Insulated and heat-resistant medium frequency furnace

Abstract

This utility model relates to the field of medium-frequency induction furnace technology, specifically a heat-insulating medium-frequency furnace, comprising a furnace shell, a furnace lining disposed within the furnace shell, a porous ceramic fiber composite layer, an induction coil, and a nano-aerogel composite insulation board. The porous ceramic fiber composite layer includes a gradient porous ceramic layer, a high-temperature resistant ceramic fiber module layer disposed inside the gradient porous ceramic layer, and a heat-insulating column disposed between the gradient porous ceramic layer and the high-temperature resistant ceramic fiber module layer. The porous ceramic fiber composite layer and the nano-aerogel composite insulation board are respectively disposed inside and outside the induction coil. The porous ceramic fiber composite layer provides heat insulation for the furnace lining, thereby shielding the heat radiation generated by the molten metal inside the furnace lining that acts on the induction coil, preventing the induction coil from burning out. The nano-aerogel composite insulation board can shield the heat radiation acting on the furnace shell, significantly reducing the temperature of the furnace shell.

Description

Technical Field

[0001] This utility model relates to the field of medium-frequency induction furnace technology, specifically a heat-insulating medium-frequency furnace. Background Technology

[0002] When a medium-frequency induction furnace is operating, magnetic lines of force are generated both inside and outside the induction coil. These magnetic lines of force cut through the metal material placed inside the furnace lining, creating large eddy currents within the metal. Heat penetrates the lining and radiates outwards, causing the induction coil temperature to rise rapidly, and potentially even burning out. Existing medium-frequency induction furnaces have a furnace lining heat loss rate as high as 25%-35%, and frequent furnace starts lead to a surge in energy consumption. In existing technologies, single ceramic fibers or insulation boards are insufficient to balance mechanical strength and thermal insulation performance. Furthermore, the furnace shell also heats up, and this heat radiates outwards, increasing the ambient temperature for workers. Existing medium-frequency electric furnaces only have a heat insulation structure on one side (inner or outer side) of the induction coil, which fails to effectively shield the internal and external heat radiation of the medium-frequency electric furnace. For example, the existing patent with patent number CN202120524319.X discloses a medium-frequency electric furnace. The structure of the medium-frequency electric furnace from the outside to the inside consists of a stainless steel furnace shell, a composite high-temperature resistant coating, a medium-frequency copper coil, and a furnace lining (furnace chamber). Although the composite high-temperature resistant coating can shield the heat radiation acting on the furnace shell, it cannot effectively shield the heat radiation radiating outward from the furnace lining to the induction coil. Utility Model Content

[0003] The purpose of this invention is to provide a heat-insulating medium-frequency furnace to overcome the problems existing in the current equipment.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a heat-insulating medium-frequency furnace, comprising a furnace shell, a furnace lining disposed within the furnace shell, a porous ceramic fiber composite layer, an induction coil, and a nano-aerogel composite insulation board. The furnace lining, porous ceramic fiber composite layer, induction coil, and nano-aerogel composite insulation board are arranged sequentially from the inside to the outside inside the furnace shell. The porous ceramic fiber composite layer is disposed between the furnace lining and the induction coil, and the nano-aerogel composite insulation board is disposed between the induction coil and the furnace shell. The porous ceramic fiber composite layer includes a gradient porous ceramic layer, a high-temperature resistant ceramic fiber module layer disposed inside the gradient porous ceramic layer, and a heat-insulating column disposed between the gradient porous ceramic layer and the high-temperature resistant ceramic fiber module layer. The high-temperature resistant ceramic fiber module layer covers the outer periphery of the furnace lining, and the induction coil surrounds the outer periphery of the gradient porous ceramic layer.

[0005] Based on the above technical solution, the present invention can be further improved as follows: As a further improvement to the above technical solution, the outer side of the high-temperature resistant ceramic fiber module layer is bonded and fixed to the inner side of the heat insulation column, and the outer side of the heat insulation column is fastened to the gradient porous ceramic layer. The heat insulation column is made of aerogel and polymer materials through blending and modification, which has the advantage of high heat insulation performance.

