Sludge deep drying method and system based on air heat pump

Abstract

The invention discloses a sludge deep drying method and system based on an air heat pump. The method comprises the following steps: 1) adding excess sludge to be treated into a sludge pulverization and drying device, and pulverizing and crushing the sludge to be treated with a water content of 30-55% into sludge powder particles with a particle size of 30-250 [mu]m; 2) feeding dry air, mixing thedry air with sludge powder particles under a stirring condition, drying the sludge powder particles to obtain sludge dry powder, and changing the dry air into low-temperature humid air carrying the sludge dry powder; 3) carrying out gas-powder separation on the low-temperature humid air carrying the sludge dry powder through a separation device to obtain a solid substance, namely, the sludge dry powder, wherein the moisture content of the sludge dry powder is 15%-25%; 4) feeding the separated low-temperature moisture-containing air to a condensation dehumidifier for condensing water removal sothat low-humidity low-temperature air is formed; 5) feeding the low-humidity low-temperature air into an air heat pump to be heated to become dry air again for recycling, wherein heat absorbed by cooling air returns to the air heat pump and exchanges heat with the low-humidity low-temperature air. The sludge drying system has the advantages that sludge is deeply dried, environment air is directlyused as a heat source, energy is saved, and efficiency is high.

Description

technical field [0001] The invention relates to a method and system for deep drying of sludge based on an air heat pump, in particular to a method and a process system for deep dehydration of excess sludge, belonging to the subfield of treatment of excess sludge in sewage treatment plants in the field of environmental protection technology. Background technique [0002] With the development of our country's society and urbanization, the amount of urban sewage is increasing, the number of corresponding sewage treatment facilities is also increasing, and the by-product of sewage treatment - the amount of residual sludge is also increasing. . As of 2017, the annual output of surplus sludge in my country has exceeded 40 million tons, while the harmless treatment rate is less than 10%. How to properly handle and dispose of these continuously generated and increasingly large amounts of sludge has become an urgent problem to be solved in my country's environmental protection. [...

AI Technical Summary

Problems solved by technology

As of 2017, the annual output of surplus sludge in my country has exceeded 40 million tons, while the harmless treatment rate is less than 10%.

The above process can quickly remove the water in the sludge, but the degree of dehydration is limited, and it is difficult to achieve deep drying of the sludge (moisture content ≤ 20%)

Images