JP3907242B2 - High temperature heating method and apparatus for rod-shaped workpiece - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a high-temperature heating method and apparatus for a rod-shaped workpiece that heats a rod-shaped raw material to a high temperature of 1400 ° C. to 2500 ° C. in a non-oxidized state.
[0002]
[Prior art]
In order to heat non-ferrous materials such as ceramics and silicone to a high temperature of 1400 ° C. to 2500 ° C. (for example, about 2300 ° C.), a high temperature heating apparatus illustrated in FIG. 3 has been conventionally used. This high-temperature heating apparatus has a hollow cylindrical heating furnace 1 in which a hollow cylindrical tube 2, a heater 3, a heat insulating material 4, etc. are arranged substantially concentrically, and the heater 3 is heated by resistance heating. The inside of the heating furnace 1 is heated and held at a high temperature, and the rod-shaped object 6 (work) suspended from the suspension rod 5 is lowered along the axis of the heating furnace 1 to bring the work 6 to a predetermined temperature (for example, 1400). C. to 1700 [deg.] C.), and then the workpiece 6 is taken out below the heating furnace 1 and supplied to the next step. Such a high-temperature heating apparatus is characterized in that the bar-shaped workpiece 6 is sequentially supplied under atmospheric pressure, and the workpiece 6 heated at a high temperature can be processed as it is / or cooled in the next process, and has high operability. .
[0003]
In the high-temperature heating apparatus described above, carbon (for example, high-purity graphite) is used for the heater 3 and the heat insulating material 4 in order to enable use at a high temperature of 1400 ° C. to 2500 ° C. Further, in order to prevent oxidation of the carbon heater 3 and the carbon heat insulating material 4 at high temperatures, nitrogen gas is continuously purged into the heating furnace 1 to keep the inside of the heating furnace 1 at a positive pressure so that outside air does not flow. .
[0004]
[Problems to be solved by the invention]
In the above-described conventional high-temperature heating apparatus, the inside of the apparatus is purged with nitrogen gas (hereinafter simply referred to as N ₂ purge) before supplying the work to the apparatus. However, there is a problem that it is very difficult to completely replace the air (oxygen) in the heating furnace with nitrogen by this N ₂ purge.
[0005]
That is, there are openings through which the work 6 passes above and below the heating furnace 1, and even if the inside is purged with N ₂ as it is, it takes a long time to replace the air (O ₂ ) in the porous heat insulating material 4, If this replacement is performed completely, the operating rate (ie productivity) of the apparatus is greatly reduced.
Further, if the operation is performed with an incomplete N ₂ purge in order to increase the operating rate of the apparatus, the carbon material (carbon heater 3 and carbon heat insulating material 4) heated to a high temperature is oxidized by residual oxygen in the heating furnace. There was a problem of exhaustion.
[0006]
Further, this oxidation causes oxide impurities to adhere to the workpiece, lowering the quality of the workpiece, and requiring the removal work for removing the oxide, resulting in further deterioration in operability. Furthermore, in conventional high-temperature heating devices, carbon is oxidized (combusted) when released to the atmosphere at high temperatures, so it is necessary to cool the device for each operation, and as a result, it takes time to heat up / cool the device. There was a problem that the operating rate further decreased.
[0007]
The present invention has been made to solve such problems. That is, the main object of the present invention is to completely replace the air (oxygen) in the heating furnace with nitrogen in a short time, and in this state completely prevent the inflow of air, An object of the present invention is to provide a high-temperature heating method and apparatus for a bar-shaped workpiece that can be sequentially supplied below and a workpiece heated at a high temperature can be taken out. Another object of the present invention is to prevent the oxidation of the carbon material, extend the life of the carbon material, greatly reduce the consumption / replacement frequency of the carbon material, and sequentially supply workpieces while keeping the heater heated. Thus, an object of the present invention is to provide a high-temperature heating method and apparatus for a rod-shaped workpiece that can greatly increase the operating rate. Still another object of the present invention is to prevent the work quality from being deteriorated due to oxidation impurities, eliminate the work oxide removal work, and thereby improve the work quality without sacrificing productivity. It is to provide a heating method and apparatus.
