Cooling Towers for Process Cooling

Often times in an industrial plant when a process needs some measure of cooling, the obvious, but sometimes overlooked solution is to simply use a cooling tower in lieu of domestic water, river or lake/pond water, or rob water from your chill water loop.

The following is a list of the Dos & Don'ts of cooling tower process loops.

> Make sure your cooling tower or close circuit cooler is properly sized to handle your process cooling load and temperature range.

• Performing an engineered load audit and system design upfront is money well spent. Such an audit / design ensures that you purchase the correct equipment and gets your process into operation quicker.

• Make sure the fill media in your cooling tower is rated to handle the process temperature range. In some cases, special fill media may be required.

• Identify any process chemicals that may contact your cooling tower/cooler. Make sure your equipment’s construction components are compatible.

> Cooling tower/cooler location is critical.

• Locate your evaporative cooling equipment away from buildings and walls to prevent the possibility of air short-cycling. Hot discharge air short-cycling back into the tower inlet will drastically decrease the tower’s efficiency.

• Locate your equipment in a clean area away from dusty or contaminated environments. Anything that’s in the air will end up in your cooling tower basin causing maintenance and performance issues.

• When possible, locate cooling tower at a higher elevation than process piping and system.

• Location is critical for maintenance. Equipment that is hard to access is typically forgotten and not maintained.

> Process pumps/piping is a integral part of your evaporative cooling system. Failures to these components will shut your process down.

• To aid pump priming and avoid cavitation, locate pumps and pump suction piping at an elevation below the cooling tower cold water basin water level.

• Install strainers with properly sized baskets in pump suction piping.

• Install isolation valves to allow service of pumps and other equipment.

• Install piping and supports to ensure that there is no strain imposed upon the pump casing or other equipment.

• Use remote sumps or storage tanks to prevent system overflows. Vertical pipe runs above the cooling tower cold water basin level can cause the cooling tower basin to overflow at system shutdown. Remote sumps or storage tanks sized to hold the volume of liquid in the piping can be used to prevent the overflow and capture the liquid allowing it to be reused. This can save lots of money in water and chemical cost.

> Preventative maintenance is crucial to equipment performance and operational life.

• Establish a preventative maintenance program with scheduled maintenance intervals.

• Provide service platforms, ladders, cages and handrails as needed to allow easy and safe access to your equipment for maintenance.

• Rust is the enemy of galvanized evaporative cooling equipment. As part of your preventative maintenance program, clean and coat any rusted galvanized areas on your equipment with a high quality cold galvanizing compound.

> Water treatment is an important part of your preventative maintenance program. There are many water treatment systems on the market today including chemical less, dry chemicals and your traditional liquid chemicals. Consult with a water treatment specialist to determine which is best for your operation.

• Water samples should be taken monthly, and a written report should be kept.

• Save the reports for future reviews as this is important for troubleshooting treatment problems when they occur.

> Freeze protection is important even in the mild climate of the Carolinas. Protect your equipment that is located outdoors or in a non-conditioned space.

• Basin heaters are essential to prevent your cold water basins from freezing causing thousands of dollars in damage.

• Insulate and heat trace make up water and process piping.

• Make sure not to forget the process pumps and other ancillary equipment; you should insulate them or build insulated houses to protect them.

• Use antifreeze when possible.

• Maintaining flow through heat exchangers and coils can prevent freezing.

> During cold weather operation, ice can collect on components of your evaporative cooling equipment. Fan blades, fill media and inlet louvers are also susceptible to ice build-up.

• A vibration switch can detect ice formation on fan blades and shut the fan down before damage occurs.

• Install Variable Frequency Drives (VFDs) to vary the speed of your fan motors.

• Low water flow across the fill media can cause ice formation in the media which can cause structural damage to the equipment.

• Incorporate a Cold Weather Sequence of Operation into your control system which incorporates a defrost cycle.

Please feel free to contact us if you have any questions about the tips above or if you would like to schedule a FREE Mr. GoodTower equipment inspection.