[0006] As a further improvement to the above technical solution, the high-temperature resistant ceramic fiber module layer is made of alumina-silica fiber material, which has a high porosity of 65%, a thickness of 5-8 mm, and can withstand a high temperature of 1600℃; the gradient porous ceramic layer is made of zirconium oxide-magnesium oxide composite sintered body, with a pore size of 0.1-0.3 mm and a thermal conductivity ≤0.8 W / (m·K).

[0007] As a further improvement to the above technical solution, the induction coil is arranged in a spiral shape, the cross-section of the furnace shell is square, the furnace shell includes a furnace shell top plate, a furnace shell side wall and a furnace shell base, and the nano-aerogel composite insulation board is provided on the inner side of the furnace shell side wall, and the nano-aerogel composite insulation board is closely attached to the inner side of the furnace shell side wall.

[0008] As a further improvement to the above technical solution, a magnetic column is fitted on the outside of the induction coil. The upper and lower ends of the magnetic column are respectively connected to an upper magnetic shielding seat and a lower magnetic shielding seat. The inner side of the magnetic column corresponds to the shape of the induction coil. The lower magnetic shielding seat has a mounting groove in the center for accommodating the porous ceramic fiber composite layer.

[0009] As a further improvement to the above technical solution, multiple annular heat sinks are provided between the furnace shell sidewall and the magnetic column. The heat sinks are connected and fixed to the inner surface of the furnace shell sidewall by screws. The screws penetrate the nano-aerogel composite insulation board. The inner edge of the heat sink is close to the outer wall of the magnetic column. Multiple cold water channels are provided inside the heat sink. The outer wall of the furnace shell sidewall is provided with a water inlet pipe and a water outlet pipe that communicate with the cold water channels.

[0010] As a further improvement to the above technical solution, the heat-insulating medium-frequency furnace also includes a cooling pipe, which is spirally arranged and attached to the induction coil. The spiral direction of the cooling pipe is consistent with that of the induction coil, and the cooling pipe is connected to the water inlet pipe and the drain pipe.

[0011] As a further improvement to the above technical solution, the furnace shell is made of corrugated metal plate, the material of which is 316L stainless steel, and the furnace lining is made of aluminum-magnesium spinel material.

[0012] As a further improvement to the above technical solution, the nano-aerogel composite insulation board has a porosity of 90% and a thermal conductivity of 0.02 W / m·K.

[0013] The beneficial effects of this utility model are as follows: the porous ceramic fiber composite layer and the nano-aerogel composite insulation board are respectively disposed on the inner and outer sides of the induction coil. The porous ceramic fiber composite layer provides heat preservation and insulation for the furnace lining, effectively shielding the heat generated by the molten metal inside the furnace lining from being transferred to the outside of the furnace lining. This shields the thermal radiation generated by the molten metal inside the furnace lining that acts on the induction coil, preventing the induction coil from being burned out. The nano-aerogel composite insulation board can shield the thermal radiation acting on the furnace shell, significantly reducing the temperature of the furnace shell and lowering the ambient temperature of the working environment to below 30°C. Attached Figure Description

