Vacuum hydrogen furnace

Abstract

This invention provides a vacuum hydrogen furnace, relating to the technical field of heat treatment equipment for soft magnetic materials and other materials requiring hydrogen reduction. The vacuum hydrogen furnace includes a base frame, furnace shell, furnace door, hydrogen purification and delivery device, and cooling system. In this invention, a vacuum pump unit evacuates the interior of the furnace shell into a vacuum, and then a corresponding amount of purified hydrogen is introduced according to the size of the parts. The hydrogen delivery rate is controlled by a mass flow meter and a pressure sensor. A full hydrogen atmosphere is not required; achieving the material reduction effect is sufficient. The amount of hydrogen used is very small, and because of this small amount, it can be treated and discharged through a commercially available non-combustion hydrogen exhaust system, eliminating the need for combustion and ensuring safety and environmental friendliness. Two sets of linear actuators and a crank rotate the end cap along the connection point of the first and second lugs, effectively closing and opening the end cap and the vent pipe. This prevents heat loss from the furnace shell through the buffer tank during operation and avoids damage to the hydrogen delivery pipe and vacuum pipeline due to high temperatures.

Description

Technical Field

[0001] This invention relates to the technical field of heat treatment equipment for soft magnetic materials and other materials that require hydrogen reduction, specifically a vacuum hydrogen furnace. Background Technology

[0002] Soft magnetic materials, powder metallurgy, and ceramic metallization all require hydrogen reduction heat treatment processes. After being processed into parts, soft magnetic materials must undergo annealing heat treatment to obtain good soft magnetic properties. However, during annealing heat treatment, some metal elements in the soft magnetic materials may be oxidized at high temperatures. Therefore, hydrogen is generally used as a protective gas. Hydrogen has reducing properties and can reduce some metal oxides when heated, thereby improving the quality of soft magnetic materials. In actual processing, the amount of hydrogen required will vary depending on the size of the parts being processed. The traditional approach is to use a full hydrogen atmosphere, and then release and burn the hydrogen after the operation is completed. This results in a large amount of hydrogen used and is not safe or environmentally friendly. Summary of the Invention

[0003] Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a vacuum hydrogen furnace, which solves the problems of traditional hydrogen reduction heat treatment processes that use a full hydrogen atmosphere, are then discharged and burned after the process is completed, resulting in large hydrogen consumption and insufficient safety and environmental protection.

[0004] Technical solution To achieve the above objectives, the present invention provides the following technical solution: a vacuum hydrogen furnace, comprising a base frame, a furnace shell, a furnace door, a hydrogen purification and conveying device, and a cooling system. An explosion-proof valve is installed on the upper wall of the furnace shell. A workbench is fixedly connected to the lower inner wall of the furnace shell. Multiple sets of heaters are installed on the inner wall of the furnace shell. The cooling system is located on the right side of the furnace shell. An expansion pipe is installed on the side of the furnace shell away from the cooling system. A buffer box is fixedly connected to the side of the expansion pipe away from the furnace shell via a connecting flange. A control device for evacuating the interior of the furnace shell and filling it with hydrogen is provided between the buffer box and the furnace shell. The control device includes: a vent pipe, which is fixedly connected to the connecting flange on the side away from the expansion pipe and located inside the buffer box; an end cap for separating the interior of the furnace shell from the buffer box during furnace shell operation, the end cap being rotatably connected to the end of the vent pipe away from the connecting flange via a first lug, a second lug, and a pivot pin; and a drive assembly for closing the end cap, the drive assembly being fixed via two sets of connecting seats. The system comprises: a fixed connection to the upper wall of the buffer tank; a linkage structure for transmission between the drive assembly and the end cover, the linkage structure being rotatably connected to the drive assembly via a rotating rod; a first sealing structure for sealing between the connecting seat and the drive assembly, the first sealing structure being disposed on the inner wall of the connecting seat; a second sealing structure for sealing between the end cover and the vent pipe, the second sealing structure being disposed between the end cover and the vent pipe; a heat insulation structure disposed on the furnace shell, the vent pipe, the end cover, and the inner wall of the buffer tank; a vacuum assembly disposed at the end of the buffer tank away from the connecting flange; a hydrogen delivery pipe for conveying hydrogen, the hydrogen delivery pipe being fixedly connected to the rear wall of the buffer tank, the end of the hydrogen delivery pipe away from the buffer tank being fixedly connected to a hydrogen purification and delivery device; a quantitative delivery structure for controlling the precise delivery of hydrogen, the quantitative delivery structure being disposed on the outer wall of the hydrogen delivery pipe; and an exhaust system for venting exhaust after operation, the exhaust system being fixedly connected to the lower wall of the buffer tank.

