A device for controlling the zinc coating thickness of galvanized steel coils

Abstract

This utility model discloses a zinc layer thickness control device for galvanized steel coils, comprising two sets of parallel air knife assemblies arranged above a galvanizing tank. The air knife holes of the air knife assemblies are arranged adjacent to each other, and the air knife assemblies are connected to a nitrogen cylinder via a compressor. The two sets of air knife assemblies are distributed on both sides of the steel coil and blow away the zinc liquid on the surface of the steel coil. Both ends of the two sets of air knife assemblies are supported on a support frame, which is installed on the galvanizing tank and controls the relative movement of the air knife assemblies. This utility model is equipped with air knife assemblies and an X-ray thickness gauge. When the steel coil immersed in zinc liquid passes through the space formed by the two sets of air knife assemblies, the airflow blown by the air knife assemblies removes excess zinc liquid from the surface of the steel coil, controlling the thickness of the zinc layer. Then, the X-ray thickness gauge monitors the thickness of the zinc layer in real time and transmits the information to the control system. The control system analyzes the information and decides whether to adjust the position of the air knife assemblies to clean the zinc liquid adhering to the surface of the steel coil in a timely manner and control the thickness of the zinc layer.

Description

Technical Field

[0001] This utility model relates to the field of zinc coating technology for steel coils, specifically a device for controlling the thickness of the zinc coating on galvanized steel coils. Background Technology

[0002] In the steel coil processing industry, galvanizing is a key process for improving the corrosion resistance of steel. Its core principle is to isolate the steel from corrosive media through the sacrificial anodic protection or the formation of a passivation film by the zinc layer. However, the thickness of the zinc layer directly affects the product's performance, cost, and adaptability to subsequent processing. Therefore, precise control of the zinc layer thickness has become a core aspect of the galvanizing production process.

[0003] From a product performance perspective, improper control of the galvanized layer thickness can lead to a series of problems. Insufficient thickness means the coating cannot completely cover the steel coil surface, making it prone to damage during transportation and use due to friction and impact. This exposes the steel to corrosive environments such as moisture, acids, and alkalis, significantly shortening its service life. For example, outdoor construction color-coated substrates with an excessively thin coating may show signs of corrosion within 1-2 years. Conversely, while excessive thickness can improve corrosion resistance to some extent, it increases the brittleness of the zinc layer. During subsequent bending, stamping, and other processing stages, the coating is highly susceptible to cracking and peeling, thus losing its protective function for the steel. Furthermore, the galvanized layer thickness also affects the overall mechanical properties of the steel coil, especially its formability. A thinner coating bonds more tightly to the substrate, suitable for applications requiring deep drawing and high-frequency bending, such as automotive body panels, reducing the risk of coating peeling from the steel. Conversely, an unevenly distributed thick coating can cause localized differences in hardness within the steel coil, leading to deformation or breakage during rolling and cutting due to uneven stress.

[0004] In terms of production costs, zinc, as the main raw material in the galvanizing process, accounts for 20%-30% of the production cost of galvanized steel coils. Excessively thickening the coating directly increases zinc consumption, leading to higher costs. It is estimated that for every 10μm increase in zinc layer thickness per square meter of steel coil, zinc consumption per ton of steel coil increases by approximately 8-10kg (zinc density is approximately 7.14g / cm³). Based on a zinc price of 20,000 yuan per ton, this translates to an increase of 160-200 yuan per ton of steel coil. Furthermore, improper thickness control can lead to rework; for example, a coating that is too thin requires re-plating, while a coating that is too thick requires grinding. This further increases labor and energy consumption, reducing production efficiency.

[0005] Therefore, the zinc layer thickness needs to be controlled during the galvanizing process of steel coils to avoid the aforementioned problems as much as possible. Utility Model Content

[0006] The purpose of this invention is to provide a zinc layer thickness control device for galvanized steel coils, which aims to improve the problem of insufficient corrosion resistance or high galvanizing cost caused by the inconvenience of controlling the zinc layer thickness.

