JPH0152875B2 - - Google Patents
Info
- Publication number
- JPH0152875B2 JPH0152875B2 JP57021291A JP2129182A JPH0152875B2 JP H0152875 B2 JPH0152875 B2 JP H0152875B2 JP 57021291 A JP57021291 A JP 57021291A JP 2129182 A JP2129182 A JP 2129182A JP H0152875 B2 JPH0152875 B2 JP H0152875B2
- Authority
- JP
- Japan
- Prior art keywords
- heating element
- carbonaceous
- specific gravity
- heating
- carbon
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000010438 heat treatment Methods 0.000 claims description 87
- 239000003575 carbonaceous material Substances 0.000 claims description 22
- 230000005484 gravity Effects 0.000 claims description 18
- 230000017525 heat dissipation Effects 0.000 claims description 6
- 230000005855 radiation Effects 0.000 claims description 2
- 239000010410 layer Substances 0.000 description 17
- 239000002344 surface layer Substances 0.000 description 14
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 9
- 229910052799 carbon Inorganic materials 0.000 description 6
- 238000013021 overheating Methods 0.000 description 6
- 239000011810 insulating material Substances 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 229910002804 graphite Inorganic materials 0.000 description 3
- 239000010439 graphite Substances 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 229920000049 Carbon (fiber) Polymers 0.000 description 2
- 239000004917 carbon fiber Substances 0.000 description 2
- 229910010293 ceramic material Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000005611 electricity Effects 0.000 description 2
- 230000008020 evaporation Effects 0.000 description 2
- 238000001704 evaporation Methods 0.000 description 2
- 238000010304 firing Methods 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- CREMABGTGYGIQB-UHFFFAOYSA-N carbon carbon Chemical compound C.C CREMABGTGYGIQB-UHFFFAOYSA-N 0.000 description 1
- 239000011203 carbon fibre reinforced carbon Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 239000007770 graphite material Substances 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 239000012770 industrial material Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000011146 organic particle Substances 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
Landscapes
- Resistance Heating (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は高温加熱炉用炭素質発熱体に関する。[Detailed description of the invention] [Industrial application field] The present invention relates to a carbonaceous heating element for a high-temperature heating furnace.
従来、炭素材料、セラミツクス系材料、など各
種工業用材料の製造に用いられる高温加熱装置と
しては抵抗炉、誘導炉、アーク炉、プラズマ炉な
どの数多くの装置があるが、抵抗炉、特にタンマ
ン炉型式（以下、タンマン式という）の加熱炉は
比較的単純な加熱手段によるため広く用いられて
いる。
Conventionally, there are many types of high-temperature heating equipment used in the production of various industrial materials such as carbon materials and ceramic materials, such as resistance furnaces, induction furnaces, arc furnaces, and plasma furnaces. The heating furnace of this type (hereinafter referred to as the Tammann type) is widely used because it uses a relatively simple heating means.
タンマン式加熱炉を用い2000〜3000℃付近の高
温加熱を行なうには、管状又は筒状の抵抗発熱体
（以下、単に発熱体という）に電流を通じ、ジユ
ール熱によりこれを加熱して被処理物を管内に静
置または連続的に通過させ焼成するが、通常は窒
素やアルゴン等の不活性ガス中あるいは減圧（真
空）中で行なわれ、発熱体としては一般に炭素
（黒鉛）材が用いられる。 To perform high-temperature heating in the vicinity of 2000 to 3000°C using a Tammann heating furnace, current is passed through a tubular or cylindrical resistance heating element (hereinafter simply referred to as the heating element), which is heated by Joule heat to heat the workpiece. is allowed to stand still or continuously passed through a tube and fired, but this is usually done in an inert gas such as nitrogen or argon or under reduced pressure (vacuum), and a carbon (graphite) material is generally used as the heating element.
