Passivation device for galvanized hot-rolled ribbed steel bars

Abstract

The passivating device comprises a passivating cylinder with two open ends and an outer cylinder surrounding the outer portion of the passivating cylinder and sealed with the outer wall of the passivating cylinder, the two ends of the passivating cylinder are arranged outside the outer cylinder, and a plurality of through holes are evenly formed in a cylinder body, located in the outer cylinder, of the passivating cylinder. A plurality of upper passivation solution inlets are formed in the top of the outer cylinder, a plurality of lower passivation solution inlets are formed in the bottom of the outer cylinder, and the upper passivation solution inlets and the lower passivation solution inlets are communicated with a passivation solution header pipe through pipelines; the passivation device further comprises a backflow system. According to the utility model, the on-line passivation of the galvanized ribbed steel bars in the conveying process is realized, and the problem that the galvanized ribbed steel bars of more than ten meters are difficult to passivate is effectively solved; according to the passivating device, the passivating barrel and the outer barrel are combined, a stable passivating liquid level is formed in the passivating barrel, when the galvanized ribbed steel bar penetrates through the passivating barrel, it is guaranteed that all parts of the galvanized ribbed steel bar can be immersed into the passivating liquid level, and the problem of leakage points is effectively solved.

Description

Technical Field

[0001] The utility model relates to the technical field of ribbed steel bars, in particular to a passivation device for galvanized hot-rolled ribbed steel bars. Background Art

[0002] Hot-rolled ribbed steel bars, commonly known as threaded steel bars, have high strength, high toughness, and good seismic resistance. They are ideal products for high-rise buildings and are widely used in the field of building concrete. In order to increase the corrosion resistance of steel bars and improve the strength and life of reinforced concrete, hot-dip galvanizing is usually performed on the outside of hot-rolled ribbed steel bars. After hot-dip galvanizing, the surface of the steel bar is covered with a pure zinc layer in the form of complete physical protection. A Zn-Fe alloy layer is also formed between the pure zinc layer and the steel bar matrix, which isolates the steel bar matrix from the atmosphere, thereby protecting the steel bar matrix from corrosion.

[0003] After galvanizing, since zinc is a very active metal, the surface of zinc will further react chemically and corrode when it comes into contact with the surrounding humid air. Therefore, the galvanized ribbed steel bars need to be passivated to prevent the galvanized workpieces from getting damp during storage and transportation, which will cause the surface of the galvanized layer to rust and discolor (white rust). The existing passivation method usually immerses the galvanized parts in the passivation solution to form a dense film composed of insoluble salt compounds on the surface of the coating, isolating the galvanized layer from the external corrosive environment to improve the corrosion resistance of the galvanized layer.

[0004] For galvanized ribbed steel bars, due to the protruding transverse ribs on the surface, the part near the bottom often leaks due to uneven immersion during passivation, which in turn affects the performance of the galvanized ribbed steel bars. In addition, the existing passivation method is only suitable for the passivation of shorter galvanized steel bars, and cannot be used for long steel bars over ten meters in length. Therefore, how to solve the above problems and improve the passivation effect has become an important issue affecting the final quality of galvanized hot-rolled ribbed steel bars. Utility Model Content

[0005] The utility model provides a passivation device for galvanized hot-rolled ribbed steel bars in order to overcome the disadvantages of the prior art.

[0006] The technical solution adopted by the utility model to solve its technical problems is:

[0007] A passivation device for galvanized hot-rolled ribbed steel bars, comprising a passivation cylinder with openings at both ends, and an outer cylinder surrounding the outside of the passivation cylinder and sealed with the outer wall of the passivation cylinder, the two ends of the passivation cylinder are arranged outside the outer cylinder, and a cylinder body of the passivation cylinder located inside the outer cylinder is evenly provided with a plurality of through holes; a plurality of upper inlets for passivation liquid are arranged at the top of the outer cylinder, and a plurality of lower inlets for passivation liquid are arranged at the bottom of the outer cylinder, and the upper inlets for passivation liquid and the lower inlets for passivation liquid are both connected to a main pipe for passivation liquid through pipelines; the passivation device also includes a reflux system for realizing the circulation of the passivation liquid.

