October 2015 – One of the simplest and most cost-effective ways in which to extend the life of a cooling tower, improve heat transfer efficiency and reduce maintenance downtime, is to upgrade the cooling tower’s fill media to components constructed out of robust and non-clogging materials such as Polypropylene (PP), PVC or stainless steel.
Fill is a critical component in the heat transfer process of evaporative cooling systems, acting as the medium over which the hot water is distributed as it is being cooled. Fill’s primary function is to put as much water surface area in contact with as much air for the longest amount of time possible.
When compared to other cooling tower components, fill is also the most susceptible to wear and tear due to the almost constant exposure to water at high temperatures.
Comments Roger Rusch, CEO of IWC, “In older cooling towers, fill media was typically constructed out of wood or asbestos cement. Wood deteriorates rapidly when compared to modern fill materials such as Polypropylene, PVC and stainless steel and we all know the dangers associated with asbestos containing materials. Upgrading a cooling tower’s fill media to these more modern and robust materials can result in significant improvements in heat transfer efficiency.”
Different types of fill-designs utilised in cooling tower applications the most common are splash and film fill packs. Film packs consist of narrow, closely-placed surfaces over which the hot water spreads, forming a thin coating that comes into contact with air.
This type of fill media creates a large surface area on which the hot water disperses itself as a thin film that interacts with the air travelling through the tower. In contrast, splash-fill packs are made up of layers of horizontal splash trays into which the water flows, breaking into small droplets. Here, the exchange area for cooling is provided by water droplets, and heat exchange occurs on the surface of these droplets.
Says Rusch, “Film packs constructed out of corrosion-resistant polypropylene or PVC are most commonly used in smaller industrial cooling towers and cooling towers used in HVAC applications where make up-water quality is good i.e. has low levels of both suspended and dissolved solids.
In cooling tower applications where the recirculating water quality is poor and has high solids content, the non-clogging splash grids or splash tubes are well suited. In high temperature application where the hot water temperatures exceeding 60 degC, metallic splash grids such as X- Grids are advisable.
About IWC
IWC, originally founded in 1986 as Industrial Water Cooling, are at the forefront of cooling tower technology, delivering world-class, fully-integrated solutions across all industries, from mining; power generation and petrochemical; water and sanitation; to light industrial.
IWC have been active in the refurbishment of cooling towers and bulk-air air coolers of all makes, types and sizes over the past two decades. This includes the installation of fill material, drift eliminators, spray systems and nozzles as well as fan mechanicals.
IWC have successfully undertaken more than 80% of all natural draft refurbishment work in southern Africa. Clients include heavyweights such as Eskom, Sasol, ArcelorMittal and Foskor.
For more information, visit: http://www.iwc.co.za or contact IWC on +27 (0) 11 466 0699