High-temperature vacuum furnace with circulating cooling system

Abstract

The utility model discloses a high-temperature vacuum furnace with a circulating cooling system. The circulating cooling system is hermetically communicated with the high-temperature vacuum furnace; the furnace body is provided with a cold air backflow port, and the air outlet pipeline is communicated with the heat insulation layer through the cold air backflow port. The vacuum chamber is provided with a hearth air inlet communicated with the heat insulation layer and the hearth; the vacuum chamber is further provided with a hearth high-temperature gas extraction opening, and the inlet end of the gas inlet pipeline is communicated with the hearth through the high-temperature gas extraction opening. The cooling heat exchange assembly comprises a heat exchanger and a water-cooling motor fan; the backflow pipeline is provided with a first adjusting valve which is used for controlling connection and disconnection of the backflow pipeline and is adjustable in opening degree, and the air outlet pipeline is provided with a second adjusting valve which is used for controlling connection and disconnection of the air outlet pipeline and is adjustable in opening degree. According to the device, circulating cooling can be started when gas in the hearth is at a high temperature, and the service life is long.

Description

Technical Field

[0001] The utility model relates to the technical field of heat treatment equipment, in particular to a high-temperature vacuum furnace with a strong cooling system. Background Art

[0002] High temperature vacuum furnace is a furnace that heats workpieces at high temperatures in a vacuum environment, including vacuum sintering furnaces, vacuum soldering furnaces, etc. In the application process of high temperature vacuum furnaces, induction heating or resistance heating are often used for heating. Therefore, a large amount of heat will be generated during the heating process, causing the temperature in the furnace cavity to rise. The cooling method of vacuum furnaces usually adopts natural cooling, forced convection circulation cooling or liquid nitrogen cooling.

[0003] Natural cooling means turning off the heating system after the heating treatment and letting the furnace cool naturally to room temperature. This method is simple and economical, but the cooling speed is slow. For some processes that require extremely fast cooling, a liquid nitrogen cooling system can be used to inject liquid nitrogen into the furnace to quickly reduce the temperature, but this method consumes a lot of gas. Forced convection circulation cooling accelerates the cooling speed inside the vacuum furnace through forced convection of circulating air or inert gas (such as nitrogen), thereby shortening the cooling time. However, when the temperature inside the pipeline is too high, it is easy to damage the cooling system, resulting in a shorter mission life of the circulating cooling system. Utility Model Content

[0004] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide a high-temperature vacuum furnace with a circulating cooling system and a long service life.

[0005] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0006] A high-temperature vacuum furnace with a circulating cooling system, the high-temperature vacuum furnace comprising a furnace body and a vacuum chamber, a furnace chamber is arranged in the vacuum chamber, and a heat insulation layer is arranged between the furnace body and the vacuum chamber; the circulating cooling system comprises a cooling heat exchange component, the air inlet port of the cooling heat exchange component is connected to an air inlet pipeline for passing the furnace high-temperature gas into the cooling heat exchange component, the air outlet port of the cooling heat exchange component is connected to an air outlet pipeline for discharging the gas after cooling the cooling heat exchange component, and also comprises a reflux pipeline connecting the air inlet pipeline and the air outlet pipeline; it is characterized in that: the circulating cooling system is sealed and connected to the high-temperature vacuum furnace; the furnace A cold air return port is provided on the body, and the air outlet pipeline is connected with the heat insulation layer through the cold air return port; a furnace air inlet connecting the heat insulation layer and the furnace is provided on the vacuum chamber; a furnace high-temperature gas extraction port is also provided on the vacuum chamber, and the inlet end of the air inlet pipeline is connected with the furnace through the high-temperature gas extraction port; the cooling and heat exchange component includes a heat exchange pipeline, and a heat exchanger and a water-cooled motor fan are installed in series on the heat exchange pipeline; a first regulating valve for controlling the on-off of the return pipeline and having an adjustable opening is provided on the return pipeline, and a second regulating valve for controlling the on-off of the outlet pipeline and having an adjustable opening is provided on the outlet pipeline.

