A continuous hot-dip galvanizing equipment for hot-rolled strip steel and a hot-dip galvanizing method thereof

Abstract

The present invention relates to the technical field of hot-dip galvanizing, specifically a continuous hot-dip galvanizing device for hot-rolled strip steel and its hot-dip galvanizing method; it includes a frame, transmission rollers and a galvanizing mechanism; the transmission rollers are located on the upper and lower sides of the strip steel, and the transmission rollers make the strip steel bend and then be transmitted in a U shape; the galvanizing mechanism is located above the strip steel before and after bending respectively, and performs hot-dip galvanizing treatment on the strip steel; the continuous hot-dip galvanizing device for hot-rolled strip steel of the present invention first performs hot-dip galvanizing treatment on the upper surface of the strip steel, coats a zinc layer, then bends the strip steel backward, making the surface with the zinc layer face down and the surface without the zinc layer face up, so as to perform hot-dip galvanizing treatment on the surface without the zinc layer, and further when performing hot-dip galvanizing treatment on the upper and lower surfaces of the strip steel, the zinc liquid is supported by the strip steel, and there will be no phenomenon that the zinc liquid attached to the lower end surface of the strip steel forms raised points on the lower end surface of the strip steel due to gravity and surface tension, resulting in uneven galvanizing.

Description

Technical Field

[0001] The invention relates to the technical field of hot-dip galvanizing, in particular to a continuous hot-dip galvanizing device for hot-rolled strip steel and a hot-dip galvanizing method thereof. Background Art

[0002] Hot-dip galvanizing refers to heating and melting zinc, and then plating the molten zinc liquid on the surface of the workpiece to form a zinc coating that protects the workpiece from oxidation;

[0003] In the existing technology for galvanizing hot-rolled steel strips, the hot-rolled steel strips are generally flattened, sunk into the galvanizing pool via transfer rollers, and then removed from the galvanizing pool, and then the hot-rolled steel strips are coiled for hot-dip galvanizing. There are also methods for galvanizing by spraying, for example, the Chinese patent application number CN201810198367.7, entitled "A Hydraulic Suspension Hot-Dip Galvanizing System for Steel Strips Using Zinc Liquid," which uses a method of flattening the steel strips, spraying molten zinc liquid on the upper and lower sides of the strips, and then scraping them flat to galvanize the steel strips.

[0004] This method has the following defects:

[0005] After the zinc liquid is sprayed onto the lower side of the strip, the melted zinc liquid is affected by the surface tension of the liquid. The molecules near the surface of the liquid are obviously affected by the molecules inside the liquid, so that the surface layer of the liquid has a tendency to shrink inward, which is manifested in that the liquid surface always tends to shrink as much as possible. In addition, the interaction force between the zinc liquid and the strip, under the action of the gravity of the zinc liquid itself, the zinc liquid often takes a semi-spherical shape (that is, the liquid falls under the action of gravity, forming convex points), which causes the galvanized layer on the lower surface of the strip to form convex points, resulting in uneven galvanized layer and affecting the effect of hot-dip galvanizing.

[0006] Therefore, the present invention proposes a continuous hot-dip galvanizing device for hot-rolled strip steel and a hot-dip galvanizing method thereof, which respectively perform galvanizing on the upper part of the strip steel before and after bending to solve the above technical problems. Summary of the Invention

[0007] In order to make up for the deficiencies of the prior art, the present invention proposes a continuous hot-dip galvanizing equipment for hot-rolled steel strip and a hot-dip galvanizing method thereof. The continuous hot-dip galvanizing equipment for hot-rolled steel strip of the present invention first performs hot-dip galvanizing treatment on the upper surface of the steel strip to coat it with a zinc layer, and then bends the steel strip backward so that the surface of the steel strip coated with the zinc layer faces downward and the surface not coated with the zinc layer faces upward, thereby performing hot-dip galvanizing treatment on the surface not coated with the zinc layer. When the upper and lower surfaces of the steel strip are hot-dip galvanized, the zinc liquid is supported by the steel strip, and the zinc liquid attached to the lower end surface of the steel strip due to gravity and surface tension will not form raised points on the lower end surface of the steel strip, resulting in uneven galvanizing.

