阅读说明：本技术 一种箱式真空、气氛中频感应烧结炉及使用方法 (Box type vacuum and atmosphere medium-frequency induction sintering furnace and using method ) 是由 赵敏 陈志海 王建龙 鲁平瑞 严磊 于 2021-01-07 设计创作，主要内容包括：本发明属于钨钼加工设备领域,特别涉及一种箱式真空、气氛中频感应烧结炉。一种箱式真空、气氛中频感应烧结炉,包括炉壳体、位于所述炉壳体内部的炉芯组件、与所述炉壳体连接的真空系统、水路系统以及气路系统,所述的炉芯组件为长方体箱型结构,长方体箱型结构四周从内向外依次设有发热体、耐火材料、感应线圈,长方体箱型结构顶部设有炉顶盖；所述的真空系统为所述的炉壳体内部提供真空环境,所述的水路系统为所述炉壳体提供冷却水,所述的气路系统为所述炉壳体提供工作气体。本发明通过采用箱式结构炉膛,将被烧结的钨钼板坯制品水平放置在放料底托上,最大限度改善了被烧结材料的弯曲变形,减少钨钼制品的校直校平工序,降低生产成本。(The invention belongs to the field of tungsten and molybdenum processing equipment, and particularly relates to a box type vacuum and atmosphere medium-frequency induction sintering furnace. A box-type vacuum and atmosphere medium-frequency induction sintering furnace comprises a furnace shell, a furnace core assembly, a vacuum system, a water path system and an air path system, wherein the furnace core assembly is positioned inside the furnace shell, the vacuum system, the water path system and the air path system are connected with the furnace shell, the furnace core assembly is of a cuboid box-type structure, a heating body, a refractory material and an induction coil are sequentially arranged around the cuboid box-type structure from inside to outside, and a furnace top cover is arranged at the top of the cuboid box-type structure; the vacuum system provides a vacuum environment for the interior of the furnace shell, the water path system provides cooling water for the furnace shell, and the gas path system provides working gas for the furnace shell. According to the invention, the box-type structure hearth is adopted, and the sintered tungsten-molybdenum plate blank product is horizontally placed on the discharging bottom support, so that the bending deformation of the sintered material is improved to the maximum extent, the straightening and leveling procedures of the tungsten-molybdenum product are reduced, and the production cost is reduced.)

1. The utility model provides a box vacuum, atmosphere intermediate frequency induction sintering stove which characterized in that: including furnace casing (1), be located furnace core subassembly inside furnace casing (1), with vacuum system (6), waterway system (7) and gas circuit system (8) that furnace casing (1) is connected, wherein: the furnace core assembly is of a cuboid box-shaped structure, a heating body (2), a refractory material (3) and an induction coil (4) are sequentially arranged around the cuboid box-shaped structure from inside to outside, and a furnace top cover (5) is arranged at the top of the cuboid box-shaped structure; the vacuum system (6) provides a vacuum environment inside the furnace shell (1), the waterway system (7) provides cooling water for the furnace shell (1), and the gas circuit system (8) provides working gas for the furnace shell (1).

2. The box-type vacuum, atmosphere medium frequency induction sintering furnace of claim 1, characterized in that: the furnace shell (1) is of a horizontal circular double-layer water-cooling sleeve structure and is formed by welding a sealing head (26), a barrel (27) and a flange (32), an observation window temperature measuring hole (29), an upper furnace body water outlet (28) and an air inlet (30) are respectively arranged at the central position of the top of the barrel (27) of the furnace shell (1), lifting lugs (31) are respectively arranged on two sides of the top of the barrel (27) of the furnace shell (1), two ends of the sealing head (26) are close to the upper portion of the flange (32) and are respectively provided with an upper furnace body water inlet I (25) and an upper furnace body water inlet II (33), two ends of the sealing head (26) are close to the lower portion of the flange (32) and are respectively provided with a lower furnace body water outlet I (34) and a lower furnace body water outlet II (39), a water-cooling electrode connecting hole (35) is arranged on the sealing head (26) below the lower portion of the lower furnace body water outlet, The gas explosion-proof furnace shell is characterized by comprising exhaust holes (38), wherein supporting legs (36) are respectively arranged on two sides of the bottom of a cylinder (27) of the furnace shell (1), the supporting legs (36) are of a saddle-type support structure, and a vacuum system connection hole (23) and an explosion-proof device connection hole (24) are respectively arranged on two sides of the middle of the cylinder (27) of the furnace shell (1) close to the lower portion of a flange (32).