[0007] As a further improvement of the above solution:

[0008] It also includes an insulated pipe, one end of which is sealed with the furnace body and the other end is connected to the vacuum chamber, the furnace high-temperature gas extraction port is located in the insulated pipe, a graphite lined tube is provided on the furnace high-temperature gas extraction port, the air inlet port of the air inlet pipeline is sealed with the graphite lined tube, and the inner wall of the insulated pipe and the air inlet pipeline are filled with insulating material.

[0009] The heat-insulating pipe comprises a protruding portion protruding out of the furnace body, and the air inlet port of the return pipeline is located in the protruding portion; a heat exchange water jacket is arranged on the periphery of the protruding portion, and a circulatable low-temperature heat exchange medium is arranged inside the heat exchange water jacket.

[0010] The outer peripheries of the air inlet pipeline, the air outlet pipeline, the return pipeline and the heat exchange pipeline are all provided with water exchange water jackets.

[0011] The air intake pipeline is provided with a first temperature detection device which can detect the temperature of the gas inside the pipeline.

[0012] The heat exchange pipeline is provided with a second temperature detection device which can detect the temperature of the gas inside the pipeline.

[0013] The high-temperature vacuum furnace is horizontal, the cold air return port is arranged at the top of the furnace body, and the furnace air inlet is arranged at the bottom of the vacuum chamber.

[0014] The furnace air inlets are provided with a plurality of air inlets evenly distributed along the length direction of the vacuum chamber.

[0015] Compared with the prior art, the advantages of the utility model are:

[0016] The utility model proposes a high-temperature vacuum furnace with a circulating cooling system. The device can start circulating cooling when the gas in the furnace is at a high temperature. By adjusting the opening of the first regulating valve and the second regulating valve, the gas in each pipeline of the circulating cooling system can be kept at a suitable low temperature state, avoiding damage to the pipeline, sealing components and heat exchanger, and extending their service life. The cooling rate can be adjusted by the wind speed of the first regulating valve, the second regulating valve and the water-cooling motor fan, and the adjustment is convenient and flexible. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the structure of a high-temperature vacuum furnace with a circulating cooling system in an embodiment.

[0018] Figure 2 Schematic diagram of the structure of the high temperature vacuum furnace in the embodiment.

[0019] The symbols in the figure represent:

[0020] 1. High-temperature vacuum furnace; 11. Furnace body; 12. Vacuum chamber; 13. Furnace; 14. Insulation layer; 15. Cold air return port; 16. Furnace air inlet; 17. Furnace high-temperature gas extraction port; 18. Graphite lined pipe; 19. Air supply port; 2. Circulating cooling system; 21. Heat exchanger; 22. Heat exchange pipeline; 221. Second temperature detection device; 23. Water-cooled motor fan; 24. Air inlet pipeline 241. First temperature detection device; 25. Air outlet pipeline; 251. Second regulating valve; 26. Return pipeline; 261. First regulating valve; 27. Heat exchange water jacket; 3. Insulation pipeline; 31. Protrusion; 32. Insulation material; 4. Sealing component. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0022] Figure 1 and Figure 2An embodiment of a high-temperature vacuum furnace with a circulating cooling system of the utility model is shown, wherein the high-temperature vacuum furnace 1 comprises a furnace body 11 and a vacuum chamber 12, wherein a furnace chamber 13 is provided in the vacuum chamber 12, and a heat insulating layer 14 is provided between the furnace body 11 and the vacuum chamber 12; the circulating cooling system 2 comprises a cooling heat exchange component, wherein an air inlet port of the cooling heat exchange component is connected to an air inlet pipeline 24 for passing the furnace high-temperature gas into the cooling heat exchange component, and an air outlet port of the cooling heat exchange component is connected to an air outlet pipeline 25 for discharging the gas after cooling the cooling heat exchange component, and further comprises a reflux pipeline 26 connecting the air inlet pipeline 24 and the air outlet pipeline 25; the circulating cooling system 2 is sealed and connected to the high-temperature vacuum furnace 1; a furnace chamber 13 is provided on the furnace body 1 ... pipeline 24 for passing the furnace high-temperature gas into the cooling heat exchange component, and the air outlet port of the cooling heat exchange component is connected to an air outlet pipeline 25 for discharging the gas after cooling the cooling heat exchange component, There is a cold air return port 15, and the air outlet pipeline 25 is connected to the heat insulation layer 14 through the cold air return port 15; the vacuum chamber 12 is provided with a furnace air inlet 16 connecting the heat insulation layer 14 and the furnace 13; the vacuum chamber 12 is also provided with a furnace high-temperature gas extraction port 17, and the inlet end of the air inlet pipeline 24 is connected to the furnace 13 through the high-temperature gas extraction port; the cooling heat exchange component includes a heat exchange pipeline 22, and the heat exchanger 21 and the water-cooled motor fan 23 are installed in series on the heat exchange pipeline 22; the return pipeline 26 is provided with a first regulating valve 261 for controlling the on and off of the return pipeline 26 and the opening is adjustable, and the air outlet pipeline 25 is provided with a second regulating valve 251 for controlling the on and off of the air outlet pipeline 25 and the opening is adjustable. In this structure, when there is ultra-high temperature gas above about 1800°C in the furnace 13, the circulating cooling system 2 starts to cool down, and the working principle is as follows:

