Blowing system of heel end forging and pressing induction heating furnace

Abstract

The utility model provides a heel end forging and pressing induction heating furnace purging system which comprises a plurality of Laval nozzle assemblies which are evenly distributed and fixedly arranged in a refractory layer of an induction heating furnace and located on the periphery of an induction heating coil in the induction heating furnace. The input ends of the Laval nozzle assemblies are connected with compressed air through electromagnetic valves, and the output ends of the Laval nozzle assemblies spray the compressed air to effectively cover the whole section of a steel rail located in the induction heating furnace and remove oxide skin attached to the surface of the steel rail at high temperature. The device does not need to be manually held by hands to frequently go deep into the heating device for sequential front-back purging, so that metal surface oxide skin can be effectively, safely and conveniently removed when the steel rail is inductively heated to high temperature in an induction furnace, the accuracy and controllability of induction heating temperature detection are improved, and the device is safe, reliable and long in service life.

Description

Technical Field

[0001] The utility model relates to the technical field of heat treatment, in particular to a purge system of a heel forging induction heating furnace. Background Art

[0002] With the rapid development of railway transportation, the requirements for the smoothness of train operation are becoming higher and higher. In order to further improve the safety and reliability of operation, the China Railway Corporation currently requires that both turnouts and main lines use online heat-treated rails. At the same time, the asymmetric section point rails, heart rails and special-shaped rails for connecting different rail types, which are key components of the turnouts, are partially hot-forged into another standard rail that can be easily connected to the line. In order to improve the quality of the forging and heat treatment of the rail profile, the industry currently generally uses induction heating furnaces for the forging and heat treatment of the rail profile. During the heating process, as the heating temperature gradually increases, different degrees of oxide scale will appear on the surface of the rail, thereby interfering with the accurate display and judgment of the temperature by the infrared thermometer system during the heating process, which can easily cause the displayed temperature to be low, the actual temperature to be too high and overheated, resulting in the scrapping of the rail, which seriously affects the stability and controllability of product quality. In addition, the use of high-pressure air ducts by operators to blow metal oxide scales deep into the furnace also poses certain safety hazards and illegal operations.

[0003] At present, in order to further reduce the adverse effects of oxide scale during rail heating, the prior art arranges an air isolation component on the heating device. The isolation component includes an air duct and a cooling pipe. Inert gas is introduced into the air duct to purge the area to be tested. The cooling pipe is sleeved on the outside of the air duct to cool the air duct. This device reduces the temperature measurement error during rail heating. However, the air isolation component needs to be held frequently and deeply inside the heating device for forward and backward purge in turn, which has high work intensity, low efficiency and is unsafe. Utility Model Content

[0004] The utility model provides a purge system for a heel-end forging induction heating furnace, so as to solve the technical problems of high work intensity, low efficiency and unsafety in the existing oxide skin removal technology in the process of rail heating.

[0005] The technical solution adopted by the utility model is as follows:

[0006] A heel forging induction heating furnace purge system, comprising:

[0007] A plurality of Laval nozzle assemblies are evenly distributed and fixedly arranged in the refractory layer of the induction heating furnace and located at the periphery of the induction heating coil in the induction heating furnace. The input ends of the Laval nozzle assemblies are connected to compressed air through solenoid valves, and the output ends spray compressed air to effectively cover the entire cross-section of the rails in the induction heating furnace and remove the oxide scale attached to the surface under high temperature.

[0008] Furthermore, the Laval nozzle assembly is arranged in a ring shape along the induction heating furnace mouth of the induction heating furnace, and is fixedly arranged in the refractory layer of the induction heating furnace in a full-section chessboard-like node distribution along the length direction of the induction heating furnace and is located outside the induction heating coil in the induction heating furnace.

[0009] Furthermore, the Laval nozzle assemblies are installed at intervals in the gaps between adjacent induction heating coils in the length direction of the induction heating furnace.

[0010] Furthermore, the Laval nozzle assembly includes a Laval nozzle, a compressed air input pipe, a cooling water input pipe, and a cooling water output pipe.

[0011] The Laval nozzle is provided with a contraction section, a throat section, and an expansion section in sequence along the gas injection direction. The input end of the contraction section is connected to the compressed air input pipe. The compressed air passes through the guide section, the contraction section, and the throat section in the compressed air input pipe in sequence and is ejected from the expansion section. A cooling channel is also embedded between the inner wall and the outer wall of the contraction section. The cooling channel is an annular hollow structure, and the top is respectively connected to the cooling water input pipe and the cooling water output pipe. After the cooling water flows into the cooling channel from the cooling water input pipe for heat exchange, the heat is taken away by the cooling water output pipe flow.

