Method and device for removing phosphorus from the surface of cold-rolled steel strip

Abstract

The application discloses a kind of cold-rolled strip steel surface phosphorus removal method and device, comprising the following steps: S1, rough scale pretreatment: make iron oxide scale crack and peeling with large tension bending straightening machine;S2, strong brushing scale removal: remove loose oxide skin by reverse pressurized wire brush roller;S3, strip steel drying: remove surface moisture with high-pressure air or hot air;S4, composite pickling solution preparation;S5, chemical pickling;S6, mechanical phosphorus removal: drive phosphorus removal component to realize brushing, stirring and oscillation;S7, spray cleaning;S8, waste liquid recovery;The application is combined in a manner of pretreatment scale breaking and cleaning, chemical pickling and mechanical synergistic phosphorus removal, significantly improves the phosphorus removal efficiency and uniformity, reduces the amount of acid, reduces environmental pollution, and realizes waste liquid resource recovery, with the comprehensive advantages of high efficiency, energy saving and environmental protection.

Description

Technical Field

[0001] This invention relates to the field of dephosphorization technology for cold-rolled strip steel, specifically to a method and apparatus for dephosphorizing the surface of cold-rolled strip steel. Background Technology

[0002] During the production of cold-rolled strip steel, an iron oxide scale layer easily forms on the surface. If it is not thoroughly removed, it will be pressed into the matrix during subsequent rolling, seriously affecting surface quality and product performance. Currently, common descaling methods mainly include physical descaling and chemical descaling. Physical methods such as brushing and shot peening can remove some of the surface oxide scale, but their effect on removing firmly attached or unevenly thick scale is limited, and it is easy to leave a bottom oxide layer. Chemical methods can dissolve scale more thoroughly, but they have problems such as long processing time, large consumption of reagents, and difficult waste liquid treatment. In addition, existing technologies often simply combine physical and chemical methods without systematic process coordination and pretreatment optimization, resulting in low descaling efficiency, poor uniformity, and high energy consumption, making it difficult to meet the requirements of efficient and environmentally friendly continuous production.

[0003] A cold-rolled strip descaling device with application number CN202222460853.6 is disclosed. This utility model includes a housing, inside which are sequentially arranged a physical descaling mechanism, an acid pickling descaling tank, and a rinsing tank. The physical descaling mechanism includes a rotating removal mechanism and a reciprocating transverse removal mechanism. The rotating removal mechanism includes a brush roller, a rotating shaft, and a motor. The brush roller is fixedly sleeved on the outside of the rotating shaft. The motor is connected to the rotating shaft via a belt. The reciprocating transverse removal mechanism includes a second motor, a rotating rod, a transverse rod, and a transverse brush roller. The rotating rod is fixed to the rotating shaft, and the motor is connected to the rotating shaft via a belt. The transverse rod has a vertical groove, and a slider is rotatably connected to the right end of the rotating rod, sliding within the vertical groove. A sliding rod is provided at the right end of the transverse rod, and the transverse brush roller is fixed to the sliding rod. A limiting block is slidably sleeved on the outside of the sliding rod. Physical descaling is achieved through the rotating removal mechanism and the reciprocating transverse removal mechanism of the physical descaling mechanism, and then the strip is sent to the acid pickling descaling tank for acid pickling.

[0004] The aforementioned existing technology uses a physical descaling method that combines brush rollers and transverse brush rollers. Although this can reduce the amount of acid used, its mechanical brushing is still limited to a single motion mode. It has limited effectiveness in removing firmly attached or unevenly distributed phosphate scale. Furthermore, the device has a complex structure, making it difficult to achieve real-time synergy between chemical and mechanical processes, which affects the overall descaling efficiency and uniformity. Summary of the Invention

[0005] The purpose of this invention is to provide a method and apparatus for descaling the surface of cold-rolled strip steel to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] On the one hand, a method for descaling the surface of cold-rolled strip steel is proposed, including the following steps:

[0008] S1. Coarse descaling pretreatment: The incoming strip steel is treated with a high-tension bending straightening machine. Through severe bending deformation, cracks and local peeling of the thick iron oxide scale on the surface are caused.

[0009] S2. Powerful brushing and descaling: The strip steel passes through a high-speed rotating wire brush roller group. The brush rollers run in reverse pressure, mechanically brushing away the loosened oxide scale and impurities.

[0010] S3. Strip drying: Before entering the dephosphorization unit, the strip is dried with high-pressure air or hot air to remove the moisture on the surface of the strip and maintain the stable concentration of acid solution.

[0011] S4. Preparation of composite pickling solution: By volume percentage, mix 15%-25% hydrochloric acid, 5%-10% sulfuric acid, 1%-3% phosphoric acid, 0.5%-1.5% corrosion inhibitor, 2%-3% citric acid, 0.1%-0.3% surfactant, 0.1%-0.2% corrosion inhibitor synergist, and the balance water, stir evenly, and prepare a composite pickling solution;

[0012] S5. Chemical pickling: The composite pickling solution prepared in S4 is pumped into the descaling device. The dried cold-rolled strip steel is continuously immersed in the composite pickling solution. The iron oxide scale on its surface is dissolved by the chemical corrosion of the composite pickling solution. The treatment time is 5-15 minutes.

[0013] S6. Mechanical dephosphorization: The dephosphorization device is driven to brush the surface of the cold-rolled strip steel to dissolve the iron oxide scale, agitate the composite pickling solution, and slightly vibrate the cold-rolled strip steel to physically remove the iron oxide scale from the surface of the cold-rolled strip steel.

