Plastics
COOLING TOWERS: BIGGER AND BETTER IN PLASTICS
Factory-assembled towers boast competitive advantages over those that are field-erected
Cooling towers – bastions of wood, fiberglass, steel or concrete – could someday go the way of galvanized pipe, aluminum cable and other equipment that has been materially altered by plastics. It's not that plastic cooling towers are new; on the contrary, they have been around for more than 30 years. Rather, it is the fabrication of these plastic structures in larger sizes that is expected to pave the way for them to make greater inroads in the chemical process industries (CPI). Plastics are considered ideal materials of construction for cooling towers because they are durable and resist corrosion. But factory construction of plastic towers has until now been limited to a capacity of about a couple hundred cooling tons – too small for many industrial applications, says John Flaherty, president of Delta Cooling Towers, Inc. (Fairfield, N.J.), which pioneered the development of plastic cooling towers in the 1960s. Today, however, with advances in engineering resins and molding techniques, Delta can assemble towers to accommodate almost any size specification. Recently, the company introduced its modular TM Series cooling tower, which is molded from high-density polyethylene in capacities up to 2,000 cooling tons. Cooling towers are properly sized by cooling tons. One ton of evaporative cooling is equal to 15,000 Btus/h. Cooling is facilitated by water, which picks up the plant's heat load and transfers it to the cooling tower, which, in turn, transfers that heat through evaporation to the atmosphere via fan exhaust. The same amount of cooling tons can be achieved at different water flowrates, or gallons per minute, by varying the range of cooling (temperature in minus temperature out). For larger-tonnage applications, multiple modules are supplied, and, if necessary, individual modules can be
Factory-assembled towers boast competitive advantages over those that are field-erected
Cooling towers – bastions of wood, fiberglass, steel or concrete – could someday go the way of galvanized pipe, aluminum cable and other equipment that has been materially altered by plastics. It's not that plastic cooling towers are new; on the contrary, they have been around for more than 30 years. Rather, it is the fabrication of these plastic structures in larger sizes that is expected to pave the way for them to make greater inroads in the chemical process industries (CPI). Plastics are considered ideal materials of construction for cooling towers because they are durable and resist corrosion. But factory construction of plastic towers has until now been limited to a capacity of about a couple hundred cooling tons – too small for many industrial applications, says John Flaherty, president of Delta Cooling Towers, Inc. (Fairfield, N.J.), which pioneered the development of plastic cooling towers in the 1960s. Today, however, with advances in engineering resins and molding techniques, Delta can assemble towers to accommodate almost any size specification. Recently, the company introduced its modular TM Series cooling tower, which is molded from high-density polyethylene in capacities up to 2,000 cooling tons. Cooling towers are properly sized by cooling tons. One ton of evaporative cooling is equal to 15,000 Btus/h. Cooling is facilitated by water, which picks up the plant's heat load and transfers it to the cooling tower, which, in turn, transfers that heat through evaporation to the atmosphere via fan exhaust. The same amount of cooling tons can be achieved at different water flowrates, or gallons per minute, by varying the range of cooling (temperature in minus temperature out). For larger-tonnage applications, multiple modules are supplied, and, if necessary, individual modules can be