CORROSION-RESISTANT BIMETALLIC TUBE AND ITS USE IN TUBE BUNDLE EQUIPMENT

摘要

A bimetallic tube consisting of at least one tubular element in a first metal resistant to the corrosive and/or erosive action of a process fluid with which it is put in contact, having at least one end, or an area close to an end, externally coated with a layer of a second metal, different from the first and more suitable, with respect to this, for being seal-welded to a support. Tube bundle equipment to be used for thermal exchange operations at high temperatures and pressures, under conditions of high aggressiveness of the process fluids, wherein the tube bundle comprises at least one tube having the above characteristics.;Said equipment is particularly used as a heat exchanger and decomposer, for example as a stripper, in the cycle of urea synthesis processes where there are conditions of high pressure, high temperatures, high aggressiveness of the process fluids, and in which the tube bundle consists of at least one tube having the above characteristics.

主权项

1: A bimetallic tube resistant to the corrosive action of a process fluid with which it is put in contact on its internal surface, comprising a first tubular element E1 (1) facing said internal surface, consisting of a metal M1 selected from Zr, Ta, Nb and Al or an alloy of said metals, homogeneously extending for the whole length of the tube, and at least a second tubular element E2 (2), consisting of a second metal or alloy M2 different from M1, arranged circularly outside said first tubular element, in a position close to one of its ends, for a section of less than a third of the length of the tube itself, and seal attached to said element E1.