High-surface-quality aluminum-zinc plated steel strip production device and production method

Abstract

The high-surface-quality aluminum-zinc-plated steel strip production device comprises a zinc pot, a corresponding furnace nose is arranged above the zinc pot, the furnace nose is obliquely arranged on one side of the zinc pot and forms a certain included angle with the vertical direction, the lower end of the furnace nose extends into an inner cavity of the zinc pot, and the upper end of the furnace nose inclines towards the outer side of the zinc pot and is externally connected with a corresponding annealing furnace; the height of the liquid level of the zinc liquid corresponds to the lower end of the furnace nose, a sinking roller, a stabilizing roller and a correcting roller which correspond to each other are further arranged in the zinc pot, the sinking roller is arranged in the zinc liquid corresponding to the lower end of the furnace nose, and the stabilizing roller and the correcting roller are arranged above the sinking roller and on the other side of the sinking roller corresponding to the furnace nose in a vertically staggered mode. The method is safer, more environmentally friendly and lower in energy consumption, and the production quality and economic benefits of the steel belt are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of hot-dip galvanizing, and in particular relates to a production method and a device for a high-surface-quality aluminum-zinc-plated steel strip. Background Art

[0002] As the competition in the steel industry becomes increasingly severe, the research and development of high value-added products is the main way for steel companies to get rid of development difficulties. Hot-dip galvanizing and its alloy products are one of the most common, effective and economical corrosion-resistant products in steel materials.

[0003] Taking aluminum-zinc coated steel strip as an example, hot-dip aluminum-zinc can effectively enhance the aesthetics of the steel strip surface and its corrosion resistance and durability. The existing hot-dip aluminum-zinc coating mostly uses molten 55% Al-43.4% Zn-1.6% Si plating solution as the production raw material during the production process. Due to the high melting point of the aluminum-zinc plating solution, the zinc pot temperature is generally controlled at around 600°C during normal production. However, the melting point of zinc is only 419°C. At high temperatures, zinc is easily volatilized in the form of steam. Zinc vapor will form zinc ash after condensation. If the zinc ash falls onto the strip, zinc ash defects will form on its plate surface. To address this type of defect, an electric heater is usually added to the furnace nose to heat the furnace nose to reduce the condensation of zinc vapor. However, the electric heater is a radiation heater with a low heating efficiency. The temperature in the north is low in winter, so it not only consumes a lot of energy, but also fails to achieve a good heating effect. As a result, the method of using an electric heater to heat the furnace nose is less effective in preventing the aluminum-zinc-coated steel strip from producing zinc ash defects. A large number of steel plates will also have zinc ash defects, seriously affecting the efficiency of strip production. Summary of the invention

[0004] The present invention aims to provide a production device and a production method for improving the surface quality of galvanized steel strips, so as to solve the technical problem that zinc ash defects are easily formed on the surface of galvanized steel strips during the existing production process.

[0005] To achieve the above purpose, the specific technical solutions of the present invention are as follows:

[0006] A device for producing high surface quality aluminum-zinc coated steel strips comprises a zinc pot, a corresponding furnace nose is arranged above the zinc pot, the furnace nose is inclined at a certain angle to the vertical direction and is arranged on one side of the zinc pot, the lower end of the furnace nose extends into the inner cavity of the zinc pot, and the upper end of the furnace nose is inclined toward the outside of the zinc pot and is externally connected to a corresponding annealing furnace, zinc liquid is arranged in the zinc pot, the liquid level of the zinc liquid corresponds to the lower end of the furnace nose, and corresponding sinking rollers, stabilizing rollers and correcting rollers are also arranged in the zinc pot, wherein the sinking roller is arranged in the zinc liquid corresponding to the lower end of the furnace nose, and the stabilizing roller and the correcting roller are arranged above the sinking roller and on the other side of the sinking roller corresponding to the furnace nose in an alternating manner.

[0007] Furthermore, a pair of air knives corresponding to the stabilizing roller and the correcting roller are provided above the stabilizing roller and the correcting roller.

[0008] Furthermore, the furnace nose comprises a furnace nose body and a heater, wherein the heater is arranged on the outer wall of the furnace nose body, the upper and lower ends of the furnace nose body are open, and the upper opening thereof is externally connected to the corresponding annealing furnace, and an insulating inner shell is added to the inner cavity of the furnace nose body, and the insulating inner shell is fixedly connected to the furnace nose body through the connecting plate on its outer side, and a hollow insulating layer is provided between the insulating inner shell and the furnace nose body.

[0009] Furthermore, the insulation layer is 5 cm thick and is filled with non-flammable insulation material.

