Investigations on a Porous Rotating Media Liquid-air Contacting Device Suitable for Various Alternative Cooling Technologies

Low energy and sustainable alternative air conditioning systems are getting more and more attention due to climate change concerns. High effectiveness, low cost and compact heat and mass exchangers play an important role in making such technology competitive with conventional technologies. This communication describes a novel counter-flow liquid-gas contacting device, which uses highly porous and rotating cylindrical contact media made from wire screens. The device can have very high surface area density, exceeding 500 m2/m3. The device can be used as a modular evaporative cooler, indirect evaporative cooler as well as liquid desiccant based air dehumidification system. Low pressure drops across device, low electrical power consumption, ability to run on solar PV cells, least chances of liquid carryover and prospective high effectiveness are the important features of this device. The small modular device with 110 mm diameter and half a meter length could provide cooling at a rate exceeding 200 W in evaporative cooling experiment with consumption of 10 W power. The effectiveness exceeding 50% could be achieved under moderately hot and dry conditions. Better performance is expected for dry and hot summer conditions. Preliminary trials for combined direct and indirect evaporative cooling and liquid desiccant dehumidifier are also taken and encouraging results are achieved.