Online rust removing and inhibiting device for deformed steel bars

Abstract

The utility model relates to the field of online rust removal and corrosion inhibition of deformed steel bars. An on-line rust removing and preventing device for deformed steel bars comprises a base 1 and an aerial fog blowback device installed on the base 1, the aerial fog blowback device comprises a high-pressure air pipe 6, a high-pressure water pipe 2, a mixing barrel 3 and an annular cavity 4, the annular cavity 4 is fixed to the base 1 through the mixing barrel 3, and an inner cavity body of the mixing barrel 3 is communicated with an inner cavity body of the annular cavity 4, the high-pressure air pipe 6 and the high-pressure water pipe 2. The high-pressure air pipe 6 is connected with a lower end opening of the mixing barrel 3, the high-pressure water pipe 2 is connected with the side wall of the mixing barrel 3, multiple groups of spray heads 5 are installed on an inner ring 7 of the annular cavity 4 at equal intervals, and each group of spray heads 5 comprises two nozzles which are of a symmetrical structure and face the two ends of the annular cavity 4 respectively.

Description

Technical Field

[0001] This utility model relates to the field of online rust removal and rust prevention for rebar. Background Technology

[0002] After the implementation of GB / T 1499.2-2018 standard for straight bar rebar, specific requirements were set for the macroscopic metallographic structure of the rebar. The microstructure of the finished rebar should be ferrite (pure ferrite has good plasticity and toughness) and pearlite (pearlite has properties between ferrite and cementite, with good strength and toughness). Annular tempered martensite (tempered martensite has very high strength, hardness, wear resistance, and toughness) is not allowed.

[0003] Therefore, major rebar manufacturers can only air cool or use weak water piercing after rolling (strong water piercing will produce annular tempered martensite structure, which does not meet the national standard requirements). In order to minimize the alloy composition (alloys are expensive, and as long as the national standard requirements for mechanical properties are met, there is no requirement for the alloy composition ratio, so the lower the alloy composition, the lower the cost), it is necessary to minimize the temperature of the finished product on the cooling bed after rolling without producing annular tempered martensite structure (the cooling bed temperature is to achieve controlled cooling of the finished rebar after rolling, and improve mechanical properties through heat treatment, thereby achieving the goal of reducing alloy composition). Experiments have shown that 800-850℃ (cooling bed temperature) is the optimal temperature! However, the surface of the rebar is prone to red rust in this temperature range, which affects the surface quality of the product.

[0004] During the rolling process, a protective layer of iron oxide of a certain thickness forms on the surface of steel, isolating oxygen from the steel substrate and providing a certain degree of corrosion resistance. The iron oxide scale generally consists of three layers: the innermost layer is FeO, accounting for 45%–60%, characterized by its looseness, numerous pores, and susceptibility to cracking; the middle layer is Fe3O4, accounting for 40%–50%, characterized by its high density, corrosion resistance, and also containing pores; the outermost layer is Fe2O3, accounting for approximately 5%, with the actual proportion varying depending on the steel composition and rolling process.

[0005] The oxidation reaction is as follows: 4Fe + 3O ２ =2Fe ２ O ３

[0006] Because the volume expands when ferric oxide is formed, the rust is relatively loose, and oxygen can penetrate the rust and continue to react with the iron elements inside. The corrosion gradually expands and eventually forms defects such as holes and pits on the surface of the steel. In severe cases, it will peel off layer by layer until the steel is completely corroded. Utility Model Content

[0007] The technical problem to be solved by this utility model is: how to provide an online rust removal and rust prevention device for rebar.

[0008] The technical solution adopted by this utility model is: an online rust removal and rust prevention device for rebar, including a base 1 and an air mist backflushing device installed on the base 1. The air mist backflushing device includes a high-pressure air pipe 6, a high-pressure water pipe 2, a mixing cylinder 3, and an annular cavity 4. The annular cavity 4 is fixed on the base 1 through the mixing cylinder 3. The internal cavity of the mixing cylinder 3 is connected to the internal cavity of the annular cavity 4, the high-pressure air pipe 6, and the high-pressure water pipe 2. The high-pressure air pipe 6 is connected to the lower end port of the mixing cylinder 3, and the high-pressure water pipe 2 is connected to the side wall of the mixing cylinder 3. Multiple sets of nozzles 5 are installed at equal intervals in the inner ring 7 of the annular cavity 4. Each set of nozzles 5 includes two nozzles with a symmetrical structure facing the two ends of the annular cavity 4 respectively.

[0009] The angle between the nozzle direction of each of the two nozzles and the center line of the annular cavity 4 is 30-45° or 135-150°, respectively.

[0010] It also includes a front guide 8 and a rear guide 9 with the same structure, fixed on the base 1 and symmetrically centered on the aerosol backflushing device. Each of the front guide 8 and the rear guide 9 has a through hole. The diameter of the through hole is smaller than the diameter of the inner ring 7 of the annular cavity 4 and greater than or equal to 1.5 times the diameter of the threaded steel. The center line of the annular cavity 4, the center line of the front guide 8 and the center line of the rear guide 9 coincide.

[0011] The air pressure in high-pressure air pipe 6 is 0.5-1.5 MPa, and the water pressure in high-pressure water pipe 2 is 0.3-0.6 MPa. The air pressure to water pressure ratio is 1.3-5.

