Reverse Osmosis Membrane Replacement at the Gold Coast Desalination Plant
Overview of Project:
Metal Maintenance was engaged by Veolia to replace the reverse osmosis membrane at the Gold Coast Water Treatment Plant.
Scope of Works:
The Scope of Works for this Project included:
- Manufacturing specialised equipment to remove and replace the membranes,
- Removal and replacement of 3,456 2nd Pass Membranes,
- Removal and replacement of 13,392 1st Pass Membranes,
- Detailed QA/QC documentation.
In the weeks prior to work commencing onsite, Metal Maintenance came up with an innovative method to remove and replace the reverse osmosis membranes in an safe and efficient manner. Neumann Equipment designed and manufactured a pneumatic reverse osmosis membrane unloader/loader, which removed the manual requirement of pushing the membranes into the vessels.
Removal and Replacement Activities
- Permeate Pipe Removal
Using the mast climber two teams of three ascended either side of the train and removed all the permeate pipes from each pressure vessel. All pipes had any thread tape removed and were placed in a specified storage container ready for re-fit.
- End Caps Removal & Cleaning
Following the same process as outlined during permeate pipe removal the teams ascended both ends of the train and removed the end caps and placed them in specified containers. These containers were lowered down periodically to allow cleaning, preparation, and the storage of the end caps, which were completed as per TSB122 – Element Loading Guidelines.
- Membrane Removal & Vessel Cleaning
A hydraulic extractor was be used to push the membranes out of the vessels using permeate. A cleaning sponge was then placed in position behind the last membrane prior to the hydraulic extractor being fitted.
One person operated the hydraulic extractor, while another person, located at the discharge end of the vessel with a custom designed tray receiver accepted the membranes as they were pushed out. Each membrane was pushed onto the tray provided until all membranes and interconnectors were removed. The cleaning sponge cleaned the vessel during the discharge of the membranes and the permeate flushed any debris from the vessel. All interconnectors were placed in a storage containers and once each vessel is completed the interconnectors and membranes trays were lowered to the ground for processing, cleaning, and O-ring replacement. This process was duplicated until all the membranes have been removed from the reverse osmosis train.
The unloading trays were lowered to the ground where they where they were moved to a different area where membranes are being repackaged for re-use.
- Vessel Inspection
Each vessel was inspected for any damage or dirt inside which was reported to the supervisor for further investigation by Gold Coast Desalination Plant.
- Membrane Loading
Membrane loading was processed using the following procedure.
All front side end caps were fitted, during the refitting of the endcaps the pneumatic membrane loaders was setup and positioned. The vessel was then be lubricated as per TSB122 – Element Loading Guidelines.
Membrane trays were loaded at ground level on the sorting and loading benches. The assigned QA team member recorded the serial numbers of each membrane and placed the membrane onto the loading tray in the position required in the vessel. Each tray was then passed up to a specific vessel operator for installation.
All O-rings and seals were lubricated with glycerine. Each membrane was then loaded into the vessel using the pneumatic loader with interconnectors being fitted during the process. Two QA persons were provided to inspect preparation, loading, and shimming of all membranes.
Once all membranes were loaded, each vessel was shimmed as per manufacturers specifications and the end caps were installed. This process continued for all remaining vessels.
- Permeate Pipe Clean & Install
All permeate connection pipes were cleaned, and joints had thread tape applied and re-installed on each pressure vessel.
The project was completed on time and on budget. Veolia Water was extremely happy with the innovative way the works was completed.