Vortex Aeration Floating

Overview and Application

In wastewater treatment processes, solid-liquid separation technology is a key component. For the removal of fine suspended particles with densities close to water, air floatation separation is an ultra-effective method.

JWAF is a system specifically designed for removing oil, colloidal matter, and solid suspended solids (SS) from industrial and urban wastewater. The vortex aeration flotation utilizes the principle of mechanical aeration combined with chemical flocculation to treat various types of wastewater with different water qualities. It is an ideal physical-chemical wastewater treatment equipment, featuring reasonable design, ease of operation, and cost-effective operation. It produces bubbles from air to directly remove solid suspended solids from the wastewater.

The system is primarily used for the purification and treatment of industrial wastewater in industries such as papermaking, chemicals, dyeing and printing, food, beer, and slaughterhouses.

Operating Principle: The vortex aeration machine injects "micro-bubbles" directly into the wastewater without the need for pre-aeration. Then, the diffuser impeller distributes the "micro-bubbles" evenly throughout the wastewater, ensuring the entire process is free of clogging. The vortex aeration flotation machine is mainly composed of a housing, aeration machine, sludge scraping system, etc., and does not require equipment such as pressure aeration, air compressors, and circulating pumps.

Untreated wastewater flows into a small aeration section equipped with an vortex aeration machine. As the wastewater rises, it is thoroughly mixed with the microbubbles generated by the aeration machine within the aeration section. The aeration machine transfers air from the surface to underwater through a suction pipe. The principle of the aeration machine is to create a vacuum zone in the water by the high-speed rotation of the diffuser blades at the bottom of the air conveyance pipe, allowing air above the surface to be introduced into the water through the aeration machine, filling the vacuum. Microbubbles are then formed and spiral up to the surface, with oxygen from the air dissolving into the water.

Incorporate the reagent before the aeration machine. Due to the reagent's effect, it destabilizes the colloidal particles in the water, promoting their contact and forming flocs. Utilizing the vortex swirls in the aeration chamber, it organically combines with dense small bubbles. As the flocs rise within the aeration chamber, they further aggregate into larger flocs.

Due to the imbalance in density between the gas-water mixture and the liquid, a vertical upward buoyancy is generated, lifting the SS to the water surface. During the ascent, microbubbles adhere to the SS, and upon reaching the surface, the SS is supported and maintained at the water level by these bubbles. The SS floating on the surface is intermittently cleared by a chain scraper. The scraper moves along the entire liquid surface, with the SS flowing from the inlet of the air flotation tank to the sludge discharge pipeline at the outlet. The purified wastewater then flows into the overflow trough and is directed to the biochemical treatment section.

 The open recirculation pipe extends from the aeration section along the bottom of the floatation槽. While producing microbubbles, the vortex-shaped aeration unit forms a negative pressure zone at the pool bottom with the recirculation pipe, which draws wastewater back from the bottom to the aeration area and then back to the floatation section. This process ensures approximately 40% of wastewater recirculation and that the floatation section can still operate without incoming water.

Model Features

System Advantages

Save on investment

The vortex aeration flotation process does not require pressure vessels, air compressors, or circulating pumps, thus reducing equipment investment.

The equipment occupies a small area, reducing civil engineering investment. The vortex aeration flotation equipment with a flow rate of Q=200 m3/h covers only 36.15 m2 of land.

2. Low operating costs

The system saves on electricity consumption due to the absence of pressure vessels, air compressors, and circulating pumps. The vortex aeration system with a flow rate of Q=200m3/h consumes only 5.435KW, whereas the dissolved air flotation system consumes up to 65KW.

The vortex aeration system is easy to operate, with no complex equipment, thus reducing the labor and maintenance workload, and subsequently lowering labor and maintenance costs.

3. Notable processing effects

Removal rate of oil and solid suspended substances (SS) exceeds 80%. The removal rates of BOD and COD can reach over 60%, whereas the dissolved air flotation system can only achieve around 35% removal for BOD and COD. It promotes the oxidation of sulfur compounds, reducing the sulfur content in wastewater. Using it to treat intermediate wastewater from chemical pulping can significantly reduce the scale of secondary biological treatment equipment (if waste paper is used as raw material, the wastewater produced after deinking and bleaching processes can meet standards for discharge or reuse without secondary biological treatment), and even eliminate the biological treatment process altogether, achieving discharge standards directly. This significantly reduces the overall investment costs.

4. Simple to operate

This system is easy to operate with no complex equipment; the entire system consists of just two mechanical parts, unlike the dissolved air flotation system which includes many necessary devices such as pressure vessels, air compressors, and circulating pumps.

Parameters and specifications