[0012] Furthermore, the cooling water input pipe and the cooling water output pipe are symmetrically arranged along the radial direction of the cross section of the cooling channel.

[0013] Furthermore, a surface of the Laval nozzle assembly facing the inner side of the furnace chamber of the induction heating furnace is provided with a high temperature resistant coating.

[0014] Furthermore, the aperture of the guide section is Φ8-Φ16 mm;

[0015] The length of the throat section is greater than 10 mm, and the aperture is Φ1.5 to Φ4.5 mm;

[0016] The maximum aperture of the expansion section is Φ20 mm.

[0017] Furthermore, it also includes a PLC programmable controller, which is connected to the solenoid valve circuit and is used to control the opening and closing of the solenoid valve according to the set temperature and time interval as needed during the induction heating process of the rail, so that the Laval nozzle assembly sprays compressed air into the induction heating furnace at the set temperature and at the set time interval to remove the oxide scale attached to the surface of the rail.

[0018] Furthermore, the compressed air input pipe and the nozzle are detachably connected via a connecting thread;

[0019] The top of the cooling channel is provided with two threaded holes, and the cooling water input pipe and the cooling water output pipe are detachably connected to the two threaded holes through connecting threads.

[0020] Furthermore, the throat section and the expansion section are detachably connected via a connecting thread, and the throat section and the expansion section are an integrated structure.

[0021] The utility model has the following beneficial effects:

[0022] The present application provides a purge system for a heel-end forging induction heating furnace, comprising a plurality of Laval nozzle assemblies, wherein the Laval nozzle assemblies are evenly distributed and fixedly arranged in the refractory layer of the induction heating furnace and are located at the periphery of the induction heating coil in the induction heating furnace, the input ends of the Laval nozzle assemblies are connected to compressed air through solenoid valves, and the output ends spray compressed air to effectively cover the entire cross-section of the rails located in the induction heating furnace and remove the oxide scale attached to the surface under high temperature. Since the present application can spray compressed air to remove the oxide scale attached to the rails under high temperature through a plurality of Laval nozzle assemblies evenly distributed and fixedly arranged in the refractory layer of the induction heating furnace and located at the periphery of the induction heating coil in the induction heating furnace, there is no need for manual hand-held frequent deep-diving into the interior of the heating device for sequential front and back purge, thereby achieving effective, safe and convenient removal of the oxide scale on the metal surface when the rails are inductively heated to a high temperature in the induction furnace, thereby improving the accuracy and controllability of the induction heating temperature detection. At the same time, since the Laval nozzle assembly is fixed in the refractory layer and is located at the periphery of the induction heating coil in the induction heating furnace, the influence of high temperature on the Laval nozzle assembly can be effectively avoided, thereby ensuring reliability and service life.

[0023] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0025] Figure 1 It is a schematic longitudinal section diagram of a Laval nozzle assembly according to a preferred embodiment of the utility model.

[0026] Figure 2 It is a bottom view schematic diagram of a Laval nozzle assembly according to a preferred embodiment of the utility model.

[0027] Figure 3 It is a schematic diagram of a heel forging induction heating furnace with a purge system and a rail according to a preferred embodiment of the utility model.

[0028] Figure 4 It is a schematic diagram of the distribution and purging operation of the Laval nozzle assembly of the induction heating furnace mouth of the preferred embodiment of the utility model.

[0029] Described in the figure: 1. compressed air input pipe; 2. cooling water input pipe; 3. cooling water; 4. nozzle; 5. compressed air; 6. Laval nozzle assembly; 7. refractory layer; 8. induction heating furnace; 9. induction heating coil; 10. rail; 11. induction heating furnace mouth; 12. cooling water output pipe; 13. guide section; 14. cooling channel; 15. contraction section; 16. connecting thread; 17. expansion section; 18. throat section. DETAILED DESCRIPTION

[0030] The embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. However, the present invention can be implemented in a variety of different ways as defined and covered below.

[0031] Reference Figure 3 and Figure 4 The preferred embodiment of the utility model provides a heel-end forging induction heating furnace purge system, comprising:

[0032] A plurality of Laval nozzle assemblies 6 are evenly distributed and fixedly arranged in the refractory layer 7 of the induction heating furnace 8 and located at the periphery of the induction heating coil 9 in the induction heating furnace 8. The input ends of the Laval nozzle assemblies 6 are connected to the compressed air 5 through the solenoid valves, and the compressed air 5 is ejected from the output ends to effectively cover the entire cross-section of the rails 10 in the induction heating furnace 8 and remove the oxide scale attached to the surface under high temperature.

