High-temperature automatic tube furnace

Abstract

The utility model provides a high-temperature automatic tube furnace which comprises a base, driving assemblies, a heating assembly, a placing assembly and a vacuum pipe fitting, the driving assemblies are fixed to the front side and the rear side of the upper end of the base, and the heating assembly is fixed to the middle of the upper end of the base. Compared with the prior art, the device has the following beneficial effects that by arranging the base, the driving assembly and the containing assembly, the whole device is high in automation degree, for experiments needing to frequently use equipment to heat objects, the efficiency of the heating experiments can be effectively improved, meanwhile, the labor intensity of operators is reduced, and the three rotary air cylinders distributed in a trisection structure are arranged, so that the working efficiency is improved. The sealing plate can be spun and locked when necessary, so that the sealing plate tightly abuts against the right end face of the alundum tube, the vacuum degree in the alundum tube is further ensured, the stability of vacuum heating is improved, and it is ensured that a vacuum heating experiment is conducted stably.

Description

Technical Field

[0001] The present invention belongs to the technical field of tube furnaces, and particularly relates to a high-temperature automatic tube furnace. Background Art

[0002] Existing high-temperature tube furnaces have several drawbacks in terms of low automation level, which affect their operation efficiency and usage effect. First of all, high-temperature tube furnaces with low automation level require a large amount of manual intervention, including temperature adjustment, material feeding and discharging, maintenance and other links. This not only increases the workload of operators, but also raises the risk of human operation errors, making it difficult to precisely control process parameters and affecting product quality. Secondly, due to the lack of an automatic monitoring and adjustment system, high-temperature tube furnaces cannot monitor temperature and other key parameters in real time during operation, cannot detect and adjust abnormal situations in a timely manner, and may lead to problems such as equipment overheating and material damage. The emergence of these drawbacks is mainly due to the technical limitations in the design of high-temperature tube furnaces, the lack of advanced sensors and automatic control systems, as well as the relatively high cost of automation technology, which results in insufficient investment by some enterprises in equipment upgrading.

[0003] To address these problems, conventional methods include: increasing the frequency of manual inspections and monitoring, and ensuring the normal operation and temperature control of the equipment through regular inspections and manual adjustments; introducing simple auxiliary equipment, such as manual thermometers and control valves, to assist in temperature adjustment and monitoring. However, these methods also have obvious drawbacks. Increasing manual monitoring can alleviate the problem of low equipment automation level to a certain extent, but cannot completely solve the problems of low operation efficiency and human errors; although the cost of introducing auxiliary equipment is relatively low, its accuracy and response speed are far less than those of an automatic system, and additional manual operation and maintenance are required. In addition, manual monitoring and simple auxiliary equipment are unable to cope with complex process requirements and large-scale production, and are difficult to meet the production requirements of high precision and high efficiency. Therefore, we hope to design a tube furnace with a new structure to solve this problem. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a high-temperature automatic tube furnace to solve the problems raised in the above background art.

[0005] The present invention is realized through the following technical solutions: a high-temperature automatic tube furnace, comprising: a base, a driving assembly, a heating assembly, a placement assembly, and a vacuum pipe fitting. The driving assembly is fixed to the front side and the rear side of the upper end of the base, and the heating assembly is fixed to the middle of the upper end of the base;

[0006] The vacuum pipe fitting is installed inside the heating assembly, the placement assembly is movably installed at the right end of the driving assembly, and a part of the left end of the placement assembly is movably installed inside the right end of the vacuum pipe fitting through the driving assembly.

[0007] As a preferred embodiment, the base includes a profile bracket, a transformer, and a fixing bracket. A transformer is installed inside the left end of the profile bracket, and a fixing bracket is respectively fixed in the middle of the left side and the middle of the right side of the upper end of the profile bracket;

[0008] An installation plate is respectively installed on the left side and the right side of the upper end of the profile bracket. Three swing cylinders distributed in an equilateral triangle structure are installed on the outer surface of each installation plate. A swing pressure plate is fixed to the outer end of each swing cylinder, and the fixing bracket is placed outside the installation plate.