[0007] This invention is implemented as follows: A zinc layer thickness control device for galvanized steel coils includes two sets of parallel air knife assemblies arranged above a galvanizing tank. The air knife holes of the air knife assemblies are arranged adjacent to each other, and the air knife assemblies are connected to a nitrogen cylinder via a compressor. The two sets of air knife assemblies are distributed on both sides of the steel coil and blow away the molten zinc on the surface of the steel coil. Both ends of the two sets of air knife assemblies are supported on a support frame, which is installed on the galvanizing tank and controls the relative movement of the air knife assemblies. An X-ray thickness gauge is detachably installed on the side of one of the support frames, and the X-ray source and X-ray detector of the X-ray thickness gauge detect the zinc layer thickness.

[0008] Preferably, the air knife assembly includes an outer tube, a gas output chamber arranged along the length of the outer tube and connected to the outer tube, and end tubes respectively installed at both ends of the outer tube; the end of one end tube is closed, and the air knife hole is located on the gas output chamber.

[0009] Preferably, an inner tube and a middle tube are arranged sequentially from the inside to the outside on the inner side of the outer tube. A set of air holes is provided on the side wall of both the inner tube and the middle tube. The two sets of air holes are arranged far apart, and the air holes of the inner tube are arranged close to the gas output chamber.

[0010] Preferably, the gas output from the end pipe enters the inner pipe and then exits through the vent to fill the middle pipe, and the gas in the middle pipe exits through the vent to fill the outer pipe.

[0011] Preferably, an air chamber is provided inside the gas output chamber, and the air knife hole is located at the edge of the air chamber away from the outer tube, and the size of the end of the air chamber near the outer tube is larger than the size of the other end.

[0012] Preferably, the support frame includes two sets of support plates and two bearing seats mounted on each set of support plates. Two sets of air knife assemblies are arranged between the two sets of support plates, and the end tube of each set of air knife assemblies passes through the bearing seat. At the same time, the bearing seat is slidably arranged on the support plate.

[0013] Preferably, a guide rail is fixedly installed on the support plate along its length, and four sliders are sleeved on the guide rail. A threaded post is vertically installed on each slider. The four sliders are evenly distributed below the two bearing seats, and the threaded post penetrates through the bearing seat.

[0014] Preferably, two threaded rods with opposite thread directions are connected to the side of the support plate, and a threaded sleeve is fitted on each threaded rod. The two threaded sleeves are respectively installed on the sliders below the two bearing seats. A drive shaft is provided between the two support plates. The drive shaft is connected to the power output shaft of the motor, and the second bevel gear installed at the end of the drive shaft meshes with the first bevel gear of the threaded rod.

[0015] Preferably, two end pipes located on the same support plate are connected by a flexible hose, and a solenoid valve is provided at the front end of the junction of one end pipe and the flexible hose, and the solenoid valve is connected to the compressor.

[0016] Preferably, a brake disc is fitted onto the end tube, and multiple brake holes are evenly distributed along the circumference of the edge of the brake disc; a limit bolt is threaded through the threaded hole at the top of the bearing housing, and the end of the limit bolt is inserted into a certain brake hole.

[0017] The beneficial effects of this utility model are:

[0018] 1. This utility model is equipped with an air knife assembly and an X-ray thickness gauge. When a steel coil immersed in zinc liquid passes through the space formed by two sets of air knife assemblies, the airflow blown out by the air knife assembly removes excess zinc liquid from the surface of the steel coil and controls the thickness of the zinc layer. Then, the X-ray thickness gauge monitors the thickness of the zinc layer in real time and transmits the information to the control system. The control system analyzes the information and decides whether to adjust the position of the air knife assembly to clean the zinc liquid adhering to the surface of the steel coil in a timely manner and control the thickness of the zinc layer.

