Air duct structure for vacuum furnace rapid cooling

Abstract

The application relates to a wind channel structure for vacuum furnace fast cooling, which comprises a wind collecting box arranged on one side of a hot field frame and communicated with an air inlet of a furnace body and a plurality of air pipes communicated with the wind collecting box, the air pipes are arranged at intervals along the axis direction of the hot field, and each air pipe is annularly sleeved outside the hot field frame; a first air supply hole is arranged on the side of each air pipe close to the hot field frame, the first air supply hole is arranged at intervals around the circumferential direction of the air pipe, a plurality of second air supply holes are arranged on the side of the wind collecting box close to the hot field frame, and air inlets corresponding to the first air supply holes and the second air supply holes are arranged on the hot field frame. The application has the effects that the Ar gas flow is guided by the wind collecting box and the air pipe, the probability of turbulent flow and heat energy loss is reduced, the Ar gas flow is uniformly diffused in the wind collecting box and the air pipe and permeates into each position of the hot field, the temperature of each position in the hot field is uniformly reduced, and the performance of a workpiece is improved.

Description

Technical Field

[0001] This application relates to the technical field of vacuum furnaces, and in particular to an air duct structure for rapid cooling in vacuum furnaces. Background Technology

[0002] For the vacuum heat treatment industry, the most important factors are furnace temperature and achieving vacuum. Another crucial parameter, directly impacting the customer's firing efficiency and workpiece surface properties, is the rapid cooling time.

[0003] Rapid cooling refers to the method of quickly cooling a workpiece after the heating process is completed, usually by using a gas or liquid medium to carry away the heat. For heat treatment furnaces, rapid cooling is generally achieved by introducing an Ar gas flow into a vacuum furnace.

[0004] Horizontal vacuum heat treatment furnaces come in various forms. Based on whether the fan impeller is inside the furnace, they are classified as internal circulation rapid cooling or external circulation rapid cooling; and based on the position of the air inlet relative to the furnace body, they are classified as rear air inlet or side air inlet. Conventional vacuum heat treatment furnaces use an external circulation rear air inlet structure, where the fan impeller is connected to the furnace body's air inlet via a pipe to blow Ar gas into the furnace body. However, when the presence of a rear gate valve or other components prevents rear air inlet, a side air inlet structure is required.

[0005] For a horizontal vacuum processing furnace with side air intake, the furnace body and the main body of the reflector assembly (hereinafter referred to as the hot zone) located inside the furnace body are included. The interior of the hot zone forms a heating chamber for heating the material, and several air nozzles are evenly distributed on the side wall of the hot zone. The Ar gas flow entering the furnace body is forced into the air nozzles under the action of air pressure. However, because the Ar gas flow diffuses randomly in all directions after entering the area between the furnace body and the hot zone, it causes severe turbulence, significant kinetic energy loss and conversion into heat energy. This will reduce the air volume entering the heating chamber, increase the total rapid cooling time, and reduce the rapid cooling efficiency. If the rapid cooling efficiency requirement is to be met, the air volume and air pressure of the fan impeller need to be increased, which will lead to increased energy consumption. Summary of the Invention

[0006] In order to reduce the kinetic energy loss after Ar gas flows into the furnace body and shorten the total cooling time, and to ensure that the Ar gas flow completes circulation more evenly, thereby ensuring that the temperature at each position in the hot zone decreases evenly and improving the performance of the workpiece, this application provides a duct structure for rapid cooling in a vacuum furnace.

[0007] The air duct structure for rapid cooling in a vacuum furnace provided in this application adopts the following technical solution:

[0008] A duct structure for rapid cooling of a vacuum furnace includes an air collection box disposed on one side of a hot zone frame and connected to the air inlet of the furnace body, and a plurality of air ducts connected to the air collection box. The plurality of air ducts are spaced apart along the axial direction of the hot zone, and each air duct is arranged in a ring around the outside of the hot zone frame.

[0009] Each of the air ducts has a first air supply hole on the side near the thermal field frame. There are several first air supply holes, which are spaced apart around the circumference of the air duct. The air collection box has several second air supply holes on the side near the thermal field frame. The thermal field frame has air inlets corresponding to the first air supply holes and the second air supply holes.

