SOLVENTS AND DETERGENTS
There are several uses for solvents and detergents in the ordinary maintenance schedule of air-cooled tin- coil condensers, evaporator coils, permanent-type air filters, and fan blades. In most instances, a high-pres- sure spray washer is used to clean the equipment with detergent, then a high-pressure spray rinse is used to clean the unit being scrubbed. The pump is usually rated at 2 gallons/minute at 500 pounds/inch2 of pres- sure. The main function is to remove dirt and grease from fans and cooling surfaces. It takes about 10 to 15 minutes for the cleaning solution to do its job. It is then rinsed with clean water.
Using the dipping method cleans permanent-type filters. Prepare a cleaning solution of one part deter- gent to one part water. Use this solution as a bath in which the filters may be immersed briefly. After dip- ping, set the filter aside for 10 to 15 minutes. Flush with a stream of water. If running water is not available, good results may be obtained by brisk agitation in a tank filled with fresh water. When draining the solution used for cleaning purposes, be sure to follow the local codes on the use of storm sewers for disposal purposes. Proper disposal of the spent solution is critical for legal operation of this type of air-conditioning unit.
Another more recent requirement is the use of asbestos in the construction of the tower fill. If discovered when inspections are conducted, make sure it is replaced with the latest materials. The older towers can be- come more efficient with newer fill of more modern design.
Cooling-tower manufacturers design their units for a given performance standard and for conditions such as the type of chiller used, ambient temperatures, location, and specifications. As a system ages, it may lose efficiency. The cleanliness of the tower and its components are crucial to the success of the system. An un- attended cold-water temperature will rise. This will send warmer water to the chiller. When the chiller kicks out on high head pressure, the system may shut down. Precautions should be taken to prevent shutdown from occurring.