[0009] As a preferred embodiment, the driving assembly includes a first fixing box and a second fixing box. The structure and size of the first fixing box are the same as those of the second fixing box. An electric push rod is respectively installed inside the first fixing box and the second fixing box;

[0010] The right ends of the two electric push rods penetrate through the right ends of the first fixing box and the second fixing box to the right. An operation screen is fixed in the middle of the front side of the first fixing box. The setting of the driving part can drive the connecting plate of the placing component to move left or right when needed, thereby replacing manual feeding or discharging, greatly improving the automation ability of the equipment and reducing the operation difficulty of the operator.

[0011] As a preferred embodiment, the heating assembly includes a heat preservation box, an inner box, and a heating furnace. The inner box is installed inside the heat preservation box, and the heating furnace is installed inside the inner box. The heating furnace is a high-temperature furnace of 1700 degrees Celsius;

[0012] The center of the heat preservation box coincides with the center of the inner box, and the center of the inner box coincides with the center of the heating furnace.

[0013] As a preferred embodiment, the placing component includes a connecting plate, a sealing plate, and a support rod. A sealing plate is fixed in the middle of the left side of the connecting plate. The sealing plate is a circular plate, and an installation cylinder is arranged in the middle of the left end of the sealing plate;

[0014] The support rod is fixed to the left side of the sealing plate through the installation cylinder. The support rod is a graphite rod, and a supporting platform is fixed to the left end of the support rod. A rectangular groove is formed by downward depression on the upper surface of the left end of the supporting platform. The setting of the placing component, in cooperation with the driving component, can perform automatic feeding and discharging without manual feeding and discharging, improving the operation convenience of the equipment. At the same time, the crucible can be placed in the middle part of the inside of the corundum tube, which helps to improve the uniformity of crucible heating.

[0015] As a preferred embodiment, a crucible is movably placed at the left end of the support rod through a support platform. The bottom of the crucible is placed inside a rectangular groove. The crucible is a crucible made of alumina material. A pipe plug is fixed between the support platform and the left end of the installation cylinder for the support rod.

[0016] The pipe plug is a cylindrical alumina block. An intake pipe 1 is fixed in the middle of the right surface of the connecting plate. The left end of the intake pipe 1 penetrates through the connecting plate and the sealing plate to the left. The front side and the rear side of the connecting plate are respectively fixedly connected with the right end of the piston rod of an electric push rod.

[0017] As a preferred embodiment, the vacuum pipe fitting includes a corundum pipe, a water-cooled flange seat and a low-vacuum flange. The corundum pipe is a corundum pipe made of alumina material. The right end and the left end of the corundum pipe are respectively fixedly connected with the upper end of a fixing frame through a water-cooled flange seat. The middle part of the corundum pipe is placed in the middle of the heating furnace.

[0018] The left end and the right end of the corundum pipe respectively penetrate through the left side and the right side of the inner box and the heat preservation box to the left and to the right. The midpoint of the axis of the corundum pipe coincides with the center of the heating furnace. The left end and the right end of the corundum pipe are respectively hermetically connected with the left side and the right side of the inner box and the heat preservation box.

[0019] As a preferred embodiment, the left end of the corundum pipe is fixedly connected with the low-vacuum flange through a water-cooled flange seat. The low-vacuum flange includes a KF vacuum port, a pressure gauge and an intake pipe 2. The left end of the KF vacuum port is connected with a vacuum device. The intake pipe 2 is arranged on the lower side of the KF vacuum port. The pressure gauge is fixed on the upper side of the KF vacuum port.

[0020] The inner diameter of the corundum pipe matches the outer diameter of the pipe plug. The axis of the corundum pipe is collinear with the axis of the support rod. The axis of the corundum pipe is parallel to the axes of the two electric push rods in the same horizontal plane. The outer diameter of the corundum pipe is smaller than the diameter of the sealing plate. The right end of the corundum pipe is hermetically abutted against the left surface of the sealing plate.

[0021] After adopting the above technical solutions, the beneficial effects of the present invention are as follows: By setting the base, the drive assembly and the placement assembly, the automation degree of the whole device is relatively high. For experiments that require frequent use of the device to heat items, it can effectively improve the efficiency of the heating experiment and reduce the labor intensity of the operators at the same time.