[0014] S7. Spray cleaning: Use hot water at a temperature of 50-70℃ to perform high-pressure spray cleaning on the strip steel that has undergone mechanical descaling. The spray pressure is 0.3-0.8 MPa. After that, it can be immersed in a secondary rinsing tank.

[0015] S8. Wastewater recovery: Collect the waste acid generated in step S5 and the cleaning wastewater generated in step S7 respectively. The waste acid can be transported to the waste acid regeneration system for recycling and treatment. The regenerated acid can be reused for pickling solution preparation. The cleaning wastewater enters the neutralization sedimentation tank. The pH is adjusted by adding alkali. After the suspended solids are separated by sedimentation, the supernatant can be partially reused for spray cleaning or discharged in compliance with standards.

[0016] Preferably, the corrosion inhibitor is composed of one or more of calcium gluconate, zinc sulfate, dodecyl glucoside, sodium tungstate, and sodium silicate.

[0017] Preferably, the surfactant is composed of one or more of sodium dodecylbenzenesulfonate, nonylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, and polyepoxysuccinic acid.

[0018] Preferably, the corrosion inhibitor is composed of one or more of thiourea, zinc dihydrogen phosphate, hexamethylenetetramine, and triethanolamine phosphonate.

[0019] Preferably, the alkali agent in step S8 is one of a calcium hydroxide emulsion and a sodium hydroxide solution with a mass concentration of 10%-20%.

[0020] On the other hand, a descaling device for the surface of cold-rolled strip steel is proposed, including a pickling tank and a descaling assembly. A controller is installed on the left side of the front end of the pickling tank, a support frame is fixed at the bottom of the pickling tank, and a cover plate is provided on the top of the pickling tank. A first guide roller and a second guide roller are respectively installed at the upper and lower ends of the pickling tank. The first guide roller and the second guide roller are symmetrically arranged from left to right. A drain pipe is rotatably installed in the middle of the lower end of the pickling tank. The left side of the drain pipe is quickly locked to the pickling tank by bolts, and a filter screen is installed inside the upper end of the drain pipe. The descaling assembly is installed inside the pickling tank.

[0021] Preferably, the dephosphorization assembly includes a fixing plate. The top front and rear sides of the fixing plate are locked to the internal threads of the pickling tank by bolts. A multi-directional component is provided at the lower middle part of the fixing plate. The lower front end of the multi-directional component is connected to the output end of a motor. The motor is installed on the outside of the front side of the pickling tank. A brush plate assembly is connected to the bottom of the multi-directional component. The multi-directional component is connected to the upper end of a pulley assembly via a shaft. The pulley assembly is installed on the outside of the rear side of the pickling tank. A cleaning roller is connected to one side of the lower end of the pulley assembly, and the cleaning roller is built into the lower end of the pickling tank. An oscillation assembly is connected to the front end of the other side of the lower end of the pulley assembly, and the oscillation assembly is connected to the rear wall of the pickling tank.

[0022] Preferably, the multi-directional component includes a first support plate, which is locked to the outside of a fixed plate. A rotating arm is rotatably mounted on the lower end of the first support plate, and one side of the rotating arm is connected to the output end of a motor. A slider is rotatably connected to the other side of the rotating arm. The rear side of the slider is embedded inside a movable plate. The bottom of the movable plate is connected to a brush plate assembly, and a connecting block is welded to the rear side of the movable plate. The rear side of the connecting block is connected to a rack. A gear meshes with one side of the bottom of the rack, and the rack is slidably embedded inside a guide bar. The gear is rotatably mounted on the front side of the lower end of a second support plate, and the front side of the second support plate is connected to the rear side of the guide bar. The upper end of the second support plate is locked to the fixed plate, and the front side of the upper end of the second support plate abuts against the first support plate.

[0023] Preferably, the brush plate assembly includes a first connecting plate, which is bolted to the bottom of a movable plate. Connecting rods are fixed on both sides of the lower end of the first connecting plate, and the connecting rods on both sides are vertically inserted into the upper end of the second connecting plate. Springs are installed on the outside of the connecting rods on both sides, and the upper ends of the springs on both sides abut against the inside of the upper end of the second connecting plate. The second connecting plate is embedded in the lower end of the first connecting plate, and a brush plate body is quickly installed at the bottom of the first connecting plate. Transmission rods are locked on both sides of the upper end of the second connecting plate. The end of the transmission rod away from the second connecting plate is inserted into the inside of a horizontal plate. A guide groove is opened inside the horizontal plate, and the inside of the guide groove is connected to the insertion end of the transmission rod. A locking plate is fixed to the outside of the horizontal plate, and the top of the locking plate is connected to the fixed plate.

[0024] Preferably, the oscillation assembly includes a panel embedded in the rear wall of the pickling tank. A transmission arm is rotatably mounted on the right side of the panel, and the rear side of the transmission arm is opposite to the other side of the lower end of the pulley assembly. A push-pull frame is connected to the right front end of the transmission arm. A limit block is fixed to the rear of one side of the push-pull frame. A telescopic frame is connected to the left side of the push-pull frame. The right side of the telescopic frame is rotatably connected to a fixed shaft, and a roller is connected to the rear of one end of the telescopic frame. The limit block, fixed shaft, and roller all extend into the guide groove plate, and the guide groove plate is installed inside the panel. A top frame is locked to the front of the telescopic frame.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] 1. This invention uses coarse descaling pretreatment, strong brushing to remove scale, and strip drying. Before entering the descaling device, the strip is dried with high-pressure air or hot air to remove surface moisture and maintain stable acid concentration. Before entering the chemical pickling, most of the iron oxide scale and impurities on the surface are effectively broken and removed, significantly reducing the subsequent pickling load, improving the acid action efficiency and reaction uniformity. At the same time, the drying treatment maintains stable acid concentration, reducing acid consumption and process fluctuations from the source.

