Optimization Of The Dust Cleaning Performance Of Pulse-jet Bag Filter

Bag filter, with less energy consumption, reliable operation and high efficiency to collect PM2.5,has been widely used in different industry?Pulse-jet system is the key technology of the bag filter, and reasonable design of the pulse-jet system is the basis for stable and economic operation of the bag filter? The cleaning performance,with complicated mechanism, is the result of multi-parameter coupling?The design of pulse jet system is always to rely on experiences for now?The accidents of bag breaking and clogging due to excessive and incompletely cleaning still exist in the practical application of the bag filter?Therefore, exploring the influence factor and optimizing the pulse jet system is constructive for efficient and stable operation of the bag filter?In this article, the pulse jet system and the vibration characteristics of the bag were optimized and analyzed to obtain the optimal cleaning performance and the acceleration,through the methods of computational fluid dynamics (CFD),response surface method (RSM), genetic algorithm (GA ),Latin Hypercube Design (LHD),flow-solid coupling?The specific research contents and achievements are as follows:(1) According to the characteristic of cleaning air flow and the bag structure,the simulation models of the flow field of the bag filter and the vibration performance of the bag were set up ?(2) An optimization method to raise the peak pulse pressure at the bottom and restrict maximum peak pulse pressure of the bag to improve the dust-cleaning performance of the pulse-jet system is presented. It is based on computational fluid dynamics (CFD),response surface method (RSM) and genetic algorithm (GA)?Firstly, a three-dimensional, compressible and unsteady flow mathematical model based on CFD was established?By comparing with experimental results, the reliability of numerical simulation results was verified?Then second-order response surface models of the optimization objective and the constraint were established in the design space by the Latin Hypercube Design (LHD )? Finally,the global optimal solution within the space which is based on response surface models was got by genetic optimization design?The method can greatly effectively raise the peak pulse pressure at the bottom and restrict maximum peak pulse pressure of the bag, so as to improve the dust-cleaning performance and avoid the excessive local cleaning?(3) The influence of pulse jet pressure, nozzle radius, pulse duration, filter bag length to the acceleration of the bag was analyzed: ?In the axial direction of the bag,the peak pressure rise rapidly and then decreases gradually; The maximum reverse acceleration increases rapidly and then decrease rapidly, the value in the middle and bottom of the bag is much lower than that in upper section of the bag??The cleaning mechanism in the upper section is the inertia, the maximum reverse acceleration cannot completely measure the cleaning effect??Increasing pulse jet pressure and nozzle radius raise the peak pressure, resulting in the maximum reverse acceleration of the upper section of the bag increased, which helps to improve the cleaning efficiency of the upper section; The maximum reverse acceleration at the bottom of the bag is insensitive to pulse jet pressure and nozzle radius??Pulse duration merely reflect the cleaning intensity, however the pulse duration have a positive impact on the sedimentation process of the dust, the increase of the pulse duration reduces the secondary adhesion probability of the stripping dust,which improves the cleaning efficiency?? With the length of the bag increasing,the peak pressure at the bottom is significantly reduced, but the maximum reverse acceleration decreases indistinctively?...