There is now a proven, reliable alternative to costly and dangerous chemical treatment for your cooling tower is available with the “Dolphin System” by Clearwater Systems Corporation.
The Dolphin System provides water treatment by means of physical treatment rather than chemical treatment of your cooling tower water. The Pulsed Power technology was derived from the systems in use in the processed fruit juice industry providing product pasteurization. Although similar in design, the Dolphin uses a fraction of the power required for the systems associated with pasteurization, and is capable of maintaining near drinking water quality within the open tower system.
Since it is a chemical free water treatment, the Dolphin System prevents exposure to and migration of hazardous chemicals. The best way to prevent exposure to hazardous materials is to have them in your facility. Dolphin Technology resolves more than 10 OSHA and EPA concerns associated with chemical treatment. The Dolphin System further helps to reduce the environmental footprint of a facility by entirely eliminating chemical drift and its negative impact on air quality. In addition, by taking chemicals out of the condenser water, the blow-down (bleed) of a cooling tower is also free of chemical additives, thereby putting clean water into a sewer system or water treatment plant. This blow-down water can potentially be captured and re-used for secondary applications such as irrigation (assuming proper local/state permitting), further highlighting the environmental benefits of this timely green technology.
Bacteria Control Pulsed-power devices impart pulsed, high-frequency electrical energy into flowing water by inducing time-varying, pulsed electric fields 2, 400 times per second. Pulsing an electric field in this way generates low-frequency, non-ionizing electromagnetic radiation. This radiation has a much lower frequency than microwave radiation (even lower than radio waves) but has a demonstrable effect on microorganisms. In a typical cooling tower installation, each bacterium experiences more than 20,000 pulses. The damage is sufficient to inhibit reproduction but not sterilize the system. The bacteria can recover in a few days, but they remain inactive while they are recirculating through the pulsed-power system. Total bacteria counts under pulsed-power control typically average less than 1,000 colony-forming units per milliliter.
Corrosion Control. In corrosion control applications, pulsed power technology offers an advantage over chemical treatment with respect to copper. While copper is resistant to most domestic waters, it is subject to pitting by either microbial growth or high levels of oxidizing biocides (chlorine, bromine). Typical chemical regimes use a triazole as a copper corrosion inhibitor to protect the copper from the oxidizing biocide. Triazoles form a protective film on the copper surface and protect the underlying metal. However, triazoles are attacked by oxidizing biocides and, if they are at too low a level, can actually acerbate localized galvanic attack by only partially covering the metal. A pulsed-power system eliminates these sources of corrosion while maintaining biological control without oxidizing biocides.
Scale Control. When calcium carbonate (limestone) and other dissolved minerals are concentrated through evaporation, they reach the level of saturation. Saturation is the level of concentration above which the water can hold no more minerals. At saturation, the minerals must precipitate out as a solid, using a surface as a starting point (i.e., heterogenous nucleation).
Pulsed power technology makes tiny suspended dust particles alternative sites for mineral precipitation through heterogeneous nucleation by removing the particles’ surface charge. The dust particles become coated with the solid mineral material, thus acting as a relief valve for over-concentration of minerals (super-saturation). The dust particles are the preferred sites for precipitation over equipment surfaces for two reasons. First, the dust particles are so plentiful that minerals encounter them before they encounter the equipment surfaces. Second, the suspended particles travel with the flowing water and therefore do not have to overcome relative velocity, as they would between an equipment surface and flowing water. The mineral-coated powder produced by the pulsed-power system is harmless and non-sticking.
