Air-cooled silicon carbide ceramic sintering furnace

Abstract

The utility model relates to an air cooling type silicon carbide ceramic sintering furnace in the field of sintering furnace equipment. A crucible inner container is arranged in a furnace body shell, a heat preservation layer is arranged outside the crucible inner container, an air cooling interlayer is reserved between the crucible inner container and the heat preservation layer, and a heater is arranged on the outer side of the crucible inner container. The air cooling system comprises a circulating fan, an air outlet of the circulating fan is in through connection with the air cooling interlayer through an air inlet pipeline, and the air cooling interlayer is connected to an air inlet of the circulating fan through an exhaust pipeline; the water cooling system comprises a heat exchange coil arranged in the air cooling interlayer and a shell-and-tube heat exchanger arranged outside the furnace body shell, the two ends of the heat exchange coil are communicated with a tube pass of the shell-and-tube heat exchanger in a circulating mode through a first water pump, and the external water tank is communicated with a shell pass of the shell-and-tube heat exchanger in a circulating mode through a second water pump. The sintering furnace adopts a cooling mode combining direct air cooling and indirect water cooling, so that the sintering cooling speed is effectively increased on the premise of ensuring the sintering effect, and the sintering efficiency and the sintering quality of silicon carbide ceramics are favorably improved.

Description

Technical Field

[0001] The utility model belongs to the field of sintering furnace equipment, and in particular relates to an air-cooled silicon carbide ceramic sintering furnace. Background Art

[0002] Silicon carbide ceramics are widely used in machinery, electronics, chemical industry, energy, environmental protection and other industries due to their excellent properties such as high temperature strength, good wear resistance, small thermal expansion coefficient, high hardness, resistance to thermal shock, and chemical corrosion. The preparation of silicon carbide ceramics mainly adopts sintering process, and the production equipment needs to use sintering furnace. Most of the existing silicon carbide sintering furnaces still use natural cooling, which takes a long time to cool down, making the production efficiency of silicon carbide ceramic products low; in order to speed up the sintering cooling speed, air-cooled silicon carbide sintering furnaces have appeared, but the air-cooling cooling rate is still slow, and the air-cooling effect is not ideal; in order to further speed up the sintering cooling speed, some silicon carbide sintering furnaces use water cooling, but direct water cooling is prone to sudden cooling, which may cause cracks in silicon carbide ceramics, thereby causing product quality risks. Utility Model Content

[0003] In view of the above situation, the utility model provides an air-cooled silicon carbide ceramic sintering furnace, which can effectively improve the cooling speed of the silicon carbide sintering furnace while ensuring the sintering effect of the silicon carbide ceramic.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] An air-cooled silicon carbide ceramic sintering furnace comprises a sintering furnace body, an air cooling system and a water cooling system. The sintering furnace body comprises a horizontal tank-shaped furnace shell, and a crucible liner coaxially sleeved in the middle of the furnace shell, a switchable furnace cover is arranged at the front end of the furnace shell, the bottom of the furnace shell is arranged above a fixed base through tank support legs, an outer jacket of the crucible liner is provided with an insulation layer, an air-cooling interlayer is reserved between the crucible liner and the insulation layer, and a heater is arranged on the outside of the crucible liner.

[0006] The air cooling system comprises a circulating fan, an air outlet of the circulating fan is connected to the air cooling interlayer through an air inlet pipeline, and the air cooling interlayer is connected to the air inlet of the circulating fan through an exhaust pipeline.

[0007] The water cooling system includes a heat exchange coil spirally wound in an air-cooled interlayer, a shell and tube heat exchanger arranged on the outside of the furnace body shell, and an external water tank arranged above the fixed base. The water inlet and outlet at both ends of the heat exchange coil are connected to the tube side circulation of the shell and tube heat exchanger through the water inlet and outlet pipes and water pump 1, and the external water tank is connected to the shell side circulation of the shell and tube heat exchanger through the upper water pipe, the return water pipe and water pump 2.

