JP2020009628A - Optical heating type heater - Google Patents

Abstract

To provide an optical heating type heater capable of effectively heating liquids such as hydrofluoric acid and phosphoric acid while having high heating efficiency.SOLUTION: An optical heating type heater including a halogen lamp and a casing that hermetically surrounds the halogen lamp, and the casing includes a transmission unit that transmits light of the halogen lamp to the outside, and the transmission unit is formed of a fluororesin.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical heater.

  Conventionally, as a method of heating a fluid such as a liquid, for example, an energizing heater that generates heat by energizing a heating element formed of a coil-shaped heating wire, or a light equipped with a halogen lamp disposed inside a quartz tube. A method of heating a fluid such as a liquid using a heater or the like is known.

  The current-carrying heater is configured to transfer heat of a heating element generated by energization to a cover or the like disposed around the heating element, and then heat a liquid or the like existing outside the cover or the like. This is a heater that adopts a heat transfer system.

  Further, the light heating type heater directly heats a liquid or the like when light emitted from a halogen lamp is transmitted through a quartz tube, and generates a heat energy several times larger than that of a heat transfer method. This is a heater having an advantage that a liquid or the like can be efficiently heated because it can be applied to a heater.

  As described above, the electric heating type heater transfers the heat of the heating element to a cover or the like disposed around the heating element and then heats a liquid or the like existing outside the cover or the like. Therefore, there is a problem that the heating efficiency of the liquid or the like is low.

  In addition, although the light heating type heater has an advantage of high heating efficiency, the quartz tube containing the halogen lamp is easily broken, and if broken, contaminates a fluid such as a liquid to be heated. There was a problem. In addition, since the quartz tube has low durability against liquids such as hydrofluoric acid and phosphoric acid, a conventional optical heater cannot be used for heating these liquids. There was also the problem of having to adopt it.

  The present invention has been made in order to solve such a problem, and has an optical heating heater capable of effectively heating a liquid such as hydrofluoric acid and phosphoric acid while having high heating efficiency. The purpose is to provide.

  The object of the present invention is a light heating type heater including a halogen lamp and a casing that hermetically surrounds the halogen lamp, wherein the casing includes a transmission unit that transmits light of the halogen lamp to the outside. The light transmission type heater is characterized in that the transmission section is formed of a fluorine-based resin. In this light heating type heater, it is preferable to employ polytetrafluoroethylene (PTFE) as the fluorine-based resin, but it is not limited to this PTFE.

  Further, a configuration may be adopted in which a quartz tube is provided between the casing and the halogen lamp.

  Further, it is preferable that the quartz tube is disposed in close contact with the transmission portion of the casing.

  Further, the object of the present invention is a light heating type heater including a halogen lamp and a tubular casing for housing the halogen lamp therein, wherein the casing is provided between an inner tube and the inner tube. An outer tube arranged in a state where a space is formed, and a double-tube structure having an outer tube, and an inlet portion through which a fluid to be heated can flow into the space is provided at one end of the casing. The other end is provided with an outlet through which the fluid to be heated that has flowed into the space through the inlet can flow out, and the inner tube and the outer tube are formed of a fluorine-based resin. This is achieved by a light-heated heater characterized in that: In this light heating type heater, it is preferable to employ polytetrafluoroethylene (PTFE) as the fluorine-based resin, but it is not limited to this PTFE.

  Further, it may be configured to include a quartz tube disposed between the inner tube and the halogen lamp.

  Further, it is preferable that the quartz tube is arranged closely to the inner tube.

  In addition, a wall portion that connects the inner tube and the outer tube is provided, and the wall portion is disposed so as to spirally wind the surface of the inner tube, and is provided from the inlet portion to the outlet portion. It may be configured to define a spiral flow path extending toward it.

  Advantageous Effects of Invention According to the present invention, it is possible to provide an optical heating type heater capable of effectively heating a liquid such as hydrofluoric acid or phosphoric acid while having high heating efficiency.

