Instructions for using dissolved air flotation machine

I.Purpose

In recent years, air flotation technology has been widely used in water supply and drainage as well as wastewater treatment. It can effectively remove light flocs that are difficult to precipitate in wastewater.The YW series dissolved air flotation machine is mainly used for solid-liquid or liquid-liquid separation. By using containers and release systems, a large number of fine bubbles are generated in water, which adhere to solid or liquid particles in the wastewater with a density close to that of water, resulting in a state where the overall density is lower than that of water. They are then lifted to the surface by buoyancy, thereby achieving solid-liquid or liquid-liquid separation.

II Characteristic

 1. Large processing capacity, high efficiency, and small footprint.

2. The process and equipment structure are simple, easy to use and maintain.

3. It can eliminate sludge swelling.

4. Aeration into the water during air flotation has a significant effect on removing surface activity and odors from the water. At the same time, aeration increases dissolved oxygen in the water, providing favorable conditions for subsequent treatment.

5. For water sources with low temperature, low turbidity, and high algae content, air flotation can achieve the best results.

III. Working principle

 The pollutants in sewage are divided into dissolved organic matter and insoluble substances (SS). Dissolved organic matter can be converted into insoluble substances under certain conditions. One of the methods of sewage treatment is to add coagulants and flocculants to convert most of the dissolved organic matter into insoluble substances, and then remove all or most of the insoluble substances (SS) to achieve the purpose of purifying sewage. The main method of removing SS is to use air flotation.

After the chemical addition reaction, the sewage enters the mixing zone of air flotation and comes into contact with the released dissolved air water, causing the flocs to adhere to fine bubbles, and then enters the air flotation. Under the action of buoyancy, flocs float towards the water surface to form floating slag. The lower layer of clean water flows through the collector to the clean water tank, and a part of it flows back to a certain thickness before being scraped into the sludge tank of the air flotation machine by the scraper and discharged.

IV、When using a dissolved air flotation machine, the following issues should be noted:

Equipment inspection

Before starting, carefully check whether the connection of each component of the equipment is tight, such as whether the pipeline interface is well sealed to prevent water and air leakage. At the same time, check whether the valve opening and closing status is correct.

Regularly check the pressure of the gas dissolution tank to ensure that it is within the normal range, usually around 0.3-0.5MPa, to avoid excessive or insufficient pressure affecting the gas dissolution effect.

Check if the release device is clogged, as impurities in the water may cause it to clog and affect the release of microbubbles.

Water quality and chemicals

The quality of sewage can affect the effectiveness of air flotation. If the pH of the incoming water is not within the appropriate range, for example, for some wastewater containing metal ions, an inappropriate pH may cause the metal ions to not form floc precipitates well, and pH needs to be adjusted in advance.

Accurately control the dosage of coagulants and other agents based on the composition and concentration of the wastewater. Insufficient dosage and insufficient formation of flocs; Excessive dosage not only wastes chemicals, but may also lead to deterioration of water quality.

Operating parameters

Pay attention to controlling the reflux ratio of dissolved air water, which is generally between 30% and 50%. This will affect the air flotation effect and operating costs.

According to the pollutants in the sewage, adjust the air flotation time reasonably, usually around 15-30 minutes, to ensure that suspended solids and other impurities can be fully floated and separated.

Safety and Maintenance

Because the equipment involves electrical and mechanical components, it is necessary to have good grounding to prevent electric shock accidents.

Regularly clean the equipment to remove dirt, sediment, etc. from the surface and interior, especially the air flotation tank and dissolved gas tank.

Regularly maintain key components of the equipment, such as air compressors and foam blowers, and replace worn parts to extend the service life of the equipment.