[0008] A further improvement of the utility model is that the upper inlet of the passivation liquid and the lower inlet of the passivation liquid are arranged alternately.

[0009] A further improvement of the utility model is that the upper inlet of the passivation liquid is connected to the passivation liquid main pipe through the upper branch pipe of the passivation liquid, the lower inlet of the passivation liquid is connected to the passivation liquid main pipe through the lower branch pipe of the passivation liquid, and a secondary pressure pump is provided on the lower branch pipe of the passivation liquid.

[0010] A further improvement of the utility model is that the reflux system comprises a recovery tank, a passivation liquid tank and a circulation pump.

[0011] A further improvement of the utility model is that: a recovery tank is arranged below the inlet end and the outlet end of the passivation cylinder, the two recovery tanks are arranged in parallel and are both connected to the circulating passivation liquid tank; the outlet of the circulating passivation liquid tank and the passivation liquid main pipe are connected through a reflux pipe, and a circulation pump is arranged on the reflux pipe.

[0012] A further improvement of the utility model is that: the reflux system also includes a liquid distribution tank for replenishing the passivation liquid into the passivation liquid tank, and a stirring mechanism is installed in the liquid distribution tank.

[0013] The beneficial effects of the utility model are:

[0014] The utility model provides a passivation device for galvanized hot-rolled ribbed steel bars. The passivation cylinder structure with openings at both ends is adopted to realize the online passivation of the galvanized ribbed steel bars during the transportation process, and effectively solves the problem of the difficulty in passivating the galvanized ribbed steel bars over ten meters. The utility model introduces a large flow of passivation liquid into the outer cylinder by combining the passivation cylinder and the outer cylinder. The passivation liquid is evenly distributed after passing through the through holes on the inner wall of the passivation cylinder, and a relatively stable passivation liquid surface is formed in the passivation cylinder. When the galvanized ribbed steel bars pass through, it is ensured that all parts thereof can be immersed in the passivation liquid surface to realize surface passivation film formation, and effectively solves the leakage point problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the structure of the passivation cylinder of the utility model;

[0016] Figure 2 It is a schematic diagram of the overall structure of the utility model;

[0017] In the figure: 1. galvanized ribbed steel bars, 2-1. passivation cylinder, 2-2. outer cylinder, 2-3. through hole, 2-4. upper branch pipe of passivation liquid, 2-5. lower branch pipe of passivation liquid, 2-6. main pipe of passivation liquid, 2-7. circulating passivation liquid tank, 2-8. recovery tank, 2-9. reflux pipe, 2-10. circulation pump, 2-11. filter, 2-12. secondary pressure pump, 2-13. liquid distribution tank, 2-14. feeding pump. DETAILED DESCRIPTION

[0018] The utility model will be further described below in conjunction with the accompanying drawings.

[0019] A passivation device for galvanized hot-rolled ribbed steel bars, such as Figure 1 , Figure 2 As shown, it includes a passivation cylinder 2-1 and an outer cylinder 2-2 surrounding the outside of the passivation cylinder 2-1. The two ends of the passivation cylinder 2-1 extend out of the outer cylinder 2-2, and the two ends of the passivation cylinder 2-1 are open, and the galvanized hot-rolled ribbed steel bars pass through the passivation cylinder 2-1. The cylinder body of the passivation cylinder 2-1 located inside the outer cylinder 2-2 is evenly provided with a plurality of through holes 2-3, and the diameter of the through holes is 2mm to 3mm. A plurality of passivation liquid inlets are connected to the side wall of the outer cylinder 2-2. Specifically, a plurality of upper passivation liquid inlets are provided at the top of the outer cylinder 2-2, and a plurality of lower passivation liquid inlets are provided at the bottom of the outer cylinder 2-2. The upper passivation liquid inlets and the lower passivation liquid inlets are arranged alternately to avoid the collision of liquid flows and cause the liquid level in the passivation cylinder 2-1 to be unstable. The passivation liquid flows into the outer cylinder 2-2 through the upper inlet and the lower inlet of the passivation liquid, respectively, and enters the passivation cylinder 2-1 through the through hole 2-3 to form a stable passivation liquid surface. When the plated hot-rolled ribbed steel bar passes through the passivation cylinder 2-1 horizontally, it contacts the passivation liquid from both the upper and lower directions and forms a film passivation.

