The principle of circulating water scale inhibitor should first start from the formation of scale. From the process of water scale such as calcium carbonate, is slightly soluble salt crystallization precipitation from solution of a process, the crystallization dynamics view, the process of crystallization is the crystal core, forming a small amount of particles, then the tiny crystal in the solution due to thermal motion (Brown Movement) constantly collision, and metal wall also constantly collision, collision result provides the opportunity of crystal growth, make small crystal constantly into large crystal, that is to say, formed the scale layer covering heat transfer surface. From the crystallization process of calcium carbonate, if some agents can be added to destroy its crystallization growth, the purpose of controlling the scale formation can be achieved.

The circulating water scale inhibitor can be directly added, or it can be diluted in any proportion. The dilution concentration of the circulating water scale inhibitor standard liquid should not be less than 10%, and the diluted circulating water scale inhibitor must be fully stirred to ensure uniform mixing.

In order to ensure the recommended dosage injection system, the following two standards can be formulated according to the actual conditions:

1. Calibrate and determine the actual output of the dosing metering pump, and first calculate the concentration of the matched circulating water scale inhibitor according to the inlet water flow rate and the recommended dosing dose. According to the volume of preparing circulating water scale inhibitor, then calculate the amount of standard liquid needed for preparing circulating water scale inhibitor.

Concentration (g / L) = standard injection per unit time (g / h) / actual output of dose metering pump (L/h)

Where: standard fluid injection per unit time (g / h) = water flow (T / h)×added dose (g / T, ppm)； Quantity (kg) = concentration (g / L)×volume (L) / 1000 (g / kg)

2. Determine the circulating water scale inhibitor according to the concentration of the standard liquid, calculate the output of the required dosing metering pump according to the system, and adjust the output of the metering pump.

Concentration of circulating water scale inhibitor (g / L) = amount of pharmaceutical standard solution (kg) / volume (L)×1000 (g / kg)

Actual output of dosing metering pump (L/h) = unit time (g / h) / concentration (g / L) Where: standard fluid injection per unit time (g / h) = water flow (T / h)×added dose (g / T, ppm)