Experimental&Numerical Simulation Study On Dust Removal With Ceramic Filter At High Temperature

Integrated gasification combined cycle (IGCC) and pressurized fluidized bedcombined cycle (PFBC) power generation are two kinds of the most promising clean coalpower generation technology. For the two power generation technologies, it is importantthat remove the dust from gas effectively with the rigid porous ceramic filter under hightemperature and high pressure, which ensure the safety of the whole system.First, a small single-tube ceramic filter dust collector unit is designed and built, thedust removing characteristics and flow resistance characteristics are tested in theexperiment. The experiment adopts two air admission ways which are the lower verticalinlet and the upper radial inlet. When the working gas is clean, the pressure drop varylinearly with gas filtration rate, being consistent with the Darcy law, and the changeconditions of two kinds of air inlets are basically identical. While the dusty gas goes intothe filter, the dust cake will form outside the filter tubes wall, so pressure drop changeswith inlet types, dust content, working time and gas filtration velocity. Under the samegas filtration velocity, for the rates of pressure drop resistance increasing with time，therate of upper radial inlet is smaller than the rate of lower vertical inlet, so the upper radialinlet can extend the cleaning cycle. And under the same gas flow, flow resistancecoefficient of the upper radial inlet is smaller than coefficient of the lower vertical inlet.For two types of inlets, the work conditions are optimized at the same time, and itreaches the optimal working statuses of the dust removal process. When the gas pressureincreases, the permeability of gas flowing through the porous ceramic tube decreases,which is not conducive for dust removal process.Second, Gambit is used to establish model and mesh, the dust removal process issimulated by the use of Fluent software. RSM turbulence model is used for gasmovement, dust particles movements adopt discrete phase model, porous medium modelis applied to the ceramic filter tube. The dust removal process is calculated underdifferent parameters and gas inlets, the results coincide with the actual experiments.Inside the tube, the pressure value decreases and the flow velocity increases rapidly alongthe filter axial direction from bottom to top, the velocity of upper radial inlet at the exit is less than the velocity of lower vertical inlet at the exit, and the velocity fluctuation ofupper radial inlet is smaller outside the filter tube. With the increase of gas flow rate orthe decrease of particle size, the time of the dust particles being trapped in the filter willbe shorten for the lower vertical inlet, when the flow rate is larger or the particle size issmaller, the distribution of deposition particles in the vertical wall tends to be moreequispaced. For the upper vertical inlet, dust particles deposite relatively uniform underthe various flows and particle size, the deposition amount is generally less near the exit.The simulation results provide some reference value for the actual industrial applications.