Modelling heat-and-mass transfer process and chemical reaction of gas-dispersed flow of the pulverized coal particles in high-temperature gasifier
A way to reduce consumption of expensive imported natural gas in the production of chemical products (ammonia, methanol, and other) is the use of synthesis gas, which can be obtained by steam-oxygen gasification of Alexandria dry lignite dust in a high-temperature flow of 4.2 Mpa pressure. For the construction of such devices at conceptual and technical design stages we constructed a model of the working process in the gasifier, by means of which detailed information about the geometrical, aerodynamic, thermal, chemical and physical parameters was obtained: 1) the optimum ratio B0 /BEy = 0,785 and BE^0 /B=y = 0,052 were found providing synthesis gas composition with a high content of combustible components - 93,2%, a low concentration of ballast - 2,8%, the degree of carbon conversion - 99,9% and calorific value - 11,17 MJ/Nm3; 2) as the liquid slag temperature exceeds the liquidity of ash, shotcrete is made as a double-layer (the first layer - silicon carbide mass, the second - stabilized zirconium oxide) across the height of the reactor; 3) The main sources of radiation in the maximum temperature zone are gas - 1595 kJ/(s-m2) and carbon 1161 kJ/(s-m2).
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