US3060304A - Electric direct heating method of heating metallic pieces - Google Patents

Electric direct heating method of heating metallic pieces Download PDF

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Publication number
US3060304A
US3060304A US847371A US84737159A US3060304A US 3060304 A US3060304 A US 3060304A US 847371 A US847371 A US 847371A US 84737159 A US84737159 A US 84737159A US 3060304 A US3060304 A US 3060304A
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United States
Prior art keywords
piece
heating
heated
fluidized
electro
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Expired - Lifetime
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US847371A
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English (en)
Inventor
Tanaka Yukio
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
TO A KAKO KK
TO-A KAKO KK
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TO A KAKO KK
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    • 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
    • H05B3/60—Heating arrangements wherein the heating current flows through granular powdered or fluid material, e.g. for salt-bath furnace, electrolytic heating
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
    • B01J8/18—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with fluidised particles
    • B01J8/24—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with fluidised particles according to "fluidised-bed" technique
    • B01J8/42—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with fluidised particles according to "fluidised-bed" technique with fluidised bed subjected to electric current or to radiations this sub-group includes the fluidised bed subjected to electric or magnetic fields
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/34—Methods of heating
    • C21D1/40—Direct resistance heating
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/34—Methods of heating
    • C21D1/53—Heating in fluidised beds
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
    • C21D9/54—Furnaces for treating strips or wire
    • C21D9/56—Continuous furnaces for strip or wire
    • C21D9/62—Continuous furnaces for strip or wire with direct resistance heating
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B1/00—Preliminary treatment of ores or scrap
    • C22B1/02—Roasting processes
    • C22B1/10—Roasting processes in fluidised form
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C22F1/004—Heat treatment in fluid bed
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D13/00—Heat-exchange apparatus using a fluidised bed

