TOWER PERFORMANCE–Keep the cooling tower clean and water dis- tribution uniform to obtain continued maximum cooling capacity.
The capacity of a cooling tower to cool water to a given cold water tem- perature varies with the wet-bulb temperature and the heat load applied to the cooling tower.
As the wet-bulb temperature drops, the cold water temperature also drops. However, the cold water temperature does not drop linearly with the wet-bulb temperature.
A cooling tower will not control heat load. The flow rate of water circulated through the cooling tower will determine the temperature range of cool- ing in conjunction with a given heat load. The hot water and cold water temperatures will increase with higher heat loads.
HOT WATER DISTRIBUTION SYSTEM–Maintain uniform water distribu- tion at the nozzles (uniform spray cone). The amount of water circulated should approximate the contract requirements and the nozzle pressure should be kept constant. Lower pressures may indicate excessive losses in the piping system and/or insufficient pump capacity; greater pressures might indicate clogged nozzles and/or overpumping. If a greatly reduced water flow rate is desired, it may be advisable to change nozzle sizes to obtain the desired pressure and maintain proper water distribution. An SPX Cooling Technologies engineer can advise minimum and maximum flow rates for even distribution.
COLD WATER COLLECTION BASIN–A suitable depth must be maintained to keep the pumps from pulling air into the line. The amount of “make-up” water required to keep the water in the collection basin at the required depth depends upon the “evaporation loss” and “blowdown” .
FAN DRIVE–When using two-speed motors, allow a time delay of 20 seconds minimum after de-energizing the high-speed winding and before energizing the low-speed winding. Tremendous stresses are placed on driven machinery and motors unless the motors are allowed to slow to low-speed RPM or less before the low-speed winding is energized.
COLD WEATHER OPERATION–During periods of low temperature op- eration, 35°F to 40°F or below, ice will form on the relatively dry parts of the cooling tower that are in contact with the incoming air. Primarily, this includes the air inlet and adjacent structural framing. Your understanding of
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