1. Pretreatment of new resin:

Due to transportation, storage and other reasons, it is easy to dehydrate the new resin. It can be found with the naked eye and hand feeling. In this case, in order to avoid bursting and crushing caused by the contact between the resin and water and other regeneration solutions, and cause unnecessary waste, such resin must be immersed in 8% salt water for about 16 hours (often stirred during immersion), so that the resin can be fully expanded, and can only be used after rinsing with clean water until it has no salt taste. Without the above phenomenon, the resin does not need to be pretreated.

2. Resin filling:

The resin filling height of domestic mixed bed equipment is 5 (6) 00mm for cation resin and 10 (2) 00mm for anion resin. In non ecological conditions (i.e., when the cation resin is sodium type and the anion resin is chlorine type), the cation resin filling height shall not be higher than the middle discharge port, but shall not be 5cm lower than the middle discharge port. The filling ratio of anion and cation resin is 2:1 (or 1.5:1). Cation exchange resin is at the bottom and anion exchange resin is at the top.

3. Resin flushing:

After the resin is loaded into the exchanger, backwash the resin layer with clean water until the water is clear, odorless and free of finely broken resin. Use 4-5% HCl solution about twice the resin volume to pass through the resin layer at a flow rate of 2m/h. After all the water is introduced, soak it for 4-8 hours, drain the acid, wash it with clean water until the effluent is neutral, and the washing flow rate is 10-20m/h. Use 2-5% NaOH solution about twice the volume of the resin, and inject and soak it as per the method of adding HCl solution above. Drain the alkali liquor, wash with clean water until the effluent is neutral, and the flushing flow rate is the same as above. If the acid and alkali solutions can be repeated for 2-3 times, the effect will be better.

4. Cation anion resin mixing:

After flushing, open the lower inlet and upper discharge valves, start the intermediate water pump (backwashing will loosen the resin layer), and when the accumulated water in the column is drained to 100-150mm above the resin layer, close the intermediate water pump and inlet valve; 2. Open a small amount of vent valve, open and control the air intake volume of the air intake valve (the air intake pressure is 0.1-0.15mpa), and observe the rhythmic up-down boiling mixing of the resins in the upper and lower sight glasses, so that the color of the upper and lower resins is the same. The air inlet time is generally 10-15 minutes; 3. After mixing, close the air inlet valve and the vent valve, and then quickly open the upper inlet valve, the middle water pump and the lower discharge valve (to make the resin settle rapidly and prevent the resin from re stratification in the settling process). At the same time, prevent the resin from coming out of the water, otherwise bubbles will be generated between the resins, which will affect the effluent quality of the mixed bed (if

When the mixing effect is poor, the mixing operation can be repeated).