US2009732A - Electric resistor - Google Patents
Electric resistor Download PDFInfo
- Publication number
- US2009732A US2009732A US618844A US61884432A US2009732A US 2009732 A US2009732 A US 2009732A US 618844 A US618844 A US 618844A US 61884432 A US61884432 A US 61884432A US 2009732 A US2009732 A US 2009732A
- Authority
- US
- United States
- Prior art keywords
- resistor
- refractory
- rod
- container
- packing
- 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 - Lifetime
Links
- 210000004907 gland Anatomy 0.000 description 13
- 238000012856 packing Methods 0.000 description 11
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 9
- 238000010276 construction Methods 0.000 description 8
- 229910010271 silicon carbide Inorganic materials 0.000 description 8
- 238000010438 heat treatment Methods 0.000 description 7
- 239000011819 refractory material Substances 0.000 description 7
- 239000000203 mixture Substances 0.000 description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 5
- 239000004568 cement Substances 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 239000000571 coke Substances 0.000 description 4
- 239000003575 carbonaceous material Substances 0.000 description 3
- 239000004020 conductor Substances 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 229910002804 graphite Inorganic materials 0.000 description 3
- 239000010439 graphite Substances 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 229910052573 porcelain Inorganic materials 0.000 description 3
- 239000004576 sand Substances 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 230000009972 noncorrosive effect Effects 0.000 description 2
- 229910000792 Monel Inorganic materials 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 229910021538 borax Inorganic materials 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 229920000136 polysorbate Polymers 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 229910052851 sillimanite Inorganic materials 0.000 description 1
- 239000004328 sodium tetraborate Substances 0.000 description 1
- 235000010339 sodium tetraborate Nutrition 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B3/00—Ohmic-resistance heating
- H05B3/20—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater
- H05B3/22—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater non-flexible
- H05B3/28—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater non-flexible heating conductor embedded in insulating material
- H05B3/283—Heating elements having extended surface area substantially in a two-dimensional plane, e.g. plate-heater non-flexible heating conductor embedded in insulating material the insulating material being an inorganic material, e.g. ceramic
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B2203/00—Aspects relating to Ohmic resistive heating covered by group H05B3/00
- H05B2203/002—Heaters using a particular layout for the resistive material or resistive elements
- H05B2203/003—Heaters using a particular layout for the resistive material or resistive elements using serpentine layout
Definitions
- Fig. l is a side elevation, partly broken away, of an -electrical resistor embodying the invention
- Fig. 2 is a transverse vertical section taken on the line 2-2 in Fig. l, and
- Fig. 3 is an enlarged sectional view of amodified form of terminal.
- the unit heating or resistor element designated as a whole by the unit I comprises a rectangular box or container II open at its top or one side.
- the box-like sheath or container may be made of any suitable refractory material that is a good conductor of heat, such as recrystallized silicon carbide or bonded silicon carbide.
- the container provides a housing for a resistor element proper I2,
- the packing I3 covers the resistor and fills the container up to within a short distance ofA its top, the remainder of the space above the packing being filled with a cementitious compound indicated at I4, which is made of any suitable refractory material which hardens when heated, such as silicon carbide and a binder.
- This cement covering I4 serves not only to provide a gas-tight covering for the open top of the container but also acts to support the conducting terminals, the ends of which are embedded in it so that when the cement hardens the terminals are held rigidly in place.
- the terminals are of a novel construction, each comprising a graphite or carbon rod I6 enclosed in a sheath, jacket or tube I1 of porcelain, sillimanite or other refractory material, and air-tight up to at least 3000 F.
- the tube extends downward through the cement I4 and into the packing I3, being supported and held rigidly in place by the cement.
- the space between the rod and the tube is packed with an embedding material indicated at I8 which preferably is a refractory and carbonaceous mixture such as silicon carbide nes and powdered coke or graphite.
- the tube I'I is cemented as indicated at I9 into a counter-sink 20 in a metallic gland 2
- This gland is made of a metal that is non- 'corrosive and a good conductor of electricity, such as Monel metal or nickel, so that a good electrical connection can be made with it by means of a plate or link 22 which is clamped against its top by a nut 23, said nut being screwed onto the upper reduced threaded end portion 2Ia of the gland or cap 2
- the upper end of the terminal rod I6 is seated in a depression in the end of the gland 2
- the lower end portion of the rod is preferably reduced in diameter asl indicated at I6a and suitably contacts with the resistor I2.
- the steep temperature gradient, or critical point, is confined to the point where the labrupt change in cross section of the rod occurs, namely at the shoulder between the small and large portions.
- the upper or large portion of the rod is covered by its refractory sheath which extends outward to the cooler point and inward or oppositely to the hotter point of smaller crosssection.
