Sedimentation tank scraper

Sedimentation tank scraper

Overview
Concentration is a method of reducing the volume of sludge. In the process of sludge treatment, gravity concentration is generally used as a pretreatment for sludge dewatering. Therefore, the sludge concentration in the concentration tank is actually very similar to the sedimentation process in the sedimentation tank. The diameter of the concentration tank is small, often within the range of 6-20m, and the thickening machine mostly adopts a central transmission form. It is widely used for the concentration of activated sludge in industries such as municipal, light industry, mining, smelting, and steel.

Sedimentation tank scraper

The slurry or sewage containing fine-grained objects is fed into the central part of the concentration tank through a trough or sludge pipe. The slurry flows slowly and uniformly in a radial pattern towards the periphery, and the solid particles in the slurry or sewage settle by their own weight or flocculation during warm swimming. At the beginning, due to the low concentration, the particles basically settle freely with a faster settling speed, and then sink into the concentration zone with a slower settling speed. Then it sinks to a sedimentary zone at the bottom, which is also a high concentration compression zone, where water continuously precipitates from the gaps between the settling particles. When the middle rake rotates continuously, the rake teeth push the sediment along the conical slope of the pool bottom step by step towards the center of the pool bottom, and then discharge it from the discharge port at that location. When the middle rake teeth push the sediment, it is also a compression process of the scraper on the sediment, which greatly enhances the water separation effect. Therefore, the sediment discharged from the discharge port is concentrated slurry or sludge. The upper part of the pool is a clarification zone, and the clarified water is discharged from the overflow weir at the edge of the pool, thus forming the entire process of the concentrator's operation.

purpose
Suspended center drive scraper is suitable for sludge scraping and removal in radial flow (circular) sedimentation tanks with a diameter generally not exceeding 20m in water plants or sewage treatment plants in water supply and drainage engineering.
feature
1. Simple and easy to maintain and manage.
2. Smooth operation and reliable work.
3. The scraping effect of sludge is good, and the moisture content of discharged sludge is low.
4. The scraper is equipped with an up and down adjustment device, which can adjust the distance between the scraper plate and the pool body at any time.
Structure and working principle
The suspended center drive mud scraper is mainly composed of a deceleration drive mechanism, a transmission shaft, a scraper arm, underwater bearings, and a mud collecting groove scraper. The load of the entire mud scraper is applied to the center of the fixed working bridge spanning the pool diameter.
After being distributed by the central stabilizing cylinder, the raw water flows radially towards the overflow tank around the pool. As the flow rate decreases, suspended solids in the water are separated and settle at the bottom of the pool. Through deceleration driving and the transmission of suspended components, the sludge is scraped into the central collection tank by a scraper, and then discharged outside the pool by static water pressure or pump.