This invention relates to heat exchangers of the type in which fluid passing through one conduit heats or cools fluid surrounding the conduit.
In general, the effectiveness of a heat exchanger using two heat exchange fluids depends upon its ability to transfer heat between the fluids. In typical devices, the transfer is accomplished by passing the two fluids along opposite sides of a heat transfer member such as a metal plate or tube. Also vanes or fins have been employed which extend from one fluid-flow passage to the other to effect a heat transfer. It is, of course, desirable to obtain as much contact between the moving fluid and the heat transfer member or members. The patent to Wulf, U.S. Pat. No. 3,087,253 discloses vanes extending entirely across both a center flow passage and an enclosing annular passage. The heat exchanger of the patent to Powers, U.S. Pat. No. 2,291,985, discloses similar vanes extending part way across the flow passages. The patent to Strobel, U.S. Pat. No. 664,186, and that to Kasten, U.S. Pat. No. 3,200,948, disclose vanes in longitudinal chambers that do not extend to the ends of the chambers so that the fluid must reverse its flow direction as it moves along a heat transfer member. As pointed out above, each device features an arrangement which in one way or the other provides contact between the fluids and the heat transfer member of the device.
Other patents of interest are:
U.S. Pat. No. 3,446,278 PA1 U.S. Pat. No. 3,731,731 PA1 U.S. Pat. No. 3,453,840