Product Information
A belt filter press is a continuous dewatering unit that combines gravity drainage with mechanical squeezing. As a common belt filter press for sludge dewatering, it sandwiches the sludge between two tensioned filter belts. The sludge goes through stages of gravity drainage, wedge zone pre-compression, and high-pressure roller squeezing to force out the moisture. A continuous filter press doesn't need to stop for unloading like a plate-and-frame press; it feeds and discharges 24/7 without interruption, making it a great fit for high-volume municipal wastewater plants or industrial wastewater stations.
Get a QuoteBelt Filter Press | Belt Filter Press for Sludge Dewatering | Continuous Filter Press
Working Principle
Sludge is first mixed with flocculant and spread flat on the lower belt in the gravity drainage zone, where free water drains off naturally. It then enters the wedge zone formed by the upper and lower belts. As the gap narrows, the sludge starts to get gently squeezed. Next, the belts carry the sludge cake through a series of pressure rollers with decreasing diameters. Under the combined action of shear force and compression, capillary and adsorbed water are forced out. Finally, a scraper removes the dewatered cake, and the belts pass through high-pressure wash water before re-entering the cycle.
Application Fields
1.Municipal wastewater: continuous dewatering of biological sludge in city wastewater plants.
2.Printing and textiles: solid-liquid separation of printing/dyeing and chemical sludge.
3.Papermaking industry: fiber recovery and primary sludge dewatering from papermaking wastewater.
4.Coal washing and mining: dewatering and drying of coal slime and mineral mud.
FAQ
Q1: What material are the filter belts on a belt filter press usually made of?
A: They are typically woven from polyester (PET) or nylon (PA) monofilament. Polyester belts resist acids and bases, have high tensile strength, and suit most municipal and industrial sludge. Nylon belts offer better wear resistance, making them a good fit for materials with high sand content or strong abrasiveness. The belt's air permeability and weave pattern are selected based on the particle size of the material.
Q2: How does the feed sludge moisture content affect a belt filter press?
A: It has a big impact. If the feed is too dilute (moisture too high), the gravity drainage zone gets overloaded, solids can wash off, and flocculant consumption goes up. If it's too thick, it flows poorly and spreads unevenly. Feed moisture is generally expected to be between 95% and 98%; outside this range, adjustment is needed before it goes into the machine.
Q3: Does a continuous filter press need to wash the belts all the time?
A: Yes. To keep the belts permeable and prevent the pores from clogging, high-pressure water must continuously wash both the top and bottom of the belts. Reclaimed water or filtered water is usually used, at a pressure of 0.4–0.6 MPa. If the washing isn't thorough, the belts will clog quickly and the dewatering performance will drop off sharply.