[0008] Furthermore, the furnace body shell is also provided with an exhaust interface, and the exhaust interface is connected to a vacuum pump through an exhaust pipeline for evacuating the interior of the sintering furnace body.

[0009] Furthermore, a gas charging interface is also provided on the furnace body shell, and the gas charging interface is connected to an external gas charging system through a gas charging pipeline, so as to charge inert gas into the sintering furnace body.

[0010] Furthermore, a pressure relief port is provided on the furnace shell, and a safety valve is installed on the pressure relief port to ensure that the furnace pressure is reliably controlled within a specific range.

[0011] Furthermore, the air intake pipeline includes a plurality of air distribution pipelines connected to the bottom of the air-cooled interlayer, and the air outlet of the circulation fan is connected to each air distribution pipeline through an air intake main pipe.

[0012] Furthermore, the exhaust pipeline includes a plurality of return air branch pipes connected to the top of the air-cooled interlayer, and each return air branch pipe is connected to the air inlet of the circulation fan through an air collecting main pipe.

[0013] Furthermore, the heat-insulating layer is coaxially mounted inside the furnace shell via a heat-insulating support. The crucible liner is coaxially mounted inside the furnace shell via a crucible support.

[0014] Furthermore, the furnace cover is a side-opening door structure, one side of the furnace cover is rotatably connected to the furnace body shell through a hinge, and the other side of the furnace cover is openably and closably connected to the furnace body shell through a lock.

[0015] Furthermore, a temperature sensor and a pressure sensor are arranged on the inner liner of the crucible, an electric control box is arranged above the fixed base through a support rod, and the temperature sensor, pressure sensor, circulating fan, water pump 1, water pump 2 and vacuum pump are all electrically connected to the electric control box.

[0016] The present invention also includes other components that enable it to be used normally, which are all conventional means in the field. In addition, devices or components not limited in the present invention, such as: temperature sensors, pressure sensors, circulating fans, heat exchange coils, shell and tube heat exchangers, water pump 1, water pump 2, vacuum pumps, inflation systems, and electrical control boxes and their internal control circuit settings, etc., all adopt the existing technologies in the field.

[0017] The beneficial effects of the utility model are as follows:

[0018] The utility model provides an air-cooled silicon carbide ceramic sintering furnace, which adopts a combination of direct air cooling and indirect water cooling. The air cooling directly cools the silicon carbide ceramic sintering furnace, and the water cooling indirectly cools the air cooling medium, thereby accelerating the cooling of the silicon carbide ceramic sintering furnace by lowering the temperature of the air cooling medium. Under the premise of ensuring the sintering effect of the silicon carbide ceramic, the sintering cooling speed of the silicon carbide sintering furnace is effectively improved, and the sintering efficiency and sintering quality of the silicon carbide ceramic are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the structure of the air-cooled silicon carbide ceramic sintering furnace in the embodiment. DETAILED DESCRIPTION

[0020] The technical solution of the present utility model will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, rather than all embodiments.

[0021] It should be noted that the terms "upper", "lower", "front", "back", "inside", "outside" and the like indicating directions or positional relationships are based on the drawings and are for the convenience of description only.

[0022] Example

[0023] like Figure 1 As shown, an air-cooled silicon carbide ceramic sintering furnace includes a sintering furnace body, an air cooling system and a water cooling system. The sintering furnace body includes a horizontal tank-shaped furnace body shell 1, and a crucible liner 2 coaxially sleeved in the middle of the furnace body shell. A switchable furnace cover 3 is provided at the front end of the furnace body shell. The furnace cover is a side-opening door structure. One side of the furnace cover is rotatably connected to the furnace body shell by a hinge (not shown in the figure), and the other side is openably and closably connected to the furnace body shell by a lock 4.

