ProChemTech International Inc. received a patent relating to the operation of evaporative cooling towers.
Timothy Keister, CWT, the chief chemist at ProChemTech
International Inc., Brockway, Pa., has received U.S. patent No. 7,595,000 for “Operation
of Evaporative Cooling Towers with Minimal or No Blowdown.”
The patent discloses a means to reduce blowdown - water
wasted to sewer - from operation of evaporative cooling towers. The technology
involves softening of the makeup water, use of a specific chemistry to control
the high corrosivity of concentrated soft water, bypass filtration, and the use
of bromine as a biocide for microbiological control. The combination of this
technology with the company’s side-stream electrolytic bromine generator for
control of microbiological growth reduces cooling tower fresh-water needs while
eliminating use of toxic biocides, according to ProChemTech.
Economic analysis shows a typical payback of less than one
year on required equipment and reductions of up to 25 percent in fresh makeup
water use and a 70 percent or better reduction in water discharge to sewer, the
company says. The technology has been in operation for more than a year at the
Tempe Transportation Center Building in Tempe, Ariz.
ProChemTech says it anticipates the technology will be
especially applicable for use in water-short areas of the country and where
high hardness makeup water sources limit the cycles of concentration that can
be obtained in an evaporative cooling tower.