[0010] Based on the above high surface quality galvanized steel strip production device, the present invention also provides a high surface quality galvanized steel strip production method, comprising the following steps:

[0011] Step 1: Add an appropriate amount of solid zinc to the zinc pot, start the zinc pot, and keep the temperature rising until it reaches the preset temperature and then stop. Maintain the temperature in the zinc pot at the preset temperature. During this process, the solid zinc in the zinc pot is completely melted into zinc liquid under the action of high temperature, and the liquid level of the zinc liquid is lower than the height of the upper mouth of the zinc pot.

[0012] Step 2: Start the heater of the furnace nose so that the inner cavity of the furnace nose reaches and maintains the preset temperature;

[0013] Step 3: The pretreated steel strip continuously passes through the furnace nose 2 from its free end, and enters the zinc liquid in the zinc pot through its lower opening for hot-dip galvanizing;

[0014] Step 4: The hot-dip galvanized steel strip starts to leave the zinc pot from its free end. As the front end of the hot-dip galvanized steel strip 7 leaves, its rear end synchronously and automatically enters the zinc pot for hot-dip galvanizing.

[0015] Step 5: The steel strip leaving the zinc pot passes between two corresponding air knives above the zinc liquid.

[0016] Furthermore, the temperature of the zinc liquid in the zinc pot is heated and maintained at 580°C.

[0017] Further, the temperature in the furnace nose is heated and maintained at 620°C.

[0018] The high surface quality aluminum-zinc-plated steel strip production device and production method of the present invention have lower energy consumption, are more energy-saving and environmentally friendly, and the zinc ash defect rate on the surface of the steel strip produced thereby is lower and the qualified rate of the surface quality is higher, thereby improving the economic benefits of the steel strip production. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a working schematic diagram of the production device of high surface quality aluminum-zinc coated steel strip of the present invention;

[0020] Figure 2 For the present invention Figure 1Schematic diagram of the cross-sectional structure of the middle furnace nose;

[0021] Explanation of the markings in the figure: 1. Zinc pot; 11. Zinc liquid; 2. Furnace nose; 21. Furnace nose body; 22. Heater; 23. Insulation inner shell; 24. Insulation layer; 3. Sinking roller; 4. Stabilizing roller; 5. Correction roller; 6. Air knife; 7. Steel strip. DETAILED DESCRIPTION

[0022] In order to better understand the purpose, structure and function of the present invention, the following is a further detailed description of a method for producing a high surface quality aluminum-zinc coated steel strip 7 and a production device thereof in conjunction with the accompanying drawings.

[0023] like Figure 1-2 As shown, the production device of high surface quality aluminum-zinc coated steel strip of the present invention comprises a zinc pot 1, a corresponding furnace nose 2 is arranged above the zinc pot 1, the furnace nose 2 is arranged on one side of the zinc pot 1, and is inclined at a certain angle to the vertical direction, and its upper end is inclined to the outside of the zinc pot 1, and is externally connected to a corresponding annealing furnace, and the lower end of the furnace nose 2 extends into the inner cavity of the zinc pot 1, and zinc liquid 11 is arranged in the zinc pot 1, and the liquid level of the zinc liquid 11 corresponds to the lower end of the furnace nose 2, and the lower end of the furnace nose 2 is not higher than the liquid level of the zinc liquid 11, and the pretreated steel strip 7 passes through the inner cavity of the furnace nose body 21 and then enters the zinc pot 1 for hot-dip aluminum-zinc, and the zinc pot 1 is also provided with a sinking roller 3, a stabilizing roller 4 and a correcting roller 5 corresponding to each other. When working, the three All of them are immersed in the zinc liquid, wherein the sinking roller 3 is arranged in the zinc liquid 11 corresponding to the lower end of the furnace nose 2, and the stabilizing roller 4 and the correcting roller 5 are arranged above the sinking roller 3, and the two are located on the other side of the sinking roller 3 corresponding to the furnace nose 2, and the two are staggered up and down, and the gap between the horizontal projections of the two is tangent to the projection of the sinking roller 3. After the steel strip 7 enters the zinc pot 1 from the furnace nose 2, it bypasses the sinking roller 3, and then bypasses from the inner side opposite to the stabilizing roller 4 and the correcting roller 5, passes through the zinc liquid 11, and leaves the zinc pot 1. While providing support for the steel strip 7, it also changes the forward direction of the steel strip 7, and it cooperates with the stabilizing roller 4 and the correcting roller 5 to correct the direction of the steel strip 7 leaving the zinc pot 1, making its continuous forward operation more stable.