FIG. 1A is a schematic configuration sectional view of a light heating type heater according to a first embodiment of the present invention, and FIG. 2B is a schematic configuration sectional view showing an AA section of FIG. (A) is a schematic structure sectional view showing a modification of the light heating type heater concerning a 1st embodiment of the present invention, and (b) is a schematic structure sectional view showing BB section of (a). is there. It is a schematic structure sectional view of a light heating type heater concerning a 2nd embodiment of the present invention. FIG. 4 is a schematic configuration sectional view showing a CC section of FIG. 3. FIG. 4 is a schematic configuration sectional view showing a DD section of FIG. 3. It is a schematic structure sectional view showing the modification of the light heating type heater concerning a 2nd embodiment of the present invention. FIG. 7 is a schematic configuration sectional view showing an EE section of FIG. 6. It is a schematic structure sectional view showing other modifications of a light heating type heater concerning a 2nd embodiment of the present invention.

  Hereinafter, a first embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1A is a schematic configuration sectional view of an optical heating type heater according to a first embodiment of the present invention, and FIG. 1B is a schematic configuration sectional view showing an AA section in FIG. FIG. The light heating type heater 1 according to the first embodiment is a throw-in type heater which is used by being introduced into a liquid which is a fluid to be heated, and is shown in FIGS. 1A and 1B. As shown in FIG. 1, it is configured to include a halogen lamp 2 and a casing 3 that hermetically surrounds the halogen lamp 2.

  The halogen lamp 2 is a heating source, and for example, a parallel light type halogen lamp 2 capable of heating a fixed area in a short time, a condensing type halogen lamp capable of locally heating, or the like can be used. In the present embodiment, as the halogen lamp 2, a parallel light type halogen lamp 2 having a long rod-shaped irradiation unit 21 for irradiating light is used. The halogen lamp 2 is connected to a control device (not shown), and based on a temperature measured by a temperature sensor (not shown) such as a thermocouple installed in the casing 3 or on the outer surface of the casing 3, the heat of the halogen lamp 2 is measured. It is configured to control the output. The control method of heat output may be automatic control or manual control operated by a person.

  1 (a) and 1 (b), the light heating type heater 1 is configured to include a single halogen lamp 2, but is configured to include several halogen lamps 2. May be. When a plurality of halogen lamps 2 are provided, the heat output of each lamp may be controlled independently, or the heat output may be controlled using all the lamps as one control unit.

  The casing 3 is a member that accommodates the halogen lamp 2 therein, and is a member that hermetically surrounds the halogen lamp 2 so that the fluid to be heated as a heating target does not directly contact the halogen lamp 2. The casing 3 is formed in a tubular shape in which one end 3a and the other end 3b are closed. One end of the halogen lamp 2 is fixed to one end 3 a of the cylindrical casing 3, and a predetermined distance is provided between the inner peripheral surface of the casing 3 and the surface of the irradiation unit 21 of the halogen lamp 2. The irradiation unit 21 is provided so as not to contact the inner peripheral surface of the casing 3. A through hole is formed in one end 3a of the casing 3 to which one end of the halogen lamp 2 is fixed, and power supply wiring and control wiring of the halogen lamp 2 are connected to the outside of the casing 3 through the through hole. It has a structure to be pulled out. The through holes are sealed with a heat-resistant resin material, and the drawn-out wirings are also covered with a heat-resistant resin material. As such a resin material, a resin material forming the casing 3 described later can be used.

  This casing 3 is formed from a fluororesin. Examples of the fluorine-based resin include polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkylvinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ethylene-tetrafluoroethylene Copolymer (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), tetrafluoroethylene-hexafluoropropylene-perfluoroalkylvinyl ether copolymer (EPE), and the like can be given. In the present embodiment, the casing 3 is formed by using, among the above-mentioned fluorine-based resin materials, particularly tetralithoethylene (PTFE; melting point: 330 ° C.) having high heat resistance.

  Further, the cylindrical portion of the casing 3 constitutes a transmission section 31 for transmitting the light of the halogen lamp 2 to the outside.

