ProChemTech International Inc.’s chief chemist, Timothy Keister, has received a patent for his “Composition for Operation of Evaporative Cooling Towers with Minimal or no Blowdown.” The patent discloses the method and composition for operation of an evaporative cooling tower with minimal or no blowdown.
According to Keister, the method involves using sodium cation-exchanged softened water as make-up water for the cooling tower, treating the cooling water with the composition for control of corrosion and deposition, and using an effective biocide for control of biological growth within the cooling tower system. The composition is based on polysilicate. When dosed at recommended levels, it controls corrosion of system materials to generally acceptable levels despite the extremely corrosive environment resulting from cycling of softened make-up water to very high (4,000 to 25,000 mg/l) dissolved solids levels.
ProChemTech, Brockway, Pa., markets the technology under the names SofTek and ZBT (zero blowdown technology), with which it has accumulated several years of operating experience across the country. SofTek and ZBT are “green” technologies because they operate at high cycles of concentration, which substantially reduces cooling tower blowdown and fresh water use.
