The dissolved air flotation (DAF) machine is mainly used for solid-liquid or liquid-liquid separation. Through the dissolved air and release system, a large number of fine air bubbles are generated in water. These bubbles adhere to solid or liquid particles in wastewater that have a density close to that of water, resulting in an overall density lower than water. Relying on buoyancy, the particles rise to the water surface, thereby achieving the purpose of solid-liquid or liquid-liquid separation.

Product Overview

The dissolved air flotation (DAF) machine is mainly used for solid-liquid or liquid-liquid separation. Through the dissolved air and release system, a large number of fine air bubbles are generated in water. These bubbles adhere to solid or liquid particles in wastewater that have a density close to that of water, resulting in an overall density lower than water. Relying on buoyancy, the particles rise to the water surface, thereby achieving the purpose of solid-liquid or liquid-liquid separation.

A new type of high-efficiency dissolved air equipment – the micro-bubble generator – is adopted to replace traditional air-introducing equipment for dissolving air into water. Several sets of inclined tubes are installed in the flotation area, and together with the tank body, slag scraper, and screw discharger, they form a complete flotation water purification device. Theoretically, the treatment effect of flotation has no direct connection with residence time, but is only related to the flotation area. If the depth of the flotation zone (originally H) is reduced to H/10, both the flotation distance and residence time will be reduced by 10 times. This is the well-known "shallow tank theory". The purpose of adding inclined tubes in the flotation area is to increase the flotation area, significantly reduce the Reynolds number, prevent flotation from occurring in a turbulent state, create a good laminar flow state, and achieve the effect of shallow-layer flotation.

Similarly, when the density of suspended solids is greater than 1, the installation of inclined tube sets will produce the effect of shallow tank sedimentation, allowing sedimentation to proceed under turbulent conditions. Pollutants with larger particle sizes and higher specific gravity that are not easy to float will be concentrated in the sludge collection area, achieving the goal of water purification.

According to the water flow mode, it can be divided into: horizontal-flow dissolved air flotation machine, up-flow dissolved air flotation machine, and comprehensive dissolved air flotation machine.

Application Scope

1. Separating fine suspended solids, algae, and other micro-aggregates in surface water.
2. Recovering useful substances from industrial wastewater, such as pulp in papermaking wastewater.

Winter Maintenance

The dissolved air flotation machine is suitable for treating water with low turbidity, high chroma, high organic matter content, low oil content, low surface active substance content, or water rich in algae. Compared with other flotation methods, it has advantages such as high hydraulic load and compact tank structure. However, its complex process, high electrical energy consumption, and high noise from the air compressor also limit its application.

1. When starting work every day, check whether the sewage inlet pump and reflux pump of the dissolved air flotation machine are frozen. This includes checking the lubricating oil filling of the pumps, the tightness of the packing, the sealing of the foot valve, and the oil filling of the air compressor.
2. Check whether the air water filter valve of the air compressor is frozen to determine if the air compressor is operating normally, and check for abnormal noise or overheating.
3. Check the transmission part and scraper of the slag scraper to see if they become hard and break in cold conditions, so as to avoid affecting usage.
4. Pay attention to preventing the coagulant mixing and storage tank from freezing, and conduct small-sample tests regularly.
5. Inspect the valves and pipelines of each equipment to prevent blockage, and set them to the "open" or "close" position as required.
6. When shutting down the machine, the water must be drained completely to prevent freezing and blockage.