Galvanized cooling device for hot-rolled ribbed steel bar

Abstract

The utility model provides a galvanized cooling device for hot-rolled ribbed steel bars. The galvanized cooling device comprises an air cooling mechanism and a water quenching mechanism which are sequentially arranged in the conveying direction of the hot-rolled ribbed steel bars, the air cooling mechanism comprises an air cooler and an air cooler, air inlets communicated with the outlet end of the air cooler are formed in the top and the bottom of the air cooler, and a transversely-through steel bar conveying channel is formed in the air cooler; the water quenching mechanism comprises a wear-resistant guide cylinder and a sealing cover arranged outside the wear-resistant guide cylinder, the two ends of the wear-resistant guide cylinder extend out of the sealing cover, a plurality of water holes are uniformly formed in a cylinder body, located in the sealing cover, of the wear-resistant guide cylinder, and a cold water inlet communicated with a cold water main pipe is formed in the top of the sealing cover. According to the utility model, the temperature is reduced to about 160 DEG C by adopting air cooling, and then is reduced to 40-50 DEG C by adopting large-flow cold water flushing, and the cooling speed of the zinc layer on the surface of the steel bar and the organization structure of the zinc layer are effectively controlled through secondary cooling.

Description

Technical Field

[0001] The utility model relates to the technical field of ribbed steel bars, in particular to a post-galvanizing cooling device for 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 high-temperature galvanizing, timely cooling is required to solidify the zinc liquid. However, due to the protruding transverse ribs on the surface of the ribbed steel bar, it is easy to have uneven surface cooling during the cooling process of the steel bar, which affects the coating thickness of each part, and further affects the zinc layer structure and the quality of the galvanized steel bar. Therefore, how to improve the cooling problem of hot-rolled ribbed steel bars after galvanizing has become an important issue affecting the quality of galvanized hot-rolled ribbed steel bars. Utility Model Content

[0004] The utility model provides a post-galvanizing cooling device for hot-rolled ribbed steel bars in order to overcome the drawbacks of the prior art.

[0005] The technical solution adopted by the utility model to solve its technical problems is:

[0006] A post-galvanizing cooling device for hot-rolled ribbed steel bars, comprising an air cooling mechanism and a water quenching mechanism sequentially arranged along the conveying direction of the hot-rolled ribbed steel bars; the air cooling mechanism comprises a horizontally arranged air cooler and an air cooler for providing a cooling medium to the air cooler, air inlets connected to the outlet end of the air cooler are arranged at the top and bottom of the air cooler, and a steel bar conveying channel that passes through transversely is provided inside the air cooler;

[0007] The water quenching mechanism includes a wear-resistant guide cylinder and a sealing cover arranged outside the wear-resistant guide cylinder, both ends of the wear-resistant guide cylinder extend out of the sealing cover, and both ends of the wear-resistant guide cylinder are open, and the galvanized hot-rolled ribbed steel bars pass through the wear-resistant guide cylinder; the wear-resistant guide cylinder is located in the sealing cover and has a plurality of water holes evenly distributed on its cylinder body, and a cold water inlet connected to the cold water main is provided on the top of the sealing cover.

[0008] The further improvement of the utility model is that: a wear-resistant screen plate is horizontally arranged on the upper and lower parts of the air cooler, and a plurality of air holes are evenly distributed on the wear-resistant screen plate; a steel bar conveying channel is formed between the upper and lower wear-resistant screen plates.

[0009] A further improvement of the utility model is that the air holes of the wear-resistant screen plate are inclined air holes facing the conveying direction of the ribbed steel bars.

[0010] A further improvement of the utility model is that a return water groove is arranged below the inlet end and the outlet end of the wear-resistant guide cylinder, and the return water groove is connected to the circulating cold water tank.

[0011] A further improvement of the utility model is that the bottom of the sealing cover is in a funnel shape slightly inclined toward the center of the bottom plate, and the water discharge port in the center of the bottom plate of the sealing cover is connected to the slag water bucket through a slag discharge pipe.

