Overview: The pretreated wastewater flows into the small inflated section equipped with a vortex aerator. During the ascent, the sewage is fully mixed with the microbubbles generated by the aerator, and the aerator passes the air on the surface of the air through the ventilation duct. Move to underwater. The working principle of the aerator is to use the high-speed rotation of the air diffuser at the bottom of the air conveying pipe to form a vacuum zone in the water. The air on the liquid surface is input into the water through the aerator, fills the vacuum, and the microbubbles are generated and spirally raised. On the water surface, the oxygen in the air also dissolves into the water. Due to the imbalance in density between the gas-water mixture and the liquid, a vertical upward buoyancy is generated, bringing the SS to the water surface. During the float process, microbubbles will adhere to the SS, and the SS will rely on these bubbles to support and maintain the surface after reaching the water surface. The SS floating on the water is intermittently removed by the chain scraper. The scraper moves along the entire surface and pushes the SS from the inlet end of the float tank to the sludge discharge pipe at the outlet end. There is a horizontal screw propeller in the sludge discharge pipe, and the collected sludge is sent to the mud collection tank. The purified sewage flows into the overflow tank and flows to the biochemical treatment section. An open return line extends from the aeration section along the bottom of the floatation tank. At the same time as the microbubbles are generated, the vortex aerator will form a negative pressure zone at the bottom of the tank with the return pipe. This negative pressure will cause the waste water to flow back from the bottom to the aeration zone and then back to the air float zone. This process ensures that about 40% of the sewage returns and that the floating section can still work without water.
Advantages: 1.Save investment There are no pressure vessels, air compressors, circulation pumps and other equipment in the vortex air flotation system, so the equipment investment is small. The equipment covers a small area and reduces the investment in civil construction. The footprint of the CV equipment with Q=200m3/h is only 36.15m2. 2. Low operating costs Due to the absence of pressure vessels, air compressors, circulation pumps and other equipment, this system saves electricity. The energy consumption of the QF 200m3/h CAF system is only 5.435KW, while the energy consumption of the DAF system is as high as 65KW. The CAF system is very easy to operate. There is no complicated equipment at all, so the manual operation and maintenance work is minimal, reducing labor and maintenance costs. 3. The treatment effect is remarkable The removal rate of petroleum and solid suspended solids (SS) exceeded 80%. The removal rate of BOD and COD can reach more than 60%. The dissolved air flotation (DAF) system can only remove about 35% of BOD and COD. It can promote the oxidation of sulfides and reduce the sulfur content in the sewage. 4. Easy to operate This system is very easy to operate without complex equipment; the entire system consists of only two mechanical parts, unlike the DAF system, which includes pressure vessels, air compressors, circulation pumps and many other necessary equipment. Flow Diagram:
){kind=link}