Engineered Plastic Cooling Tower Impervious to Water Chemistry and Environmental pH Factors

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Engineered plastic cooling towers are transforming the industry, eliminating the problems that plague galvanized metal cooling towers -- corrosion, leakage, maintenance costs and process disruptions caused by internal and environmental pH factors.

The "traditional" metal-clad cooling tower is under attack from all sides, particularly in the process industries where they are critical to maintaining temperature ranges for every process that creates heat. Today there are exorbitant maintenance costs and disruptions making the classic zinc galvanized sheet metal models outmoded.

The natural and mortal enemy of sheet metal is pH, usually on the low side. A high pH leads to excessive calcium and other ceramic-like deposits. When the pH of the cooling water becomes acidic (low), either because of external (e.g. atmospheric) elements, infiltration of process elements (e.g. material fines), or water treatment chemistry fluctuations, the veneer of zinc galvanizing used on most metal towers immediately begins to deteriorate. Because the zinc plating is thin (normally a scant 2.35 oz. per sq. ft), a pH lower than 6 will destroy this protective lining in a matter of months. At that point contractors are required to replace the zinc galvanizing by expensive coatings and repair any cavities and other damage that may have occurred. If the repair process is extensive, costly process interruptions are often required.

The inherent susceptibility of metal cooling to high and low pH led to the development of a new technology that is rapidly replacing the older one, particularly in the process industries: the engineered plastic cooling tower. The latest designs in corrosion-proof polyethylene tower technology come from Delta Cooling Towers of Rockaway, NJ; a company that has been in the business since the 1980's.

Ramcar, a major manufacturer of car batteries, uses an engineered-plastic tower to protect against the ravages of sulfuric acid at its City of Commerce, California, plant.

"We use relatively high concentrations of sulfuric acid (25-35%) mixed with the water used in our batteries," explains Larry Eslao, Chief Engineer. "This mixture gets very hot. With such a harsh mixture we would not want to use a metal clad tower, which would have a very short lifespan. We purchased this Delta plastic model because it is impervious to acid. We bought our present tower in 1987; it has proved to be virtually maintenance free."

When evaporation occurs in metal towers, scale is left behind, which can interfere with efficiency and requires expensive maintenance or acid cleaning. Over time, a sizable amount of dirt and scale deposits may collect in the bottom of the tower sump. These mineral deposits on galvanized steel often lead to corrosion under the deposits and the need for costly repairs and downtime.

On the other hand, the plastic cooling tower is also ideal for harsh environments. They are impervious to salt air and waste products that can often be found in the air in many industrial areas. They are also impervious to a variety of minerals found in extremely hard water. Because they are impervious to residual salts, evaporation cannot damage them and simply washing down the plastic surface with a hose can clean them up.

John Flaherty
Delta Cooling Towers, Inc.
Phone (800) BUY.DELTA (289.3358)
Fax 973.586.2243


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