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] Figure 1 This is a schematic diagram of the structure of the heat-insulating medium-frequency furnace provided in a preferred embodiment of the present invention; Figure 2 yes Figure 1 Schematic diagram of the AA section structure; In the diagram: 1. Furnace shell; 11. Furnace shell top plate; 12. Furnace shell side wall; 13. Furnace shell base; 2. Porous ceramic fiber composite layer; 21. Gradient porous ceramic layer; 22. High-temperature resistant ceramic fiber module layer; 23. Insulation column; 3. Induction coil; 4. Furnace lining; 5. Cooling pipe; 6. Magnetic guide column; 71. Upper magnetic guide shielding seat; 72. Lower magnetic guide shielding seat; 8. Nano-aerogel composite insulation board; 9. Heat sink; 91. Cold water channel; 92. Water inlet pipe; 93. Drain pipe. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. These drawings are simplified schematic diagrams, which are only used to illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0017] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0018] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0019] like Figure 1 , Figure 2 As shown, a preferred embodiment of this utility model provides a heat-insulating medium-frequency furnace, including a furnace shell 1, a furnace lining 4 disposed within the furnace shell 1, a porous ceramic fiber composite layer 2, an induction coil 3, and a nano-aerogel composite insulation board 8. The furnace lining 4, the porous ceramic fiber composite layer 2, the induction coil 3, and the nano-aerogel composite insulation board 8 are arranged sequentially from the inside to the outside inside the furnace shell 1. The porous ceramic fiber composite layer 2 is disposed between the furnace lining 4 and the induction coil 3, and the nano-aerogel composite insulation board 8 is disposed between the induction coil 3 and the furnace shell 1. The porous ceramic fiber composite layer 2 includes a gradient porous ceramic layer 21, a high-temperature resistant ceramic fiber module layer 22 disposed inside the gradient porous ceramic layer 21, and a heat-insulating column 23 disposed between the gradient porous ceramic layer 21 and the high-temperature resistant ceramic fiber module layer 22. The high-temperature resistant ceramic fiber module layer 22 covers the outer periphery of the furnace lining 4, and the induction coil 3 surrounds the outer periphery of the gradient porous ceramic layer 21.

[0020] The furnace lining 4 is made of aluminum-magnesium spinel material, and the induction coil 3 is spirally arranged around the outer periphery of the porous ceramic fiber composite layer 2. The furnace shell 1 has a square cross-section and is made of corrugated metal plate made of 316L stainless steel. The corrugated structure of the metal plate compensates for thermal expansion stress through elastic deformation, avoiding structural deformation caused by temperature changes, while enhancing the overall mechanical strength. The furnace shell 1 includes a top plate 11, side walls 12, and a base 13. The nano-aerogel composite insulation board 8 installed on the inner side of the side wall 12 can effectively shield heat radiation, significantly reducing the temperature of the furnace shell 1 and lowering the ambient temperature to below 30°C. The nano-aerogel composite insulation board 8 has a porosity of 90% and a thermal conductivity of 0.02 W / m·K.

[0021] The porous ceramic fiber composite layer 2 is used to insulate and heat-insulate the furnace lining 4, slowing down the rate at which heat generated by the molten metal inside the furnace lining 4 is transferred to the outside, effectively mitigating temperature changes in the molten metal inside the furnace lining 4, and thus reducing energy consumption. The high-temperature resistant ceramic fiber module layer 22 is externally bonded and fixed to the inner side of the heat insulation column 23, while the outer side of the heat insulation column 23 is tightly secured to the gradient porous ceramic layer 21. This facilitates the interaction between the high-temperature resistant ceramic fiber module layer 22 and the gradient porous ceramic layer 21, enhancing the heat insulation effect. Furthermore, the heat insulation column 23 positioned between the high-temperature resistant ceramic fiber module layer 22 and the gradient porous ceramic layer 21 ensures structural stability and better double-layer insulation. The heat insulation column 23 is made of a blend modified from aerogel and polymer materials, offering high heat insulation performance.

[0022] In this embodiment, the high-temperature resistant ceramic fiber module layer 22 is made of alumina-silica (Al2O3-SiO2) fiber material, which has a high porosity of 65% and a thickness of 5-8 mm, and can withstand a high temperature of 1600℃; the gradient porous ceramic layer 21 is made of zirconium oxide-magnesium oxide (ZrO2-MgO) composite sintered body with a pore size of 0.1-0.3 mm and a thermal conductivity of ≤0.8 W / (m·K), which significantly reduces the thermal conductivity, so that the porous ceramic fiber composite layer 2 has properties such as high temperature resistance, good thermal stability and low thermal conductivity.

