As discussed in the Liquid Desiccant Tutorial, our scavenging-air regenerator uses low-flow liquid-desiccant technology to achieve very high COPs and eliminate carryover of desiccant droplets.  The core of this regenerator is a liquid-to-gas heat exchanger.  The plates of this heat exchanger are made from a high-temperature plastic extrusion that is 4.5" wide, 0.12" thick, and has internal cooling passages running its length.

The regenerator is most efficient when it is used with an air-to-air heat exchanger that preheats the incoming air using the humid exhaust air.   The following two graphs show the performance of a 2 X 75 plate, scavenging-air regenerator that concentrates lithium chloride from 39% to 43%.  The performance of the regenerator is shown as a function of the hot water inlet temperature both with and without an 80% effective Interchange Heat Exchanger.

The graph of COP shows the important role that the Interchange Heat Exchanger plays in improving the efficiency of the regenerator.  Omitting this critical component can reduce the regeneration COP by as much as 25%.

When operating on hot water provided by a gas-fired water heater, the efficiency of the water heater must be included in the calculation of a regeneration COP based on gas use.  If the water heater has a 82% efficiency, the gas-based COP for the regenerator operating with  200 F hot water will be 0.61.  This gas-based COP can be increased to slightly over one by using a  1½-effect regenerator with two stages of regeneration..