[0008]
[Means for Solving the Problems]
According to the present invention, a high-temperature heating furnace having openings at the top and bottom and maintaining the inside at a high temperature by resistance heating, a suspension rod for suspending and lowering an object to be heated from the upper opening to the lower opening, and a high temperature A gas purge device that purges the inside of the heating furnace with an inert gas, an upper sealing device that hermetically surrounds the suspension rod and the object to be heated, and can be installed in the upper opening in an airtight manner, and an upper and lower opening that opens and closes the upper and lower openings in an airtight manner A sealing device and an evacuating device for evacuating the upper side of the upper sealing device are installed. An upper sealing device in which an object to be heated is set is hermetically attached to the upper opening, the lower sealing device is closed, and the upper sealing device is opened. In this state, the upper sealing device is evacuated together with the high temperature heating furnace, and then the high temperature heating furnace is heated while purging the inside of the high temperature heating furnace with an inert gas, the lower sealing device is opened, and the object to be heated is opened to the upper opening. From Lowering through the high temperature heating furnace until part opening, high-temperature heating method of the rod-shaped workpiece, characterized in that there is provided.
[0009]
According to the method of the present invention, since the inside of the high temperature heating furnace is purged with the inert gas after the upper sealing device is evacuated together with the high temperature heating furnace, the air (oxygen) in the heating furnace is completely inactivated in a short time. The high-temperature heating furnace is heated while completely preventing inflow of air by purging with an inert gas in this state and purging with an inert gas. Life can be extended. In this state, the lower seal device is opened, and the object to be heated is lowered from the upper opening to the lower opening through the high-temperature heating furnace, so that rod-shaped workpieces are supplied at atmospheric pressure while completely preventing the inflow of air. In addition, the workpiece heated at a high temperature can be taken out, and the deterioration of the workpiece quality due to the oxidation impurities can be prevented.
[0010]
According to a preferred embodiment of the present invention, the suspension rod is further raised, the upper sealing device is closed while maintaining the temperature of the high-temperature heating furnace, the upper sealing device is opened, the object to be heated is reset, and the upper sealing is performed. Reinstall the device in an airtight manner in the upper opening, evacuate the upper sealing device, and then purge with an inert gas to bring the high-temperature heating furnace to the same pressure, then open the upper sealing device and remove the object to be heated from the upper opening. Lower to lower opening through high temperature furnace. By this method, the temperature of the high-temperature heating furnace can be maintained, and the workpieces can be sequentially supplied while the heater is heated and held, thereby greatly increasing the operating rate.
[0011]
Further, according to the present invention, a high-temperature heating furnace having openings at the top and bottom and maintaining the inside at a high temperature by resistance heating, and a suspension rod for suspending and lowering an object to be heated from the upper opening to the lower opening, In a high-temperature heating apparatus for a rod-shaped workpiece provided with a gas purge device for purging the inside of a high-temperature heating furnace with an inert gas, an upper sealing device capable of hermetically surrounding the suspension rod and the object to be heated and vertically expanding and contracting, and an upper sealing device A rod driving device that lifts and lowers the suspension rod while expanding and contracting, an upper and lower sealing device that opens and closes the upper and lower openings airtightly, and an evacuation device that evacuates the upper side of the upper sealing device. A high-temperature heating apparatus for a rod-shaped workpiece, wherein the upper sealing device is evacuated together with the heating furnace, and then the high-temperature heating furnace is heated while purging the inside of the high-temperature heating furnace with an inert gas. It is provided.
[0012]
According to the configuration of the present invention described above, since the upper sealing device that surrounds the suspension rod and the object to be heated in an airtight manner and can be expanded and contracted is evacuated, the upper sealing device is evacuated together with the high temperature heating furnace, and then the inside of the high temperature heating furnace is After heating the high-temperature heating furnace while purging with an inert gas, the object to be heated can be lowered through the high-temperature heating furnace from the upper opening to the lower opening while the upper sealing device is contracted by the rod driving device. It is possible to eliminate the upward leakage completely, and to adjust the flow of the purge gas downward, thereby preventing the inflow of air and supplying the bar-shaped workpiece under atmospheric pressure and taking out the workpiece heated at high temperature. Can do.
