Liquid nitrogen cooling system for rolling mill

Abstract

The present invention relates to a liquid nitrogen cooling system for a rolling mill, comprising a liquid nitrogen distributor, a compressed air pipeline and a two-fluid nozzle arranged at a rolling roller, wherein the compressed air in the compressed air pipeline and the liquid nitrogen in the liquid nitrogen distributor converge in the two-fluid nozzle, and the compressed air disperses the liquid nitrogen into small liquid nitrogen droplets, which are sprayed toward the rolling roller together with the compressed air. The present invention uses compressed air to convert liquid nitrogen into small droplets and sprays them onto the surface of the rolling roller to quickly absorb heat, and the small droplets can prevent the rolling roller from cooling too fast and causing overcooling, and can prevent the droplets from falling on the plate strip, which will not affect the quality of the plate strip.

Description

Technical Field

[0001] The invention relates to the field of rolling mills, and more particularly to a liquid nitrogen cooling system for a rolling mill. Background Art

[0002] The temperature of the composite strip during the low-temperature rolling process is about 450 degrees Celsius, and the temperature of the roller surface will be very high. If the roller surface is not cooled, the roller will fail very quickly. Ordinary cooling methods such as emulsions or rolling oils cannot be used. The presence of emulsions or rolling oils will affect the composite of the strip. Currently, there is no roller cooling system for low-temperature rolling. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a liquid nitrogen cooling system for a rolling mill, which can effectively reduce the surface temperature of the rolling rolls, ensure the hardness and strength of the rolling rolls, and will not affect the composite quality of the plates and strips.

[0004] The technical solution adopted by the present invention to solve the technical problem is: construct a liquid nitrogen cooling system for a rolling mill, including a liquid nitrogen distributor, a compressed air pipeline and a two-fluid nozzle arranged at the rolling roller, the compressed air in the compressed air pipeline and the liquid nitrogen in the liquid nitrogen distributor merge in the two-fluid nozzle, the compressed air disperses the liquid nitrogen into small liquid nitrogen droplets, and the small liquid nitrogen droplets are sprayed toward the rolling roller together with the compressed air.

[0005] In the above scheme, a trumpet-shaped cover is provided on the outside of the two-fluid nozzle, a collecting groove is provided below the two-fluid nozzle, an air hole is provided on the side of the cover opposite to the collecting groove, a plurality of slits are provided above the collecting groove, the collecting groove is connected to a nitrogen exhaust pipe, and the nitrogen exhaust pipe is connected to an exhaust fan.

[0006] In the above scheme, protective baffles are provided on the operating side and the transmission side of the rolling mill, protective plates are provided at the inlet and outlet of the plate and strip, and gaps are provided on the protective plates for the plate and strip to enter and exit the rolling mill.

[0007] In the above scheme, the liquid nitrogen distributor includes a control valve and a liquid nitrogen pipe, the side of the liquid nitrogen pipe is provided with liquid nitrogen discharge holes arranged at intervals, each liquid nitrogen discharge hole is connected to a two-fluid nozzle, and the liquid nitrogen pipe is provided with an intermediate pipeline and two side pipelines arranged on both sides of the intermediate pipeline. The intermediate pipeline and the side pipeline are respectively connected to three liquid nitrogen delivery pipes, and each liquid nitrogen delivery pipe is connected to the control valve.

[0008] In the above solution, the middle pipeline and the side pipeline are separated by a partition.

[0009] In the above solution, the liquid nitrogen dispenser is connected to the liquid nitrogen storage tank via a liquid nitrogen pump.

[0010] In the above solution, the liquid nitrogen storage tank is connected to the liquid nitrogen generator.

[0011] The liquid nitrogen cooling system for a rolling mill according to the present invention has the following beneficial effects:

[0012] 1. The present invention uses compressed air to convert liquid nitrogen into small droplets and sprays them onto the surface of the roller to quickly absorb heat. The small droplets can prevent the roller from cooling too quickly and causing overcooling, and can prevent the droplets from falling on the strip, which will not affect the quality of the strip;

[0013] 2. In a nitrogen atmosphere, the strip will not oxidize even if the temperature is high;

[0014] 3. The vaporized nitrogen can be quickly discharged from the rolling mill through the collecting tank and the nitrogen exhaust pipe, and the temperature inside the rolling mill can be maintained at a higher temperature, thereby preventing the water-containing air inside the rolling mill from frosting inside the rolling mill and causing damage to the rolling mill. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0016] Figure 1 It is a structural schematic diagram of the liquid nitrogen cooling system of the rolling mill of the present invention;

[0017] Figure 2 yes Figure 1 AA section view in;

[0018] Figure 3 It is a structural schematic diagram of a liquid nitrogen dispenser;

[0019] Figure 4 yes Figure 3 Side view of. DETAILED DESCRIPTION

[0020] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0021] like Figure 1-4 As shown, the liquid nitrogen cooling system for a rolling mill of the present invention comprises a liquid nitrogen distributor 6 , a compressed air pipeline 5 and a two-fluid nozzle 4 arranged at the rolling roll 1 .

