IMPROVEMENTS IN CONTROL OF HEAT EXCHANGERS

摘要

A heat exchanger (10) has an outer housing (16) and a first helical fluid fl ow path or coil (12) located in the housing (16) defining a plurality of turns and having an inlet (24) and an outlet (22) for entry and exit of fluid into the flow path to be heated or cooled. A second helical coil (14) defining a second fluid flow path is located within the housing (16) adjacent to the first coil. The second coil also has an inlet (24) and outlet (22) for a passage for hot or cold service media. A conductive or non-conductive sheath (18) is disposed between the coils. A transfer medium is disposed in the housing for transfer of heat between the first and second flow paths. A plurality of baffles (20) are located between the outer housing and sheath a nd disposed between turns of the first coil. A plurality of baffles (21) are al so disposed between turns of the second coil (14). By interposing a transfer medium between the two fluid flow paths rather than having one of the fluid flows as the medium itself, control over the cooling or heating of the fluid to be heated or cooled is possible. The fluid being cooled or heated and flu id transfer medium may be at different temperatures. The sheath (18) and baffle s (20, 21) help control the transfer of heat and improve the efficiency of the heat exchanger.