- the tube or sleeve I'I makes an air-tight joint with the metallic gland 2
- the heating unit I is made in as small dimensions as may be without sacrificing mechanical strength, and as will be seen is of a suitable shape to enable it to be slipped into a seat or bed 2S in the wall 25 of the furnace. Although particularly adapted for ready replacement, it may of course if found desirable, be built into the furnace.
- the metallic gland has a high melting point, does not corrode at high temperatures, and is not affected by carbon at high temperatures, so that no oxide is formed nor is thev composition of the metal changed, with the result that even at a very high temperature a good electrical connection is maintained.
- the porcelain tubes are very refractory and are air-tight up to 3000o F. or more, and are connected to the glands by a refractory joint.
- the terminal rods are themselves infusible and packed with a high refractory powder. As a result of the arrangement and construction, the entire unit will withstand extremely high temperatures.
- Fig. 3 a modified form of terminal wherein the graphite rod 2B (corresponding to the rod I6 of the Figs. 1-2 construction) is made of two parts 2l and 28, the part 28 of small diameter threading into a tapped seat in the bottom of the larger part 2'I.
- This larger part at its upper end projects through an opening in the top of the gland 29 and is threaded as indicated at 30 to receive a block 3
- the threaded portion 3D of the rod extends downward through the opening in the gland 29 which is screwed on it.
- An electrical resistor provided with a terminal comprising a carbonaceous rod, a refractory tube of porcelain enclosing the rod and airtight ⁇ up to at least 3000 F., a' non-corrosive metallic gland of metal of high melting point into which one end of the tube is cemented to make a gas-tight joint, a refractory packing of silicon carbide nes or the like between the rod and the tube, and means providing a gas-tight joint be'- tween said resistor and the other end of the tube.
- a heating element comprising azig-zag resistor member of carbonaceous material, an open top receptacle of silicon carbide or like refractory material in which said member is housed, a packu ing between said receptacle and said member in which said member is embedded, said packing comprising a mixture of fire sand, powdered coke and a fusible material, a cementitious covering providing a gas-tight seal over the open top of the receptacle, and conducting terminals embedded at their ends in said packing material and projecting outward from said resistor member, said terminals comprising tubular sheaths, and means providing gas-tight seals at the outer ends of said tubular sheaths.
- a heating element comprising a zig-zag resistor member of carbonaceous material, an opentop receptacle of silicon carbide or like refractory material in which said member is housed, a packing between said receptacle and said member in which said member is* embedded, said packingA comprising a mixture of fire sand, powdered coke and a fusible material, a cementitious covering providing a gas-tight seal over the open top of the receptacle, and conducting terminals comprising carbonaceous rods and enclosing refractory tubes, the ends of said tubes being embedded in said packing.
- a heating element comprising a carbonaceous resistance member, a container therefor of refractory material, said container having an open top, conducting terminals comprising carbonaceous rods, refractory tubes enclosing said rods, metallic glands into which the outer ends of said tubes are cemented, and a refractory packing completely covering said resistance member, and a cementitious covering providing a top for said container, 'the end portions of said tubes being embedded in said covering.
- a heating element comprising a carbonaceous resistance member, a container therefor of refractory material, said container having an open top, conducting terminals comprising carbonaceous rods, refractory tubes enclosing said rods, metallic glands into which the outer ends of said tubes are cemented, and a refractory packing completely covering said resistance member and a refractory cover providing a top for said container, the end portions of said tubes being cemented in said cover.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Inorganic Chemistry (AREA)
- Furnace Details (AREA)
Description
July 30, 1935. R. L. HARPER ET-AL 2,009,732
' ELECTRIC RESISTOR Filed June 25, 1952 Patented July 30, 1935 UNITED STATES PATENTv OFFICE ELECTRIC RESISTOR Furnace Corporation,
ration of New York Buffalo, N. Y., a corpo- Application June 2.3, 1932, Serial No. 618,844
5 Claims.
5 invention has for its object the production of Cal an improved resistor preferably of the zig-zag type and having conducting terminals of novel construction, made in the form of a self-contained unit of comparatively small size which may be readily introduced into a seat or slot in an electrical furnace and removed therefrom without dismantling or otherwise disturbing the furnace structure.
It has been usual heretofore to emplace resistors of this general type in a chamber built into the electrical furnace with the resulting disadvantage that when replacements were required the furnace had to be partially dismantled or torn down in order to remove the resistor, necessitating shut-downs in the plant while replacements were being made. Furthermore, it has been diflcult in prior constructions adequately to protect the terminals against oxidation generally and particularly at their outer ends. Our present invention overcomes these defects by providing a unit resistor readily replaceable and having suitably protected air-cooled terminals, doing away with the need of water-cooling.
To the above and other ends which will subsequently appear our invention consists in the features and methods of construction, combinations of devices and arrangements of parts hereinafter described and particularly pointed out in the appended claims.