[0012] A further improvement of the utility model is that the water outlet of the circulating cold water tank and the cold water main pipe are connected via a reflux pipe, and a circulating water pump and a cooler are sequentially arranged on the reflux pipe along the water flow direction.

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

[0014] The utility model provides a post-galvanizing cooling device for hot-rolled ribbed steel bars, which adopts a combination of air cooling and water cooling. Air cooling is first used to reduce the temperature to about 160°C, and then a large-flow cold water flushing is used to reduce the temperature to 40°C-50°C. Through secondary cooling, the cooling rate and organizational structure of the zinc layer on the surface of the steel bar are effectively controlled, thereby achieving effective control of the quality of the galvanized steel bar. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0016] Figure 2 This is a cross-sectional structural diagram of the air cooler of the utility model;

[0017] Figure 3 It is a schematic diagram of the water quenching mechanism of the utility model;

[0018] In the figure: 1-1, air cooler, 1-2, steel bar conveying channel, 1-3 air supply pipe, 1-4, wear-resistant screen plate, 1-5, air hole, 1-6, air cooler, 1-7, upper air collecting pipe, 1-8, lower air collecting pipe, 2-1, wear-resistant guide cylinder, 2-2, sealing cover, 2-3, water hole, 2-4, cold water branch pipe, 2-5, cold water main pipe, 2-6, return water tank, 2-7, circulating cold water tank, 2-8, slag discharge pipe, 2-9, slag water bucket, 2-10, circulating water pump, 2-11, cooler, 2-12, refrigeration compressor, 2-13, filter, 2-14, return pipe, 3, ribbed steel bars. DETAILED DESCRIPTION

[0019] The utility model will be further described below in conjunction with the accompanying drawings.

[0020] A post-galvanizing cooling device for hot-rolled ribbed steel bars, such as Figure 1 , Figure 2 As shown, it includes an air cooling mechanism and a water quenching mechanism arranged in sequence along the conveying direction of the hot-rolled ribbed steel bar 3. The temperature of the hot-rolled ribbed steel bar 3 after galvanizing is about 280°C, which is cooled to about 160°C by the air cooling mechanism and then cooled to below 100°C by the water quenching mechanism.

[0021] The air cooling mechanism includes an air cooler 1-1 and an air cooler 1-6. The air cooler 1-1 is a horizontally arranged cylindrical structure, and a transversely penetrating steel bar conveying passage 1-2 is provided inside the air cooler 1-1. The top and bottom of the air cooler 1-1 are provided with a plurality of air inlets along the length direction, and the air inlets are connected to the outlet end of the air cooler 1-6 through the air supply pipe 1-3. Driven by the air cooler 1-6, cold air continuously enters the air cooler 1-1 through the air inlet, and preliminarily cools the galvanized hot-rolled ribbed steel bars 3 passing through the air cooler 1-1.

[0022] like Figure 2 As shown, a wear-resistant screen plate 1-4 is horizontally arranged at the upper and lower parts of the air cooler 1-1, and the galvanized hot-rolled ribbed steel bars 3 pass through the upper and lower wear-resistant screen plates 1-4. A plurality of air holes 1-5 are evenly distributed on the wear-resistant screen plate 1-4 to facilitate the passage of cold air. The wear-resistant screen plate 1-4 is used to support multiple parallel hot-rolled ribbed steel bars 3 to prevent them from piling up when the conveying power is insufficient.

[0023] The wear-resistant screen plates 1-4 are made of wear-resistant steel having a strength greater than that of the steel bar matrix, so as to prevent the wear-resistant screen plates 1-4 from being deformed due to collision with the ribbed steel bars 3.

[0024] Preferably, the air holes 1-5 of the wear-resistant screen plate 1-4 are inclined, and the blowing direction thereof is toward the conveying direction of the ribbed steel bars 3, which can effectively prevent the ends of the ribbed steel bars 3 from accidentally being inserted into the air holes 1-5 and causing steel accumulation. Further preferably, the angle γ between the air holes 1-5 and the horizontal direction is 30° to 45°.

