Heating furnace roller capable of improving furnace roller cooling efficiency

Abstract

The heating furnace roller comprises a furnace roller body, a plurality of roller rings and a circulating cooling system, and the circulating cooling system comprises a roller body water inlet pipe and a roller body water outlet pipe which are coaxially arranged; the positioning ring device is lined between the inner circumference of each roller ring and the outer circumference of the roller body of the furnace roller; the positioning ring device comprises positioning rings, roller ring water return pipes and roller ring water inlet pipes, the positioning rings are arranged on the outer circumference of the furnace roller body in a sleeving mode, and each roller ring is arranged on the outer circumference of the corresponding positioning ring in a sleeving mode. A multi-point water inlet and multi-point water outlet mode is adopted, compared with a traditional single-inlet and single-outlet structure, the amount of cooling water entering the positioning ring is increased, so that the cooling effect is improved, meanwhile, multi-path water outlet is achieved, a cooling dead zone in the positioning ring is eliminated, the temperature uniformity of the surface of the roll ring is improved, and the temperature of the surface of the roll ring is reduced; therefore, the service life of the furnace roller is prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of heating furnace rolls, and particularly relates to a heating furnace roll for improving the cooling efficiency of rolls. Background Art

[0002] The heating furnace is an important equipment for hot rolling production. The furnace roll is an important part of the heating furnace and undertakes the transportation function of the steel billet. Since the furnace roll is inside the heating furnace, in order to prevent the furnace roll from overheating and breaking, cooling water needs to be passed through the furnace roll, and the excess heat is taken away by the cooling water flowing in and out of the furnace roll. At present, the water-cooling structure of the furnace roll has poor cooling effect and uneven water-cooling phenomenon. In the production of some high-efficiency steel grades, this problem is particularly prominent.

[0003] For a cooling device of a heating furnace roll of a hot-dip galvanizing line in a Chinese utility model patent (authorized announcement number CN 203625444 U), the edge of the end water baffle of the auger structure adopts a plurality of arc-shaped grooves, which significantly reduces the water flow resistance of the end water baffle of the auger cage to the water flowing into the cooling roll and improves the cooling efficiency; the distribution of a plurality of springs avoids the blockage phenomenon caused by the resistance of the springs to the cooling water in the inner hole; however, there is still the phenomenon of uneven water-cooling, resulting in poor cooling effect. Summary of the Invention

[0004] The purpose of the invention is to solve the technical problem that the existing cooling effect of the heating furnace roll cannot meet the process requirements, and provide a heating furnace roll for improving the cooling efficiency of the roll.

[0005] To achieve the above purpose, the invention provides a heating furnace roll for improving the cooling efficiency of the roll, including a roll body of the furnace roll, a plurality of roll rings sleeved on the outer circumference of the roll body of the furnace roll along the axial direction of the roll body of the furnace roll, and a circulating cooling system. The circulating cooling system includes a roll body inlet pipe and a roll body outlet pipe arranged coaxially, and the roll body inlet pipe is arranged inside the roll body inlet pipe; it also includes a positioning ring device lined between the inner circumference of each roll ring and the outer circumference of the roll body of the furnace roll; the positioning ring device includes a positioning ring, a roll ring return water pipe and a roll ring inlet water pipe. The positioning ring is sleeved on the outer circumference of the roll body of the furnace roll, and each roll ring is sleeved on the outer circumference of the corresponding positioning ring; a plurality of roll ring inlet water pipes are evenly distributed along the outer circumference of the roll body of the furnace roll, and one end of each roll ring inlet water pipe sequentially passes through the roll body wall of the roll body of the furnace roll and the outlet pipe wall of the roll body outlet pipe until it is communicated with the roll body inlet pipe, and the other end of each roll ring inlet water pipe is fixed on the inner wall of the positioning ring and communicated with the inner cavity of the positioning ring; a plurality of roll ring return water pipes are evenly distributed along the outer circumference of the roll body of the furnace roll, and one end of each roll ring return water pipe passes through the roll body wall of the roll body of the furnace roll until it is communicated with the roll body outlet pipe and communicated with the inner cavity of the positioning ring, and the other end of each roll ring return water pipe is fixed on the inner wall of the positioning ring.

[0006] Further, the circulating cooling system further includes an inlet hose and an outlet hose. One end of the inlet hose passes through the shaft head at the end of the furnace roll body and extends to the roll body inlet pipe. One end of the outlet hose passes through the shaft head at the same side end of the furnace roll body and extends to the roll body outlet pipe, and the inlet hose and the outlet hose are locked by a rotary joint.

[0007] Further, the number of the roll ring return water pipes is the same as that of the roll ring inlet water pipes, and all the roll ring return water pipes and all the roll ring inlet water pipes are arranged alternately and evenly.

