A method for replacing the elbow of a gasification furnace chilling pipe

Abstract

The invention provides a gasifier chilling pipe elbow replacing method. The method includes the following steps of firstly, determining a forge piece; secondly, determining segmentation; thirdly, conducting sectioning; fourthly, conducting replacement welding; fifthly, sectioning symmetrical segments; sixthly, conducting replacement welding on the symmetrical segments; seventhly, detecting the quality. The restorative overhaul is conducted according to the original design of the device, the channel gas field distribution of the original design is not changed, the stress distribution is uniform, the service life is long, the expense is low, the price of the whole force piece is less than 0.1 million, and the total tailor-welding price of a single elbow exceeds 0.25 million, replacement is rapid, replacement time is short, and there is no need to recalculate whether the stress distribution is reasonable or not; in the prior art, a qualified design organization needs to be found to simulate and calculate whether the stress distribution is reasonable or not through the single-elbow welding method, and the design expense is greatly increased.

Description

technical field [0001] The invention relates to a method for replacing the elbow of a chilling pipe of a gasification furnace, and belongs to the technical field of improving pulverized coal pressurized gasification devices. Background technique [0002] The coal gasification process of gas quenching is adopted, and the inner chamber of the gasifier is divided into upper and lower parts. The lower part is the combustion chamber, and the upper part is the quenching chamber. Coal powder and oxygen react in the combustion chamber, and the temperature is about 1600 ℃. In order to avoid high temperature, slag corrosion, and damage to the refractory material caused by the stress caused by the start and stop of the lower combustion chamber, the gasifier cannot operate for a long period of time. Material coating, relying on the slag layer hanging on the water-cooled wall to protect the metal water-cooled wall during normal operation; high-temperature syngas flows from the top of the...

AI Technical Summary

Problems solved by technology

[0007] (3) The thickness of the elbow exceeds 50mm, and the distance between the adjacent elbow channels is only 50mm. It is difficult to weld after cutting from the middle of the adjacent elbow channels according to conventional methods, time-consuming and difficult to penetrate, and the residual stress is large. After welding, heat treatment is required. Due to the limitation of structure and space, it is difficult to meet the heat treatment process of the material after heat treatment heating, constant temperature and cooling of the forged elbow after welding, resulting in stress concentration and affecting the welding quality;

[0008] (4) Limited by space, the weld cannot be inspected for flaw detection. If the overall elbow interface is not penetrated, it is prone to breakage during operation

[0009] At present, for the replacement of the elbow, since the gasifier device is installed and sealed, it is impossible to put the whole elbow directly into the image 3 The overall replacement installation is performed at the position A shown, so Shell gasifier installations around the world use a single elbow tailor welding to replace the overall elbow, which leads to uneven stress distribution and easy deformation

First use the "Ω" tube to manufacture a single elbow according to the design bending radius, and weld a reinforcing plate on the elbow according to the stress calculation, and then a certain number of tailor-welded a group of elbows for replacement, time-consuming and long construction period, complex construction

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