[0010] By adopting the above technical solution, during rapid cooling of the workpiece, the Ar airflow introduced from the air inlet is directly introduced into the air collection box, reducing the probability of uneven diffusion of the Ar airflow in the area between the furnace body and the hot zone, which would lead to turbulence. This reduces heat loss during the Ar airflow flow, increases the overall air volume entering the hot zone, and reduces the total rapid cooling time. The Ar airflow entering the air collection box diffuses evenly in four directions: up, down, left, and right. Some of the Ar airflow is directly blown into the hot zone from the second air outlet, while the rest diffuses into the various air ducts and gradually enters the hot zone under the guidance of the air ducts. By guiding the Ar airflow through the air ducts, and with several air ducts spaced apart and the first air outlets on the air ducts also evenly distributed, the Ar airflow can diffuse to all positions within the hot zone, resulting in a uniform temperature reduction at all positions within the hot zone and improving the workpiece performance.

[0011] Preferably, each of the air ducts includes an upper air duct fixed to the upper side of the thermal field frame and a lower air duct fixed to the lower side of the thermal field frame. One end of the upper air duct and the lower air duct are connected to the air collection box, and the other end is closed. The upper air duct and the lower air duct are symmetrically arranged.

[0012] By adopting the above technical solution, the air duct is divided into an upper air duct and a lower air duct, which allows the air duct to enter from both the upper and lower sides at the same time, improving the rapid cooling efficiency. At the same time, the other ends of the upper air duct and the lower air duct are not connected, which avoids the Ar airflow entering the air duct from circulating in the upper and lower air ducts, thus preventing the air intake efficiency from decreasing.

[0013] Preferably, the air collecting box has an air collecting port located at the center of the air collecting box and connected to the air inlet of the furnace body via an air inlet pipe.

[0014] By adopting the above technical solution, the uniformity of Ar gas flow within the thermal field is improved.

[0015] Preferably, the second air supply holes are evenly distributed on the air collection box, and the second air supply holes are arranged in a one-to-one correspondence with the first air supply holes located on the opposite side of the air collection box.

[0016] By adopting the above technical solution, the uniformity of airflow on both sides of the hot zone can be improved, resulting in uniform temperature on both sides of the hot zone.

[0017] Preferably, the upper air duct and the lower air duct in each of the air ducts are located in the same vertical section and are symmetrically arranged, and the first air supply holes on the upper and lower sides are arranged in a one-to-one correspondence.

[0018] By adopting the above technical solution, the uniformity of airflow on both the upper and lower sides of the thermal field is improved, resulting in uniform temperature on both the upper and lower sides of the thermal field.

[0019] Preferably, the number of first air supply holes on both the upper and lower air ducts is set to 3 to 5, wherein the number of first air supply holes on the upper and lower sides is 2 to 4, and the number of first air supply holes on the side away from the air collection box is 1.

[0020] By adopting the above technical solution, generally speaking, the more air inlets there are, the more uniform the airflow and temperature will be throughout the hot zone. However, the more air inlets there are, the worse the thermal insulation performance of the hot zone will be. Taking an example with 8-12 air inlets in the same vertical section without affecting the thermal insulation performance, this approach ensures that the airflow on the top and bottom sides is uniform with that on the left and right sides, improving the uniformity of airflow throughout the hot zone, resulting in a more uniform temperature reduction and improved workpiece performance.

[0021] Preferably, each of the air inlets is rotatably provided with an adjustment seat between itself and the first air outlet and the second air outlet. The adjustment seat is used to adjust the air intake of each air inlet so that the air intake of the front, middle and rear areas is uniform.

[0022] The adjusting seat is a hollow cylindrical structure with one end sealed. An adjusting hole is provided on the end face of the sealed end of the adjusting seat. The axis of the adjusting hole coincides with the axis of the adjusting seat. The adjusting hole is a fan shape with two opposing axes. The shapes of the first air supply hole and the second air supply hole are consistent with the shape of the adjusting hole.

