In the production process of deionized water equipment, the purpose of inspecting ion exchange resin is mainly to check the quality of the new resin, and to understand the quality change of the resin after use. Test data is required before the resin is used, and the resin is tested regularly after half a year of use. Cleaning and transformation are required before ion exchange resin testing. For example: the cation resin is converted to sodium type, and the anion resin is specially chlorine type, so that the analysis can be performed on the same basis.
Check the purpose of ion exchange resin
1. The total exchange capacity of the ion exchange resin. Complete exchange capacity is an important indicator of resin performance. The greater the exchange capacity, the more ions that the same volume of resin can absorb, the greater the cycle water production, and the lower the corresponding acid-base consumption. It is also convenient to check the total exchange capacity.
2. The working exchange capacity of the ion exchange resin. Working exchange capacity is an important technical indicator of resin exchange capacity, which refers to exchange capacity under dynamic work. The size of the working exchange capacity is related to the influent ion concentration, end point control, resin layer height, and exchange speed. Therefore, the measurement of working exchange capacity has important practical value.
3. The mechanical strength of ion exchange resin. The resin rubs against each other during use, as well as the expansion and contraction of the resin during each operation cycle and the surface pressure, which will cause the resin to rupture and crush, and the mechanical strength of the hydrogen resin is tested. It is related to the service life of the resin.
4. Density detection of ion exchangers. The apparent density of the detected resin is used to calculate the amount of wet resin required by the ion exchange tower. The wet apparent density is generally 0.6-0.85g/ml. Testing the wet density of the resin is convenient to determine the backwashing strength, and has a great relationship with the layered resin in the mixed bed. The wet true density is generally about 1.04-1.30g/ml.
5. Moisture contained in ion exchange resin. Because there is a certain amount of moisture in the resin mesh, it is related to the degree of crosslinking and porosity of the resin. The smaller the degree of crosslinking, the greater the porosity. Therefore, detecting the moisture content of the resin to calculate the moisture content can indirectly reflect the crosslinking of the resin. The size of the degree. Generally, the water content of resin is about 50%.
6. Particle size of ion exchange resin. The particle size has a great influence on the resin exchange capacity, the uniformity of water flow distribution in the resin layer, the pressure drop of water through the resin layer, and the exchange backwash operation. The smaller the particle size of the resin, the greater the exchange rate, the greater the hydraulic loss, and the greater the pressure difference between the inlet and outlet water. Therefore, the granularity has a great relationship with the operation.
7. Neutral salt decomposition capacity of ion exchange resin. Detecting the decomposition capacity of resin neutral salt is mainly to determine the composition of strong acid or strong base groups in the resin. Because the composition of the resin exchange group is different, the ion exchange and adsorption strength in water are also different. In addition, detecting the decomposition of neutral salts is also measuring the dissociation ability of the resin exchange group. If the dissociation ability is strong, the ion exchange rate is fast, otherwise, it is slow. Detecting the neutral salt decomposition capacity of the resin is very important for selecting the resin.
8. The ash molecules and iron content in the ion exchange resin, ash and iron will sink on the surface of the resin, block the pores, and are not easy to wash out. Long-term accumulation will affect the exchange capacity and service life of the resin. Therefore, timely detection and measures are needed.
9. The oxygen consumption of ion exchange resin. Oxygen consumption mainly reflects the degree of contamination by organic matter. After the resin is contaminated by organic matter, the cleaning water consumption increases sharply, the working exchange capacity decreases, and the effluent water quality is poor. Check the oxygen consumption of resin. In order to judge the degree of resin contamination, take effective measures in time