新宝GG

How does the DAF work

Column:Industry news Time:2020-10-13
Dissolved air flotation, also called DAF, has been widely used for the pretreatment and advanced treatment in sewage industry.

When waste water entering the reaction areas, flocculant (PAM) and coagulant(PAC) would be added into two reaction tanks separately.

Through enough and effective flocculation reaction, raw water enters the contact areas of DAF.

In the contact areas, Micro bubbles in the air-dissolved water adhere to the flocculated suspended solids and will be together going to the next separation areas.

The suspended solids surrounded with many micro bubbles, has a density lower than that of  water, so that the Flocs and bubbles rise to the liquid surface together to form scum to realize solid-liquid separation.

The scum is scraped to the sludge area by the skimming device, and the clean water in the lower layer flows to the clean water tank through the water collecting pipe. Part of the clean water is returned to the air-dissolved system for use, and the other part is discharged.

Returned water lifted by pumps is mixed with compressed air in the air-dissolved tank that produces saturated air-dissolved water. Liquid level controller is set on the tank. The whole set of equipment can realize unattended and automatic operation, and it also has remote start and stop fault signal.

Air-dissolved water in the contact area is released through the rapid decompression of micro bubble generators, forming about 30μm~50μm diameter micro bubbles which will adhere to the suspended solids.

Venturi mixer is used in the air dissolving tank, effectively preventing blockage.

The dissolved air system adopts Yosun patent technology with the advantages of high efficiency, tiny bubbles and anti clogging.

DAF runs stably as a whole with a low failure rate. The blocked micro bubble generators can be  disassembled and overhauled without stopping the machine. The non-metallic chain slag scraper can cover the whole tank and scrape slag with multiple plates, which is stable and reliable.


新宝GG