〔発明が解決しようとする課題〕
上記の炭素材からなる発熱体は、金属材料やセ
ラミツクス系材料の発熱体では実用に供し得ない
2000℃〜3000℃の高温領域においても、溶融、分
解などを起さず発熱体として充分その機能を発揮
し、かつ比較的安価な材料であるが、前述の高温
下で長時間使用すると徐々に減耗し継続使用が困
難になる。[Problem to be solved by the invention] The heating element made of the above-mentioned carbon material cannot be put into practical use with a heating element made of metal or ceramic materials.
Even in the high temperature range of 2000°C to 3000°C, it does not melt or decompose and performs its function as a heating element, and it is a relatively inexpensive material. It wears out and becomes difficult to continue using.
このような炭素質発熱体の高温下での減耗には
多くの要因が関与するが、基本的な要因の一つと
して高温度における炭素質発熱体表面からの炭素
の蒸発を挙げることができる。すなわち、炭素も
そのものの蒸気圧は2000〓（1727℃）で3.34×
10-11気圧、2500〓（2227℃）で1.79×10-7気圧、
3000〓（2727℃）で5.43×10-5気圧の値を示し、
また2500〓（2227℃）では1.16×10-2ｇ／cm2・hr
の炭素が蒸発すると言われている。従つて、2000
℃以上の高温度に長時間保たれる高温加熱炉内の
発熱体として炭素質発熱体を使用するときは、炭
素の蒸発に伴う炭素質発熱体の減耗は避けられ
ず、特に連続処理用高温加熱炉の発熱体としては
大きな問題である。 Many factors are involved in such depletion of the carbonaceous heating element at high temperatures, and one of the fundamental factors is the evaporation of carbon from the surface of the carbonaceous heating element at high temperatures. In other words, the vapor pressure of carbon itself is 3.34× at 2000〓 (1727℃)
10 -11 atm, 1.79×10 -7 atm at 2500〓 (2227℃),
It shows a value of 5.43×10 -5 atm at 3000〓 (2727℃),
Also, at 2500〓 (2227℃), it is 1.16×10 -2 g/cm 2・hr
of carbon is said to evaporate. Therefore, 2000
When using a carbonaceous heating element as a heating element in a high-temperature heating furnace that is kept at a high temperature of ℃ or higher for a long time, wear and tear of the carbonaceous heating element due to carbon evaporation is unavoidable, especially in high-temperature heating for continuous processing. This is a big problem as a heating element for a heating furnace.
さらに上記高温加熱炉用炭素質発熱体において
は、発熱体に温度ムラが発生すると、低温部に比
べて高温部の減耗が甚だしくなり、ついにはこの
高温部が発熱体の破損点となる。従つて、このよ
うな異常な高温部、即ち過熱点が生じないよう
に、炭素質発熱体に温度分布の発生を防ぐことが
重要である。 Furthermore, in the above-mentioned carbonaceous heating element for a high-temperature heating furnace, when temperature unevenness occurs in the heating element, the high-temperature part wears out more than the low-temperature part, and this high-temperature part eventually becomes the point of failure of the heating element. Therefore, it is important to prevent the occurrence of temperature distribution in the carbonaceous heating element so that such abnormally high temperature areas, ie, overheating points, do not occur.
本発明者らは、上記炭素質発熱体の問題点、即
ち高温下での減耗を防止し、かつ温度分布が均一
で過熱点の発生し難い炭素質発熱体について鋭意
検討を行ない、先に該発熱体として炭素質発熱体
に炭素繊維を巻回した発熱体を用いた高温加熱炉
を提案したが、さらに検討を進めた結果、本発明
に至つたのである。 The inventors of the present invention have conducted extensive studies on carbonaceous heating elements that prevent the above-mentioned problems with the carbonaceous heating element, that is, they prevent wear and tear under high temperatures, have a uniform temperature distribution, and are less likely to generate overheating points, and have previously addressed the above-mentioned problems. We proposed a high-temperature heating furnace using a carbon fiber heating element as a heating element, but as a result of further study, we arrived at the present invention.
