Cooling towers are an integral part of many processes. Maintaining a system and keeping it in optimal working order offers a lot of benefits. What one may not realise is that airborne dirt can get into the water in a cooling system and restrict the free movement of liquid. Dirty and hard water can lead to the build-up of scale and contaminants.
Using a mechanical filtration system along with a water treatment program will help in boosting water quality. This, in turn, will reduce energy costs and result in efficient cooling.
How to successfully filter cooling tower water
A typical 200+ cooling tower can operate over 1000 hours annually and could collect over 500 lbs. of dirt in the water supply from dirt in the supply as well as airborne dust. Warm conditions usually encourage bacteria growth. Using chemicals to retard bacterial growth doesn’t always work. If a mechanical filtration system is used, it can make a big difference.
The ability to filter water in a cooling tower depends completely on the system’s design. A good design comes about when a designer understands what problems are being faced and what contaminants have to be filtered.
There are a few methods which can be used to filter cooling tower water. These have to be used in conjunction with pump suction strainers as they are the first step in the filtration process. These strainers are located on outlets to prevent sticks and other debris from getting into the system.
Pump suction cleaning is the commonly used method, which prevents solids from accumulating in the unit basin. If there is no mechanical system in place, basin cleaning has to be done by hand by a maintenance crew. This is not efficient and requires constant work. This work can be done by using nozzles and using pressure to clean up sediment.
Full flow and side stream filtration are two methods which offer direct protection to the heat exchanger and the chiller but don’t work well to prevent the accumulation of dirt in the basin. Filters are used to handle dirt and have to accommodate the prescribed flow rate.
These are just two methods which are used to keep a cooling tower water filtration system working well. Depending on need, systems can be designed to do this job efficiently, and the use of screens and filters make the job easier.