High temperature annealing air distribution system in orientation silicon steel strip coil bell type furnace

Abstract

The invention provides a high temperature annealing air distribution system in an orientation silicon steel strip coil bell type furnace, which comprises an air supply pipeline, a water vapor channel and an air return pipeline. The air supply pipeline extends into the inside of the bell type furnace from a centre position of the bottom of the bell type furnace and is lifted to the top of the highest steel strip coil in the bell type furnace, and air outlet through holes are evenly drilled on the pipe wall in the radial direction and the axial direction. Water vapor through holes are arranged on a horizontal bearing support plate body used for bearing each layer of steel strip coils in the bell type furnace, and the air return pipeline is an annular pipeline arranged at the bottom in the furnace close to the inner wall of an outer cover. The air distribution system enables atmosphere in the furnace to be even, and maintains balance of air inlet and air outlet for a long time. When the cover is uncovered, hydrogen in the furnace is exhausted, and the air distribution system eliminates potential safety hazard, prevents steel strip surface to be oxidized, guarantees safety in the furnace, and is high in product quality.

Description

technical field [0001] The invention relates to a gas distribution process for high-temperature annealing of an oriented silicon steel coil in a bell furnace, specifically applied to high-temperature heat treatment of an oriented silicon steel coil in a bell furnace, and belongs to the technical field of functional magnetic materials. Background technique [0002] Oriented silicon steel strip is a new type of functional magnetic material. Because of its high resistance, the electric energy consumed on the iron core is small during operation; because its magnetization has strong directionality, the magnetic field in the desired direction High sensitivity, high utilization rate of iron core, high operating efficiency, cold-rolled oriented silicon steel strip is the most critical and important iron core material in electromagnetic directional conversion products such as transformers and transformers, the production technology level of cold-rolled oriented silicon steel strip, di...

AI Technical Summary

Problems solved by technology

[0026] 1. Uneven gas distribution in the furnace

[0027] Because the gas is fed into the furnace from the center of the furnace bottom, and returns to the outside of the furnace from the outer edge of the bottom of the furnace, and the atmosphere in the furnace has back pressure, it cannot be guaranteed that the gas supplied will reach the top of the furnace. The temperature in the furnace is very high, reaching 1180°C-1200°C at the highest temperature. At such a high temperature, it is impossible to install machinery in the furnace to make the atmosphere in the furnace perform forced mechanical circulation. Therefore, the atmosphere fed into the furnace will be Directly take a short circuit at the lower part of the furnace and enter the air return hole to discharge out of the furnace

[0028] Due to the uneven atmosphere, the temperature in the furnace is also uneven, which makes the product quality in the furnace inconsistent

[0029] 2. There are security risks

However, under the same conditions, the specific gravity of nitrogen is heavier than that of hydrogen. According to the gas supply and return process of the above-mentioned bell-type furnace, because nitrogen cannot be supplied to the furnace top, the high-temperature annealing of the steel strip coils loaded into the bell-type furnace for high-temperature annealing ends. Finally, when the bell furnace is uncovered, hydrogen is still accumulated on the top of the bell, but at this time, there is oxygen in the cover, and it will explode if it encounters an open flame.

[0031] 3. The water vapor inside the steel coil is not clean, which affects the product quality

[0033] However, according to the above-mentioned support plate of the steel strip coil is a blind plate, because the water vapor formed between the layers of the steel strip coil is larger than the proportion of the atmosphere in the bell type furnace, the water vapor between the layers of the steel strip coil will not go upward, but should go downward. Go, but there is no path downward, resulting in the accumulation of water vapor between the layers of the steel strip coil. At high temperature, the water oxidizes the surface of the steel strip, resulting in deterioration of product quality

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