[0025] Preferably, several parallel air supply pipes 1-3 located at the top of the air cooler 1-1 merge into the upper air collecting pipe 1-7 and are connected to the outlet end of the air cooler 1-6, and several parallel air supply pipes 1-3 located at the bottom of the air cooler 1-1 merge into the lower air collecting pipe 1-8 and are connected to the outlet end of the air cooler 1-6.

[0026] In order to ensure the continuous delivery of air-cooled power, a spare air cooler 1-6 is usually provided. When the air cooler 1-6 has a problem and needs to be repaired, the spare air cooler 1-6 can be used as a short-term replacement.

[0027] like Figure 3The water quenching mechanism shown includes a wear-resistant guide cylinder 2-1 and a sealing cover 2-2 arranged outside the wear-resistant guide cylinder 2-1. Both ends of the wear-resistant guide cylinder 2-1 extend out of the sealing cover 2-2, and both ends of the wear-resistant guide cylinder 2-1 are open, and the galvanized hot-rolled ribbed steel bars 3 pass through the wear-resistant guide cylinder 2-1. The wear-resistant guide cylinder 2-1 is located in the sealing cover 2-2. The cylinder body is evenly provided with a plurality of water holes 2-3. The top of the sealing cover 2-2 is provided with a plurality of cold water inlets, which are connected to the cold water main pipe 2-5 through the cold water branch pipe 2-4; the cold water enters the sealing cover 2-2 through the cold water inlet, and then flows into the wear-resistant guide cylinder 2-1 along the water holes 2-3, so as to cool the galvanized hot-rolled ribbed steel bars 3 that pass through the wear-resistant guide cylinder 2-1 horizontally.

[0028] A return water tank 2-6 is provided below the inlet and outlet of the wear-resistant guide cylinder 2-1, and the return water tank 2-6 is connected to the circulating cold water tank 2-7. After a large flow of cold water flows into the wear-resistant guide cylinder 2-1 from the top of the sealing cover 2-2, it flows out from the inlet and outlet of the wear-resistant guide cylinder 2-1, is collected by the return water tank 2-6, and is transferred to the circulating cold water tank 2-7 for reuse.

[0029] The bottom of the sealing cover 2-2 is in the shape of a funnel which is slightly inclined toward the center of the bottom plate. The drain port in the center of the bottom plate of the sealing cover 2-2 is connected to the slag water bucket 2-9 through a slag discharge pipe 2-8. The zinc slag generated during the galvanizing process falls from the surface of the steel bar and sinks to the bottom under the rapid flushing of large-flow cold water, and enters the slag water bucket 2-9 through the slag discharge pipe 2-8. After further slag and water separation, the zinc slag is collected and impurities are removed, and after drying and heating, it is returned to the zinc pot, and the cold water is put into the circulating cold water tank 2-7 for recycling.

[0030] The water quenching mechanism also includes a circulating water pump 2-10 and a cooler 2-11. The water outlet of the circulating cold water tank 2-7 and the cold water main pipe 2-5 are connected through a reflux pipe 2-14. The circulating water pump 2-10 and the cooler 2-11 are arranged in sequence along the water flow direction on the reflux pipe 2-14. The circulating water refluxes under the drive of the circulating water pump 2-10 and is cooled to 30°C by the cooler 2-11. The cooler 2-11 is a shell and tube heat exchanger or a coil heat exchanger. The cooling medium used by the cooler 2-11 is a fluorine-containing refrigerant provided by the refrigeration compressor 2-12, which can achieve a rapid drop in water temperature.

[0031] In order to improve the cleanliness of the circulating water, a filter 2-13 is further provided between the circulating water pump 2-10 and the cooler 2-11.

[0032] Since the ribbed steel bars 3 after the hot rolling are arranged in parallel and transported forward synchronously, in order to restrain and smooth the ribbed steel bars 3 laterally, so that they can be transported smoothly and continuously and avoid steel piling, the inlet end of the wear-resistant guide cylinder 2-1 and the inlet end of the wear-resistant screen plate 1-4 in the air cooler 1-1 are connected to the trumpet mouth with a large front and a small rear, which is used to restrain and feed the multiple ribbed steel bars 3 laterally into the box and transport them continuously.