[0027] 2. This invention utilizes a composite pickling solution containing hydrochloric acid, sulfuric acid, phosphoric acid, corrosion inhibitors, citric acid, surfactants, and corrosion synergists. During the chemical pickling stage, it efficiently dissolves iron oxide scale, while the corrosion inhibition system effectively protects the base metal and reduces over-corrosion. Subsequently, the descaling components are activated in the pickling tank, simultaneously implementing mechanical brushing, acid agitation, and strip oscillation. This achieves a synergistic enhancement of chemical dissolution and physical stripping, significantly improving descaling efficiency and surface cleanliness uniformity. High-pressure hot water spraying and two-stage rinsing are then employed to ensure no residue remains on the surface. Furthermore, a waste acid regeneration and wastewater neutralization treatment system is integrated to achieve acid recycling and wastewater reuse or discharge that meets standards, significantly reducing treatment costs and environmental impact.

[0028] 3. This invention, by setting up multi-directional components, namely, a motor-driven rotating arm that rotates in a circle, and a slider at one end of the rotating arm that engages with a vertical groove in the moving plate, converts the rotation into horizontal reciprocating linear motion of the moving plate. At the same time, the connecting block at the rear of the moving plate drives the rack to move within the guide bar. The rack meshes with the gear, thereby intermittently converting the horizontal motion of the moving plate into forward and reverse rotation output of the gear, providing power for the subsequent belt pulley transmission, and converting a single rotational input into two output forms: horizontal reciprocating and intermittent rotation.

[0029] 4. This invention utilizes a brush plate assembly. The horizontal movement of the movable plate drives the first connecting plate fixed to it to move left and right, completing the basic brushing motion of the brush plate body. Simultaneously, the end of the transmission rod fixed on the second connecting plate is embedded in the curved guide groove of the upper horizontal plate. When the first connecting plate moves horizontally, the transmission rod moves along the guide groove trajectory, forcing the second connecting plate to reciprocate up and down along the connecting rod. This causes the brush plate body to generate intermittent downward pressure while brushing horizontally. The spring sleeved on the outside of the connecting rod provides a rebound force, ensuring that the brush plate can be reset in time after being pressed down and maintain appropriate contact pressure. In this way, it effectively removes iron oxide scale softened or loosened by acid, improving cleaning efficiency.

[0030] 5. This invention, by setting up an oscillation component, transmits the intermittent forward and reverse rotation of the gears in the multi-directional component to the pulley group through the shaft. The pulley group then distributes the power to the transmission arm of the oscillation component. The transmission arm drives the push-pull frame to reciprocate, and the push-pull frame in turn pushes the telescopic frame. The roller at one end of the telescopic frame rolls in a guide groove plate of a specific shape. Constrained by the groove trajectory, the telescopic frame completes a regular extension, contraction and swinging compound motion during the reciprocating push-pull process. Finally, the top frame fixed at the front end of the telescopic frame periodically agitates the composite pickling solution and slightly touches the strip steel to enhance the flow and mixing of the composite pickling solution and promote the contact between the composite pickling solution and the surface of the strip steel. Its slight mechanical oscillation also helps to remove iron oxide scale and further enhances the dephosphorization effect. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the phosphorus removal method of the present invention;

[0032] Figure 2 This is a three-dimensional structural diagram of the phosphorus removal device of the present invention;

[0033] Figure 3 This is a frontal view of the internal structure of the phosphorus removal device of the present invention;

[0034] Figure 4 This is a three-dimensional structural diagram of the phosphorus removal component of the present invention;

[0035] Figure 5 This is a schematic diagram of the three-dimensional combined structure of the multi-directional component and the brush plate component of the present invention;

[0036] Figure 6 This is a schematic diagram of the multi-directional component disassembly structure of the present invention;

[0037] Figure 7 This is a three-dimensional structural diagram of the brush plate assembly of the present invention;

[0038] Figure 8 This is a schematic diagram of the disassembled structure of the brush plate assembly of the present invention;

[0039] Figure 9 This is a schematic diagram of the combined structure of the pulley assembly and the oscillation component of the present invention;

[0040] Figure 10 This is a three-dimensional structural diagram of the oscillation component of the present invention.

[0041] In the diagram: Pickling tank-1, Controller-2, Support frame-3, Cover plate-4, First guide roller-5, Second guide roller-6, Drain pipe-7, Filter screen-8, Descaling assembly-9, Fixing plate-91, Multi-directional assembly-92, First support plate-921, Rotating arm-922, Slider-923, Moving plate-924, Connecting block-925, Rack-gear-926, Gear-927, Guide bar-928, Second support plate-929, Motor-93, Brush plate assembly-94, First receiving plate -941, Connecting rod -942, Spring -943, Second connecting plate -944, Brush plate body -945, Transmission rod -946, Horizontal plate -947, Guide groove -948, Locking plate -949, Pulley assembly -95, Cleaning roller -96, Vibration assembly -97, Panel -971, Transmission arm -972, Push-pull frame -973, Limiting block -974, Telescopic frame -975, Fixed shaft -976, Roller -977, Guide groove plate -978, Top frame -979. Detailed Implementation

[0042] To further explain the technical solution of the present invention, a detailed description is provided below through specific embodiments.

