Posted on: March 10th, 2022 by Apex Team

Cooling Tower & Chiller Descaling

An evaporative condenser is designed to condense a refrigerant gas and a fluid cooler cools process water contained on the inside of the unit’s tubes. The water is circulated from the basin located at the bottom of the unit up to the top and distributed by spray nozzles to optimize tube cooling coverage.

The spray nozzles will distribute the water evenly over the tube bundle located midsection on the inside of the unit. The fan on the top of the unit is used to pull air through the side louvers, enhancing evaporation, resulting in further cooling of the water during its descent to the basin. 

Scale deposits form on the exterior tube surfaces of a heat exchange coil, which acts as an insulating barrier. The ultimate result is inadequate cooling, overworked machinery, and expensive, inefficient operation. Scale also restricts the spray coverage of the nozzles at the top of the unit, resulting in the water not flowing over the entire tube surface. This will cause channeling and further minimizing cooling capacity. A scaled evaporative condenser or fluid cooler cannot efficiently cool the water or condense the refrigerant gas inside the tubes

Studies have shown a scale thickness of only 1/32” will reduce the heat transfer coefficient of an evaporative condenser by approximately 16%! Reduction of efficiency directly relates to added energy consumption and higher energy bills.

What is a Cooling Tower?

The basic principle of a cooling tower is to cool the water that has picked up heat generated by equipment within the facility. The operation begins in the tower basin where the cooled water is pumped out into the facility and utilized for cooling the equipment on the tower system. 

As that equipment is cooled, the water picks up the heat and returns to the top of the cooling tower. The hot water is distributed onto a hot deck or through the sprayer nozzles that evenly distribute it over the tower fill media. The tower fill media is designed to increase surface area, as well as contact time between air and water. This enhances evaporation and allows further cooling of the tower water. The water then falls into the tower basin where it is then pumped back into the facility continuing to cool the equipment.

Scaling within a cooling tower can restrict the water distribution of spray nozzles, reduce the water flow through the openings of a hot deck and restrict the airflow within the tower. All of these conditions will result in diminished cooling capacity and inefficient operation of the associated equipment on the cooling tower system.

Descaling Chillers & Condensers with RYDLYME

The following is a detailed procedure for cleaning a cooling tower system or an evaporative condenser/fluid cooler with RYDLYME. To ensure a successful cleaning, please contact Apex Engineering Products Corporation for technical assistance prior to starting the cleaning procedure.

  1. Close the water valve-to-tower basin.
  2. Turn off all chemical or non-chemical water treatment, conductivity meters and pH meters.
  3. It is recommended that all loose water scale, lime, mud, rust and other foreign matter be manually removed from tower basin prior to starting the cleaning.
  4. Lower the water level in the tower basin to a point where the pump can maintain circulation without cavitation and close the bleed-off valve.
  5. It is recommended that the fans be turned off during the cleaning.
  6. Determine the proper amount of RYDLYME to be added to the system. Please note that the amounts recommended in the chart are just guidelines and that your application may require 2-4 times the chart amount, depending on the severity of the deposit build-up in your system.
  7. To minimize excessive foaming, you may slowly add required amount of RYDLYME to the tower basin.
  8. The bubbling and foaming you will observe is a natural reaction of the RYDLYME dissolving the water formed mineral deposits within the system.
  9. Once the RYDLYME is in the tower system, allow it to circulate. Start charting your pH readings or performing calcium spot tests to measure the effectiveness of the RYDLYME solution as the cleaning solution expends prior to the completion of the recommended circulation time, there is more scale in the system. It is recommended that you repeat steps 6-9 to complete the cleaning.
  10. It is recommended that the RYDLYME cleaning solution be cycled out of the system to prepare it for normal operation. At this time, strainers should also be removed, inspected and cleaned as well.
  11. Once the cleaning material has been cycled from the tower system, turn your conductivity, pH meters or any other equipment back on. Return the make-up water and bleed off valves per the manufacturer’s recommendations. Lastly, resume normal system operation. 

CAUTION: RYDLYME is non-corrosive, but the application of RYDLYME may expose pre-existing under deposit corrosion (pitting, holes or similar damage) that can result in leaks in pipes, equipment or systems.

View more information in PDF.

RYDLYME The World’s Leading Biodegradable Descaler

For more than 80 years, RYDLYME has been the most trusted brand for removing scale from boilers, cooling towers, heat exchangers, condensers, chillers, and so much more. If you have further questions pertaining to the effectiveness of “The World’s Leading Biodegradable Descaler,” RYDLYME, please feel free to contact our main office.