The preferred form of the invention is shown in the accompanying drawing wherein Fig. l is a side elevation, partly broken away, of an -electrical resistor embodying the invention;
Fig. 2 is a transverse vertical section taken on the line 2-2 in Fig. l, and
Fig. 3 is an enlarged sectional view of amodified form of terminal.
As shown in the drawing, the unit heating or resistor element designated as a whole by the unit I comprises a rectangular box or container II open at its top or one side. The box-like sheath or container may be made of any suitable refractory material that is a good conductor of heat, such as recrystallized silicon carbide or bonded silicon carbide. The container provides a housing for a resistor element proper I2,
I3 to be introduced into the container completely covering the resistor I2 on all sides. ing preferably is a mixture of fire sand or granular silicon carbide, powdered coke and a comparatively small quantity of borax or other fusible material. The packing I3 covers the resistor and fills the container up to within a short distance ofA its top, the remainder of the space above the packing being filled with a cementitious compound indicated at I4, which is made of any suitable refractory material which hardens when heated, such as silicon carbide and a binder. This cement covering I4 serves not only to provide a gas-tight covering for the open top of the container but also acts to support the conducting terminals, the ends of which are embedded in it so that when the cement hardens the terminals are held rigidly in place.
The terminals, indicated generally at I5, are of a novel construction, each comprising a graphite or carbon rod I6 enclosed in a sheath, jacket or tube I1 of porcelain, sillimanite or other refractory material, and air-tight up to at least 3000 F. The tube extends downward through the cement I4 and into the packing I3, being supported and held rigidly in place by the cement. The space between the rod and the tube is packed with an embedding material indicated at I8 which preferably is a refractory and carbonaceous mixture such as silicon carbide nes and powdered coke or graphite. This mixture minimizes the circulation of gases and insures a reducing atmosphere, the silicon carbide powder being a good conductor of heat, and is effective in cooling the larger end portion of the rod I6. At the top the tube I'I is cemented as indicated at I9 into a counter-sink 20 in a metallic gland 2|. This gland is made of a metal that is non- 'corrosive and a good conductor of electricity, such as Monel metal or nickel, so that a good electrical connection can be made with it by means of a plate or link 22 which is clamped against its top by a nut 23, said nut being screwed onto the upper reduced threaded end portion 2Ia of the gland or cap 2|.
The upper end of the terminal rod I6 is seated in a depression in the end of the gland 2|. The lower end portion of the rod is preferably reduced in diameter asl indicated at I6a and suitably contacts with the resistor I2. As a result of this construction, with the same current iiowing in the circuit more heat will be generated -in the portion I6a than in the resistor I2, making it impossible for heat to be conducted away from the resistor through the larger upper portion of This packthe rod I6. This larger portion is of such cross section that little heat is generated in it due to the passage of the electric current, so that it,
emerges from the furnace at a comparatively low temperature. The steep temperature gradient, or critical point, is confined to the point where the labrupt change in cross section of the rod occurs, namely at the shoulder between the small and large portions. The upper or large portion of the rod is covered by its refractory sheath which extends outward to the cooler point and inward or oppositely to the hotter point of smaller crosssection. At its outer end the tube or sleeve I'I makes an air-tight joint with the metallic gland 2|, due to the cement I9, and at its inner or hot end the sleeve extends into the packing I3. Due to this construction the necessity for water-cooling of the terminals is avoided, the metallic glands being non-corrosive and having a high melting point, and the large diameter of the terminal rods causing them to generate a comparatively small amount of heat.
The heating unit I is made in as small dimensions as may be without sacrificing mechanical strength, and as will be seen is of a suitable shape to enable it to be slipped into a seat or bed 2S in the wall 25 of the furnace. Although particularly adapted for ready replacement, it may of course if found desirable, be built into the furnace.
It will be noted that all of theparts comprise in our improved heating element or resistor device will withstand high temperatures. The metallic gland has a high melting point, does not corrode at high temperatures, and is not affected by carbon at high temperatures, so that no oxide is formed nor is thev composition of the metal changed, with the result that even at a very high temperature a good electrical connection is maintained. The porcelain tubes are very refractory and are air-tight up to 3000o F. or more, and are connected to the glands by a refractory joint. The terminal rods are themselves infusible and packed with a high refractory powder. As a result of the arrangement and construction, the entire unit will withstand extremely high temperatures.
Changes may. be made without departing from the invention, and as an example we have illustrated in Fig. 3 a modified form of terminal wherein the graphite rod 2B (corresponding to the rod I6 of the Figs. 1-2 construction) is made of two parts 2l and 28, the part 28 of small diameter threading into a tapped seat in the bottom of the larger part 2'I. This larger part at its upper end projects through an opening in the top of the gland 29 and is threaded as indicated at 30 to receive a block 3| of carbonaceous material with which electrical connection is directly made. The threaded portion 3D of the rod extends downward through the opening in the gland 29 which is screwed on it.