[0005] Preferably, the drive assembly includes two sets of linear actuators. The two sets of linear actuators are respectively fixedly connected to the upper wall of the buffer box in a front-to-back manner through a set of connecting seats. The extension shaft of the linear actuator passes through the inner wall of the connecting seat and the upper wall of the buffer box and extends into the interior of the buffer box. The ends of the extension shafts of the two sets of linear actuators are threaded with connectors. The rotating rod is rotatably connected between the two sets of connectors.

[0006] Preferably, the linkage structure includes a third lug and a crank. The third lug is fixedly connected to the end of the end cap away from the vent pipe, and the crank is rotatably connected between the rotating rod and the third lug.

[0007] Preferably, the first sealing structure includes two sets of sealing rings, which are arranged vertically on the inner sidewall of the connecting seat.

[0008] Preferably, the second sealing structure is a sealing gasket, which is fixedly connected to the end of the end cap facing the vent pipe, and the sealing gasket is made of fire-resistant fiber felt.

[0009] Preferably, the heat insulation structure includes a first inner liner, a second inner liner, a third inner liner, and a fourth inner liner. The first inner liner is disposed on the inner wall of the furnace shell, the second inner liner is disposed on the inner wall of the buffer box, the third inner liner is disposed on the inner wall of the vent pipe, and the fourth inner liner is disposed on the inner wall of the end cover and located between the end cover and the second sealing structure.

[0010] Preferably, the vacuum assembly includes a bracket and a vacuum pump unit. The vacuum pump unit is fixedly connected to the end of the buffer box away from the connecting flange via a vacuum pipe, and the bracket is fixedly connected to the lower wall of the vacuum pump unit.

[0011] Preferably, the quantitative delivery structure includes a pressure sensor, a mass flow meter, and a flame arrester, which are fixedly connected to the outer wall of the hydrogen delivery pipe in order of proximity to the buffer tank.

[0012] Beneficial effects This invention provides a vacuum hydrogen furnace. It has the following beneficial effects: Compared to existing technologies, this vacuum hydrogen furnace first creates a vacuum inside the furnace shell using a vacuum pump unit. Then, a corresponding amount of purified hydrogen is introduced based on the size of the parts. The hydrogen delivery volume is controlled by a mass flow meter and a pressure sensor. It does not require a full hydrogen atmosphere; it only needs to achieve the material reduction effect. The amount of hydrogen used is very small, and because the amount of hydrogen used is small, it can be discharged after being treated by a commercially available non-combustion hydrogen exhaust system. It does not require combustion and is safe and environmentally friendly.

[0013] Compared to existing technologies, this vacuum hydrogen furnace uses two sets of linear actuators and a crank to rotate the end cover along the connection point of the first and second lugs, which serves to close and open the end cover and the vent pipe. This prevents heat loss from the furnace shell during operation, thus reducing heat loss and also preventing the hydrogen delivery pipe and vacuum pipeline from being damaged by high temperatures. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 For the present invention Figure 1 Schematic diagram of the cross section along the AA direction; Figure 3 This is a top view of the overall structure of the present invention; Figure 4 This is a schematic diagram of the rear side of the overall structure of the present invention; Figure 5 This is a partial cross-sectional view of the internal structure of the buffer box of the present invention; Figure 6 This is a partial side view of the connecting structure of the rotating rod, crank, and third lug of the present invention; Figure 7 This is a partial cross-sectional view of the internal structure of the end cap and vent pipe of the present invention.