[0013]
According to a preferred embodiment of the present invention, the upper sealing device is a telescopic device in which a plurality of hollow cylindrical members are fitted in an axially expandable and contractible manner. With this configuration, a relatively thin hollow cylindrical member can withstand the differential pressure during vacuum, the upper sealing device can be made lightweight, the degree of vacuum can be sufficiently increased, and air in the heating furnace can be replaced. It can be done more completely.
[0014]
The rod driving device includes a vertical ball screw and upper and lower nut driving devices for rotating and rotating upper and lower nuts screwed to the ball screw, and the upper nut driving device is an upper end of the suspension rod and the telescopic device. The lower nut driving device is connected to the lower end portion of the telescopic device. With this configuration, the upper nut is rotated by the upper nut driving device, so that the upper end of the hanging rod and the telescopic device can be raised and lowered simultaneously, and the hanging rod can be raised and lowered while extending and retracting the upper sealing device. By rotating the lower nut with the driving device, the lower end portion of the telescopic device is raised and lowered to open and close the lower portion of the upper sealing device, and the object to be heated can be set.
[0015]
The rod driving device further includes a swing device that swings the suspension rod and the upper sealing device about a vertical axis. With this configuration, the suspension rod and upper sealing device are swung, the upper part of the high-temperature heating furnace is opened, the object to be heated is transported above the upper opening by a crane or the like, and temporarily placed with an appropriate jig. The object to be heated can be easily set.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected and used for the common part in each figure.
FIG. 1 is an overall configuration diagram of a high-temperature heating apparatus according to the present invention. In this figure, a high-temperature heating apparatus 10 includes a high-temperature heating furnace 1 having openings 1a and 1b on the upper and lower sides and holding the inside at a high temperature by resistance heating, and an object to be heated 6 (from an upper opening 1a to a lower opening 1b ( A suspension rod 5 that suspends and lowers the workpiece) and a gas purge device 7 that purges the inside of the high-temperature heating furnace 1 with an inert gas (for example, nitrogen gas) are provided. A carbon heater 3 and a carbon heat insulating material 4 are built in the high-temperature heating furnace 1, and the heater 3 generates heat by resistance heating so that the inside of the heating furnace 1 is heated and held at a high temperature and is suspended by a suspension rod 5. The work 6 is lowered along the axis of the heating furnace 1 to heat the work 6 to a predetermined temperature (for example, 1400 ° C. to 1700 ° C.), and then the work 6 is taken out below the heating furnace 1 (not shown). ). Such a configuration is the same as that of the conventional high-temperature heating apparatus shown in FIG.
[0017]
The high-temperature heating device 10 of the present invention further includes an upper sealing device 12 that hermetically surrounds the suspension rod 5 and the object to be heated 6 (workpiece) and can be expanded and contracted vertically, and the suspension rod 5 is raised and lowered while the upper sealing device 12 is expanded and contracted. The rod drive device 14 includes upper and lower seal devices 16a and 16b that open and close the upper and lower openings 1a and 1b in an airtight manner, and a vacuum exhaust device 18 that evacuates the upper side of the upper seal device 16a.
[0018]
In FIG. 1, an upper sealing device 12 is a telescopic device in which a plurality of hollow cylindrical members 13 are fitted so as to be extendable and contractable in the axial direction. A vacuum sealing material is attached between the hollow cylindrical members 13 so as to keep airtight therebetween while sliding in the axial direction. With this configuration, the relatively thin hollow cylindrical member 13 can withstand the differential pressure during vacuum (about 760 mmAq), the upper sealing device 12 can be reduced in weight, and the degree of vacuum can be sufficiently increased. The replacement of air in 1 can be done completely.
[0019]
The rod driving device 14 includes a vertical ball screw 15a and upper and lower nut driving devices 19a and 19b for rotating and driving upper and lower ball nuts 15b and 15c screwed to the ball screw 15a, respectively. The upper nut driving device 19 a is connected to the upper end portion 5 a of the suspension rod 5 and the upper end portion 12 a of the telescopic device 12, and the lower nut driving device 19 b is connected to the lower end portion 12 b of the telescopic device 12.
[0020]
With this configuration, the upper nut 15b is rotated by the upper nut driving device 19a, so that the suspension rod 5 and the upper end portions 5a, 12a of the telescopic device 12 are simultaneously raised and lowered, and the suspension rod 5 is expanded and contracted. The lower nut 15c is rotated by the lower nut driving device 19b, whereby the lower end portion 12b of the telescopic device 12 is moved up and down to open and close the lower portion of the upper sealing device 12, and the workpiece 6 is easily set. be able to.
