TORAY MBR
Instruction Manual
06-G-MB2-NHPAC-220801
44 of 61
2. Air Diffuser Cleaning
A clogged air diffuser cannot evenly distribute air to the membrane elements resulting in,
which causes that solids build up on the membrane element surface, or, in extreme cases,
the membrane element gets damage.
It is recommended that the MBR module(s) be
equipped with air diffuser cleaning components/valves that can be automatically
controlled from the MBR system PLC. Cleaning of the air diffusers should be
performed at least once per 24 hours or as needed to maintain even air distribution.
To
clean the air diffuser holes, it is necessary to flush the activated sludge through the diffuser
holes into the diffuser piping and finally out from the air/sludge discharge nozzles. This is
accomplished by supplying air to the diffuser piping in the reverse direction (see below). The
flow of air through the diffuser and out the discharge nozzle will create a suction drawing off
the sludge into the diffuser piping. This reverse flow of sludge that will remove any
accumulated solids clogged in the diffuser holes. The efficiency of the air diffuser cleaning
will improve by the reverse procedure of the air flow direction indicated above.
Observe the flow coming out of the discharge nozzles (V2 and V4) when performing an air
diffuser cleaning cycle. In some cases, lengthening the duration of the diffuser cleaning cycle
can improve the efficiency of the diffuser cleaning cycle.
(1) Air Diffuser Cleaning Procedure - Principle
(i)
The filtration must be stopped at first.
(ii) Open V2 discharge nozzle valve.
(iii) Close V1 valve. These valve settings will result
in liquid sludge flowing through the diffuser
holes, into diffuser piping, and the mix of air and
sludge will be discharged through V2.
(iv) Keep V2 valve open for 1 to 5 minutes.
(v) Open V1 valve, and then close V2 valve.
(vi) Clean the other line in the same manner as
follows.
(vii) Open V4 discharge nozzle valve.
(viii) Close V3 valve. These valve settings will result
in liquid sludge flowing through the diffuser
holes, into diffuser piping, and the mix of air and
sludge will be discharged through V4.
(ix) Keep V4 valve open for 1 to 5 minutes.
(x) Open V3 valve, and then close V4 valve.
(xi) Restart the filtration after one minute.