[0022] Three swing cylinders distributed in a trisected structure can spin and lock the sealing plate when necessary, making it tightly abut against the right end face of the corundum tube, thereby ensuring the vacuum degree inside the corundum tube, contributing to enhancing the stability of vacuum heating, ensuring the stable progress of the vacuum heating experiment, and having simple operation without additional manual operation. Only by controlling the operation screen can the synchronous movement of the swing cylinders be controlled, greatly improving the operation convenience of the equipment and making the equipment have a high degree of automation performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0024] Figure 1 It is a schematic diagram of the overall structure of the high-temperature automatic tube furnace of the present invention.

[0025] Figure 2 It is a schematic side view of the high-temperature automatic tube furnace of the present invention.

[0026] Figure 3 It is a schematic top view of the high-temperature automatic tube furnace of the present invention.

[0027] Figure 4 It is a schematic diagram of the structure of the swing cylinder in the released state of the high-temperature automatic tube furnace of the present invention.

[0028] Figure 5 It is a schematic diagram of the structure of the electric push rod in the extended state of the high-temperature automatic tube furnace of the present invention.

[0029] Figure 6 It is a schematic diagram of the internal structure of the high-temperature automatic tube furnace of the present invention.

[0030] In the figure, 100 - base, 110 - profile bracket, 120 - transformer, 130 - fixing frame, 140 - mounting plate, 150 - swing cylinder, 151 - swing pressing plate;

[0031] 200 - drive assembly, 210 - fixing box one, 211 - operation screen, 212 - electric push rod, 220 - fixing box two;

[0032] 300 - heating assembly, 310 - heat preservation box, 320 - inner box, 330 - heating furnace;

[0033] 400 - Placement component, 410 - Crucible, 420 - Pipe plug, 430 - Support rod, 440 - Sealing plate, 450 - First intake pipe, 460 - Connection plate, 470 - Support platform;

[0034] 500 - Vacuum pipe fittings, 510 - Low - vacuum flange, 511 - Second intake pipe, 512 - Pressure gauge, 513 - KF vacuum port, 520 - Water - cooled flange seat, 530 - Sapphire tube. Detailed implementation mode

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0036] Please refer to Figures 1 to 6 , the present invention provides a technical solution: a high - temperature automatic tube furnace, including: a base 100, a driving component 200, a heating component 300, a placement component 400 and a vacuum pipe fitting 500. The driving component 200 is fixed on the front side and the rear side of the upper end of the base 100, and the heating component 300 is fixed in the middle of the upper end of the base 100;

[0037] The vacuum pipe fitting 500 is installed inside the heating component 300, the placement component 400 is movably installed at the right end of the driving component 200, and the left - hand part of the placement component 400 is movably installed inside the right - hand end of the vacuum pipe fitting 500 through the driving component 200.

[0038] Please refer to Figure 1 , Figure 4 , the base 100 includes a profile bracket 110, a transformer 120 and a fixing bracket 130. The transformer 120 is installed inside the left - hand end of the profile bracket 110, and a fixing bracket 130 is fixed in the middle of the left - hand side and the middle of the right - hand side of the upper end of the profile bracket 110 respectively;

[0039] An installation plate 140 is installed on the left - hand side and the right - hand side of the upper end of the profile bracket 110 respectively. Three rotary cylinders 150 distributed in an equilateral - triangle structure are installed on the outer surface of each installation plate 140, and a rotary pressure plate 151 is fixed at the outer end of each rotary cylinder 150. The fixing bracket 130 is placed outside the installation plate 140.

[0040] As the first embodiment of the present invention, three rotary cylinders 150 distributed in a trisected structure can spin and lock the sealing plate 440 when necessary, making it tightly abut against the right end face of the corundum tube 530, thereby ensuring the vacuum degree inside the corundum tube 530, contributing to improving the stability of vacuum heating, ensuring the stable progress of the vacuum heating experiment, and having simple operation without additional manual operation. Only by controlling the operation screen 211 can the synchronous movement of the rotary cylinders 150 be controlled, greatly improving the operation convenience of the equipment and making the equipment have a high degree of automation performance.

