Abstract: The operating efficiency of indirect evaporative cooling processes and indirect evaporative cooling apparatus employing a dry side channel and a wet side channel separated by a heat exchange plate are improved by placement of holes in the heat exchange plate. Further improvements are obtained when the flow direction in the wet side channel is cross-current to the flow direction in the dry side channel. Placement of desiccant materials in the dry side channel also serve to improve the operating efficiencies of these processes and apparatus.

Abstract: The within invention improves on the indirect evaporative cooling method and apparatus by making use of a working fluid that is pre-cooled with and without desiccants before it is passed through a Wet Channel where evaporative fluid is on the walls to take heat and store it in the working fluid as increased latent heat. The heat transfer across the membrane between the Dry Channel and the Wet Channel may have dry, solid desiccant or liquid desiccant and may have perforations, pores or capillary pathways. The evaporative fluid may be water, fuel, or any substance that has the capacity to take heat as latent heat. The Wet Channel or excess cooled fluid is in heat transfer contact with a Product Channel where Product Fluid is cooled without adding any humidity. An alternative embodiment for heat transfer between adjacent channels is with heat pipes.

Abstract: The within invention improves on the indirect evaporative cooling method and apparatus by making use of a working fluid that is pre-cooled with and without desiccants before it is passed through a Wet Channel where evaporative fluid is on the walls to take heat and store it in the working fluid as increased latent heat. The heat transfer across the membrane between the Dry Channel and the Wet Channel may have dry, solid desiccant or liquid desiccant and may have perforations, pores or capillary pathways. The evaporative fluid may be water, fuel, or any substance that has the capacity to take heat as latent heat. The Wet Channel or excess cooled fluid is in heat transfer contact with a Product Channel where Product Fluid is cooled without adding any humidity. An alternative embodiment for heat transfer between adjacent channels is with heat pipes.

Abstract: An improved method and apparatus for indirect evaporative cooling of a fluid stream to substantially its dew point temperature. Plate heat exchanger has perforations 11 and channels 3, 4 and 5 for gas or a low temperature for liquids on a dry side and wet side. Fluid streams 1 flow across the dry side 9, transferring heat to the plate. Gas stream 2 flows across the dry side and through perforations to channels 5 on wet side 10, which it then cools by evaporative cooling as well as conductive and radiative transfer of heat from plate. A wicking material provides wetting of wet side. In other embodiments, a desiccant wheel may be used to dehumidify the gas, air streams may be recirculated, feeder wicks 13 and a pump may be used to bring water from a water reservoir, and fans may be used to either force or induce a draft. The wicking material may be cellulose, organic fibers, organic based fibers, polyester, polypropylene, carbon-based fibers, silicon based fibers, fiberglass, or combinations of them.

Abstract: The within invention improves on the indirect evaporative cooling method and apparatus by making use of a working fluid that is pre- cooled with and without desiccants before it is passed through a Wet Channel where evaporative fluid is on the walls to take heat and store it in the working fluid as increased latent heat. The heat transfer across the membrane between the Dry Channel and the Wet Channel may have dry, solid desiccant or liquid desiccant and may have perforations, pores or capillary pathways. The evaporative fluid may be water, fuel, or any substance that has the capacity to take heat as latent heat. The Wet Channel or excess cooled fluid is in heat transfer contact with a Product Channel where Product Fluid is cooled without adding any humidity. An alternative embodiment for heat transfer between adjacent channels is with heat pipes.