[0023] By adopting the above technical solution, when the adjustment hole and the first air supply hole are aligned, the air inlet is at its maximum air intake, and all the airflow through the first air inlet hole can enter the air inlet hole. When it is necessary to adjust the air intake of the front, middle and rear zones of the hot zone to be consistent, by rotating the adjustment seat, the adjustment hole partially blocks the first air supply hole, and as the adjustment seat continues to rotate, the airflow entering the air inlet hole gradually decreases. This allows for targeted adjustment of the airflow at each location, improving the temperature uniformity of each location within the hot zone.

[0024] Preferably, each of the air inlets is fitted with a nozzle, one end of which extends into the heating chamber. Each nozzle is also fitted with a sleeve to reduce contamination of the heating chamber by the main body of the reflector assembly, and the nozzle and the sleeve are detachably connected.

[0025] By adopting the above technical solution, one end of the nozzle extends into the interior of the hot zone, which facilitates the smooth introduction of Ar airflow into the interior of the hot zone. By sleeved the nozzle on the outside of the nozzle and the adjustment seat, the contamination of the heating chamber by the hot zone material can be reduced.

[0026] Preferably, a front reflector assembly and a rear reflector assembly are respectively provided on the front and rear sides of the hot field, and gaps are left between the front reflector assembly, the rear reflector assembly and the hot field to form a return air channel for return air.

[0027] By adopting the above technical solution, the Ar airflow entering the heating chamber diffuses towards both ends, gradually carrying away the heat from the workpiece. Upon reaching the end of the heating chamber, it flows out through the return air channel and returns to the fan impeller via the return air duct on the furnace body, thus achieving a complete rapid cooling cycle. By providing return air channels at both ends of the heating chamber, compared to the traditional method of providing a return air channel at only one end, the Ar airflow recovery efficiency is increased, and the overall rapid cooling time is shortened.

[0028] Preferably, the sum of the circumferential areas of the two return air channels is equal to the area of ​​the air inlet.

[0029] By adopting the above technical solution, the air intake and return volume of the furnace body are kept uniform and consistent, thus accelerating the rapid cooling cycle.

[0030] In summary, this application includes at least one of the following beneficial technical effects:

[0031] 1. This application, by setting up an air collecting box connected to the air inlet and several air ducts connected to the air collecting box and spaced apart along the axis of the hot zone, facilitates the guidance of the Ar gas flow entering the furnace body, so that the Ar gas flow is evenly diffused in the air collecting box and air ducts, reducing the turbulence caused by the irregular diffusion of the Ar gas flow, reducing the kinetic energy loss of the Ar gas flow, increasing the overall air volume inside the hot zone, shortening the total rapid cooling time and improving the rapid cooling efficiency; and by setting the air ducts spaced apart along the axis of the hot zone, and the first air outlet on the air duct is also spaced apart along the circumferential direction of the air duct, the Ar gas flow can be fully diffused to all positions in the hot zone, so that the temperature in all positions in the hot zone is reduced evenly, improving the performance of the workpiece.

[0032] 2. The air intake volume of each air inlet can be adjusted by adjusting the setting of the air inlet. By adjusting the direct blowing position of the air collector and the air intake volume at both ends of the air collector, the temperature of the front, middle and rear zones can be made as uniform as possible, thereby improving the rapid cooling efficiency and workpiece performance.

[0033] 3. By setting return air channels at both ends of the hot zone, a side air intake combined with return air at both ends is formed, which increases the return air efficiency and accelerates the overall rapid cooling cycle; it allows the Ar airflow entering the heating chamber to more effectively remove more heat, minimizes the useless work of the Ar airflow in the rear zone, and has a higher rapid cooling efficiency. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the air duct structure of this application installed on the thermal field frame.

[0035] Figure 2 This is a cross-sectional schematic diagram of this application.

[0036] Figure 3 This is a structural diagram of the air collection box made to show the arrangement of the first air supply vents.

[0037] Figure 4 This is a schematic diagram of the upper air duct structure.

[0038] Figure 5 yes Figure 2 A magnified view of a portion of point A in the middle.