[0008] Further, a plurality of the roll rings are arranged evenly or unevenly.

[0009] Further, the diameters of the roll ring inlet water pipe and the roll ring outlet water pipe satisfy the formula D 2 = 0.8D 1 ~1.0D 1 where D 1 is the diameter of the roll ring inlet water pipe, and D 2 is the diameter of the roll ring outlet water pipe.

[0010] Further, the diameters of the roll body inlet water pipe and the roll body outlet water pipe satisfy the formula D 21 = 0.8D 11 ~0.9D 11 where D 11 is the diameter of the roll body inlet water pipe, and D 12 is the diameter of the roll body outlet water pipe.

[0011] Further, the number of the positioning ring cooling water inlets satisfies the following relationship:

[0012]

[0013] N is the number of the roll ring inlet water pipes.

[0014] Further, the cooling intensity h r of the roll ring satisfies the following formula:

[0015]

[0016] where h r is the cooling intensity when the roll ring contacts the furnace gas, α r is the contact surface coefficient of the roll ring contacting the heating atmosphere, σ is the black body radiation constant, T g is the furnace gas temperature, T r is the contact temperature of the roll ring and the furnace gas, and T e is the cooling water inlet temperature.

[0017] Further, the cooling intensity h n of the roll ring satisfies the following formula:

[0018]

[0019] Among them, h n is the cooling intensity when the roll body of the furnace roll contacts the furnace gas, and α n is the contact surface coefficient of the roll body of the furnace roll contacting the heating atmosphere, σ is the blackbody radiation constant, and T g is the furnace gas temperature, and T n is the outlet water temperature of the cooling water of the roll body of the furnace roll, and T e is the inlet water temperature of the cooling water.

[0020] Furthermore, the flow rate of the roll collar return water pipe 1 satisfies the following formula:

[0021] v e = w a h r + w b h n + v o

[0022] Among them, w a is the roll collar cooling coefficient, w b is the cooling coefficient of the roll body of the furnace roll, v e is the flow velocity of the cooling water at the inlet, and v o is the flow velocity of the cooling water at the outlet.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: By adopting the multi-point water inlet and multi-point water outlet method, compared with the traditional single-in and single-out structure, the amount of cooling water entering the positioning ring is increased, thereby improving the cooling effect. At the same time, with multi-channel water outlet, the cooling dead zone inside the positioning ring is eliminated, the temperature uniformity of the roll collar surface is improved, the temperature of the roll collar surface is reduced, and the service life of the furnace roll is extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is the structural diagram of the furnace roll of the heating furnace of the present invention;

[0025] Figure 2 is Figure 1 the structural schematic diagram of the positioning ring device in

[0026] Figure 3 the schematic diagram of the temperature distribution of the inlet and return water of the positioning ring;

[0027] Figure 4 is the schematic diagram of the temperature distribution of the roll collar. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The present invention will be further described below with reference to the drawings and specific embodiments.

[0029] As Figure 1The reheating furnace roller for improving the cooling efficiency of the roller shown includes a roller body 9 of the roller, a plurality of roller rings 8 sleeved on the outer circumference of the roller body 9 along the axial direction of the roller body 9 of the roller, and a circulating cooling system, a positioning ring device lined between the inner circumference of each roller ring 8 and the outer circumference of the roller body 9 of the roller, and the plurality of roller rings 8 are arranged uniformly or non-uniformly. The circulating cooling system includes a water inlet pipe 4 for the roller body, a water outlet pipe 5 for the roller body, a water inlet hose 6 and a water outlet hose 10. The water inlet pipe 4 for the roller body and the water outlet pipe 5 for the roller body are coaxially arranged and the water inlet pipe 4 for the roller body is internally placed in the water inlet pipe 4 for the roller body. One end of the water inlet hose 6 passes through the shaft head at the end of the roller body 9 of the roller and extends to the water inlet pipe 4 for the roller body, and one end of the water outlet hose 10 passes through the shaft head at the same-side end of the roller body 9 of the roller and extends to the water outlet pipe 5 for the roller body, and both the water inlet hose 6 and the water outlet hose 10 are locked by a rotary joint 7.