3. The box-type vacuum, atmosphere medium frequency induction sintering furnace according to claim 1 or 2, characterized in that: vacuum system (6) with furnace casing (1) is through vacuum system connects hole (23) and is connected, gas circuit system (8) respectively with inlet port (30), exhaust hole (38) of furnace casing (1) are connected and are formed gaseous return circuit, waterway system (7) include a plurality of inlet channel and a plurality of return water pipeline, waterway system (7) respectively with go up furnace body water inlet I (25), go up furnace body water inlet II (33), lower furnace body inlet opening (37) are connected and are formed three inlet channel, waterway system (7) respectively with lower furnace body outlet I (34), lower furnace body outlet II (39), last furnace body outlet (28) are connected and are formed three return water pipeline.

4. The box-type vacuum, atmosphere medium frequency induction sintering furnace of claim 1, characterized in that: the heating body (2) is formed by stacking a molybdenum strip and a tungsten strip in a four-corner lap joint mode.

5. The box-type vacuum, atmosphere medium frequency induction sintering furnace of claim 4, characterized in that: the molybdenum strip and the tungsten strip are cuboids, and the specifications of the cuboids are 40 multiplied by 20 multiplied by 800-1000 mm.

6. The box-type vacuum, atmosphere medium frequency induction sintering furnace of claim 1, characterized in that: the fireproof material (3) is square, and the fireproof material (3) comprises two layers, namely a zirconium oxide inner layer and an aluminum oxide outer layer.

7. The box-type vacuum, atmosphere medium frequency induction sintering furnace of claim 6, characterized in that: the thickness of the inner zirconia layer is 50mm, and the thickness of the outer alumina layer is 40 mm.

8. The box-type vacuum, atmosphere medium frequency induction sintering furnace of claim 1, characterized in that: the furnace top cover (5) is formed by directly stacking an alumina fiber board (18), an alumina hollow ball brick (19), a zirconia hollow ball brick (20), a tungsten board (21) and a tungsten bracket (22) from top to bottom in sequence.

9. The box-type vacuum, atmosphere medium frequency induction sintering furnace of claim 1, characterized in that: the vacuum system (6) comprises a diffusion pump (10), an oil adding pump (11), a maintaining pump (13), a roots pump (14) and a slide valve pump (15) which are connected by vacuum pipelines, wherein: the diffusion pump (10) is connected with the furnace shell (1) through the vacuum system connecting hole (23), a vacuum pressure gauge (9) is arranged on a vacuum pipeline between the diffusion pump (10) and the furnace shell (1), the booster pump (11) is connected with the diffusion pump (10), the rosy pump (14) is connected with the diffusion pump (10) and the booster pump (11), a vacuum baffle valve (17) is arranged on a vacuum pipeline between the compass pump (14) and the diffusion pump (10), the slide valve pump (15) is connected with the roots pump (14), an electromagnetic vacuum belt inflating pressure valve (16) is arranged on a vacuum pipeline between the roots pump (14) and the slide valve pump (15), the maintaining pump (13) is respectively connected with the booster pump (11) and the diffusion pump (10), and the vacuum pipeline adopts a vacuum corrugated pipe.

10. A method for using a box-type vacuum and atmosphere medium-frequency induction sintering furnace, which uses any one of the box-type vacuum and atmosphere medium-frequency induction sintering furnaces of claims 1 to 9, and is characterized in that: the method comprises the following steps:

s1, placing the material to be sintered into the uniform temperature area of the medium frequency induction sintering furnace, covering the furnace top cover (5) and completing the charging of the box type vacuum medium frequency induction sintering furnace;

s2: starting a medium-frequency induction sintering furnace;

