flow ration between air and water - AERATION PUMP 1

[sebastianS]

Hi folks,


I'm trying to get more opionions of someone who has experience with aeation pump for DAF unit. As I know flow ratio, I need opinion of you guys with experience in this field what is best flow ration between air and water, when sizing the aeration pump.

Thanks,
Andreas

 

[bimr]

In the DAF process, a sidestream of 5 to 15 percent of the raw water is recycled. The preferred method of operating the DAF involves use of a compressor to dissolve the air, not drawing air into the suction of a pump. The air is dissolved into the discharge of a pump operating at approximately 60 psi. See the scheme depicted in Wikipedia.

 

[sebastianS]

this is old system ,

I need best of the best


type of pump is : EDUR - PBU Series


Thanks

 

[bimr]

That is the optimal DAF system used in high performance applications like paper. If you want to design a lower performance system such as a dispersed aeration system used in mining or food wastes, you need to say what the application is.

If you read the sales flyer for the EDUR - PBU Series, the manufacturer does not understand how DAF systems work. In the traditional DAF design, the air is dissolved in water, not entrained or entrapped. When the pressure is released with the control valve, the air will come out of solution, thereby forming minute bubbles.

 

[EdStainless]

In this application you don't want to try and pump bubbles, just saturated air.
In the old days (and for some other aeration applications people put eductors in the line and let the water suck in air, but it is easy to end up with too much air.

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P.E. Metallurgy, Plymouth Tube

 

[sebastianS]

hi guys ,

DAF is for the treatment of industrial wastewater.

Do you have experience with DAF system /design, so what PUMP you suggest here, I want best system best pump no matter how much cost all together, just give me what is best solution.

 

[bimr]

You can use a standard centrifugal pump in whatever configuration works for the recycle stream. The air release valve is typically a globe type.

Conversely, you can use one of the DAF pumps that inject the air. However, read the performance claims with skepticism.

The DAF supplier should be furnishing a complete system that includes the air injection system.

 

[sebastianS]

Thank you