[0019] 2. The air knife assembly of this utility model is supported on a support frame, and the support frame is installed on the galvanizing tank. At the same time, the support frame can control the movement of the air knife assembly, and the position of the air knife assembly can be adjusted under the operation of the control system to realize the adjustment and control of the zinc layer thickness. Attached Figure Description

[0020] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model, making other features, objects, and characteristics of the utility model more apparent. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model.

[0021] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0022] Figure 2 This is a structural schematic diagram of the air knife assembly and support frame of this utility model;

[0023] Figure 3 This is a first structural schematic diagram of the air knife assembly of this utility model;

[0024] Figure 4 This is a schematic diagram of the second structure of the air knife assembly of this utility model;

[0025] Figure 5 This is a schematic diagram of the third structure of the air knife assembly of this utility model;

[0026] Figure 6 This is a structural schematic diagram of the support frame of this utility model;

[0027] Figure 7 This is a structural schematic diagram of the support plate, bearing seat, and end tube of this utility model;

[0028] Figure 8 This is a schematic diagram of the structure of the support plate of this utility model;

[0029] Figure 9 This is a structural schematic diagram of the bearing housing and end tube of this utility model.

[0030] In the diagram: 1. Gas tank; 2. Compressor; 3. Air knife assembly; 31. Outer pipe; 32. Gas output chamber; 33. End pipe; 33. Brake disc; 331. Brake hole; 332. Intermediate pipe; 34. Inner pipe; 35. Air hole; 36. Air chamber; 37. Air knife hole; 38. Support frame; 4. Support plate; 41. Guide rail; 412. Slider; 413. Threaded column; 414. Threaded rod; 415. Threaded sleeve; 416. First bevel gear; 42. Motor; 43. Hose; 44. Drive shaft; 45. Second bevel gear; 46. Bearing seat; 461. Threaded hole; 462. Limit bolt; 47. Solenoid valve; 5. X-ray thickness gauge; 51. X-ray source; 52. X-ray detector. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0032] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0033] In order to promptly remove excess zinc liquid adhering to the surface of steel coils after galvanizing in the galvanizing bath, control the thickness of the zinc layer, and reduce galvanizing costs while meeting corrosion resistance requirements, this embodiment provides a zinc layer thickness control device. The device is installed on the galvanizing bath, and the steel coils detached from the galvanizing bath pass through the device. The device then blows away the zinc liquid adhering to the surface of the steel coils, while simultaneously monitoring the zinc layer thickness in real time so that the status of the control device can be adjusted in a timely manner if any abnormalities occur.

[0034] like Figure 1 , Figure 2As shown, specifically, the device includes two parallel air knife assemblies 3, a support frame 4, and an X-ray thickness gauge 5. The support frame 4 is installed on the galvanizing tank, with both ends of the two air knife assemblies 3 supported on the support frame 4, and the two air knife assemblies 3 distributed on both sides of the steel coil. The support frame 4 controls the relative movement of the air knife assemblies 3, allowing adjustment of their positions when abnormal zinc layer thickness occurs. Furthermore, the air knife assemblies 3 are connected to a nitrogen tank 1 via a compressor 2. When the compressor 2 is operating, nitrogen is drawn and delivered to the air knife assemblies 3. The air knife assemblies 3 then spray compressed air onto the surface of the steel coil according to preset parameters to remove excess molten zinc.

[0035] like Figure 1 , Figure 2 As shown, the X-ray thickness gauge 5 is also mounted on the support frame 4, and the X-ray source 51 and X-ray detector 52 of the X-ray thickness gauge 5 detect the thickness of the zinc layer. At the same time, the X-ray thickness gauge 5 and the support frame 4 are both connected to the same control system. During the process of removing excess zinc liquid by the air knife assembly 3, the X-ray thickness gauge 5 detects the thickness of the zinc layer on the surface of the steel coil in real time and transmits the data to the control system.