  The light heating type heater 1 having such a configuration is used, for example, by being thrown into a storage tank in which a liquid to be heated (a fluid to be heated) is stored. The light emitted from the halogen lamp 2 is transmitted through the fluororesin transmitting portion 31 of the casing 3 without being absorbed, and directly heats the liquid (fluid to be heated). Since the casing 3 is formed of a fluorine-based resin material, its heat-resistant temperature is about 200 ° C. to 300 ° C., while the surface temperature of the halogen lamp 2 is, for example, about 600 ° C. to 800 ° C. Although the temperature reaches the temperature, while the light heater 1 is immersed in the liquid being heated (fluid to be heated), the liquid (fluid to be heated) in contact with the surface of the casing 3 is Since the heat of the casing 3 is strongly removed, there is no possibility that the temperature of the casing 3 exceeds the heat-resistant temperature and is melted.

  The light heating type heater 1 according to the first embodiment of the present invention directly heats a liquid (fluid to be heated) by the light emitted from the halogen lamp 2 as described above, and thus has a high heating efficiency. -Since the casing 3 is made of a fluorine-based resin while having a heating ability, the casing 3 is not corroded by a liquid such as hydrofluoric acid, phosphoric acid, or a strong alkali, and these liquids are used. It becomes possible to heat. Further, when heating ultrapure water, in the case of a heater provided with a conventional quartz tube as a casing, elution of components in the quartz tube (quartz glass) becomes a problem, but in the case of the light heater 1 according to the present invention, Since the problem of elution of the components of quartz glass does not occur, it is suitable for heating ultrapure water. In addition, since the casing 3 is made of a fluorine resin, the casing 3 is resistant to external impacts and can effectively prevent the light heater 1 from being damaged.

  As described above, the light heating type heater 1 according to the first embodiment of the present invention has been described, but the specific configuration of the light heating type heater 1 is not limited to the above embodiment. For example, as shown in the schematic cross-sectional view of FIG. 2A and the schematic cross-sectional view of FIG. You may comprise so that the quartz tube 5 may be provided. The quartz tube 5 is a tubular body having excellent light transmittance and heat resistance, and is disposed at least at a position (opposing position) corresponding to the cylindrical portion (irradiation portion 21) of the halogen lamp 2. One end of the quartz tube 5 is connected and fixed to one end 3 a of the casing 3 and housed inside the casing 3. In addition, it is preferable that the quartz tube 5 is arranged closely to at least the transmission part 31 of the casing 3.

  Here, since the casing 3 of the light heating type heater 1 according to the present invention is formed of a fluorine-based resin material, as the temperature increases, the casing 3 is softened and easily deformed. In such a state, when the liquid pressure of the liquid to be heated (the fluid to be heated) is applied to the casing 3, a part of the casing 3 may be deformed inward and approach the halogen lamp 2. If the deformation becomes large and the deformed portion of the casing 3 comes into contact with the surface of the irradiation part 21 of the halogen lamp 2, the casing 3 may be damaged or damaged. However, by disposing the quartz tube 5 between the inner surface of the casing 3 and the irradiation part 21 of the halogen lamp 2, it is assumed that a deformation such that a part of the casing 3 approaches the irradiation part 21 of the halogen lamp 2 occurs. In this case, the quartz tube 5 functions as a stopper that supports the casing 3 and suppresses the deformation, and the deformed portion of the casing 3 may come into contact with the surface of the irradiation unit 21 of the halogen lamp 2. It is possible to effectively suppress the occurrence of the damage and prevent the casing 3 from being damaged or damaged.

  In particular, when a configuration is adopted in which the quartz tube 5 is arranged so as to be in close contact with at least the transmission part 31 in the casing 3, it is possible to prevent the deformation itself associated with the softening of the casing 3.

  Further, in the first embodiment, the entire casing 3 is formed from a fluororesin. However, the present invention is not particularly limited to such a configuration. The transmitting portion 31 to be transmitted is made of a fluororesin, and the portion other than the transmitting portion 31 is made of a material other than the fluororesin having corrosion resistance to liquids such as hydrofluoric acid, phosphoric acid, and strong alkali. You may.

  Further, in the first embodiment, the apparatus is configured to include the device for controlling the heat output of the halogen lamp 2 and the temperature sensor. However, the control device and the temperature sensor are omitted, and the light heating type heater 1 is omitted. You may comprise. When such a configuration is adopted, the temperature of the liquid to be heated (the fluid to be heated) may be measured, and the ON / OFF operation of the light heater 1 may be performed.

