A gas mist cooling ring for hot-rolled high-strength bars

Abstract

An aerosol cooling ring for hot-rolled high-strength bars belongs to the technical field of steel rolling. It includes a mounting base, an air inlet, a water inlet, an annular air distribution box, an annular water distribution box, a mixing chamber, an aerosol outlet 1, an aerosol outlet 2, an inspection hole, a T-bolt hole, a fixing bolt, an O-type sealing gasket, and a protective plate. The nozzles of the aerosol cooling ring are installed and applied in the aerosol cooling device of the hot-rolled high-strength bar unit in a grouped and segmented manner, which effectively improves the heat exchange efficiency of the hot-rolled bars and effectively controls the cooling rate of the hot-rolled bars. While significantly improving the strength of the hot-rolled bars, it not only avoids the formation of surface martensitic rings in the cross section of the bars and the generation of surface red rust, but also can inhibit the precipitation of high-carbon steel carbides.

Description

Technical Field

[0001] The invention belongs to the technical field of steel rolling, and in particular relates to an aerosol cooling ring for hot-rolled high-strength bars, and is suitable for an annular aerosol cooling nozzle for hot-rolled bars. Background Art

[0002] In the past 20 years, my country's hot-rolled bars have been using water-through cooling and water tank cooling methods. While improving the strength, it inevitably brings martensite rings, easy red rust on the surface, and the inability to accurately control the precipitation of carbides. In order to improve the cooling efficiency of hot-rolled bars, improve the strength of bars, and improve the precipitation of network and band carbides, while effectively controlling the cooling rate and quenching martensite phase transformation, it is necessary to develop a method and device for hot-rolled bars under the conditions of final rolling temperature (800-1050℃) that has sufficient cooling capacity and cooling rate, and is convenient for accurately controlling the cooling length. The water mist cooling method is to mix water and gas (air or nitrogen), with a large amount of water, and is easy to arrange and assemble flexibly individually or in groups and sections, and has a wide cooling rate range. However, in terms of improving the cooling efficiency, the water mist nozzle has a large amount of water, and the air-water flow ratio (or simply the air-water ratio) is controlled at 30-5. In addition, most of the designed water mist cooling nozzles are single nozzles, and most of them use internal mixing chambers to achieve atomization. As a result, the pipeline is complicated and the mixing chamber design is difficult, which cannot meet actual needs.

[0003] The difference between the gas mist cooling nozzle and the water mist cooling nozzle is that the gas volume is greater than the water volume, and the gas-water flow ratio (or simply the gas-water ratio) has a wide control range and can be adjusted arbitrarily between 100 and 10. It can effectively and accurately control the cooling rate of the hot-rolled bar according to the CCT continuous cooling transformation curve characteristics of the bar and the requirements for controlling the cooling process parameters to obtain the required microstructure and mechanical properties. Summary of the invention

[0004] The purpose of the present invention is to provide an aerosol cooling ring for hot-rolled high-strength bars, which solves the problem that various existing water mist nozzles cannot meet the requirements of high-efficiency cooling function of hot-rolled high-strength bars. On this basis, the nozzles of the present invention are installed and applied in the aerosol cooling device of the hot-rolled high-strength bar unit in a grouped and segmented manner, which effectively improves the heat exchange efficiency of the hot-rolled bars and effectively controls the cooling rate of the hot-rolled bars. While significantly improving the strength of the hot-rolled bars, it not only avoids the formation of surface martensitic rings in the cross section of the bars and the generation of surface red rust, but also can inhibit the precipitation of high-carbon steel carbides.

[0005] The present invention comprises a mounting base 1, an air inlet 2, a water inlet 3, an annular air distribution box 4, an annular water distribution box 5, a mixing chamber 6, an aerosol outlet 1 7, an aerosol outlet 2 8, an inspection hole 9, a T-bolt hole 10, a fixing bolt 11, an O-type sealing gasket 12 and a protective plate 13; an air inlet 2 is provided on the upper part of the mounting base 1, and after being connected with the annular air distribution box 4, the air enters the mixing chamber 6 through the air inlet hole in the mixing chamber 6; a water inlet 3 is provided on the upper part of the mounting base 1, and after being connected with the annular water distribution box 5, the air enters the mixing chamber 6 through the water inlet hole in the mixing chamber 6, and after being evenly mixed, the air passes through the aerosol outlet 1 7 and the aerosol outlet 2 8 provided on the lower part of the mounting base 1; the aerosol is sprayed out at an angle of 90° to 30° and a pressure of 0.01 to 0.7 MPa; an inspection hole 9 is provided on the mixing chamber 6, and a protective plate 13 is provided on the outside; fixing bolts 11 and O-type sealing gaskets 12 fix the mounting base 1 to the air and water pipelines of the equipment through the T-bolt holes 10.

