Belt filter press working process

1. Pretreatment stage 

The solid content of the original slurry is generally low, and the slurry concentration or other means must be used to increase the slurry concentration to reduce the treatment cost. The commonly used pretreatment method is: mixing the concentrated sludge with the high-molecular flocculant, and under the action of the flocculating agent, the micro-particles of the material are agglomerated into agglomerate and preliminarily precipitated, which is a preparation condition for the dehydration of the sludge on the machine.

2.Gravity dewatering stage

The sludge after flocculation pretreatment is added to the filter belt. Under the action of gravity, the free water outside the floc is filtered through the filter belt, which reduces the water content of the sludge.

3. Wedge pre-pressure dewatering stage 

After the gravity dewatering, the sludge begins to enter the wedge-shaped pressing section, the filter belt gap is gradually reduced, and the extrusion and shearing action is applied to the sludge to dehydrate the sludge again. After this stage, the sludge fluidity is almost completely lost, thus ensuring that under normal conditions the sludge will not be squeezed out in the press dewatering section.

4. Squeeze dewatering stage 

The sludge is repeatedly squeezed and sheared by a series of carefully designed press rolls to remove a large amount of capillary water, so that the sludge moisture is gradually reduced, forming a sludge filter cake, at the re-selection of the filter belt. The filter cake is scraped off by a discharge scraper. After unloading, the filter belt is washed and goes to the next cycle.