Method for use of mixed bed ion exchange resin

1. Pretreatment of new resin:

Due to transportation and storage reasons, it is easy to dehydrate the new resin. Can be seen by the naked eye and feel. In this case, in order to avoid the contact between the resin and water and other regenerated liquid and burst and break, resulting in unnecessary waste, such resin must be soaked in 8% salt water for about 16 hours (often stirred when soaking), so that the resin fully expanded, rinsed with water until no salt taste can be used. Without the above phenomenon, the resin does not need to be pretreated.

2. Resin filling:
The resin loading height of the domestic mixed bed equipment is positive resin 5(6)00mm, negative resin 10(2)00mm, non-ecological (that is, when the positive resin is sodium type and the negative resin is chlorine type) positive resin loading height can not be higher than the middle outlet, but it should not be lower than the middle outlet 5cm. The ratio of Yin and Yang resin is 2:1(or 1.5:1). The cation exchange resin is on the bottom, the anion exchange resin is on the top.

3, resin washing:

After the resin is loaded into the exchanger, the resin layer is backwashed with clean water until the water is clear, odorless and no broken resin. A 4-5%HCl solution of about 2 times the volume of the resin was used to pass through the resin layer at a flow rate of 2m/h. After all through, soak for 4-8 hours, drain the acid, rinse with clean water until the water is neutral, flushing flow rate of 10-20m/h. With 2-5%NaOH solution of about 2 times the volume of resin, pass and soak as above into HCl solution. Drain the lye, rinse with clean water until the effluent is neutral, flushing flow rate is the same as above. If the acid and alkali solution can be repeated 2-3 times, the effect is better.

4, Yin and Yang resin mixing:

After the end of washing, open the lower inlet and upper discharge valves, start the intermediate water pump (backwashing loosens the resin layer), and close the intermediate water pump and water inlet valve when the water in the column is discharged to 100-150mm above the resin layer; 2, open a small amount of exhaust valve, open and control the intake air volume of the intake valve (intake pressure is 0.1-0.15Mpa), observe the resin in the upper and lower glasses have a rhythm of up and down boiling mixing, so that the color of the upper and lower resin mixed consistent. Intake time is generally 10-15 minutes; 3, after the end of mixing, close the intake valve, exhaust valve, and then quickly open the upper valve, intermediate water pump, and lower exhaust valve (so that the resin quickly settlement, to prevent the resin in the settlement process re-stratification). At the same time, it is also necessary to prevent the resin from emerging from the water surface, otherwise there will be bubbles between the resins, which will affect the water quality of the mixed bed (If the mixing effect is not good, you can repeat the mixing operation).