[0039] Figure 6 This is a schematic diagram of the adjustment seat.

[0040] Figure 7 This is a top view of the overall structure created to show the location of the return air duct.

[0041] Explanation of reference numerals in the attached drawings: 01, Hot zone; 011, Hot zone frame; 012, Heating chamber; 013, Air inlet; 02, Front reflector assembly; 03, Rear reflector assembly; 1, Air collection box; 11, Second air supply hole; 12, Air collection port; 2, Air duct; 21, First air supply hole; 22, Upper air duct; 23, Lower air duct; 3, Adjustment seat; 31, Rotating base; 32, Adjustment top seat; 321, Adjustment hole; 322, Connection hole; 323, Wrench hole; 4, Screw; 5, Nut; 6, Nozzle; 7, Sleeve; 8, Pin; 9, Return air channel. Detailed Implementation

[0042] The following is in conjunction with the appendix Figure 1-7 This application will be described in further detail.

[0043] This application discloses an air duct structure for rapid cooling in a vacuum furnace. (Refer to...) Figure 1 The air duct structure for rapid cooling of the vacuum furnace includes an air collection box 1 located on one side of the hot field frame 011 and connected to the furnace air inlet (not shown in the figure), and several air ducts 2 connected to the air collection box 1. The several air ducts 2 are spaced apart along the axial direction of the hot field 01, and each air duct 2 is enclosed in a ring shape outside the hot field frame 011.

[0044] Reference Figure 1 and Figure 2 Each air duct 2 has a first air supply hole 21 on the side near the thermal field frame 011. Several first air supply holes 21 are provided and spaced apart around the circumference of the air duct 2. The air collection box 1 has several second air supply holes 11 on the side near the thermal field frame 011. The thermal field frame 011 has several air inlets 013 corresponding to the first air supply holes 21 and the second air supply holes 11. Ar gas flow enters directly into the air collection box 1 after entering the furnace body through the air inlet, and gradually diffuses towards both ends of the air collection box 1. Part of the Ar gas flow directly enters the interior of the thermal field 01 through the second air supply holes 11, while another part of the Ar gas flow enters the interior of each air duct 2 and then enters the interior of the thermal field 01 through the first air supply holes 21. (Refer to...) Figure 3An air collecting box 1 has an air collecting port 12, which is connected to the air inlet of the furnace body via an air inlet pipe (not shown in the figure). By setting up the air collecting box 1 and connecting it to the air inlet of the furnace body, the Ar airflow, after entering the area between the interior of the furnace body and the exterior of the hot zone 01, can only flow in a predetermined direction and enter the air collecting box 1. Inside the air collecting box 1, the airflow gradually diffuses and is guided by several air ducts 2, allowing the Ar airflow to fully diffuse into the front, middle, and rear areas of the heating chamber 012 along the axial direction of the hot zone 01. Along the axial direction perpendicular to the hot zone 01, the Ar airflow can diffuse to the upper, lower, left, and right sides of the heating chamber 012. Compared to the traditional method of directly introducing Ar gas into the furnace body, this method not only reduces the probability of irregular diffusion of Ar gas in the area between the furnace body and the hot zone 01, which leads to turbulence in the Ar gas flow, but also reduces the kinetic energy loss of the Ar gas flow and increases the overall air volume entering the hot zone 01; at the same time, it makes the air velocity more uniform in various positions inside the hot zone 01, thus improving the performance of the workpiece.

[0045] Reference Figure 2 and Figure 4 To increase the flow velocity of Ar gas within the duct 2, both ends of the duct 2 are connected to the upper and lower ends of the air collection box 1. This means that Ar gas can simultaneously enter the duct 2 from both the top and bottom of the air collection box 1. To further reduce the probability of Ar gas circulating within the duct 2 after entering, thus decreasing air intake efficiency, the duct 2 includes an upper duct 22 welded to the upper side of the thermal field frame 011 and a lower duct 23 welded to the lower side of the thermal field frame 011. Both the upper duct 22 and the lower duct 23 are connected to the air collection box 1 at one end and closed at the end away from the air collection box 1. In this application, the example of both the upper duct 22 and the lower duct 23 being flange-connected to the air collection box 1 will be used for illustration.

