By the time you read this article, I am sure we will be behind the dog days of summer and every one of us will have forgotten those hot and humid days when our process cooling tower temperature just wouldn’t budge even a degree, irrespective of what we tried. Cooling towers and fin fans are the main heat sinks at plants; any bottlenecks there cascade the problems upstream, impacting process throughput and yield. This article sheds some light on cooling towers; a future column will address fin fans and their efficiency points.
Cooling towers come in several different configurations. Although the principles of the heat rejection mechanism are the same, every cooling tower design and configuration is unique and specific. Hence, the first and foremost requirement before beginning any assessment is to review the cooling tower’s design documentation. The design should provide information on heat duty (cooling tower tons), water flow rate, temperature difference (between supply and return water temperature), air flow required and approach to wet-bulb temperature. Changing any one of these parameters can impact significantly the operating performance of the cooling tower and in most cases will degrade efficiency or the ability of the cooling tower to meet design requirements.