THE CHALLENGE
Samples of scale deposits from a Client’s Cooling Tower were sent to evaluate the effectiveness of Enviro-Syn® HCR-IND treatment options in dissolving solids. The initial formation of the deposits was identified due to increased pressure and clogging of the tower sprayers. The cooling water normally operates between 35–55 degrees Celsius.
MAXIMUM SOLUBILITY TEST PROCEDURE
The scale samples were crushed and passed through a mesh-10 sieve. To determine maximum solubility, 3–5 g of the sample were added to a beaker containing 50 ml of the test fluid. Enviro-Syn® HCR-IND reacted with the deposit for 6 hours at 35 °C on a hot plate, with a magnetic stir bar at 190 rpm to ensure proper mixing. Afterward, the mixture was vacuum-filtered using a P8 filter paper to determine the remaining mass of the scale.
RESULTS
Table 1 shows the X-ray diffraction (XRD) results of the sample, identifying a predominance of magnetite. Maximum solubility results are summarized in Table 2, with the Enviro-Syn® HCR-IND data showing excellent solubilization potential.
| Weight % | |
| Magnetite | 100 |
| Total % | 100 |
Table 1. Summary of XRD results from the scale sample
| Product | Concentration | Duration (h) | Maximum Solubility |
| Enviro-Syn® HCR-IND | 100 % | 6 | 75.1 % |
| HCR-IND | 75 % | 6 | 75.7 % |
| HCR-IND | 50 % | 6 | 54.1 % |
Table 2. Maximum solubility test for 6 hours at 35 °C with stirring
RECOMMENDED TREATMENT PLAN
Based on the results, a recirculation procedure was implemented using Enviro-Syn® HCR-IND at 100%, in an amount equivalent to 20% of the total cooling tower water volume, in a closed loop, isolating process equipment. The solution was recirculated for two hours, which was sufficient to restore normal operating pressure. This program was implemented bimonthly by this client.
CONCLUSIONS
Tests indicate that Enviro-Syn® HCR-IND is effective in removing scale deposits from the cooling tower without causing damage to the system. This study reinforces the applicability of Enviro-Syn® HCR-IND as an efficient and safe solution for scale treatment in cooling towers.
