Sludge is a kind of solid waste generated during sewage disposal process. With the development of sewage treatment, the total volume and processing degree of the sewage plants will be improved continuously, and the yield of sludge will also be increased. Except abundant organic matter and rich nutrition like nitrogen and phosphor, there are also poisonous and harmful ingredient in the sludge such as heavy metal, pathogenic bacteria and parasites. To prevent secondary pollution caused by the sludge and ensure the normal operation and disposal effect of the sewage disposal plant, sewage and sludge disposal equipment is very important.

To avoid random release of sludge, the government has issued related measures to promote reasonable disposal of sludge.

In a sewage disposal plant, the disposal process generates 70,000m3 waste gas of 55℃ an hour, which is reduced to 20℃. During the cooling process, it generates 2 tons of condensed water per hour. And there is ammonia gas in the waste gas.

Three workshops has radiator heating and the total floor area is 3456m2（48m×72m×4.5m）. The outdoor temperature is -7℃ in the heating period in winter. In the principle of energy-saving and environmental care, we recover the heat in the waste gas and use air-to-water heat exchange to heat the water to 85℃ to meet the heating requirements, we suggest Land heat pump unit..