[0046] Reference Figure 2 and Figure 3 To improve the uniformity of Ar airflow diffusion, the air inlet 12 is located at the center of the air collection box 1. Furthermore, second air outlets 11 are evenly distributed on the air collection box 1, and each second air outlet 11 corresponds one-to-one with the first air outlet 21 located on the opposite side of the air collection box 1, so that the Ar airflow entering the left and right sides of the heating chamber 012 is as uniform as possible. Even further, the upper air duct 22 and the lower air duct 23 in each air duct 2 are located within the same vertical cross-section. In this application, the upper air duct 22 and the lower air duct 23 have completely identical structures; the symmetrical installation during installation is used as an example for illustration. At this time, the first air outlets 21 located on the upper and lower sides are arranged one-to-one to ensure that the Ar airflow entering the upper and lower sides of the heating field 01 is as uniform as possible.

[0047] Reference Figure 2Generally, the number of air inlets 013 on the thermal field frame 011 can be arbitrarily set. When the air inlets 013 are evenly distributed, the air velocity entering the thermal field 01 becomes more uniform as the number of air inlets 013 increases. However, this also leads to a decrease in the thermal insulation performance of the thermal field 01. In order to balance the thermal insulation performance and the uniformity of airflow, after several wind speed and thermal insulation tests, this application sets five air ducts 2 at intervals along the axial direction of the thermal field 01. The number of first air supply holes 21 on each upper air duct 22 and lower air duct 23 is set to 3 to 5. Among them, the number of first air supply holes 21 located on the upper and lower sides is 2 to 4, and the number of first air supply holes 21 located on the side away from the air collection box 1 is 1. That is, in the same vertical section, the number of second air supply holes 11 and the number of first air supply holes 21 located on the side away from the air collection box 1 are both set to 2. This is to keep the Ar airflow in the vertical and horizontal directions inside the thermal field 01 as uniform as possible. This application uses the example of having 10 air inlets 013 and 3 first air outlets 21 on both the upper and lower sides within the same vertical cross section for illustration.

[0048] Reference Figure 5 and Figure 6 Each air inlet 013 and the first air outlet 21 and the second air outlet 11 is rotatably provided with an adjustment seat 3 for adjusting the air intake volume of the air inlet 013.

[0049] Reference Figure 5 and Figure 6 Specifically, the adjusting seat 3 is a hollow cylindrical structure with one end sealed. An adjusting hole 321 is provided on the end face of the sealed end of the adjusting seat 3. The axis of the adjusting hole 321 coincides with the axis of the adjusting seat 3. The shapes of the first air supply hole 21 and the second air supply hole 11 are consistent with the shape of the adjusting hole 321. The shape of the adjusting hole 321 is arbitrary and not a perfect circle. In order to achieve the effect of gradually decreasing or increasing the air intake, this application takes the design of the adjusting hole 321 as a fan shape with two opposite apexes as an example for explanation.

[0050] Reference Figure 5 and Figure 6 The adjusting seat 3 is connected to the air duct 2 and the air collection box 1 by screws 4. A connecting hole 322 for engaging with the screw 4 is also provided on the end face of the sealed end of the adjusting seat 3. The connecting hole 322 is located at the axial center of the adjusting seat 3 and coincides with the axial center of the two adjusting holes 321. Nuts 5 are provided at corresponding positions of the first air supply hole 21 and the second air supply hole 11. By passing the screw 4 through the connecting hole 322 and threading it with the nut 5, the adjusting seat 3 can be fixed.

[0051] Taking the airflow adjustment at the first air outlet 21 as an example, when the two adjustment holes 321 are aligned with the fan-shaped shape of the first air outlet 21, the first air outlet 21 is at its maximum opening, and the airflow entering the hot zone 01 is at its maximum. During adjustment, the worker loosens the screw 4 connecting the adjustment seat 3 and the air duct 2 from inside the hot zone 01, and rotates the adjustment seat 3 clockwise or counterclockwise so that the adjustment hole 321 coincides with the fan-shaped structure of the first air outlet 21, thereby gradually reducing the opening of the first air outlet 21 and reducing the airflow into the air inlet 013.

