In response to the call of the national sludge reduction, many industrial and municipal sewage treatment stations have replaced belt mud presses, centrifuges, spiral folding machines, and replaced them with high-pressure diaphragm plate and frame filter presses, plate and frame filter presses, and ultra-high pressure plate and frame filter presses. Many customers believe that the mud pressed out after the replacement of the plate and frame filter press has a high water content and can not even form a sandwich mud. Or the use of many different drugs can not reduce the water content.

Plate and frame filter press Plate and frame filter press the reason for the high moisture content of the mud:

1. direct feed, no need to add sludge dehydrating agent.

2. there are many hydrophilic groups on the surface of the sludge, which can not effectively release excess water.

3. the sludge and sludge dehydrating agent is not mixed enough, stirring is not uniform.

4. low solid content of sludge before filtration. The reason for the high water content of the sludge pressed by the plate and frame filter press is analyzed that the sludge does not add the sludge conditioner, and the sludge itself will form a large flocculant, especially the biochemical sludge. Biochemical sludge, a large flocculant, enters the plate and frame filter press and soon blocks the holes in the filter cloth, causing water to be unable to pass through the holes in the filter cloth.

In this case, the pressed mud will certainly have a high water content. This can also happen if there is no sludge dehydrator. Clogging filter cloth not only the mud press efficiency is slow, but also the filter cloth is easy to block manpower and time to clean the filter cloth. There are more hydrophilic groups on the surface of the sludge, and the excess water can not be effectively released. If these hydrophilic groups do not damage them, the mud surface will carry water into the plate and frame filter press. It is difficult to release the water when pressing the plate and frame filter. The presence of water absorbent groups will affect the efficiency of mud pressing and the water content of the extruded sludge. Before sludge compaction, it is necessary to add the appropriate type of sludge dehydrating agent to the sludge to effectively shed the surface EPS of the sludge, change the surface structure of the sludge, improve the sludge desliming efficiency, and reduce the water content of the sludge.

The sludge and the sludge dehydrating agent are not mixed sufficiently, stirring is not uniform, the sludge dehydrating agent is added to the sludge, the stirring time is not enough or the treatment method is not correct, resulting in the sludge dehydrating agent and the sludge is not completely mixed, the sludge surface structure is good, the filter water and the particle stiffness are correspondingly increased, and the sludge itself is poor flocculation will block the filter cloth hole. Therefore, before the sludge dewatering, the sludge dehydrating agent should be fully mixed with the sludge. Low solid content of sludge before filtration because the filtration speed of the plate and frame filter press is constant, that is to say, the speed of the plate and frame filter press per hour is certain. If the solids content is low, it means more water. If there is more water, the feed rate will slow down, affecting the efficiency of mud pressing. Because the plate and frame filter press squeezes the mud in the plate and frame by applying pressure to the plate and frame, the more mud, the lower the water content of the extrusion.