Definitions

  • heating metallic pieces have been conventionally used salt baths, gas furnaces, induction heating furnaces and resistance furnaces.
  • a method of heating metallic pieces to be heated by self heat generation in them by directly flowing an electric current to them is lower in the cost required for the equipment, more efficient in heating and more economical than any of the above mentioned heating means.
  • a principal object of the present invention is to provide a heating method wherein, in heating a piece by self heat generation therein by an electric current flowing thereto, the current can be made to flow without causing sparks on the surface of the piece to be heated on which the current is flowing and, even though the current is made to flow, no damage will be caused to the surface of the piece to be heated.
  • Another object of the present invention is to provide a method of heating pieces to be heated by relatively uniformly flowing an electric current to them, even if the shapes of pieces to be heated are irregular.
  • a further object of the present invention is to provide a heating method wherein the heating temperature and the portion to be heated in a piece to be heated can be freely adjusted.
  • an electric direct heating method of metallic pieces characterized in dipping the metallic pieces to be heated in a bed of fluidized electro-conductive carbon powder, flowing an electric current through the bed of fluidized electro-conductive powder and the pieces, and adjusting the heating temperature of the portion in the pieces by controlling the intensity of the electric current.
  • the electro-conductive powder may be a carbon powder which can pass an electric current.
  • a bed of a fluidized electroconductive powder for example, a bottom wall made of such material which passes gases but does not pass the electro-conductive powder as a micro-porous tile plate is provided in the middle of a chamber, the electro-conductive powder is placed on the bottom wall and a gas or, for example, air under pressure is pressed in through an inlet provided in the bottom of the chamber, so that the electro-conductive powder may be fluidized.
  • the size of the particles of the electro-conductive powder depends on the specific gravity and fluidity of the material of said powder. In the case of a carbon powder, the size of 100 to 150 meshes per inch is desirable.
  • the gas to fluidize the electro-conductive powder depends on the volume of the chamber and the thickness and microporosity of the bottom Wall. Compressed air of about 4 to 10 kg./cm. is used. Such inert gas as nitrogen may be used in place of air.
  • an alternating, pulsating or direct current is used.
  • the fluidizing chamber containing the fluidized electro-conductive carbon powder is made of an electro-conductive material
  • an alternating or direct current voltage should be impressed between the fluidizing chamber and the piece to be heated, and the current intensity should be adjusted by a regulator belonging to the electric source. In such case, the current will flow into the piece through the fluidized electroconductive powder and the powder will act as an electric contact.
  • the electrodes may be dipped in the fluidized electroconductive powder and the voltage may be impressed between said electrodes and the piece to be heated.
  • FIGURE 1 is a vertically sectioned side view of an apparatus to be used in working the method of the present invention.
  • FIGURE 2 is a vertically sectioned principle view of an apparatus as used in working the method of continuously heating metallic wires, bars and tubes.
  • 1 is a fluidizing chamber made of an electro-conductive material and 2 is a micro-porous bottom wall made of a micro-porous material such as, for example, a micro-porous tile plate and provided in the middle bottom of said fluidizing chamber.
  • the microporous material of the bottom wall is such as passes gases but does not pass the electro-conductive powder.
  • 3 is an inlet for introducing compressed air and provided in the fluidizing chamber.
  • 4 is such piece to be heated as a metallic piece.
  • 5 is an alternating, direct or pulsating current source.
  • 6 is a regulator for adjusting the current intensity.
  • the electroconductive powder when electro-conductive carbon powder is contained in the fluidizing chamber 1 and compressed air is pressed in through the inlet 3, the electroconductive powder will be fluidized within the fluidizing chamber.
  • the piece 4 to be heated is dipped in the bed of the fluidized electro-conductive powder.
  • the switch 7 When the switch 7 is closed so as to impress the voltage on the piece 4 to be heated and the fluidizing chamber 1, an electric current will ilow thorugh the fluidized electroconductive powder.
  • the intensity of the current flowing to the piece to be heated is adjusted by the regulator 6.
  • the fluidized electro-conductive powder will be electrically charged and will therefore operate just the same as ions in a discharge tube so as to charge electricity.
  • the contact resistance between the fluidized electro-conductive powder and the surface of the metallic piece is so high that heat will be generated mainly due to Joules heat in these parts and also somewhat by the resistance of the electro-conductive powder itself and of the piece to be heated.
  • the surface-heating and through-heating of the piece to be heated will be possible. That is to say, if the current density is made lower, it will be possible to heat the whole of the piece to be heated and, if the current density is made higher, mainly the surface portion of the piece will be able to be heated.
  • 11 is a fluidizing chamber made of an electro-conductive material.
  • 12 is a micro-porous bottom wall made of a micro-porous material and provided in the middle bottom of the fluidizing chamber.
  • 13 is an inlet for introducing compressed air and provided in the fluidizing chamber.
  • 14 is such piece to be heated as a metallic wire.
  • .15 is a packing attached to the side wall of the fluidizing chamber so that the metallic Wire may flow through the central part of the packing. It is necessary that the electro-conductive powder should not leak out through the clearance between the packing and the metallic wire.
  • '16 is an alternating, pulsating or direct current source.
  • 17 is a regulator for adjusting the current intensity.
  • 18 is a switch.
  • the heating method shown in FIGURE 1 it is possible to heat the piece to be heated in a rotating state while rotating the piece around an axis provided on said piece as a centre. Further, instead of using the fluidizing chamber as one of the electrodes, it is possible to provide one or more electrodes in the bed of the fluidized electroconductive powder and to connect the electric source thereto.
  • the heating method according to the present invention can be extensively applied to heating or tempering wheels. and to continuously annealing piano wires, copper rods brass plates and so forth.
  • An electric direct method of heating electrically conductive metallic pieces characterized in dipping me-- tallic pieces to be heated in a bed of fluidized electro-- conductive carbon powder rotating the pieces around an. axis, flowing an electric current through the. bed of fluidized carbon powder to the piece, and adjusting the heating temperature of the piece being heated by controlling the current density at the surface of said metallic piece.
  • An electric direct method of heating relatively long metallic pieces, of uniform cross-section, including metal" wires, which are electrically conductive characterizedin maintaining a bed of carbon powder in fluidized state; passing the metallic piece through the bed of fluidized carbon powder, flowing an electric current through the bed of fluidized electro-conductive carbon powder to the. metallic piece, and adjusting the heating temperature of the metallic piece undergoing heating by control'lingthei current density of the electric current at the surface of the metallic piece being heated.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Thermal Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Metallurgy (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Manufacturing & Machinery (AREA)
  • Geology (AREA)
  • Geochemistry & Mineralogy (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • General Engineering & Computer Science (AREA)
  • Crucibles And Fluidized-Bed Furnaces (AREA)
US847371A 1959-07-22 1959-10-19 Electric direct heating method of heating metallic pieces Expired - Lifetime US3060304A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP3060304X 1959-07-22

