The Dolphin system leverages pulse-power technology to impart a broad spectrum of electro-magnetic fields into the flowing cooling tower water. This removes the static charge from naturally-occurring particles and results in:
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Water based evaporative cooling systems reject heat by evaporation of water. This process occurs within a cooling tower. Water exits the cooling tower as a vapor leaving behind the naturally occurring dissolved minerals present in the water. Concentration of dissolved minerals increases over time. Upon sufficient concentration, dissolved minerals such as calcium carbonate (i.e., limestone) become solid in a process known as precipitation. The Dolphin changes the form of precipitated solids from hard lime scale found on equipment surfaces to a harmless powder flowing with the cooling water.
The Dolphin System accomplishes this change by “activating” naturally occurring, small-suspended particles in the water. Small suspended particles exist in large quantities in all city water or well water that is used as a source of make-up water to a cooling tower. Under Dolphin System treatment, suspended particles (suspended meaning that they neither sink nor float because of their small size) act as seeds for precipitation of dissolved minerals. The Dolphin System’s pulsed fields activate the suspended particles by removing their naturally present static electric surface charge. Once the surface charge is removed, precipitation of dissolved solids occurs preferentially around the “activated” particles rather than on equipment surfaces. The resultant product of this process takes on a powdery appearance and character and is called “Dolphin powder”.
Provided sufficient concentration of dissolved minerals is maintained Dolphin powder, consisting mainly of calcium carbonate, will continue to grow either by coating or adhering to the suspended seed particles. These coated particles or powder can be easily removed from a cooling tower basin by manual means, filtration, or centrifugal separation. The concentration of Dolphin Powder is typically about 15% of normal blown-in dirt in a cooling tower.
In the aerated water flow of cooling systems metals used in the construction of these systems will naturally corrode. Inhibiting the rate at which these metals corrode is an objective of any water treatment program. Corrosion inhibition with the Dolphin System is achieved by formation of cooling water chemistry where calcium carbonate is concentrated sufficiently for precipitation to take place. This water chemistry (i.e. saturated with calcium carbonate) creates a benign corrosion environment for the materials of construction associated with cooling systems. Water chemistry control is obtained by use of a conductivity control device. Conductivity controllers are commonly used in water based evaporative cooling systems. The combination of saturated water chemistry established by conductivity control and freedom from equipment scale by use of the Dolphin System provides effective corrosion inhibition without the need for chemical additives.
The Dolphin prevents the source of other corrosion attacks, such as microbial influenced corrosion arising from formation of biofilms and under deposit corrosion caused from formation of permeable or semi-permeable deposits on equipment surfaces. Under Dolphin System treatment, these conditions are absent and therefore these sources of corrosion are eliminated.
The Dolphin System utilizes two independent methods of controlling microbial populations in cooling systems: encapsulation and electroporation.
Dolphin powder incorporates many of the free-floating (i.e., planktonic) bacteria found in the cooling water flow of water based evaporative cooling systems. Without Dolphin System treatment, bacteria are repelled by the suspended particles due to the fact that nearly all tiny particles have similar static electric surface charges in water. Once water travels through the Dolphin System, repulsion of suspended particles, including bacteria is eliminated; therefore, bacteria are attracted to other suspended particles, such as Dolphin powder, by natural forces (i.e., van der Waals forces) and become incorporated in Dolphin powder. Bacteria that have become trapped in Dolphin powder have limited ability to gain nutrients from the cooling water or excrete wastes thus reducing the bacteria’s ability to reproduce.
The Dolphin System’s pulsed, high frequency electromagnetic fields damage planktonic bacteria by creating small “pores” in their outer membrane. This condition weakens the bacteria and inhibits their ability to reproduce.
The combined effect of these two methods; encapsulation and electroporation, control microbial populations to very low levels eliminating the need to routinely add any chemical biocide products.
Microbial life is encapsulated into the forming powder, preventing it from reproducing. Microbes have a 24-48 hour life span. Any microbes not captured in the forming powder are “zapped” by the Dolphin’s pulsed fields, where their life span is spent repairing membrane wall damage rather than reproducing.
Biofilm or Slime
Bacteria may form a biofilm or slime layer on equipment surfaces. Biofilm consists of a slimy bacterial secretion that forms a protective canopy for the bacteria beneath. It is very slimy to the touch, four times more insulating to heat transfer than mineral scale, and is the primary cause of microbial influenced corrosion. The bacteria that live in a biofilm adhering to an equipment surface are called sessile bacteria and can represent 99% of the total bacteria in a system. The Dolphin System eliminates the slime layer through the process of nutrient limitation. All the living organisms in a cooling tower depend on each other for their food supply. In Dolphin treated systems planktonic bacteria populations are kept quite low. Thus, nutrients sourced from planktonic bacteria are reduced and a biofilm cannot be sustained.