JP2010236822A - Heating rotary furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heating rotary furnace expecting improvement of heat efficiency. <P>SOLUTION: This heating rotary furnace 10 includes a rotary furnace 12 composed of a magnetic material, and a coil 42 disposed at its outer side. High-frequency power supplied from a high-frequency power source 44 is generated from the coil 42. Induction current is generated at a peripheral side face of the rotary furnace 12 by the high-frequency power, and the peripheral side face of the rotary furnace 12 produces heat by the induction current. The heat is diffused in the rotary furnace 12, thus the inside of the rotary furnace is heated. As a result, the peripheral side face of the rotary furnace produces heat, and heat efficiency is improved. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a heating rotary furnace and, for example, relates to a heating rotary furnace that heats powder and the like.

  An example of this type of heating rotary furnace is disclosed in Patent Document 1. In the heating rotary furnace shown in Patent Document 1, a vacuum furnace made of stainless steel or molybdenum alloy is rotated around its axis, and the inside of the furnace is heated by a cylindrical body heating means arranged coaxially with the vacuum furnace and surrounding the vacuum furnace. Heat.

JP 2006-284052 A [F27B 7/06 B22F 1/00 F27B 7/12 F27B 7/24]

  The heating rotary furnace disclosed in Patent Document 1 has a problem that the heat efficiency is not necessarily good because the heating means is for heating the inside of the furnace away from the rotary furnace.

  Therefore, the main object of the present invention is to provide a novel heating rotary furnace.

  Another object of the present invention is to provide a heating rotary furnace that can be expected to improve thermal efficiency.

  The present invention employs the following configuration in order to solve the above problems. The reference numerals in parentheses, supplementary explanations, and the like indicate correspondence with the embodiments described later in order to help understanding of the present invention, and do not limit the present invention.

  A first invention is a heating rotary furnace including a rotary furnace including at least a part of a magnetic material and rotatably supported, and high-frequency magnetic field lines generating means provided outside the rotary furnace and generating high-frequency magnetic field lines .

  In the first invention, the heating rotary furnace (10: reference numerals exemplifying corresponding parts in the embodiment, hereinafter the same) includes a rotary furnace (12), and this rotary furnace is at least partially made of a magnetic material. It is formed including. For example, the high-frequency magnetic field line generating means such as the coil (42) receives high-frequency power from a high-frequency power source and generates high-frequency magnetic field lines around it. The magnetic material present in at least a part of the rotary furnace is electromagnetically coupled to the high-frequency magnetic field lines, whereby an induced current (eddy current) is generated in the magnetic material portion by the high-frequency magnetic field lines. Joule heat is generated by the induced current, and the heat is dissipated inside the rotary furnace. Therefore, the inside of the rotary furnace is heated by the heat generated by the induced current.

  According to the first invention, since the rotary furnace itself generates heat by the induced current, the thermal efficiency is better than indirect heating means as in the background art. Therefore, a heating rotary furnace can be comprised compactly as a whole.

  A second invention is a heating rotary furnace according to the first invention, wherein the rotary furnace is formed of a magnetic material as a whole.

  In the second invention, since the rotary furnace (12) is formed of a magnetic material as a whole, heat can be generated in a wide range.

  A third invention is a heating rotary furnace according to the first invention, wherein the rotary furnace is formed of a nonmagnetic material as a whole and includes a magnetic material in part.

  In the third invention, since the magnetic material is partially included, the range of heat generation can be limited to the magnetic material portion.

  A fourth invention is dependent on any one of the first to third inventions, wherein the high-frequency magnetic field line generating means includes a coil provided around the rotary furnace, and is made of a nonmagnetic material, and holds the coil fixedly. It is a heating rotary furnace provided with a holding means.

  In the fourth invention, the high-frequency magnetic field line generating means includes a coil (42) wound around the entire circumference of the rotary furnace (12) or folded only in a part of the circumferential direction or formed in a spiral shape. . The coil (42) is formed of a holding means made of a non-magnetic material, for example, an annular body surrounding the rotary furnace in a part in the height direction of the rotary furnace (12). Such holding means holds the coil (42) fixedly.