[0006] The aerosol cooling ring of the present invention vaporizes instantaneously in the high temperature zone (1050-700°C) of the hot-rolled bar finishing temperature when the water and gas supply conditions reach the required water pressure, water volume, gas pressure and gas volume range, and takes away a large amount of vaporization phase change latent heat, so that the hot-rolled bar can obtain high-efficiency aerosol cooling.

[0007] The nozzle of the gas mist cooling ring adopts a double superimposed nozzle section of a direct spray fan type and an oblique spray fan type (angle 90°~30°), so that the jet forms a fixed flat shape. On the one hand, the vertical direct spray fan type evenly covers the entire bar section, and on the other hand, the oblique spray fan type increases the coverage length of the fan-shaped water mist along the rolling direction of the hot bar, which can not only reduce the attenuation and escape of the jet in the air caused by the gas-water mixed atomization, but also concentrate the jet on the arc surface of the hot bar, maximize the use of the gas-water atomization jet, and make the cooling effect more uniform. In this way, the hot-rolled bar can obtain a good, stable and rapid cooling curve.

[0008] The inspection hole 9 of the aerosol cooling ring is a spiral inspection hole, which is convenient for rapid maintenance and overhaul.

[0009] The aerosol cooling ring can be used at a gas pressure of 0.1 to 0.8 MPa and a pressure of 50 to 1000 Nm. 3 Within the flow range, the area of ​​aerosol particle size distribution and the aerosol size are flexibly adjusted between 30 and 500 μm, so that the proportion of vaporization cooling in mixed cooling (including contact cooling, film boiling cooling, and vaporization cooling) can be increased to varying degrees under the initial conditions of the same final rolling temperature for hot-rolled bars, thereby obtaining different heat exchange efficiencies and cooling rates.

[0010] The impact force of the nozzle of the aerosol cooling ring is 0.8-10 kg / mm 2 It can effectively avoid the formation of red rust on the surface of the bar and the damage of iron oxide scale, and delay rust. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is the overall appearance structure diagram of the aerosol ring of the present invention.

[0012] Figure 2 It is a front view internal structure diagram of the aerosol ring of the present invention.

[0013] Figure 3 It is the left side view of the internal structure of the aerosol ring of the patent of the present invention.

[0014] Figure 4 A typical water mist particle size distribution diagram for an air mist cooling ring used for hot rolling high-strength bars.

[0015] Figure 5 It is a typical aerosol shape and size test data diagram of the aerosol cooling ring of the present invention.

[0016] Figure 6 This is a test diagram of the impact force of the patented aerosol cooling ring of the present invention.

[0017] In the figure, there are installed base 1, air inlet 2, water inlet 3, annular air distribution box 4, annular water distribution box 5, mixing chamber 6, aerosol outlet 1 7, aerosol outlet 2 8, inspection hole 9, T-bolt hole 10, fixing bolt 11, O-type sealing gasket 12, and protective plate 13. DETAILED DESCRIPTION

[0018] The present invention comprises a mounting base 1, an air inlet 2, a water inlet 3, an annular air distribution box 4, an annular water distribution box 5, a mixing chamber 6, an aerosol outlet 1 7, an aerosol outlet 2 8, an inspection hole 9, a T-bolt hole 10, a fixing bolt 11, an O-type sealing gasket 12, and a protective plate 13. In order to illustrate the specific implementation of the aerosol cooling ring for hot-rolled high-strength bars of the present invention, the following is combined with the attached Figure 1 -6.

[0019] like Figure 1 and Figure 2 As shown, an aerosol cooling ring for hot-rolled high-strength bars is mainly composed of an air inlet 2 provided on the upper part of the mounting base 1 of the aerosol cooling ring and an annular air distribution box 4 connected, and then the air enters the mixing chamber 6 through the air inlet hole in the mixing chamber 6, and the water inlet 3 provided on the upper part of the mounting base 1 is connected to the annular water distribution box 5 and then enters the mixing chamber 6 through the water inlet hole in the mixing chamber 6, and after uniform mixing, it passes through the aerosol outlet 1 7 and the aerosol outlet 2 8 provided at the lower part. There is an inspection hole 9 on the mixing chamber 6. In order to protect the inspection hole, a protective plate 13 is arranged outside, and the fixing bolts 11 and O-type sealing gaskets 12 fix the mounting base 1 to the equipment gas and water pipelines through the T-bolt holes 10.