すなわち、本発明の課題は炭素質発熱体の高温
下での減耗をできる限り防止し、かつ温度分布が
均一で過熱点の発生し難い炭素質発熱体を提供す
ることにある。 That is, an object of the present invention is to provide a carbonaceous heating element that prevents wear and tear of the carbonaceous heating element as much as possible under high temperatures, has a uniform temperature distribution, and is less likely to generate overheating spots.
本発明の上記課題は、見掛け比重の差が0.1以
上の２種以上の炭素材からなる積層体であり、か
つ放熱面を構成する炭素材の見掛け比重が放熱面
の内層部を構成する炭素材より小である高温加熱
炉用炭素質発熱体によつて解決できる。
The above-mentioned object of the present invention is to provide a laminate made of two or more types of carbon materials with a difference in apparent specific gravity of 0.1 or more, and where the apparent specific gravity of the carbon material constituting the heat dissipation surface is the same as that of the carbon material constituting the inner layer of the heat dissipation surface. This problem can be solved by using a smaller carbonaceous heating element for high-temperature heating furnaces.
すなわち、本発明の炭素質発熱体は見掛け比重
を異にする２種以上の炭素材を一体的に積層させ
たもので、該発熱体の放熱面となる表層部の炭素
材は内層部の炭素材より見掛け比重が小さいもの
を用いる必要がある。発熱体の表層部の見掛け比
重を内層部より小さくしておくと、表層部が一種
の断熱層となつて、発熱体の温度分布を均一化さ
せるように働く。 That is, the carbonaceous heating element of the present invention is one in which two or more types of carbon materials having different apparent specific gravity are integrally laminated, and the carbon material in the surface layer that becomes the heat dissipation surface of the heating element is higher than the carbon material in the inner layer. It is necessary to use a material whose apparent specific gravity is smaller than the material. When the apparent specific gravity of the surface layer of the heating element is made smaller than that of the inner layer, the surface layer acts as a kind of heat insulating layer and works to equalize the temperature distribution of the heating element.
この発熱体の表層部の炭素材の見掛け比重は、
好ましくは1.4以下、より好ましくは0.7〜1.4であ
り、発熱体としての形状が保持できる範囲内でな
るべく小さい方が望ましい。一方、この見掛け比
重を1.4より大きくすることは、発熱体の主たる
発熱部分である内層部の炭素材（通常は、比重
1.5以上の高密度黒鉛材）との比重差が実質的に
とれず、本発明の目的が達成し難くなる。 The apparent specific gravity of the carbon material in the surface layer of this heating element is
It is preferably 1.4 or less, more preferably 0.7 to 1.4, and preferably as small as possible within the range that allows the shape of the heating element to be maintained. On the other hand, increasing the apparent specific gravity to greater than 1.4 means that the carbon material (usually
1.5 or higher) and the specific gravity difference between the two materials (high-density graphite material of 1.5 or more) cannot be substantially maintained, making it difficult to achieve the object of the present invention.
このように発熱体の表層部に内層部より見掛け
比重が小さい炭素材を用いると、該表層部の電気
抵抗が内層部に比して大きく、かつ熱伝導率は小
さくなる。従つて、このような構成の発熱体に直
接電気を通じると、表層部の炭素材はその内層部
の炭素材に比べ電気抵抗が大きいから、電気が流
れ難くなる。従つて、発熱体の表層部は発熱量が
少なく、しかも熱伝導率が小さくなるから内層部
の炭素材に対しては一種の断熱層として働くた
め、前述した過熱点の形成防止と共に、発熱体全
体としての温度分布ムラを減少させることができ
る。 When a carbon material having a smaller apparent specific gravity than the inner layer is used in the surface layer of the heating element in this manner, the electrical resistance of the surface layer is larger than that of the inner layer, and the thermal conductivity is lower. Therefore, when electricity is directly applied to a heating element having such a structure, it becomes difficult for electricity to flow through the carbon material in the surface layer because the electrical resistance is higher than that in the inner layer. Therefore, since the surface layer of the heating element generates less heat and has a lower thermal conductivity, it acts as a kind of heat insulating layer for the carbon material in the inner layer. Overall temperature distribution unevenness can be reduced.