[0033] The present embodiment provides a purge system for a heel-end forging induction heating furnace, including a plurality of Laval nozzle assemblies 6, wherein the Laval nozzle assemblies 6 are evenly distributed and fixedly arranged in the refractory layer 7 of the induction heating furnace 8 and are located outside the induction heating coil 9 in the induction heating furnace 8, and the input ends of the Laval nozzle assemblies 6 are connected to compressed air 5 through solenoid valves, and the compressed air 5 is ejected from the output ends to effectively cover the entire cross-section of the rail 10 located in the induction heating furnace 8 and remove the oxide scale attached to the surface under high temperature. Since the present application can remove the oxide scale attached to the rail 10 under high temperature by ejecting compressed air from the plurality of Laval nozzle assemblies 6 evenly distributed and fixedly arranged in the refractory layer 7 of the induction heating furnace 8 and are located outside the induction heating coil 9 in the induction heating furnace 8, The oxide scale is removed without the need for manual hand-held frequent deep-into-the-heating device to blow back and forth in sequence, reducing the unsafe and labor-intensive problems caused by manual removal of oxide scale, solving the interference problem of inaccurate temperature measurement in the current induction heating furnace, and improving the induction heating effect and quality, so that the rail 10 can be effectively, safely and conveniently removed from the metal surface oxide scale when it is inductively heated to a high temperature in the induction furnace, thereby improving the accuracy and controllability of induction heating temperature detection. At the same time, since the Laval nozzle assembly 6 is fixed in the refractory layer 7 and is located outside the induction heating coil 9 in the induction heating furnace 8, the high temperature generated by the induction heating coil 9 can be effectively avoided. The influence of the Laval nozzle assembly 6 on the Laval nozzle assembly 6 can be ensured, thereby ensuring the reliability and service life of the Laval nozzle assembly 6.

[0034] In another preferred embodiment of the present application, the Laval nozzle assembly 6 is arranged in a ring shape along the induction heating furnace mouth 11 of the induction heating furnace 8, and is fixedly arranged in the refractory layer 7 of the induction heating furnace 8 in a full-section checkerboard-like node distribution along the length direction of the induction heating furnace 8 and is located outside the induction heating coil 9 in the induction heating furnace 8.

[0035] This embodiment adopts an annular, full-section chessboard node distribution method for the Laval nozzle assembly 6 to ensure that the metal surface oxide scale can be removed in an all-round, efficient, safe and convenient manner when the rail 10 is inductively heated to a high temperature in the induction furnace, thereby improving the accuracy and controllability of induction heating temperature detection, avoiding dead corners for removing the metal surface oxide scale, and ensuring the removal effect of the metal surface oxide scale. In other words, this embodiment can ensure that the entire cross-section of the rail 10 heated deep in the furnace is purged and cleared of the high-temperature surface oxide scale through the above-mentioned arrangement, thereby improving the accuracy of heating temperature control, avoiding the distortion of temperature detection caused by oxide scale obstruction, thereby causing overheating and overburning caused by continuous heating, reducing the labor intensity and skill requirements of operators, and improving heating efficiency and quality.

[0036] In another preferred embodiment of the present application, the Laval nozzle assemblies 6 are installed at intervals in the gaps between adjacent induction heating coils 9 in the length direction of the induction heating furnace 8 .

[0037] In this embodiment, the Laval nozzle assembly 6 can not only be effectively embedded in the limited space where the induction heating coil 9 is wound, thereby reducing the sparse magnetic lines caused by the excessive gap of the induction heating coil 9, but also has the effect of low-pressure air intake and high-pressure ejection, thereby being able to more effectively blow away the oxide scale, while facilitating the replacement of the nozzle after local damage, thereby reducing the replacement and maintenance costs.

[0038] In another preferred embodiment of the present application, Figure 1 and Figure 2 As shown, the Laval nozzle assembly 6 includes a Laval nozzle 4, a compressed air input pipe 1, a cooling water input pipe 2, and a cooling water output pipe 12. The Laval nozzle 4 is provided with a contraction section 15, a throat section 18, and an expansion section 17 in sequence along the gas injection direction. The input end of the contraction section 15 is connected to the compressed air input pipe 1. The compressed air 5 passes through the guide section 13, the contraction section 15, and the throat section 18 in the compressed air input pipe 1 in sequence and is ejected from the expansion section 17. A cooling channel 14 is also embedded between the inner wall and the outer wall of the contraction section 15. The cooling channel 14 is an annular hollow structure, and the top is respectively connected to the cooling water input pipe 2 and the cooling water output pipe 12. After the cooling water 3 flows from the cooling water input pipe 2 into the cooling channel 14 for heat exchange, the heat is taken away by the cooling water output pipe 12.