[0030] As Figure 2 The positioning ring device shown includes a positioning ring 3, a roller ring return water pipe 1 and a roller ring water inlet pipe 2. The positioning ring 3 is sleeved on the outer circumference of the roller body 9 of the roller, each roller ring 8 is sleeved on the outer circumference of the corresponding positioning ring 3, and the number of the roller ring return water pipes 1 is the same as the number of the roller ring water inlet pipes 2. The plurality of roller ring water inlet pipes 2 are uniformly distributed along the outer circumference of the roller body 9 of the roller, and one end of each roller ring water inlet pipe 2 sequentially passes through the roller body wall of the roller body 9 of the roller and the water outlet pipe wall of the water outlet pipe 5 for the roller body until it is communicated with the water inlet pipe 4 for the roller body, and the other end of each roller ring water inlet pipe 2 is fixed on the inner wall of the positioning ring 3 and is communicated with the inner cavity of the positioning ring 3; the plurality of roller ring return water pipes 1 are uniformly distributed along the outer circumference of the roller body 9 of the roller, and one end of each roller ring return water pipe 1 passes through the roller body wall of the roller body 9 of the roller until it is communicated with the water outlet pipe 5 for the roller body and is communicated with the inner cavity of the positioning ring 3, and the other end of each roller ring return water pipe 1 is fixed on the inner wall of the positioning ring 3; and all the roller ring return water pipes 1 and all the roller ring water inlet pipes 2 are arranged alternately and uniformly.

[0031] In the roller, the cooling water enters the water inlet pipe 4 for the roller body through the water inlet hose 6. During the process of flowing through the roller, a part of the cooling water cools the roller body 9 of the roller along the water inlet pipe 4 for the roller body and finally flows out through the water outlet hose 10 via the rotary joint 7, so as to cool the entire roller body 9 of the roller. Another part of the cooling water enters the plurality of roller ring water inlet pipes 2 on the outer circumference of the water inlet pipe 4 for the roller body. The cooling water flows into the positioning ring 3 through the plurality of roller ring water inlet pipes 2 to cool the circumference of the positioning ring 3, and the cooled water then enters the water outlet pipe 5 for the roller body from the roller ring return water pipe 1, and the water flowing back to the water outlet pipe 5 for the roller body flows out through the water outlet hose 10 via the rotary joint 7.

[0032] Let the diameter of the roller ring water inlet pipe 2 be D 1 and the diameter of the roller ring water outlet pipe 1 be D 2 and the diameter of the water inlet pipe 4 for the roller body be D 11 and the diameter of the water outlet pipe 5 for the roller body be D 12 ; in order for the cooling water to fill the positioning ring and completely eliminate the cooling dead zone, the diameters of the inlet and outlet of the roller ring should satisfy the relationship D 2= 0.8D 1 ~1.0D 1 ; For the purpose of filling the roll body with cooling water, the diameters of the water inlet and outlet of the roll body should satisfy the relationship D 21 = 0.8D 11 ~0.9D 11 .

[0033] The roll ring is fixed on the positioning ring by bolts in a gapless manner, avoiding the impact on the roll ring and thus affecting the smoothness of the waterway structure. In order to make the cooling water enter and exit quickly in the positioning ring, improve the cooling effect of the cooling water, and effectively reduce the surface temperature of the roll ring, the number of cooling water inlets of the positioning ring should satisfy the following relationship:

[0034]

[0035] N is the number of the inlet pipes 2 of the roll ring, that is, the roll ring area of the furnace roll in the present invention is divided into an N-way water inlet and an N-way water return structure.

[0036] The surface temperature of the furnace roll of the heating furnace is reduced by cooling water. For the roll ring, there is also special cooling water for cooling. The cooling intensity of the cooling water obeys the following formula:

[0037] Cooling intensity of the roll ring

[0038] Cooling intensity of the roll body of the furnace roll

[0039] Among them, h r is the cooling intensity when the roll ring contacts the furnace gas, h n is the cooling intensity when the roll body of the furnace roll contacts the furnace gas; α r is the contact surface coefficient when the roll ring contacts the heating atmosphere, taking 0.42; α n is the contact surface coefficient when the roll body of the furnace roll contacts the heating atmosphere, taking 0.53; σ is the Stefan-Boltzmann constant, with a value of 5.67×10-5 W / (m 2 .K 4 ); T g is the furnace gas temperature, T r is the contact temperature between the roll ring and the furnace gas, T n is the outlet temperature of the cooling water of the roll body of the furnace roll, T e is the inlet temperature of the cooling water.

[0040] The control of the return water flow needs to satisfy the formula v e = w a h r + w b h n + v o , where, w a is the cooling coefficient of the roll ring, w bis the cooling coefficient of the furnace roll body, v e is the inlet flow rate of the cooling water, v o is the outlet flow rate of the cooling water.

[0041] For the heating furnace roll that improves the cooling efficiency of the furnace roll by adopting the present invention, from Figure 3 、 Figure 4 it can be seen that the temperature of the roll ring is significantly reduced, the highest temperature is 991 °C, and it is reduced by 114 °C.

