Regeneration of DM Plant 

PROCEDURE   

Frequency: When the TDS of DM water reaches 50 ppm.

Regeneration of the Demineralized water is done by ion exchange process for both Cation and anion exchanger.

Cation exchanger is regenerated first followed by regeneration of Anion exchanger. Cation exchanger is regenerated by HCl and Anion exchanger is regenerated by NaOH.

Regeneration of Cation Exchanger

Backwash                  

Close the inlet valve, injection valve, drain valve and outlet valve.

Open the valve, wash inlet, and wash outlet valve subsequently.

Continue washing for 10-15 minutes or until the water is clear.

Injection

·         Prepare the 30% HCl solution in tank by adding 50 liter of HCl in 150 liter of water.  

·         This HCl solution of 30% concentration shall flow to Cation exchanger through pressure.

·         Open the HCl solution inlet valve slowly, the rinse outlet valve should be open.

·         HCl from the HCl mixing tank shall be injected into top of the Cation vessel.

·         When the level of HCl solution in the tank reaches the clamp or disc on the suction pipe, close the HCl solution inlet valve and then rinse outlet valve.

·         Control the HCl solution inlet valve in order to complete injection in not less than 15 min.  

Rinse

·         Close the injection valve.

·         After completion of injection close the injector valve and start slow rinse and after that start fast rinse by controlling the valve.

Regeneration of Anion Exchanger

Backwash                  

Close the inlet valve, injection valve, drain valve and outlet valve.

·         Open the valve and wash inlet, and wash outlet valve subsequently.

·         Continue washing for 10-15 minutes or until the water is clear.

Injection

·         Prepare the 10% NaOH solution in tank by adding 10 kg of NaOH in 100 liter of water.  

·         This NaOH solution of 10% concentration shall flow to Anion exchanger through pressure.

·         Open the NaOH solution inlet valve slowly, the wash outlet valve should be open.

·         NaOH from the NaOH mixing tank shall be injected into top of the Cation vessel.

·         When the level of NaOH solution in the tank reaches the clamp or disc on the suction pipe, close the NaOH solution injection valve and then wash outlet valve.

·         Control the NaOH solution inlet valve in order to complete injection in not less than 15

              min.                                                                           

Rinse

·         Close the injection valve.

·         After completion of injection close the injector valve and start slow rinse and after that start fast rinse by controlling the valve.

·         Open the rinse outlet valve and check the TDS.

·         Monitor the TDS from TDS meter at outlet valve V15.

·         When a satisfactory level of TDS has been obtained, close the rinse outlet valve.

·         The DM plant is now regenerated and ready for operation.

·         Open the outlet valve to service.