RO Water Distribution/Recirculation System
RO Water Distribution/Recirculation System
(OP)
Hi,
I am not an Engineer so I decided to come here and hopefully one could help me. We have a newly installed Reverse Osmosis Water System in our facility. The piping is polypropylene and is 32mm in diameter. If needed I can get the pump info but don't have it here now.
We would like to know the minimum flow rate that is needed to generate a turbid flow. Turbid flow is needed to prevent the buildup of biological material (biofilm i.e. bacteria, mold, etc.) from growing in the system.
The answer or a place to go and find it for ourselves would be greatly appreciated.
Do you need to know the pressure of the system, HP or RPMs of the motor (Pump), number of drops etc.?
Thank you,
vikingkerny
I am not an Engineer so I decided to come here and hopefully one could help me. We have a newly installed Reverse Osmosis Water System in our facility. The piping is polypropylene and is 32mm in diameter. If needed I can get the pump info but don't have it here now.
We would like to know the minimum flow rate that is needed to generate a turbid flow. Turbid flow is needed to prevent the buildup of biological material (biofilm i.e. bacteria, mold, etc.) from growing in the system.
The answer or a place to go and find it for ourselves would be greatly appreciated.
Do you need to know the pressure of the system, HP or RPMs of the motor (Pump), number of drops etc.?
Thank you,
vikingkerny





RE: RO Water Distribution/Recirculation System
We also use UV sterilization and microfiltration to destroy and remove any biological matter that is present before the water enters the distribution system.
Hope this helps!
---KenRad
RE: RO Water Distribution/Recirculation System
Bob
RE: RO Water Distribution/Recirculation System
Removal of biofilms and preventing the formation of biofilms require high velocities. One article I read from Pharmaceutical Engineering suggests 1.5m/s to 3m/s velocities which can create enough force to shear off the biofilms. If found I will give you the tabulated data. As Kenrad already suggested minimise the dead legs. Keep the dead leg portion not greater than 2 times the diameter of the pipe and try using zero dead leg valves instead of y loops.
Regards,
RE: RO Water Distribution/Recirculation System
Post the question on the water treatment forum for details.
Plenty of websites with data on the cleaning systems. If fact the manufacturer of your susyetem should provide you with details as part of the operating and maintenance instructions.
RE: RO Water Distribution/Recirculation System
This minimum flow rate would be what you would want in the return section of the loop when there is the maximum amount of drawoff from the drops. You would make an estimate of the expected maximum flow, based on the total number of drops, the number of drops that might reasonable be expected to be open at one time, and the flow per drop. Your pump needs to provide that flow plus the flow in the return section of line equal to 3 fps. That is the design case. The pump needs to provide the head to accomplish this. During periods with no draw off at the drops, or minimal draw, which is probably much of the time, the pump will run out on its curve and the "normal" flow rate through the system will be higher (probably 4 to 6 fps).