when the working mode is vacuum sintering, firstly, a slide valve pump (15) is started to vacuumize a furnace shell (1), an oil increasing pump (11) and a diffusion pump (10); starting the roots pump (14) when the vacuum degree in the furnace shell (1) reaches 700Pa, starting the heating power supply of the oil increasing pump (11) and the diffusion pump (10) when the vacuum degree of the oil increasing pump (11) and the diffusion pump (10) reaches 20Pa, heating the oil temperature in the pump, and pumping the oil to 8x10 when the pressure in the furnace reaches^-1Pa, the oil increasing pump (11) is put into use; when the pressure in the furnace is pumped to 8x10^-2When Pa is needed, the diffusion pump (10) is put into use, and when the pressure in the furnace is pumped to 2x10^-2When Pa is needed, the vacuum heating condition is allowed, the intermediate frequency power supply can be started to heat, and the pressure in the furnace is reduced to 8x10 due to the large volatile matter in the heating process^-1When Pa is needed, the oil increasing pump (11) is switched to work; when the pressure in the furnace is pumped to 8x10^-2When Pa is reached, the diffusion pump (10) is switched to vacuumize the furnace, and when the pressure drops by 8x10 again^-1Repeating the working procedure when Pa is reached; heating and preserving the temperature to the process temperature according to the process requirement, cooling or furnace cooling after the sintering process is finished, and finishing the whole sintering process, thereby removing oxygen and other impurity elements of the blank, densifying the blank and producing a product meeting the performance requirement;

when the working mode selects the atmosphere sintering: starting a slide valve pump (15) to vacuumize a furnace shell (1), stopping the slide valve pump (15) when the furnace pressure reaches 9KPa, stopping vacuumizing, filling nitrogen into the furnace shell (1) through a gas path system (8) after the vacuumizing is finished, increasing the pressure in the furnace, and stopping gas inlet when the furnace is inflated to a pressure value of 103 KPa; vacuumizing again, starting a slide valve pump (15), vacuumizing the furnace shell (1), stopping the slide valve pump (15) when the furnace pressure reaches 9KPa, and stopping vacuumizing; after the process is finished, quickly filling hydrogen into the furnace shell (1) through the gas path system (8), increasing the furnace pressure to a pressure value of 95KPa, converting to work filling hydrogen, continuously filling hydrogen into the furnace chamber, after the furnace pressure is increased to a pressure value of 103KPa, opening the exhaust holes (38), sealing with water to give out gas, collecting the hydrogen in the furnace at each sampling port of the furnace body, performing a detonation test, after the test is qualified, confirming that no residual air exists in the furnace chamber, starting the intermediate frequency power supply to heat and raise the temperature, raising the temperature to the process temperature according to the process requirements, cooling or furnace cooling after the sintering process is finished, and finishing the whole sintering process, thereby removing oxygen and other impurity elements of the blank, densifying the blank and producing the product meeting the performance requirements.

Technical Field

The invention belongs to the field of tungsten and molybdenum processing equipment, and particularly relates to a box type vacuum and atmosphere medium-frequency induction sintering furnace and a using method thereof.

Background

The vacuum and atmosphere medium frequency induction sintering furnace is an important device widely used in the special metal processing industry of tungsten, molybdenum and the like. Induction heating is one of the good forms of electric heating, and is characterized by that it utilizes the faraday electromagnetic induction principle to convert electric energy into heat energy, and makes the three-phase power supply pass through the medium-frequency induction power supply and change it into medium-frequency alternating current, and after the alternating current passes through the induction coil, it can produce alternating induction magnetic field, i.e. can produce alternating magnetic flux whose size and direction can be changed with time. When a piece of conductive metal (namely tungsten and molybdenum workpieces) is placed in the induction coil, corresponding induced electromotive force can be generated inside the metal according to a Faraday's law of electromagnetic induction, the induced current can be generated due to the existence of the induced electromotive force even if the metal is a conductor, the induced current is called eddy current, and according to the Joule-Lenz's law, the eddy current can generate certain heat when flowing inside the metal with certain resistance, so that the metal is heated.

At present, a vacuum and atmosphere medium-frequency induction sintering furnace which is conventionally used is vertical and circular, and when a plate blank is sintered, the space utilization rate is low, so that the requirement for large-scale sintering of the plate blank cannot be met. In the sintering process, due to insufficient charging, the plate blank is easy to deform in the sintering process, so that the subsequent processing and manufacturing are inconvenient, in order to save cost, the deformed plate blank needs to be heated and corrected, the production cost is increased, and the quality of a product is influenced by heating and pressure processing in the correcting process; the circular coil has low space utilization rate, so that the energy consumption is high and the efficiency is low in the using process.

