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Studying On Pyrolysis Furnace And Pyrolysis Characteristics Of Solid Wastes

Posted on:2008-10-17Degree:DoctorType:Dissertation
Country:ChinaCandidate:X Y LiFull Text:PDF
GTID:1101360245491004Subject:Thermal Engineering
Abstract/Summary:PDF Full Text Request
With the development of the national economic level, the consumption in social life accelerated. However, what comes with the development is the increment of household solid waste (HSW) which already attained attentions from government, researcher, medium, et al. The traditional methods of household solid waste disposal may cause either the pollution to our environment, or occupy the soil and other resources., Therefore, to develop new method and technique for household solid waste disposal is impendence.Compared with other traditional disposal ways of household solid waste, the pyrolysis of HSW has many advantages, such as friendly environmental, high rate of energy exchanging and better financial benefit. It is becoming a new research domain for HSW disposal issue.The key point of this study is the practical technology and equipment of pyrolysis of HSW without sorting. According to the specific characteristics of the HSW component in the cities of China and relying on the energy that produced by itself-pyrolysis as the heat source, an equipment for the HSW pyrolysis which can deal with 5 tons of HSW was designed and erected, and all the circulation performances have been done. In this equipment, the coal is used as the heat source in the main pyrolysis furnace in the beginning section as well as the trash charcoal which was produced by the self-pyrolysis is used as the heat source in the circulation section.The auxiliary pyrolysis furnace uses the residual heat of pyrolysis gas produced by the main pyrolysis furnace as its heat source, and there is extra pyrolysis gas's output which can be used as energy source. The whole process perfectly accomplished the design idea of the energy-dissipating and the waste-minimum of the HSW pyrolysis.In the process of this pyrolysis equipment design, a fixed-bed HSW pyrolysis equipment which has the continuous work ability and with the combination between externally heated and internally heated as well as the coupling usage between the main pyrolysis furnace and the auxiliary pyrolysis furnace are in present study had been considered for the first time. And the mathematical models of the HSW pyrolysis, including the mathematical models of firebox, main pyrolysis furnace and auxiliary pyrolysis were put forwarde. Fair good simulation effect has been obtained from the analysis of the thermophysical property of mixed HSW according to the cellular medium theory. Through the comparable analysis with the theoretic study of the HSW pyrolysis, the characteristics on pyrolysis temperature, volume producing and the orderliness of the volume producing of the HSW practical equipment are available now, and it provides a reliable theoretic gist in the practical use of HSW pyrolysis technology.To the component of MSW, from a molecule point of view, and according to the data of TG/DTG curve, industrial analyses and elemental analyses, some specific analyses about the chemical reaction which might be appeared in the pyrolysis procession deeply, also came to some MSW pyrogenation theory models. From above, the biology category and the plastic category of dynamical model were built, it can be used to forecast the original components and mass changes with temperature of production in every section under anytime or any temperature, with this, the design and the circulation of a reactor equipment could be supervised and optimized.As the result shows, for the same substance, although it could be a little bit different in its component, which probably may cause the differences in the temperature and time during a pyrolysis process, but all the pyrolysis mechanism is similarly the same. The pyrolysis temperature extension and its time separation are fairly close; they can be simulated under one same pyrolysis model and come out with satisfactory result.
Keywords/Search Tags:HSW, pyrolysis, pyrolysis furnace, heat transfer model, TG analysis
PDF Full Text Request
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