The working principle of the spiral sludge dewatering machine

The spiral sludge dewatering machine was implemented as an industry standard for sludge dewatering equipment on March 1, 2016. Its core structure consists of a fixed ring and a moving ring stacked together. Through the rotation of the screw shaft, the sludge is pushed to achieve integrated treatment of concentration and dewatering. This equipment adopts a unique self-cleaning design to prevent the filter gap from getting blocked, and can reduce the sludge moisture content to 60%-80%. It is applicable in various fields such as sewage treatment, food processing, and chemical production. As of 2024, its technology has been applied in the expansion and relocation projects of municipal sewage treatment plants, featuring low construction costs and high automation levels.

The core components of the spiral sludge dewatering machine are a filtering device composed of a fixed ring and a moving ring stacked together. The screw shaft running through it moves the sludge by rotation. Its working principle can be divided into the following three stages:

Concentration stage:

After the sludge is mixed with the flocculant and enters the spiral body, the screw shaft rotates, and under the action of gravity, the water flows out through the ring gap, and the sludge is preliminarily concentrated.

Dewatering stage:

As the screw shaft advances, the pitch and the ring gap gradually decrease, and the sludge is squeezed to release water. The back pressure plate at the outlet enhances the pressure, and finally a dry sludge cake is formed.

Self-cleaning stage:

The screw shaft drives the moving ring to move relative to the fixed ring, automatically removing the residual sludge in the ring gap to avoid blockage.