[0052] By setting the adjustment seat 3, the air intake volume at various locations within the hot zone 01 is adjustable, i.e., the wind speed is adjustable. This allows for wind speed adjustment based on the measured wind speed relationships between the front, middle, and rear zones of the hot zone 01, resulting in more uniform wind speeds throughout the hot zone 01. Generally, for the side-inlet horizontal vacuum heat treatment furnace of this application, since the Ar gas flow diffuses evenly from the middle of the air collection box 1 to both ends, the area directly blown by the air collection port 12 (referred to as the front zone) has the largest air volume, the area located at both ends of the air collection port 12 and closer to it (referred to as the middle zone) has the second largest air volume, and the area located at both ends of the air collection port 12 and farther away from it (referred to as the rear zone) has the smallest air volume. Therefore, this application adjusts the air intake volume of the front zone, middle zone and rear zone. When adjusting, the adjustment should meet the rule of 1.1V (rear zone) ≈ V (middle zone) ≈ 1.2V (front zone) to ensure that the temperature T (rear zone) = T (middle zone) = T (front zone) as much as possible, so as to make the air velocity of the front zone, middle zone and rear zone uniform.

[0053] Reference Figure 5 and Figure 6 To achieve a wider airflow adjustment range, the adjusting seat 3 includes a rotating base 31 that extends into the air inlet 013 and an adjusting top seat 32 integrally formed on one side of the rotating base 31 and communicating with the interior of the rotating base 31. The top surface of the adjusting top seat 32 is sealed, and both the connecting hole 322 and the adjusting hole 321 are located on the top surface of the adjusting top seat 32. The diameter of the adjusting top seat 32 is larger than the diameter of the rotating base 31, which allows each adjusting hole 321 to have a larger area, thereby increasing the adjustment range of the first air outlet 21 and the second air outlet 11.

[0054] Reference Figure 5 and Figure 6 To facilitate the tightening of the adjusting seat 3, two wrench holes 323 are provided on the top surface of the adjusting top seat 32. The two wrench holes 323 are located on both sides of the connecting hole 322 and are both located in the space between the two adjusting holes 321. After loosening the bolt, a double-leg wrench can be inserted into the two wrench holes 323 to quickly rotate the adjusting seat 3.

[0055] Reference Figure 5A nozzle 6 is inserted inside each air outlet. The nozzle 6 is located at the rear of the adjustment base 3, with the end of the nozzle 6 furthest from the adjustment base 3 extending into the heating chamber 012. This is to better guide the Ar airflow into the heating chamber 012 and reduce contamination of the heating chamber 012 by the aluminum silicate cotton reflector assembly. To reduce the probability of the nozzle 6 deforming over time, this application uses a ceramic material for the nozzle 6 as an example. Furthermore, a sleeve 7 is fitted over the outside of each nozzle 6. The sleeve 7 is used to further reduce contamination of the heating chamber 012 by the aluminum silicate cotton reflector assembly. The nozzle 6 and the sleeve 7 are detachably connected for easy replacement when the nozzle 6 deforms. This application uses a pin 8 to prevent the part of the nozzle 6 extending into the heating chamber 012 from being fixed to the sleeve 7 for anti-rotation.

[0056] Reference Figure 7 A front reflector assembly 02 and a rear reflector assembly 03 are respectively provided on the front and rear sides of the hot zone 01. The front reflector assembly 02 and the rear reflector assembly 03 are connected to the interior of the hot zone 01 and a certain gap is left between them to form a return air channel 9 for return air. Specifically, for the side-inlet type vacuum heat treatment furnace of this application, the side of the front reflector assembly 02 facing away from the hot zone 01 is fixed to the front furnace door, and the bottom of the front reflector assembly is fixed to the furnace body by a hinge; the side of the rear reflector assembly 03 facing away from the hot zone 01 is fixed to the slide valve, and the bottom of the rear reflector assembly 03 is fixed to the furnace body by a hinge to obtain the return air channel 9.

