Tower Systems For Cooling And Organic Solvent Removal
Cooling towers use either evaporation or air to remove heat and cool water to a desired temperature. They’re an integral part of the function of oil refineries, petrochemical and other chemical plants, thermal power stations and structural HVAC systems that need circulating water to maintain proper operating temperatures. Over 1,500 industrial facilities cool their plants using such a system. A large power plant might have pipes as large as 15 feet in diameter transferring hundreds of thousands of gallons per minute.
These towers range in size from relatively small roof-top units to hyperboloid configurations as large as 660 feet tall and 330 in diameter and rectangular units that measure 260 feet in length and are more than 130 feet tall.
As a vital part of tower maintenance, it’s important to avoid the accumulation of scale, biological growth, corrosion, and deposits that can reduce its energy efficiency by 5% or more.
Cooling tower shells formed of seamless plastic never rust, flake, chip, peel and will not require painting or any protective coatings. Corrosion of metal towers in outdoor applications is a constant problem. Even galvanizing and other metal treatments are temporary solutions that only delay the inevitable. Using a one-piece plastic shell eliminates all of the panels, rivets and fasteners that are likely to fail over time.
One significant benefit of cooling towers is their positive impact on the environment. They recycle over 98% of water that would otherwise be wasted.
Removal of organic solvents from water by tower systems is handled in two ways. Aeration is a process by which air or oxygen is added, and air stripping describes the removal of gas. The latter alternative is the preferred water remediation technology for eliminating not only organic solvents but chlorinated hydrocarbons, fuel/gasoline hydrocarbons, degreasers, and certain other volatile organic chemicals (VOC). VOC removal can also include radium, uranium and other contaminants.
Air strippers for removal of organic solvents provide a packed bed of plastic media to create a large surface area. The water flows down and air flows up, taking the chemicals with it and exiting at the top of the stripper.
Removal of organic solvents by means other than the packed bed technology, such as bubble aerators, perforated trays and membranes, are effective to a degree, but packed columns offer the most economical operation – especially when the flow of incoming water exceeds 50 gallons per minute.