Disclosure of Invention

In view of the above problems, the present invention provides a box-type vacuum and atmosphere medium frequency induction sintering furnace and a method for using the same, wherein a box-type structure hearth is adopted, so that a sintered tungsten-molybdenum plate blank product can be horizontally placed on a discharging bottom support, the bending deformation of the sintered material is improved to the maximum extent, the straightening and leveling procedures of the tungsten-molybdenum product are greatly reduced, the production cost is reduced, and the influence of heating and pressure processing in the shaping process on the product quality is avoided.

The technical scheme of the invention is as follows: the utility model provides a box vacuum, atmosphere intermediate frequency induction sintering stove, includes the furnace casing, is located furnace core subassembly inside the furnace casing, with vacuum system, waterway system and the gas circuit system that the furnace casing is connected, wherein: the furnace core assembly is of a cuboid box-shaped structure, a heating body, a refractory material and an induction coil are sequentially arranged around the cuboid box-shaped structure from inside to outside, and a furnace top cover is arranged at the top of the cuboid box-shaped structure; the vacuum system provides a vacuum environment for the interior of the furnace shell, the water path system provides cooling water for the furnace shell, and the gas path system provides working gas for the furnace shell.

The furnace shell is of a horizontal circular double-layer water-cooling jacket structure and is formed by welding a sealing head, a cylinder body and a flange, an observation window temperature measuring hole, an upper furnace body water outlet and an air inlet are formed in the center of the top of the cylinder body of the furnace shell respectively, lifting lugs are arranged on two sides of the top of the cylinder body of the furnace shell respectively, an upper furnace body water inlet I and an upper furnace body water inlet II are arranged at two ends of the sealing head close to the upper portion of the flange respectively, a lower furnace body water outlet I and a lower furnace body water outlet II are arranged at two ends of the sealing head close to the lower portion of the flange respectively, a water-cooling electrode connecting hole is formed in the sealing head below the lower furnace body water outlet I, a lower furnace body water inlet hole and an air outlet are formed in the center of the bottom of the cylinder body of the furnace shell respectively, supporting legs are arranged on, The explosion-proof device is connected with the hole.

The vacuum system with the furnace casing passes through the vacuum system connect the hole and is connected, the gas circuit system respectively with the inlet port of furnace casing, exhaust hole are connected and are formed gaseous return circuit, the waterway system includes a plurality of inlet channel and a plurality of return water pipeline, the waterway system respectively with go up furnace body water inlet I, go up furnace body water inlet II, lower furnace body inlet hole are connected and are formed three inlet channel, the waterway system respectively with lower furnace body outlet I, lower furnace body outlet II, last furnace body outlet are connected and are formed three return water pipeline.

The heating body is formed by stacking molybdenum strips and tungsten strips in a four-corner lap joint mode.

The molybdenum strip and the tungsten strip are cuboids, and the specifications of the cuboids are 40 multiplied by 20 multiplied by 800-1000 mm.

The refractory material is square, and the refractory material has two layers, namely a zirconia inner layer and an alumina outer layer in sequence.

The thickness of the inner zirconia layer is 50mm, and the thickness of the outer alumina layer is 40 mm.

The furnace top cover is formed by directly stacking an alumina fiberboard, an alumina bubble brick, a zirconia bubble brick, a tungsten plate and a tungsten bracket from top to bottom in sequence.

The vacuum system comprises a diffusion pump, an oil increasing pump, a maintaining pump, a roots pump and a slide valve pump which are connected by a vacuum pipeline, wherein: the diffusion pump is connected with the furnace shell through the vacuum system connection hole, a vacuum pressure gauge is arranged on a vacuum pipeline between the diffusion pump and the furnace shell, the booster pump is connected with the diffusion pump, the compass pump is connected with the diffusion pump and the booster pump, a vacuum baffle valve is arranged on the vacuum pipeline between the compass pump and the diffusion pump, the slide valve pump is connected with the roots pump, an electromagnetic vacuum belt inflation pressure valve is arranged on the vacuum pipeline between the roots pump and the slide valve pump, the maintaining pump is respectively connected with the booster pump and the diffusion pump, and the vacuum pipeline adopts a vacuum corrugated pipe.