[0015] The components are as follows: 1. Base frame; 2. Furnace shell; 3. Explosion-proof valve; 4. Furnace door; 5. Cooling system; 6. Support; 7. Vacuum pump set; 8. Vacuum pipeline; 9. Exhaust system; 10. Buffer box; 11. Linear actuator; 12. Connecting seat; 13. First inner liner; 14. Heater; 15. Workbench; 16. Hydrogen delivery pipe; 17. Flame arrester; 18. Mass flow meter; 19. Pressure sensor; 20. Expansion tube; 21. Connecting flange; 22. Vent pipe; 23. First hanging lug; 24. Second hanging lug; 25. End cap; 26. Third hanging lug; 27. Crank; 28. Connector; 29. ​​Second inner liner; 30. Sealing ring; 31. Third inner liner; 32. Fourth inner liner; 33. Sealing gasket; 34. Rotating rod. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Example: like Figures 1 to 7 As shown, this embodiment of the invention provides a vacuum hydrogen furnace, including a base frame 1, a furnace shell 2, a furnace door 4, a hydrogen purification and conveying device, and a cooling system 5. An explosion-proof valve 3 is installed on the upper wall of the furnace shell 2. A workbench 15 is fixedly connected to the lower inner wall of the furnace shell 2. Multiple sets of heaters 14 are installed on the inner wall of the furnace shell 2. The cooling system 5 is located on the right side of the furnace shell 2. An expansion pipe 20 is installed on the side of the furnace shell 2 away from the cooling system 5. A buffer box 10 is fixedly connected to the side of the expansion pipe 20 away from the furnace shell 2 via a connecting flange 21. A control device for evacuating the interior of the furnace shell 2 and filling it with hydrogen is installed between the buffer box 10 and the furnace shell 2. The control device includes: a vent pipe 22, an end cap 25 for separating the interior of the furnace shell 2 from the buffer box 10 during furnace shell 2 operation, a drive assembly for driving the end cap 25 to close, a linkage structure for transmission between the drive assembly and the end cap 25, a first sealing structure for sealing between the connecting seat 12 and the drive assembly, a second sealing structure for sealing between the end cap 25 and the vent pipe 22, a heat insulation structure, a vacuum assembly, a hydrogen delivery pipe 16 for delivering hydrogen, a quantitative delivery structure for controlling the precise delivery of hydrogen, and an exhaust system 9 for exhausting gas after the operation is completed. The vent pipe 22 is fixedly connected to the connecting flange 21 on the side away from the expansion pipe 20 and located inside the buffer box 10. The end cap 25 is rotatably connected to the end of the vent pipe 22 away from the connecting flange 21 via the first lug 23, the second lug 24, and the pivot pin. A heat insulation structure is provided on the inner walls of the furnace shell 2, the vent pipe 22, the end cap 25, and the buffer box 10. The heat insulation structure includes a first inner liner 13, a second inner liner 29, a third inner liner 31, and a fourth inner liner 32. The first inner liner 13 is located on the inner wall of the furnace shell 2, and the second inner liner 29 is located on the inner wall of the furnace shell 2. The inner wall of the buffer box 10, the third inner liner 31 is set on the inner wall of the vent pipe 22, and the fourth inner liner 32 is set on the inner wall of the end cover 25 and located between the end cover 25 and the second sealing structure. The first inner liner 13 and the second inner liner 29 are used to prevent the heat inside the furnace shell 2 and the buffer box 10 from spreading outward. The third inner liner 31 and the fourth inner liner 32 are used to prevent the heat from being transferred from the internal heat box buffer box 10 when the furnace shell 2 is in operation, so as to avoid excessive heat loss. They also serve to protect the vacuum pump group 7, the vacuum pipeline 8 and the hydrogen delivery pipe 16. The drive assembly is fixedly connected to the upper wall of the buffer box 10 via two sets of connecting seats 12. The drive assembly includes two sets of linear actuators 11. The two sets of linear actuators 11 are respectively fixedly connected to the upper wall of the buffer box 10 in a front-to-back manner via a set of connecting seats 12. The extension shaft of the linear actuator 11 passes through the inner wall of the connecting seat 12 and the upper wall of the buffer box 10 and extends into the interior of the buffer box 10. The ends of the extension shafts of the two sets of linear actuators 11 are threaded with connectors 28. The rotating rod 34 is rotatably connected between the two sets of connectors 28. The two sets of linear actuators 11 can be any of the following: cylinder, electric telescopic rod, and hydraulic rod. The extension and retraction of the extension shaft of the linear actuator 11 drives the crank 27 up and down, thereby driving the end cover 25 and the vent pipe 22 to open and close. After closing, the extension shaft of the linear actuator 11 remains extended and applies force, which can apply force to the end cover 25 and make the closing effect better. The linkage structure is rotatably connected to the drive assembly via the rotating rod 34. The linkage structure includes a third lug 26 and a crank 27. The third lug 26 is fixedly connected to the end of the end cap 25 away from the vent pipe 22. The crank 27 is rotatably connected between the rotating rod 34 and the third lug 26. The function of the crank 27 is to enable the linear motion of the extension shaft of the linear actuator 11 to drive the end cap 25 to rotate along the connection point of the first lug 23 and the second lug 24. The first sealing structure is provided on the inner wall of the connecting seat 12. The first sealing structure includes two sets of sealing rings 30. The two sets of sealing rings 30 are arranged vertically on the inner wall of the connecting seat 12. The two sets of sealing rings 30 seal between the connecting seat 12 and the outer wall of the extended shaft of the linear actuator 11, thereby sealing the buffer box 10. The second sealing structure is set between the end cap 25 and the vent pipe 22. The second sealing structure is a sealing gasket 33. The sealing gasket 33 is fixedly connected to the end of the end cap 25 facing the vent pipe 22. The sealing gasket 33 is made of refractory fiber felt. The refractory fiber felt is set at the end of the end cap 25 facing the vent pipe 22, so that the end cap 25 and the vent pipe 22 can play a sealing role when they are closed. The vacuum assembly is located at the end of the buffer box 10 away from the connecting flange 21. The vacuum assembly includes a bracket 6 and a vacuum pump group 7. The vacuum pump group 7 is fixedly connected to the end of the buffer box 10 away from the connecting flange 21 through the vacuum pipe 8. The bracket 6 is fixedly connected to the lower wall of the vacuum pump group 7. The vacuum pump group 7 draws a vacuum inside the furnace shell 2 through the vacuum pipe 8, the buffer box 10, and the vent pipe 22. The hydrogen delivery pipe 16 is fixedly connected to the rear wall of the buffer tank 10. The end of the hydrogen delivery pipe 16 away from the buffer tank 10 is fixedly connected to the hydrogen purification and delivery device. The quantitative delivery structure is set on the outer wall of the hydrogen delivery pipe 16. The quantitative delivery structure includes a pressure sensor 19, a mass flow meter 18, and a flame arrester 17. The pressure sensor 19, the mass flow meter 18, and the flame arrester 17 are fixedly connected to the outer wall of the hydrogen delivery pipe 16 in order from near to far from the buffer tank 10. After the furnace shell 2 is evacuated, the hydrogen delivered by the hydrogen purification and delivery device is sent in through the hydrogen delivery pipe 16. The input amount is controlled by the pressure sensor 19 and the mass flow meter 18. The flame arrester 17 is used to prevent backflow accidents caused by high temperature in case of accidents. The exhaust system 9 is fixedly connected to the lower wall of the buffer box 10. The exhaust system 9 is a common non-combustion hydrogen exhaust device on the market. It can treat small amounts of hydrogen without combustion, which is safer and more environmentally friendly.