Publications (1)

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US3060304A true US3060304A (en) 1962-10-23

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US847371A Expired - Lifetime US3060304A (en) 1959-07-22 1959-10-19 Electric direct heating method of heating metallic pieces

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US (1) US3060304A (en, 2012)
FR (1) FR1241387A (en, 2012)
NL (1) NL109946C (en, 2012)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3115569A (en) * 1960-12-14 1963-12-24 Johnson Matthey Co Ltd Production of powders of metal, alloy or other electrically conductive material
US3257116A (en) * 1962-01-08 1966-06-21 Polymer Corp Air seal structure for installation in an opening in a wall
US3448234A (en) * 1966-08-31 1969-06-03 Battelle Development Corp Electrical resistivity control of fluidized beds
US3925570A (en) * 1971-09-30 1975-12-09 Aeg Elotherm Gmbh Method of coating metallic material onto a metallic substrate
US4287406A (en) * 1977-09-08 1981-09-01 National Research Development Corporation Electric contact device with fluidized metal particle bed
US4587404A (en) * 1984-02-06 1986-05-06 Smith Marvin M Electrical thermal storage heat sink for space heater

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US441401A (en) * 1890-11-25 Mark w
US749418A (en) * 1904-01-12 Method of making carbon articles
FR689165A (fr) * 1930-01-31 1930-09-03 Procédé de chauffage des métaux et autres corps conducteurs d'électricité, en vue de la fusion, du soudage, de l'incandescence, etc.
GB801653A (en) * 1954-04-20 1958-09-17 Walter Reinecken Improvements in the thermal treatment of solid metallic articles or material by passage of current therethrough

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US441401A (en) * 1890-11-25 Mark w
US749418A (en) * 1904-01-12 Method of making carbon articles
FR689165A (fr) * 1930-01-31 1930-09-03 Procédé de chauffage des métaux et autres corps conducteurs d'électricité, en vue de la fusion, du soudage, de l'incandescence, etc.
GB801653A (en) * 1954-04-20 1958-09-17 Walter Reinecken Improvements in the thermal treatment of solid metallic articles or material by passage of current therethrough

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3115569A (en) * 1960-12-14 1963-12-24 Johnson Matthey Co Ltd Production of powders of metal, alloy or other electrically conductive material
US3257116A (en) * 1962-01-08 1966-06-21 Polymer Corp Air seal structure for installation in an opening in a wall
US3448234A (en) * 1966-08-31 1969-06-03 Battelle Development Corp Electrical resistivity control of fluidized beds
US3925570A (en) * 1971-09-30 1975-12-09 Aeg Elotherm Gmbh Method of coating metallic material onto a metallic substrate
US4287406A (en) * 1977-09-08 1981-09-01 National Research Development Corporation Electric contact device with fluidized metal particle bed
US4587404A (en) * 1984-02-06 1986-05-06 Smith Marvin M Electrical thermal storage heat sink for space heater

Also Published As

Publication number Publication date
FR1241387A (fr) 1960-09-16
NL109946C (en, 2012)

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