Abstract: A shell and tube heat exchanger comprising: a shell having an inlet end-cap attached to a first end of the shell, wherein an outlet end-cap is attached to a second end of the shell and a tube bundle being housed within the shell, said tube bundle including a plurality of parallel-spaced tubes that traverse the interior of shell from a first end to a second end of the tube bundle, and wherein a plurality of baffles are arranged within the shell supporting the parallel-spaced tubes of the tube bundle. At least a part of the shell and tube heat exchanger is provided with a coating comprising silicon oxide, SiOx.

Abstract: The invention relates to a spiral heat exchanger comprising a spiral body formed by at least one spiral sheet wound to form the spiral body forming at least a first spiral-shaped flow channel for a first medium and a second spiral-shaped flow channel for a second medium, wherein the spiral body is enclosed by a substantially cylindrical shell being provided with connecting elements communicating with the first flow channel and the second flow channel. At least a part of the spiral heat exchanger is provided with a coating comprising silicon oxide, SiOx.