[0018] Working principle: The first inner liner 13 and the second inner liner 29 are used to prevent heat from the inside of the furnace shell 2 and the buffer box 10 from spreading outwards, respectively. The third inner liner 31 and the fourth inner liner 32 are used to prevent the heat from the internal heat box and buffer box 10 from being transferred during the operation of the furnace shell 2, thus avoiding excessive heat loss. They also serve to protect the vacuum pump group 7, vacuum pipeline 8, and hydrogen delivery pipe 16. The extension and retraction of the linear actuator 11 shaft drives the crank 27 up and down, thereby opening and closing the end cover 25 and the vent pipe 22. After closing, the extension shaft of the linear actuator 11 remains extended and applies force, which can apply force to the end cover 25, making the closing effect better. The function of the crank 27 is to allow the linear movement of the extension shaft of the linear actuator 11 to drive the end cover 25 along the first lug 23 and the second lug 22. 4. When the connection point rotates, two sets of sealing rings 30 seal between the connecting seat 12 and the outer wall of the extended shaft of the linear actuator 11, which serves to seal the buffer box 10. The refractory fiber felt is placed at the end of the end cover 25 facing the vent pipe 22, so that the end cover 25 and the vent pipe 22 can be sealed when closed. The vacuum pump group 7 draws a vacuum inside the furnace shell 2 through the vacuum pipe 8, the buffer box 10, and the vent pipe 22. After the furnace shell 2 is evacuated, the hydrogen from the hydrogen purification and delivery device is sent in through the hydrogen delivery pipe 16. The input is controlled by the pressure sensor 19 and the mass flow meter 18. The flame arrester 17 is used to prevent backflow accidents caused by high temperature in case of accidents. The exhaust system 9 is a common non-combustion type exhaust device for treating hydrogen. It can treat small amounts of hydrogen without combustion, which is safer and more environmentally friendly.