[0041] Please refer to Figures 1 to 6 , the driving assembly 200 includes a first fixed box 210 and a second fixed box 220. The structure and size of the first fixed box 210 are the same as those of the second fixed box 220. An electric push rod 212 is respectively installed inside the first fixed box 210 and the second fixed box 220;

[0042] The right ends of the two electric push rods 212 penetrate through the right ends of the first fixed box 210 and the second fixed box 220 to the right. An operation screen 211 is fixed in the middle of the front side of the first fixed box 210. The setting of the driving member can drive the connecting plate 460 of the placing assembly 400 to move left or right when needed, thereby replacing manual feeding or discharging, greatly improving the automation ability of the equipment and reducing the operation difficulty of the operator.

[0043] The heating assembly 300 includes a heat preservation box 310, an inner box 320 and a heating furnace 330. The inner box 320 is installed inside the heat preservation box 310, and the heating furnace 330 is installed inside the inner box 320. The heating furnace 330 is a high-temperature furnace of 1700 degrees Celsius;

[0044] The center of the heat preservation box 310 coincides with the center of the inner box 320, and the center of the inner box 320 coincides with the center of the heating furnace 330.

[0045] The placing assembly 400 includes a connecting plate 460, a sealing plate 440 and a support rod 430. The sealing plate 440 is fixed in the middle of the left side of the connecting plate 460. The sealing plate 440 is a circular plate, and an installation cylinder is arranged in the middle of the left end of the sealing plate 440;

[0046] The support rod 430 is fixed to the left side of the sealing plate 440 through the installation cylinder. The support rod 430 is a graphite rod, and a supporting platform 470 is fixed to the left end of the support rod 430. A rectangular groove is formed by downward depression on the upper surface of the left end of the supporting platform 470. The setting of the placing assembly 400, in cooperation with the driving assembly 200, can perform automatic feeding and discharging without manual loading and unloading, improving the operation convenience of the equipment. At the same time, the crucible 410 can be placed in the middle part inside the corundum tube 530, which helps to improve the heating uniformity of the crucible 410.

[0047] The left end of the support rod 430 is movably placed with a crucible 410 through a support platform. The bottom of the crucible 410 is placed inside a rectangular groove. The crucible 410 is a crucible made of alumina material. A pipe plug 420 is fixed between the support platform 470 and the left end of the installation cylinder for the support rod 430.

[0048] The pipe plug 420 is a cylindrical alumina block. An air inlet pipe 450 is fixed in the middle of the right surface of the connecting plate 460. The left end of the air inlet pipe 450 penetrates through the connecting plate 460 and the sealing plate 440 to the left. The front side and the rear side of the connecting plate 460 are respectively fixed to the right end of the piston rod of an electric push rod 212.

[0049] The vacuum pipe fitting 500 includes a corundum tube 530, a water-cooled flange seat 520 and a low-vacuum flange 510. The corundum tube 530 is a corundum tube made of alumina material. The right end and the left end of the corundum tube 530 are respectively fixed to the upper end of a fixing frame 130 through a water-cooled flange seat 520. The middle part of the corundum tube 530 is placed in the middle of the heating furnace 330.

[0050] The left end and the right end of the corundum tube 530 respectively penetrate through the left side and the right side of the inner box 320 and the heat preservation box 310 to the left and to the right. The axis midpoint of the corundum tube 530 coincides with the center of the heating furnace 330. The left end and the right end of the corundum tube 530 are respectively sealed and connected to the left side and the right side of the inner box 320 and the heat preservation box 310.

[0051] The left end of the corundum tube 530 is fixed to the low-vacuum flange 510 through the water-cooled flange seat 520. The low-vacuum flange 510 includes a KF vacuum port 513, a pressure gauge 512 and an air inlet pipe 511. The left end of the KF vacuum port 513 is connected to a vacuum device. The lower side of the KF vacuum port 513 is provided with the air inlet pipe 511. The pressure gauge 512 is fixed to the upper side of the KF vacuum port 513.

