The dissolved air pump air floatation technology is a new type floatation technology developed in recent years, which has a broad market prospect. This technology overcomes the disadvantages of vortex concave air flotation technology, such as the requirement for many auxiliary equipments, large energy consumption and large bubbles, and it has the characteristic of low energy consumption. Dissolved air pumps adopt vortex pumps or gas-liquid multiphase pumps. The principle is that the air and water enter the inlet of the pump housing together, and the high-speed rotating impellers cut the inhaled air into small bubbles several times. The small bubbles dissolve quickly in the high-pressure environment of the pump to form dissolved air water, and then the dissolved air water enters the air floating pool to complete the air floating process. The bubble diameter of the dissolved air pump is about 20 to 40 μm. The air can dissolve in water, and the maximum air content in dissolved air water can reach 30%. The performance of the pump is very stable when the flow rate changes and the air volume fluctuates.
The air floatation equipment of the dissolved air pump is composed of a flocculation chamber, contact chamber, separation chamber, slag scraping device, air pump, release pipe, etc. The basic principle is as follows: First, the dissolved air pump draws water as backwater to produce dissolved air-water (At this point, the dissolved air-water is filled with a large number of tiny bubbles). Then the dissolved air-water is released to the water in the contact chamber through the release pipe, and small bubbles rise slowly and attach to the impurity particles, forming a floating body with a density less than that of water. After that, the floating body floats on the water surface to form scums, which move slowly forward with the flow into the separation chamber, and then are removed by the scum scraping device. Finally, clear water is discharged through overflow regulation to complete the air floatation process.
The dissolved air system uses a gas-liquid multiphase flow pump as the reflux pump. The gas-liquid multiphase flow pump has a special impeller structure which is different from the ordinary pump, so it is very stable when the flow rate changes and the air volume fluctuates. The gas-liquid multiphase flow pump can directly suck the air and the backflow water together from the inlet pipe of the pump. The high-speed rotating multi-stage impeller cuts the inhaled air into small bubbles many times, and the small bubbles dissolve into the backflow sewage instantly after cutting in the high-pressure environment inside the pump. Then the backflow sewage is released into the milky dissolved air water through the pressure reducing valve, so that the flocculated particles float up, achieving the purpose of purification.