Bulk heat treatment system for online replacement of dome of large-scale hot-blast stove

Abstract

The invention relates to a bulk heat treatment system for online replacement of a dome of a large-scale hot-blast stove. According to the bulk heat treatment system, a heating part comprises electric heaters; a mounting bracket is served as a cage-type frame positioned in the inner cavity of a hot-blast stove dome; a plurality of the electric heaters are mounted on the cage-type frame in a trapezoidal and layered manner, and divided into groups; a power line is led out from each group of the electric heaters and connected to the heating output end of an intelligent temperature controller; a temperature measuring and controlling part comprises a thermocouple and the intelligent temperature controller; a plurality of the electric heaters are arranged outside the hot-blast stove dome in a layer manner; a feedback line of the thermocouple is connected with the intelligent temperature controller; a temperature sensing element is in spot welding connection with the surface of the hot-blast stove dome; a power supply of the intelligent temperature controller is served as a mobile diesel generator car; a heat preservation layer I is laid on the outer wall of the hot-blast stove dome; a steel structure platform is arranged at the lower port of the hot-blast stove dome through a supporting wall pier; and a heat preservation layer II is laid on the steel structure platform. The bulk heat treatment system provided by the invention adopts an integral electric heating and heat treatment process, so that the welding stress can be eliminated, a weld can be protected from hydrogen embrittlement and cracking; and the purposes of reducing the hardness, improving the plasticity and improving the toughness can be fulfilled.

Description

technical field [0001] The invention relates to a heat treatment system, in particular to an integral heat treatment system for online replacement of a large-scale hot blast stove vault. Background technique [0002] At present, large (4000 cubic meters) blast furnace internal combustion hot blast stoves are in use due to the high temperature of the vault and the poor use conditions. In the case of intergranular stress corrosion, cracks will appear in many places on the base metal. The vault needs to be replaced in its entirety. However, the total weight of the hot blast stove vault is about 111 tons, the maximum diameter is 12200mm, the elevation of the furnace roof is 47470mm, and the elevation of the replacement part is 37334mm, that is, the 10m vault is replaced at the elevation of 37m. In addition to ensuring the welding quality, overall heat treatment must be carried out to eliminate welding stress and avoid intergranular stress corrosion (occurring under the combined...

AI Technical Summary

Problems solved by technology

In addition, there will be other hot blast stoves in normal use on site, which is a gas hazard area, no open flames are allowed, conventional fuel oil heat treatment schemes are excluded, and local heat treatment of weld seams. Since the hot blast stove is a welded rigid body, local annealing to eliminate stress will have a greater impact on the shell The temperature gradient stress will affect the accuracy and safe use of the shell, so it is not allowed to use

If the overall internal electrolytic heat treatment is adopted, since the effective space of the hot blast stove is about 820 cubic meters and the weight is 111 tons, it will require 2100 kilowatts of heat in terms of thermal power, so the site cannot solve such a large amount of electricity

Images