[0020] like Figure 2As shown, the aerosol outlet 1 of the aerosol cooling ring adopts a direct spray fan type, and the aerosol outlet 2 adopts an oblique spray fan type, which is sprayed out at an angle of 60° and a pressure of 0.7MPa, which is adjusted specifically according to the process requirements. The nozzle cross-section of the direct spray fan type and the oblique spray fan type is superimposed to form a fixed flat shape of the jet. On the one hand, the vertical direct spray fan type evenly covers the entire bar section, and on the other hand, the oblique spray fan type increases the coverage length of the fan-shaped water mist along the rolling direction of the hot bar. It can not only reduce the attenuation and escape of the jet in the air caused by the gas-water mixed atomization, but also concentrate the jet on the arc surface of the hot bar, maximize the use of the gas-water atomization jet, and make the cooling effect more uniform. In addition, the hot-rolled bar obtains a good, stable and rapid cooling curve. The spiral inspection hole 9 adopted by the aerosol ring can achieve rapid maintenance and repair through a dust blowing device.

[0021] like Figure 3 As shown, the aerosol cooling ring can flexibly adjust the aerosol particle size distribution area and the aerosol size within the range of 100 to 300 μm when the water supply and gas supply conditions reach the required water pressure, water volume, air pressure and gas volume. The aerosol instantaneously vaporizes in the high temperature zone (1050 to 700°C) of the hot-rolled bar's final rolling temperature and takes away a large amount of latent heat of vaporization phase change, so that the hot-rolled bar can obtain highly efficient aerosol cooling.

[0022] like Figure 3 and Figure 4 As shown, the aerosol cooling ring can be used at a gas pressure of 0.5 to 0.7 MPa and a force of 50 to 150 Nm 3 Within the flow range, the area of ​​aerosol particle size distribution and the aerosol size are flexibly adjusted between 38 and 500 μm, so that the proportion of vaporization cooling in mixed cooling (including contact cooling, film boiling cooling, and vaporization cooling) can be increased to varying degrees under the initial conditions of the same final rolling temperature for hot-rolled bars, thereby obtaining different heat exchange efficiencies and cooling rates.

[0023] like Figure 5 As shown, the impact force of the aerosol cooling ring is 0.8~1.3kg / mm 2 It can effectively avoid the formation of red rust on the surface of the bar and the damage of iron oxide scale, and delay rust.

[0024] In summary, the present invention discloses an aerosol cooling ring for hot-rolled high-strength bars, and provides an annular aerosol cooling nozzle for hot-rolled bars. On this basis, the aerosol cooling ring of the present invention is installed and applied in the aerosol cooling device of the hot-rolled high-strength bar unit in a grouped and segmented manner, which effectively improves the heat exchange efficiency of the hot-rolled bars and effectively controls the cooling rate of the hot-rolled bars. While significantly improving the strength of the hot-rolled bars, it not only avoids the formation of surface martensitic rings in the cross section of the bars and the generation of surface red rust, but also can inhibit the precipitation of high-carbon steel carbides. At the same time, the present invention is not limited to bars, and the cooling of steel sections, plates, strips, and pipes can also refer to the present invention.

Claims

1. A gas mist cooling ring for hot-rolled high-strength bars, characterized in that: The invention comprises a mounting base (1), an air inlet (2), a water inlet (3), an annular air distribution box (4), an annular water distribution box (5), a mixing chamber (6), an aerosol outlet 1 (7), an aerosol outlet 2 (8), a maintenance hole (9), a T-shaped bolt hole (10), a fixing bolt (11), an O-shaped sealing gasket (12), and a protective plate (13); the mounting base (1) is provided with an air inlet (2) on the top, and after being connected to the annular air distribution box (4), the air enters the mixing chamber (6) through the air inlet hole in the mixing chamber (6); the mounting base (1) is provided with a water inlet ( 3), after being connected to the annular water distribution box (5), the liquid enters the mixing chamber (6) through the water inlet hole in the mixing chamber (6), and after being evenly mixed, it is ejected through the aerosol outlet 1 (7) and aerosol outlet 2 (8) provided at the lower part of the mounting base (1); at an angle of 90° to 30° and a pressure of 0.01 to 0.7 MPa; an inspection hole (9) is provided on the mixing chamber (6), a protective plate (13) is provided on the outside, and the mounting base (1) is fixed to the gas and water pipelines of the equipment through the T-bolt holes (10); The nozzle of the aerosol cooling ring adopts a nozzle cross section of a double superposition of a direct spray fan type and an oblique spray fan type, with an angle of 90° to 30°; the aerosol outlet 1 of the aerosol cooling ring adopts a direct spray fan type, and the aerosol outlet 2 adopts an oblique spray fan type; The impact force of the nozzle of the aerosol cooling ring is 0.8-10 kg / mm 2 .

2. The gas mist cooling ring for hot-rolled high-strength bars according to claim 1, characterized in that: The inspection hole (9) is a spiral inspection hole.

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