本発明の発熱体を構成する炭素材としては、公
知の炭素もしくは黒鉛粒子に各種のバインダーを
配合し、所望の形状に成形した後、約2000℃以上
の不活性雰囲気中で加熱することにより得られる
が、炭素材に見掛け比重の差を与えるために、特
に表層部の見掛け比重の小さい炭素材料にはフイ
ラーコークスや黒鉛粒子の粒径を選定し充填間隔
を制御して成形するか、もしくは炭素化率の低い
有機質粒子を適当に混合して成形したものを焼成
する等の方法が好ましく採用できる。また炭素繊
維の布帛、フエルト状などの繊維構造物に適当な
樹脂含浸を行ない焼成して得られる、いわゆる炭
素−炭素複合材を用いることもできるが、いずれ
の場合も発熱体の表層部（放熱面）は見掛け比重
が好ましくは1.4以下、より好ましくは1.0以下と
なるように空隙部を形成させるのが望ましい。 The carbon material constituting the heating element of the present invention can be obtained by blending various binders with known carbon or graphite particles, molding it into a desired shape, and then heating it in an inert atmosphere at about 2000°C or higher. However, in order to give the carbon material a difference in apparent specific gravity, it is necessary to select the particle size of filler coke or graphite particles and control the filling interval to mold the carbon material, which has a small apparent specific gravity, especially in the surface layer. A method such as appropriately mixing organic particles with a low conversion rate, molding the product, and firing the product can be preferably employed. In addition, a so-called carbon-carbon composite material obtained by impregnating a fiber structure such as carbon fiber cloth or felt with an appropriate resin and firing it can also be used, but in either case, the surface layer of the heating element (heat dissipation It is desirable that voids be formed in the surface) so that the apparent specific gravity is preferably 1.4 or less, more preferably 1.0 or less.
次に、本発明の実施例としてタンマン式の加熱
炉について説明する。 Next, a Tammann type heating furnace will be described as an example of the present invention.
すなわち、第１図および第２図は従来一般に用
いられているタンマン式加熱炉の側断面図、第３
図は本発明になる炭素質発熱体の一例を示す斜視
図、第４図は該炭素質発熱体を装着した加熱炉の
一例を示す断面図である。 In other words, Figures 1 and 2 are side sectional views of the Tammann type heating furnace commonly used in the past;
FIG. 4 is a perspective view showing an example of a carbonaceous heating element according to the present invention, and FIG. 4 is a sectional view showing an example of a heating furnace equipped with the carbonaceous heating element.
図において、１は従来の炭素質発熱体、２は断
熱材、３は電極、４は出入口部シール部、５は外
殻、６は発熱体の保護管、Ａは本発明の炭素質発
熱体、ａはＡの表層部、ｂはＡの内層部を示す。 In the figure, 1 is a conventional carbonaceous heating element, 2 is a heat insulator, 3 is an electrode, 4 is an entrance/exit seal, 5 is an outer shell, 6 is a protection tube for the heating element, and A is a carbonaceous heating element of the present invention. , a indicates the surface layer of A, and b indicates the inner layer of A.
第４図に示すように、本発明の炭素質発熱体Ａ
は内層部ｂに見掛け比重の高い炭素材、表層部ａ
に見掛け比重の低い炭素材を一体的に積層させた
構造になつており、その周りを従来の断熱材２で
覆つている。 As shown in FIG. 4, the carbonaceous heating element A of the present invention
is a carbon material with high apparent specific gravity in the inner layer b, and a surface layer a
It has a structure in which a carbon material with a low apparent specific gravity is integrally laminated on the inside, and the surrounding area is covered with a conventional heat insulating material 2.