[0021]
As shown in FIG. 1, the rod driving device 14 further includes a swing device 20 that swings the suspension rod 5 and the upper sealing device 12 about a vertical axis Z spaced from the high-temperature heating furnace 1. The swing device 20 is configured to swing horizontally at a necessary angle (for example, 90 to 120 °) by a linear cylinder or the like (not shown). With this configuration, the suspension rod 5 and the upper sealing device 12 are swung horizontally, the upper portion of the high-temperature heating furnace 1 is opened, and the workpiece 6 is transported above the upper opening 1a by a crane or the like, and an appropriate jig is used. The workpiece 6 can be easily set.
[0022]
FIG. 2 is a process diagram showing a high-temperature heating method for a rod-shaped workpiece according to the present invention. In this figure, (A) shows a case where the first workpiece 6 is heated, and (B) shows a case where the second and subsequent workpieces 6 are heated.
[0023]
According to the method of the present invention, when the first workpiece 6 is heated (A), the workpiece is heated by the following operation procedure. (1) First, the upper sealing device 12 on which the workpiece 6 is set is airtightly attached to the upper opening 1a. (2) Next, as shown in FIG. 2A, the upper sealing device 12 is evacuated together with the high temperature heating furnace 1 with the lower sealing device 16b closed and the upper sealing device 16a opened. By this operation, the air (oxygen) in the heating furnace 1 can be completely replaced with an inert gas (nitrogen) in a short time.
(3) Next, heating of the high-temperature heating furnace 1 is started while purging the inside of the high-temperature heating furnace 1 with an inert gas. This operation heats the high-temperature heating furnace 1 while completely preventing the inflow of air by purging with an inert gas, so that the carbon material (the carbon heater 3 and the carbon heat insulating material 4) is prevented from being oxidized and the life of the carbon material is increased. Can be stretched.
(4) Next, the lower sealing device 16b is opened, and the work 6 is lowered from the upper opening 1a to the lower opening 1b through the high temperature heating furnace 1. Thereby, while preventing the inflow of air completely, the rod-shaped workpiece 6 can be supplied under atmospheric pressure, the workpiece 6 heated at a high temperature can be taken out from below, and the quality of the workpiece 6 can be prevented from being deteriorated due to oxidation impurities. it can.
[0024]
Next, in the case of heating the second and subsequent workpieces 6 (B), (5) as shown in FIG. 2A, the workpiece 6 taken out from below is supplied to the next step, and then the suspension rod 5 is moved. The upper sealing device 16a is closed while the temperature of the high-temperature heating furnace 1 is maintained. At this time, the lower opening 1b may be kept open and kept in a state in which the inflow of air is prevented by purging, but the lower opening 1b may be closed to stop the purge gas if necessary. (6) Next, the upper sealing device 12 is opened, the workpiece 6 is reset, the upper sealing device 12 is air-tightly reattached to the upper opening 1a, the upper sealing device 12 is evacuated, and then purged with an inert gas. Then, after the high pressure furnace is set to the same pressure, the upper seal device 16a is opened. By this operation, the workpiece 6 can be reset while maintaining the temperature of the high-temperature heating furnace 1 and completely preventing the inflow of air. (7) Next, the work 6 is lowered from the upper opening 1a to the lower opening 1b through the high temperature heating furnace 1, and the high temperature heated work 6 is taken out from below. According to this method, the temperature of the high-temperature heating furnace 1 can be maintained, and workpieces can be sequentially supplied while the heater is heated and held, thereby greatly increasing the operating rate.
[0025]
In addition, this invention is not limited to embodiment mentioned above, Of course, it can change variously in the range which does not deviate from the summary of this invention.
[0026]
【The invention's effect】
As described above, the high-temperature heating method and apparatus for a rod-shaped workpiece according to the present invention can: (1) The air (oxygen) in the heating furnace can be completely replaced with nitrogen in a short time, and the inflow of air in this state It is possible to supply bar-shaped workpieces sequentially under atmospheric pressure and take out the workpieces heated at high temperature, preventing the oxidation of carbon materials, extending the life of carbon materials, and exhausting carbon materials. / Replacement frequency can be greatly reduced, and workpieces can be supplied sequentially while the heater is heated. This can greatly increase the operating rate, and (3) prevent deterioration of workpiece quality due to oxidative impurities. There is an excellent effect such as eliminating the need for an object removal operation and thereby improving the quality of the workpiece without impairing the productivity.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a high-temperature heating apparatus according to the present invention.