A use method of a box type vacuum and atmosphere medium-frequency induction sintering furnace uses any one of the box type vacuum and atmosphere medium-frequency induction sintering furnaces, and comprises the following steps:

s1, placing the material to be sintered into the uniform temperature area of the medium-frequency induction sintering furnace, covering the furnace top cover, and completing the charging of the box-type vacuum medium-frequency induction sintering furnace;

s2: starting a medium-frequency induction sintering furnace;

when the working mode selects vacuum sintering, firstly, a slide valve pump is started to pump a furnace shell, an oil adding pump and a diffusion pump to be vacuumized; starting the Roots pump when the vacuum degree in the furnace shell reaches 700Pa, starting the heating power supply of the oil increasing pump and the diffusion pump when the vacuum degree of the oil increasing pump and the diffusion pump reaches 20Pa, heating the oil temperature in the pumps, and pumping the pressure in the furnace to 8x10^-1Pa, putting the oil increasing pump into use; when the pressure in the furnace is pumped to 8x10^-2When Pa, the diffusion pump is put into use, and when the pressure in the furnace is pumped to 2x10^-2When Pa is needed, the vacuum heating condition is allowed, the intermediate frequency power supply can be started to heat, and the pressure in the furnace is reduced to 8x10 due to the large volatile matter in the heating process^-1When Pa, the pump is switched to oil to increase the work of the pump; when the pressure in the furnace is pumped to 8x10^-2When Pa is reached, the diffusion pump is switched to vacuumize the furnace, and when the pressure drops by 8x10 again^-1Repeating the working procedure when Pa is reached; heating and preserving the temperature to the process temperature according to the process requirement, cooling or furnace cooling after the sintering process is finished, and finishing the whole sintering process, thereby removing oxygen and other impurity elements of the blank, densifying the blank and producing a product meeting the performance requirement;

when the working mode selects the atmosphere sintering: starting a slide valve pump to vacuumize a furnace shell, stopping the slide valve pump when the furnace pressure reaches 9KPa, stopping vacuumizing, filling nitrogen into the furnace shell through a gas path system after the vacuumizing is finished, increasing the pressure in the furnace, and stopping gas inlet when the furnace shell is inflated to a pressure value of 103 KPa; vacuumizing again, starting a slide valve pump, vacuumizing the furnace shell, stopping the slide valve pump when the furnace pressure reaches 9KPa, and stopping vacuumizing; after the process is finished, quickly filling hydrogen into the furnace shell through the gas path system, increasing the furnace pressure to a pressure value of 95KPa, converting to work filling hydrogen, continuously filling hydrogen into the furnace chamber, increasing the furnace pressure to a pressure value of 103KPa, opening the exhaust hole, sealing the water to give out gas, collecting the hydrogen in the furnace at each sampling port of the furnace body, performing a detonation test, determining whether residual air is not in the furnace chamber after the test is qualified, starting the intermediate frequency power supply to heat up, increasing the temperature to the process temperature according to the process requirement, cooling or cooling along with the furnace after the sintering process is finished, and finishing the whole sintering process, thereby removing oxygen and other impurity elements of the blank, densifying the blank and producing a product meeting the performance requirement.

The invention has the technical effects that: 1. the furnace core assembly adopts a rectangular box-shaped structure, and a sintered tungsten-molybdenum plate blank product is horizontally placed on the discharging bottom support, so that the bending deformation of the sintered material is improved to the maximum extent, the straightening and leveling procedures of the tungsten-molybdenum product are greatly reduced, the production cost is reduced, and the influence of heating and pressure processing on the quality of the product in the shaping process is avoided; 2. the furnace shell adopts a horizontal circular structure, and compared with a vertical circular structure, the furnace shell greatly increases the charging utilization rate of the hearth and greatly reduces the energy consumption.

The following will be further described with reference to the accompanying drawings.

Drawings

FIG. 1 is a front view of a box-type vacuum and atmosphere medium frequency induction sintering furnace according to the present invention.

FIG. 2 is a side view of a box-type vacuum, atmosphere medium frequency induction sintering furnace according to the present invention.

FIG. 3 is a top view of a box-type vacuum and atmosphere medium frequency induction sintering furnace according to the present invention.

FIG. 4 is a schematic diagram of a furnace top cover structure of a box-type vacuum and atmosphere medium-frequency induction sintering furnace according to the present invention.

