SPX Cooling Technologies Marley MD specifications Electric Basin Heaters, Indoor Storage Tank

Marley / MD CoolingTower / Engineering Data: Freeze Prevention

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When the ambient air temperature falls below 0°C, the water in a cooling tower can freeze. Marley Technical Report #H-003“Operating Cooling Towers in Freezing Weather” describes how to prevent freezing during operation. Available at spxcooling.com or ask your Marley sales representative for a copy.

During shutdown, water collects in the cold water basin and may freeze solid. You can prevent freezing by adding heat to the water left in the tower—or, you can drain the tower and all exposed pipework at shutdown.

Electric Basin Heaters

An automatic basin water heater system is available consisting of the following components:

•Standard weatherproof (IP55) enclosure, rating depending on model and minimum expected winter temperature.

•Ratings are in kW for specified ambient temperature.

For lower ambient temperatures refer to SPX engineering for advice.

•Standard electircal supply is 380/415 V 3ph (220/240V 1 ph available as extra cost option).

•Heater has an integral thermostat, set point nominally

3°C but adjustable to suit operating requirements.

Heater components are normally shipped separately for installation by others.

Note: any exposed piping that is still filled with water at shutdown—including the makeup water line—should be electrically traced and insulated (by others).

Indoor Storage Tank

With this type of system, water flows from an indoor tank, through the load system, and back to the tower, where it is cooled. The cooled water flows by gravity from the tower to the tank located in a heated space. At shutdown, all exposed water drains into the tank, where it is safe from freezing.

The amount of water needed to successfully operate the system depends on the tower size and GPM and on the volume of water contained in the piping system to and from the tower. You must select a tank large enough to contain those combined volumes—plus a level sufficient to maintain a flooded suction on your pump. Control makeup water according to the level where the tank stabilizes during operation.