Method for drying municipal sewage sludge and anaerobic biogas residue of food waste

Abstract

The invention provides a method for drying municipal sewage sludge and anaerobic biogas residue of food waste. The two-step drying method is used to treat the sewage plant sludge and the anaerobic biogas residue of food waste. A first step is to use a submicrowave low-temperature vacuum drying technology, and a second step is to use a low-temperature centrifugal drying technology; the sludge witha water content of 10-30% and a particle size of 50-2000 [mu]m is obtained; the submicrowave low-temperature vacuum drying technology has the advantages of fast heating, high drying efficiency, good drying quality and low energy consumption, which is more than eight times of a conventional drying technology, heating is uniform, the temperature difference between the inside and outside of a material is small, the drying quality is greatly improved, electromagnetic wave radiation harmful to the human body is not generated, and the method has the functions of disinfection and sterilization, whichmake the materials more safe. The low-temperature centrifugal drying technology is used, and the energy consumption is much lower than conventional heat drying; sludge sticking to the wall can be effectively prevented, and the uniform powdery product can be dried at one time, and the steps of crushing and sieving are eliminated; the sludge fineness and the water content of the discharge are adjustable, and the drying uniformity of the sludge is effectively improved; a land occupation area is small, continuous feeding and discharging is realized, and continuous production is realized.

Description

technical field [0001] The invention relates to the technical field of sludge drying, in particular to a drying method for urban sewage plant sludge and anaerobic biogas residue of dining waste. Background technique [0002] Under normal circumstances, urban sewage treatment plants can produce 5-8 tons of sludge with a water content of 80% when treating 10,000 tons of domestic sewage. Based on the calculation of 7 tons of output, the output of urban domestic sludge in my country in 2020 will be 43.82 million tons , and grow at a rate of more than 8% every year. At present, the sludge treatment methods in my country mainly include drying + incineration, sanitary landfill, aerobic composting, and anaerobic fermentation. Anaerobic fermentation and aerobic composting have small processing scale, large footprint, and low reduction degree. Due to technical limitations, deep dehydration + sanitary landfill is the main method at this stage. With the development of the country, land r...

AI Technical Summary

Problems solved by technology

These drying methods have defects such as high energy consumption, low efficiency, and high operating costs, and cannot be widely used.

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