Reference numerals: 1-furnace shell, 2-heating body, 3-square refractory material, 4-induction coil, 5-furnace top cover, 6-vacuum system, 7-water path system, 8-gas path system, 9-vacuum gauge, vacuum pressure gauge, 10-diffusion pump, 11-oil increasing pump, 13-maintaining pump, 14-roots pump, 15-slide valve pump, 16-electromagnetic vacuum belt inflation pressure valve, 17-vacuum baffle valve, 18-alumina fiber board, 19-alumina hollow ball brick, 20-zirconia hollow ball brick, 21-tungsten board, 22-tungsten bracket, 23-vacuum system connection hole, 24-explosion-proof device connection hole, 25-upper furnace body water inlet I, 26-end enclosure, 27-cylinder body, 28-upper furnace body water outlet, 29-observation window temperature measuring hole, 30-air inlet, 31-lifting lug, 32-flange, 33-upper furnace body water inlet II, 34-lower furnace body water outlet I, 35-water cooling electrode connecting hole, 36-supporting leg, 37-lower furnace body water inlet hole, 38-exhaust hole and 39-lower furnace body water outlet II.

Detailed Description

Example 1

In order to solve the problems that the space utilization rate of the existing vertical circular structure sintering furnace is low when a plate blank is sintered, the plate blank is easy to deform in the sintering process, and subsequent processing and manufacturing are inconvenient, the invention provides the box type vacuum and atmosphere medium-frequency induction sintering furnace as shown in figure 1.

As shown in fig. 1 and 2, a box-type vacuum and atmosphere medium-frequency induction sintering furnace comprises a furnace shell 1, a furnace core assembly located inside the furnace shell 1, a vacuum system 6 connected with the furnace shell 1, a water path system 7 and a gas path system 8, wherein: the furnace core assembly is of a cuboid box-shaped structure, a heating body 2, a refractory material 3 and an induction coil 4 are sequentially arranged around the cuboid box-shaped structure from inside to outside, and a furnace top cover 5 is arranged at the top of the cuboid box-shaped structure; the vacuum system 6 provides a vacuum environment for the interior of the furnace shell 1, the waterway system 7 provides cooling water for the furnace shell 1, and the gas circuit system 8 provides working gas for the furnace shell 1.

The furnace core assembly is of a cuboid box-shaped structure, a refractory material 3 is used as a heat preservation and insulation material, an induction coil 4 is used for induction heating, a vacuum unit is used for vacuumizing the heating furnace, a water path system 7 provides cooling water for a furnace shell, a gas path system 8 provides working gas for the heating furnace, and tungsten and molybdenum materials are guaranteed not to be oxidized in the sintering process.

Example 2

Preferably, on the basis of embodiment 1, in this embodiment, the furnace shell 1 is a horizontal circular double-layer water-cooling jacket structure, and is formed by welding a head 26, a cylinder 27 and a flange 32, an observation window temperature measuring hole 29, an upper furnace body water outlet 28 and an air inlet 30 are respectively arranged at the central position of the top of the cylinder 27 of the furnace shell 1, lifting lugs 31 are respectively arranged on two sides of the top of the cylinder 27 of the furnace shell 1, an upper furnace body water inlet i 25 and an upper furnace body water inlet ii 33 are respectively arranged at two ends of the head 26 close to the upper part of the flange 32, a lower furnace body water outlet i 34 and a lower furnace body water outlet ii 39 are respectively arranged at two ends of the head 26 close to the lower part of the flange 32, a water-cooling electrode connection hole 35 is arranged on the head 26 below the lower furnace body water outlet i 34, a lower furnace body water inlet 37 and an air outlet 38 are respectively arranged at the central position of the bottom of the, the supporting leg 36 is of a saddle-type support structure, and a vacuum system connection hole 23 and an anti-riot device connection hole 24 are respectively arranged at the middle part of the cylinder 27 of the furnace shell 1 and close to the two sides of the lower part of the flange 32.

In the practical use process, the furnace shell 1 is of a horizontal circular double-layer water-cooling sleeve structure, the inner layer is made of stainless steel, the outer layer is made of carbon steel, a hydraulic test is carried out after welding is finished, the pressure is maintained at 0.4Mpa for 24 hours, no leakage, abnormal sound and obvious deformation exist, and the long-term use of the furnace shell is guaranteed.

