In the dissolved air flotation process,Air flotation release deviceIt is a core component that rapidly releases high-pressure dissolved water under normal pressure, forming a large number of micrometer sized bubbles that adhere to the surface of suspended particles or oil droplets, promoting their upward separation. Among them, working pressure and dissolved air water reflux ratio are two key operating parameters, which do not act independently but have a significant coupling relationship, jointly determining the quality of bubble generation and overall air flotation efficiency.

The work pressure directly affects the gas solubility. According to Henry's Law, the solubility of gas in water is directly proportional to pressure. Usually, the working pressure of DAF systems is controlled between 0.3-0.6 MPa. Low pressure (such as<0.25 MPa), insufficient gas solubility, resulting in fewer bubbles and larger particle sizes, making it difficult to effectively adhere to small pollutants; Although high pressure (>0.7 MPa) can increase the dissolved air volume, it can easily cause an increase in energy consumption and may lead to bubble coalescence due to rapid release, which in turn reduces the air flotation efficiency.

The reflux ratio of dissolved water (i.e. the percentage of dissolved water to the total amount of treatment) determines the number of available microbubbles per unit volume of wastewater. The conventional reflux ratio is 10% -30%. The reflux ratio is too small, the bubble density is insufficient, and the removal rate decreases; If it is too large, it will dilute the concentration of raw water, increase the load on the water pump, and may disturb the already formed floating slag layer.

More importantly, there is a collaborative optimization window between the two. For example, at lower pressures (0.3 MPa), it is necessary to increase the reflux ratio (such as 25% -30%) to compensate for insufficient dissolved gas; At higher pressures (0.5 MPa), the reflux ratio can be appropriately reduced (15% -20%) to ensure sufficient microbubbles and save energy consumption. Experimental studies have shown that when the working pressure is 0.45 MPa and the reflux ratio is 20%, the oil removal rate of oily wastewater can reach over 92%, the effluent turbidity is below 5 NTU, and the average bubble size is stable at 20-50 μ m, achieving a balance between high efficiency and energy saving.

In addition, the structure of the release device (such as aperture and diffusion angle) can also affect the actual performance of this coupling relationship, and parameter matching needs to be carried out in conjunction with specific equipment.

In conclusion,Air flotation release deviceThe working pressure and the ratio of dissolved gas to water reflux need to be jointly regulated through systematic experiments or intelligent control strategies to avoid suboptimal operation caused by single parameter optimization. In the future, by combining online water quality monitoring and adaptive feedback systems, it is expected to achieve better dynamic control of DAF processes, improving water treatment efficiency and sustainability.