  Next, a second embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 3 is a schematic configuration cross-sectional view of a light heating type heater 1 according to a second embodiment of the present invention, and FIG. 4 is a schematic configuration cross-sectional view showing a CC section in FIG. The light heating type heater 1 according to the second embodiment is different from the throw-in type heater according to the first embodiment in that it is an internal passage heating type heater in which a liquid (a fluid to be heated) is passed and heated. In addition, as shown in FIGS. 3 and 4, it is configured to include a halogen lamp 2, a casing 3 for housing the halogen lamp 2 therein, and an outer casing 6 further surrounding the casing 3.

  Since the configuration of the halogen lamp 2 is substantially the same as that in the first embodiment, a detailed description is omitted here.

  The casing 3 is a member that houses the halogen lamp 2 therein, and is formed in a tubular shape. One end of the halogen lamp 2 is fixed to one end 3a of the cylindrical casing 3, and the other end of the halogen lamp 2 is fixed to the other end 3b of the cylindrical casing 3. The central portion of the halogen lamp 2 excluding one end and the other end constitutes the irradiation unit 21. In addition, a predetermined interval is provided between the inner peripheral surface of the casing 3 and the surface of the irradiation unit 21 of the halogen lamp 2, and the irradiation unit 21 is configured so as not to contact the inner peripheral surface of the casing 3. ing. The power supply wiring and the control wiring connected to the halogen lamp 2 have a structure that is drawn out through the outer casing 6.

  This casing 3 is formed from a fluororesin. Examples of the fluorine-based resin include polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkylvinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ethylene-tetrafluoroethylene Copolymer (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), tetrafluoroethylene-hexafluoropropylene-perfluoroalkylvinyl ether copolymer (EPE), and the like can be given. In the present embodiment, the casing 3 is formed by using, among the above-mentioned fluorine-based resin materials, particularly tetralithoethylene (PTFE; melting point: 330 ° C.) having high heat resistance.

  As shown in FIGS. 3 and 4, the casing 3 according to the second embodiment is arranged in a state where the tubular portion has a space 4 formed between the inner pipes 32. The outer tube 33 is provided with a double tube structure. Both the inner tube 32 and the outer tube 33 are formed in a circular shape in cross section. Since the space 4 formed between the inner tube 32 and the outer tube 33 is formed as a closed space, one end of the inner tube 32 and one end of the outer tube 33 are connected to each other. Similarly, the other end of the inner tube 32 and the other end of the outer tube 33 are connected to each other. At one end 3a of the casing 3, an inlet 35 through which a liquid (fluid to be heated) can flow into the space 4 is provided, and at the other end 3b, the inner pipe 32 and the An outlet 36 from which the liquid (the fluid to be heated) flowing into the space 4 between the outer tubes 33 can flow out is provided. In addition, the inner tube 32 formed of the fluororesin constitutes the transmission part 31 in the casing 3.

  The outer casing 6 is a rectangular parallelepiped casing having an internal space, as shown in FIGS. Inside the outer casing 6, the casing 3 containing the halogen lamp 2 is arranged. The material constituting the outer casing 6 is not particularly limited, but is preferably formed of a fluorine-based resin as in the case 3 described above. A through hole 61 for an inlet and a through hole 62 for an outlet are formed in the ceiling of the outer casing 6, and a liquid supply pipe 71 connected to the inlet 35 of the casing 3 via the through hole 61 for the inlet. And a liquid discharge pipe 72 connected to the outlet 36 of the casing 3 via an outlet through-hole 62. A wiring through-hole 63 is also formed in the ceiling of the outer casing 6, and a power supply wiring and a control wiring connected to the halogen lamp 2, and a wiring of a temperature sensor disposed on the surface of the casing 3 and the like. And the like are drawn out of the outer casing 6.

  Here, as shown in FIG. 5, which is a schematic configuration sectional view showing a DD section of FIG. 3, the liquid supply pipe 71 is disposed so as to be perpendicular to the ceiling of the outer casing 6. Similarly, the liquid discharge pipe 72 is also arranged to be perpendicular to the ceiling of the outer casing 6. In addition, the inlet 35 in the casing 3 to which the liquid supply pipe 71 is connected and the outlet 36 in the casing 3 to which the liquid discharge pipe 72 is connected are on the same axis along the longitudinal direction of the casing 3 (in FIG. 5, (On the same axis perpendicular to the plane of the drawing).

