Negative-pressure thermal desorption treatment system for mercury contaminated soil

Abstract

A negative pressure thermal desorption treatment system for mercury contaminated soil comprises a pretreatment device, a feeding device, a waste heat utilization heat exchanger, a negative pressure heating device, a soil collecting box and an air extractor. The pretreatment device is used for crushing soil and mixing the soil with a catalyst; the feeding device conveys the soil from the pretreatment device to the waste heat utilization heat exchanger; the waste heat utilization heat exchanger is used for preheating the soil and enabling the soil to fall into the negative pressure heating device; the negative pressure heating device is used for carrying out thermal desorption treatment on the soil and enabling the soil to fall into the soil collecting box; the air extractor extracts hot airin the negative pressure heating device to form negative pressure in the negative pressure heating device; the air extractor is connected with an air inlet of the waste heat utilization heat exchanger, hot air flows into the waste heat utilization heat exchanger to exchange heat with the soil; and an air outlet of the waste heat utilization heat exchanger is sequentially connected with a cyclonedust collector, a condensing device and a tail gas treatment device. Safe and efficient negative pressure thermal desorption treatment can be conducted on mercury-containing soil.

Description

Technical field [0001] The invention relates to the field of mercury-contaminated soil treatment, in particular to a negative pressure thermal desorption treatment system for mercury-contaminated soil. Background technique [0002] Mercury is a toxic metal, which is extremely harmful to the ecosystem and human health. In recent years, human activities have released a large amount of mercury, which has caused serious pollution to the atmosphere, water and soil around the mercury emission area. At present, how to remove mercury pollution in soil efficiently and environmentally is the concern and research of society. The thermal desorption process is one of the best technologies to treat mercury-contaminated soil. This technology uses direct or indirect heat exchange heating to bring the polluted components in the soil to a high enough temperature to evaporate and separate from the soil medium. the process of. At present, thermal desorption equipment in the form of rotary kilns a...

AI Technical Summary

Problems solved by technology

However, after this heating treatment, the nutrients in the soil will be destroyed, thereby changing the physical and chemical properties of the soil, and the energy consumption is high

In addition, the sealing of the device is poor, and it is easy to leak air in the feeding and discharging unit, which greatly reduces the mercury removal effect and easily causes secondary pollution.

Images