[0043] Please see Figure 1 This invention provides a method for descaling the surface of cold-rolled strip steel, comprising the following steps:

[0044] S1. Coarse descaling pretreatment: The incoming strip steel is treated with a high-tension bending straightening machine. Through severe bending deformation, cracks and local peeling of the thick iron oxide scale on the surface are caused.

[0045] S2. Powerful brushing and descaling: The strip steel passes through a high-speed rotating wire brush roller group. The brush rollers run in reverse pressure, mechanically brushing away the loosened oxide scale and impurities.

[0046] S3. Strip drying: Before entering the dephosphorization unit, the strip is dried with high-pressure air or hot air to remove the moisture on the surface of the strip and maintain the stable concentration of acid solution.

[0047] S4. Preparation of composite pickling solution: By volume percentage, mix 15%-25% hydrochloric acid, 5%-10% sulfuric acid, 1%-3% phosphoric acid, 0.5%-1.5% corrosion inhibitor, 2%-3% citric acid, 0.1%-0.3% surfactant, 0.1%-0.2% corrosion inhibitor synergist, and the balance water, stir evenly, and prepare a composite pickling solution;

[0048] S5. Chemical pickling: The composite pickling solution prepared in S4 is pumped into the descaling device. The dried cold-rolled strip steel is continuously immersed in the composite pickling solution. The iron oxide scale on its surface is dissolved by the chemical corrosion of the composite pickling solution. The treatment time is 5-15 minutes.

[0049] S6. Mechanical dephosphorization: The dephosphorization device is driven to brush the surface of the cold-rolled strip steel to dissolve the iron oxide scale, agitate the composite pickling solution, and slightly vibrate the cold-rolled strip steel to physically remove the iron oxide scale from the surface of the cold-rolled strip steel.

[0050] S7. Spray cleaning: Use hot water at a temperature of 50-70℃ to perform high-pressure spray cleaning on the strip steel that has undergone mechanical descaling. The spray pressure is 0.3-0.8 MPa. After that, it can be immersed in a secondary rinsing tank.

[0051] S8. Wastewater recovery: Collect the waste acid generated in step S5 and the cleaning wastewater generated in step S7 respectively. The waste acid can be transported to the waste acid regeneration system for recycling and treatment. The regenerated acid can be reused for pickling solution preparation. The cleaning wastewater enters the neutralization sedimentation tank. The pH is adjusted by adding alkali. After the suspended solids are separated by sedimentation, the supernatant can be partially reused for spray cleaning or discharged in compliance with standards.

[0052] The corrosion inhibitor is composed of one or more of calcium gluconate, zinc sulfate, dodecyl glucoside, sodium tungstate, and sodium silicate. Calcium gluconate and zinc sulfate work together to form a dense protective film to inhibit corrosion. Dodecyl glucoside improves the uniformity of film formation, and sodium tungstate enhances the self-healing ability. Sodium silicate fills the pores of the film layer and prolongs the protection time.

[0053] The surfactant is composed of one or more of sodium dodecylbenzenesulfonate, nonylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, and polyepoxysuccinic acid; sodium dodecylbenzenesulfonate reduces surface tension and accelerates dephosphorization; nonylphenol polyoxyethylene ether improves wettability and prevents acid mist leakage; and polyepoxysuccinic acid has both anti-scaling and corrosion-inhibiting functions.

[0054] The corrosion inhibitor is composed of one or more of thiourea, zinc dihydrogen phosphate, hexamethylenetetramine and triethanolamine phosphonate; thiourea and zinc dihydrogen phosphate form a multi-layer protective film to inhibit corrosion; hexamethylenetetramine and triethanolamine phosphonate work together to enhance the self-repairing ability of the film.

[0055] In step S8, the alkaline agent is either a calcium hydroxide emulsion or a sodium hydroxide solution with a mass concentration of 10%-20%.

[0056] Specifically, in step S1, the strip is subjected to severe deformation through high-tension bending straightening, causing cracks and localized peeling of the thick iron oxide scale on the surface, creating favorable conditions for loosening in subsequent processing. Next, in step S2, a high-speed rotating wire brush roller group performs reverse pressure brushing, effectively removing the loosened oxide scale and attached impurities, preventing them from affecting the pickling effect and acid life when entering the descaling unit. Finally, in step S3, the strip is dried with high-pressure air or hot air, effectively removing surface moisture and preventing acid dilution caused by water carried into the tank by the strip, thus maintaining the stability of the pickling concentration and ensuring reaction efficiency and process controllability. These three sequential steps significantly reduce the adhesion strength and overall load of the iron oxide scale before entering the chemical pickling process, improving the penetration and reaction uniformity of subsequent pickling, while reducing acid consumption, thereby enhancing the overall efficiency, economy, and stability of the descaling process.

[0057] Secondly, the above method, by preparing a composite pickling solution containing hydrochloric acid, sulfuric acid, phosphoric acid, corrosion inhibitor, citric acid, surfactant, and corrosion synergist, can efficiently dissolve iron oxide scale during the chemical pickling stage. The corrosion inhibition system can effectively protect the base metal and reduce over-corrosion. Subsequently, the descaling component is activated in the pickling tank, and mechanical brushing, acid agitation, and strip oscillation are implemented simultaneously, achieving synergistic enhancement of chemical dissolution and physical stripping, which greatly improves descaling efficiency and surface cleanliness uniformity. Afterward, hot water high-pressure spraying and two-stage rinsing are used to ensure that there are no residues on the surface. At the same time, a waste acid regeneration and cleaning wastewater neutralization treatment system is provided to realize the recycling of acid and the reuse or discharge of wastewater that meets the standards, which significantly reduces treatment costs and environmental impact.

