A connection structure of heat exchange tube and tube sheet to prevent gap corrosion on shell side

Abstract

The invention discloses a connection structure between a heat exchange tube and a tube sheet for preventing gap corrosion on the shell side, including a tube sheet and a heat exchange tube, wherein the tube sheet includes a tube sheet body and a surfacing layer, and the tube sheet includes a tube sheet body and a surfacing layer. One side of the plate body is the tube side, the other side of the tube plate body is the shell side, the shell side of the tube plate body is provided with a surfacing layer, and the surfacing layer and the tube plate body The surfacing welding between them forms a fusion surface; the tube sheet is provided with a tube hole, and the heat exchange tube is inserted into the tube hole and connected with the tube sheet by expansion joint and / or welding. The present invention selects a reasonable structure on the shell side of the tube sheet to prevent the corrosive medium from penetrating into the gap between the tube sheet and the heat exchange tube, thereby achieving the purpose of preventing crevice corrosion. Compared with the prior art, the invention can better improve the corrosion resistance of the tube bundles of the tube-and-tube heat exchanger, prolong the service life of the equipment, and also have the characteristics of simple structure, low cost and easy manufacture.

Description

technical field [0001] The invention relates to the field of heat exchange equipment in the industries of air conditioning, coal chemical industry and petrochemical industry, in particular to a connection structure between a heat exchange tube and a tube sheet for preventing shell-side gap corrosion. Background technique [0002] The so-called crevice corrosion is that those fluids are easy to corrode in dead corners that do not flow. Crevice corrosion is a form of localized corrosion, which may occur in the gap where the solution is stagnant or in the shielded surface. Such gaps may form at metal-to-metal or metal-to-nonmetal junctions. In the manufacture of chemical equipment, the existence of gaps or dead angles as mentioned above should be avoided as much as possible, or measures should be taken to block gaps and dead angles to avoid crevice corrosion. [0003] In chemical heat exchangers, corrosive environments are often encountered, especially highly corrosive media, ...

AI Technical Summary

Problems solved by technology

Due to structural reasons, the tube side of the heat exchanger is easy to be sealed by expansion and welding, while the shell side is more difficult to achieve sealing, usually by expansion, but the common expansion method is between the heat exchange tube and the tube sheet. There is still a gap between them, and the shell-side medium can immerse into the gap, accumulate and corrode the inner wall of the tube hole of the tube sheet, and easily cause the tube head to fall off, which is especially obvious in large-scale surfacing tube sheets

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