Furnace roller surface anti-dross device of strip steel annealing furnace

Abstract

The invention discloses a furnace roller surface anti-dross device of a strip steel annealing furnace, belongs to the equipment of strip steel thermal treatment, and in particular relates to a continuous strip steel annealing furnace. The furnace roller surface anti-dross device is characterized in that a gas inlet pipeline is arranged on a nitrogen conveying tube; the gas outlet end of the gas inlet pipeline is connected with a nitrogen humidifying device through a nitrogen inlet valve, a depressurizing valve, a wet gas adjusting valve and a dry gas adjusting valve; the nitrogen humidifying device is connected with a wet gas nozzle at the bottom of a uniform heating section of the annealing furnace through a wet gas inlet adjusting valve and an injection pipeline; and a gas path is formed by the gas inlet pipeline, the nitrogen humidifying device, the injection pipeline and the annealing furnace. The furnace roller surface anti-dross device has the advantages that the dew point of the atmosphere of the uniform heating section inside the annealing furnace is minus 27 DEG C to minus 35 DEG C, gas particles with high dew points are firstly enriched at rough valley points of a non-strip steel contact surface of a furnace roller, the high temperature strip steel from the heating section wraps the gas particles, and the gas particles are heated to expand, so that the sponge iron on the strip steel is effectively prevented from being bonded into dross on the furnace roller, the product quality is improved, the times of opening the furnace to replace the roller are reduced, the cost of spare parts and the production cost are lowered, and the product yield and the machine set working rate are increased.

Description

technical field [0001] The invention belongs to strip steel heat treatment equipment, in particular to a strip steel continuous annealing furnace. Background technique [0002] The continuous annealing furnace is an important cold rolling annealing equipment. The currently used annealing furnace is equipped with a preheating section, a heating section, a soaking section, a slow cooling section, a fast cooling section, an overaging section, a secondary cooling section and a final cooling section. The soaking section of the closed furnace chamber is filled with nitrogen-hydrogen mixed gas with a dew point of -40°C to -50°C. The strip steel at normal temperature enters the furnace and is preheated and heated continuously in the heating section. The surface temperature of the strip steel in the soaking section reaches as high as 680°C to 850°C, and lasts for 44s to 109s in the soaking section. Because a small amount of iron oxide on the surface of the strip is reduced to sponge...

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Problems solved by technology

Because a small amount of iron oxide on the surface of the strip is reduced to sponge iron under the conditions of high temperature and reducing atmosphere, coupled with the speed difference between the strip and the furnace roll (the change of the speed of the unit and the speed difference of the inertial system of the steel belt) and the surface of the furnace roll Due to the roughness of the roller surface, the generated sponge iron is very easy to take root and grow at the valley point of the roller surface roughness. , affecting the quality of strip products

At present, the anti-nodulation device on the furnace roll surface of the strip steel annealing furnace has not been disclosed to solve the problem of nodulation on the furnace roll surface. Only the anti-nodulation DPC-74 (cermet) is used as the coating material for the furnace roll. The disadvantage is that the price of the coating material is high. Increase the production cost; or increase the number of times of furnace opening and replace the nodulation furnace roll. The disadvantage is that once the furnace is opened, the temperature will be lowered and then heated up, and the energy consumption will be large. Frequent furnace opening will affect the service life of the annealing furnace. Consumption of spare parts greatly increases production costs

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