[0058] Please see Figures 2-3 A descaling device for cold-rolled strip steel is proposed, comprising a pickling tank 1 and a descaling assembly 9. A controller 2 is installed on the left front end of the pickling tank 1, a support frame 3 is fixed at the bottom of the pickling tank 1, and a cover plate 4 is provided on the upper end of the pickling tank 1. A first guide roller 5 and a second guide roller 6 are respectively installed at the upper and lower ends inside the pickling tank 1. The first guide roller 5 and the second guide roller 6 are symmetrically arranged from left to right and are distributed along a trapezoidal installation trajectory. A drain pipe 7 is rotatably installed in the middle of the lower end of the pickling tank 1. The left side of the drain pipe 7 is quickly locked to the pickling tank 1 by bolts, and a filter screen 8 is installed inside the upper end of the drain pipe 7. The descaling assembly 9 is installed inside the pickling tank 1.

[0059] Please see Figure 4In this embodiment, the dephosphorization component 9 includes a fixing plate 91. The top front and rear sides of the fixing plate 91 are locked to the internal threads of the pickling tank 1 by bolts, thus satisfying the formation of a stable support structure. A multi-directional component 92 is provided at the lower middle part of the fixing plate 91. The lower front end of the multi-directional component 92 is connected to the output end of the motor 93. The motor 93 is installed on the outside of the front side of the pickling tank 1. A brush plate component 94 is connected to the bottom of the multi-directional component 92. The multi-directional component 92 is connected to the upper end of the pulley assembly 95 through a shaft. The pulley assembly 95 is installed on the outside of the rear side of the pickling tank 1. A cleaning roller 96 is connected to one side of the lower end of the pulley assembly 95, and the cleaning roller 96 is built into the lower end of the pickling tank 1. An oscillation component 97 is connected to the front end of the other side of the lower end of the pulley assembly 95, and the oscillation component 97 is connected to the rear wall of the pickling tank 1 to generate slight oscillation to promote the peeling of iron oxide scale.

[0060] The pulley assembly 95 consists of three pulleys and belts arranged in a triangular pattern. It can also be replaced with a toothed pulley assembly to ensure stable transmission and prevent slippage.

[0061] Please see Figures 5-6 In this embodiment, the multi-directional component 92 includes a first support plate 921, which is bolted to the outside of the fixed plate 91. A rotating arm 922 capable of 360° rotation is rotatably mounted on the lower end of the first support plate 921. The left front end of the rotating arm 922 is connected to the output end of the motor 93. A slider 923 is rotatably connected to the right side of the rotating arm 922. The rear side of the slider 923 is embedded in the moving plate 924, and a vertical groove is provided inside the moving plate 924. That is, when the rotating arm 922 rotates, the slider 923 slides up and down along the vertical groove and drives the moving plate 924 to move back and forth left and right, thereby converting the rotational motion into the planar motion required by the brush plate component 94. In the combined motion, the bottom of the movable plate 924 is connected to the brush plate assembly 94, and a connecting block 925 is welded to its rear side. The rear side of the connecting block 925 is connected to the rack 926. The rack 926 is slidably embedded in the guide bar 928 and guided by the guide bar 928 to maintain smooth movement. Its bottom left side is engaged with the gear 927. The gear 927 is rotatably mounted on the front side of the lower end of the second support plate 929, which can convert the linear motion of the rack into rotational motion and provide a power interface for possible additional functions. The front side of the second support plate 929 is connected to the rear side of the guide bar 928, and its upper end is locked to the fixed plate 91. The front side of its upper end abuts against the first support plate 921, which together enhances the structural stability.

[0062] Please see Figures 7-8In this embodiment, the brush plate assembly 94 includes a first receiving plate 941, which is inserted into the bottom of the movable plate 924 and locked with bolts. Connecting rods 942 are vertically fixed to the left and right sides of the lower end of the first receiving plate 941, and the connecting rods 942 are vertically inserted into corresponding holes at the upper end of the second receiving plate 944, allowing the second receiving plate 944 to slide up and down along the connecting rods 942. Springs 943 are installed on the outside of the connecting rods 942, and the upper ends of the springs 943 abut against the interior of the upper end of the second receiving plate 944. This abutment provides springback assistance for subsequent intermittent stamping. The second receiving plate 944 is embedded inside the lower end of the first receiving plate 941, and the first receiving plate 941... The bottom of plate 941 is quick-releasely mounted with a brush plate body 945. A transmission rod 946 is locked on each of the front and rear sides of the upper end of the second connecting plate 944. The other end of the transmission rod 946 is inserted into the interior of the horizontal plate 947. The horizontal plate 947 has multiple curved and interconnected guide grooves 948. The inserted end of the transmission rod 946 moves along the guide grooves 948, thereby converting the horizontal movement of the moving plate 924 into the regular up-and-down reciprocating movement of the second connecting plate 944. This causes the brush plate body 945 to produce an intermittent downward pressing action while brushing horizontally, enhancing the removal effect on the iron oxide scale on the surface of the strip steel. A locking plate 949 is fixed to the outside of the horizontal plate 947. The top of the locking plate 949 is connected to the fixed plate 91 to ensure the stability of the movement trajectory of the brush plate assembly 94.