[0022] The compressed air and the liquid nitrogen in the liquid nitrogen distributor 6 converge in the two-fluid nozzle 4, and the compressed air disperses the liquid nitrogen into small liquid nitrogen droplets, which are sprayed toward the roller 1 together with the compressed air. The liquid nitrogen distributor and the two-fluid nozzle 4 can evenly distribute the liquid nitrogen on the roller surface of the roller 1. After the liquid nitrogen contacts the roller 1, it is completely vaporized, taking away the heat. The liquid nitrogen will not flow to the surface of the roller 1, and the plate strip 2 will not be cooled. A nitrogen intake port is provided near the plate strip 2, which can quickly discharge the vaporized nitrogen.

[0023] Furthermore, a trumpet-shaped cover body 3 is provided on the outside of the two-fluid nozzle 4, a collecting tank 8 is provided below the two-fluid nozzle 4, and an air hole is provided on the side of the cover body 3 opposite to the collecting tank 8. The cover body 3 can prevent nitrogen from overflowing, the inside of the collecting tank 8 is a hollow structure, and a plurality of slits 9 are provided above the collecting tank 8. The collecting tank 8 is connected to the nitrogen exhaust pipe 7, and the nitrogen exhaust pipe 7 is connected to the exhaust fan. Most of the liquid nitrogen will maintain a low temperature after gasification, and the low-temperature nitrogen will sink, so it is discharged through the collecting tank 8, the nitrogen exhaust pipe 7 and the exhaust fan.

[0024] Furthermore, protective baffles are provided on the operating side and the transmission side of the rolling mill, and protective plates are provided at the inlet and outlet of the plate and strip, and a gap is provided on the protective plate for the plate and strip 2 to enter and exit the rolling mill. The plate and strip 2 enter and exit the rolling mill through a narrow gap, and the atmosphere in the rolling mill is kept constant. After it is turned on, the gasified nitrogen is extracted from the inside of the rolling mill by the exhaust fan, and a slight negative pressure is maintained to ensure the cleanliness of the air around the rolling mill.

[0025] Furthermore, the liquid nitrogen distributor 6 includes a control valve and a liquid nitrogen pipe 10, and the side of the liquid nitrogen pipe 10 is provided with liquid nitrogen discharge holes 11 arranged at intervals, and each liquid nitrogen discharge hole 11 is connected to a two-fluid nozzle 4. An intermediate pipeline 12 and two side pipelines 13 arranged on both sides of the intermediate pipeline 12 are provided inside the liquid nitrogen pipe 10, and the intermediate pipeline 12 and the side pipeline 13 are separated by a partition. The intermediate pipeline 12 and the side pipeline 13 are respectively connected to three liquid nitrogen delivery pipes, each of which is connected to a control valve, and the liquid nitrogen flow rate is controlled by the control valve, so as to control and adjust the temperature of the roller 1. Liquid nitrogen discharge holes 11 are provided on the intermediate pipeline 12 and the side pipeline 13. Due to the normal use of the roller 1, the temperature of the side of the roller 1 will be slightly lower than that of the middle part. Dividing the liquid nitrogen pipe 10 into three sections can effectively solve the problem of inconsistent temperature of the roller 1.

[0026] Furthermore, the liquid nitrogen distributor 6 is connected to the liquid nitrogen storage tank through a liquid nitrogen pump, and the liquid nitrogen storage tank is connected to the liquid nitrogen generator.

[0027] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementations, which are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A rolling mill liquid nitrogen cooling system, characterized in that: It comprises a liquid nitrogen distributor (6), a compressed air pipeline (5) and a two-fluid nozzle (4) arranged at the roller (1); the compressed air in the compressed air pipeline (5) and the liquid nitrogen in the liquid nitrogen distributor (6) are combined in the two-fluid nozzle (4); the compressed air disperses the liquid nitrogen into small liquid nitrogen droplets; the small liquid nitrogen droplets are sprayed toward the roller (1) together with the compressed air; A trumpet-shaped cover body (3) is provided on the outside of the two-fluid nozzle (4), a collecting groove (8) is provided below the two-fluid nozzle (4), an air hole is provided on a side of the cover body (3) opposite to the collecting groove (8), a plurality of slits (9) are provided above the collecting groove (8), the collecting groove (8) is connected to a nitrogen exhaust pipe (7), and the nitrogen exhaust pipe (7) is connected to an exhaust fan; The operation side and the transmission side of the rolling mill are both provided with protective baffles, the strip inlet and outlet are provided with protective plates, and the protective plates are provided with gaps for the strip (2) to enter and exit the rolling mill; the liquid nitrogen distributor (6) comprises a control valve and a liquid nitrogen pipe (10); the side of the liquid nitrogen pipe (10) is provided with liquid nitrogen discharge holes (11) arranged at intervals, each liquid nitrogen discharge hole (11) is respectively connected to a two-fluid nozzle (4); the liquid nitrogen pipe (10) is provided with an intermediate pipeline (12) and two side pipelines (13) arranged on both sides of the intermediate pipeline (12); the intermediate pipeline (12) and the side pipeline (13) are respectively connected to three liquid nitrogen delivery pipes, each liquid nitrogen delivery pipe is connected to a control valve, and the liquid nitrogen flow rate is controlled by the control valve; the intermediate pipeline (12) and the side pipeline (13) are separated by a partition.

2. The rolling mill liquid nitrogen cooling system according to claim 1, characterized in that: The liquid nitrogen distributor (6) is connected to the liquid nitrogen storage tank via a liquid nitrogen pump.

3. The rolling mill liquid nitrogen cooling system according to claim 2, characterized in that: The liquid nitrogen storage tank is connected to the liquid nitrogen generator.

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