Vertical flow dissolved air floatation machine is a type of dissolved air floatation machine, which is a commonly used solid-liquid separation device in sewage treatment equipment, and can effectively remove suspended solids, grease, and colloidal substances in sewage. Although the working principle of the vertical flow dissolved air flotation sedimentation machine is basically the same as that of other air flotation devices, there has been significant structural reform.
Equipment usage:
In recent years, air flotation technology has been widely used in water supply and drainage and wastewater treatment, which can effectively remove light floating flocs that are difficult to settle in wastewater. Dissolved air floatation machines are widely used for sewage treatment in petroleum, chemical industry, printing and dyeing, paper making, oil refining, leather, steel, mechanical processing, starch, food, and other industries.
working principle:
After the dosing reaction, the sewage enters the mixing zone of air flotation and mixes with the released dissolved gas to make the floc adhere to the fine bubbles, then enters the air flotation zone. Under the action of air buoyancy, the floc floats to the water surface to form scum, and then enters the air flotation zone. Under the action of air buoyancy, the floc floats to the water surface to form scum. The clean water in the lower layer flows to the clean water tank through a water collector, and a part of it flows back to be used as dissolved air water. The remaining clean water flows out through the overflow port. After the scum on the water surface of the air flotation tank accumulates to a certain thickness, it is scraped into the sludge tank of the air flotation tank by a foam scraper and discharged. The sinking SS is precipitated in the vertebral body and regularly discharged.
Main structural components:
1. Air floatation machine:
The circular steel structure is the main body and core of the water treatment machine. Inside, there are releasers, distributors, sludge pipes, outlet pipes, sludge tanks, scrapers, and transmission systems. The releaser is located in the central position of the air flotation machine and is a key component for generating micro bubbles. The dissolved water from the gas tank is fully mixed with the wastewater here, and suddenly released, causing severe agitation and vortex, forming micro bubbles with a diameter of about 20-80um, which are attached to the floccules in the wastewater, thereby reducing the rising specific gravity of the floccules. Clear water is completely separated, and a conical structure with uniform distribution path is connected to the releaser, The main function is to evenly distribute the separated clean water and sludge in the tank. The water outlet pipe is uniformly distributed in the lower part of the tank, and is connected to the upper part of the tank through a vertical pipe to overflow. The overflow outlet does not have a water level adjustment handle, which is convenient for adjusting the water level in the tank. The sludge pipe is installed at the bottom of the tank to discharge sediment. There is no sludge tank in the upper part of the tank, and there is a scraper on the tank. The scraper rotates continuously to scrape the floating sludge into the sludge tank, Automatically flows into the sludge tank.
2. Dissolved gas system
The gas dissolving system is mainly composed of a gas dissolving tank, an air storage tank, an air compressor, and a high-pressure pump. The gas dissolving tank is a key part of the system, whose role is to achieve full contact between water and air and accelerate air dissolution. It is a closed pressure resistant steel tank with baffles and spacers designed inside, which can accelerate the dispersion and mass transfer process of gas and water, and improve the efficiency of gas dissolution.
3. Reagent tank:
Steel round tanks are used for dissolving and storing pharmaceutical liquids. Two of them are dissolution tanks with mixing devices, and the other two are pharmaceutical storage tanks. The volume depends on the processing capacity.
Technological process:
The wastewater flows through the grid to block the suspended solids with a large volume and enters the sedimentation tank, where different types of wastewater are mixed, homogenized, and heavy impurities are precipitated, preventing fluctuations in water quality and ensuring the stable operation of wastewater treatment. As the wastewater in the sedimentation tank contains a certain amount of lost fibers, which are the main source of wastewater SS, it is not only recycled fibers through microfiltration, At the same time, it greatly reduces the suspended solids in the wastewater, reducing a significant treatment load for the next process of wastewater air flotation. Adding coagulant PAC to the conditioning tank allows the wastewater to be preliminarily separated, flocculated, and precipitated, and then sent to the air flotation machine through a sewage pump. Under the action of flocculant PAM, a larger volume of flocculent is formed,. Due to the capture of a large number of microbubbles and the significant decrease in the specific gravity of the flocs, the clear water continues to float upward. It is thoroughly separated and flows away from the overflow port into an aerobic fast filter tank, where the clear water is further oxygenated and filtered through filter media to remove color and some sediment. After that, the clear water enters the sedimentation and clarification tank, where it is settled and clarified, and flows to the storage tank for reuse or discharge.
The sludge that floats up to the top in the air flotation machine is scraped into the sludge tank by a scraper and flows automatically to the sludge drying tank. The sludge is pumped into the sludge filter press for pressure filtration, forming a filter cake, which is transported out for landfill or burned with coal. The filtered sewage flows back to the sedimentation tank. If we continue to invest in a cardboard machine, sludge can also be directly used to produce high-grade cardboard, not only eliminating secondary pollution, but also creating significant economic benefits.
Equipment features:
1. Compared with other structures, it is integrated, with large processing capacity, high efficiency, and less land occupation.
2. The process and equipment structure are simple, easy to use and maintain. As long as the inlet and outlet pipes are connected, they can be put into use immediately, and no foundation is required.
3. It can eliminate sludge bulking.
4. Aeration into the water during air flotation has a significant effect on removing surfactants and odors from the water. At the same time, aeration increases the dissolved oxygen in the water, providing favorable conditions for subsequent treatment.
5. For water sources with low temperature, low turbidity, and abundant algae, using air flotation can achieve better results.
Post time: Mar-31-2023