The compounds including nitrite and nitrate are used as metal inactivators in closed circuit cooling tower systems. These compounds as an anodic inhibitor prevent corrosion with formation of an impermeable and stable film on the metal surface; also the role of borate in this compound as a neutralizer is important. This solution prevents the corrosion of various metals such as aluminum, tin and ferrous metals, especially steel to a large extent. The use of Mitreh 958 solution in the water treatment of closed circuit cooling towers in terms of solutes is also very important. It should be noted that the presence of chlorine and sulfate ions in high amounts causes the solution to be inactivated.
Calibration of Using Mitreh 958 Solution:
In order to prevent the formation scale and corrosion in closed circuit cooling tower systems, the amount of solution consumption varies depending on hardness of the inlet water.
To calculate more accurately, consider the following:
1- Sample analysis of system feed water
2- Ensuring that the system is clean (in terms of scale and other contaminants)
3- The amount of water circulating and the volume of water consumed (make-up)
4- Complete system monitoring and field inspection of various parts of the circuit in terms of corrosion
Some Physical Properties of the Solution:
|Liquid||Physical state||8.3 – 8.9||pH|
|Colorless||Color||95 – 97||Boiling temperature range (˚C)|
|Mild odor||Odor||-1 – 0||Freezing temperature range (˚C)|
|1.021 – 1.028||Density at 20˚C (gr⁄ml)||Dissolves rapidly||Solubility in water|