Causes and treatment of cracks at the inlet of the cooler

Causes and treatment of cracks at the inlet of the cooler

The crack at the inlet and outlet of the cooler is a kind of brittle crack, which is generally manifested as a crack at the tip of the toothed plate, and then cracks along the intergranular. Cracking at the inlet and outlet of the cooler has a serious impact on work, not only reducing work efficiency, but also causing irreversible damage to the equipment. Today, we have organized some content to teach you how to prevent cracking at the inlet and outlet of the cooler.

First of all, we must first understand the reason for the cracking at the inlet and outlet of the cooler: the crack of the toothed plate weld at the inlet and outlet of the cooler is because the weld at the outlet end bears large welding residual stress and thermal stress, and is affected by high-quality chloride ions and high temperature in the medium Effect, chloride stress corrosion cracking occurred. When cracking occurs at the inlet and outlet of the cooler, the compression plate should be disconnected first, and then the upper expansion joint should be added to the insulating ladder, so that the expansion difference between the plate bundle and the compression plate can be absorbed. In order to greatly reduce the expansion constraint in the width direction of the plate, the tube plate structure is first cancelled, and the same dome cover is added on the upper part of the plate bundle as the lower part of the plate bundle.

　　 And how to prevent the problem of cracking at the inlet and outlet of the cooler? First of all, to improve the load-carrying capacity of the cooler, the comb-tooth plate can be updated to an insert structure. The length direction of 60mm is consistent with the force of the welded seam of the plate, and the end face only serves as a seal. The tube sheet is clamped by the equipment flange and can bear the quality of the sheet bundle. A supporting beam is arranged on the end face of the plate bundle. In order to improve the heat exchange effect, the length of the inlet and outlet channels of the plate bundle shell side at the crack is reduced. In order to facilitate the inspection of the upper expansion joint of the plate bundle, a hole can be provided in the upper shell of the cooler. If you want to remove the tube bundle, you can disconnect the lower end of the upper expansion joint first, and then disassemble the upper shell and the expansion joint.

　　 The above introduced the causes of cracks at the inlet and outlet of the cooler and the solutions, and focused on the prevention of cracking by improving the welding process and strictly controlling the temperature rise and fall speed. I hope you can apply it to actual operations to prevent problems before they occur.