JP2512903Y2 - High temperature electric furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a high-temperature electric furnace using a carbon heater.

[Prior Art] In an electric furnace, an electrode rod or a heater terminal is supported on a furnace wall,
A heater is attached to one end of a heater terminal inside the furnace, and a cable for energization is supported at the other end of the heater terminal located outside the furnace.

The examples shown in FIGS. 1 and 2 of Japanese Utility Model Publication No. 60-25835 are
The flange of the attachment member is seated in the opening of the furnace wall, and the nut screwed to the electrode rod is locked to the flange to suspend the electrode rod in the opening of the furnace wall. The electric cable is connected to the upper end of the electrode rod, and the heater is fixed to the lower end of the electrode rod.

When using a metal heater, the maximum heater temperature is 1200 ° C.
Therefore, the electrode rod is also made of heat-resistant steel, and the temperature rise is suppressed by passing cooling water inside it. Further, since the weight of the current-carrying cable is received by the furnace wall via the nut screwed to the electrode bar and the mounting member of the furnace wall, the load on the electrode bar is lightened.

[Problems to be solved by the device]

When a metal heater is used, the above-mentioned actual Kosho 60-25835
Although the configuration disclosed in the publication is sufficient, when using a carbon heater and raising the furnace temperature to a high temperature of 1600 to 2500 ° C.,
The configuration of the conventional example described above is not preferable. For example, the difference in thermal expansion between the carbon heater and the metal electrode rod is large, resulting in poor support or damage to the carbon heater. In addition, the metal electrode rod cannot withstand the high temperature of 1600 to 2500 ° C., resulting in heat loss, which makes it unusable.

Therefore, it is proposed to use a carbon terminal instead of the metal electrode rod so as to withstand a high temperature of 1600 to 2500 ° C. However, at present, the proposal cannot be adopted because of the following points.

(1) The structure for supporting the carbon terminal on the furnace wall is insufficient.

(2) The inside of the high-temperature furnace at 1600 to 2500 ° C is kept in an inert gas atmosphere, but the seal between the carbon terminal and the furnace wall is insufficient, and there is a great risk of external oxygen entering the furnace.

Therefore, it is an object of the present invention to solve the above problems and provide a high temperature electric furnace using a carbon terminal.

[Means and Actions for Solving Problems]

In order to solve the above-mentioned problems, the present invention fixes a tubular body having a flange and a jacket to a furnace wall, fixes a flange of a terminal fitting to the flange via a heat-resistant sealing material, and a carbon terminal to the terminal fitting. Use a means to suspend the heater.

By adopting such a means, since the terminal fitting is supported on the furnace wall side, sufficient strength can be secured, and since the carbon terminal is hung from this terminal fitting, the carbon terminal needs only the strength to support its own weight. I wish I had it. Both the flanges of the tubular body and the terminal fitting are opposed to each other, and the heat-resistant sealing material is interposed therebetween, so that the sealing effect can be enhanced.

Specifically, the present invention comprises a metal cylinder having one end fixed to a furnace wall and a cooling water jacket, and a first flange fixed to the other end of the cylinder and closing the opening of the jacket. A metal terminal fitting having a cooling water passage inside and a second flange fixed to the outer wall surface facing the first flange via a heat-resistant sealing material, and a cylinder fixed to the lower portion of the terminal fitting. There is provided a high temperature electric furnace which has a carbon terminal located in the central through hole and a carbon heater supported on the lower surface of the carbon terminal and which is heated in an inert atmosphere.

〔Example〕

The furnace wall 2 of the high-temperature electric furnace 1 has a refractory heat insulating material 3 and a furnace wall 4 outside thereof. One end of the cylindrical body 6 is fixed to the opening 5 of the furnace wall 2. The metal cylinder 6 has a jacket 9 consisting of an outer pipe 7 and an inner pipe 8, and this jacket 9 is connected to a water supply pipe 10 and a drain pipe 11 so that cooling water can be supplied to the jacket 9. . The cylindrical body 6 has a first flange 12 on its upper portion, and this flange 12 closes the upper opening of the jacket 9.

The metal terminal fitting 13 has a second flange 14 welded to its lower end, and this flange 14 has a heat-resistant and electrically-insulating sealing material 15 such as Bakelite and O-rings 16 on both sides thereof. And faces the first flange 12. Both flanges 12 and 14 are fixed using an insulator 22, an electrically insulating collar 23, and bolts and nuts 17. The terminal fitting 13 has a cooling water passage 18 inside thereof, and is connected to an electric cable 19 for energization. Electric cables are thick and heavy due to the large current, but
The weight is received by the furnace wall 2 via the flanges 12 and 14.

The center of the lower portion of the terminal fitting 13 is projected, and a male screw is cut on the outer peripheral surface thereof. The female screw of the carbon terminal 20 is screwed into this male screw, and the carbon terminal 20 is hung on the terminal fitting 13. The carbon terminal 20 is arranged in the central passage of the cylindrical body 6 so as to receive the cooling atmosphere from the jacket 9, and the carbon heater 21 is screwed to the lower end thereof.

The current from the cable 19 is the terminal fitting 13, carbon terminal
20, to the carbon heater 21, and to the power source from the adjacent heater 21 via the carbon terminal 20. Both flanges 12, 14
Is electrically insulated, and the leakage of water to the cooling water passage 18 is prevented, which is safe.

Since the carbon heater has a high temperature of 1600 to 2500 ° C,
The inside of the furnace is an inert gas atmosphere, but since a face seal is secured between both flanges 12 and 14, oxygen does not enter the furnace from the outside.

Due to the cooling atmosphere from the cooling water passage 18 of the jacket 9 and the terminal fitting 13, the carbon terminal 20 and the terminal fitting 13 do not become hot.

〔effect〕

In the high temperature electric furnace according to the present invention, the carbon terminal is simply used as a member for holding the carbon heater and not as a structural member. That is, since the weight of the carbon terminal and the weight of the cable are supported by the furnace wall through the terminal fittings, there is no accidental damage to the carbon terminal.

Further, the consumption of the carbon terminal and the heater can be easily replaced, so that maintenance is easy.

[Brief description of drawings]

FIG. 1 is a partial sectional view of an electric furnace of one example of the present invention, and FIG. 2 is a plan view thereof. In the figure: 1 ... Electric furnace, 2 ... Furnace wall, 6 ... Cylindrical body, 9 ... Jacket, 12,14 ... Flange, 13 ... Terminal fitting, 15,1
6,17 …… Sealant, 20 …… Carbon terminal, 21 …… Carbon heater.

Claims (1)

(57) [Scope of utility model registration request] 1. A metal cylinder having one end fixed to a furnace wall and having a jacket for cooling water, a first flange fixed to the other end of the cylinder and closing an opening of the jacket, and cooling water inside. A metal terminal fitting having a passage and a second flange fixed to the outer wall surface of the metal fitting facing the first flange via a heat-resistant sealing material, and a central through hole of a tubular body fixed to the lower portion of the terminal fitting. A carbon terminal positioned inside, and a carbon heater supported on the lower surface of the carbon terminal,
A high-temperature electric furnace that heats in an inert atmosphere.