  A fifth invention is a heating rotary furnace according to the fourth invention, wherein the holding means includes a jacket formed of a nonmagnetic material and surrounding the rotary furnace as a whole.

  In the fifth invention, since the outer cover (46) constituting the holding means surrounds the rotary furnace (12) as a whole, the outer surface of the rotary furnace (12) is almost completely thermally isolated from the atmosphere. Therefore, heat dissipation from the outer surface of the rotary furnace (12) is suppressed, and the thermal efficiency is further enhanced.

  According to the present invention, since heat can be directly applied to the rotary furnace, the thermal efficiency is improved.

  The above object, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

FIG. 1 is an illustrative view showing one embodiment of a heating rotary furnace of the present invention. FIG. 2 is an illustrative view showing a cross-sectional structure of a heating rotary furnace of this embodiment. FIG. 3 is a sectional view showing another embodiment of the present invention. FIG. 4 is an illustrative sectional view showing another embodiment of the present invention.

  1 and 2, a heating rotary furnace 10 according to an embodiment of the present invention includes a rotary furnace 12, and the rotary furnace 12 has a bottomed cylindrical shape, and a hole 16 is formed in a bottom portion 14 thereof. Then, one end of an air pipe 18 made of a metal such as iron or stainless steel faces the hole 16. Therefore, air of a predetermined temperature is supplied from the air pipe 18 into the rotary furnace 12. For example, low temperature air is supplied from the air pipe 18 when it is desired to lower the furnace temperature, and heated air is supplied when it is not desired to lower the furnace temperature at least.

  However, it is also possible to provide a refrigerant pipe in the rotary furnace 12 and flow a refrigerant such as water through the refrigerant pipe (not shown) to lower the furnace temperature.

  An appropriate lid 20 is attached to the rotary furnace 12 so as to be openable and closable. An exhaust pipe 22 is provided in a part of the lid 20 so as to communicate with the inside of the rotary furnace 12. The exhaust pipe 22 is normally sealed and opened when necessary to discharge gas from the rotary furnace 12.

  In this embodiment, the rotary furnace 12 is formed of a magnetic material such as iron as a whole including the bottom portion 14, and the air pipe 18 is fixed to the bottom portion 14 of the rotary furnace 12. However, the lid 20 may be formed of either a magnetic material or a non-magnetic material.

  A metal block 24 such as iron is fixed to the outer periphery of one end side of the air pipe 18 by an appropriate means such as welding or brazing. An appropriate number of screw holes (female screws) are formed on the upper surface of the metal block 24, and a bolt 26 penetrating the bottom portion 14 of the rotary furnace 12 is screwed into the screw hole, so that the metal block 24 becomes the bottom surface of the bottom portion 14. It is fixed to. Therefore, the air pipe 18 having the metal block 24 integrally attached to the outer periphery thereof is fixed to the bottom surface of the bottom portion 14 of the rotary furnace 12 via the metal block 24.

  The air pipe 18 is rotatably supported by a bearing 28 such as a ball bearing, for example, at two positions spaced apart in the axial direction thereof. Although not shown in detail, these bearings 28 are fixedly supported by a mounting base 29 made of metal such as iron shown in FIG. Since the air tube 18 is fixed to the rotary furnace 12 as described above, the rotary furnace 12 is eventually rotatably supported by the bearing 28 fixed to the mounting base 29. It functions as a rotating shaft of the rotary furnace 12. However, there is a gap between the mounting base 29 and the air pipe 18, so that the mounting base 29 is not contacted when the air pipe 18 rotates.

  Further, as can be seen from FIG. 2, since the upper surface of the mounting base 29 is inclined downward to the right, the shaft of the bearing 28 fixed to the upper surface is inclined to the right according to the inclination. Therefore, the air pipe 18 as a rotating shaft inserted through the bearing 28 is also inclined to the right, and the rotary furnace 12 supported by the inclined rotating shaft is also inclined to the right. Therefore, when the rotary furnace 12 rotates about the air tube 18 as a rotation axis, the object to be processed such as powder accommodated in the rotary furnace 12 is regularly displaced up and down, thereby naturally. Stir. However, a stirring means such as a stirring blade can be provided in the rotary furnace 12 in order to positively impart a stirring function.