[0024] Furthermore, an air knife 6 is provided above the stabilizing roller 4 and the correcting roller 5. A pair of air knives 6 corresponding to the two are respectively provided above the stabilizing roller 4 and the correcting roller 5. After the steel strip 7 leaves the zinc pot 1, it passes through the gap between the two air knives 6. The air knife 6 can blow off excess plating liquid on the surface of the steel strip 7 to prevent the surface coating of the steel strip 7 from being too thick and affecting its quality.

[0025] Furthermore, the furnace nose 2 includes a furnace nose body 21 and a heater 22, wherein the heater 22 is arranged on the outer wall of the furnace nose body 21, the upper and lower ends of the furnace nose body 21 are open, and the upper opening thereof is externally connected to the corresponding annealing furnace, and an insulating inner shell 23 is added to the inner cavity of the furnace nose body 21, and the insulating inner shell 23 is fixedly connected to the furnace nose body 21 through the connecting plate on its outer side. In this embodiment, the connecting plate is arranged at the bottom of the insulating inner shell 23, and its outer end is connected to the inner wall of the furnace nose body 21, and a hollow insulating layer 24 is provided between the insulating inner shell 23 and the furnace nose body 21. The setting of the insulating inner shell 23 not only improves the insulating performance of the furnace nose 2, but also can reduce the energy consumption of the heater 22 during heating.

[0026] Furthermore, the insulation layer 24 between the insulation inner shell 23 and the furnace nose body 21 is 5 cm thick, and the insulation layer 24 is filled with non-flammable insulation material. In this embodiment, heat-resistant insulation cotton is used to fill the insulation layer 24, which can effectively reduce the temperature fluctuation in the furnace nose body 21 caused by heat loss.

[0027] The present invention also provides a method for producing a high surface quality galvanized steel strip based on the above high surface quality galvanized steel strip production device, the steps of which include:

[0028] The first step is to add a proper amount of solid zinc to the zinc pot 1, start the zinc pot 1, and the heating device of the zinc pot 1 starts to work on the solid zinc. The temperature in the zinc pot 1 continues to rise until it reaches its preset temperature and stops, and the heating device continues to work so that the temperature in the zinc pot 1 is maintained at the preset temperature. In this process, the solid zinc in the zinc pot 1 is completely melted into zinc liquid 11 under the action of high temperature. The liquid level of the zinc liquid 11 corresponds to the lower opening of the furnace nose body 21 and is lower than the upper opening of the zinc pot 1, so as to prevent the zinc liquid 11 in the zinc pot 1 from overflowing and causing damage to the surrounding environment and harm to the staff.

[0029] Step 2: Start the heater 22 of the furnace nose 2 to heat the furnace nose 2 so that the inner cavity of the furnace nose 2 reaches and maintains a preset temperature;

[0030] Step 3: The pretreated steel strip 7 continuously passes through the furnace nose 2 from its free end and penetrates into the zinc liquid 11 in the zinc pot 1 through its lower opening. The zinc liquid 11 in the zinc pot 1 reacts with the penetrated steel strip 7 to form a hot-dip galvanizing layer on its surface.

[0031] Step 4: the hot-dip galvanized steel strip 7 leaves the zinc pot 1. In this embodiment, when the free end of the steel strip 7 enters the zinc pot 1, the staff of each component in the zinc pot 1 use corresponding tools to guide the free end of the steel strip 7 so that it bypasses the sinking roller 3, the stabilizing roller 4 and the correcting roller 5 respectively and leaves the zinc liquid 11. When the front end of the hot-dip galvanized steel strip 7 leaves the zinc pot 1, its rear end synchronously and continuously enters the zinc pot 1 for hot-dip galvanizing reaction, so that the galvanizing of the steel strip 7 becomes continuous and uninterrupted, making the hot-dip galvanizing efficiency of the steel strip 7 higher.

[0032] Step 5: The steel strip 7 leaving the zinc pot 1 passes through the gap between the two corresponding air knives 6 above the zinc liquid 11, thereby leaving the hot-dip galvanized steel strip 7 production device.

[0033] Furthermore, the temperature of the zinc liquid 11 in the zinc pot 1 is heated and maintained at 580° C., which is lower than the temperature of the existing zinc pot 1 , thereby reducing the volatilization of zinc vapor and thereby reducing the formation of zinc ash.

[0034] Furthermore, the heater 22 heats the temperature in the furnace nose 2 to 620° C. and maintains it at this temperature, which is higher than the temperature of the zinc pot, thereby reducing the pre-condensation rate of zinc vapor and thereby reducing the formation of zinc ash.

