Heat exchanger system for heating fluids - has fluid flowing over metal tube containing heating resistance wire

摘要

The electrically-heated heat exchanger has its heating resistance (1) located in a metal tube (2) free of air or filled with an inert gas. The metal tube is enclosed by a helix (3) made from tape and its pitch decreasing in passing from the inlet (4) to the outlet (5). The ends of the tube are sealed with insualting plugs (7). The fluid being heated flows in an outer tube enclosing the inner metal tube. The inlet pipe has a pressure-operated switch (6) to control the current supply to the heating resistance.