What is the working principle of air flotation for oil removal in residual ammonia water?

Control the air intake volume to remove light oils

The oil removed from the remaining ammonia water is tar, and clarification filtration is commonly used for this purpose.

The air flotation device is a fast and efficient solid-liquid separation technology. In recent years, it has been widely used in wastewater treatment and water supply and drainage treatment. It can replace sedimentation and clarification processes in wastewater treatment, and is particularly effective in dealing with those light flocculates that are difficult to settle, such as oil. Furthermore, due to its aeration and oxygenation process, it can remove color and odors while increasing the dissolved oxygen in water; as a result, it is more effective at removing organic substances. The air flotation device introduces air into water under pressure, allowing it to flow into the tank to be treated. Upon sudden pressure release, this air emerges in the form of tiny bubbles that serve as carriers, enabling the flocs to attach to these bubbles and rise to the surface, where they form foam scum that can be separated from the water. The types of air flotation devices can generally be divided into various forms such as jet air flotation, impeller air flotation, diffuser aeration air flotation, pressurized dissolved air flotation, and vacuum air flotation. These air flotation devices all suffer to varying degrees from issues such as low suction capacity and large bubble diameters. The high-efficiency oil removal machine developed by our company uses a specialized gas-liquid multiphase pump as the dissolved air pump. The gas is directly drawn in at the pump inlet pipe using its own vacuum. The special impeller design of the gas-liquid multiphase pump enables thorough mixing of the gas and liquid phases during pressure generation, resulting in high-pressure saturation. During decompression, the dissolved gases escape in the form of microbubbles and disperse throughout the air flotation device. The diameter of the bubbles produced in this way can be less than 30 micrometers. Depending on the properties of gases and liquids, as well as changes in temperature and pressure, the saturated solubility of gases in liquids varies. In addition to dissolved air, chlorine, carbon dioxide, and others can also be dissolved. The maximum gas content in gas-liquid multiphase pumps can reach 20%. The performance of the pump remains very stable under changes in flow rate and fluctuations in air volume, providing favorable operating conditions for pump regulation and the control of the air flotation process. Traditional air flotation devices achieve dissolved air through static pressure in a dissolved air tank, and they require a series of associated equipment such as air compressors, dissolved air tanks, water pumps, control systems, release devices, valves, etc. Since saturated dissolution of gas in water cannot be achieved, large air bubbles tend to form after decompression, which affects the efficiency of the air flotation process. Using a gas-liquid multiphase pump for dissolved air not only eliminates most of the associated equipment, reducing investment and operating costs, but also significantly improves the efficiency of air flotation treatment due to the small size and uniform dispersion of the bubbles. Compared with the gas dissolution in the pipes of a jet pump dissolving system, gas dissolution in a gas-liquid multiphase flow pump occurs during the multi-stage pressure increase process of the pump; thus, the gas solubility is easier to control, and the dissolution effect is more satisfactory. The flotation treatment efficiency using gas-liquid multiphase flow pumps is far superior to that of jet pump dissolved air systems.

4# 8438308 Ammonia-based degreasing is used to remove heavy oil. I’ve heard of this method for the first time; I’ve learned it! ! ! If ventilation is applied to ammonia solution, ammonia will also be separated out! I think ordinary coking plants use static separation. [I only know a little about coking; it might not be correct, so I hope for corrections.]