Product Information
A sludge scraper is common equipment for sludge removal in settling tanks. A traveling bridge sludge scraper usually moves back and forth along the top of a rectangular tank, pushing bottom sludge toward the sludge collection channel on one side while scraping surface scum toward the discharge end. A settling tank sludge scraper comes in many types—the traveling bridge is a moving-floor type, well suited for rectangular tanks. For circular tanks, center or peripheral drive types are more common. These units typically run at low speed underwater and are built sturdy enough to handle a certain amount of sediment.
Get a QuoteSludge Scraper | Traveling Bridge Sludge Scraper | Settling Tank Sludge Scraper
Working Principle
Take the traveling bridge scraper as an example. The unit spans the tracks on both sides of a rectangular settling tank and moves forward and backward driven by a motor. Scraper blades hang below the frame. On the forward stroke, the blade edges press against the tank bottom and push settled sludge toward the collection hopper at one end. On the return stroke, the blades lift up—either from water pressure or a mechanical mechanism—so they don't drag sludge back. The surface section usually has a scum baffle that pushes floating scum to the discharge pipe at the end of the tank. The whole sequence can be controlled by limit switches and a PLC for scheduled or on-demand automatic operation.
Application Fields
1.Municipal wastewater treatment: bottom sludge removal in rectangular primary and secondary clarifiers.
2.Industrial wastewater treatment: large rectangular settling tanks in steel, chemical, and printing and dyeing industries.
3.Water treatment plants: sludge cleanup in rectangular settling tanks.
4.Water reuse systems: sludge collection and discharge in upstream settling tanks.
FAQ
Q1: What is the typical traveling speed of a traveling bridge sludge scraper?
A: Usually quite slow—around 0.5–1.5 m/min. Too fast stirs up the bottom sludge, hurting settling and increasing equipment wear. The drive motor typically includes a gear reducer to ensure smooth, low-speed operation.
Q2: How does the scraper blade avoid dragging sludge back on the return stroke?
A: Two common methods. One uses a hinged blade—when pushing forward, the blade presses vertically against the sludge; on the return stroke, water resistance makes it flip up automatically. The other uses an electric or mechanical lifting mechanism that raises the blades entirely on the return trip. Either way, the blades don't touch the tank bottom on the way back.
Q3: Do the tracks for a traveling bridge scraper cause problems?
A: If the tracks aren't level or have debris on them, the bridge can go off-course or jam. Clean debris and ice off the tracks regularly, and check wheel wear and drive chain tension periodically. Limit switches are usually installed at both ends to keep the bridge on track.