[0036] An X-ray source typically consists of an X-ray tube, a high-voltage generator, and a filament circuit. For normal operation, an X-ray thickness gauge also requires a corresponding driver, standard sample box, main electrical cabinet, signal processing and calculation unit, and cooling system. The driver is primarily used to precisely control the high voltage and current of the X-ray source, ensuring stable X-ray emission. The standard sample box is mainly used for the calibration and measurement operations of the thickness gauge. The main electrical cabinet, as the control center of the X-ray thickness gauge, houses numerous electrical components, including the main computer system, various input / output signal acquisition / isolation driver boards, and power supplies. The electrical signal output from the detector is first transmitted to the signal processing unit, where it undergoes a series of processes such as amplification and filtering to remove noise interference and improve signal quality and stability. Subsequently, the processed signal is transmitted to the calculation unit. The calculation unit, combining the known attenuation coefficient of the zinc layer material to X-rays and pre-stored calibration data, uses a specific algorithm to perform real-time calculations on the signal, thereby obtaining an accurate zinc layer thickness value, which is then fed back to the control system of the entire steel coil zinc layer thickness control device.

[0037] The control system employs a combination of an industrial computer and a programmable logic controller (PLC) for intelligent control of the entire device. The control system receives zinc layer thickness data from the X-ray thickness gauge 5, analyzes and processes it, and then sends control commands to the support frame 4 to precisely adjust the air knife assembly 3. The control system also features data storage and display functions, capable of displaying zinc layer thickness, air knife operating parameters, and other information in real time, while storing historical data in a database for subsequent retrieval and analysis. Through the human-machine interface, operators can easily set target zinc layer thickness values, initial air knife parameters, and perform real-time monitoring and fault diagnosis of the equipment's operating status.

[0038] like Figure 3-5 As shown, the air knife assembly 3 includes an outer tube 31, a middle tube 34, an inner tube 35, a gas output chamber 32, and two end tubes 33. The outer tube 31, middle tube 34, and inner tube 35 are arranged sequentially from the outside to the inside, forming three concentric spaces within the outer tube 31. Simultaneously, a set of air holes 36 are provided on the side walls of the middle tube 34 and the inner tube 35, respectively, thus connecting the three spaces. A through hole is provided on the side wall of the outer tube 31, and the gas output chamber 32 is installed on the outside of the outer tube 31 and connected to the through hole. Therefore, the three spaces within the outer tube 31 are connected to the gas output chamber 32, providing a curved channel for gas flow.

[0039] like Figure 3-5 As shown, two end pipes 33 are mechanically sealed at both ends of the outer pipe 31, and the two end pipes 33 are supported on the support frame 4. At the same time, the end of one end pipe 33 away from the outer pipe 31 is blocked, and the other end pipe 33 is connected to the compressor 2. When the compressor 2 is working, nitrogen gas can be drawn into the inner pipe 35, and then flows through the gas hole 36 twice to the outermost space. Finally, it flows into the gas output chamber 32 through the through hole and is output from the gas knife hole 38 at the edge of the gas output chamber 32 to form a gas knife.

[0040] like Figure 5 As shown, to further increase the gas output flow rate, a gas chamber 37 is provided inside the gas output chamber 32. The gas knife hole 38 is located at the edge of the gas chamber 37 away from the outer tube 31, and the dimension of the end of the gas chamber 37 adjacent to the outer tube 31 is larger than the dimension of the other end. By utilizing the structural characteristics of the gas chamber 37, the gas is concentrated in the gas chamber 37, which increases the gas pressure at this location and increases the gas output rate.

