Abstract: The heat exchanger according to the invention consists of two flat or slightly incurved parallel surfaces formed in two sheets of metal (2) and (3). The longitudinal edge pieces (8) and (9) and transverse edge pieces (12) and (13) have rounded edges. The entire exterior surface is coated with enamel. These exchangers may be used in groups of several parallel units arranged inside a tubular body, or they may be disposed in a radiating pattern inside a cylindrical tank in a chemical reactor, forming a complex exchanger. This invention is of interest to manufacturers of industrial heat exchangers, particularly exchangers designed for the chemcial, pharmaceutical or agricultural/food industries.

Abstract: A thermal sensor, in particular for a chemical reactor comprises an enamelled cylindrical shell having at its inner end a thin base and an inner sleeve welded to the base of the shell. A temperature measuring head comprising at least one thermal sensing element in a compression resistant insulating mass of low thermal inertia in a casing is pressed against the base of the shell by a compression spring acting between the temperature measuring head and a connector coupled to the inner sleeve of the shell by a bayonet point. Lead wires from the temperature measuring head extend out through a tubular stem having at its inner end a socket connected with the connector by a second bayonet joint. A guide sleeve has an inner end surrounding the inner sleeve of the shell and a reduced diameter outer end receiving the tubular stem. The bayonet joints provide for easy removal and replacement of the temperature measuring head.