Dissolved air flotation equipment is a commonly used air flotation method at home and abroad. To a certain extent, it mainly uses its container tank to make air blend into water at a certain pressure, and can present its saturated state, and then effectively disperse wastewater in the air flotation tank. The pressure suddenly drops, and then the air will precipitate from the water in the form of tiny bubbles and float. The diameter of the bubbles formed by this method is only about 80 nm. The purification effect is better than that of inflated air flotation, and it can handle the suspended matter concentration of 4-5g/ L of wastewater.
To a certain extent, dissolved air flotation equipment mainly relies on its countless micro-bubbles to adhere to flocs. Therefore, the requirements for coagulation can be appropriately reduced, which can save coagulant dosage and reduce reaction time. Since air flotation relies on bubbles to hold up For flocs, the more and heavier the flocs are, the more bubbles are required. Therefore, air flotation is not suitable for high turbidity wastewater but is more suitable for low turbidity wastewater.
The gas collection device of the dissolved air flotation equipment should first be able to reliably remove the biogas accumulated in the gas chamber and maintain a normal gas-liquid interface. The gas pipe diameter should be large enough to avoid blockage due to solids in the gas entering the pipe. It is important to install an additional device to release the gas when gas blockage occurs, so as to avoid the formation of large pressure on the reactor structure, usually in the form of a water-sealed tank. Biogas contains saturated steam and hydrogen sulfide, which is corrosive to a certain extent.
Air intake method of dissolved air flotation machine
The dissolved air flotation equipment will have two air intake methods during operation, air intake before the pump and air intake after the pump. This is mainly done by leading a pipe from the water pump pressure pipe back to the water suction pipe, and installing a hydraulic injector on the branch pipe. When the wastewater passes through the hydraulic ejector, it creates negative pressure. After the air is sucked in and mixed with the wastewater, it is sent to the dissolved air tank through the water suction pipe and water pump. This method eliminates the need for an air compressor, is relatively simple, and mixes water and air evenly, but the water pump must use self-priming water inlet and maintain a water head of more than 1m. In addition, the maximum air suction volume cannot be greater than 10% of the water suction volume of the water pump. Otherwise, the water pump will work unstable and cavitation will occur.
Dissolved air flotation equipment takes air in after the pump, usually through compressed air through the pressure water pipe. This method can make the work of the water pump stable. To a certain extent, it does not need to work under positive pressure, but it needs to be supplied by an air compressor. For air, in order to ensure good gas dissolving effect, the volume of the gas dissolving tank is also relatively large, and generally a more complex filled gas dissolving tank needs to be used.
The long pin of the dissolved air flotation machine is generally used between the scraper and the connecting block. It is used to fixedly connect the scraper and can be used as a scraper and traction plastic chain. It is characterized in that the driving sprocket is fixedly installed on the upper adjustment seat. The upper adjustment seat is movably connected to the lower adjustment seat through a movable shaft. The other part of the upper adjustment seat One end is provided with an adjusting bolt, and the spherical shaft of the adjusting bolt is fixed at the corresponding position of the lower adjusting seat.
After assembling the nylon chain of the dissolved air flotation machine, be sure to install the circlip into the connecting block to prevent the long axis from detaching and the scraper slipping during use. Install the assembled nylon chain slag scraper on the dissolved air flotation machine. When adjusting the tension on the machine, be sure not to make the chain too tight, and gradually tighten it as the chain loosens during use.
