JP5258852B2 - Electromagnetic induction heating device - Google Patents

Description

  The present invention relates to an electromagnetic induction heating apparatus that heats a material to be heated using electromagnetic induction.

In a conventional electromagnetic induction heating device, as in Non-Patent Document 1, for example, an iron core, a conductive heating tube wound spirally around the iron core, and an alternating current wound around the iron core are passed. In some cases, the heating tube is provided with a primary coil installed to cause a secondary induction current to flow by electromagnetic induction. In this heating device, when a secondary induction current flows in the heating tube, Joule heat based on the electric resistance of the heating tube is generated, and this heat is transmitted to the heated material flowing inside the heating tube, so that the heated material Can be heated.
This electromagnetic induction heating apparatus is often used in a state in which both ends of a heating pipe are connected to an external pipe such as a pipe of a material to be heated or a fence provided in an external apparatus such as a plant.

“Self-tube type nesco heater”, [online], Mitsubishi Rayon Engineering Co., Ltd. [searched on January 15, 2010], Internet <URL: http://www.mrc.co.jp/mre/plant/plant_03_05 .html>

By the way, it is common to use a metallic material because of the specifications such as the corrosion resistance of the heating tube against the substance to be heated. There are many. For this reason, in order to heat a to-be-heated material efficiently, it is necessary to flow a big electric current (for example, several thousand-several tens of thousands of amperes) to a heating tube as a secondary induction current.
However, when a large current is passed through the heating pipe, the possibility that the secondary induced current leaks to the external pipe increases. In addition, consideration must be given to ensuring the safety of workers so as not to get an electric shock due to the voltage (secondary induction voltage) applied to the heating tube depending on the length of the heating tube. As a result, the equipment becomes large and electromagnetic There exists a problem that the manufacturing cost of an induction heating apparatus and the external apparatus connected to this becomes high.

Furthermore, in order to manufacture an electromagnetic induction heating device at a lower cost, it is preferable to use a low frequency power source, which is a general commercial power source, as an input to the primary coil. In order to obtain a current, it is necessary to set a large turn ratio (transformation ratio) between the primary coil and the heating tube.
However, since the number of turns of the heating tube is set depending on the specifications of the external device to which the electromagnetic induction heating device is connected (for example, the reached temperature and flow velocity of the heated material flowing in the heating tube), the heated material is efficiently used. In order to increase the winding ratio (transformation ratio) between the primary coil and the heating tube so that the heating can be performed well, the number of turns of the primary coil must be set very large with respect to the number of turns of the heating tube. As a result, the volume of the primary coil becomes large, and there is a possibility that the design of the electromagnetic induction heating device becomes difficult.

  The present invention has been made in view of the above-described circumstances, and provides an electromagnetic induction heating device that can be manufactured at low cost while ensuring the safety of an operator and can be easily designed. Objective.

In order to solve the above problems and achieve such an object, an electromagnetic induction heating device according to the present invention includes an iron core, a spiral tube portion formed by spirally winding the iron core, and the A conductive heating tube having an inlet tube portion and an outlet tube portion connected to both ends of the spiral tube portion and extending radially outward of the spiral tube portion, and being wound around the iron core to supply an alternating current A primary coil that generates a secondary induction current in the spiral tube portion by electromagnetic induction, a case that houses the iron core, the heating tube, and the primary coil inside, and a purge gas that enters and exits between the inside and outside of the case A purge mechanism that is formed by winding the spiral tube portion in close contact with each other, and both end portions of the spiral tube portion are arranged at the same circumferential position so as to be arranged in the axial direction of the spiral tube portion. Are arranged at the same circumferential position. Each part of the spiral tube portion, is grounded is electrically connected to one another by being joined together by welding, the frequency of the alternating current supplied to the primary coil, and a 10Hz or 400Hz or less, serial secondary induction The current is 1000 amperes or more and less than 100,000 amperes, the secondary induction voltage applied to the heating tube by the electromagnetic induction is 1 V or more and 8 V or less, and the purge mechanism converts the purge gas introduced into the case into the case It is characterized by being configured to spray directly on the primary coil .
In addition, each part of a spiral tube part has shown the middle part of the spiral tube part located between the both ends of the spiral tube part arranged in the axial direction of a spiral tube part, and these. For example, when the number of turns of the spiral tube portion is one, each portion of the spiral tube portion shows only both end portions of the spiral tube portion. Further, when the number of turns of the spiral tube portion is plural, each portion of the spiral tube portion indicates both ends of the spiral tube portion and a midway portion of the spiral tube portion arranged between them.

