The Design And Optimization Of Gasifier In The Municipal Sewage Sludge Gasification Technology

Once the sludge enters the gasifier, it would undergo drying, pyrolysis, gasification and combustion processes. Chemical reactions involved in the various stages of the gasification were analyzed and the establishment of minimum Gibbs free energy of thermodynamic equilibrium model sludge gasification simulation gasification model is to provide data to the preliminary design of the gasifier. Fluidization parameter calculation, and then based on the mutual relations of the various design parameters of the gasifier the gasifier design methods; At last we design a small scale gasification experiments, and finally the experimental results with the model were compared.Here give a broad overview of the general design process:the gasifier design began in the gasifier power Q and an exit velocity can be calculated by the rated power and synthesis gas calorific value. Then gasifier efficiency and LHV of fuel can determine the feeding speed Mf, combined to the feeding amount and the equivalence ratio ER can calculate the amount of air, and then combine fluidization operating speed calculated by the correction of temperature uo, can calculate the bed diameter D, finally, calculate the bed height and determine board size distribution of the feed point location, inlet and outlet of the mouth and feed inlet parameters.Gasification experiment has three parts. At first, industrial and elemental analyzes of sludge, and were studied by TGA experiments on the material properties of the sludge. Then conducted a cold test, with the experimental results and calculation determine the parameters of the gasification experiments. At last, when change the temperatures (650oC C,675oC,700oC C,725oC C,750oC), ventilation (0.16m3/h,0.20m3/h,0.24m3/h) and particle sizes (450μm,1000μm),we observed the influence on gas composition. The results show that700oC get the best gasification result, and the gasification efficiency and the calorific value of gas production is highest. Small particle size of sludge is better for gasification; the amount of air can greatly influence the result of gasification.