Evaporative Cooling; On, Off and Overflow

Evaporative systems are one variety of condenser type which may be installed as part of an industrial cooling system.

The role of an evaporative condenser is to convert refrigerant from a heated vapor to a cooled liquid, or to cool some type of closed loop. The refrigerant is contained within a closed circuit, and when water is sprayed on the exterior surface of the refrigerant tubing, cooling takes place according to the principles of heat rejection.

Benefits of Evaporative Condensers

Evaporative condensers have potential advantages over a cooling tower, under the right circumstances. They may consume less electricity; they take up less floor space; and because they have fewer components, they are easier to install and maintain.

Maintaining Water Level

Evaporative condensers run on small volumes of water, which means there’s a narrow acceptable margin in terms of the water level. Basin float level controls are important, especially in circumstances when the condenser runs intermittently.

Under such circumstances, when the spray pump is off the entire volume of the water in the tower accumulates in the basin. When the spray pump comes on, the water level in the basin drops as water goes up into the tower and circulates; so the level controls admit more water to maintain the prescribed level.

Secondary level controls control the water on/ off filling the tower basin’ these are designed such that when the tower spray pump shuts off, the extra volume of water which was added doesn’t overflow the basin. If these controls are not set properly, water and chemical can overflow to the drain. This overflow may not be noticed, but it should be avoided since it wastes water as well as treatment chemicals. By sending chemicals down the drain, it interferes with the prescribed balance of chemicals for optimal performance.

In other words: If the conductivity in an evaporative condenser never seems to reach the set point, it may be because the tower level controls are set incorrectly.

Troubleshooting and Solutions

• Put a paper towel over the drain port. If it gets wet, you know the system is overflowing.
• Adjust level controls .
• Raise the overflow in the tower basin.

Operating Evaporative Controllers

Evaporative controllers rely on a small volume of water to function. While simple, they are sometimes easy to operate… or they can be a challenge. If you are struggling to keep chemicals in balance, be sure to consider mechanical options as you troubleshoot. As always, hit us up at Chemtex if you have any questions.