JP5004001B2 - Superheated steam generator - Google Patents

Description

  The present invention relates to a superheated steam generator for generating superheated steam.

In recent years, a superheated steam generator that heats water vapor to a high temperature of 100 ° C. or higher to generate a colorless and transparent gas (H ₂ O gas) has been provided. This superheated steam is used for various purposes such as a deodorizing device, a cooking device, a carbonizing device, and a sterilizing device. Such a superheated steam production | generation apparatus is disclosed by the following patent documents 1 thru | or 3, for example.

JP 2004-251605 A JP 2004-233040 A JP-A-8-193704

The superheated steam generator disclosed in Patent Documents 1 and 2 is an electromagnetic induction superheat (IH:
Induction Heating is a device that superheats water vapor by allowing high-frequency alternating current to flow through the coil while allowing water vapor to pass through the tube around which the coil is wound. Conventionally, such an electromagnetic induction superheated superheated steam generator has been mainstream.

  On the other hand, the superheated steam generation apparatus disclosed in Patent Document 3 is an apparatus that uses an electric heater instead of a coil as the superheating means. In this superheated steam generator, an electric heater is installed in a sealed casing through which a plurality of thin tubes through which water vapor passes, and a heat conduction medium such as silicon oil is filled in the casing, and convection of the heat conduction medium is performed. A configuration is adopted in which the heat energy from the electric heater is transferred to the water vapor in the narrow tube for heating.

  However, since the superheated steam generators of Patent Documents 1 and 2 are of the electromagnetic induction heating type, it is necessary to wind an exciting coil around the tube, which is unsuitable for reducing the size and weight of the device. Moreover, since the superheated steam production | generation apparatus of the said patent document 3 heated water vapor | steam by the convection of a heat conductive medium, there existed a problem that heat conduction efficiency was not good.

  The present invention has been made to solve such problems, and an object of the present invention is to provide a superheated steam generator that is suitable for miniaturization and weight reduction and has high heat conduction efficiency.

In order to solve the above problems, the superheated steam generator according to the present invention is a superheated steam generator that generates superheated steam by heating the steam passing through the flow path, and has a cylindrical shape that holds the flow path inside. A flow path member, a heating means that is disposed inside the cylindrical flow path member, and that heats the cylindrical flow path member from the inner side mainly by radiation , while contacting the cylindrical circumferential surface of the cylindrical flow path member And a cylindrical heat insulating heat insulating material arranged to cover the cylindrical flow path member .

  According to the superheated steam generator according to the present invention, it is possible to provide a superheated steam generator suitable for reduction in size and weight and having high heat conduction efficiency.

  Hereinafter, the first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of the superheated steam generator 1 according to the first embodiment. 2 is a cross-sectional view taken along line AA in FIG. As shown in FIGS. 1 and 2, the superheated steam generator 1 includes a halogen heater 10, a double pipe 20, a heat insulating material 30, a temperature sensor 41, and a control circuit 42.

  The halogen heater 10 is a heating means for heating the vapor, and is driven by applying a voltage by the drive circuit 11. In this embodiment, a 4 kW cylindrical halogen heater is used, and its coil temperature rises to about 2200 ° C.

The double pipe 20 is made of stainless steel (SUS: Stainless steel) arranged coaxially.
Used Steel) includes an inner tube 22 and an outer tube 21. Steam to be heated passes through a cylindrical space surrounded by the inner tube 22 and the outer tube 21. That is, the cylindrical double tube 20 forms a cylindrical flow path member that forms a flow path through which the steam to be heated passes. For this reason, as shown in FIG. 1, a steam inlet 25 is provided at one end of the double pipe 20, and a steam outlet 26 is provided at the other end. For example, steam generated by a boiler or the like is introduced into the steam inlet 25, and superheated steam is obtained from the steam outlet portion 26.