[0019] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A vacuum hydrogen furnace, comprising a base frame (1), a furnace shell (2), a furnace door (4), a hydrogen purification and conveying device, and a cooling system (5), characterized in that: An explosion-proof valve (3) is provided on the upper wall of the furnace shell (2). A workbench (15) is fixedly connected to the lower inner wall of the furnace shell (2). Multiple sets of heaters (14) are provided on the inner wall of the furnace shell (2). The cooling system (5) is located on the right side of the furnace shell (2). An expansion pipe (20) is provided on the side of the furnace shell (2) away from the cooling system (5). A buffer box (10) is fixedly connected to the side of the expansion pipe (20) away from the furnace shell (2) through a connecting flange (21). The control device is used to evacuate the inside of the furnace shell (2) and fill it with hydrogen. The control device includes: Vent pipe (22), the vent pipe (22) is fixedly connected to the side of the connecting flange (21) away from the expansion pipe (20) and located inside the buffer box (10); An end cap (25) used to separate the interior of the furnace shell (2) from the buffer box (10) during furnace shell (2) operation. The end cap (25) is rotatably connected to the end of the vent pipe (22) away from the connecting flange (21) by a first lug (23), a second lug (24) and a pivot pin. A drive assembly for closing the end cap (25) is fixedly connected to the upper wall of the buffer box (10) by two sets of connecting seats (12); A linkage structure for transmission is provided between the drive assembly and the end cap (25), the linkage structure being rotatably connected to the drive assembly via a rotating rod (34); A first sealing structure for sealing the connection seat (12) and the drive assembly is disposed on the inner sidewall of the connection seat (12); A second sealing structure is provided between the end cap (25) and the vent pipe (22) for sealing the space between the end cap (25) and the vent pipe (22); The heat insulation structure is provided on the inner wall of the furnace shell (2), the vent pipe (22), the end cover (25) and the buffer box (10); A vacuum assembly is disposed at the end of the buffer box (10) away from the connecting flange (21); A hydrogen delivery pipe (16) for transporting hydrogen is fixedly connected to the rear wall of the buffer tank (10), and the end of the hydrogen delivery pipe (16) away from the buffer tank (10) is fixedly connected to the hydrogen purification and delivery device. A quantitative delivery structure for controlling the precise delivery of hydrogen is provided on the outer wall of the hydrogen delivery pipe (16); An exhaust system (9) for exhausting air after the operation is completed, the exhaust system (9) being fixedly connected to the lower wall of the buffer box (10).

2. The vacuum hydrogen furnace according to claim 1, characterized in that: The drive assembly includes two sets of linear actuators (11). The two sets of linear actuators (11) are respectively fixedly connected to the upper wall of the buffer box (10) in a front-to-back manner through a set of connecting seats (12). The extension shaft of the linear actuator (11) passes through the inner wall of the connecting seat (12) and the upper wall of the buffer box (10) and extends into the interior of the buffer box (10). The ends of the extension shafts of the two sets of linear actuators (11) are threaded with connectors (28). The rotating rod (34) is rotatably connected between the two sets of connectors (28).

3. A vacuum hydrogen furnace according to claim 2, characterized in that: The linkage structure includes a third lug (26) and a crank (27). The third lug (26) is fixedly connected to the end of the end cap (25) away from the vent pipe (22), and the crank (27) is rotatably connected between the rotating rod (34) and the third lug (26).

4. A vacuum hydrogen furnace according to claim 3, characterized in that: The first sealing structure includes two sets of sealing rings (30), which are arranged vertically on the inner sidewall of the connecting seat (12).

5. A vacuum hydrogen furnace according to claim 4, characterized in that: The second sealing structure is a sealing gasket (33), which is fixedly connected to one end of the end cap (25) facing the vent pipe (22). The sealing gasket (33) is made of fire-resistant fiber felt.

6. A vacuum hydrogen furnace according to claim 5, characterized in that: The heat insulation structure includes a first inner liner (13), a second inner liner (29), a third inner liner (31), and a fourth inner liner (32). The first inner liner (13) is disposed on the inner wall of the furnace shell (2), the second inner liner (29) is disposed on the inner wall of the buffer box (10), the third inner liner (31) is disposed on the inner wall of the vent pipe (22), and the fourth inner liner (32) is disposed on the inner wall of the end cap (25) and located between the end cap (25) and the second sealing structure.

7. A vacuum hydrogen furnace according to claim 6, characterized in that: The vacuum assembly includes a bracket (6) and a vacuum pump group (7). The vacuum pump group (7) is fixedly connected to the end of the buffer box (10) away from the connecting flange (21) through a vacuum pipe (8). The bracket (6) is fixedly connected to the lower wall of the vacuum pump group (7).

8. A vacuum hydrogen furnace according to claim 7, characterized in that: The quantitative delivery structure includes a pressure sensor (19), a mass flow meter (18), and a flame arrester (17). The pressure sensor (19), mass flow meter (18), and flame arrester (17) are fixedly connected to the outer wall of the hydrogen delivery pipe (16) in order from near to far from the buffer tank (10).

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