Preferably, the vacuum system 6 is connected with the furnace shell 1 through the vacuum system connection hole 23, the gas path system 8 is respectively connected with the gas inlet 30 and the gas outlet 38 of the furnace shell 1 to form a gas loop, the water path system 7 comprises a plurality of water inlet pipelines and a plurality of water return pipelines, the water path system 7 is respectively connected with the upper furnace body water inlet I25, the upper furnace body water inlet II 33 and the lower furnace body water inlet 37 to form three water inlet pipelines, and the water path system 7 is respectively connected with the lower furnace body water outlet I34, the lower furnace body water outlet II 39 and the upper furnace body water outlet 28 to form three water return pipelines.

In the actual use process, the vacuum system 6 provides a vacuum environment for the interior of the furnace shell 1, the water path system 7 provides cooling water for the furnace shell 1, and the gas path system 8 provides working gas for the furnace shell 1, so that the requirement of multi-working-condition use is met.

Preferably, the heating element 2 is formed by stacking molybdenum strips and tungsten strips in a four-corner lap joint manner. The molybdenum strip and the tungsten strip are cuboids, and the specifications of the cuboids are 40 multiplied by 20 multiplied by 800-1000 mm.

In the actual use process, the heating body 2 is made of tungsten or high-temperature molybdenum materials and is built by adopting molybdenum strips or tungsten strips with the thickness of 40 multiplied by 20 multiplied by 800-1000 mm. Follow the principle of stagger joint from top to bottom during the assembly, what four angles overlap joint modes adopted is the right angle overlap joint mode, and four angle ends reserve has the expansion gap, and the deformation that produces is less among the heating process. The finger buckles between the strips adopt the form of male and female finger buckles, so that the phenomenon that the strips run out due to stronger magnetic field in the heating process is prevented. The width of the heating element strip is controlled to be 30-40 mm, and the thickness of the heating element strip is controlled to be about 20mm, so that the stability of the heating element in the installation process can be guaranteed, and the deformation of the heating element in the heating process can also be guaranteed.

The refractory material 3 is square, and the refractory material 3 comprises two layers, namely a zirconium oxide inner layer and an aluminum oxide outer layer in sequence. The thickness of the inner zirconia layer is 50mm, and the thickness of the outer alumina layer is 40 mm.

In the actual use process, the square refractory material 3 consists of an inner zirconia layer and an outer alumina layer, the thickness of the inner zirconia layer is 50mm, the thickness of the outer alumina layer is 40mm, the four surfaces of the refractory material 3 are independent surfaces, the principle of up-down staggered joints is followed when bricks are built, finger buttons are reserved between the bricks up and down and left and right, the structure has good high-temperature structural strength and good thermal stability and chemical stability, and the use under the conditions of maximum temperature 2300 ℃ full load and the like is met.

Preferably, as shown in fig. 4, the furnace roof 5 is composed of an alumina fiber plate 18, an alumina bubble brick 19, a zirconia bubble brick 20, a tungsten plate 21 and a tungsten bracket 22 which are directly stacked from top to bottom.

In the actual use process, the tungsten support 22 ensures that the flat top cover can be used for a long time in the heating process, the tungsten plate 21 is used for placing the alumina bubble brick 19 and the zirconia bubble brick 20 which are refractory heat-insulating bricks, and the alumina refractory fiber vertebral plate 18 is paved on the heat-insulating bricks, so that the heat can be preserved and the large heat can be prevented from being dissipated from the top. The structure not only reduces the volume of the hearth and ensures that the temperature of the heating furnace is more uniform, but also has stable flat top structure and can be used for a long time.

As shown in fig. 3, the vacuum system 6 preferably includes a diffusion pump 10, an oil adding pump 11, a maintaining pump 13, a roots pump 14, and a slide valve pump 15 connected by vacuum pipes, wherein: the diffusion pump 10 is connected with the furnace shell 1 through the vacuum system connection hole 23, a vacuum pressure gauge 9 is arranged on a vacuum pipeline between the diffusion pump 10 and the furnace shell 1, the booster pump 11 is connected with the diffusion pump 10, the roots pump 14 is connected with the diffusion pump 10 and the booster pump 11, a vacuum baffle valve 17 is arranged on the vacuum pipeline between the roots pump 14 and the diffusion pump 10, the slide valve pump 15 is connected with the roots pump 14, an electromagnetic vacuum belt inflation pressure valve 16 is arranged on the vacuum pipeline between the roots pump 14 and the slide valve pump 15, the maintenance pump 13 is respectively connected with the booster pump 11 and the diffusion pump 10, and the vacuum pipeline adopts a vacuum corrugated pipe.

