Abstract: With a view to improving the heat transfer in exothermic reactions and simplifying the construction of the cooling system of the reactor, in particular a stirrer reactor, vertical boiling tubes which are sealed at the bottom are provided, above which is arranged a condensate collecting and liquid distributing chamber in which a sufficient layer of cooling liquid is constantly maintained by means of a liquid level regulator. Cooling fluid and the vapor produced flow in direct contact with each other as they are carried in counter current through the boiling tubes which have only single walls. The vapor passes through the layer of cooling fluid and is continuously discharged and preferably recovered. The condensate is preferably returned to the cooling system.

Abstract: Each sheath tube of a bayonet type heat exchanger is provided with spacer means secured thereto and extending inwardly from the inner wall surface thereof to define an opening through which the respective bayonet tube freely extends at least generally coaxially with the sheath tube, the surface of the spacer means adjacent the bayonet tube being smoothly contoured to substantially minimize damage to the bayonet tube from vibration.