  In the present embodiment, the inner tube 22 has a diameter of 100 mm, and the outer tube 21 has a diameter of 140 mm. Further, the inner outer surface of the double tube 20, that is, the inner surface of the inner tube 22 facing the halogen heater 10 is subjected to oxidation treatment. When the oxidation treatment is performed, the surface becomes dark, so that the reflectance can be suppressed and the radiation rate can be increased, and the heat transfer efficiency can be improved. Other than oxidation treatment, other treatments that can increase the emissivity, such as roughening the surface such as corroding with acid (roughening treatment) or blackening treatment (blackening treatment) ( The same effect can be obtained even if high emissivity treatment is performed.

  In the present embodiment, a baffle (baffle plate) 27 that is a spiral protrusion is integrally provided inside the outer tube 21. FIG. 3 is a cross-sectional view of the outer tube 21 for explaining the baffle 27. The steam flowing in the cylindrical gap space from the steam inlet portion 25 toward the steam outlet portion 26 is agitated while proceeding spirally along the baffle 27, so that the flow path distance becomes longer and the heat transfer efficiency is improved. Can be improved.

  The baffle 27 may be provided on the outer surface of the inner tube 22. When it is provided in the inner tube 22, it greatly contributes as a fin that enhances heat transfer efficiency. Further, baffles may be provided on both the inner side of the outer tube 21 and the outer side of the inner tube 22. At this time, preferably, if a projection mainly functioning as a fin is provided on the outer surface of the inner tube 22 and a projection mainly functioning as a baffle is provided on the inner surface of the outer tube 21, the heat transfer efficiency can be greatly improved. it can. Of course, the shape of the baffle is not limited to the spiral protrusion, and any other shape may be adopted as long as it is a shape capable of stirring the steam passing through the cylindrical gap between the inner tube 22 and the outer tube 21. Can do. Further, the shape of the fin may be freely set as long as the surface area can be increased.

  The heat insulating and heat insulating material 30 has a cylindrical shape and is disposed so as to cover the outer surface of the outer tube 21, that is, the surface of the double tube 20, and the heat energy from the halogen heater 10 is moved out of the superheated steam generator 1. This prevents the outflow and contributes to the improvement of heat transfer efficiency. Moreover, the heat insulation heat insulating material 30 is holding the halogen heater 10 so that the halogen heater 10 may be located in the central axis of the cylinder. Moreover, these insertion holes are provided at locations where the steam outlets 25 and 26 of the heat insulating and heat insulating material 30 are located, and the steam inlets 25 and 26 can be connected to an external pipe. Further, the periphery of the heat insulating and heat insulating material 30 is covered with a casing 31.

  The temperature sensor 41 is provided at the steam outlet 26 and measures the temperature of the superheated steam that is superheated to 100 ° C. or more and discharged from the steam outlet 26. The output of the temperature sensor 41 is sent to the control circuit 42 and is used by the control circuit 42 to control the heating amount of the halogen heater 10. For example, when the temperature of the generated superheated steam is desired to be 300 ° C., the control circuit 42 may perform feedback control of the drive circuit 11 of the halogen heater 10 by PID control based on the output of the temperature sensor 41.

  As mentioned above, although the structure of the superheated steam generation apparatus 1 which concerns on this embodiment was demonstrated, the operation | movement at the time of producing | generating superheated steam with the superheated steam generation apparatus 1 is demonstrated.

  First, the halogen heater 10 is driven by the drive circuit 11, and in this embodiment, the temperature is raised to 2200 ° C. The thermal energy released by the halogen heater 10 is transferred to the inner tube 22 mainly as radiant heat by radiation, and heats the inner tube 22 to about 400 ° C. The thermal energy transferred to the inner tube 22 is further transmitted to the outer tube 21 as radiant heat to heat the outer tube 21.

  On the other hand, the steam generated by the boiler or the like and flowing into the cylindrical gap (flow path) surrounded by the outer pipe 21 and the inner pipe 22 from the steam inlet section 25 is spirally swirled by the baffle 27 while being steam spirally. Proceed to 26. At this time, the steam is heated to 300 ° C. by the radiant heat emitted from the heated inner tube 22 and outer tube 21, and is discharged from the steam outlet 26 as superheated steam. Of course, the contribution is small compared to radiation, but heat transfer is also performed by convection of steam and conduction when the steam contacts the inner tube 22 and the outer tube 21.