[0008] The technical solution adopted by the present invention to solve the technical problem is: a continuous hot-dip galvanizing equipment for hot-rolled strip steel, comprising:

[0009] Frame;

[0010] Transfer rollers; The transfer rollers are located on the upper and lower sides of the strip steel, and the transfer rollers make the strip steel bend and then be transferred in a U-shape.

[0011] Galvanizing mechanism; The galvanizing mechanism is located above the strip steel before and after bending respectively, and performs hot-dip galvanizing treatment on the strip steel.

[0012] Preferably, the galvanizing mechanism includes a feed hopper, a melting bin, galvanizing nozzles and a scraper; The melting bin is fixedly connected to the frame; The feed hopper is fixedly connected above the melting bin and is internally connected to the melting bin, the galvanizing nozzles are fixedly connected below the melting bin and are connected to the melting bin, and spray the melted zinc liquid in the melting bin onto the steel plate; The scraper is installed on the frame and levels and spreads the zinc liquid sprayed onto the steel plate.

[0013] Preferably, the shape of the galvanizing nozzles is U-shaped, and spray openings for spraying zinc liquid are also provided on both sides of the galvanizing nozzles.

[0014] Preferably, collection frames are fixedly connected to the lower ends of both sides of the galvanizing nozzles; The collection frames extend below the strip steel.

[0015] Preferably, fixing grooves are opened at the bottom of the collection frames; A frustum-shaped block is inserted into the fixing grooves; A long rod is fixedly connected to the top end of the frustum-shaped block.

[0016] Preferably, a mounting plate is fixedly connected to the frame; One end of the mounting plate close to the scraper is U-shaped, and a sliding block is slidably connected inside the mounting plate; A threaded rod is in threaded cooperation with the sliding block and passes through the mounting plate and the frame, and is rotatably connected to the mounting plate and the frame, and the end of the threaded rod is rotatably connected to the mounting plate; A through groove is opened at one end of the scraper close to the mounting plate; The threaded rod passes through the through groove, so that the scraper is rotatably connected to the mounting plate.

[0017] Preferably, sliding grooves are opened on two opposite surfaces of the frame; An arc-shaped block is slidably connected to the two sliding grooves together; Support rods are symmetrically threadedly connected to the ends of the frame; One end of the support rod exposes the frame, and the other end is located inside the sliding groove.

[0018] Preferably, one end of the scraper in contact with the strip steel is arc-shaped, a cleaning motor is fixedly connected to the arc-shaped end of the scraper and a moving groove is opened; The output shaft of the cleaning motor is fixedly connected to a reciprocating screw rod; A cleaning block is in threaded cooperation with the reciprocating screw rod; The cleaning block is fitted to the outer surface of the arc-shaped end of the scraper, and the cleaning block can scrape the surface of the scraper in contact with the strip steel under the drive of the cleaning motor.

[0019] [[ID=​​S1: The strip flattener flattens the coiled strip into sheets. The flattened strip is then transferred to the bottom of the galvanizing mechanism via a transfer roller. The upper surface and both sides of the strip are galvanized. The scraper then evenly spreads the zinc liquid on the strip. After the zinc liquid cools, a galvanized layer is formed on the strip.

[0021] S2: After the first hot-dip galvanizing treatment, the strip comes into contact with the arc block as it is transported by the conveyor rollers. The arc block guides the strip downward and bends it, so that the strip enters between the conveyor rollers below. Subsequently, the lower end surface that has not been hot-dip galvanized is hot-dip galvanized by the galvanizing mechanism.

[0022] S3: After the strip is bent and enters the transmission roller below, the staff twists the support rod, so that the arc block moves away from the strip under the drive of the support rod and breaks contact with the strip.

[0023] The beneficial effects of the present invention are as follows:

[0024] 1. The continuous hot-dip galvanizing equipment for hot-rolled steel strip of the present invention first performs hot-dip galvanizing treatment on the upper surface of the steel strip to coat it with a zinc layer, and then bends the steel strip backward so that the surface of the steel strip coated with the zinc layer faces downward and the surface not coated with the zinc layer faces upward, thereby performing hot-dip galvanizing treatment on the surface not coated with the zinc layer. When the upper and lower surfaces of the steel strip are hot-dip galvanized, the zinc liquid is supported by the steel strip, and the zinc liquid attached to the lower end surface of the steel strip will not form raised points on the lower end surface of the steel strip due to gravity and surface tension, resulting in uneven galvanizing.