  A pulley 30 is fixed to the outer periphery of the air pipe 18 between the two bearings 28, and a belt 38 is stretched between the pulley 30 and a pulley 36 fixed to the output shaft 34 of the motor 32. Therefore, the rotary furnace 12 is rotated by the motor 32 around the air tube 18 as a rotation axis.

  An annular body 40 made of a non-magnetic material such as stainless steel or aluminum is fixedly provided so as to surround the outer periphery of the rotary furnace 12 at a distance from the outer periphery. A coil 42 is wound around the outer periphery of the annular body 40. The coil 42 is supplied with a high-frequency current from a high-frequency power supply 44, and thus a high-frequency magnetic field line is generated from the coil 42. That is, the coil 42 functions as a high-frequency magnetic field line generating unit, and the annular body 40 functions as a holding unit for the high-frequency magnetic field line generating unit.

  High-frequency magnetic field lines generated from the coil 42 generate eddy current (inductive current) on the peripheral side surface of the rotary furnace 12 made of a magnetic material and magnetically coupled to the coil 42. The eddy current generates heat on the peripheral surface of the rotary furnace 12 itself. The generated heat is dissipated as it is inside the rotary furnace 12, and therefore the inside of the rotary furnace 12 is directly heated. Therefore, an object to be processed, such as powder, placed in the rotary furnace 12 can be efficiently heated.

  For example, a temperature sensor (not shown) such as a thermocouple is arranged inside the rotary furnace 12, for example, the temperature in the furnace is measured by this temperature sensor, and the high frequency power from the high frequency power supply 44 is controlled based on the temperature. If the duty ratio (on / off duty ratio or output power amount) is changed, the high-frequency magnetic field lines generated from the coil 42 change, and the in-furnace temperature of the rotary furnace 12 can be directly controlled.

  In the above-described embodiment, the rotary furnace 12 is formed of a magnetic material as a whole. Therefore, if the range covered by the high-frequency magnetic field lines of the coil 42 is widened, heat can be generated in a wide range.

  Another embodiment of the invention is shown in FIG. Referring to FIG. 3, the heating rotary furnace 10 of this embodiment is the same as the previous embodiment described in FIGS. 1 and 2 except for the points described below, and redundant description is omitted here. .

  In the heating rotary furnace 10 of the embodiment of FIG. 3, the rotary furnace 12, which is mostly exposed in the previous embodiment shown in FIGS. 1 and 2, has a bottomed cylindrical shape similar to the rotary furnace 12. Covered by the outer cover 46 to be formed. The inner surface of the outer side surface of the outer cover 46 is separated from the outer surface of the peripheral side surface of the rotary furnace 12, and the bottom portion 48 and the bottom portion 14 are also separated, and the metal block 24 is disposed therebetween. The outer cover 46 is formed of a non-magnetic material such as stainless as a whole, and a lid 50 is provided on the open side thereof so that it can be opened and closed. In the heating rotary furnace 10 of this embodiment, since the cover body 50 is provided on the jacket 46 as described above, the rotary furnace 12 is completely covered with the jacket 46 and the cover body 50. Therefore, the outer surface of the rotary furnace 12 is almost completely thermally shut off from the atmosphere. Therefore, heat dissipation from the outer surface of the rotary furnace 12 is suppressed, and the thermal efficiency is further enhanced.

  Then, the coil 42 is wound around the outer periphery of the corresponding place of the jacket 46. Therefore, as in the previous embodiment, eddy currents are generated in the rotary furnace 12 by the high-frequency magnetic field lines generated from the coil 42, and the rotary furnace 12 itself generates heat.

  Since the rotary furnace 12 is completely covered with the jacket 46 and the lid 50, the lid 20 used in the previous embodiment is omitted in this embodiment.