[0039] In addition to the Laval nozzle 4, the Laval nozzle assembly 6 of this embodiment is also embedded with a cooling channel 14. When working, the solenoid valve body is opened at high temperature, and the compressed air inlet pipe 1 allows the set compressed air 5 to enter the contraction section 15 and the throat section 18 of the Laval nozzle 4 from the guide section 13. After a short period of pressure accumulation and rectification in the throat section 18, it is accelerated to be ejected through the expansion section 17. At the same time, the cooling water inlet pipe 2 and the cooling water outlet pipe 12 continuously provide circulating water flow to cool the heated Laval nozzle 4, thereby ensuring its normal operation and ensuring the reliability and service life of the Laval nozzle assembly 6.

[0040] In a preferred embodiment of the present application, the cooling water inlet pipe 2 and the cooling water outlet pipe 12 are symmetrically arranged along the radial direction of the cross-section of the cooling channel 14, so as to maximize the length of the flow path of the cooling water between the cooling water inlet pipe 2 and the cooling water outlet pipe 12, improve the heat exchange efficiency of the cooling channel 14, ensure the normal operation of the Laval nozzle assembly 6, and ensure its reliability and service life.

[0041] In a preferred embodiment of the present application, the surface of the Laval nozzle assembly 6 facing the inner side of the furnace chamber of the induction heating furnace 8 is provided with a high-temperature resistant coating, such as a phenolic resin high-temperature resistant coating, etc., which further provides heat insulation protection for the Laval nozzle assembly 6, ensures its normal operation, and ensures the reliability and service life of the Laval nozzle assembly 6.

[0042] In the preferred embodiment of the present application, the aperture of the guide section 13 is Ф8~Ф16mm, which has the advantage of ensuring sufficient amount of compressed air entering and controlling the volume of the input pipeline to a certain range. At the same time, this aperture is convenient for forming a reasonable compression ratio with the throat aperture, and is also conducive to manufacturing and installation layout.

[0043] The throat section 18 is longer than 10 mm and has an aperture of Φ1.5 to Φ4.5 mm, which can not only meet the function of rectifying, gathering pressure and accelerating the ejected airflow, but also meet the need of arranging multiple nozzles in the effective space to blow away the oxide scale.

[0044] The maximum aperture of the expansion section 17 is 20 mm, which has the advantage of ensuring that the outlet compressed air blowing can cover the rail surface as much as possible while reducing the number of nozzle arrangements without significantly reducing the blowing pressure and effect.

[0045] In a preferred embodiment of the present application, the heel-end forging induction heating furnace purging system also includes a PLC programmable controller, which is connected to the solenoid valve circuit and is used to control the opening and closing of the solenoid valve according to the set temperature and time interval as needed during the induction heating process of the rail 10, so that the Laval nozzle assembly 6 sprays compressed air 5 into the induction heating furnace 8 at the set temperature and at the set time interval to remove the oxide scale attached to the surface of the rail 10.

[0046] In this embodiment, through the PLC programmable controller and the solenoid valve, during the induction heating process of the rail 10, compressed air can be sprayed into the furnace chamber at different temperatures and time intervals (such as a purge time of 2-3s and an interval time of 5-6s) as needed to effectively remove the oxide scale attached to the metal surface, thereby effectively improving the degree of automation of oxide scale removal, thereby further reducing the labor intensity and skill requirements of operators, and improving heating efficiency and quality. The specific control logic is a simple application of commonly used technology, and those skilled in the art can make adaptive adjustments as needed, and there is no improvement in software and methods.

[0047] In a preferred embodiment of the present application, the compressed air input pipe 1 and the Laval nozzle 4 are detachably connected via a connecting thread 16 .

[0048] In this embodiment, the compressed air input pipe 1 and the Laval nozzle 4 of the Laval nozzle assembly 6 adopt a split structure and are detachably connected via a connecting thread 16, so as to facilitate timely replacement after local damage and reduce replacement and maintenance costs.

[0049] In a preferred embodiment of the present application, two threaded holes are provided at the top of the cooling channel 14 , and the cooling water inlet pipe 2 and the cooling water outlet pipe 12 are detachably connected to the two threaded holes respectively through connecting threads 16 .

[0050] In this embodiment, the cooling channel 14 of the Laval nozzle assembly 6 and the cooling water inlet pipe 2 and the cooling water outlet pipe 12 adopt a split structure and are detachably connected via connecting threads 16, so as to facilitate timely replacement after local damage and reduce replacement and maintenance costs.