[0025] 2. The continuous hot-dip galvanizing equipment for hot-rolled steel strip of the present invention arranges the galvanizing nozzle into a gate shape, so that the side of the steel strip can be hot-dip galvanized, thereby preventing the situation in which the side of the steel strip is rusted and corroded due to the lack of zinc coating after the steel strip is galvanized and then wound into a steel coil by a coiler; collecting frames are arranged below both sides of the galvanizing nozzle to collect the zinc liquid dripping from the side of the steel strip, and frustum blocks are arranged to facilitate the removal of zinc blocks after the zinc liquid solidifies. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be further described below with reference to the accompanying drawings.

[0027] Figure 1 It is the overall structural diagram of the present invention;

[0028] Figure 2 yes Figure 1 Partial cross-sectional view at AA in the middle;

[0029] Figure 3 yes Figure 1 Enlarged view of point B in the middle;

[0030] Figure 4 yes Figure 3Enlarged view at position C in the figure;

[0031] Figure 5 It is a partial cross-sectional view of the galvanized nozzle, collection box and frustum block in the present invention;

[0032] Figure 6 It is a partial cross-sectional view of the sliding block, mounting plate and threaded rod in the present invention;

[0033] Figure 7 It is a process flow chart of the continuous hot-dip galvanizing method for hot-rolled strip steel in the present invention;

[0034] In the figure: 1, frame; 2, transmission roller; 3, galvanizing mechanism; 31, feed hopper; 32, melting chamber; 33, galvanized nozzle; 34, scraper; 5, collection box; 51, fixing groove; 52, frustum block; 53, long rod; 6, mounting plate; 61, sliding block; 62, threaded rod; 63, through groove; 7, sliding groove; 71, arc-shaped block; 72, support rod; 8, cleaning motor; 81, moving groove; 82, reciprocating screw rod; 83, cleaning block. Specific embodiments

[0035] In order to make the technical means, creative features, achieved purposes and functions of the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments.

[0036] A continuous hot-dip galvanizing device for hot-rolled strip steel, comprising:

[0037] Frame 1;

[0038] Transmission roller 2; The transmission roller 2 is located on the upper and lower sides of the strip steel, and the transmission roller 2 makes the strip steel bend and then be transmitted in a U shape;

[0039] Galvanizing mechanism 3; The galvanizing mechanism 3 is located above the strip steel before and after bending respectively, and performs hot-dip galvanizing treatment on the strip steel;

[0040] The galvanizing mechanism 3 includes a feed hopper 31, a melting chamber 32, a galvanized nozzle 33 and a scraper 34; The melting chamber 32 is fixedly connected to the frame 1; The feed hopper 31 is fixedly connected above the melting chamber 32 and is internally connected to the melting chamber 32, the galvanized nozzle 33 is fixedly connected below the melting chamber 32 and is connected to the melting chamber 32, and sprays the molten zinc liquid in the melting chamber 32 onto the steel plate; The scraper 34 is installed on the frame 1 to scrape and level the zinc liquid sprayed onto the steel plate;

[0041] During operation, the staff places zinc blocks into the feeding hopper 31. Thus, the zinc blocks enter the melting chamber 32 through the feeding hopper 31 and are melted by the heat generated by the heating elements (heating coils) in the melting chamber 32. The hot-rolled strip after being leveled by the leveler is transported forward through the transfer rollers 2. When the strip moves to the lower part of the galvanizing mechanism 3 located above, the molten zinc in the melting chamber 32 is evenly sprayed onto the upper surface of the strip in the width direction of the strip through the galvanizing nozzles 33. Subsequently, the strip moves together with the molten zinc on its upper surface, and the scraper 34 levels the molten zinc on the upper surface of the strip. After the molten zinc cools, a galvanized layer with uniform thickness is formed. As the strip continues to move between the transfer rollers 2, the strip is bent and moves backward, being transported in a U-shaped manner. After the strip is bent, the surface of the strip after hot-dip galvanizing is located below, and the surface of the strip that has not undergone hot-dip galvanizing is located above. At this time, the galvanizing nozzles 33 of the galvanizing mechanism 3 located below spray the molten zinc onto the upper surface of the strip that has not undergone hot-dip galvanizing. Subsequently, the scraper 34 levels the molten zinc, so as to apply a galvanized layer on the upper surface of the strip after it is bent.