[0041] like Figure 6 , Figure 7As shown, to ensure the stable and adjustable mounting of the two air knife assemblies 3 on the support frame 4, the support frame 4 includes two sets of support plates 41 and two bearing seats 46 mounted on each set of support plates 41. The two sets of air knife assemblies 3 are positioned between the two sets of support plates 41, and the end tube 33 of each air knife assembly 3 passes through the bearing seats 46 of the two support plates 41 respectively. Simultaneously, the bearing seats 46 are slidably mounted on the support plates 41. Under the action of the bearing seats 46, the air knife assembly 3 is stably supported, and the position of the air knife assembly 3 can be adjusted by the movement of the bearing seats 46, providing support for timely control of the zinc layer thickness.

[0042] like Figure 7 , Figure 8 As shown, to achieve a sliding connection between the bearing housing 46 and the support plate 41, a guide rail 411 is fixedly installed on the support plate 41 along its length, and four sliders 412 are sleeved on the guide rail 411. A threaded post 413 is vertically installed on each slider 412. When assembling the bearing housing 46 and the support plate 41, the four sliders 412 are divided into two groups of two, with the two groups of sliders 412 distributed below the two bearing housings 46. The threaded post 413 penetrates through the bearing housing 46, and a nut is threaded onto the end of the threaded post 413 that protrudes from the bearing housing 46. With the cooperation of the threaded post 413 and the nut, the bearing housing 46 can be stably installed relative to the sliders 412, thereby achieving a sliding connection between the bearing housing 46 and the support plate 41.

[0043] like Figure 6 , Figure 8 As shown, in order to control the movement of the bearing seat 46, two threaded rods 414 with opposite thread directions are connected to the side of the support plate 41. A threaded sleeve 415 is fitted on each threaded rod 414. The two threaded sleeves 415 are respectively installed on the sliders 412 below the two bearing seats 46. Therefore, the movement of the sliders 412 can be controlled when the threaded rods 414 rotate, thereby adjusting the position of the bearing seat 46.

[0044] like Figure 8 As shown, in order to control the rotation of the threaded rod 414, a transmission shaft 44 is provided between the two support plates 41. The transmission shaft 44 is connected to the power output shaft of the motor 42, and the second bevel gear 45 installed at the end of the transmission shaft 44 meshes with the first bevel gear 416 of the threaded rod 414. The motor 42 can be configured as a servo motor, stepper motor, etc.

[0045] like Figure 9As shown, a brake disc 331 can also be fitted onto the end tube 33, with multiple brake holes 332 evenly distributed along its circumference on the edge of the brake disc 331. A limit bolt 462 is threaded through the threaded hole 461 at the top of the bearing seat 46, and the end of the limit bolt 462 is inserted into a brake hole 332, so that the gas output chamber 32 of the air knife assembly 3 is stably positioned at a certain angle, so that the air knife can blow the zinc liquid through. When it is necessary to adjust the tilt angle of the gas output chamber 32, the restriction of the brake disc 331 can be released to control the rotation of the air knife assembly 3, and then the limit bolt 462 will brake it again.

[0046] like Figure 7 As shown, in order to stably connect the air knife assembly 3 to the compressor 2, two end pipes 33 located on the same support plate 41 are connected by a flexible hose 43. A solenoid valve 47 is provided at the front end of the junction of a certain end pipe 33 and the flexible hose 43, and the solenoid valve 47 is connected to the compressor 2.

[0047] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0048] The above-described embodiments are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the appended claims.

Claims

1. A device for controlling the thickness of a zinc layer of a galvanized steel coil, characterized in that, The system includes two parallel air knife assemblies (3) positioned above the galvanizing tank. The air knife holes (38) of the air knife assemblies (3) are arranged adjacent to each other, and the air knife assemblies (3) are connected to a nitrogen tank (1) via a compressor (2). The two sets of air knife assemblies (3) are distributed on both sides of the steel coil and blow away the zinc liquid on the surface of the steel coil. Both ends of the two sets of air knife assemblies (3) are supported on a support frame (4). The support frame (4) is installed on the galvanizing tank and controls the relative movement of the air knife assemblies (3). An X-ray thickness gauge (5) is detachably installed on the side of one of the support frames (4). The X-ray source (51) and X-ray detector (52) of the X-ray thickness gauge (5) are used to detect the thickness of the zinc layer.