すなわち、従来の炉型式では発熱体１の周りに
断熱材層２がランダムに充填されている。このた
め、断熱材２の充填方法によつては発熱体１の表
面に極めて不均一な断熱層が形成されることにな
る。このような不均一な断熱層は発熱体１の表面
に過熱点を形成させる最大の要因となる。例え
ば、第１図において、発熱体１下部に充填される
断熱材２の充填密度は発熱体１上部のそれよりも
小さくなることが容易に想像できる。事実、第１
図に示すような従来の加熱炉では発熱体１下部の
減耗が最も著しいことからも確めることができ
る。また第２図のような炉型式では、発熱体１と
保護管６との間の空気層が有効に働いてある程度
過熱点が減少し発熱体１下部の減耗が減少する
が、尚十分ではない。 That is, in the conventional furnace type, the heat insulating material layer 2 is randomly filled around the heating element 1. Therefore, depending on the filling method of the heat insulating material 2, an extremely non-uniform heat insulating layer will be formed on the surface of the heating element 1. Such a non-uniform heat insulating layer is the biggest factor in forming overheating spots on the surface of the heating element 1. For example, in FIG. 1, it can be easily imagined that the packing density of the heat insulating material 2 filled in the lower part of the heating element 1 is smaller than that in the upper part of the heating element 1. Fact, first
This can be confirmed from the fact that in the conventional heating furnace as shown in the figure, the lower part of the heating element 1 is most severely worn out. In addition, in the furnace type shown in Fig. 2, the air layer between the heating element 1 and the protective tube 6 works effectively, reducing the overheating point to some extent and reducing wear and tear on the lower part of the heating element 1, but it is still not sufficient. .
これに対し本発明の炭素質発熱体Ａは、内層部
ｂの表面に、見掛け比重の小さい表層部ａが被覆
した状態になつているため、より均一な温度分布
を示すようになり、所定温度以上の高温度加熱
点、即ち過熱点の形成が抑制され、従つて、発熱
体の減耗を抑えることができる。 On the other hand, in the carbonaceous heating element A of the present invention, since the surface of the inner layer b is covered with the surface layer a having a small apparent specific gravity, a more uniform temperature distribution is exhibited, and a predetermined temperature The formation of the above-mentioned high-temperature heating points, that is, overheating points, is suppressed, and therefore the wear and tear of the heating element can be suppressed.
本発明によれば、
ａ 発熱体の減耗に基づく加熱温度ムラが減少
し、製品品質が著しく安定化する。
According to the present invention, a. Heating temperature unevenness due to wear and tear of the heating element is reduced, and product quality is significantly stabilized.
ｂ 発熱体の寿命が大幅に延長する。b. The life of the heating element is significantly extended.
ｃ 発熱体の寿命延長のため、交換周期が延長で
き、発熱体費の節減や製品コスト低減が図れ
る。c. Because the lifespan of the heating element is extended, the replacement cycle can be extended, reducing heating element costs and product costs.
などの効果を奏する。It has the following effects.
第１図および第２図は従来一般に用いられてい
るタンマン式加熱炉の側断面図、第３図は本発明
になる炭素質発熱体の一例を示す斜視図、第４図
は該炭素質発熱体を装着した加熱炉の一例を示す
断面図である。
１；発熱体（炭素質）、２；断熱材、３；電極、
４；出入口部シール部、５；外殻、６；発熱体の
保護管、Ａ；本発明の炭素質発熱体、ａ；Ａの表
層部（放熱面）、ｂ；Ａの内層部。
Figures 1 and 2 are side sectional views of a conventionally commonly used Tammann heating furnace, Figure 3 is a perspective view showing an example of the carbonaceous heating element of the present invention, and Figure 4 is the carbonaceous heating element. FIG. 2 is a sectional view showing an example of a heating furnace equipped with a heating furnace. 1; heating element (carbonaceous), 2; heat insulating material, 3; electrode,
4; entrance/exit seal portion; 5; outer shell; 6; protective tube of heating element; A; carbonaceous heating element of the present invention; a; surface layer portion (heat radiation surface) of A; b; inner layer portion of A.
