Product Information
Sludge thickening and dewatering equipment is core equipment for sludge reduction in wastewater treatment plants. The gravity sludge thickener mainly relies on gravity settling to remove free water from dilute sludge, increasing the feed concentration and reducing the load on downstream processes. The centrifugal sludge dewatering machine uses high-speed rotation to generate centrifugal force, separating the sludge and water completely with high dewatering efficiency and a very small footprint. These two types of equipment can be used independently or combined into an integrated thickening and dewatering system to meet the sludge treatment needs of plants of different scales.
Get a QuoteSludge Thickening and Dewatering Equipment | Gravity Sludge Thickener | Centrifugal Sludge Dewatering Machine
Working Principle
The gravity sludge thickener is typically a circular or rectangular tank. Sludge enters from the center and, under the action of a very slow-moving rake, solid particles settle to the bottom, and the supernatant overflows from the periphery. The thickened sludge at the bottom is collected by a scraper and pumped out. The centrifugal sludge dewatering machine has a high-speed rotating bowl and a screw conveyor inside. The speed difference causes the sludge to deposit on the inner wall of the bowl and be pushed by the screw to the conical end for extrusion, while the clear water flows back from the other end.
Application Fields
1.Municipal plants: thickening and dewatering of primary and secondary excess sludge in large wastewater treatment plants.
2.Chemical and pharmaceutical: treating chemical sludge containing fine suspended solids or colloidal substances.
3.Food processing: dewatering high-organic sludge from slaughterhouses and breweries.
4.Papermaking and printing: recovering papermaking fibers and treating printing/dyeing biological sludge.
FAQ
Q1: Can gravity thickening and centrifugal dewatering be used together?
A: Yes. Many plants use a "gravity thickening + centrifugal dewatering" process. First, a gravity thickener reduces the dilute sludge from 99% moisture down to about 95%, shrinking the volume. Then, it goes into the centrifuge for mechanical dewatering. This significantly reduces the centrifuge's processing load and chemical consumption, lowering overall operating costs.
Q2: Does a centrifugal sludge dewatering machine need flocculant?
A: Generally, yes. Although the centrifuge uses physical centrifugal force to dewater, polyacrylamide (PAM) is usually dosed before the feed to improve separation efficiency. The dosage is lower than that of a belt filter press, but you need to consider that high rotation speeds can break down the floc structure.
Q3: What are the common problems in a gravity thickener?
A: The most common issues are sludge bulking and scum. If sludge stays in the tank too long, denitrification or anaerobic reactions can occur, generating gas that floats the sludge to the surface. The solution is to control the sludge retention time or install a scum removal device. Also, when the feed load fluctuates wildly, solids can wash out, so the sludge discharge cycle needs adjustment.