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2.
Backwash and Air-scrubbing
The physical cleaning with backwash followed by air-scrubbing should be carried
out periodically and automatically for the continuous filtration. The frequency of
the physical cleaning mainly depends on the raw water quality (Typical frequency
is once every 30 minutes normally for surface water filtration. Please contact us
if you need technical support.). Fig. 4 shows a typical example of the flow
diagram for backwash and air-scrubbing.
(1)
Close the feed water valve (V-1) and stop the feed water pump.
(2)
Open the air exhaust valve (V-4).
(3)
Close the filtrate water valve (V-5) and open the backwashing valve (V-6) to
feed back the filtrate water from the backwashing tank to the membrane
module. During backwash, chemical feed pump can be operated to dose
chemical to the backwash water. The dosing chemical is usually sodium
Fig. 4 Flow diagram for backwash and air-scrubbing