  The superheated steam heated to 300 ° C. mainly by radiant heat is discharged from the steam outlet 26, and the temperature of the superheated steam at the time of discharge is measured by the temperature sensor 41. The measured temperature is sent to the control circuit 42, and the control circuit 42 performs PID control of the drive circuit 11 of the halogen heater 10 so as to approach the set temperature (300 ° C.) that is the target value. As a result, superheated steam heated to a predetermined temperature is generated.

  In addition, as a utilization form of the superheated steam produced | generated by a superheated steam production | generation apparatus, it utilizes for various uses, such as a deodorizing apparatus, a cooking device, a carbonization apparatus, and a sterilization apparatus. The temperature of superheated steam required for each application differs, but for example, when applied to a carbonization device, an object can be carbonized at 350 ° C or higher, so that superheated steam at 350 ° C or higher is generated. There is a need.

  As described above, the present embodiment has been described in detail. According to the present embodiment, the steam to be heated is passed through a cylindrical gap that is a flow path sandwiched between the outer tube and the inner tube, and is disposed inside the inner tube. The heating means (halogen heater) is configured to heat the inner tube mainly by radiation, so that the steam is heated. Therefore, the heat energy of the heating means is used to efficiently heat the steam and is transmitted. Thermal efficiency can be greatly increased.

  Further, since the superheated steam generator according to the present embodiment has a configuration in which the superheater is disposed inside the double pipe, a heat transfer medium is unnecessary, the structure is simple, the apparatus is miniaturized and lightweight. It is possible to Moreover, according to the present embodiment, the radiation can be used uniformly and efficiently by providing the flow path through which the steam passes around the heating means. Further, since the energy source is radiation, high temperature heating is possible in a short time, and high temperature superheated steam can be obtained. In addition, when heated, no by-product is generated, and this is a clean superheated steam generator.

  Subsequently, Modification 1 of the present embodiment will be described. In the above-described embodiment, a single halogen heater is provided. In the first modification, a case where there are a plurality of halogen heaters will be described.

  FIG. 4 shows a modification in the case where there are a plurality of halogen heaters. 4A is a cross-sectional view of the superheated steam generator when there are two halogen heaters, and FIG. 4B is a cross-sectional view of the superheated steam generator when there are four halogen heaters.

  As shown in FIG. 4A, when there are two halogen heaters, the cross section has an oval shape (track shape) so that the heat energy from the halogen heater 10 is transmitted to the inner surface of the double tube 20 as uniformly as possible. ) Is used. Further, as shown in FIG. 4B, in the case where there are four halogen heaters 10, the double tube 20 remains circular in shape so that the heat energy is equally transmitted, and the axis of each halogen heater 10 is Are arranged so as to be concentrically arranged at an equal angle.

  Then, the modification 2 of this embodiment is demonstrated. Fig.5 (a) shows sectional drawing of the outer tube | pipe which concerns on the modification 2 of 1st Embodiment, FIG.5 (b) is sectional drawing in the BB line of Fig.5 (a). In the second modification, not a spiral baffle but semi-annular baffles 27 are formed at two locations inside the outer tube 21.

  As shown in FIG. 5, the baffles 27 provided on the steam inlet portion 25 side and the steam outlet portion 26 side inside the outer tube 21 are formed at positions shifted from each other by 180 degrees. Therefore, the steam that flows in from the steam inlet portion 25 and proceeds toward the steam outlet portion 26 on the right side in the drawing is directed downward by the baffle 27 on the inlet side and is moved upward by the baffle 27 on the outlet side in the drawing. The steam flowing in the cylindrical gap is diffused by receiving resistance and heat transfer efficiency can be improved.

  Instead of a semi-annular baffle, a 1/3 annular (120 degree) baffle may be provided. In this case, in order to diffuse the steam efficiently, it is only necessary to provide 1/3 annular baffles at three positions with a shift of 120 degrees when viewed in the axial direction of the outer tube 21. Further, baffles may be further provided at a plurality of locations. Of course, also in the case of this modification, a fin can be provided in the inner tube 22 or the like as appropriate.