[0023] Step 1: First, close the second regulating valve 251, open the first regulating valve 261 and the water-cooled motor fan 23, and allow the gas to circulate between the air intake pipe 24, the heat exchanger 21, the heat exchange pipe 22, and the return pipe 26. Because the second regulating valve 251 is in a closed state, no external gas enters the furnace 13, and the high-temperature gas inside the furnace 13 is in a relatively stable state, and will not flow out in large quantities from the furnace high-temperature gas extraction port 17, so that the gas temperature in this circulation pipe is always maintained at a relatively low temperature.

[0024] Step 2, open the second regulating valve 251 with a small opening. At this time, a small amount of low-temperature gas will flow from the outlet pipe 25 to the insulation layer 14, and a small amount of gas in the insulation layer 14 will pass into the furnace 13 from the furnace air inlet 16. A small amount of higher-temperature gas in the furnace 13 will flow out from the air inlet pipe 24, merge with the lower-temperature gas in the air inlet pipe 24, and then enter the heat exchanger 21, pass through the heat exchange pipe 22 and the air inlet pipe 24, and finally re-enter the furnace 13. This cycle is repeated to gradually reduce the temperature in the furnace 13.

[0025] Step 3: As the gas in the furnace 13 gradually decreases, the opening of the second regulating valve 251 is gradually increased and the opening of the first regulating valve 261 is reduced to increase the convection between the airflow and the material in the furnace.

[0026] Step 4: As the temperature in the furnace further decreases, the first regulating valve 261 is closed and the second regulating valve 251 is fully opened to perform large-flow convection heat exchange on the materials in the furnace. In addition, a gas replenishment port 19 is provided on the furnace body. As the gas in the furnace cools, the gas contracts, and gas can be replenished from the gas replenishment port 19 to maintain the pressure in the furnace, so that there is sufficient gas circulation in the furnace 13 to ensure heat exchange efficiency.

[0027] This device can start circulating cooling when the gas in the furnace 13 is at a high temperature. By adjusting the opening of the first regulating valve 261 and the second regulating valve 251, the gas in each pipeline of the circulating cooling system 2 can be kept at a suitable low temperature state, avoiding damage to the pipeline, the sealing component 4 and the heat exchanger 21, and extending their service life. The cooling rate can be adjusted by the wind speed of the first regulating valve 261, the second regulating valve 251 and the water-cooling motor fan 23, and the adjustment is convenient and flexible.