[0023] Preferably, a magnetically conductive column 6 is mounted on the outer side of the induction coil 3. The upper and lower ends of the magnetically conductive column 6 are connected to an upper magnetically conductive shielding seat 71 and a lower magnetically conductive shielding seat 72, respectively. The cross-section of the magnetically conductive column 6 is fan-shaped, and its inner side corresponds to the outer shape of the induction coil 3. The upper magnetically conductive shielding seat 71 is annular, and can be a single, integral ring or an assembled ring. The lower magnetically conductive shielding seat 72 can be circular, and can be a single, integral piece or an assembled piece. The lower magnetically conductive shielding seat 72 has a mounting groove in its center for accommodating the porous ceramic fiber composite layer 2. The magnetically conductive column 6, the upper magnetically conductive shielding seat 71, and the lower magnetically conductive shielding seat 72 are mainly made of soft magnetic ferrite with high permeability and low loss in high-frequency magnetic fields through sintering, bonding, and pressing. Alternatively, they can be made directly from magnetically conductive powder or high-resistivity soft magnetic materials with high permeability and low loss in high-frequency magnetic fields through sintering, bonding, and pressing. By surrounding the induction coil 3 with the magnetically conductive column 6, an external magnetic shielding circuit is formed for the induction coil 3. Combined with the shielding of the upper and lower magnetically conductive shielding seats 71 and 72, the magnetic lines of force generated by the induction coil 3 are shielded to a certain extent from induction heating through the furnace shell top plate 11, furnace shell side wall 12, and furnace shell base 13, thus reducing energy loss.

[0024] Preferably, multiple annular heat sinks 9 are provided between the furnace shell sidewall 12 and the magnetic column 6. The heat sinks 9 are made of thermally conductive metal material. The heat sinks 9 are connected and fixed to the inner surface of the furnace shell sidewall 12 by screws. The screws pass through the nano-aerogel composite insulation board 8. The inner edge of the heat sink 9 is close to the outer wall of the magnetic column 6. Multiple cold water channels 91 are provided inside the heat sink 9. The outer wall of the furnace shell sidewall 12 is provided with a water inlet pipe 92 and a water outlet pipe 93 that communicate with the cold water channels 91. The heat sink 9 is provided to facilitate heat exchange with the magnetic column 6. Cooling water enters the cold water channel 91 from the water inlet pipe 92. After the cold water completes the heat exchange, it is discharged from the water outlet pipe 93, thereby reducing the temperature of the magnetic column 6.

[0025] Preferably, the above-mentioned intermediate frequency furnace further includes a cooling pipe 5, which is spirally arranged and attached to the induction coil 3. The cooling pipe 5 is made of high temperature resistant material, and the spiral direction of the cooling pipe 5 is consistent with that of the induction coil 3. The cooling pipe 5 is connected to the water inlet pipe 92 and the drain pipe 93. The cooling pipe 5 is set to facilitate heat exchange with the induction coil 3 and prevent the induction coil 3 from melting due to its own overheating. Cooling water enters the cooling pipe 5 from the water inlet pipe 92. After the cold water completes the heat exchange, it is discharged from the drain pipe 93, which reduces the temperature of the induction coil 3. The water inlet pipe 92 and the drain pipe 93 are connected to the water tank and the water pump to form a water circulation.

[0026] When the aforementioned medium-frequency furnace starts working, the induction coil 3 generates a high-intensity magnetic field after current is applied. Utilizing the electrothermal effect and electromagnetic induction principle, the metal particles in the metal material inside the furnace lining 4 begin to heat up and melt. The porous ceramic fiber composite layer 2 provides insulation and heat protection for the furnace lining 4, effectively shielding the heat generated by the molten metal inside the furnace lining 4 from being transferred to the outside of the furnace lining 4, and effectively slowing down the temperature change of the molten metal inside the furnace lining 4, thereby reducing energy consumption. In addition, a nano-aerogel composite insulation board 8 is attached to the side wall 12 of the furnace shell. The nano-aerogel composite insulation board 8 can effectively shield heat radiation, significantly reducing the temperature of the furnace shell 1 and lowering the ambient temperature to below 30°C.

