A low-temperature pyrolysis system and method for domestic waste

Abstract

The invention discloses a low-temperature pyrolysis system and method for household garbage, and relates to the technical field of reduction, harmless treatment and resource recycling of household garbage. The low-temperature pyrolysis system comprises a double-shaft crusher, a belt drier, a pyrolysis device, a material separating device, a black charcoal collecting device, a storage bin, a bucket elevator, a heat-exchange lifting device, a star discharger, a pyrolysis gas purifying device, an indirect hot blast stove, a nitrogen generating device, a nitrogen circulating fan, a smoke purifying and deodorizing device, a cooler I and a cooler II, wherein all the components are connected. According to the low-temperature pyrolysis system and method for household garbage, garbage pyrolysis is completed by utilizing mass transfer and heat transfer of high-temperature quartz sand so that materials can be uniformized and a stable temperature field can be ensured, and the temperature range of garbage pyrolysis is stabilized at 450-480 DEG C. The process route comprises two sets of cyclic utilization systems which are the nitrogen circulation utilization system and the quartz sand circulation utilization system, so that raw materials are saved, heat loss is lowered to the maximum extent, and the system energy utilization rate is increased.

Description

technical field [0001] The invention relates to the technical fields of domestic waste reduction, harmless treatment and resource recycling, and specifically relates to a low-temperature pyrolysis system and method for domestic waste. Background technique [0002] Over the years, my country's garbage stockpile has reached 8 billion tons, occupying more than 500 million square meters of arable land. At present, the amount of garbage generated is still growing at a rate of 8%-10%, and more than one-third of the cities in the country are surrounded by garbage. As of 2015, 246 large and medium-sized cities across the country produced 180 million tons of domestic waste throughout the year. According to the "Thirteenth Five-Year" Ecological Environmental Protection Plan issued by the State Council, it is necessary to comprehensively improve the level of reduction, recycling and harmlessness of urban domestic waste. The treatment rate reaches over 95%. In the past ten years, the...

AI Technical Summary

Problems solved by technology

The temperature of the high-temperature flue gas is between 500°C and 1200°C, and the temperature of the pyrolysis reaction is controlled between 300°C and 800°C. The pyrolysis kettle is heated unevenly in a short period of time, and the temperature span of the flue gas in this process is large, which will aggravate the influence of uneven heating

Further, after indirect heat transfer, the pyrolysis reaction temperature is in the range of 300°C-800°C. Similarly, this range has a large temperature span, spanning the low-temperature and medium-high temperature regions of the pyrolysis reaction. The composition of domestic waste is complex, and its products are affected by temperature. The impact is very large. Different temperature ranges have great differences in the form and composition of the product. If the temperature range of the pyrolysis reaction is too large, it will affect the type and quality of the target product.

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