  In the light heating type heater 1 having such a configuration, the liquid to be heated (the fluid to be heated) supplied through the liquid supply pipe 71 is connected to the inner pipe 32 and the outer pipe via the inlet 35 in the casing 3. It is supplied to the space 4 between the pipe 33. The liquid (the fluid to be heated) guided to the inlet 35 passes through the space 4 toward the outlet 36, and is heated by the light emitted from the halogen lamp 2 at this time. The light emitted from the halogen lamp 2 transmits through the inner tube 32 (transmitting portion 31) made of a fluorine-based resin without being absorbed, and directly heats the liquid (the fluid to be heated) passing through the space portion 4. . The liquid (fluid to be heated) heated by the halogen lamp 2 is guided to the liquid discharge pipe 72 via the outlet 36 of the casing 3 and supplied to the outside of the light heater 1. Since the casing 3 is formed of a fluorine-based resin material, its heat-resistant temperature is about 200 ° C. to 300 ° C., while the surface temperature of the halogen lamp 2 is, for example, about 600 ° C. to 800 ° C. Although the temperature will be reached, the liquid flowing in contact with the surface of the inner tube 32 while the liquid (the fluid to be heated) passes through the space 4 formed between the inner tube 32 and the outer tube 33 Since the (heated fluid) strongly removes the heat of the inner tube 32 (outer tube 33), a situation occurs in which the temperature of the casing 3 (inner tube 32 and outer tube 33) exceeds the heat-resistant temperature and melts. Nothing to do.

  The light heating type heater 1 according to the second embodiment of the present invention directly heats a liquid (fluid to be heated) by the light emitted from the halogen lamp 2 as described above, and thus has a high heating efficiency. -Since the casing 3 is made of a fluorine-based resin while having a heating ability, the casing 3 is not corroded by a liquid such as hydrofluoric acid, phosphoric acid, or a strong alkali, and these liquids are used. It becomes possible to heat.

  As shown in FIG. 5, the inlet 35 in the casing 3 to which the liquid supply pipe 71 is connected and the outlet 36 in the casing 3 to which the liquid discharge pipe 72 is connected are the same along the longitudinal direction of the casing 3. When the liquid is not provided on the axis, the mixing effect of the liquid (fluid to be heated) flowing from the inlet 35 in the space 4 is enhanced, and the light irradiation from the halogen lamp 2 makes it more efficient. In addition, the liquid (the fluid to be heated) can be uniformly heated.

  As described above, the light heating type heater 1 according to the second embodiment of the present invention has been described, but the specific configuration of the light heating type heater 1 is not limited to the above embodiment. For example, as shown in the schematic cross-sectional view of FIG. 6 and the schematic cross-sectional view of the EE cross-section shown in FIG. 7, quartz disposed between the inner tube 32 of the casing 3 and the halogen lamp 2. You may comprise so that the pipe | tube 5 may be provided. The quartz tube 5 is a tubular body having excellent light transmittance and heat resistance, and is disposed at least at a position (opposing position) corresponding to the cylindrical portion (irradiation portion 21) of the halogen lamp 2. In addition, it is preferable that the quartz tube 5 is arranged at least in close contact with the inner tube 32 (the transmission part 31) in the casing 3.

  Here, since the casing 3 of the light heating type heater 1 according to the second embodiment is formed of a fluorine-based resin material, as the temperature increases, the casing 3 is softened and easily deformed. In such a state, a part of the inner tube 32 of the casing 3 may be deformed and approach the halogen lamp 2 due to the liquid pressure of the liquid (fluid to be heated) flowing between the inner tube 32 and the outer tube 33. If the deformation of the inner tube 32 becomes large and the deformed portion of the inner tube 32 comes into contact with the surface of the irradiation part 21 of the halogen lamp 2, there is a possibility that the inner tube 32 may be broken or otherwise damaged. However, by disposing the quartz tube 5 between the inner surface of the inner tube 32 and the irradiation part 21 of the halogen lamp 2, deformation such that a part of the inner tube 32 approaches the irradiation part 21 of the halogen lamp 2 occurs. Even if it does, the quartz tube 5 functions as a stopper that supports the inner tube 32 and suppresses its deformation, and the deformed portion of the inner tube 32 comes into contact with the surface of the irradiation unit 21 of the halogen lamp 2. It is possible to effectively prevent such a situation from occurring, and prevent the inner tube 32 (casing 3) from being damaged or damaged.