[0028] In this embodiment, the heat-insulated pipe 3 is also included, one end of which is sealed and connected to the furnace body 11 and the other end is connected to the vacuum chamber 12. The furnace high-temperature gas extraction port 17 is located in the heat-insulated pipe 3, and a graphite lining pipe 18 is provided on the furnace high-temperature gas extraction port 17. The air inlet port of the air inlet pipeline 24 is sealed and connected to the graphite lining pipe 18. The inner wall of the heat-insulated pipe 3 and the air inlet pipeline 24 are filled with heat-insulating material 32. In this structure, the heat-insulating material 32 can be made of refractory carbon felt, and the air inlet pipeline 24 located inside the heat-insulating layer 14 is protected by providing the graphite lining pipe 18 and the heat-insulated pipe 3 to prevent it from being damaged by the high-temperature environment.

[0029] In this embodiment, the heat-insulated pipe 3 includes a protruding portion 31 protruding from the outside of the furnace body 11, and the air inlet port of the return pipe 26 is located in the protruding portion 31; a water exchange water jacket 27 is provided on the periphery of the protruding portion 31, and a low-temperature heat exchange medium that can circulate is provided inside the water exchange water jacket 27. In this structure, because the temperature of the cold gas to be exchanged and the pipe near the high-temperature gas extraction port 17 of the furnace is relatively high, this part of the pipe is arranged in the heat-insulated pipe 3 for protection, and at the same time, a water exchange water jacket 27 is arranged outside the heat-insulated pipe 3 to cool it down, thereby protecting the sealing component 4 near the heat-insulated pipe 3 and the internal air exchange pipe.

[0030] In this embodiment, the outer peripheries of the inlet pipe 24, the outlet pipe 25, the return pipe 26 and the heat exchange pipe 22 are all provided with a heat exchange water jacket 27, and the interior of the heat exchange water jacket 27 is provided with a low-temperature heat exchange medium that can circulate. In this structure, each pipeline is sealed and connected through the sealing component 4. By providing the heat exchange water jacket 27 on the outside of each ventilation pipe, the temperature of the pipe and the sealing connection is reduced, the service life of the sealing component 4 is greatly increased, and the vacuum sealing performance is guaranteed.

[0031] In this embodiment, the air intake pipe 24 is provided with a first temperature detection device 241 capable of detecting the temperature of the gas inside the pipe. In this structure, the first temperature detection device 241 is provided to prevent the heat exchanger 21 from being damaged by excessively high temperature (about 600° C. or above) of the gas flowing through it. If the detected temperature is too high, the second regulating valve 251 is closed, and if the temperature is too low, the second regulating valve 251 is opened.

[0032] In this embodiment, the heat exchange pipeline 22 is provided with a second temperature detection device 221 capable of detecting the temperature of the gas inside the pipeline. With this structure, it is convenient to confirm the heat exchange effect of the heat exchanger 21 according to the gas temperature at the outlet of the heat exchanger 21 and monitor the entire circulating cooling system 2.

[0033] In this embodiment, the high temperature vacuum furnace 1 is horizontal, the cold air return port 15 is arranged at the top of the furnace body 11, and the furnace air inlet 16 is arranged at the bottom of the vacuum chamber 12. Through this structure, the relatively low temperature gas introduced at the cold air return port 15 can flow through the periphery of the vacuum chamber 12 and then enter the furnace 13, thereby improving the cooling efficiency.

[0034] In this embodiment, the furnace air inlets 16 are provided with a plurality of inlets 16 evenly spaced along the length direction of the vacuum chamber 12. This structure facilitates further improving the cooling efficiency.

[0035] Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the art can use the above disclosed technical content to make many possible changes and modifications to the technical solution of the present invention without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention should fall within the scope of protection of the technical solution of the present invention.

