Dissolved Air Flotation Clarifier

Dissolved Air Flotation (DAF) is an effective method of treating industrial wastewaters especially from paper mills, dairy units, textile industries, tanneries and food processing like edible oil refining, fisheries, meat processing etc. Recent applications would also suggest that it is an ideal process for clarifying mixed liquor from aeration basins of activated sludge systems.
State-of-the-art DAF clarifies are circular in shape with a retention of 3 minutes, compared to rectangular first generation DAF units of 20-30 minutes retention. Daftech Floatcells have done away with overflow weirs which use extra space and warrant extra supporting columns. Daftech Floatcells operate with a pressurized recycle flow of 25 � 30% and generate fine bubbles of 30 micron size which lift the suspended particles to the top surface from where it is picked up by a scoop. Clarified water from Floatcell will not have TSS more than 50 ppm. BOD reductions generally achieved vary between 50 and 80 % depending upon the nature of solids removed. The other advantage of using flotation is that the sludge separated has a much higher consistency, 2 - 3.5%, as against 0.8 � 1% from the bottom of conventional sedimentation clarifiers. Daftech Floatcell employs imported German variable speed gear motors for the drive systems. The speed is steplessly variable over a range of 3-21 RPM. Where the standard construction is mild steel with a special anti- corrosive paint, fabrication in SS 304 and 316 also are offered to overseas clients and special applications. The equipment comes prefabricated and can be erected at site in 5-7 days.