JP2000329475A - Heater furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heater furnace having a large length of soaking and being excellent in thermal efficiency and further in cooling efficiency. SOLUTION: This heater furnace comprises core tubes 1 and 2 holding an object of heating inside, heaters 7 and 8 enabling impression of heat on the core tubes 1 and 2 from the outer peripheries thereof, heat insulating materials 4 and 5 provided outside the heaters 1 and 8 and a cooling part 10 for cooling the heat insulating materials 4 and 5. In this case, the heater is divided into the sub-heater 7 and the main heater 8 and the sectional shape of the main heater 8 is made nonuniform.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heater furnace, and more particularly to a heater furnace for heating an object to be heated at the center of a cylindrical heater using a single power supply.

[0002]

FIG. 4 is a sectional view of a conventional heater furnace. This type heats an object to be heated at the center of a cylindrical heater using a single power supply. 31 is the first core tube, 32
Is a second core tube, 33 is an upper heat insulator, 34 is a side first heat insulator, 35 is a side second heat insulator, 36 is a lower heat insulator, 37 is a heater, and 38 is a cooling unit.

[0003] The heater 37 has a cylindrical shape, and a cylindrical second core tube 32 is inserted therein, and further, the first core tube 31 is inserted therein. A first side heat insulating material 34 is inserted into a side portion of the heater 37, and a second side heat insulating material 35 is inserted outside the first heat insulating material 34. An upper heat insulator 33 is provided above the heater 37, and a lower heat insulator 36 is provided below the heater 37. The periphery of the upper heat insulating material 33, the side second heat insulating material 35, and the lower heat insulating material 36 is covered with a cooling portion 38, and is configured so that the outside of the heater furnace can be cooled by flowing a refrigerant therein. .

The power supply of the heater 37 is a single power supply, and is not of a type in which a heater is divided to control current, voltage and power. The material of the heater 37 is carbon, and when a voltage is applied, heat is generated by internal electric resistance. The object to be heated is installed inside the first furnace tube 31 and a required amount of heat is applied thereto.

FIG. 5 is an explanatory diagram of the temperature distribution of the heater furnace of FIG. The horizontal axis shows the temperature (° C.), and the vertical axis shows the distance (mm) from the opening. The opening refers to the upper part of the first furnace tube 31. A maximum temperature of about 1150 ° C. is achieved near the center of the heater 37.

[0006]

The conventional heater furnace has the following problems.

(1) The temperature gradient is steep from the opening to the center of the heater 37 and the soaking length is short. The soaking length indicates a range that can be regarded as a substantially constant temperature, and the shorter the soaking length, the more difficult the heater furnace to use.

(2) At the time of heat retention / heating, heat is radiated more from the inside of the first furnace tube 31, and it takes a long time to reach the set temperature.

(3) Since the surface roughness of the heater 37 is substantially the same on the side of the second core tube 32 and the side of the first heat insulating material 34, heat radiation on the side of the first heat insulating material 34 is large and the heat efficiency is high. Is bad.

(4) In the case where the refrigerant flows through the cooling section 38, the cooling efficiency is poor because of the method of flowing through the entire cooling section 38.

Accordingly, an object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide a heater furnace having a long soaking length, a high heat efficiency and a high cooling efficiency.

[0012]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a furnace tube for placing an object to be heated therein, a heater capable of applying heat from the outer periphery of the furnace tube, and a heater arranged outside the heater. In a heater furnace including a heat insulator provided and a cooling unit for cooling the heat insulator, the heater is divided into a sub-heater and a main heater, and the cross-sectional shape of the main heater is made non-uniform.

The cross-sectional shape of the main heater is stepped so that the portion where the temperature is high is thick and the portion where the temperature is low is thin.

Further, the surface roughness of the main heater is made coarse on the furnace tube side and fine on the heat insulating material side.

The sub-heater was used as a heat insulating material without supplying an electric current at the time of keeping or raising the temperature.

The cooling section is composed of a pipe wound around the outer circumference of the heat insulating material and a refrigerant flowing through the pipe, and the refrigerant flows in order from a lower temperature to a higher temperature.

The furnace tube was filled with a heat insulating material at the time of heat retention / heating.

[0018]

FIG. 1 is a sectional view showing an embodiment of a heater furnace according to the present invention. 1 is a first core tube, 2 is a second core tube, 3 is an upper heat insulating material, 4 is a side first heat insulating material, 5 is a side second heat insulating material, 6 is a lower heat insulating material, 7 is a sub heater, and 8 is A main heater, 9 is an insulator, 10 is a cooling unit, and 11 is a center-filled heat insulating material. FIG. 2 is a detailed sectional view of the sub heater 7 and the main heater 8 of FIG.