[0042] The continuous hot-dip galvanizing equipment for hot-rolled strips of the present invention first performs hot-dip galvanizing treatment on the upper surface of the strip to apply a zinc layer, and then bends the strip backward, making the surface of the strip with the zinc layer face downward and the surface without the zinc layer face upward. Thus, hot-dip galvanizing treatment is performed on the surface without the zinc layer again. Furthermore, when hot-dip galvanizing treatment is performed on the upper and lower surfaces of the strip, the molten zinc is supported by the strip, and there will be no phenomenon that the molten zinc attached to the lower end surface of the strip forms raised points on the lower end surface of the strip due to gravity and surface tension, resulting in uneven galvanizing.

[0043] As an implementation manner of the present invention, the shape of the galvanizing nozzle 33 is U-shaped, and spray openings for spraying molten zinc are also provided on both sides of the galvanizing nozzle 33.

[0044] Collecting frames 5 are fixedly connected to the lower ends of both sides of the galvanizing nozzle 33; the collecting frames 5 extend to the lower part of the strip.

[0045] Fixing grooves 51 are formed at the bottom of the collecting frame 5; frustum-shaped blocks 52 are inserted into the fixing grooves 51; long rods 53 are fixedly connected to the tops of the frustum-shaped blocks 52.

[0046] When the galvanizing nozzle 33 performs hot-dip galvanizing on the strip, the molten zinc sprayed out from the spray openings on both sides of the galvanizing nozzle 33 contacts the two side surfaces of the strip in the width direction. Part of it adheres to the two end surfaces of the strip in the width direction, and the remaining part falls into the collecting frame 5 under the action of gravity. The part of the frustum-shaped block 52 exposed from the fixing groove 51 is wrapped by the collecting frame 5 and gradually cools and solidifies. After the molten zinc in the collecting frame 5 solidifies, the staff can pull the frustum-shaped block 52 through the long rod 53. Thus, the frustum-shaped block 52 disengages from the fixing groove 51 and带动 the surrounding zinc blocks to disengage from the collecting frame 5 together. Then, the staff inverts the zinc block and knocks the zinc block, so that the zinc block disengages from the frustum-shaped block 52.

[0047]

[0047] On the two sides of the strip in the width direction, the upper half and the lower half are respectively named Area 1 and Area 2. The two sides of the strip are subjected to galvanizing treatment by two groups of galvanizing mechanisms 3 on the continuous hot-dip galvanizing equipment for hot-rolled strip. When undergoing the first hot-dip galvanizing treatment, although the zinc liquid sprayed onto the side of the strip will converge downward due to gravity to Area 2, the zinc liquid remaining on Area 1 is relatively thin, resulting in uneven zinc layer thickness on the side of the strip. However, when the strip is bent and hot-dip galvanizing treatment is carried out again on the side of the strip, Area 1 is below Area 2. Therefore, during the second hot-dip galvanizing treatment, most of the zinc liquid sprayed onto the side of the strip converges to Area 1 under the action of gravity, and part of it remains in Area 2, which is opposite to the situation of the first hot-dip galvanizing treatment, thus making the galvanized layer on the side of the strip more uniform;

[0048] The continuous hot-dip galvanizing equipment for hot-rolled strip of the present invention can perform hot-dip galvanizing treatment on the side of the strip by setting the galvanizing nozzle 33 in a gate shape, thereby preventing the situation that after the strip is galvanized and wound into a strip coil by a coiler, the side of the strip coil is exposed to the air and rusts and corrodes due to no zinc layer being plated; a collection box 5 is further arranged below both sides of the galvanizing nozzle 33 to collect the zinc liquid dripping from the side of the strip, and a frustum block 52 is arranged to facilitate the removal of the zinc block after the zinc liquid solidifies.

