| In recent years, with the rapid development of our industry and the acceleration of urbanization, sewage continued to increase, while the sludge that as a byproduct of sewage treatment, which has the characteristics of difficult migration, easy enrichment, hazardous and other, and is very easy to cause pollution to groundwater and pollute soil. Therefore, it is one of the wide attention topics of the environmental community in our country and the whole world to how to deal with the huge amount of sludge after the scientific process.In view of reality of the co-disposal sludge in the coal-fired power plant, it is a realistic option that drying sludge to available range by using sludge drying machine, and then use circulating fluidized bed boiler mixed burnin g dried sludge. On this basis, this paper carried out the following three research areas:Firstly, make research on combustion properties of industrial sludge and coal at different sizes, different moisture content through integrated thermal analyzer by using a single variable principle, studying the combustion of mixed samples of sludge and coal through TG and DTG curves to determine combustion parameters, and get access to effects to sludge and coal mixed burning of different factors.Secondly, to study the drying characteristics of industrial sludge in a large paddle sludge drier by changing the dryer operating parameters, conducted drying performance test of industrial sludge using paddle dryer, and the results show that the optimum operating parameters of paddle sludge drier is that the feeder frequency is 45 Hz and blade shaft frequency is 25 Hz, and the drier has a higher drying rate and thermal efficiency is over 80% during the experiment, besides the surplus is about 883,800 yuan per year; The error of heat transfer coefficient is less than 20%, which is calculated with heat particle transfer model and the experimental data and heat transfer coefficient correlation is (?); Meanwhile it is also useful to take measures on the dryer to improve the system thermal efficiency, automation and dried sludge production dryer like grinding blades, installing control valve, increasing the power of the wind turbine.Finally, carrying out numerical simulation of mixed burning of sludge and coal in a circulating fluidized bed boiler by application of FLUENT software to make study on combustion characteristics of coal, urban sludge and industrial sludge at different blending ratio. The results show that: urban sludge and industrial sludge have a similar combustion characteristics, and high temperature concentrated in the dense phase region of boiler, and the furnace average temperature and carbon dioxide concentrations is decreased with the increase of sludge blending ratio, but concentration of oxygen is gradually increased, while the degree of combustion in chamber and intensity of flame fullness is worse. When blending ratio reached to 30% and 60%, combustion in the furnace is not normal; and with the increase in the proportion of sludge, the trajectories of large particles fuels is increasingly chaotic, and the particles gradually shift to the right.Coal-fired power plant co-disposal of sludge has obvious advantages, which can effectively achieve sludge stabilization, recycling and harmless. The research on the applications of industrial sludge drying and resource utilization, hoping to provide important scientific reference data for the application of sludge drying incineration technology in the coal-fired power plants. |
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