[0027] Any descriptions not covered in the above specific embodiments of this utility model belong to the well-known technology in the field, and can be implemented by referring to the well-known technology.

[0028] Based on the preferred embodiments of this utility model described above, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A heat-insulating medium-frequency furnace, characterized in that: The furnace includes a furnace shell, a furnace lining inside the furnace shell, a porous ceramic fiber composite layer, an induction coil, and a nano-aerogel composite insulation board. The furnace lining, porous ceramic fiber composite layer, induction coil, and nano-aerogel composite insulation board are arranged sequentially from the inside to the outside inside the furnace shell. The porous ceramic fiber composite layer is located between the furnace lining and the induction coil, and the nano-aerogel composite insulation board is located between the induction coil and the furnace shell. The porous ceramic fiber composite layer includes a gradient porous ceramic layer, a high-temperature resistant ceramic fiber module layer located inside the gradient porous ceramic layer, and a heat insulation column located between the gradient porous ceramic layer and the high-temperature resistant ceramic fiber module layer. The high-temperature resistant ceramic fiber module layer covers the outer periphery of the furnace lining, and the induction coil surrounds the outer periphery of the gradient porous ceramic layer.

2. The heat-insulating medium-frequency furnace according to claim 1, characterized in that: The high-temperature resistant ceramic fiber module layer is bonded and fixed to the outside of the heat insulation column and the heat insulation column is fastened to the gradient porous ceramic layer on the outside. The heat insulation column is made of aerogel and polymer materials through blending and modification, which has the advantage of high heat insulation performance.

3. The heat-insulating medium-frequency furnace according to claim 2, characterized in that: The high-temperature resistant ceramic fiber module layer is made of alumina-silica fiber material with a high porosity of 65% and a thickness of 5-8 mm, which can withstand a high temperature of 1600℃; the gradient porous ceramic layer is made of zirconium oxide-magnesium oxide composite sintered body with a pore size of 0.1-0.3 mm and a thermal conductivity ≤0.8 W / (m·K).

4. The heat-insulating medium-frequency furnace according to claim 3, characterized in that: The induction coil is arranged in a spiral shape, and the cross-section of the furnace shell is square. The furnace shell includes a furnace shell top plate, a furnace shell side wall and a furnace shell base. The nano-aerogel composite insulation board is provided on the inner side of the furnace shell side wall, and the nano-aerogel composite insulation board is closely attached to the inner side of the furnace shell side wall.

5. The heat-insulating medium-frequency furnace according to claim 4, characterized in that: The outer side of the induction coil is equipped with a magnetic column. The upper and lower ends of the magnetic column are connected to an upper magnetic shield and a lower magnetic shield, respectively. The inner side of the magnetic column corresponds to the shape of the induction coil. The lower magnetic shield has a mounting groove in the center for accommodating the porous ceramic fiber composite layer.

6. The heat-insulating medium-frequency furnace according to claim 5, characterized in that: Multiple annular heat sinks are provided between the furnace shell sidewall and the magnetic column. The heat sinks are connected and fixed to the inner surface of the furnace shell sidewall by screws. The screws pass through the nano-aerogel composite insulation board. The inner edge of the heat sink is close to the outer wall of the magnetic column. Multiple cold water channels are provided in the heat sink. The outer wall of the furnace shell sidewall is provided with a water inlet pipe and a water outlet pipe that communicate with the cold water channels.

7. The heat-insulating medium-frequency furnace according to claim 6, characterized in that: It also includes a cooling pipe, which is spirally arranged and attached to the induction coil. The spiral direction of the cooling pipe is consistent with that of the induction coil, and the cooling pipe is connected to the water inlet pipe and the drain pipe.

8. The heat-insulating medium-frequency furnace according to claim 4, characterized in that: The furnace shell is made of corrugated metal plate, which is made of 316L stainless steel, and the furnace lining is made of aluminum-magnesium spinel material.

9. The heat-insulating medium-frequency furnace according to claim 4, characterized in that: The nano-aerogel composite insulation board has a porosity of 90% and a thermal conductivity of 0.02 W / m·K.

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