2. A device for controlling the thickness of the zinc layer of a galvanized steel coil according to claim 1, characterized in that, The air knife assembly (3) includes an outer tube (31), a gas output chamber (32) arranged along the length of the outer tube (31) and connected to the outer tube (31), and end tubes (33) respectively installed at both ends of the outer tube (31); the end of one of the end tubes (33) is closed, and the air knife hole (38) is arranged on the gas output chamber (32).

3. A device for controlling the thickness of the zinc layer of a galvanized steel coil according to claim 2, characterized in that, An inner tube (35) and a middle tube (34) are arranged sequentially from the inside to the outside of the outer tube (31). A set of air holes (36) is provided on the side wall of both the inner tube (35) and the middle tube (34). The two sets of air holes (36) are arranged far apart, and the air holes (36) of the inner tube (35) are located near the gas output chamber (32).

4. A device for controlling the thickness of the zinc layer of a galvanized steel coil according to claim 3, characterized in that, The gas output from the end pipe (33) enters the inner pipe (35) and then exits through the vent (36) to fill the middle pipe (34). The gas output from the middle pipe (34) through the vent (36) fills the outer pipe (31).

5. A device for controlling the thickness of a zinc layer of a galvanized steel coil according to claim 2, characterized in that, The gas output chamber (32) has an air cavity (37) on its inner side. The air knife hole (38) is located at the edge of the air cavity (37) away from the outer tube (31), and the size of the end of the air cavity (37) near the outer tube (31) is larger than the size of the other end.

6. The zinc coating thickness control device for galvanized steel coils according to claim 1, characterized in that, The support frame (4) includes two sets of support plates (41) and two bearing seats (46) installed on each set of support plates (41). Two sets of air knife assemblies (3) are arranged between the two sets of support plates (41), and the end tube (33) of each set of air knife assembly (3) passes through the bearing seat (46). At the same time, the bearing seat (46) is slidably arranged on the support plate (41).

7. A device for controlling the thickness of the zinc layer of a galvanized steel coil according to claim 6, characterized in that, A guide rail (411) is fixedly installed on the support plate (41) along its length direction, and four sliders (412) are sleeved on the guide rail (411). A threaded post (413) is vertically installed on each slider (412). The four sliders (412) are evenly arranged below the two bearing seats (46), and the threaded post (413) is arranged through the bearing seat (46).

8. A device for controlling the thickness of the zinc layer of a galvanized steel coil according to claim 7, characterized in that, Two threaded rods (414) with opposite thread directions are connected to the side of the support plate (41). A threaded sleeve (415) is fitted on each threaded rod (414). The two threaded sleeves (415) are respectively installed on the sliders (412) below the two bearing seats (46). A transmission shaft (44) is provided between the two support plates (41). The transmission shaft (44) is connected to the power output shaft of the motor (42). The second bevel gear (45) installed at the end of the transmission shaft (44) meshes with the first bevel gear (416) of the threaded rod (414).

9. A device for controlling the thickness of a zinc layer of a galvanized steel coil according to claim 6, characterized in that, Two end pipes (33) located on the same support plate (41) are connected by a flexible hose (43). A solenoid valve (47) is provided at the front end of the junction of one of the end pipes (33) and the flexible hose (43), and the solenoid valve (47) is connected to the compressor (2).

10. A device for controlling the thickness of a zinc layer of a galvanized steel coil according to claim 6, characterized in that, A brake disc (331) is fitted on the end tube (33), and multiple brake holes (332) are evenly distributed along the circumferential direction on the edge of the brake disc (331); a limit bolt (462) is threaded through the threaded hole (461) at the top of the bearing seat (46), and the end of the limit bolt (462) is inserted into a brake hole (332).

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