Method for repairing water-cooled wall of circulating fluidized bed by adopting laser cladding

Abstract

A method for repairing a water-cooled wall of a circulating fluidized bed by adopting laser cladding is characterized in that during laser cladding, firstly using a frock to clamp a pipe where an circular arc shaped surface of the water-cooled wall is located to ensure the flatness of the pipe, rotating the frock to clad the next piece of circular arc shaped surface after cladding one piece of circular arc shaped surface, completing cladding the whole circular arc shaped surface through reciprocating motion of a bare head and continuous rotation of the pipe and then using the same method to clad the next circular arc shaped surface of the water-cooled wall; during cladding, the laser beams moving back and forth at the top of the circular arc shaped surface along the longitudinal directionof the water-cooled wall to carry out scanning radiation of the spots with diameter of 4mm, wherein the power of the laser beams is 6000-10000W and the thickness of the laser cladding layer is 0.5-0.7mm; pumping high pressure air to the interior of the water-cooled water pipe where the cladding region is located; and directly feeding the powder to the molten pool by virtue of the kinetic energy of the powder by way of feeding powder under gravity. The method has the characteristics of strong adaptability, simple and convenient operation, low thermal deformation and metallurgical bonding between the coating and the base material.

Description

technical field [0001] The invention relates to a method for repairing failed parts of boiler equipment, in particular to a method for repairing a circulating fluidized bed water wall by laser cladding, which belongs to the technical field of C23C24 / 10 (2006.01) I in the IPC International Patent Classification Table. Background technique [0002] The water wall of the circulating fluidized bed used in petrochemical industry is located around the lower part of the combustion chamber; due to the long-term work at high temperature and the wear of the outer wall of the pipeline by the fuel and fly ash under the action of the primary and secondary air, and the corrosion of sulfur, It often causes the water wall to leak during the working process, forcing the boiler to stop production, causing losses to the user's economy and affecting the production plan. [0003] In order to prolong the service life of the water-cooled wall, spraying is often used on the wall of the water-cooled...

AI Technical Summary

Problems solved by technology

But for other specific equipment components, especially in special structures like water-cooled walls (that is, many finned tubes are welded together longitudinally and sequentially to form a whole piece of water-cooled wall with a heating surface area of ​​about 10m×2m, and the entire surface It is a wavy surface composed of semi-circular arcs. During cladding, it is necessary to ensure that the light spot is irradiated vertically on the cladding surface (that is, the cladding work area is always on the top of the water-cooled wall tube). The existing laser cladding process can no longer adapt to the application of this project.

[0012] After searching and checking by the applicant: there is no precedent in China, and no related reports have been seen abroad. It is still necessary for technical personnel in the field to make further efforts to find out the appropriate method of using laser cladding to repair the water wall of the circulating fluidized bed used in petrochemical industry. creative research work