Humidifying gas injection device for annealing furnace

Abstract

This utility model relates to the field of continuous processing furnaces for heat treatment of strips or wires, specifically a humidifying gas injection device for an annealing furnace. The device includes an annealing furnace, a pre-oxidation humidification chamber, injection pipes, and nozzles. An exhaust fan is installed inside the pre-oxidation humidification chamber. One end of a heat-tracing and insulation main pipe is connected to the outlet of the exhaust fan inside the pre-oxidation humidification chamber, and the other end of the main pipe is connected to the inlets of two heat-tracing and insulation branch pipes. The two injection pipes are rotatably mounted on two opposite inner sidewalls of the annealing furnace chamber via bearings and are parallel to each other. The outlet of each heat-tracing and insulation branch pipe is rotatably fitted with the inlet of one injection pipe. The other end of each injection pipe is closed. Each injection pipe has at least five nozzles arranged axially. This application provides uniform moisture diffusion and stable humidification effect.

Description

Technical Field

[0001] This utility model relates to the field of continuous processing furnaces for heat treatment of strips or wires, specifically a humidifying gas injection device for an annealing furnace. Background Technology

[0002] With the continuous improvement of people's living standards and the increasing production of automobiles, pressures related to environmental protection, energy conservation, and lightweighting have also arisen. How to reduce the weight of automobiles while maintaining the strength of the steel panels is a pressing problem for the automotive industry. Advanced high-strength steels used in automobiles mainly include: dual-phase steel (DP steel), multiphase steel (CP steel), martensitic steel, transformation-induced plasticity steel (TRIP steel), and twin-induced plasticity steel (TWIP steel). The microstructure of dual-phase steel (DP steel) mainly consists of a soft ferrite matrix and hard island-like martensite, and may also contain a small amount of bainite or retained austenite. This type of steel exhibits good strength, toughness, and formability.

[0003] Currently, in continuous annealing furnace processes, adding a humidification device to the annealing furnace is the main method to control the quantity and type of oxides generated on the surface of the strip steel. The more water molecules in the gas inside the annealing furnace, the higher the dew point, and the stronger the oxidizing power of the atmosphere. Studies have shown that as the dew point increases, the selective oxidation mode of alloying elements in the steel plate inside the annealing furnace changes from external oxidation to internal oxidation, thereby reducing the oxides on the strip steel surface.

[0004] However, the different methods of injecting humidifying atmosphere into the furnace also bring some additional problems during the production process, such as excessive local oxidation, unreducible oxidation color on the surface, and poor plating properties. Utility Model Content

[0005] In order to overcome the shortcomings of the prior art, and to provide a processing furnace auxiliary device with uniform moisture diffusion and stable humidification effect, this utility model discloses a humidification gas injection device for an annealing furnace.

[0006] This utility model achieves its invention objective through the following technical solution: A humidifying gas injection device for an annealing furnace, comprising an annealing furnace, characterized in that it further comprises a pre-oxidation humidifying chamber, an insulated heat tracing main pipe, insulated heat tracing branch pipes, an injection pipe, and nozzles. The pre-oxidation humidification chamber is equipped with an exhaust fan and stores nitrogen and water vapor as humidifying gas. One end of the heat-tracing main pipe is connected to the outlet of the exhaust fan in the pre-oxidation humidification chamber, and the other end of the heat-tracing main pipe is connected to the inlet of two heat-tracing branch pipes. The two ends of the two spray pipes are rotatable and parallel to each other on two opposite inner walls of the annealing furnace. A plane located in the middle of the two spray pipes serves as the conveying surface of the strip steel. The outlet of each heat-tracing branch pipe is rotatably fitted with the inlet of a spray pipe. The other end of the spray pipe is closed and sealed to prevent the humidifying gas from leaking out. Each spray pipe has at least five nozzles arranged axially. The spraying directions of the nozzles on the two spray pipes are directly opposite each other. The airflow sprayed by the nozzles covers the movement path of the strip steel in the annealing furnace.

[0007] Preferably, the humidifying gas injection device for the annealing furnace further includes a regulating valve and a flow meter, with a regulating valve and a flow meter connected in series on each heat-tracing branch pipe.

[0008] Preferably, the humidifying gas injection device for the annealing furnace further includes an adjusting handle, with an adjusting handle fitted at the inlet of each injection pipe.

[0009] Preferably, the nozzles are evenly distributed at intervals along the axial direction of the spray pipe.

[0010] Preferably, the angle between the central axis of the fan-shaped area formed by the nozzle and the conveying surface, i.e., the strip steel, is adjustable within the range of 0 to 45° ± 10°.

[0011] When this utility model is used, the strip steel is fed into the furnace chamber of the annealing furnace and moves between two spray pipes. The air pump in the pre-oxidation humidification box draws in the humidification gas and sprays the humidification gas through the heat-insulating main pipe, the heat-insulating branch pipe and the spray pipe in sequence, and then sprays it onto the strip steel from the nozzle, so that the outer surface of the strip steel produces a uniform pre-oxidation effect.

[0012] This invention can also employ high-precision regulating valves and flow meters to more accurately control the flow rate and pressure of the humidifying gas injected into the annealing furnace, preventing excessive pressure of the injected humidifying gas from blowing water directly onto the outer surface of the strip steel, thereby causing localized oxidation.

[0013] This invention also allows for adjustment of the handle to control the angle between the central axis of the fan-shaped area formed by the nozzle spray and the conveying surface, i.e., the strip steel. The adjustment range is up to 45°±10°, thereby better controlling the uniformity of the strip steel pre-oxidation.

