How to treat sludge by sludge drying equipment?

Low-temperature sludge drying is to use the heat pump system to cool and dehumidify the wet air from the drying cavity through the evaporator, and at the same time, to raise the temperature and reheat it through the condenser, and then to heat it into dry hot air and send it to the drying cavity. The whole process is completed below 60℃. In this way, the water in the sludge is discharged into the sewage tank through the condensed water, and the sludge with water content of 83% can be directly dried into dry sludge with water content of 10%-30%. The whole drying process is basically completed in a closed system, and almost no discharge is made.

I. Technical principles

The whole drying process is completed under the perfect cooperation of refrigerant circulation system and air circulation system. The refrigerant circulation system consists of compressor, condenser, expansion valve, evaporator, auxiliary drying filter and liquid storage tank. The pipes between them are connected in turn to form a closed system, in which the refrigerant flows continuously. The compressor compresses the refrigerant gas with lower pressure into the gas with higher pressure, then sends it to the condenser, condenses it into the liquid with higher pressure (heat release and heating process), becomes the liquid with lower pressure after throttling by the expansion valve, then sends it to the evaporator, evaporates it into the gas with lower pressure (heat absorption and refrigeration process), and then sends it to the condenser.

The air circulation system consists of blower, filter screen and heat exchanger. A closed internal circulation air duct is formed by a drying device (hopper or mesh belt), an evaporator and a condenser which are communicated in sequence: dry high-temperature air blown by a blower is heated by the drying device; After the material absorbs heat. Dry high-temperature air becomes high-temperature and humid air. Along the top air duct, through the filter screen and heat exchanger, into the evaporator; The high-temperature and moderate-humidity air becomes dry low-temperature air after being dehumidified by the evaporator, and the dry low-temperature air reaches the condenser through the heat exchanger to be heated; After heating, dry low-temperature air becomes dry high-temperature air. The negative pressure of the blower enters the drying device. Complete air circulation.

Two. Application industry

Low-temperature sludge drying is widely used in the reduction of municipal sludge and industrial sludge (printing and dyeing, electroplating, chemical industry, leather, pharmacy, paper making, grinding, etc.). ). After sludge is dried, it can be better classified and disposed: co-burning, composting, gasification or harmless resource recovery of building materials.