Vertical flow dissolved air flotation machine flotation separation technology is the air and water at a certain pressure conditions greatly limit the gas dissolved in water, and strive to be saturated, and the pressure of the dissolved gas and water formed by subtracting press release, a large amount of fine bubbles, full contact with the suspension of floc in the water, so that the water suspended floc adheres to the micro-bubbles, together with bubble float to the surface and scrape off the scum scum formation, thereby purifying water. Flotation water purification technology is widely used at home and abroad. Flotation device domestic applications have dispersed air flotation, electrolysis flotation method, pressure dissolved air flotation method (hereinafter referred to as conventional flotation method), the most widely applied pressure dissolved air flotation method. DAF is the use or partially treated water back to the water, the micro-bubble generator draws air into the mix to form a dissolved gas and water, release pressure in the flotation tanks, into the air bubbles in the water to form 20-30μm precipitation, has a high surface area and adsorption capacity for different concentrations of suspended solids in wastewater can be better removed, some water after treatment (design target of 20-40%, can usually be 30%), the flotation cycle work pump, pressure tank carried into the aqueous mixed with air, the air is dissolved into the water, then dissolved gas efficiency of more than 80%. Air dissolved in water is released from the water, forming a particle size of 20-50μm microbubbles, microbubbles suspended solids in sewage-binding, so the proportion of suspended solids in the sewage becomes small, floating on the water until the surface; forming a large number of floating slag, then by flotation pool installation chain foam blowing machine, remove the scum, to the treatment effect. First, the working principle: the air is pumped into the pressure vessel through cans at 0.5MP pressure is forced to dissolve in water, in the case of a sudden release, resulting in severe agitation and vortex formed about 20-80um diameter microbubbles so attached to the wastewater floc, thereby reducing the proportion rising floc, water thoroughly isolated. Second, the dissolved air flotation categories according to the type of suspended solids contained in waste water, nature, dealing with different degrees and pressurized water purification methods, there are three basic processes. (1) the whole process of the whole process of dissolved air flotation method dissolved air flotation process is all waste water pump pressure, before or after the pump air injection pump. In the dissolved gas cylinders, air dissolved in the water, and then the water away flotation tank through the valve. Wastewater formation of many small bubbles adhere to the wastewater suspended solids and emulsified oil or the escape of the water, forming a scum on the water. Even with a blade into the scum scum trough, the scum pipe from outside the pool, treated wastewater is discharged through the overflow weir and outlet. Advantage of the whole process of dissolved air flotation method: ① large gas dissolved, increasing the chance of contact with the oil particles or bubbles suspended particles; ② handle the same amount of water under conditions, which compared partial reflux dissolved air flotation method required gas floating pool is small, thereby reducing capital investment. But because all the water through a pressure pump, so increasing the level of emulsification of oily wastewater, and the desired pressure pump and dissolved gas cylinders compared with the other two processes large, so the investment and operation of large power consumption. (2) of the Act partially dissolved air flotation dissolved air flotation method is to take part of the waste water pressure and dissolved air, and the remaining waste water directly into the flotation tank and mixed in a dissolved air flotation tank and waste water. Its characteristics are: ① over the whole process of dissolved air flotation method desired pressure pump is small, so low power consumption; ② pressure pump caused by emulsified oil over the whole process of dissolved air flotation method is low: the size of the flotation tank and ③ the same as the whole process of dissolved air flotation method, but more partial reflux little dissolved air flotation method. (3) partial reflux dissolved air flotation method partial reflux dissolved air flotation method is to take part degreasing effluent recycle pressurized and dissolved gas, directly into the flotation tank under reduced pressure, and the oily waste water from the flocculation tank mixing and flotation . Return flow is generally 25% to 100% of oily wastewater. Its characteristics are: ① less pressurized water, power consumption province; ② flotation process is not to promote the emulsification; ③ alum formed good, the water is also less flocculation; ④ flotation tank volume over the previous two processes large. In order to improve the treatment effect flotation, often added to the wastewater coagulant or flotation agents, the dosage varies due to different water quality is generally determined by the test. Three major structural vertical flow dissolved air flotation machine consists of the following components: 1, flotation machine circular steel structure, is the main and core water treatment machines. Internal release, a uniform, a sludge pipe, outlet pipe, sludge tank, transmission and other scraper. 2, dissolved air system dissolved air system consists of dissolved gas cylinders, cylinders, air compressors, high pressure pump that, dissolved gas cylinders is the most critical part of the system, its role is to achieve full contact with water and air, to accelerate the air dissolved. It is a closed pressure steel tanks, internal baffle design, the spacer can accelerate dispersion of gas and water, the mass transfer process, improve the efficiency of dissolved air. 3, circular steel tank in tank storage of liquid used to dissolve, two of which dissolving tank with stirring device, the other two for the agent storage tanks, volume matching with the processing power and size. Features: Features four vertical flow dissolved air flotation machine with a high efficiency of dissolved air systems, micro-bubble average diameter of 1μm or less, compared with the current level of domestic and foreign 20-50ml at least reduced by 20 times, that is, when dissolved When the gas is equal to the total surface area of ??the microbubbles increased by at least 400 times. In fact, since a substantial increase in the rate of dissolved air micro-bubbles or bubble density increases the total surface area of ??thousands of times. Foreign scholars show: When the microbubble diameter of less than a certain value, according to statistical mechanics, the impact force of water molecules surrounding the thermal motion of the out of balance, the bubble will participate in part of the Brownian motion is extremely beneficial bubbles of oxygen diffusion to sewage, Thus aeration effect will far more than a thousand times higher. The machine uses a special internal stainless steel bodies, play an unprecedented rectification, steady flow effects, as well as special and efficient delivery system to maximize the elimination of dissolved gas and water energy, that makes dissolved gas from depths down to balance the energy value low energy value almost close to atmospheric pressure. The device structure is compact, small size, small footprint. The machine consumes less power than conventional flotation can be reduced by 50%. Drug consumption is low, than conventional flotation method can be reduced by 50%. Exclude dross at high concentrations, up to 4%, the water is clear and transparent, SS removal rate of more than 96%, non-soluble COD can be removed completely. Solid-liquid separation speed, small footprint, low energy consumption. Sludge moisture content is low, the operation is simple and stable and reliable operation.