[0035] The device and method for producing high surface quality aluminum-zinc-coated steel strip 7 of the present invention reduces the volatilization of the zinc liquid 11 inside the zinc pot 1 by controlling the temperature of the zinc pot 1, thereby reducing the formation of zinc vapor, and reduces the condensation rate of zinc vapor by insulating and controlling the temperature of the furnace nose 2. The two cooperate with each other to greatly reduce the generation rate of zinc ash, thereby greatly reducing the probability of zinc ash causing defects on the surface of the steel strip 7, so that the surface quality of the steel strip 7 produced by using the production device and method of the present invention can be better guaranteed, and the qualified rate of the steel strip 7 is higher. At the same time, the setting of the insulation layer 24 of the furnace nose 2 reduces the temperature dissipation rate, which not only improves the insulation effect of the furnace nose 2, but also reduces the energy consumption loss of the heater 22, thereby improving the economic benefits of the production of the steel strip 7.

[0036] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A device for producing high surface quality galvanized steel strip, characterized in that: The invention comprises a zinc pot (1), a corresponding furnace nose (2) is arranged above the zinc pot (1), the furnace nose (2) is arranged on one side of the zinc pot (1) at a certain angle to the vertical direction, the lower end of the furnace nose (2) extends into the inner cavity of the zinc pot (1), and the upper end of the furnace nose (2) is inclined toward the outside of the zinc pot (1) and externally connected to a corresponding annealing furnace, a zinc liquid (11) is arranged in the zinc pot (1), the liquid level of the zinc liquid (11) corresponds to the lower end of the furnace nose (2), and the zinc pot (1) is also provided with corresponding sinking rollers (3), stabilizing rollers (4) and correcting rollers (5), wherein the sinking rollers (3) are arranged in the zinc liquid (11) corresponding to the lower end of the furnace nose (2), and the stabilizing rollers (4) and the correcting rollers (5) are arranged in an upper and lower staggered manner above the sinking rollers (3) and on the other side of the sinking rollers (3) corresponding to the furnace nose (2).

2. The high surface quality galvanized steel strip production device according to claim 1 is characterized in that: A pair of air knives (6) corresponding to the stabilizing roller (4) and the correcting roller (5) are provided above the stabilizing roller (4) and the correcting roller (5).

3. The high surface quality galvanized steel strip production device according to claim 1 is characterized in that: The furnace nose (2) comprises a furnace nose body (21) and a heater (22), wherein the heater (22) is arranged on the outer wall of the furnace nose body (21), the upper and lower ends of the furnace nose body (21) are open, and the upper opening is externally connected to a corresponding annealing furnace, and an insulating inner shell (23) is added to the inner cavity of the furnace nose body (21), and the insulating inner shell (23) is fixedly connected to the furnace nose body (21) through a connecting plate on its outer side, and a hollow insulating layer (24) is provided between the insulating inner shell (23) and the furnace nose body (21).

4. The high surface quality galvanized steel strip production device according to claim 3 is characterized in that: The insulation layer (24) is 5 cm thick and is filled with non-flammable insulation material.

5. The method for producing a high surface quality galvanized steel strip according to any one of claims 1 to 4, characterized in that: It includes the following steps: The first step is to add a proper amount of solid zinc into the zinc pot (1), start the zinc pot (1), and continuously raise the temperature thereof until it reaches a preset temperature and then stop, and maintain the temperature in the zinc pot (1) at the preset temperature. During this process, the solid zinc in the zinc pot (1) is completely melted into zinc liquid (11) under the action of high temperature, and the liquid level of the zinc liquid (11) is lower than the height of the upper opening of the zinc pot (1); Step 2: Start the heater (22) of the furnace nose (2) so that the inner cavity of the furnace nose (2) reaches and maintains a preset temperature; Step 3: The pre-treated steel strip (7) continuously passes through the furnace nose (2) from its free end and enters the zinc liquid (11) in the zinc pot (1) through its lower opening for hot-dip galvanizing; Step 4: the hot-dip galvanized steel strip (7) starts to leave the zinc pot (1) from its free end, and as the front end of the hot-dip galvanized steel strip (7) leaves, its rear end synchronously and automatically enters the zinc pot (1) for hot-dip galvanizing; Step 5: The steel strip (7) leaving the zinc pot (1) passes between two corresponding air knives (6) above the zinc liquid (11).

6. The method for producing high surface quality galvanized steel strip according to claim 5, characterized in that: The temperature of the zinc liquid (11) in the zinc pot (1) is heated and maintained at 580°C.

7. The method for producing high surface quality galvanized steel strip according to claim 5, characterized in that: The temperature inside the furnace nose (2) is heated and maintained at 620°C.

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