  Next, a second embodiment according to the present invention will be described. FIG. 6 is a cross-sectional view of the superheated steam generator 1 according to this embodiment. In the first embodiment, the flow path of the steam to be heated is a cylindrical gap formed by the outer tube 21 and the inner tube 21, but in this embodiment, a cylindrical coil in which a stainless steel thin tube is wound in a coil shape. The pipe 23 is characterized in that a flow path for the steam to be heated is formed. That is, in the first embodiment, the double pipe 20 forms a cylindrical flow path member, whereas in the present embodiment, the cylindrical coil pipe forms a cylindrical flow path member. Since the other configuration is the same as that of the first embodiment, the same number is assigned to the same configuration, and the description is omitted.

  As shown in FIG. 6, the superheated steam generation device 1 according to the second embodiment is provided with a cylindrical coil tube 23 at the position of the inner tube of the first embodiment. As described above, in the cylindrical coil tube 23, the inside of the narrow tube is a flow path through which the steam to be heated passes, one end of the narrow tube is connected to the steam inlet 25, and the other end is the steam outlet. 26. A casing 31 is disposed around the heat insulating material 30 so as to cover the heat insulating material 30.

  In such a configuration, the steam flowing in from the steam inlet portion 25 advances toward the steam outlet portion 26 while spirally spiraling along the flow path inside the cylindrical coil tube 23. At this time, the halogen heater 10 disposed inside the cylindrical coil tube 23 mainly heats the inner surface of the cylindrical coil tube 23 by radiant heat. The steam passing through the narrow tube is heated by the radiant heat emitted from the narrow tube, and superheated steam is generated at the steam outlet 26.

  According to the present embodiment, the same effect as in the first embodiment can be obtained, and the flow path is elongated, so that high-pressure superheated steam can be obtained.

  As described above, the first and second embodiments of the present invention have been described in detail. However, the embodiments of the present invention are not limited to the above-described embodiments and modifications thereof, and do not depart from the spirit of the present invention. Various modifications are possible. For example, in the above embodiment, the cylindrical outer tube and the inner tube are employed, but other shapes such as a rectangular tube may be employed as appropriate.

  In the above embodiment, the halogen heater that can be heated to about 2200 ° C. is used as the heating means, but other heaters may be used. For example, other electric heaters such as a carbon heater can be used.

FIG. 1 is a cross-sectional view of the superheated steam generator according to the first embodiment. 2 is a cross-sectional view taken along line AA in FIG. FIG. 3 is a cross-sectional view of the outer tube according to the first embodiment. FIG. 4 is a cross-sectional view of the superheated steam generator according to Modification 1 of the first embodiment. FIG. 5 is a cross-sectional view of an outer tube according to Modification 2 of the first embodiment. FIG. 6 is a cross-sectional view of the superheated steam generator according to the second embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Superheated steam production | generation apparatus 10 Halogen heater 11 Drive circuit 20 Double pipe 21 Outer pipe 22 Inner pipe 25 Steam inlet part 26 Steam outlet part 27 Baffle 30 Thermal insulation heat insulating material 31 Casing 41 Temperature sensor 42 Control circuit

Claims (5)

A superheated steam generator that generates superheated steam by heating steam passing through a flow path,
A cylindrical channel member holding the channel inside;
A heating means disposed inside the cylindrical flow path member and heating the cylindrical flow path member from the inside mainly by radiation;
A cylindrical heat insulating and heat-insulating material arranged so as to cover the cylindrical flow path member while being in contact with the cylindrical peripheral surface of the cylindrical flow path member ;
An overheated steam generation device comprising:   The cylindrical flow path member includes an outer pipe and an inner pipe disposed inside the outer pipe, and the flow path is a cylindrical gap between the outer pipe and the inner pipe. The superheated steam generator according to claim 1.   The superheated steam generation device according to claim 1, wherein the cylindrical flow path member is a pipe wound in a coil shape, and the inside of the pipe forms the flow path.   The superheated steam generator according to any one of claims 1 to 3, wherein the heating means is a halogen heater.   The superheated steam generator according to claim 2, further comprising a protrusion on at least one of the inner side of the outer pipe and the outer side of the inner pipe.

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