[0063] Please see Figures 9-10 In this embodiment, the oscillation assembly 97 includes a panel 971, which is embedded in the rear wall of the pickling tank 1, serving as the mounting carrier for the oscillation assembly 97. A transmission arm 972 is rotatably mounted on the right side of the panel 971. The rear side of the transmission arm 972 is connected to a pulley on the other side of the lower end of the pulley assembly 95, receiving rotational power from the pulley assembly 95. The front right side of the transmission arm 972 is connected to a push-pull frame 973, which is inverted I-shape with frame structures on both sides for transmitting and converting motion modes. A limit block 974 is fixed to the rear of one side of the push-pull frame 973. Its left side is connected to the telescopic frame 975, which is composed of multiple connecting rods that rotate and connect in sequence to form a telescopic linkage mechanism. Its right side is rotatably connected to the panel 971 through the fixed shaft 976 to form a swing fulcrum. A roller 977 is installed at one end of the rear side for rolling in the guide groove to reduce friction. The limiting block 974, the fixed shaft 976 and the roller 977 are all located in the guide groove plate 978 set inside the panel 971. Three sets of top frames 979 are fixedly installed on the front side of the telescopic frame 975 for direct contact with the strip steel or liquid surface to transmit oscillation action.

[0064] The right frame of the push-pull frame 973 is connected to the front right side of the transmission arm 972, while the left frame of the push-pull frame 973 is connected to the front side of the telescopic frame 975. That is, when the push-pull frame 973 is driven to push and pull, it not only satisfies the pushing, unfolding or retracting of the telescopic frame 975, but also provides certain guiding support for the subsequent extension and swing of the telescopic frame 975 through the guidance of the left frame.

[0065] The guide trough plate 978 is composed of a straight section and a curved end, and the dimensions of the guide trough plate 978 are matched with the dimensions of the roller 977. Thus, under the guidance of the specific trajectory of the guide trough plate 978, the roller 977 drives the telescopic frame 975 to complete the compound motion of extension, contraction and swing. This allows the top frame 979 at the front end to not only periodically agitate the compound pickling solution in the pickling tank 1 to promote solution exchange and mass transfer, but also intermittently and slightly impact the surface of the strip steel, making it easier for the loosened iron oxide scale to fall off, thereby enhancing the overall dephosphorization effect.

[0066] The working principle of the phosphorus removal device in this embodiment is as follows:

[0067] First, a high-tension bending straightening machine is used to severely bend the incoming strip steel, causing the iron oxide scale to crack and peel off in some areas. Then, the strip steel passes through a high-speed rotating wire brush roller group, which brushes away the loosened oxide scale and surface impurities under reverse pressure. Finally, the strip steel is dried by high-pressure air or hot air to remove surface moisture, prevent subsequent acid dilution, and maintain a stable concentration during the pickling process.

[0068] A composite pickling solution is prepared by mixing hydrochloric acid, sulfuric acid, phosphoric acid, corrosion inhibitors, citric acid, surfactants, and corrosion synergists in a certain proportion. In this acid solution system, multiple acids work synergistically to accelerate the dissolution of iron oxide scale; corrosion inhibitors and synergists effectively protect the steel strip substrate and prevent over-corrosion; surfactants improve the wettability and penetration of the acid solution. After the steel strip is immersed in the pickling solution, a chemical corrosion reaction occurs within 5–15 minutes, causing the iron oxide scale to gradually soften and dissolve.

[0069] When the cold-rolled strip enters the descaling device for processing, the descaling device first receives the prepared composite pickling solution and pumps it into the pickling tank 1 through the pumping system. The cold-rolled strip is then guided by the first guide roller 5 and the second guide roller 6 along a trapezoidal trajectory, allowing it to be smoothly immersed in the composite pickling solution in the pickling tank 1. Since the first guide roller 5 and the second guide roller 6 are symmetrically arranged, the cold-rolled strip can be effectively prevented from deviating, ensuring that the cold-rolled strip travels straight in the pickling area. At the same time, the cover plate 4 plays a sealing role to prevent acid mist from overflowing and ensure a safe operating environment.

[0070] When the cold-rolled strip steel is immersed in the pickling solution, the acid components in the composite pickling solution react chemically with the iron oxide scale, causing it to gradually dissolve. At this time, the descaling component 9 is started simultaneously, performing a mechanical descaling action that combines brushing, stirring and oscillation.

[0071] The motor 93, installed on the outside of the front side of the pickling tank 1, drives the rotating arm 922 in the multi-directional assembly 92. The rotating arm 922 rotates 360° under the drive of the motor 93. On the other side, it engages with the vertical groove inside the moving plate 924 through the slider 923. When the rotating arm 922 rotates, the slider 923 slides up and down along the vertical groove and pushes the moving plate 924 to reciprocate in the horizontal direction, thereby converting the rotational motion of the motor 93 into the planar composite motion required by the brush plate assembly 94, providing the basic power for subsequent brushing and oscillation.