[0014] This invention has the following advantages: it enables the pre-oxidation and humidification equipment in the annealing furnace to achieve a more stable humidification effect; compared with the previous direct-flow single-sided injection of humidification atmosphere, the humidification atmosphere diffuses more evenly, preventing local over-oxidation and the appearance of oxidation before it occurs in another part, thus ensuring uniform pre-oxidation throughout the annealing furnace. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a left-side view of the annealing furnace in this utility model. Detailed Implementation

[0016] The present invention will be further illustrated by specific embodiments below. Example

[0017] A humidifying gas injection device for an annealing furnace includes an annealing furnace 1, a pre-oxidation humidifying chamber 2, a main heat-tracing pipe 31, a branch heat-tracing pipe 32, an injection pipe 4, and a nozzle 41, such as Figure 1 and Figure 2 As shown, the specific structure is: The pre-oxidation humidification chamber 2 is equipped with an exhaust fan and stores nitrogen and water vapor as humidifying gas. One end of the heat-insulating and heat-tracing main pipe 31 is connected to the outlet of the exhaust fan in the pre-oxidation humidification chamber 2, and the other end of the heat-insulating and heat-tracing main pipe 31 is connected to the inlet of two heat-insulating and heat-tracing branch pipes 32 respectively. The two ends of the two spray pipes 4 are rotatably mounted on the two inner side walls opposite each other in the furnace chamber of the annealing furnace 1 through bearings. A plane located in the middle of the two spray pipes 4 serves as the conveying surface of the strip steel 7. The outlet of each heat-insulating and heat-tracing branch pipe 32 is rotatably fitted with the inlet of a spray pipe 4. The other end of the spray pipe 4 is closed and sealed to prevent the humidifying gas from leaking out. Each spray pipe 4 is provided with at least five nozzles 41 in sequence along the axial direction. The spraying directions of each nozzle 41 on the two spray pipes 4 are directly opposite each other. The airflow sprayed by the nozzles 41 covers the movement path of the strip steel 7 in the furnace chamber of the annealing furnace 1.

[0018] This embodiment also includes a regulating valve 51 and a flow meter 52, with a regulating valve 51 and a flow meter 52 connected in series on each heat-insulated branch pipe 32.

[0019] This embodiment also includes an adjustment handle 6, with an adjustment handle 6 installed at the inlet of each spray pipe 4.

[0020] In this embodiment, after the strip steel 7 is fed into the furnace chamber of the annealing furnace 1, it moves between the two injection pipes 4. The exhaust fan in the pre-oxidation humidification box 2 draws in the humidification gas, and sprays the humidification gas sequentially through the heat-insulating and heat-tracing main pipe 31, the heat-insulating and heat-tracing branch pipe 32 and the injection pipe 4, and then sprays it onto the strip steel 7 from the nozzle 41, so that the outer surface of the strip steel 7 produces a uniform pre-oxidation effect.

[0021] This embodiment also employs a high-precision regulating valve 51 and a flow meter 52 to more accurately control the flow rate and pressure of the humidifying gas injected into the furnace chamber of the annealing furnace 1, preventing the pressure of the injected humidifying gas from being too high and blowing water directly onto the outer surface of the strip steel 7, thereby forming an oxide color locally.

[0022] In this embodiment, the angle between the central axis of the fan-shaped area formed by the nozzle (41) and the conveying surface, i.e., the strip 7, can be controlled by adjusting the handle 6. The adjustment range is 45°±10°. This allows for better control of the uniformity of the pre-oxidation of the strip 7.

Claims

1. A moistening gas injection device of an annealing furnace, comprising an annealing furnace (1), characterized by: It also includes a pre-oxidation humidification chamber (2), an insulated heat tracing main pipe (31), an insulated heat tracing branch pipe (32), a jet pipe (4), and a nozzle (41). The pre-oxidation humidification box (2) is equipped with an air extractor and stores humidifying gas. One end of the heat-insulating and heat-tracing main pipe (31) is connected to the outlet of the air extractor in the pre-oxidation humidification box (2). The other end of the heat-insulating and heat-tracing main pipe (31) is connected to the inlet of two heat-insulating and heat-tracing branch pipes (32). The two ends of the two spray pipes (4) are rotatable and parallel to each other on the two inner side walls of the furnace chamber of the annealing furnace (1). A plane located in the middle of the two spray pipes (4) serves as the conveying surface of the strip steel (7). The outlet of each heat-insulating and heat-tracing branch pipe (32) is rotatably fitted with the inlet of a spray pipe (4). The other end of the spray pipe (4) is closed and sealed. Each spray pipe (4) is provided with at least five nozzles (41) in sequence along the axial direction. The spraying directions of each nozzle (41) on the two spray pipes (4) are directly opposite each other.

2. The humidified gas injection apparatus of the annealing furnace according to claim 1, characterized by: It also includes a regulating valve (51) and a flow meter (52), with a regulating valve (51) and a flow meter (52) connected in series on each heat-insulated branch pipe (32).

3. The moistening gas injection apparatus of the annealing furnace according to claim 1 or 2, characterized by: It also includes an adjustment handle (6), with an adjustment handle (6) installed at the inlet of each spray pipe (4).

4. The humidified gas injection apparatus of claim 3, wherein: The nozzles (41) are evenly distributed along the axial spacing of the injection pipe (4).

5. The apparatus for injecting a humidified gas into an annealing furnace according to claim 4, wherein: The angle between the central axis of the fan-shaped area formed by the nozzle (41) and the conveying surface can be adjusted from 0 to 45° ± 10°.

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