[0024] The bottom of the furnace shell is erected above the fixed base 6 through the tank support feet 5, the outer jacket of the crucible inner liner is provided with an insulation layer 7, an air-cooling interlayer 8 is left between the crucible inner liner and the insulation layer, and a heater 9 is arranged on the outside of the crucible inner liner, and the heater is an induction heating coil; the insulation layer is coaxially erected inside the furnace shell through the insulation support 10; the crucible inner liner is coaxially erected inside the furnace shell through the crucible support 11.

[0025] The air cooling system includes a circulating fan 12, the air outlet of the circulating fan is connected to the air cooling interlayer through an air intake pipeline, and the air cooling interlayer is connected to the air inlet of the circulating fan through an exhaust pipeline. The air intake pipeline includes five air distribution pipelines 13 connected to the bottom of the air cooling interlayer, and the air outlet of the circulating fan is connected to each air distribution pipeline through an air intake main pipe 14. The exhaust pipeline includes seven return air branch pipes 15 connected to the top of the air cooling interlayer, and each return air branch pipe is connected to the air inlet of the circulating fan through an air collecting main pipe 16.

[0026] The water cooling system includes a heat exchange coil 17 spirally wound in an air-cooled interlayer, a shell and tube heat exchanger 18 arranged on the outside of the furnace body shell, and an external water tank 19 arranged above the fixed base. The water inlet and outlet at both ends of the heat exchange coil are connected to the tube side circulation of the shell and tube heat exchanger through the inlet and outlet pipes and water pump 1 20, and the external water tank is connected to the shell side circulation of the shell and tube heat exchanger through the upper water pipe, the return water pipe and the water pump 2 21.

[0027] The furnace body shell is also provided with an exhaust interface, which is connected to a vacuum pump 22 through an exhaust pipeline for exhausting a vacuum inside the sintering furnace body.

[0028] The furnace body shell is also provided with an inflation interface, which is connected to an inflation system 23 through an inflation pipe. The inflation system includes a gas source, an inflation valve assembly and an inflation pipe assembly. The specific configuration is the same as the inflation system disclosed in patent document CN211147276U, an air-cooled silicon carbide ceramic sintering furnace. The existing technology is adopted and the details are not repeated here. The sintering furnace body can be quantitatively charged with inert gas to provide atmosphere protection during the sintering of silicon carbide ceramics. Generally, nitrogen protection or argon protection is commonly used.

[0029] The furnace shell is also provided with a pressure relief port, on which a safety valve 24 is installed to ensure that the furnace pressure is reliably controlled within a safe range.

[0030] The crucible inner shell is provided with a temperature sensor 25 and a pressure sensor 26, and an electric control box 28 is mounted on the fixed base through a support rod 27. The temperature sensor, pressure sensor, circulating fan, water pump 1, water pump 2 and vacuum pump are all electrically connected to the electric control box. The electric control box and its internal control circuit are both configured using existing technologies, and the details are not repeated here.

[0031] When the air-cooled silicon carbide ceramic sintering furnace is used, the silicon carbide ceramic blank is first placed in the crucible inner liner, the furnace cover is sealed and closed, the furnace body is evacuated, and then the protective gas is filled into the furnace body. Then, the crucible inner liner is induction heated. After the silicon carbide ceramic is sintered, the circulating fan is turned on to force the protective gas to circulate in the furnace body to take away the heat inside the furnace body, thereby achieving an air-cooling effect. At the same time, the water pump 1 is started to force the cooling water in the heat exchange coil to flow to cool the flowing protective gas. At the same time, the water pump 2 is started to use the circulating water in the external water tank through the shell and tube heat exchanger to exchange heat and cool the cooling water in the heat exchange coil, thereby indirectly promoting the cooling and cooling of the protective gas airflow by the cooling water in the heat exchange coil, improving the air-cooling efficiency of the sintering furnace, and thereby achieving rapid cooling of the sintered silicon carbide ceramic.

