TORAY MBR
Instruction Manual
06-G-MB2-NHPAF-220801
52 of 63
(iii) Stop the filtration process, stop module aeration, and finally close the filtrate
valve.
(iv) Open the chemical feed valve and start the chemical feed pump.
(v)
Confirm that the outlet of the pressure relief pipe is free of obstructions and
that any cleaning solution being discharged is flowing freely back into the
chemical tank. If the flow from the relief pipe is excessive, make any
necessary adjustments to the chemical pump flow to reduce relief pipe
discharge flow.
(vi) Slowly open the chemical injection valve to start injecting the chemical.
(vii) After injecting the specified amount of chemicals to the elements, close the
chemical injection valve and stop the chemical feed pump.
(viii) Allow the membrane elements to soak for 1 to 3 hours.
(ix) After the soaking period close the chemical feed valve, open the filtrate valve,
and start aeration. Finally resume the filtration process.
*
When starting up the MBR after a chemical cleaning, some residual cleaning
chemical may be present in the filtrated water for 2 or more filtration cycles. It
is recommended that the filtrate flow be directed back into the raw water tank
until no residual cleaning chemical is detected. Before directing the filtrate
from the raw water tank back to the normal filtrate discharge line, test the
filtrate pH and chlorine concentration.
Fig.VIII-4 Chemical Cleaning with the Chemical Feed Pump and Relief Piping
Do not attempt to inject chemicals, using a chemical feed pump,
without installing a pressure relief pipe and associated air gap.
Excess internal element pressure will damage the membrane
element.
If the flow from the relief pipe is excessive, make any necessary
adjustments to the chemical pump discharge flow to reduce relief
pipe discharge flow. Use the safety equipment such as goggles
and gloves when inspecting discharge piping and making
adjustments.
WARNING
!
WARNING
!
Module
Low Water Level of
Membrane Tank
Filtrate
water valve
Chemical
Feed Pump
Chemical Tank
1,000 mm (=10 kPa) or less
Relief
Piping
Chemical
Feed Valve
Chemical
Injection Valve
Air Gap