[0052] The inner diameter of the corundum tube 530 matches the outer diameter of the pipe plug 420. The axis of the corundum tube 530 is collinear with the axis of the support rod 430. The axis of the corundum tube 530 is parallel to the axes of the two electric push rods 212 in the same horizontal plane. The outer diameter of the corundum tube 530 is smaller than the diameter of the sealing plate 440. The right end of the corundum tube 530 is in sealed contact with the left surface of the sealing plate 440.

[0053] As the second embodiment of the present invention, based on the above-mentioned first embodiment, in actual use, the item to be heated is placed in the crucible 410, and then the crucible 410 is placed in the rectangular groove on the upper side of the supporting platform 470. Then, the two electric push rods 212 are controlled to contract synchronously through the operation screen 211 (the two electric push rods 212 are synchronous push rods and can perform synchronous telescopic movements. This is prior art and will not be elaborated here). Under the action of the synchronous contraction of the two electric push rods 212 on the driving assembly 200, the entire placement assembly 400 moves smoothly to the left. At this time, the supporting platform 470 at the left end of the support rod 430 together with the crucible 410 moves along the axis of the corundum tube 530 towards the middle part inside the corundum tube 530. After the two electric push rods 212 reach the maximum contraction stroke, the crucible 410 is exactly placed in the middle inside the corundum tube 530;

[0054] At this time, the sealing plate 440 on the left side of the connecting plate 460 abuts against the right end of the corundum tube 530, and the pipe plug 420 located on the support rod 430 also reaches the right side inside the corundum tube 530 to block the right part of the corundum tube 530. Subsequently, three swing cylinders 150 distributed in an equilateral triangle structure on the right side of the mounting plate 140 are started. When the swing cylinders 150 are started, the swing pressing plates 151 at the right ends of the swing cylinders 150 will move to the left and rotate 90 degrees during the movement, so that the sides of the three swing pressing plates 151 close to the sealing plate 440 abut against the edge of the sealing plate 440. The three swing pressing plates 151 fix the right side of the sealing plate 440 into three equal parts, and then tightly fix the sealing plate 440 at the right end of the corundum tube 530 (the surface finish of the right end of the corundum tube 530 and the left surface of the sealing plate 440 is relatively high, and they can fit well to form a sealing surface. The processing of the sealing surface is prior art), which helps to greatly improve the sealing performance and ensure the vacuum degree of the corundum tube 530 during operation;

[0055] Then, an external vacuum device can be used in cooperation with the low-vacuum flange 510 to evacuate the corundum tube 530. When necessary, protective gas can be input into the corundum tube 530 through the first inlet pipe 450 and the second inlet pipe 511. Subsequently, the heating furnace 330 can be controlled through the operation screen 211 to heat the crucible 410 inside the corundum tube 530. The automation degree of the entire device is relatively high. For experiments that require frequent heating of items using the equipment, it can effectively improve the efficiency of the heating experiment and reduce the labor intensity of the operators.

[0056] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. High-temperature automated tubular furnace, comprising: A base (100), a drive assembly (200), a heating assembly (300), a placement assembly (400), and a vacuum pipe fitting (500), characterized in that a drive assembly (200) is fixed to the front side and the rear side of the upper end of the base (100), and a heating assembly (300) is fixed to the middle of the upper end of the base (100); A vacuum pipe fitting (500) is installed inside the heating assembly (300), a placement assembly (400) is movably installed at the right end of the drive assembly (200), and a left part of the placement assembly (400) is movably installed inside the right end of the vacuum pipe fitting (500) through the drive assembly (200).

2. The high-temperature automatic tubular furnace according to claim 1, characterized in that: The base (100) includes a profile bracket (110), a transformer (120), and a fixing bracket (130). A transformer (120) is installed inside the left end of the profile bracket (110), and a fixing bracket (130) is respectively fixed to the middle of the left side and the middle of the right side of the upper end of the profile bracket (110); An installation plate (140) is respectively installed on the left side and the right side of the upper end of the profile bracket (110). Three swing cylinders (150) distributed in an equilateral triangle structure are installed on the outer surface of each installation plate (140). A swing pressing plate (151) is fixed to the outer end of each swing cylinder (150), and the fixing bracket (130) is placed outside the installation plate (140).