[0020] Specifically, the upper inlet of the passivation liquid is connected to the main passivation liquid pipe 2-6 through the upper branch pipe 2-4 of the passivation liquid, and the lower inlet of the passivation liquid is connected to the main passivation liquid pipe 2-6 through the lower branch pipe 2-5 of the passivation liquid, and a secondary pressure pump 2-12 is arranged on the lower branch pipe 2-5 of the passivation liquid. Although the types of the passivation liquids introduced into the upper inlet of the passivation liquid and the lower inlet of the passivation liquid are the same, the pressure of the passivation liquid introduced from the bottom of the cylinder is greater than the pressure of the passivation liquid introduced from the top of the cylinder, so that while resisting the gravity, it can give a sufficiently large upward force through the through hole 2-3, forming a stable, upwardly arched passivation liquid surface at the bottom of the passivation cylinder 2-1, even if the galvanized ribbed steel bar 1 enters close to the bottom of the passivation cylinder 2-1, it will be properly lifted up by the upward liquid flow, ensuring that the bottom of the galvanized ribbed steel bar 1 contacts the passivation liquid and forms a film. Generally speaking, the pressure of the passivation liquid is controlled at 0.1MPa~0.2MPa, and the pressure difference between the upper and lower passivation liquids is controlled at 0.05MPa~0.1MPa.

[0021] Preferably, the passivation liquid lower branch pipe 2-5 penetrates the side wall of the outer cylinder 2-2 and continues to extend until it is close to the passivation cylinder 2-1. The distance between the passivation liquid lower branch pipe 2-5 and the outer wall of the passivation cylinder 2-1 is not greater than 50mm to ensure that the liquid flow entering the passivation cylinder 2-1 has a certain impact force but does not cause splashing due to the impact force of the liquid flow.

[0022] The passivation device also includes a reflux system for realizing the circulation of the passivation liquid. Figure 2 As shown, the reflux system includes a recovery tank 2-8, a circulating passivation liquid tank 2-7 and a circulating pump 2-10.

[0023] A recovery tank 2-8 is provided below the inlet and outlet ends of the passivation cylinder 2-1. The two recovery tanks 2-8 are provided in parallel and are connected to the circulating passivation liquid tank 2-7. After the passivation liquid continuously flows into the passivation cylinder 2-1 from the outer cylinder 2-2 at a large flow rate, it flows out from the openings on both sides of the passivation cylinder 2-1, is collected by the recovery tank 2-8, and is transferred to the circulating passivation liquid tank 2-7 for repeated use.

[0024] The outlet of the circulating passivation liquid tank 2-7 is connected to the passivation liquid main pipe 2-6 through a reflux pipe 2-9, on which a circulating pump 2-10 is arranged. The passivation liquid is driven by the circulating pump 2-10 to reflux, and is directly sent to the upper branch pipe 2-4 of the passivation liquid and returned to the passivation cylinder 2-1; the passivation liquid main pipe 2-6 is also connected to the bottom of the outer cylinder through a branch pipe, on which a secondary pressure pump 2-12 is arranged, and the passivation liquid is first pressurized by the secondary pressure pump 2-12, and then returned to the passivation cylinder 2-1 through the lower branch pipe 2-5 of the passivation liquid.

[0025] A filter 2-11 is also installed on the reflux pipe 2-9 to remove impurities in the passivation solution.

[0026] The inlet end of the circulating passivation liquid tank 2-7 is also connected to the outlet end of the liquid preparation tank 2-13, and a stirring mechanism is installed on the liquid preparation tank 2-13; the raw materials of the passivation liquid and tap water are put into the liquid preparation tank 2-13 after being weighed, and after being stirred and dissolved evenly by the stirring mechanism, they are pumped into the circulating passivation liquid tank 2-7 through the feeding pump 2-14.

