High efficiency wet surface air coolers
Alfa Laval WSACs incorporate a number of unique technologies that ensure low operating costs and high performance.
Maximum cooling efficiency and lowest possible outlet temperature
WetSurface technology offers several distinct benefits:
- A WSAC cooling system is compact and has low power consumption thanks to its high cooling efficiency.
- The process medium output temperature is as low as possible thanks to the single approach to the wet bulb temperature.
Wet surface air coolers vs traditional air-cooled heat exchangers
Unlike traditional air-cooled heat exchangers, the tube bundles in a WSAC are sprayed with water and use evaporative cooling to reject the heat from the process medium. This results in superior cooling and a WSAC is both significantly smaller, has a lower power consumption and lower output temperature than an air cooler.
Since the tube bundles are sprayed directly with cooling water, a WSAC system has a single approach to the wet bulb temperature, meaning the process medium output temperature is as low as possible. A WSAC system is capable of cooling the process medium to a temperature just 2.7°C (5°F) above the surrounding wet bulb temperature.
Wet surface air coolers vs cooling towers
A cooling tower/heat exchanger system, on the other hand, has two approaches to the wet bulb temperature due to the intermediate cooling water loop. This means the process medium output temperature will always be higher and an extra chiller stage is required to achieve the same results as with a WSAC.
The cooling water spray and air travel in the same direction (co-current draft), which creates a uniform water film on the tubes that minimizes corrosion.
A WSAC can operate on recycled water of low quality such as blowdown water
Thanks to the spacing between the tubes, the nozzle design and the absence of cooling tower fill, a WSAC can operate on water of low quality, e.g. blowdown water from a cooling tower, treated wastewater or sea water.
A WSAC can run on significantly higher cycles of concentration (C.O.C.) than a cooling tower. A common C.O.C. for a WSAC is around 6 whereas a cooling tower can only go as high as 3 before clogging in the heat exchanger starts to become a concern.
The flexibility in water sources and the high C.O.C reduces water consumption and associated costs significantly, making WSAC an ideal choice for regions where water is expensive.