  In particular, when a configuration is adopted in which the quartz tube 5 is arranged closely to the inner tube 32 (transmission part 31) in the casing 3, it is possible to prevent the deformation itself due to the softening of the casing 3. Become.

  As shown in the schematic cross-sectional view of FIG. 8, a wall portion 37 connecting the inner tube 32 and the outer tube 33 is provided in the space portion 4, and the wall portion 37 is provided on the surface of the inner tube 32. It may be arranged so as to be wound in a spiral shape, and a spiral flow path 38 extending from the inlet 35 to the outlet 36 may be defined by the wall 37. When such a configuration is adopted, the liquid (fluid to be heated) flowing from the inlet 35 of the casing 3 flows around the elongated irradiation unit 21 of the halogen lamp 2 along the longitudinal direction of the irradiation unit 21. The liquid (heated fluid) absorbs from the halogen lamp 2 because the liquid (heated fluid) absorbs the liquid (heated fluid) from the halogen lamp 2 because it is guided to the outlet 36 while spirally rotating. And the liquid (the fluid to be heated) can be more efficiently heated.

  In addition, the light heating type heater 1 according to the second embodiment is configured to include the outer casing 6, but such an outer casing 6 is omitted, and the light heating type heater 1 is configured as an internal passage heating type heater. May be.

  Further, in the light heater 1 according to the second embodiment, the outer casing may be configured to be covered with a metal sheet such as an aluminum foil or a gold foil. By performing such coating of the metal sheet, the heating efficiency with respect to the liquid (the fluid to be heated) can be further improved. Further, about 10% to 20% of the light emitted from the halogen lamp passes through the outer casing and escapes to the outside. However, by covering the metal sheet, the worker is exposed to glare caused by the light transmitted through the outer casing. The eyes can be protected.

DESCRIPTION OF SYMBOLS 1 Light heating type heater 2 Halogen lamp 21 Irradiation part 3 Casing 3a One end side of casing 3b The other end side of casing 31 Transmissive part 32 Inner pipe 33 Outer pipe 34 Space 35 Inlet 36 Outlet 37 Wall 38 Spiral flow Road 4 Space portion 5 Quartz tube 6 Outer casing 61 Inlet through hole 62 Outlet through hole 63 Wiring through hole 71 Liquid supply pipe 72 Liquid discharge pipe

Claims (9)

A light heating type heater including a halogen lamp and a casing that hermetically surrounds the halogen lamp,
The casing includes a transmission unit that transmits light of the halogen lamp to the outside,
The light-transmitting heater is characterized in that the transmission section is formed of a fluorine resin.   The heater according to claim 1, wherein the fluorine-based resin is polytetrafluoroethylene (PTFE).   The light heating type heater according to claim 1, further comprising a quartz tube disposed between the casing and the halogen lamp.   The light heating type heater according to claim 3, wherein the quartz tube is disposed in close contact with the transmission portion in the casing. A light heating type heater including a halogen lamp and a cylindrical casing that houses the halogen lamp therein,
The casing has a double pipe structure including an inner pipe and an outer pipe arranged in a state where a space is formed between the inner pipe and the casing,
On one end side of the casing, an inlet portion through which a heated fluid can flow into the space portion is provided, and on the other end side, a heated fluid flowing into the space portion via the inlet portion is provided. There is an outlet part that can flow out,
The inner tube and the outer tube are formed of a fluorine-based resin.   The heater according to claim 5, wherein the fluorine-based resin is polytetrafluoroethylene (PTFE).   7. The heater according to claim 5, further comprising a quartz tube disposed between the inner tube and the halogen lamp.   The light heating type heater according to claim 7, wherein the quartz tube is arranged closely to the inner tube. A wall portion connecting between the inner tube and the outer tube,
9. The wall according to claim 5, wherein the wall is arranged to spirally wind the surface of the inner tube, and defines a spiral flow path extending from the inlet to the outlet. 10. The light heating type heater according to any one of the above.

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