  Further, in the embodiment of FIG. 3, the exhaust pipe 52 is provided on a part of the peripheral side surface on the open side of the jacket 46. The exhaust pipe 52 communicates with a gap between the rotary furnace 12 and the jacket 46, and exhausts gas discharged from the open side of the rotary furnace 12 through the gap.

  In this embodiment, a temperature sensor 54 is preferably disposed inside the exhaust pipe 52. The temperature of the exhaust gas is measured by the temperature sensor 54, and the high frequency power generated by the coil 42 is controlled by controlling the high frequency power from the high frequency power supply 44 (on / off duty ratio and output power amount) according to the measured temperature. It is possible to control the temperature in the rotary furnace 12 indirectly.

  Referring to FIG. 4, this figure illustrates another embodiment of the present invention. The heating rotary furnace 10 of this embodiment is the same as the embodiment shown in FIG. 1 and FIG. 2 or the embodiment shown in FIG. 3 except for the points described below, and redundant description is omitted here.

  In any of the previous embodiments, the entire rotary furnace 12 is made of a magnetic material such as iron. However, in this embodiment, the rotary furnace 12 is made entirely of a nonmagnetic material such as stainless steel. Then, a magnetic body 56 made of a magnetic material is fixed to the inner surface (or the outer surface) of the peripheral side surface of the rotary furnace 12. Therefore, no induced current is generated in the non-magnetic material portion forming the rotary furnace 12 with respect to the high-frequency magnetic field lines from the coil 42. However, when the induced current is generated in the magnetic body 56, the magnetic body 56 generates heat. Heat is radiated into the furnace and the furnace is heated.

  Thus, it is not necessary to form the whole rotary furnace 12 with a magnetic material, and it should just be formed including a magnetic material at least partially. Since the vicinity of the portion formed of the magnetic material is efficiently heated, in the embodiment in which only a part of the rotary furnace 12 is formed of the magnetic material, the magnetic material may be disposed in the portion to be heated. . By doing so, heat can be generated only at the necessary portion, that is, the range of heat generation can be limited to the portion of the magnetic material, and further improvement in thermal efficiency can be expected.

  In each of the embodiments described above, the coil constituting the high-frequency magnetic field line generating means is wound around the rotary furnace 12, but the coil need not be wound around the rotary furnace, Only a part in the circumferential direction may be folded or spirally formed.

  Further, in each of the above-described embodiments, since the air tube 18 is used as the rotating shaft of the rotary furnace 12, the structure is simple and can be reduced in size as compared with a case where another air tube is provided, but the air tube is unnecessary. In this case, or when it is better to provide an air tube at another location, the air tube 18 may be replaced with a solid shaft and function only as a rotating shaft.

  In addition, each of the embodiments described above is independent, but another embodiment can be configured by appropriately combining each component or element (component). For example, the rotary furnace 12 of the embodiment of FIG. 4 is replaced with the rotary furnace of the embodiment of FIGS.

DESCRIPTION OF SYMBOLS 10 ... Heating rotary furnace 12 ... Rotary furnace 18 ... Air pipe 28 ... Bearing 32 ... Motor 42 ... Coil 44 ... High frequency power supply 46 ... Jacket 56 ... Magnetic body

Claims (5)

A heating rotary furnace comprising: a rotary furnace including at least a part of a magnetic material and rotatably supported; and high-frequency magnetic field lines generating means provided outside the rotary furnace to generate high-frequency magnetic field lines.   The heating rotary furnace according to claim 1, wherein the rotary furnace is formed of a magnetic material as a whole.   The heating rotary furnace according to claim 1, wherein the rotary furnace is formed of a nonmagnetic material as a whole and includes a magnetic material in part. The heating according to any one of claims 1 to 3, wherein the high-frequency power generation means includes a coil provided around the rotary furnace, and further includes a holding means that is made of a nonmagnetic material and holds the coil fixedly. Rotary furnace.   The heating rotary furnace according to claim 4, wherein the holding means is formed of a nonmagnetic material, and includes a jacket that surrounds the rotary furnace with all materials.

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