| Oil and gas less, coal more-the characteristic of resource distribution, determines that our country uses coal as main resource. Coal pyrolysis at low temperature is an important way to use coal cleanly and efficiently. However, there is a bottleneck problem that the separation of high temperature pyrolysis gas and dust in the process of coal pyrolysis at low temperature to be solved.To improve the dust removal efficiency in the process of coal pyrolysis at low temperature, this paper investigates the characteristics of fine coke and coal ash in volatile and the requirements for dust collector, expounds and summarizes the research status and development of dust removal technology about gas cleaning at high temperature. Based on the granular layer dust removal technology, the paper creatively proposes high temperature liquid & fixed granular layer gas-solid separation technology, and does experimental research about the technology.A kind of high temperature liquid called HTL was made based on analyzing physical properties and chemical properties of different chemical substances. Experiment analysis was conducted to know thermal stability of HTL. The melting temperature, initial crystallization temperature and discomposed temperature of HTL is 383℃,403℃ and 780℃. Thermal stability and chemical stability of HTL are well below discomposed temperature 780℃ and its thermal stability is still well when it is heated continuously. The best application temperature is 433～780℃. Chemical reactions will not occur when HTL meet with high temperature pyrolysis gas and its components. HTL can be applied to high temperature liquid & fixed granular layer gas-solid separation technology as the high temperature liquid.Cold state experiment research on high temperature liquid & fixed granular layer gas-solid separation technology was conducted. Under laboratory conditions, dust removal efficiency is increasing with the increase of spray fluid volume when it in a certain range(less than 0.00560m3/h); when it increases to a certain value(0.00672m3/h), dust removal efficiency increases unapparently. Pressure drop is increasing and the speed of increase gradually increases with the increase of spray fluid volume. When spray fluid volume is certain, dust removal efficiency is increasing with the increase of bed height, and decreasing with the increase of filtering gas velocity. Pressure drop is increasing with the increase of bed height and filtering gas velocity. Pressure drop increases gradually and tends to be stable with the increase of filtering time.Based on cold state experiment, hot state experiment research on high temperature liquid & fixed granular layer gas-solid separation technology was conducted. HTL can be applied to high temperature liquid & fixed granular layer gas-solid separation technology. In the process of dust removal from high temperature gas, high temperature liquid & fixed granular layer gas-solid separation technology can make sure that dust removal efficiency is higher and stable. What’s more, as the high temperature liquid, HTL can be circularly applied to high temperature liquid & fixed granular layer gas-solid separation technology, so that high temperature liquid & fixed granular layer gas-solid separation technology is economical and it can make sure that dust removal efficiency is higher and stable at the same time. |
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