Water Management is an essential part of many industries, for which clarifier and settlement tanks play a crucial role. Whether it is for a pharmaceutical site, a mine or a wastewater treatment plant, ensuring correct and effective processing is the cornerstone of this sector and any damage to these pieces of equipment can have significant consequences.
Common problems
By their very nature, clarifier and settlement tanks are susceptible to three main issues: corrosion, erosion and chemical attack. Of course, steps are taken to reduce the impact these issues have, simply by controlling their operation. For instance, the flow speed from inlet pipes is kept low. This minimises the amount of turbulence and disruption of the settled and coagulated solids. However, effective operation still cannot eliminate these problems.
Whether these problems arise in the form of deteriorated concrete; eroded and corroded metalwork, or failed expansion joints, the appropriate solutions must be able to withstand the operating conditions and demonstrate long-term resistance to the aforementioned effects. Belzona has been involved with maintenance for clarifier and settlement tanks for over 65 years and therefore, has significant experience in providing long-lasting repair and protective materials.
Settling on a clear solution
One such example includes a clarifier at a wastewater plant in Houston, USA. This clarifier had been operating without any form of protective coating since its installation and when inspected in 2013, they realised the significant erosion damage to the concrete structure. Accentuating this even further were the rigorous cleaning processes. The customer was looking for a long-term repair in lieu of repairing it every 2-3 years as they have done in the past. Furthermore, the asset owner required any solution to accommodate for the cleaning procedures. With damaged concrete and no coating, the trough was hard to keep clean. In fact, it was taking 2-3 times longer than when new.
Notably, the Maintenance Manager for the facility was already familiar with Belzona systems. Having specified their use elsewhere in the plant and having a great deal of experience with the local Distributor, provided assurance that the proposed solution would work well.
Application in progress
During the designated downtime, scaffolding was erected around the circumference of the clarifier, allowing easy access for the maintenance crew. Using Belzona 4131 (Magma-Screed), which is easy to apply over large areas, the damaged concrete was returned to its original profile. Far stronger than concrete, this actually enhanced the erosion resistance of the clarifier. However, as a further protective measure and to facilitate easier cleaning, Belzona 5811 (Immersion Grade) was applied within the trough. Overall, this system provided a long-term solution, designed for immersed operation whilst providing outstanding corrosion and chemical resistance.
Cost-effective and time-saving
The application window available for the maintenance was simply three days. In comparison to competitor systems, which would have required shutdown for over a week, the Belzona repair was able to be carried out over the long weekend specified by the facility. In addition to the quick turn-around, these materials have a proven track record within other areas of the treatment plant. Altogether, the Maintenance Manager was very satisfied with the repair as it was cost-effective and saved time. This application is still faring well in service to this day.
For more information about Belzona’s range of solutions for the Water and Wastewater Industry, visit: https://www.belzona.com/en/industries/wastewater.aspx