FIG. 2 is a process diagram showing a high-temperature heating method for a rod-shaped workpiece according to the present invention.
FIG. 3 is a configuration diagram of a conventional high-temperature heating apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 High temperature heating furnace 1a, 1b Opening part 2 Tube 3 Heater (carbon heater)
4 Insulation (carbon insulation)
5 Hanging rod 6 Object to be heated (bar-shaped workpiece)
7 Gas purge device 10 High temperature heating device 12 Upper sealing device 13 Hollow cylindrical member 14 Rod drive device 15a Ball screws 15b, 15c Upper and lower ball nuts 16a, 16b Upper and lower seal devices 18 Vacuum exhaust devices 19a, 19b Upper and lower nut drive devices 20 Swing device

Claims (6)

A high-temperature heating furnace having openings at the top and bottom and holding the inside at a high temperature by resistance heating, a suspension rod for suspending and lowering the object to be heated from the upper opening to the lower opening, and inerting the inside of the high-temperature heating furnace A gas purging device for purging with gas; an upper sealing device that hermetically surrounds the suspension rod and the object to be heated; and an upper and lower sealing device that hermetically opens and closes the upper and lower openings; and an upper seal An evacuation device for evacuating the upper side of the device,
The upper sealing device with the object to be heated is airtightly attached to the upper opening, the lower sealing device is closed, the upper sealing device is opened, and the upper sealing device is evacuated together with the high temperature heating furnace, and then the high temperature heating furnace Heating the high-temperature heating furnace while purging the interior with an inert gas, opening the lower sealing device, and lowering the article to be heated from the upper opening to the lower opening through the high-temperature heating furnace. High temperature heating method. Furthermore, the suspension rod is raised, the upper sealing device is closed while maintaining the temperature of the high-temperature heating furnace, the upper sealing device is opened, the object to be heated is reset, and the upper sealing device is hermetically reattached to the upper opening. Then, the upper sealing device is evacuated and then purged with an inert gas to bring the high-temperature heating furnace to the same pressure. Then, the upper sealing device is opened, and the object to be heated is lowered from the upper opening to the lower opening through the high-temperature heating furnace. The high-temperature heating method for a bar-shaped workpiece according to claim 1, wherein: A high-temperature heating furnace having openings at the top and bottom and holding the inside at a high temperature by resistance heating, a suspension rod for suspending and lowering the object to be heated from the upper opening to the lower opening, and inerting the inside of the high-temperature heating furnace In a high-temperature heating device for a rod-shaped workpiece provided with a gas purge device for purging with gas,
An upper sealing device that hermetically surrounds the suspension rod and the object to be heated and can be vertically expanded, a rod drive device that raises and lowers the suspension rod while expanding and contracting the upper sealing device, and an upper and lower seal that opens and closes the upper and lower openings in an airtight manner And an evacuation device that evacuates the upper side of the upper seal device, thereby evacuating the upper sealing device together with the high-temperature heating furnace, and then purging the inside of the high-temperature heating furnace with an inert gas at a high temperature A high-temperature heating apparatus for a rod-shaped workpiece, characterized by heating a heating furnace. The high-temperature heating device for a bar-shaped workpiece according to claim 3, wherein the upper sealing device is a telescopic device in which a plurality of hollow cylindrical members are fitted so as to be extendable and contractable in the axial direction. The rod driving device has a vertical ball screw and upper and lower nut driving devices that respectively rotate and drive upper and lower nuts screwed to the ball screw, and the upper nut driving device is attached to the upper ends of the suspension rod and the telescopic device. The high-temperature heating device for a bar-shaped workpiece according to claim 4, wherein the lower nut driving device is connected to a lower end portion of the telescopic device. 6. The high-temperature heating device for a rod-shaped workpiece according to claim 3, wherein the rod driving device further includes a swing device that swings the suspension rod and the upper sealing device about a vertical axis.

Images