[0032] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. Without departing from the scope and spirit of the described embodiments, many modifications and changes are obvious to ordinary technicians in this technical field. Any technical deformation made within the spirit and principles of the present invention falls within the protection scope of the present invention.

Claims

1. An air-cooled silicon carbide ceramic sintering furnace, comprising a sintering furnace body, an air cooling system and a water cooling system, characterized in that: The sintering furnace body comprises a horizontal can-shaped furnace shell, and a crucible liner coaxially sleeved in the middle of the furnace shell, a switchable furnace cover is arranged at the front end of the furnace shell, the bottom of the furnace shell is arranged above the fixed base through the can support legs, the outer jacket of the crucible liner is provided with an insulation layer, an air-cooling interlayer is reserved between the crucible liner and the insulation layer, and a heater is arranged on the outside of the crucible liner; the air cooling system comprises a circulating fan, the air outlet of the circulating fan is connected to the air-cooling interlayer through an air inlet pipeline The air-cooled interlayer is connected to the air inlet of the circulating fan through the exhaust pipe; the water cooling system includes a heat exchange coil spirally wound in the air-cooled interlayer, a shell and tube heat exchanger arranged on the outside of the furnace body shell, and an external water tank arranged above the fixed base, the water inlet and outlet at both ends of the heat exchange coil are connected to the tube side circulation of the shell and tube heat exchanger through the water inlet and outlet pipes and water pump 1, and the external water tank is connected to the shell side circulation of the shell and tube heat exchanger through the upper water pipe, the return water pipe and water pump 2.

2. The air-cooled silicon carbide ceramic sintering furnace according to claim 1, characterized in that: The furnace body shell is also provided with an exhaust interface, which is connected to a vacuum pump through an exhaust pipeline and is used for exhausting a vacuum inside the sintering furnace body.

3. The air-cooled silicon carbide ceramic sintering furnace according to claim 2, characterized in that: The furnace body shell is also provided with a gas charging interface, which is connected to an external gas charging system through a gas charging pipeline and is used to charge inert gas into the sintering furnace body.

4. The air-cooled silicon carbide ceramic sintering furnace according to claim 3, characterized in that: The furnace shell is also provided with a pressure relief port, and a safety valve is installed on the pressure relief port.

5. The air-cooled silicon carbide ceramic sintering furnace according to claim 1, characterized in that: The air inlet pipeline includes a plurality of air distribution pipelines connected to the bottom of the air-cooled interlayer, and the air outlet of the circulating fan is connected to each air distribution pipeline through an air inlet main pipe.

6. The air-cooled silicon carbide ceramic sintering furnace according to claim 1, characterized in that: The exhaust pipeline includes a plurality of return air branch pipes connected to the top of the air-cooled interlayer, and each return air branch pipe is connected to the air inlet of the circulation fan through an air collecting main pipe.

7. The air-cooled silicon carbide ceramic sintering furnace according to claim 1, characterized in that: The heat-insulating layer is coaxially mounted inside the furnace shell via a heat-insulating support.

8. The air-cooled silicon carbide ceramic sintering furnace according to claim 7, characterized in that: The crucible inner container is coaxially mounted inside the furnace shell through a crucible support.

9. The air-cooled silicon carbide ceramic sintering furnace according to claim 1, characterized in that: The furnace cover is a side-opening door structure, one side of the furnace cover is rotatably connected to the furnace body shell through a hinge, and the other side of the furnace cover is openably and closably connected to the furnace body shell through a lock.

10. The air-cooled silicon carbide ceramic sintering furnace according to claim 4, characterized in that: A temperature sensor and a pressure sensor are arranged on the inner liner of the crucible, an electric control box is arranged above the fixed base through a support rod, and the temperature sensor, pressure sensor, circulating fan, water pump 1, water pump 2 and vacuum pump are all electrically connected to the electric control box.

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