I We claim: Y
1. An electrical resistor provided with a terminal comprising a carbonaceous rod, a refractory tube of porcelain enclosing the rod and airtight` up to at least 3000 F., a' non-corrosive metallic gland of metal of high melting point into which one end of the tube is cemented to make a gas-tight joint, a refractory packing of silicon carbide nes or the like between the rod and the tube, and means providing a gas-tight joint be'- tween said resistor and the other end of the tube.
2. A heating element comprising azig-zag resistor member of carbonaceous material, an open top receptacle of silicon carbide or like refractory material in which said member is housed, a packu ing between said receptacle and said member in which said member is embedded, said packing comprising a mixture of fire sand, powdered coke and a fusible material, a cementitious covering providing a gas-tight seal over the open top of the receptacle, and conducting terminals embedded at their ends in said packing material and projecting outward from said resistor member, said terminals comprising tubular sheaths, and means providing gas-tight seals at the outer ends of said tubular sheaths.
3. A heating element comprising a zig-zag resistor member of carbonaceous material, an opentop receptacle of silicon carbide or like refractory material in which said member is housed, a packing between said receptacle and said member in which said member is* embedded, said packingA comprising a mixture of fire sand, powdered coke and a fusible material, a cementitious covering providing a gas-tight seal over the open top of the receptacle, and conducting terminals comprising carbonaceous rods and enclosing refractory tubes, the ends of said tubes being embedded in said packing.
4. A heating element comprising a carbonaceous resistance member, a container therefor of refractory material, said container having an open top, conducting terminals comprising carbonaceous rods, refractory tubes enclosing said rods, metallic glands into which the outer ends of said tubes are cemented, and a refractory packing completely covering said resistance member, and a cementitious covering providing a top for said container, 'the end portions of said tubes being embedded in said covering.
5,. A heating element comprising a carbonaceous resistance member, a container therefor of refractory material, said container having an open top, conducting terminals comprising carbonaceous rods, refractory tubes enclosing said rods, metallic glands into which the outer ends of said tubes are cemented, and a refractory packing completely covering said resistance member and a refractory cover providing a top for said container, the end portions of said tubes being cemented in said cover.
RODERICK L. HARPER. ROBERT MACDONALD, JR.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US618844A US2009732A (en) | 1932-06-23 | 1932-06-23 | Electric resistor |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US618844A US2009732A (en) | 1932-06-23 | 1932-06-23 | Electric resistor |
Publications (1)
Publication Number | Publication Date |
---|---|
US2009732A true US2009732A (en) | 1935-07-30 |
Family
ID=24479356
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US618844A Expired - Lifetime US2009732A (en) | 1932-06-23 | 1932-06-23 | Electric resistor |
Country Status (1)
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US (1) | US2009732A (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2553762A (en) * | 1946-11-01 | 1951-05-22 | Gyuris John | Electrical heating element and method of making the same |
US2640861A (en) * | 1950-11-27 | 1953-06-02 | Harshaw Chem Corp | Resistance furnace |
US2744152A (en) * | 1954-10-28 | 1956-05-01 | Gen Electric | Electric furnace with carbonaceous atmosphere |
US3307111A (en) * | 1963-11-22 | 1967-02-28 | Air Reduction | Molded composition resistor with parallel leads |
US3506771A (en) * | 1968-10-10 | 1970-04-14 | Stephen F Cole Jr | Modularly constructed heating elements for electric furnaces |
US20020093417A1 (en) * | 2000-10-20 | 2002-07-18 | Reiner Gross | Electrical resistor with thermal voltage prevention |
US6441718B1 (en) * | 1999-12-21 | 2002-08-27 | Vishay Dale Electronics, Inc. | Overlay surface mount resistor |
-
1932
- 1932-06-23 US US618844A patent/US2009732A/en not_active Expired - Lifetime
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2553762A (en) * | 1946-11-01 | 1951-05-22 | Gyuris John | Electrical heating element and method of making the same |
US2640861A (en) * | 1950-11-27 | 1953-06-02 | Harshaw Chem Corp | Resistance furnace |
US2744152A (en) * | 1954-10-28 | 1956-05-01 | Gen Electric | Electric furnace with carbonaceous atmosphere |
US3307111A (en) * | 1963-11-22 | 1967-02-28 | Air Reduction | Molded composition resistor with parallel leads |
US3506771A (en) * | 1968-10-10 | 1970-04-14 | Stephen F Cole Jr | Modularly constructed heating elements for electric furnaces |
US6441718B1 (en) * | 1999-12-21 | 2002-08-27 | Vishay Dale Electronics, Inc. | Overlay surface mount resistor |
US20020093417A1 (en) * | 2000-10-20 | 2002-07-18 | Reiner Gross | Electrical resistor with thermal voltage prevention |
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