[0057] The Ar airflow entering the heating chamber 012 diffuses towards both ends, gradually carrying away the heat from the workpiece. Upon reaching the end of the heating chamber 012, it flows out through the return air channel 9 and returns to the fan impeller via two return air pipes on the furnace body, thus completing a full rapid cooling cycle. By providing return air channels 9 at both ends of the heating chamber 012, compared to the traditional method of providing a return air channel 9 at only one end, the return air efficiency of the Ar airflow is increased, and the overall rapid cooling time is shortened.

[0058] In traditional rear-entry airflow systems, the front zone has the highest airflow velocity, and the return air is also located in the front zone. The Ar airflow, having just reached the front zone, exits through the return air location before it has had time to carry away heat, resulting in wasted Ar airflow and low rapid cooling efficiency. This application addresses this by designing the airflow structure and placing the return air channel 9 at the very front and rear of the heating chamber 012. This minimizes the airflow velocity of the Ar airflow entering the rear zone near the return air channel 9, allowing it to more effectively carry away more heat and reducing wasted Ar airflow in the rear zone, thus achieving higher rapid cooling efficiency. Simultaneously, this arrangement of the return air channel 9 provides a longer flow path for the Ar airflow entering the front and middle zones, allowing for better heat removal from the workpiece, shortening the overall rapid cooling time, and improving rapid cooling efficiency.

[0059] Furthermore, in order to keep the air intake and return volume of the furnace body uniform and consistent, the total area of ​​the two return air channels 9 in the circumferential direction is set to be equal to the area of ​​the air inlet 12. This application takes the example that the width of each return air channel 9 is 10~15mm.

[0060] In conventional methods to improve rapid cooling efficiency, the power of the fan motor (not shown in the diagram) is generally increased to provide greater airflow and pressure. However, this also increases the energy consumption of rapid cooling. To achieve higher airflow and pressure without increasing or with minimal energy consumption, and thus improve rapid cooling efficiency, the impeller diameter can be increased to obtain a larger flow rate. However, the larger the impeller flow rate, the lower the total pressure (i.e., lower air pressure) will be if the power remains unchanged. Different duct systems have different optimal flow rates and total pressures; even slight changes in the duct structure will alter the corresponding optimal impeller flow rate and total pressure. Therefore, by rationally designing the impeller structure to better match these parameters, the total airflow can be increased without increasing or with minimal energy consumption, thereby reducing rapid cooling time and increasing rapid cooling efficiency.

[0061] The implementation principle of the air duct structure for rapid cooling of a vacuum furnace according to an embodiment of this application is as follows: During cooling, the fan impeller blows Ar airflow directly from the air inlet of the furnace body into the air collection box 1 along the air inlet pipe, and diffuses it evenly within the air collection box 1. This allows part of the Ar airflow to be directly blown into the interior of the hot zone 01 from the second air outlet 11, while the remaining Ar airflow diffuses to and enters each of the upper air ducts 22 and each of the lower air ducts 23. Under the guiding effect of the upper air ducts 22 and the lower air ducts 23, it gradually enters the interior of the hot zone 01 from the positions of several first air outlets 21. By connecting the air collection port 12 and the air inlet, and planning a specific direction of movement for the Ar airflow, the probability of kinetic energy loss due to turbulence in the Ar airflow entering the furnace body, leading to a decrease in rapid cooling efficiency, is reduced. Furthermore, by setting the number of air inlets 013 on the left and right sides of the hot zone 01 to be the same, and the number of air inlets 013 on the top and bottom sides to be the same, and maintaining uniformity in the number of air inlets 013 on the left and right sides and the top and bottom sides, the airflow in the four directions (up, down, left, right) inside the hot zone 01 is made uniform, thus improving workpiece performance. Since the airflow is greatest in the area directly blowing from the air collector 12, the airflow gradually decreases in the areas on both sides of the air collector 12. By adjusting the airflow of the air inlets 013 in the front, middle, and rear zones of the hot zone 01, the airflow velocity in the front, middle, and rear zones is made uniform, thus causing the temperature inside the hot zone 01 to decrease uniformly, thereby improving workpiece performance.