3. The high-temperature automatic tube furnace according to claim 2, wherein: The drive assembly (200) includes a first fixing box (210) and a second fixing box (220). The structure and size of the first fixing box (210) are the same as those of the second fixing box (220). An electric push rod (212) is respectively installed inside the first fixing box (210) and the second fixing box (220); The right ends of the two electric push rods (212) penetrate through the right ends of the first fixing box (210) and the second fixing box (220) to the right, and an operation screen (211) is fixed to the middle of the front side of the first fixing box (210).

4. The high-temperature automatic tube furnace according to claim 3, wherein: The heating assembly (300) includes a heat preservation box (310), an inner box (320), and a heating furnace (330). An inner box (320) is installed inside the heat preservation box (310), a heating furnace (330) is installed inside the inner box (320), and the heating furnace (330) is a high-temperature furnace at 1700 degrees Celsius; The center of the heat preservation box (310) coincides with the center of the inner box (320), and the center of the inner box (320) coincides with the center of the heating furnace (330).

5. The high-temperature automatic tube furnace according to claim 4, characterized in that: The placement assembly (400) includes a connecting plate (460), a sealing plate (440), and a support rod (430). A sealing plate (440) is fixed to the middle of the left side of the connecting plate (460). The sealing plate (440) is a circular plate, and an installation cylinder is arranged in the middle of the left end of the sealing plate (440); A support rod (430) is fixed to the left side of the sealing plate (440) through the installation cylinder. The support rod (430) is a graphite rod, a support platform (470) is fixed to the left end of the support rod (430), and a rectangular groove is formed by downward depression on the upper surface of the left end of the support platform (470).

6. The high-temperature automatic tube furnace according to claim 5, wherein: The left end of the support rod (430) is movably placed with a crucible (410) through a support platform. The bottom of the crucible (410) is placed inside a rectangular groove. The crucible (410) is a crucible made of alumina material. A pipe plug (420) is fixed between the support rod (430) and the left end of the mounting cylinder at the support platform (470). The pipe plug (420) is a cylindrical alumina block. An air inlet pipe 1 (450) is fixed in the middle of the right surface of the connecting plate (460). The left end of the air inlet pipe 1 (450) penetrates through the connecting plate (460) and the sealing plate (440) to the left. The front side and the rear side of the connecting plate (460) are respectively fixedly connected with the right end of the piston rod of an electric push rod (212).

7. The high-temperature automatic tube furnace according to claim 6, wherein: The vacuum pipe fitting (500) includes a corundum tube (530), a water-cooled flange seat (520) and a low-vacuum flange (510). The corundum tube (530) is a corundum tube made of alumina material. The right end and the left end of the corundum tube (530) are respectively fixedly connected with the upper end of a fixing frame (130) through a water-cooled flange seat (520). The middle part of the corundum tube (530) is placed in the middle of the heating furnace (330). The left end and the right end of the corundum tube (530) penetrate through the left side and the right side of the inner box (320) and the heat preservation box (310) to the left and to the right respectively. The axis midpoint of the corundum tube (530) coincides with the center of the heating furnace (330). The left end and the right end of the corundum tube (530) are respectively hermetically connected with the left side and the right side of the inner box (320) and the heat preservation box (310).

8. The high-temperature automatic tubular furnace according to claim 7, characterized in that: The left end of the corundum tube (530) is fixedly connected with the low-vacuum flange (510) through the water-cooled flange seat (520). The low-vacuum flange (510) includes a KF vacuum port (513), a pressure gauge (512) and an air inlet pipe 2 (511). The left end of the KF vacuum port (513) is connected with a vacuum device. The air inlet pipe 2 (511) is arranged on the lower side of the KF vacuum port (513). The pressure gauge (512) is fixed on the upper side of the KF vacuum port (513). The inner diameter of the corundum tube (530) matches the outer diameter of the pipe plug (420). The axis of the corundum tube (530) is collinear with the axis of the support rod (430). The axis of the corundum tube (530) is parallel to the axes of the two electric push rods (212) in the same horizontal plane. The outer diameter of the corundum tube (530) is smaller than the diameter of the sealing plate (440). The right end of the corundum tube (530) is hermetically abutted against the left surface of the sealing plate (440).

Images