Rotary bed-type electric furnace

Patent metadata

Field	Value
Publication number	US-10746467-B2
Application number	US-202016743387-A
Country	US
Kind code	B2
Filing date	Jan 15, 2020
Priority date	Jul 21, 2017
Publication date	Aug 18, 2020
Grant date	Aug 18, 2020

Abstract

A rotary bed-type electric furnace includes a rotary bed configured to carry material, and a rotator configured to rotate the rotary bed so that material carried on the rotary bed passes through peripheral zones of the rotary bed-type electric furnace. The peripheral zones include a feeding zone configured to receive material on the rotary bed, a drying zone configured to dry and heat material by means of electrical energy, a heating zone configured to heat material by means of electrical energy, a cooling zone configured to lower the temperature of the material and configured to release gases from the material, and a discharging zone configured to discharge material from the rotary bed of the furnace.

First claim

The invention claimed is:

1. A rotary bed electric furnace, comprising:
a rotary bed having a material carrying surface configured to carry material to be heated in the rotary bed electric furnace, and
a rotator configured to rotate the rotary bed so that material carried on the material carrying surface of the rotary bed passes through peripheral zones of the rotary bed electric furnace,
wherein the peripheral zones include:
a feeding zone configured to receive the material on the material carrying surface of the rotary bed,
a drying zone configured to receive the material carried on the material carrying surface of the rotary bed from the feeding zone and configured to dry and heat the material carried on the material carrying surface of the rotary bed by means of electrical energy to a temperature between 50 and 300° C.,
a heating zone configured to receive the material carried on the material carrying surface of the rotary bed from the drying zone and configured to heat the material carried on the material carrying surface of the rotary bed by means of electrical energy to a temperature between 300 and 700° C.,
a cooling zone configured to receive the material carried on the material carrying surface of the rotary bed from the heating zone and configured lower the temperature of the material carried on the material carrying surface of the rotary bed and configured to release gases from the material carried on the material carrying surface of the rotary bed, and
a discharging zone configured to receive the material carried on the material carrying surface of the rotary bed from the cooling zone and configured to discharge the material carried on the material carrying surface of the rotary bed from the material carrying surface of the rotary bed,
the drying zone being covered by a first section hood configured to prevent gases from escaping from the drying zone,
the heating zone being covered by a second hood section configured to prevent gases from escaping from the heating zone,
the cooling zone being covered by a third hood section configured to prevent gases from escaping from the cooling zone, wherein the first, second, and third hood sections are fixed relative to the drying, heating, and cooling zones, respectively, such that the rotary bed is configured to rotate relative to the first, second, and third hood sections,
a first curtain arrangement between the feeding zone and the drying zone to prevent exhaust gases from escaping from the furnace between the feeding zone and the drying zone, and
a second curtain arrangement between the cooling zone and the discharging zone to prevent exhaust gases from escaping from the furnace between the cooling zone and the discharging zone.

2. The rotary bed electric furnace according to claim 1 , wherein the rotator is configured to rotate the rotary bed at a rotating speed that is steplessly adjustable.

3. The rotary bed electric furnace according to claim 1 , wherein the drying zone is thermally insulated with insulation.

4. The rotary bed electric furnace according to claim 1 , wherein the heating zone is thermally insulated with insulation.

5. The rotary bed electric furnace according to claim 1 , wherein the drying zone is provided with first exhaust ducts configured to lead vaporized matter formed in connection with the drying of the material carried on the material carrying surface of the rotary bed from the drying zone.

6. The rotary bed electric furnace according claim 1 , wherein the heating zone is provided with an oxygen containing gas feeding system configured to feed oxygen containing gas into the heating zone.

7. The rotary bed electric furnace according to claim 1 , wherein the heating zone is provided with second exhaust gas ducts configured to lead exhaust gas formed in connection with the heating of the material carried on the material carrying surface of the rotary bed from the heating zone.

8. The rotary bed electric furnace according claim 1 , wherein the cooling zone is provided with third exhaust gas ducts configured to lead exhaust gas formed in connection with the cooling of the material carried on the material carrying surface of the rotary bed from the cooling zone.

9. The rotary bed electric furnace according to claim 1 , wherein the discharging zone comprises discharging means comprising a knife or a brush or the like scraper means configured to remove the material from the material carrying surface of the rotary bed.

10. The rotary bed electric furnace according to claim 1 , wherein the discharging zone comprises discharging means comprising a vacuum arrangement configured to remove the material from the material carrying surface of the rotary bed.

11. The rotary bed electric furnace according to claim 1 , wherein the feeding zone comprises a feeding arrangement provided with an elongated material feeding aperture extending transversely above the rotary bed.

12. The rotary bed electric furnace according to claim 1 , wherein:
the heating zone comprises a combustion section at a downstream end of the heating zone, and
the combustion section of the heating zone being configured to combust material in presence of oxygen containing gas.

13. The rotary bed electric furnace according to claim 1 , further comprising an analyzing apparatus configured to analyze at least one of a color of the material or a content of the exhaust gases.

14. The rotary bed electric furnace according to claim 13 , wherein the discharging zone is configured to not remove the material from the rotary bed upon the analyzing apparatus determining that a combustion of the material has not occurred to a threshold extent.

15. The rotary bed electric furnace according to claim 14 , wherein the feeding zone is configured to not feed new material onto the rotary bed upon the analyzing apparatus determining that the combustion of the material has not occurred to the threshold extent.

16. The rotary bed electric furnace according to claim 1 , wherein the material carrying surface is flat and annular.

17. A rotary bed electric furnace, comprising:
a rotary bed having a material carrying surface configured to carry material to be heated in the rotary bed electric furnace, and
a rotator configured to rotate the rotary bed so that material carried on the material carrying surface of the rotary bed passes through peripheral zones of the rotary bed electric furnace,
wherein the peripheral zones include:
a feeding zone configured to receive the material on the material carrying surface of the rotary bed,
a drying zone configured to receive the material carried on the material carrying surface of the rotary bed from the feeding zone and configured to dry and heat the material carried on the material carrying surface of the rotary bed by means of electrical energy to a temperature between 50 and 300° C.,
a heating zone configured to receive the material carried on the material carrying surface of the rotary bed from the drying zone and configured to heat the material carried on the material carrying surface of the rotary bed by means of electrical energy to a temperature between 300 and 700° C.,
a cooling zone configured to receive the material carried on the material carrying surface of the rotary bed from the heating zone and configured lower the temperature of the material carried on the material carrying surface of the rotary bed and configured to release gases from the material carried on the material carrying surface of the rotary bed, and
a discharging zone configured to receive the material carried on the material carrying su

Assignees

• Outotec Finland Oy

Inventors

• Halkola Jari
• Kurki Seija
• Lillkung Kristian

Classifications

• F27D2019/0003

  Monitoring the temperature or a characteristic of the charge and using it as a controlling value · CPC title

• F27D99/0073

  Seals · CPC title

• F27B9/16 Primary

  the charge moving in a circular or arcuate path · CPC title

• C21B13/08

  in rotary furnaces · CPC title

• C22B5/10

  by solid carbonaceous reducing agents · CPC title