[0049] As an implementation manner of the present invention, a mounting plate 6 is fixedly connected to the frame 1; one end of the mounting plate 6 close to the scraper 34 is in a U shape, and a sliding block 61 is slidably connected inside the mounting plate 6; a threaded rod 62 is in threaded cooperation with the sliding block 61 and passes through the mounting plate 6 and the frame 1, and is rotatably connected to the mounting plate 6 and the frame 1, and the end of the threaded rod 62 is rotatably connected to the mounting plate 6; a through groove 63 is opened at one end of the scraper 34 close to the mounting plate 6; the threaded rod 62 passes through the through groove 63, so that the scraper 34 is rotatably connected to the mounting plate 6;

[0050]

[0049] Sliding grooves 7 are opened on two opposite surfaces of the frame 1; an arc-shaped block 71 is slidably connected to the two sliding grooves 7 together; support rods 72 are symmetrically and threadedly connected to the ends of the frame 1; one end of the support rod 72 exposes the frame 1, and one end is located in the sliding groove 7;

[0051] When the staff wants to adjust the distance between the scraper 34 and the strip to change the thickness of the galvanized layer, the staff first screws out the threaded rod 62, then掰动刮板34 is not a standard English expression, it should be something like "掰动刮板34 to make the scraper 34 rotate, adjust the distance between the scraper 34 and the strip, and then the staff screws the threaded rod 62 tightly. Thus, the sliding block 61 moves in the direction close to the scraper 34 under the threaded cooperation with the threaded rod 62 and contacts the scraper 34, clamping the scraper 34. Under the action of friction, the scraper 34 is fixed, thereby completing the adjustment of the position of the scraper 34;

[0052] It should be noted that there is an unclear expression "掰动刮板34" in the original text which needs to be further clarified in the source language for a more accurate translation. The above translation is based on the existing text as much as possible.After the strip coil is uncoiled, the strip is transmitted through the transmission roller 2. When the end of the strip moves to the position of the arc block 71, the staff twists the support rod 72, so that the support rod 72 causes the arc block 71 to slide toward the direction close to the strip under the action of the thread. When the end of the strip contacts the arc block 71, the end of the strip and the arc block 71 slide against each other, and the end of the strip is guided by the arc block 71 to bend, and then enters the transmission roller 2 below, thereby completing the bending of the strip; then the staff twists the support rod 72 in the opposite direction, and the arc block 71 slides away from the strip and returns to the initial position.

[0053] As an embodiment of the present invention, the end of the scraper 34 that contacts the strip is arc-shaped, and the arc-shaped end of the scraper 34 is fixedly connected to a cleaning motor 8 and has a movable groove 81; the output shaft of the cleaning motor 8 is fixedly connected to a reciprocating screw 82; the reciprocating screw 82 is threadedly engaged with a cleaning block 83; the cleaning block 83 is in contact with the outer surface of the arc-shaped end of the scraper 34, and the cleaning block 83 can scrape the surface of the scraper 34 in contact with the strip under the drive of the cleaning motor 8;

[0054] The staff controls the cleaning motor 8 to start by using a control button connected to the cleaning motor 8, so that the output shaft of the cleaning motor 8 rotates with the reciprocating screw 82, so that the cleaning block 83 moves back and forth in the moving groove 81 under the rotation of the reciprocating screw 82, and the end of the cleaning block 83 that is in contact with the scraper 34 scrapes the surface of the scraper 34 that contacts the strip, and removes the zinc blocks attached to the scraper 34, thereby preventing the zinc blocks attached to the scraper 34 from scratching the zinc coating after contacting the strip sprayed with zinc liquid, thereby affecting the effect of hot-dip galvanizing.