[0027] Since the ribbed steel bars after hot rolling are arranged side by side and transported forward synchronously, in order to restrain and smooth the ribbed steel bars horizontally, so that they can be transported smoothly and continuously and avoid steel piling, the inlet end of the passivation cylinder 2-1 is set to be a trumpet shape with a large front and a small back, which is used to restrain and feed the multiple ribbed steel bars horizontally into the box and transport them continuously.

[0028] The specific type of passivation liquid can be selected according to the requirements of downstream customers and environmental protection requirements. In the present utility model, the passivation liquid is a chromium-free passivation liquid.

[0029] The working process of the utility model is:

[0030] The galvanized hot-rolled ribbed steel bars are fed into the passivation cylinder. A large flow of passivation liquid flows into the passivation cylinder from the top of the outer cylinder, and at the same time, the passivation liquid flows into the passivation cylinder from the bottom of the outer cylinder. Under the combined effect of gravity and pressure, a higher liquid level of passivation liquid is formed in the passivation cylinder. When the galvanized hot-rolled ribbed steel bars pass through the passivation cylinder, their surfaces are fully immersed in the passivation liquid, completing full passivation film formation.

[0031] The passivation liquid flows into the circulating passivation liquid tank through the recovery tank, and is pumped back to the passivation cylinder for recycling after filtering; when the passivation liquid is insufficient, high-concentration passivation liquid is prepared through the liquid mixing tank and then pumped into the circulating passivation liquid tank for replenishment.

[0032] The embodiments described above are merely descriptions of preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A passivation device for galvanized hot-rolled ribbed steel bars, characterized in that: The invention comprises a passivation cylinder (2-1) with openings at both ends, and an outer cylinder (2-2) surrounding the outside of the passivation cylinder (2-1) and sealed with the outer wall of the passivation cylinder (2-1), wherein the two ends of the passivation cylinder (2-1) are arranged outside the outer cylinder (2-2), and a plurality of through holes (2-3) are evenly distributed on the cylinder body of the passivation cylinder (2-1) located inside the outer cylinder (2-2); a plurality of upper inlets for passivation liquid are arranged at the top of the outer cylinder (2-2), and a plurality of lower inlets for passivation liquid are arranged at the bottom of the outer cylinder (2-2), and the upper inlets for passivation liquid and the lower inlets for passivation liquid are both connected to a passivation liquid main pipe (2-6) through pipelines; and the passivation device also comprises a reflux system for realizing the circulation of the passivation liquid.

2. A passivation device for galvanized hot-rolled ribbed steel bars according to claim 1, characterized in that: The upper inlet of the passivation liquid and the lower inlet of the passivation liquid are arranged alternately.

3. A passivation device for galvanized hot-rolled ribbed steel bars according to claim 2, characterized in that: The upper inlet of the passivation liquid is connected to the passivation liquid main pipe (2-6) through the upper branch pipe (2-4) of the passivation liquid, and the lower inlet of the passivation liquid is connected to the passivation liquid main pipe (2-6) through the lower branch pipe (2-5) of the passivation liquid. A secondary pressure pump (2-12) is provided on the lower branch pipe (2-5) of the passivation liquid.

4. A passivation device for galvanized hot-rolled ribbed steel bars according to claim 1, characterized in that: The reflux system comprises a recovery tank (2-8), a circulating passivation liquid tank (2-7) and a circulating pump (2-10).

5. A passivation device for galvanized hot-rolled ribbed steel bars according to claim 4, characterized in that: A recovery tank (2-8) is disposed below the inlet and outlet ends of the passivation cylinder (2-1); the two recovery tanks (2-8) are disposed in parallel and are both connected to a circulating passivation liquid tank (2-7); the outlet of the circulating passivation liquid tank (2-7) and the passivation liquid main pipe (2-6) are connected via a reflux pipe (2-9), and a circulation pump (2-10) is disposed on the reflux pipe (2-9).

6. A passivation device for galvanized hot-rolled ribbed steel bars according to claim 4, characterized in that: The reflux system also includes a liquid preparation tank (2-13) for replenishing the passivation liquid in the passivation liquid tank, and a stirring mechanism is installed in the liquid preparation tank (2-13).

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