Method for maintaining furnace lining composite fireproof material of submerged arc furnace

Abstract

The invention discloses a method for maintaining a furnace lining composite fireproof material of a submerged arc furnace. The method includes the following steps: sealing and pressing a furnace: closing connection channel openings between a furnace top riser pipe of a coke furnace at a maintenance side and axle tubes and/or near-end gate plates of a gas collection pipe at the maintenance side; forming holes in a pipe wall: at least forming a construction hole and a convection hole in the gas collection pipe at the maintenance side; dissipating heat and exchanging air: dissipating and discharging high temperature gas in the gas collection pipe; sealing a gate: sealing side surfaces of the near-end gate plates of the gas collection pipe; detaching a thermal insulation layer; sealing axle tube openings; building a thermal insulation layer; performing once hole sealing; demounting a seal; demounting seals of the side surfaces of the near-end gate plates of the gas collection pipe and a seal of a connection channel opening between each axle tube and the gas collection pipe; performing twice hole sealing; opening all the gate plates; opening the gate plates of the riser pipe in order; repairing a steel housing; and cleaning a site. The maintaining method can achieve maintain the submerged arc furnace in a constant heat production, is low in maintenance cost, and is short in construction period.

Description

technical field [0001] The invention belongs to the technical field of submerged arc furnace lining maintenance, and in particular relates to a hot-state maintenance method for the inner lining heat insulation layer of a submerged arc furnace. Background technique [0002] Submerged Arc Furnace is a high energy consumption industrial electric furnace with wide application, various styles and continuous operation. During the production of submerged arc furnace, a large amount of high-temperature polluted flue gas will be produced. The heat energy taken away by the flue gas is equivalent to 40%-50% of the total heat energy input into the submerged arc furnace. The temperature of the waste heat of the flue gas is relatively high, which belongs to high-grade waste heat. Direct discharge of high-temperature flue gas will not only cause environmental pollution, but also waste a lot of heat energy resources. [0003] The structure of the existing submerged arc furnace heat collect...

AI Technical Summary

Problems solved by technology

After the heat insulation layer of the air collecting pipe lining is damaged or collapsed, not only the thermal damage is serious, the waste heat cannot be fully and effectively utilized, but also the steel shell of the air collecting pipe loses the protection of the heat insulating layer, which intensifies the oxidation of the steel shell, and even leads to melting and burning. pose a major safety hazard

[0004] At present, the method of repairing the burnt gas collecting pipe is to adopt the method of shutting down the coke oven to repair or replace it. This cold maintenance method has many shortcomings: firstly, the coke oven body, especially the inner lining of the carbonization chamber, is made of silica bricks. After the silica bricks stop the furnace for cooling and come into contact with cold air, they are prone to a large number of shrinkage cracks, and even fall off and collapse. In severe cases, the entire furnace body will be scrapped.

In addition, the heat recovery boiler is connected to numerous carbonization chambers and furnace bodies through the gas collection main pipe and several gas collection branch pipes. After some carbonization chambers are shut down, the waste heat input to the heat recovery boiler must be reduced, resulting in uneven and fluctuating supply of boiler waste heat. This in turn directly affects the optimal operation and normal operating efficiency of downstream driven turbines and drives

In addition, in the existing maintenance method, a new air-collecting pipe steel shell is remade on the ground, and an inner liner heat insulation layer is built in it, and then the old pipe is replaced with a new air-collecting pipe. The original air-collecting pipe steel shell material and The sound insulation materials in the air collecting pipe are all discarded, resulting in waste. What is more serious is that the huge and heavy air collecting pipe has a large amount of lifting and replacement engineering, and the maintenance cost is also very high. Hot bricks are easy to cause loosening and dislocation, which affects the integrity of the lining structure. The light ones affect the thermal insulation effect of the new gas collection pipe, and the severe ones need to be repaired and arranged again.