About Recuperative Heat Exchangers:
The two types of heat exchangers most used are the Pre-heat systems, the Recuperative heat exchangers and Regenerative heat exchange type systems. Recuperative systems are also known as shell and tube type heat exchangers. In these heat exchangers, a stream of cold process gas passes through a series of tubes and is heated by another stream of gas which passes over the tubes on the shell side. These types of systems are generally used for thermal oxidizers with low to medium process flow rate, and generally can provide up to 80% thermal energy recovery effeciency.
USES:
Regenerative type heat exchangers use a media to absorb heat given off by one hotter fluid and transfer it to another colder fluid. Typical medias used are packed towers of ceramic material with required gaps for the gases to pass through them. The operation of regenerative heat exchangers is cyclic. In the first cycle hot gases/fluids passing through the media heat up the media. In the following cycle, the cold gases pass through the media and they are heated by the already hot media. Regenerative systems can operate with process flow rates in the low or high range, and can yield a thermal energy recovery efficiency between 80% and 95%+.
Heat Exchanger Effectiveness
These heat exchangers are used to transfer heat from hot gases at 1500°F to cold gases which are in the range of -10°F to 500°F. Effectiveness is a measure of the performance of a heat exchanger. Effectiveness is defined as the ratio of rate of heat transfer to the maximum possible heat transfer.