Abstract: Heat exchanger for heat-transfer between substances of high pressure difference including a shell, a region through which a cooler substance is conveyed; an inlet for the cooler substance; a bundle of tubes arranged in a cooler substance compartment; and riser conduits operatively connectible to the shell and communicating with the compartment, with the substance to be cooled being passed through the tubes having a high temperature at the inlet of the heat exchanger and at the outlet; a tube bottom of predetermined thickness arranged at the heat exchanger inlet; and a device including a support-grating arranged in the vicinity of the tube bottom, operatively connectible to the shell and extending at least nearly perpendicular to the tube bottom in the region through which the cooler substance is conveyed.

Abstract: A pipe assembly-heat exchanger-steam drum unit, which comprises a pipe assembly heat exchanger for a heat exchange between media of relatively high pressure differentials and a steam drum with a liquid chamber and a steam chamber while the medium passing through the pipes of the pipe assembly-heat exchanger has a high entering temperature, and a pipe bottom located on the inflow side of the hot medium is thin. In the pipe assembly heat exchanger there is furthermore provided a device for relieving the thin pipe bottom. In the pipe assembly-heat exchanger there is also provided a device which is so designed that the cold medium entering the pipe assembly-heat exchanger is conveyed to the thin pipe bottom. The pipes of the pipe assembly-heat exchanger are as an assembly of pipes transversely and centrally passed through the steam drum while the pipe assembly-heat exchanger and the steam drum form a unit with each other.