Repair method and device of welding defect of inner hole welding in U-shaped pipe type heat exchanger

Abstract

The invention relates to a repair method and device of a welding defect of inner hole welding in a U-shaped pipe type heat exchanger. The repair method uses a designed repair device to completely remove an inner hole welding line generating the defects, and form a new inner hole welding groove in a pipe plate, an original U-shaped heat exchange pipe is drawn out and replaced with a new U-shaped heat exchange pipe is replaced, and inner hole welding is carried out on the new U-shaped heat exchange pipe and a pipe plate set again, the repair device comprises a height fixing nut, a cushion block,a positioning ring, a push rod, a shaft sleeve, a pin shaft and a cutting blade, according to the repair method and device of the welding defect of inner hole welding in the U-shaped pipe type heat exchanger, the phenomenon that after a defect appears in an inner hole welding line at present, a manner of blocking a pipe hole of a pipe plate is only adopted for repair can be avoided thoroughly, the inner hole welding line maintainability is greatly improved, and the large-scale application of the inner hole welding technology can be greatly promoted.

Description

technical field [0001] The invention belongs to the field of welding technology, and in particular relates to a method and a device for repairing welding defects of inner hole welding in a U-shaped tube heat exchanger. Background technique [0002] U-shaped tube heat exchanger is a kind of tube-and-tube heat exchanger. It has many advantages such as simple and compact structure, good thermal compensation, and easy cleaning. It is widely used in petroleum, chemical, energy and other industries. As the name implies, the heat exchange tube of the U-shaped tube heat exchanger is U-shaped, and it is generally connected to the tube sheet by welding to form a tube bundle. The weld quality of the heat exchange tube and the tube sheet directly affects the heat exchange performance and working stability of the U-shaped tube heat exchanger. The traditional welded joints of heat exchange tubes and tube sheets are located at the end of the tube sheet, which is a typical fillet joint, s...

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Problems solved by technology

[0004] Inner hole welding requires high technology and difficult operation. Small changes in welding parameters and welding environment will lead to welding defects, and U-shaped tube heat exchangers in important occasions usually require compact structure, so the arrangement of heat exchange tubes is relatively dense. , the operating space is small, once any welding defect occurs, it can only be remedied by plugging the tube holes of the tube sheet, and when there are many tube holes with welding defects, the entire heat exchanger will be scrapped

At present, the difficult maintenance of the inner hole welding seam has become an important factor restricting its large-scale application. However, in addition to the above-mentioned method of sealing the tube hole of the tube sheet, there are no other methods for the repair of inner hole welding defects. in newspaper

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