In actual use, in order to reduce the vibration of the furnace body, the vacuum pipeline is connected with the pump by adopting a metal corrugated pipe, and the vacuum measurement is measured by a vacuum pressure gauge 9. The vacuum system 6 is provided with a vacuum filter to filter particle impurities such as dust, and the like, so that the service life of the vacuum pump is prolonged. During vacuum sintering, the mechanical pump 15 is started to vacuumize the furnace body, the Roots pump 14, the diffusion pump 10, the oil increasing pump 11 and the maintaining pump 13 are started in sequence after a preset vacuum degree is reached, the temperature is raised and preserved according to the process requirement, the temperature is reduced after the sintering process is completed, the temperature is controlled to be reduced or cooled along with the furnace, the whole sintering process is completed, so that oxygen and other impurity elements of blanks in the furnace are removed, the blanks are densified, and products meeting the performance requirement are produced.

Example 3

A use method of a box type vacuum and atmosphere medium-frequency induction sintering furnace uses any one of the box type vacuum and atmosphere medium-frequency induction sintering furnaces, and the specific process is as follows:

s1, placing the material to be sintered into the uniform temperature area of the medium-frequency induction sintering furnace, covering the furnace top cover 5, and completing the charging of the box-type vacuum medium-frequency induction sintering furnace;

s2: starting a medium-frequency induction sintering furnace;

when the working mode selects vacuum sintering, firstly, a slide valve pump 15 is started to vacuumize the furnace shell 1, the oil increasing pump 11 and the diffusion pump 10; starting the Roots pump 14 when the vacuum degree in the furnace shell 1 reaches 700Pa, starting the heating power supply of the oil increasing pump 11 and the diffusion pump 10 when the vacuum degree of the oil increasing pump 11 and the diffusion pump 10 reaches 20Pa, heating the oil temperature in the pumps, and pumping the pressure in the furnace to 8x10^-1Pa, the oil increasing pump 11 is put into use; when the pressure in the furnace is pumped to 8x10^-2Pa, the diffusion pump 10 was put into operation, and the pressure in the furnace was increased to 2X10^-2When Pa is needed, the vacuum heating condition is allowed, the intermediate frequency power supply can be started to heat, and the pressure in the furnace is reduced to 8x10 due to the large volatile matter in the heating process^-1When Pa, the pump 11 is switched to oil to work; when the pressure in the furnace is pumped to 8x10^-2When Pa is reached, the diffusion pump 10 is switched to vacuumize the furnace, and when the pressure drops by 8x10 again^-1Repeating the working procedure when Pa is reached; heating and preserving the temperature to the process temperature according to the process requirement, cooling or furnace cooling after the sintering process is finished, and finishing the whole sintering process, thereby removing oxygen and other impurity elements of the blank, densifying the blank and producing a product meeting the performance requirement;

when the working mode selects the atmosphere sintering: starting a slide valve pump 15 to vacuumize the furnace shell 1, stopping the slide valve pump 15 when the furnace pressure reaches 9KPa, stopping vacuumizing, filling nitrogen into the furnace shell 1 through a gas path system 8 after the vacuumizing is finished, increasing the pressure in the furnace, and stopping gas inlet when the furnace is filled to a pressure value of 103 KPa; vacuumizing again, starting the slide valve pump 15, vacuumizing the furnace shell 1, stopping the slide valve pump 15 when the furnace pressure reaches 9KPa, and stopping vacuumizing; after the process is finished, hydrogen is quickly filled into the furnace shell 1 through the gas path system 8, the furnace pressure rises to a pressure value of 95KPa, the operation is changed into charging hydrogen, the furnace cavity is continuously charged with hydrogen, the furnace pressure rises to a pressure value of 103KPa, then the exhaust hole 38 is opened, the water seal is sealed to discharge gas, the hydrogen in the furnace is collected at each sampling port of the furnace body, a detonation test is carried out, after the test is qualified, no residual air exists in the furnace cavity, the intermediate frequency power supply is started to heat up, the temperature is raised and maintained to the process temperature according to the process requirement, the temperature is reduced or cooled along with the furnace after the sintering process is finished, the whole sintering process is finished, thereby removing oxygen and other impurity elements of the blank, enabling the blank.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.