Claims (1)
材からなる積層体であり、かつ放熱面を構成する
炭素材の見掛け比重が放熱面の内層部を構成する
炭素材より小である高温加熱炉用炭素質発熱体。 ２ 特許請求の範囲１において、発熱体の放熱面
を構成する炭素材の見掛け比重が1.4以下である
高温加熱炉用炭素質発熱体。[Scope of Claims] 1. A laminate consisting of two or more types of carbon materials with a difference in apparent specific gravity of 0.1 or more, and where the apparent specific gravity of the carbon material constituting the heat dissipation surface is the carbon material constituting the inner layer of the heat dissipation surface. A smaller carbonaceous heating element for high-temperature heating furnaces. 2. The carbonaceous heating element for a high-temperature heating furnace according to claim 1, wherein the carbon material constituting the heat radiation surface of the heating element has an apparent specific gravity of 1.4 or less.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2129182A JPS58140987A (en) | 1982-02-15 | 1982-02-15 | Composite carbon heater |
| DE8282306719T DE3277106D1 (en) | 1981-12-18 | 1982-12-16 | Improved electric resistance heating element and electric resistance heating furnace using the same as heat source |
| EP82306719A EP0082678B1 (en) | 1981-12-18 | 1982-12-16 | Improved electric resistance heating element and electric resistance heating furnace using the same as heat source |
| US06/451,391 US4490828A (en) | 1981-12-18 | 1982-12-20 | Electric resistance heating element and electric resistance heating furnace using the same as heat source |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2129182A JPS58140987A (en) | 1982-02-15 | 1982-02-15 | Composite carbon heater |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58140987A JPS58140987A (en) | 1983-08-20 |
| JPH0152875B2 true JPH0152875B2 (en) | 1989-11-10 |
Family
ID=12051028
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2129182A Granted JPS58140987A (en) | 1981-12-18 | 1982-02-15 | Composite carbon heater |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58140987A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0425997A (en) * | 1990-05-22 | 1992-01-29 | Toshiba Electric Appliance Co Ltd | Automatic vending machine |
| JP4528495B2 (en) * | 2003-05-26 | 2010-08-18 | 住友電気工業株式会社 | Baking method of heat insulation pipe for superconducting cable |
-
1982
- 1982-02-15 JP JP2129182A patent/JPS58140987A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58140987A (en) | 1983-08-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0082678B1 (en) | Improved electric resistance heating element and electric resistance heating furnace using the same as heat source | |
| US3146340A (en) | Heating devices | |
| US2215587A (en) | Rodlike heating element | |
| IT9020673A1 (en) | METHOD FOR FORMING SINTERED PRODUCTS | |
| US3120453A (en) | Porous carbonaceous body with sealed surface for use as arc-furnace electrode or structural component of nuclear reactors | |
| US3497674A (en) | Process and apparatus for direct electrical heating of gaseous substances | |
| US3345448A (en) | High temperature electrical connection | |
| US2745932A (en) | Electric resistor | |
| JPH0152875B2 (en) | ||
| JPS6410938B2 (en) | ||
| US3984088A (en) | Vaporizing crucible for vacuum vapor coating systems | |
| US1088296A (en) | Electrode. | |
| US3400206A (en) | Consumable electrode stabilized against warping, formed from compacted refractory metal particles | |
| JP3287029B2 (en) | heating furnace | |
| US4853941A (en) | D.C. arc furnace having electrically conductive hearth and method for making same | |
| JP3341780B2 (en) | Crucible for vacuum deposition equipment | |
| US3970768A (en) | Grid electrodes | |
| US2140228A (en) | Electrically heated furnace | |
| US984119A (en) | Electric furnace. | |
| JPS58106384A (en) | Heating furnace | |
| US1088734A (en) | Carbon electrode having protective covering, and process for producing same. | |
| US1545951A (en) | Apparatus and process for fusing materials | |
| US3671656A (en) | Electrode contact device | |
| JP2585352B2 (en) | Melting tank | |
| JPH0251234B2 (en) |