Mass balance is a relationship between the amount of chloride ions and the amount of calcium ions in solution. The chloride ion is very soluble and will not precipitate even at extreme cooling tower conditions. Under certain conditions, the calcium ion will precipitate out of solution and form calcium scale.
By comparing the relative amounts of these two ions in solution, one can determine whether scale is accumulating or being removed. Chardon understands the importance of this metric and works to regulate it.
Cycles of concentration is typically calculated by dividing the concentration of chlorides in the tower water by the concentration of chlorides in the make-up water. The same concept of cycles can be applied to calcium hardness: divide the calcium hardness of the tower water by the calcium hardness of the make-up water.
Mass balance is calculated by subtracting the value for chlorides from the value for calcium hardness, or MB = CaH – Cl-.
Positive mass balance values indicate that there is more calcium in solution than would be predicted by simply cycling up. Typically, surplus calcium comes from dissolving deposits in the tower sump or on fill slats.
Negative values indicate a loss of calcium relative to the amount that there should be at the current number of cycles of concentration. This is an indication that calcium is precipitating out of solution and building scale on heat exchange surfaces.
Contact our cooling tower water treatment company for more information about these and other available cooling tower services.