Claims

1. A high-temperature vacuum furnace with a circulating cooling system, comprising a high-temperature vacuum furnace (1) and a circulating cooling system (2), wherein the high-temperature vacuum furnace (1) comprises a furnace body (11) and a vacuum chamber (12), wherein a furnace (13) is provided in the vacuum chamber (12), and a heat insulating layer (14) is provided between the furnace body (11) and the vacuum chamber (12); wherein the circulating cooling system (2) comprises a cooling heat exchange component, wherein an air inlet port of the cooling heat exchange component is connected to an air inlet pipeline (24) for passing high-temperature gas from the furnace into the cooling heat exchange component, and an air outlet port of the cooling heat exchange component is connected to an air outlet pipeline (25) for discharging gas after cooling the cooling heat exchange component, and further comprises a reflux pipeline (26) connecting the air inlet pipeline (24) and the air outlet pipeline (25); wherein the circulating cooling system (2) comprises a cooling heat exchange component, wherein the cooling heat exchange component ... The circulating cooling system (2) is in sealed communication with the high-temperature vacuum furnace (1); the furnace body (11) is provided with a cold air return port (15), and the air outlet pipeline (25) is connected to the heat insulation layer (14) through the cold air return port (15); the vacuum chamber (12) is provided with a furnace air inlet (16) that connects the heat insulation layer (14) and the furnace (13); the vacuum chamber (12) is also provided with a furnace high-temperature gas extraction port (17), and the inlet end of the air inlet pipeline (24) is connected to the heat insulation layer (14) and the furnace (13) through the high-temperature gas extraction port (17). The warm gas extraction port is in communication with the furnace (13); the cooling heat exchange component comprises a heat exchange pipeline (22), on which a heat exchanger (21) and a water-cooled motor fan (23) are installed in series; the return pipeline (26) is provided with a first regulating valve (261) for controlling the on-off of the return pipeline (26) and having an adjustable opening; the outlet pipeline (25) is provided with a second regulating valve (251) for controlling the on-off of the outlet pipeline (25) and having an adjustable opening.

2. The high temperature vacuum furnace with a circulating cooling system according to claim 1, characterized in that: It also includes an insulated pipe (3), one end of which is sealedly connected to the furnace body (11) and the other end is connected to the vacuum chamber (12); the furnace high-temperature gas extraction port (17) is located in the insulated pipe (3); a graphite lined tube (18) is provided on the furnace high-temperature gas extraction port (17); the air inlet port of the air inlet pipeline (24) is sealedly connected to the graphite lined tube (18); and an insulating material (32) is filled between the inner wall of the insulated pipe (3) and the air inlet pipeline (24).

3. The high temperature vacuum furnace with a circulating cooling system according to claim 2, characterized in that: The heat-insulating pipe (3) comprises a protruding portion (31) protruding out of the furnace body (11), and the air inlet port of the return pipeline (26) is located in the protruding portion (31); a heat exchange water jacket (27) is provided on the outer periphery of the protruding portion (31), and a low-temperature heat exchange medium that can circulate is provided inside the heat exchange water jacket (27).

4. The high temperature vacuum furnace with a circulating cooling system according to claim 3, characterized in that: The outer circumferences of the air inlet pipeline (24), the air outlet pipeline (25), the return pipeline (26) and the heat exchange pipeline (22) are all provided with a heat exchange water jacket (27).

5. The high temperature vacuum furnace with a circulating cooling system according to claim 4, characterized in that: The air intake pipeline (24) is provided with a first temperature detection device (241) capable of detecting the temperature of the gas inside the pipeline.

6. The high temperature vacuum furnace with a circulating cooling system according to claim 5, characterized in that: The heat exchange pipeline (22) is provided with a second temperature detection device (221) capable of detecting the temperature of the gas inside the pipeline.

7. The high temperature vacuum furnace with a circulating cooling system according to claim 1, characterized in that: The high-temperature vacuum furnace (1) is horizontal, the cold air return port (15) is arranged at the top of the furnace body (11), and the furnace air inlet (16) is arranged at the bottom of the vacuum chamber (12).

8. The high temperature vacuum furnace with a circulating cooling system according to claim 7, characterized in that: A plurality of furnace air inlets (16) are provided, which are evenly spaced and distributed along the length direction of the vacuum chamber (12).

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