[0012] The beneficial effects of this utility model are as follows: In this utility model, when the high-temperature rebar passes through the inner ring 7 of the annular cavity 4, the high-pressure air mist water blows through the rebar. In a high-oxygen environment (high-pressure air in the high-pressure air pipe), a dense oxide layer (Fe3O4) is formed. At the same time, the high-pressure air blows away the water stains that adhere to the surface of the rebar after passing through the water, reducing the occurrence of rust. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the annular cavity structure of this utility model;

[0014] Figure 2 This is a schematic diagram of the internal cavity of the mixing cylinder of this utility model;

[0015] Figure 3 This is a schematic diagram of the overall structure of this utility model;

[0016] The components include: 1. base, 2. high-pressure water pipe, 3. mixing cylinder, 4. annular cavity, 5. nozzle, 6. high-pressure air pipe, 7. inner ring, 8. front guide frame, 9. rear guide frame, and 10. connecting device. Detailed Implementation

[0017] like Figure 1-3 As shown, this utility model requires the preparation of an annular cavity 4, a base 1, a mixing cylinder 3, a front guide 8, and a rear guide 9.

[0018] First, an annular cavity 4 is prepared. The annular cavity 4 is a ring-shaped cavity. For ease of preparation, two half-cavities can be prepared and then welded together. One side of the annular cavity 4 has a circular opening for connecting the mixing cylinder 3. Multiple sets of nozzles 5 are evenly spaced on the inner ring 7 of the annular cavity 4. Each set of nozzles 5 includes two symmetrically arranged nozzles facing both ends of the annular cavity 4 (the direction from which the threaded steel bar arrives and the direction from which it arrives). In one embodiment, the nozzle facing the direction from which the threaded steel bar arrives forms a 45-degree angle with the direction of arrival, and the nozzle facing the direction from which the threaded steel bar arrives forms a 45-degree angle with both the direction of arrival and departure. The opening of each nozzle is at a 45-degree angle, ensuring that both the nozzle facing the direction of departure and the nozzle facing the direction of arrival can spray water mist onto the threaded steel bar inside the inner ring 7.

[0019] The mixing cylinder 3 is a sealed cylinder at the bottom. Its upper opening is aligned with and welded to the circular opening of the annular cavity 4. The lower part of the mixing cylinder 3 is fixed to a flat base 3 (the base has through holes for insertion and welding). A high-pressure gas pipe 6 is connected to the lower end face of the mixing cylinder 3, with a pressure of 0.5-1.5 MPa. A high-pressure water pipe 2 is connected to the side of the mixing cylinder 3. The water pressure in the high-pressure water pipe 2 is 0.3-0.6 MPa, and the gas pressure to water pressure ratio is 1.3-5.

[0020] The front guide 8 and rear guide 9, mounted on the base 1 and located on either side of the annular cavity 4, have identical structures and are symmetrical about the annular cavity 4. Each of the front guide 8 and rear guide 9 has a through hole, the diameter of which is less than the diameter of the inner ring 7 of the annular cavity 4 but greater than or equal to 1.5 times the diameter of the threaded steel. The centerline of the annular cavity 4, the centerline of the front guide 8, and the centerline of the rear guide 9 coincide. The function of the front guide 8 and rear guide 9 is to restrict the threaded steel from passing through the inner ring 7 of the annular cavity 4 to avoid collision with the nozzle. The diameter of the through hole is less than the diameter of the inner ring 7 of the annular cavity 4 but greater than or equal to 1.5 times the diameter of the threaded steel. The centerline of the annular cavity 4, the centerline of the front guide 8, and the centerline of the rear guide 9 coincide.

[0021] The connecting device 10 is a bolt or the like, and the device of this utility model is installed on the fixed frame through the connecting device 10.

[0022] During use, the water in mixing cylinder 3 is atomized under high pressure. When sprayed onto the surface of the rebar, the atomized water droplets instantly vaporize, blowing away the red rust adhering to the surface of the rebar. At the same time, the high-pressure air comes into contact with the rebar to form a dense and stable oxide layer, preventing further corrosion of the rebar and playing the role of online rust removal and rust prevention on the production line.

Claims

1. An online rust removal and rust prevention device for rebar, characterized in that: The device includes a base (1) and an aerosol backflush device mounted on the base (1). The aerosol backflush device includes a high-pressure air pipe (6), a high-pressure water pipe (2), a mixing cylinder (3), and an annular cavity (4). The annular cavity (4) is fixed on the base (1) through the mixing cylinder (3). The internal cavity of the mixing cylinder (3) is connected to the internal cavity of the annular cavity (4), the high-pressure air pipe (6), and the high-pressure water pipe (2). The high-pressure air pipe (6) is connected to the lower end port of the mixing cylinder (3), and the high-pressure water pipe (2) is connected to the side wall of the mixing cylinder (3). Multiple sets of nozzles (5) are installed at equal intervals in the inner ring (7) of the annular cavity (4). Each set of nozzles (5) includes two nozzles with a symmetrical structure facing the two ends of the annular cavity (4).

2. The online rust removal and rust inhibition device for rebar according to claim 1, characterized in that: The angle between the nozzle direction of each of the two nozzles and the center line of the annular cavity (4) is 30-45° or 135-150° respectively.

3. The online rust removal and rust inhibition device for rebar according to claim 1, characterized in that: It also includes a front guide (8) and a rear guide (9) with the same structure fixed on the base (1) with the aerosol backflushing device as the center of symmetry. The front guide (8) and the rear guide (9) each have a through hole. The diameter of the through hole is smaller than the diameter of the inner ring (7) of the annular cavity (4) and is greater than or equal to 1.5 times the diameter of the threaded steel. The center line of the annular cavity (4), the center line of the front guide (8) and the center line of the rear guide (9) coincide.

4. The online rust removal and rust inhibition device for rebar according to claim 1, characterized in that: The air pressure of the high-pressure air pipe (6) is 0.5-1.5 MPa, the water pressure of the high-pressure water pipe (2) is 0.3-0.6 MPa, and the air pressure to water pressure ratio is 1.3-5.

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