[0051] In a preferred embodiment of the present application, the throat section 18 and the expansion section 17 are detachably connected via a connecting thread 16 , and the throat section 18 and the expansion section 17 are an integrated structure.

[0052] In this embodiment, the throat section 18 and the expansion section 17 of the Laval nozzle 4 are designed as a split structure, which is detachably connected through the connecting thread 16, so as to facilitate timely replacement after local damage and reduce replacement and maintenance costs.

[0053] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A heel forging induction heating furnace purge system, characterized in that: include: A plurality of Laval nozzle assemblies (6) are evenly distributed and fixedly arranged in a refractory layer (7) of an induction heating furnace (8) and located outside an induction heating coil (9) in the induction heating furnace (8). The input ends of the Laval nozzle assemblies (6) are connected to compressed air (5) through electromagnetic valves, and the compressed air (5) ejected from the output ends effectively covers the entire cross-section of a steel rail (10) located in the induction heating furnace (8) and removes oxide scale attached to the surface at high temperature.

2. The heel end forging induction heating furnace purging system according to claim 1 is characterized in that: The Laval nozzle assembly (6) is arranged in a ring shape along the induction heating furnace mouth (11) of the induction heating furnace (8), and is fixedly arranged in a full-section chessboard-like node distribution along the length direction of the induction heating furnace (8) in the refractory layer (7) of the induction heating furnace (8) and is located outside the induction heating coil (9) in the induction heating furnace (8).

3. The heel end forging induction heating furnace purging system according to claim 2 is characterized in that: The Laval nozzle assembly (6) is installed at intervals in the gap between adjacent induction heating coils (9) in the length direction of the induction heating furnace (8).

4. The heel end forging induction heating furnace purging system according to claim 1 is characterized in that: The Laval nozzle assembly (6) comprises a Laval nozzle (4), a compressed air input pipe (1), a cooling water input pipe (2), and a cooling water output pipe (12). The Laval nozzle (4) is provided with a contraction section (15), a throat section (18), and an expansion section (17) in sequence along the gas injection direction. The input end of the contraction section (15) is connected to the compressed air input pipe (1). The compressed air (5) passes through the guide section (13), the contraction section (15), and the throat section (18) in the compressed air input pipe (1) in sequence and is then ejected from the expansion section (17). A cooling channel (14) is also embedded between the inner wall and the outer wall of the contraction section (15). The cooling channel (14) is an annular hollow structure, and the top is respectively connected to the cooling water input pipe (2) and the cooling water output pipe (12). After the cooling water (3) flows from the cooling water input pipe (2) into the cooling channel (14) for heat exchange, the heat is taken away by the cooling water output pipe (12).

5. The heel end forging induction heating furnace purging system according to claim 4 is characterized in that: The cooling water inlet pipe (2) and the cooling water outlet pipe (12) are symmetrically arranged along the radial direction of the cross section of the cooling channel (14).

6. The heel end forging induction heating furnace purging system according to claim 1 is characterized in that: The surface of the Laval nozzle assembly (6) facing the inner side of the furnace chamber of the induction heating furnace (8) is provided with a high temperature resistant coating.

7. The heel end forging induction heating furnace purging system according to claim 5, characterized in that: The aperture of the guide section (13) is Φ8-Φ16 mm; The throat section (18) is longer than 10 mm and has a hole diameter of 1.5 to 4.5 mm. The maximum aperture of the expansion section (17) is Φ20 mm.

8. The heel end forging induction heating furnace purging system according to claim 1 is characterized in that: It also includes a PLC programmable controller, which is connected to the solenoid valve circuit and is used to control the opening and closing of the solenoid valve according to the set temperature and time interval as required during the induction heating process of the rail (10), so that the Laval nozzle assembly (6) sprays compressed air (5) into the induction heating furnace (8) at the set temperature and at the set time interval to remove the oxide scale attached to the surface of the rail (10).

9. The heel end forging induction heating furnace purging system according to claim 4, characterized in that: The compressed air input pipe (1) and the Laval nozzle (4) are detachably connected via a connecting thread (16); Two threaded holes are provided at the top of the cooling channel (14), and the cooling water input pipe (2) and the cooling water output pipe (12) are detachably connected to the two threaded holes via connecting threads (16).

10. The heel end forging induction heating furnace purging system according to claim 4 or 9, characterized in that: The throat section (18) and the expansion section (17) are detachably connected via a connecting thread (16), and the throat section (18) and the expansion section (17) are an integrated structure.

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