Claims

1. A furnace roller of a heating furnace for improving the cooling efficiency of a furnace roller, comprising a furnace roller body (9), a plurality of roller rings (8) sleeved on the outer circumference of the furnace roller body (9) along the axial direction of the furnace roller body (9), and a circulating cooling system, wherein the circulating cooling system comprises a roller body water inlet pipe (4) and a roller body water outlet pipe (5) arranged coaxially, and the roller body water inlet pipe (4) is built in the roller body water inlet pipe (4); the characteristics are: The invention also comprises a positioning ring device which is arranged between the inner circumference of each roller ring (8) and the outer circumference of the furnace roller body (9); the positioning ring device comprises a positioning ring (3), a roller ring water return pipe (1) and a roller ring water inlet pipe (2); the positioning ring (3) is sleeved on the outer circumference of the furnace roller body (9); each roller ring (8) is sleeved on the outer circumference of the corresponding positioning ring (3); a plurality of roller ring water inlet pipes (2) are evenly distributed along the outer circumference of the furnace roller body (9), and one end of each roller ring water inlet pipe (2) passes through the roller body wall, the roller body outlet pipe (1) and the roller body outlet pipe (2) in sequence. The water outlet pipe wall of the water pipe (5) is connected to the roller body water inlet pipe (4), and the other end of each roller ring water inlet pipe (2) is fixed on the inner wall of the positioning ring (3) and is connected to the inner cavity of the positioning ring (3); multiple roller ring return pipes (1) are evenly distributed along the outer circumference of the furnace roller body (9), and one end of each roller ring return pipe (1) passes through the roller body wall of the furnace roller body (9) until it is connected to the roller body water outlet pipe (5) and is connected to the inner cavity of the positioning ring (3), and the other end of each roller ring return pipe (1) is fixed on the inner wall of the positioning ring (3).

2. The heating furnace roller for improving the cooling efficiency of the furnace roller according to claim 1, characterized in that: The circulating cooling system also includes a water inlet hose (6) and a water outlet hose (10), one end of the water inlet hose (6) passes through the shaft head at the end of the furnace roller body (9) and extends to the roller body water inlet pipe (4), one end of the water outlet hose (10) passes through the shaft head at the same side end of the furnace roller body (9) and extends to the roller body water outlet pipe (5), and the water inlet hose (6) and the water outlet hose (10) are locked by a rotating joint (7).

3. The heating furnace roller for improving the cooling efficiency of the furnace roller according to claim 1, characterized in that: The number of the roller ring water return pipes (1) is the same as the number of the roller ring water inlet pipes (2), and all the roller ring water return pipes (1) and all the roller ring water inlet pipes (2) are alternately and evenly arranged.

4. The heating furnace roller for improving the cooling efficiency of the furnace roller according to claim 1, characterized in that: The plurality of roller rings (8) are arranged evenly or unevenly.

5. The heating furnace roller for improving the cooling efficiency of the furnace roller according to claim 1, characterized in that: The diameters of the roller ring water inlet pipe (2) and the roller ring water outlet pipe (1) satisfy the formula D2=0.8D1-1.0D1, where D1 is the diameter of the roller ring water inlet pipe (2) and D2 is the diameter of the roller ring water outlet pipe (1).

6. The heating furnace roller for improving the cooling efficiency of the furnace roller according to claim 1, characterized in that: The diameters of the roller body water inlet pipe (4) and the roller body water outlet pipe (5) satisfy the formula D 21 =0.8D 11 ~0.9D 11 , D 11 D is the diameter of the roller water inlet pipe (4), 12 is the diameter of the roller body water outlet pipe (5).

7. The heating furnace roller for improving the cooling efficiency of the furnace roller according to claim 1, characterized in that: The number of cooling water inlets of the positioning ring (3) satisfies the following relationship: N is the number of roller ring water inlet pipes 2.

8. The heating furnace roller for improving the cooling efficiency of the furnace roller according to claim 1, characterized in that: The cooling intensity h of the roller ring (8) r Satisfies the following formula: Among them, h r is the cooling intensity when the roller ring contacts the furnace gas, α r is the contact surface coefficient between the roller ring and the heated atmosphere, σ is the blackbody radiation constant, T g is the furnace gas temperature, T r is the contact temperature between the roller ring and the furnace gas, T e is the cooling water inlet temperature.

9. The heating furnace roller for improving the cooling efficiency of the furnace roller according to claim 1, characterized in that: The cooling intensity h of the roller ring (8) n Satisfies the following formula: Among them, h n is the cooling intensity when the furnace roller body contacts the furnace gas, α n is the contact surface coefficient between the furnace roller body and the heating atmosphere, σ is the black body radiation constant, T g is the furnace gas temperature, T n is the outlet temperature of the cooling water for the furnace roller body, T e is the cooling water inlet temperature.

10. The heating furnace roller for improving the cooling efficiency of the furnace roller according to claim 1, characterized in that: The flow rate of the roller ring return pipe (1) satisfies the following formula: v e =w a h r +w b h n +v o Among them, w a is the roller ring cooling coefficient, w b is the roller cooling coefficient, v e is the cooling water inlet flow rate, v o is the cooling water outlet flow rate.

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