[0072] Because the bottom of the moving plate 924 is connected to the first connecting plate 941 in the brush assembly 94 by bolts, when it moves horizontally back and forth, it will synchronously drive the brush assembly 94 to move left and right. At the same time, the second connecting plate 944 is connected to the horizontal plate 947 fixed above by the transmission rod 946. The horizontal plate 947 has a curved and connected guide groove 948 inside. When the moving plate 924 moves horizontally, the transmission rod 946 moves along the trajectory of the guide groove 948, pushing the second connecting plate 944 to move up and down along the connecting rod 942. This causes the bottom brush body 945 to produce an intermittent downward action while brushing horizontally. The spring 943 is installed outside the connecting rod 942 to provide the second connecting plate 944 with rebound and reset assistance, ensuring that the brushing process is both continuous and impactful. In this way, the removal efficiency of dissolved iron oxide scale on the surface of cold-rolled strip steel is further enhanced.

[0073] Secondly, while the moving plate 924 moves horizontally back and forth, it drives the rack 926 to move linearly along the guide bar 928 through the connecting block 925 welded behind it. The rack 926 meshes with the gear 927, converting the linear motion into the rotational motion of the gear 927. Due to the reciprocating characteristics of the moving plate 924, the rack 926 and the gear 927 achieve intermittent meshing transmission, thereby causing the gear 927 to periodically rotate forward and backward. The intermittent forward and backward rotation of the gear 927 is transmitted through the shaft to the pulley group 95 installed on the rear side of the pickling tank 1. The pulley group 95 distributes the power to the cleaning roller 96 and the oscillation assembly 97 at the same time. The cleaning roller 96 is located at the lower end of the pickling tank 1. After receiving the power, it continues to rotate to perform auxiliary brushing cleaning on the lower surface of the cold-rolled strip steel, so that the lower surface of the cold-rolled strip steel can achieve simultaneous descaling.

[0074] When the power from the other side of the pulley assembly 95 is transmitted to the oscillation assembly 97, the push-pull frame 973 is reciprocated under the forward and reverse transmission drive of the transmission arm 972 because the front end of the transmission arm 972 is connected to the push-pull frame 973. The push-pull frame 973 works in concert with the telescopic frame 975, the fixed shaft 976, the roller 977 and the guide groove plate 978. That is, when the telescopic frame 975 is pushed and unfolded, the roller 977 rolls along the preset straight and curved trajectory in the guide groove plate 978, and drives the telescopic frame 975 to complete the composite motion of extension, contraction and swing. In this way, the top frame 979 connected to the front end of the telescopic frame 975 periodically agitates the composite pickling solution and intermittently and slightly impacts the surface of the strip steel, so that the loose iron oxide scale is peeled off faster. At the same time, the agitation enhances the fluidity and reaction efficiency of the composite pickling solution.

[0075] In summary, during the above process, the multi-directional component 92, brush plate component 94, cleaning roller 96, and oscillation component 97 work together to achieve multi-functional dephosphorization through chemical dissolution, mechanical brushing, liquid flow agitation, and surface oscillation. This not only improves the removal efficiency and uniformity of iron oxide scale but also promotes the fluidity and reaction efficiency of the composite pickling solution through mechanical motion.

[0076] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A descaling device for the surface of cold-rolled strip steel, characterized in that: The system includes a pickling tank (1) and a phosphorus removal assembly (9). A controller (2) is installed on the left front end of the pickling tank (1). A support frame (3) is fixed at the bottom of the pickling tank (1). A cover plate (4) is provided on the upper end of the pickling tank (1). A first guide roller (5) and a second guide roller (6) are respectively installed at the upper and lower ends inside the pickling tank (1). The first guide roller (5) and the second guide roller (6) are arranged symmetrically on the left and right. A drain pipe (7) is rotatably installed in the middle of the lower end of the pickling tank (1). The left side of the drain pipe (7) is locked to the pickling tank (1) by bolts. A filter screen (8) is installed inside the upper end of the drain pipe (7). The phosphorus removal assembly (9) is installed inside the pickling tank (1). The dephosphorization assembly (9) includes a fixing plate (91). The top front and rear sides of the fixing plate (91) are locked to the internal threads of the pickling tank (1) by bolts. A multi-directional assembly (92) is provided at the lower middle part of the fixing plate (91). The lower front end of the multi-directional assembly (92) is connected to the output end of the motor (93). The motor (93) is installed on the outside of the front side of the pickling tank (1). A brush assembly (94) is connected to the bottom of the multi-directional assembly (92). The multi-directional assembly (92) is connected to the upper end of the pulley group (95) through the shaft. The pulley group (95) is installed on the outside of the rear side of the pickling tank (1). A cleaning roller (96) is connected to one side of the lower end of the pulley group (95), and the cleaning roller (96) is built into the lower end of the pickling tank (1). An oscillation assembly (97) is connected to the front end of the other side of the lower end of the pulley group (95), and the oscillation assembly (97) is connected to the rear wall of the pickling tank (1). The multi-directional component (92) includes a first support plate (921), which is locked to the outside of the fixed plate (91). A rotating arm (922) is rotatably mounted on the lower end of the first support plate (921), and one side of the rotating arm (922) is connected to the output end of the motor (93). A slider (923) is rotatably connected to the other side of the rotating arm (922). The rear side of the slider (923) is embedded in the interior of a moving plate (924). The bottom of the moving plate (924) is connected to the brush plate assembly (94), and a component is welded to the rear side of the moving plate (924). A connecting block (925) is connected to a rack (926) at its rear side. A gear (927) meshes with one side of the bottom of the rack (926), and the rack (926) slides into the guide bar (928). The gear (927) is rotatably mounted on the front side of the lower end of the second support plate (929), and the front side of the second support plate (929) is connected to the rear side of the guide bar (928). The upper end of the second support plate (929) is locked to the fixing plate (91), and the front side of the upper end of the second support plate (929) abuts against the first support plate (921). The brush plate assembly (94) includes a first receiving plate (941), which is bolted to the bottom of the movable plate (924). Connecting rods (942) are fixed on both sides of the lower end of the first receiving plate (941), and the connecting rods (942) on both sides are vertically inserted into the upper end of the second receiving plate (944). Springs (943) are installed on the outside of the connecting rods (942) on both sides, and the upper ends of the springs (943) on both sides abut against the upper end of the second receiving plate (944). The second receiving plate (944) is embedded in the first receiving plate (941). Inside the lower end, a brush plate body (945) is quickly installed on the bottom of the first connecting plate (941). Both sides of the upper end of the second connecting plate (944) are locked with transmission rods (946). The end of the transmission rod (946) away from the second connecting plate (944) is inserted into the interior of the horizontal plate (947). The interior of the horizontal plate (947) is provided with a guide groove (948), and the interior of the guide groove (948) is connected to the insertion end of the transmission rod (946). A locking plate (949) is fixed to the outside of the horizontal plate (947), and the top of the locking plate (949) is connected to the fixing plate (91).

