation Of Flow Field Characteristic Of Long Bags In Bag Filter

Bag filter has become the most widely used mainstream dust removal equipment because of its advantages of high dust removal efficiency,convenient use,economy,and reliability.With the rapid expansion of industrial scale and improvement of technology,bag filter is developing towards large-scale and automatic development.One of the quickest ways is to increase the length of the filter bag,and this method has been widely used abroad.F.LSmidth,a famous manufacturer of dust collectors in the world,has applied 10 m long bags to its products in 2011.Although domestic manufacturers use 10 m bags,it is not common.The reason is that many problems brought about by the growth of filter bags remain unresolved.For example,if the operating resistance of the dust remover is too high,the energy consumption increases;the inhomogeneity between the filter bags also becomes more serious as the length of the filter bag increases;and if the air flow rises too much,dust is difficult to settle,etc.Therefore,this article has studied the above problems,taking 10 m long bags as the research object,using numerical simulation methods to study how to improve the performance of long bag filter.Completed the following main tasks:(1)The parameter of can velocity was studied.In view of the controversy over the definition of this parameter at home and abroad,the distribution of can velocity inside the dust collector was studied using numerical simulation methods;finally,a series of test verifications have been carried out on the factors affecting the rate of air flow rise,and the influence of various factors on the can velocity was analyzed.(2)Through the model reconstruction and numerical simulation of the position of import and export,import and export area and bag spacing,the influence of different structures on the internal flow field of long bag filter was completed.When the position of the entrance and exit is found on the opposite side,that is,the angle between the two is 180 degrees,the uniformity between the filter bags of the dust collector is the best,and the can velocity is at a low value;while increasing the area of the inlet helps to reduce the operating resistance of the dust collector and can velocity;also increasing the longitudinal spacing of the filter bag does not have any effect on reducing the operating resistance of the dust collector,but it can make the air flow distribution more uniform and the value of can velocity also becomes smaller.(3)The dust removal of long bag filter was studied.On the experimental device,a clean air pulse cleaning physics experiment was conducted.Using the sensor measurement data,the same differential pressure at the bottom of the bag as that of Ye Xiaoli et al.was obtained,but a lower injection pressure was used.Then,numerical simulation and semi-physical simulation were performed.The comparison of the results showed that the results of the semi-physical simulation were closer to the physical experiments.Although the numerical simulation results were numerically different,the laws were very similar.