The sub-heater 7 is inserted into the main heater 8 via an insulator 9. A cylindrical second furnace tube 2 is inserted therein, and a cylindrical first furnace tube 1 is further inserted therein. The first side heat insulating material 4 is inserted into a side portion of the main heater 8, and the second side heat insulating material 5 is inserted outside the first heat insulating material 4. The upper heat insulating material 3 is disposed above the sub-heater 7 and the main heater 8, and the lower heat insulating material 6 is disposed below the sub heater 7 and the main heater 8. The periphery of the upper heat insulating material 3, the side second heat insulating material 5, and the lower heat insulating material 6 is covered with a cooling unit 10, and the outside of the heater furnace can be cooled by flowing a coolant into the inside. .

The main heater 8 is characterized in that, according to the temperature distribution, the cross-sectional area is increased to increase the heat capacity at a high temperature, and the cross-sectional area is decreased at a low temperature to reduce the heat capacity. It is. This can be configured by forming the outer periphery of a cylindrical carbon into a step shape. The outer periphery, upper and lower portions of the main heater 8 are made finer in surface roughness, and the center side (inner side) is made rough so that heat is not radiated to the side first heat insulating material 4 side. With this configuration, the thermal efficiency can be improved.

The sub heater 7 has a cylindrical shape. And
The sub-heater 7 is used as a heat insulating material at the time of keeping and raising the temperature. That is, no current flows. However, when the heater furnace reaches the set temperature and heats the object to be heated, a current also flows through the sub-heater 7 to contribute to heating the object to be heated. Regardless of the outer and inner surface roughness, they have the same surface roughness.

The cooling unit 10 is configured such that a pipe is wound in a helical manner from above the second side heat insulating material 5 so that a refrigerant flows inside the pipe. The flow of the refrigerant was such that it flowed from a lower temperature part to a higher temperature part, that is, from the lower part to the upper part of the heater furnace and to the center part. By flowing the refrigerant in this manner, the outer periphery of the heater furnace could be efficiently cooled. In addition, at the time of keeping and raising the temperature of the heater furnace, it is possible to quickly reach the set temperature by filling the inside of the first furnace core tube 1 with the central-portion heat insulating material 11.

FIG. 3 is an explanatory diagram of the temperature distribution of the heater furnace of FIG. The horizontal axis is temperature (° C.), and the vertical axis is distance (mm) from the opening. The opening refers to the upper part of the first core tube 1.
A maximum temperature of about 1150 ° C. was achieved in the vicinity of the center of the main heater 8, and the range of 1000 ° C. or more (soaking length) could be increased from the conventional 330 mm to 380 mm.

The technology disclosed in the present invention is not limited to a vertical heater furnace, but can be applied to a horizontal or oblique heater furnace.

[0025]

According to the heater furnace of the present invention, the heater has a stepped cross-sectional shape and the outer surface has a fine surface roughness, so that a heater furnace having a long soaking length, good thermal efficiency, and further excellent cooling efficiency is provided. be able to.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a heater furnace according to the present invention.

FIG. 2 is a detailed sectional view of a sub heater and a main heater of FIG.

FIG. 3 is an explanatory diagram of a temperature distribution of the heater furnace of FIG. 1;

FIG. 4 is a sectional view of a conventional heater furnace.

FIG. 5 is an explanatory diagram of a temperature distribution of the heater furnace of FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 First furnace tube 2 Second furnace tube 3 Upper heat insulating material 4 Side first heat insulating material 5 Side second heat insulating material 6 Lower heat insulating material 7 Sub-heater 8 Main heater 9 Insulator 10 Cooling unit 11 Center filling heat insulating material 31 First furnace tube 32 Second furnace tube 33 Upper heat insulator 34 Side first heat insulator 35 Side second heat insulator 36 Lower heat insulator 37 Heater 38 Cooling unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // H05B 3/62 H05B 3/62

Claims (6)

[Claims] 1. A furnace tube into which an object to be heated is placed, a heater capable of applying heat from the outer periphery of the furnace tube, a heat insulating material provided outside the heater, and a cooling unit for cooling the heat insulating material. Wherein the heater is divided into a sub-heater and a main heater, and the main heater has a non-uniform cross-sectional shape. 2. The heater furnace according to claim 1, wherein the cross-sectional shape of the main heater is configured in a step-like manner so that a portion where the temperature is high is thick and a portion where the temperature is low is thin. 3. The heater furnace according to claim 1, wherein the surface roughness of the main heater is rough on the furnace tube side and fine on the heat insulating material side. 4. The heater furnace according to claim 1, wherein the sub-heater is configured to be used as a heat insulating material without flowing an electric current at the time of keeping or raising the temperature. 5. The cooling section comprises a pipe wound around the outer periphery of the heat insulating material and a refrigerant flowing through the pipe, and the refrigerant flows from a lower temperature to a higher temperature in order. The heater furnace according to claim 1, wherein the heater furnace comprises: 6. The heater furnace according to claim 1, wherein the furnace tube is configured to be filled with a heat insulating material at the time of keeping or raising the temperature.