Description of Micro Bubble Generation Method

According to the different generation mechanism, microbubble generation technology can be divided into five categories: dispersed gas, induced gas manufacturing, micro pourous media, shear contact and electrosis.

The first two types are widely used in industrial practice, and the typical application examples are dissolved air flotation and induced air flotation. The bubble of dissolved gas is to dissolve the gas into the water under a certain pressure, then depressurize the dissolved gas water, and the dissolved gas will be released from the water in the form of microbubbles; the bubble of induced gas is to inhale the gas through the negative pressure effect produced by the venturi jet or the rotary cutting of the impeller, and further break it into microbubbles. Objectively speaking, it has the following shortcomes, for example, the system composition of conventional dissolved gas bubbles is relatively complex (compressor, packing dissolved gas tank, dissolved gas releaser, etc.), and the operation and maintenance cost is relatively high. Although the equipment for producing bubbles is relatively simple, the bubble size obtained is large and the uniformity is not high, which affects its wide application. Although the microbubble generation technology based on the gas-liquid mixing pump involves the mechanism of dissolved gas separation and shear contact foaming due to the different structure, it will make the shear emulsification more serious for the oily wastewater treatment and other occasions, but it is not conducive to the subsequent separation process. Moreover, the design and manufacturing technology of high-performance gas-liquid mixing pump has not been independently mastered in China.

With the continuous progress of material forming and manufacturing technology, microporous media materials with sufficient porosity, strength, stiffness, corrosion resistance and wear resistance are emerging. Microporous media foaming technology is increasingly concerned because of the advantages of simple system composition.

The working principle of this technology is that when the high pressure gas passes through the microporous medium layer, it is cut into a fine air flow by the microporous on it, and then the microbubbles are formed under the action of flow shear or scouring of the liquid. According to the materials of microporous media layer, corundum, rubber, high-density PE, metal powder sintering, ceramics, etc. are commonly used as materials of metallurgical powder, ceramics or plastics, and then mixed with appropriate adhesives such as phenolic resin, which are sintered at high temperature; from the shape of microporous media layer, there are round tube, flat plate, cover plate, bell cover, round arch, ball head, etc. For example, corundum microporous aerator, HDPE covered microporous aerator and rubber membrane microporous aerator used in aerobic biochemical treatment of sewage are typical microporous medium foaming technology products.