2. The descaling device for the surface of cold-rolled strip steel according to claim 1, characterized in that: The oscillation assembly (97) includes a panel (971) embedded in the rear wall of the pickling tank (1). A transmission arm (972) is rotatably mounted on the right side of the panel (971), and the rear side of the transmission arm (972) is connected to the other side of the lower end of the pulley assembly (95). A push-pull bracket (973) is connected to the right side of the front end of the transmission arm (972). A limit block (974) is fixed to the rear side of one side of the push-pull bracket (973). The telescopic frame (975) is connected to the left side. The right side of the telescopic frame (975) is rotatably connected to the fixed shaft (976). A roller (977) is connected to the rear side of one end of the telescopic frame (975). The limiting block (974), the fixed shaft (976), and the roller (977) all extend into the guide groove plate (978). The guide groove plate (978) is installed inside the insert plate (971). A top frame (979) is locked on the front side of the telescopic frame (975).

3. A method for descaling the surface of cold-rolled strip steel, using the descaling device described in any one of claims 1-2, characterized in that, Includes the following steps: S1. Coarse descaling pretreatment: The incoming strip steel is treated with a high-tension bending straightening machine. Through severe bending deformation, cracks and local peeling of the thick iron oxide scale on the surface are caused. S2. Powerful brushing and descaling: The strip steel passes through a high-speed rotating wire brush roller group. The brush rollers run in reverse pressure, mechanically brushing away the loosened oxide scale and impurities. S3. Strip drying: Before entering the dephosphorization unit, the strip is dried with high-pressure air or hot air to remove the moisture on the surface of the strip and maintain the stable concentration of acid solution. S4. Preparation of composite pickling solution: By volume percentage, mix 15%-25% hydrochloric acid, 5%-10% sulfuric acid, 1%-3% phosphoric acid, 0.5%-1.5% corrosion inhibitor, 2%-3% citric acid, 0.1%-0.3% surfactant, 0.1%-0.2% corrosion inhibitor synergist, and the balance water, stir evenly, and prepare a composite pickling solution; S5. Chemical pickling: The composite pickling solution prepared in S4 is pumped into the descaling device. The dried cold-rolled strip steel is continuously immersed in the composite pickling solution. The iron oxide scale on its surface is dissolved by the chemical corrosion of the composite pickling solution. The treatment time is 5-15 minutes. S6. Mechanical dephosphorization: The dephosphorization device is driven to brush the surface of the cold-rolled strip steel to dissolve the iron oxide scale, agitate the composite pickling solution, and slightly vibrate the cold-rolled strip steel to physically remove the iron oxide scale from the surface of the cold-rolled strip steel. S7. Spray cleaning: Use hot water at a temperature of 50-70℃ to perform high-pressure spray cleaning on the strip steel that has undergone mechanical descaling. The spray pressure is 0.3-0.8 MPa. Then, it enters the secondary rinsing tank for immersion cleaning. S8. Wastewater recovery: The waste acid generated in step S5 and the cleaning wastewater generated in step S7 are collected separately. The waste acid is transported to the waste acid regeneration system for recycling and treatment. The regenerated acid is reused for pickling solution preparation, while the cleaning wastewater enters the neutralization sedimentation tank. The pH is adjusted by adding an alkali agent. After the suspended solids are separated by sedimentation, part of the supernatant is reused for spray cleaning or discharged in compliance with standards.

4. The method for descaling the surface of cold-rolled strip steel according to claim 3, characterized in that: The corrosion inhibitor is composed of one or more of the following: calcium gluconate, zinc sulfate, dodecyl glucoside, sodium tungstate, and sodium silicate.

5. The method for descaling the surface of cold-rolled strip steel according to claim 3, characterized in that: The surfactant is composed of one or more of sodium dodecylbenzenesulfonate, nonylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, and polyepoxysuccinic acid.

6. The method for descaling the surface of cold-rolled strip steel according to claim 3, characterized in that: The corrosion inhibitor is composed of one or more of thiourea, zinc dihydrogen phosphate, hexamethylenetetramine, and triethanolamine phosphonate.

7. The method for descaling the surface of cold-rolled strip steel according to claim 3, characterized in that: The alkaline agent in step S8 is either a calcium hydroxide emulsion or a sodium hydroxide solution with a mass concentration of 10%-20%.

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