Dissolved air flotation deviceThe process mainly consists of three parts, namely the pressure dissolved gas system, dissolved gas release system, and air flotation separation system.

1. Pressure dissolved gas system.

It includes water pumps, air compressors, pressure dissolved gas tanks, and other ancillary equipment. The pressure dissolved gas tank is a key equipment that affects the gas dissolution effect. Adopt air compressor gas supply method. The air flotation method requires a small amount of air, so a low-power air compressor can be selected and operated intermittently. In addition, the air compressor can also ensure that the pressure of the water pump does not suffer significant damage. The pressure from the water pump to the dissolved gas tank is generally about 0.5 MPa, which can save energy consumption.

2. Dissolved gas release system.

It is generally composed of a release device (or perforated tube, pressure reducing valve) and a dissolved water pipeline. The function of the dissolved gas release device is to release the gas dissolved in water in the form of microbubbles through energy dissipation and pressure reduction, and to quickly and uniformly adhere to impurities in the water.

3. Air flotation separation system.

It can generally be divided into three types: horizontal flow, vertical flow, and comprehensive flow. Its function is to ensure a certain volume and surface area of the pool, so that the microbubble group can fully mix, contact, and adhere with the water floc, to ensure the separation of the aerated floc from the clean water.

Working principle explanation of dissolved air flotation device:

The air sent from the air compressor to the air tank is brought into the dissolved air tank through the jet device, and is forcibly dissolved in water at a pressure of 0.35 Mpa, forming dissolved air water, which is sent to the air flotation tank. In the case of sudden release, air dissolved in water precipitates, forming a large number of microbubbles that fully contact the suspended solids in the sewage that is being flocculated after being pumped and treated with chemicals. During the slow rise process, they adsorb onto the flocculated suspended solids, causing their density to decrease and float to the surface, achieving the goal of removing SS and CODcr.

Process description of dissolved air flotation device:

The water pump self regulating tank lifts the raw water to the reaction tank. The flocculant is added to the suction pipe (before the pump) and mixed with the impeller in the reaction tank for flocculation. The strength and reaction time of the reaction tank should be adjusted according to the different properties of the wastewater. After the reaction, the flocculated water enters the contact zone of the air flotation tank and mixes with the dissolved air phase released from the dissolved air release device. At this time, the flocs and microbubbles in the water collide and adhere to each other, forming gas carrying flocs that float up and undergo solid-liquid separation in the separation zone. The sludge that floats to the water surface is scraped by the scraper to the slag discharge tank and discharged. Clear water is collected by perforated water collection pipes and flows out from the collection tank. Part of the clean water is pressurized by the reflux pump and enters the dissolved air tank, where it comes into contact with compressed air from the air compressor to dissolve. Saturated dissolved water is transported from the bottom of the tank to the release device through pipelines.