Three Types of Sludge Treatment Equipments (1)

1. Current Situation of Sludge Treatment in China

With the development of urban economy, the pollution of water environment and air environment is becoming more and more serious, so the effective pollution control is becoming more and more urgent. According to statistics, the amount of sludge (dry weight) discharged by urban sewage treatment plants in China is about 1.8 million tons per year, and the annual growth rate is greater than 15%. If all urban sewage is treated, 9.3 million tons of sludge (dry weight) will be generated, accounting for 3.6% of China's total solid waste. In several cities and regions with a high level of urbanization in China, due to financial and technical reasons, the problem of sludge treatment and disposal has become very prominent.

There are three types of sludge treatment equipments mainly used in China.

2. Multi-disc Screw Press Dehydrator

2.1 Working Principle

After the sludge is sent into the screw press, it will be pushed to the discharge port by the spiral shaft. As the pitch between the fixed rings and moving rings gradually decreases, the pressure on the sludge also increases, and then the sludge will be dewatered. The water flows out from the filter gap between fixed rings and moving rings. At the same time, due to its self-cleaning structure, it will clean the filter gap to prevent blockage. After sufficient dewatering, the mud cake will be discharged by the spiral shaft.

2.2 Technical Advantages

(1) It can not only process high-concentration sludge, but also can concentrate and dewater low-concentration sludge. It is applicable to a wide range of sludge concentrations, up to 3000mg/L~50000mg/L.

(2) Under the rotation of the spiral shaft, the moving rings will continuously move relative to the fixed rings, thereby realizing a continuous self-cleaning process and avoiding blockage. Therefore, it has strong anti-oil ability, is not easy to block. In addition, there is no need for high-pressure washing, which is clean and environmentally friendly. There is no odor and no secondary pollution.

(3) The dehydrator can directly process the sludge in the aeration tank and the secondary sedimentation tank, without sludge thickening tank, thus reducing the overall investment cost, avoiding the problem of phosphorus release in the traditional sludge thickening tank, and improving the dephosphorization function of the sewage treatment system.

2.3 Applicable Industries

Industries such as petrochemical, papermaking, starch protein, chemical pharmaceuticals, blue algae, inorganic materials, etc.