Claims

1. A continuous hot-dip galvanizing equipment for hot-rolled strip steel, comprising: Frame (1); characterized in that: it further includes a transmission roller (2); both opposite surfaces of the frame (1) are provided with sliding grooves (7); an arc-shaped block (71) is slidably connected to the two sliding grooves (7) together; the ends of the frame (1) are symmetrically threadedly connected with support rods (72); one end of the support rod (72) extends out of the frame (1), and one end is located in the sliding groove (7); the transmission roller (2) is located on both the upper and lower sides of the strip steel, and the strip steel contacts the arc-shaped block (71) as it is transported by the transmission roller (2), and the arc-shaped block (71) guides the strip steel downward and bends it into a "C" shape for transmission; galvanizing mechanism (3); the galvanizing mechanism (3) is located above the strip steel before and after bending respectively, and performs hot-dip galvanizing treatment on the strip steel. The galvanizing mechanism (3) includes a feed hopper (31), a melting chamber (32), a galvanizing spray head (33) and a scraper (34); the melting chamber (32) is fixedly connected to the frame (1); the feed hopper (31) is fixedly connected above the melting chamber (32) and is internally connected to the melting chamber (32), the galvanizing spray head (33) is fixedly connected below the melting chamber (32), and is connected to the melting chamber (32), spraying the melted zinc liquid in the melting chamber (32) onto the steel plate; the scraper (34) is installed on the frame (1) to scrape and level the zinc liquid sprayed onto the steel plate. Collection frames (5) are fixedly connected to the lower ends on both sides of the galvanizing spray head (33); the collection frames (5) extend below the strip steel.

2. The continuous hot-dip galvanizing equipment for hot-rolled strip steel according to claim 1, characterized in that: The shape of the galvanizing spray head (33) is U-shaped, and spray nozzles for spraying zinc liquid are also provided on both sides of the galvanizing spray head (33).

3. The continuous hot-dip galvanizing equipment for hot-rolled strip steel according to claim 1, characterized in that: Fixing grooves (51) are opened at the bottom of the collection frame (5); frustum-shaped blocks (52) are inserted into the fixing grooves (51); long rods (53) are fixedly connected to the tops of the frustum-shaped blocks (52).

4. The continuous hot-dip galvanizing equipment for hot-rolled strip steel according to claim 1, characterized in that: A mounting plate (6) is fixedly connected to the frame (1); one end of the mounting plate (6) close to the scraper (34) is "C" shaped, and a sliding block (61) is slidably connected inside the mounting plate (6); a threaded rod (62) is in threaded cooperation with the sliding block (61) and passes through the mounting plate (6) and the frame (1), and is rotatably connected to the mounting plate (6) and the frame (1), and the end of the threaded rod (62) is rotatably connected to the mounting plate (6); a through groove (63) is opened at one end of the scraper (34) close to the mounting plate (6); the threaded rod (62) passes through the through groove (63), so that the scraper (34) is rotatably connected to the mounting plate (6).

5. The continuous hot-dip galvanizing equipment for hot-rolled strip steel according to claim 1, characterized in that: One end of the scraper (34) in contact with the strip steel is arc-shaped, a cleaning motor (8) is fixedly connected to the arc-shaped end of the scraper (34) and a moving groove (81) is opened; a reciprocating screw rod (82) is fixedly connected to the output shaft of the cleaning motor (8); a cleaning block (83) is in threaded cooperation with the reciprocating screw rod (82); the cleaning block (83) fits on the outer surface of the arc-shaped end of the scraper (34), and the cleaning block (83) can scrape the surface of the scraper (34) in contact with the strip steel under the drive of the cleaning motor (8).

6. A method for continuous hot-dip galvanizing of hot-rolled steel strips, the method being applicable to the continuous hot-dip galvanizing equipment for hot-rolled steel strips according to any one of claims 1 to 5, characterized in that: The steps of the galvanizing method are as follows: S1: the strip flattening machine flattens the rolled strip into a plate, and then the flattened strip is transported to the bottom of the galvanizing mechanism (3) through the transmission roller (2), and the upper surface and both sides of the strip are galvanized. Then the scraper (34) scrapes the zinc liquid on the strip evenly, and the zinc liquid forms a galvanized layer on the strip after cooling; S2: the strip after the first hot-dip galvanizing treatment contacts the arc block (71) as it is transported by the transmission roller (2), and the arc block (71) guides the strip downward and bends it, so that the strip enters between the transmission rollers (2) below, and then the lower end surface that has not been hot-dip galvanized is hot-dip galvanized by the galvanizing mechanism (3); S3: after the strip is bent and enters the transmission roller (2) below, the staff twists the support rod (72), so that the arc block (71) moves in a direction away from the strip under the drive of the support rod (72) and breaks contact with the strip.

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