Technical help: Conductivity and concentration factor

Is there something unclear about this topic? What is the relationship between the conductivity of water and the concentration factor? I don’t think I’ve heard of it.

Generally, when making simple calculations, conductivity is usually used to calculate the concentration factor, that is, the conductance in the circulating water/the conductance in the replenishing water is directly used. This is not commonly used now, because in addition to the concentration process, fungicides, retardants, sulfuric acid, etc. are also added to the system, which increases the conductance in the system. Now when conductivity is used to calculate the concentration factor, this value is much larger than the actual value.

The accurate measurement method of concentration ratio is the K ion method. Because the chemicals added during the operation of circulating water do not contain potassium ions, the measured results are more accurate.； Conductivity generally indicates the salt content in water. When the conductivity is greater than a certain value, sewage discharge is required. ； The conductivity of circulating water and the conductivity of fresh water can be used to estimate the concentration factor. Although it is not accurate, it has certain reference significance. Another method of calculating the concentration factor is the ratio of chlorine and ions in the circulating water to the chlorine and ions in the supplementary water.

The concentration factor is expressed by the ratio of the salt concentration of a certain component in the circulating cooling water and the salt concentration of a certain component in the supplementary water. However, generally the salt concentration of a certain component being detected should not change due to external conditions, so conductivity can be used. The dissolved salts in the circulating cooling water are in an ionic state and have certain conductivity. Therefore, the conductivity of the solution can be used to indirectly represent the content of dissolved salts. The conductivity measurement method is relatively simple, but some soluble Cl-, Br- plasma will be added after adding oxidizing bactericide to the system. At the same time, the conductivity will fluctuate due to material leakage in the system and other reasons. Therefore, for the circulating cooling water system, the input of oxidizing bactericide is generally regular, and material leakage is not frequent. Therefore, it is of certain reference significance to use conductivity to determine the concentration ratio of circulating water. The solubility of K+ ions in water is quite large and will not precipitate during operation. At the same time, the K+ of the supplemented water is basically stable, so the concentration ratio measured with K+ is more accurate.

Assuming that the quality of the replenishing water is stable and the effect of the fungicide on the conductivity is ignored, the concentration ratio and the conductivity are positively correlated, not proportional. It is also common to use conductivity to control the concentration ratio in production. Conductivity measurement is simple and reliable, requiring little instrument maintenance. In actual use, it is relatively stable.

We were going to measure the relationship between the concentration factor of an sulfate and the conductivity. Later we found that the concentration and conductivity are directly proportional in the low concentration area, but the relationship between the curves in the high concentration area is not proportional.

study* one time! Our conductivity is always high! We analyzed the reason and thought that one possibility is that the conductivity of concentrated water and external water is a bit high!