Regeneration of Demineralised Water Plant

 In this post Standard Operating Procedure of Regeneration of Demineralised Water Plant in Pharmaceuticals is describe.

Purpose: To lay down operating procedure for regeneration of demineralised water plant.

Scope: This procedure is applicable for ................

Responsibility: Production Chemist

                           To supervise the activity

EQUIPMENTS USED:

1. Portable Deioniser

a) For anions & cations (Model CA-60 U)

b) For Mixed bed (Model MB-25)

PROCEDURE:

A. Regeneration of cations:

1. Acid Preparation:

a) Take 22 ltr of DM water in an anticorrosive container .

b) Add 10 ltr. HCL into it & stir well.

c) Pour this solution into the regenerant container.

2. Acid injection:

a) Open valve B fully.

b) Open & adjust raw water supply valve to get a flow of 1.25 litre/min.

3. Acid Downflow Rinse:

a) Pour 16 ltr. of DM water into the regenerant container & connect to

raw water supply valve. Open B fully.

b) Open & adjust raw water supply valve to give a flow of 2.5 liter/min.

c) Repeat the step a) for another 16 ltr. of DM water.

4. Acid up Rinse:

a) Reconnect raw water inlet tube to the raw water supply valve.

b) Close the diaphragm valve.

c) Open valve C & D. Open & adjust raw water supply valve to give a

Flow of 5.0 liter/ minute.

d) After 20 min., close valve C & D & raw water supply valve.

B. Regeneration of anions:

1. Soda preparation:

a) Take 32 ltr. of DM water in an anticorrosive container.

b) Add 2.4 kg of caustic soda, stir to dissolve & allow to cool.

2. Soda injection;

a) Take 16 ltr. of soda solution in a regenerant coontainer &

Connect the tubing at the top to raw water supply valve.

b) Close the diaphragm valve.

c) Open valve A&D. Open & adjust raw water supply valve to give flow rate of 1.25liter/minute.

d) Repeat the procedure for another 16 ltr. of soda solution.

3. Caustic Rinse:

a) Pour 16 liter of demineralized water into regenerant container after ensuring

that it has thoroughly drained.

b) open valve A & D. Open raw water supply valve & adjust to giive a flow of 2.5 liter/ minute.

4. Final rinse:

a) Open raw water supply valve & diaphragm valve.

b) Open valve C & adjust to give a flow of 10 liter/ minute.

c) Maintain the flow till conductivity falls to an acceptable limit.

d) Regeneration of Mixed Bed

1. Backwash :

a) Open valve D fully.

b) Open & adjust valve B to get the backwash flow of 4.5 ltr./min.

c) Maintain the flow for 10 min.

2. Settle:

Close all valves for 10 min.

3. Soda injection:

a) Prepare a solution of 0.750 kg caustic soda in 12 ltr of DM water & pour into the regenerant container.

b) Open valve E fully.

c) Adjust valve G to maintain the flow within 10 min.

d) Close E & G.

4. Soda Rinse:

a) Open valve E fully.

b) Open & adjust valve G such that the rinse water is emptied in 10 minutes..

c) Close E & G.

5. Acid injection:

a) Prepare a solution of 1.8 ltr. HCl in 7.5 ltr. D.M

c) Adjust valve H such that solution flows out in 10 minutes.

6. Acid Rinse:

a) Flush out excess acid with 7.5 ltr. DM water.

b) Open F fully & adjust H such that solution flows out in 10 mins.

c) Close F&H.

7. Air-mix:

a) Open D & H fully.

b) Connect PVC tube to the air blower & switch it on.

c) Carry out air mix for 10 minute at minimum pressure of 1 kg/cm².

8. Settle after Air-mix

a) Disconnect air inlet tube from air blower.

b) Open valves A,C & raw water supply valve to give maximum possible

flow.

c) Close D & H.

d) Switch off the air blower.

e) After 1 minute, open valve D to release any air that may be entrapped

inside the unit.

9. Final rinse:

a) Close valve D & adjust raw water supply valve to maintain the flow

of 4.5 ltr./min.

b) Continue rinse for 10 min.

c) Switch on the conductivity indicator.

d) If conductivity does not fall below 1 microsiemen /cm, repeat step7,8&9.

e) Check the pH of the water as it should be in the range of 5.5 to 7.5.

f) If it is found within limits, connect the raw water supply & collect

the final water for use.

10. Sampling:

a) Intimate the QA Dept. for sampling for chemical & microbiological

Testing.

Precautions:

1. The regeneration procedure must be continuous.

2. While carrying out steps 3,4,5& 6 of mixed bed regeneration , never allow the regenerant container to drain fully. Close the specified valves to prevent air locks.

3. Place the air blower at a height above the top of unit to avoid

4. Avoid contact of acid & alkali with eyes, skin & clothing.

5. Always wear goggles & gloves while handling the chemicals.

6. When diluting acids, always add acids to water slowly & carefully.