23
3.
Toray Maintenance Cleaning
Instead of chemical dosing for every backwash, soaking the membrane to
chemical solution several tens of minutes a day is also effective for membrane
performance retention. This process is called Toray Maintenance Cleaning
(TMC). The TMC is usually held following the backwash and air-scrubbing
which does not contain the chemical dosing. The frequency and soaking time
of the TMC mainly depends on the raw water quality (Normally once a day and
each soaking time are 20 minutes. Please contact us if you need technical
support.). Fig. 5 shows a typical example of flow diagram for the TMC.
(1)
Open the air exhaust valve (V-4) and the drainage valve (V-3).
(2)
Open the backwashing valve (V-6), run the NaClO feed pump and the
backwashing pump to feed the chemical enhanced backwash water to the
membrane module.
The flow rate of backwash water is set up in advance for 1.0 to 1.5 times
filtrate water flow rate (Do not exceed Max. Backwash Flow described in
Fig. 5 Flow diagram for the TMC