[0033] The working process of the utility model is:

[0034] The temperature of the hot-rolled ribbed steel bars after galvanizing is about 450℃. They first enter the air cooler and exchange heat with the low-temperature cold air provided by the air cooler. The temperature of the hot-rolled ribbed steel bars is reduced to about 160℃, and the zinc liquid on the surface of the steel bars solidifies; the hot air after heat exchange is discharged through the inlet and outlet of the air cooler.

[0035] Subsequently, the galvanized hot-rolled ribbed steel bars are fed into the wear-resistant guide trough, and a large amount of high-pressure low-temperature cold water flows from the top of the sealing cover into the wear-resistant guide trough, quickly taking away the temperature of the galvanized hot-rolled ribbed steel bars. The low-temperature cold water flows into the circulating cold water tank through the return water tank, and under the action of the circulating water pump, it is further cooled and then recycled for water quenching.

[0036] 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 post-galvanizing cooling device for hot-rolled ribbed steel bars, characterized in that: The invention comprises an air cooling mechanism and a water quenching mechanism which are sequentially arranged along the conveying direction of the hot-rolled ribbed steel bars (3); the air cooling mechanism comprises a horizontally arranged air cooler (1-1), an air cooler (1-6) for providing a cooling medium to the air cooler (1-1), air inlets which are connected to the outlet end of the air cooler (1-6) are arranged at the top and bottom of the air cooler (1-1), and a steel bar conveying passage (1-2) which is transversely connected is provided inside the air cooler (1-1); The water quenching mechanism comprises a wear-resistant guide cylinder (2-1) and a sealing cover (2-2) arranged outside the wear-resistant guide cylinder (2-1), the two ends of the wear-resistant guide cylinder (2-1) extend out of the sealing cover (2-2), and the two ends of the wear-resistant guide cylinder (2-1) are open, and the galvanized hot-rolled ribbed steel bars (3) pass through the wear-resistant guide cylinder (2-1); a plurality of water holes (2-3) are evenly distributed on the cylinder body of the wear-resistant guide cylinder (2-1) located in the sealing cover (2-2), and a cold water inlet connected to a cold water main pipe (2-5) is opened on the top of the sealing cover (2-2).

2. The post-galvanizing cooling device for hot-rolled ribbed steel bars according to claim 1, characterized in that: A wear-resistant screen plate (1-4) is horizontally arranged at the upper and lower parts of the air cooler (1-1), and a plurality of air holes (1-5) are evenly distributed on the wear-resistant screen plate (1-4); a steel bar conveying channel (1-2) is formed between the upper and lower wear-resistant screen plates (1-4).

3. A post-galvanizing cooling device for hot-rolled ribbed steel bars according to claim 2, characterized in that: The air holes (1-5) of the wear-resistant screen plate (1-4) are inclined air holes (1-5) facing the conveying direction of the ribbed steel bars (3).

4. The post-galvanizing cooling device for hot-rolled ribbed steel bars according to claim 1, characterized in that: A water return groove (2-6) is provided below the inlet end and the outlet end of the wear-resistant guide cylinder (2-1), and the water return groove (2-6) is connected to the circulating cold water tank (2-7).

5. The post-galvanizing cooling device for hot-rolled ribbed steel bars according to claim 4, characterized in that: The bottom of the sealing cover (2-2) is in a funnel shape slightly inclined toward the center of the bottom plate, and the water discharge port at the center of the bottom plate of the sealing cover (2-2) is connected to the slag water bucket (2-9) through a slag discharge pipe (2-8).

6. The post-galvanizing cooling device for hot-rolled ribbed steel bars according to claim 4, characterized in that: The water outlet of the circulating cold water tank (2-7) and the cold water main pipe (2-5) are connected via a reflux pipe (2-14), and a circulating water pump (2-10) and a cooler (2-11) are sequentially arranged on the reflux pipe (2-14) along the water flow direction.

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