[0062] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A duct structure for rapid cooling in a vacuum furnace, characterized in that: It includes an air collection box (1) located on one side of the hot field frame (011) and connected to the air inlet of the furnace body, and several air ducts (2) connected to the air collection box (1). The several air ducts (2) are spaced apart along the axial direction of the hot field (01), and each air duct (2) is enclosed in a ring around the outside of the hot field frame (011). Each of the air ducts (2) has a first air supply hole (21) on the side near the thermal field frame (011). There are a plurality of first air supply holes (21) and they are spaced apart around the circumferential direction of the air duct (2). The air collection box (1) has a plurality of second air supply holes (11) on the side near the thermal field frame (011). The thermal field frame (011) has air inlets (013) corresponding to the first air supply holes (21) and the second air supply holes (11). Each of the air inlets (013) is rotatably provided with an adjustment seat (3) between itself and the first air outlet (21) and the second air outlet (11). The adjustment seat (3) is used to adjust the air intake of each of the air inlets (013) so that the air intake of the front, middle and rear areas is uniform. The adjusting seat (3) is a cylindrical structure with a hollow interior and one end sealed. An adjusting hole (321) is provided on the end face of the sealed end of the adjusting seat (3). The axis of the adjusting hole (321) coincides with the axis of the adjusting seat (3). The adjusting hole (321) is a fan shape with two axes facing each other. The shapes of the first air supply hole (21) and the second air supply hole (11) are consistent with the shape of the adjusting hole (321). The adjusting seat (3) is coaxially provided with a connecting hole (322), and a screw (4) is provided through the connecting hole (322). Nuts (5) that are threadedly connected to the screw (4) are provided on the first air supply hole (21) and the second air supply hole (11). An air collection port (12) is provided on the air collection box (1). The air collection port (12) is located in the center of the air collection box (1) and is connected to the air inlet of the furnace body through an air inlet pipe. The front and rear sides of the hot field (01) are respectively provided with a front reflector assembly (02) and a rear reflector assembly (03). There are gaps between the front reflector assembly (02), the rear reflector assembly (03) and the hot field (01) to form a return air channel (9) for return air. The total area of ​​the two return air channels (9) in the circumferential direction is equal to the area of ​​the air inlet (12).

2. The air duct structure for rapid cooling of a vacuum furnace according to claim 1, characterized in that: Each of the aforementioned air ducts (2) includes an upper air duct (22) fixed on the upper side of the thermal field frame (011) and a lower air duct (23) fixed on the lower side of the thermal field frame (011). The upper air duct (22) and the lower air duct (23) are connected to the air collection box (1) at one end and closed at the other end. The upper air duct (22) and the lower air duct (23) are symmetrically arranged.

3. The air duct structure for rapid cooling of a vacuum furnace according to claim 1, characterized in that: The second air supply hole (11) is evenly arranged on the air collection box (1), and the second air supply hole (11) is arranged in a one-to-one correspondence with the first air supply hole (21) located on the opposite side of the air collection box (1).

4. The air duct structure for rapid cooling of a vacuum furnace according to claim 2, characterized in that: The upper air duct (22) and the lower air duct (23) in each of the air ducts (2) are located in the same vertical section and are symmetrically arranged, and the first air supply holes (21) on the upper and lower sides are arranged in a one-to-one correspondence.

5. The air duct structure for rapid cooling of a vacuum furnace according to claim 4, characterized in that: The number of the first air supply holes (21) on the upper air duct (22) and the lower air duct (23) is set to 3 to 5, and one first air supply hole (21) is provided on the side opposite to the air collection box (1).

6. The air duct structure for rapid cooling of a vacuum furnace according to claim 1, characterized in that: Each of the air inlets (013) is equipped with a nozzle (6), one end of which extends into the heating chamber (012). Each of the air inlets (6) is also fitted with a sleeve (7) to reduce the contamination of the heating chamber (012) by the material of the thermal field (01), and the air inlets (6) and the sleeve (7) are detachably connected.

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