Shutting Down And Restarting Electrocoating Anolyte Systems
It may be that your company has experienced an unexpected shutdown as times grew uncertain earlier on in the year. Equally you could be suddenly resuming production and need your systems to run smoothly.
This blog will run through how to approach restarting your anodes and anolyte systems after being suddenly shut down. You can also view it as a guide, click here.
Restarting Anolyte Systems After Unexpected Shutdown
Unexpected events may call for plants to be idled or even closed down for a number of weeks. Electricity and a source of pure water may or may not be available during this time.
Best practise is to keep the ion-exchange membranes of the anodes wet and take steps to suppress the growth of biological organisms. In turn, this means keeping the anolyte pump running 24/7 and using approved biocides on a rotating basis, or Ultraviolet bacteria control, so the organisms don’t develop immunities.
Since the goal is to restart the e-coat paint system once the plant is re-opened, dependent on your situation, if electricity and pure water is available or there is no electricity or pure water, there’s maintenance that should be done before the plant is shutdown.
Tasks To Be Completed Regardless Of Scenario
The Anode Cells should be full of anolyte or DI/RO water (pure water).
Some fluid will be lost to evaporation, however, since the exposed surface area (inside the neck of the Tectron Cell) is low compared to the total volume of anolyte, evaporation should be at most, 1 or 2 inches per month.
An improved biocide should be added (at the upper end of the recommended dosage range) into the anolyte tank and allowed to mix for 4 hours minimum with the make up RO inlet water valve turned off.
Shutting Down With Electricity And Pure Water Supply Available
If you have electricity and pure water available you should keep the anolyte pump running 24/7 in order to supress the growth of biological organisms.
At some point, the effectiveness of the biocide may begin to degrade, if so, add more biocide (at the upper end of the recommended dosage range) and allow to mix. Repeat this as often as necessary.
If more than 2 inches of liquid is lost in the anolyte tank, refill with pure water and add an appropriate amount of biocide based upon lost volume of anolyte since the last addition.
Alternatively, if Ultraviolet bacteria control is used, make sure that the quartz is cleaned and the system is left operational.
Shutting Down When Electricity And Pure Water Supply Is Not Available
If the paint tank is drained, rinse the paint solids from the exterior of the anode cell with a water hose. Do not use a pressure washer as it can damage the fragile ion-exchange membrane.
Make sure the Anodes cells are left filled with pure water.
Upon restarting the system and when pure water is available, drain and refill the anolyte tank with pure water and circulate through the anode for 1 hour. Drain the system completely and restart again with a fresh tank of pure water and circulate, adding approved chemicals to reach the desired microsiemens level.
Conclusion
Sometimes sudden events or circumstances mean a sudden shutdown of operational e-coating systems. Dependent on if you have electricity and pure water available or not there are procedures you can follow to ensure the systems don’t get damaged or blocked up.
Membracon can help and advise with any operational shut downs or restarts. They specialise in not only recommend and supplying the right filtration system for your processes but also maintaining and servicing them throughout the year.
Here’s some more information on E-Coating processes: