Cleaning a Plate Type HE (Heat Exchanger)
Cleaning a plate type HE (heat exchanger) made of stainless steel-use the following recommended procedure:
Procedure for chemically cleaning a plate type HE (heat exchanger) of stainless steel.
Note- First obtain a correct deposit analysis of material in the HE (heat exchanger)
1. To begin the cleaning a plate type HE, set up a 55 gal barrel ½ full of water, recirculation pump to pump into the heat exchanger, and return back from the heat exchanger to the barrel.
2. Then add 10 # of RTA Powdered Delimer, or equivalent, to the barrel and mix to dissolve.
3. Start circulation to the heat exchanger with the pump.
4. Test the ph of the returning solution. It normally will not go lower than 3 or 4.
5. When the ph rises to about 6.5 to 7.0, add more Powdered Delimer.
6. Continue to add more delimer until the ph no longer rises for ½ to 1 hour from its low point when the Powdered Delimer is added.
7. Dispose of the solution in the barrel and in the system, and flush the system with water.
8. Refill the barrel with water, add ½ gal of RTA 1130, or Caustic Soda 50%, and recirculate for 15 minutes.
9. Drain and rinse the system with water by pumping water through the heat exchanger.
Disposal of the solution in the system and in the barrel
- Drain the system and discharge the solution in the barrel safely to drain. Normally the effluent may be sent to drain since the pH is between about 6.5 and 9.5. Flush the system with water.
- Refill the barrel with water, add 1 qt to ½ gal of RTA 1130 (diluted 50%), or Caustic Soda 50%, and recirculate for 15 minutes.
- Make sure that the circulation water tests higher than 8.3 ph. (Add 1 drop of Taylor #638 reagent, or equivalent phenolphthalein indicator solution-test sample turns red if above 8.3 ph)
- Drain and rinse the system with water by pumping water through the heat exchanger.
Acid Test Procedure (See Step 4 of instructions above)
The use of Tridicator pH paper, or equivalent wide range pH paper. It is usually acceptable for determining pH.