In the electromagnetic induction heating device having the above configuration, when a secondary induction current flows through the helical tube portion of the heating tube, Joule heat is generated according to the electrical resistance of the helical tube portion, and the helical tube portion generates heat. And the to-be-heated substance can be heated because the heat of a spiral tube part is transmitted to the to-be-heated substance which flows through the inside of a spiral tube part.
And according to this electromagnetic induction heating device, in addition to being formed so that the inlet tube portion and the outlet tube portion are separated from the outside of the spiral tube portion, the spiral tube portion arranged at the same circumferential direction position of the spiral tube portion Since each of the above is at ground potential, the inlet pipe portion and the outlet pipe portion are also at ground potential. Therefore, the secondary induced current does not flow through the inlet tube portion and the outlet tube portion. That is, it is possible to reliably prevent the secondary induced current from leaking to the outside through the inlet tube portion and the outlet tube portion.

  In addition, the length of the electric path of the secondary induced current in the spiral tube portion is based on the same circumferential position because each portion of the spiral tube portion arranged at the same circumferential direction position of the spiral tube portion is grounded. It becomes the length of one round (one winding) of the spiral tube portion. For example, the electrical path of the secondary induced current in the spiral tube portion that is wound a plurality of times is equivalent to one in which the independent one-turn windings are electrically connected in parallel. Therefore, even if a large secondary induction current flows through a plurality of spiral tube portions, the secondary induction voltage applied to the spiral tube portion can be suppressed to a low voltage (for example, 8 V or less) that does not cause an electric shock.

In addition, since the electrical path of the secondary induced current in the spiral tube portion is equivalent to the length of one turn of the spiral tube portion regardless of the number of turns of the spiral tube portion, the turns ratio of the primary coil to the spiral tube portion ( (Transformation ratio) becomes equal to the number of turns of the primary coil. That is, even if the number of turns of the primary coil is set to be smaller than that in the conventional case, the turn ratio (transformation ratio) between the primary coil and the spiral tube portion can be easily set large.
From the above, even when a low-frequency power source is used as an input to the primary coil, a large secondary induction current can be passed through the heating tube to efficiently heat the material to be heated. Further, since the number of turns of the primary coil can be set to be small, the volume of the primary coil is reduced, and as a result, the electromagnetic induction heating device can be easily designed.
Furthermore, if only the Joule heat generated in the circumference of the spiral tube portion is known, the Joule heat generated in the entire spiral tube portion can be calculated simply by multiplying the Joule heat by the number of turns of the spiral tube portion. The design of the heating performance can also be easily performed.

Further, in the above electromagnetic induction heating system, wherein the respective portions of the spiral tube portion arranged in the same circumferential position, are electrically connected to each other, a plurality of at least one of each part of the spiral tube portion (e.g. helical tube the only one) of the ends of the parts, rather I by connecting the wiring for grounding, each portion of the spiral tube portion can be easily performed tasks to be grounded.

Incidentally, in the electromagnetic induction heating device, Rukoto the spiral tube portion is formed by winding in close contact, the round portion between the spiral tube portion adjacent to each other, means to close contact over its circumferential direction It is .

In this configuration, since the distance between the circumferential portions of the spiral tube portions is shortened, the thermal insulation effect that the circumferential portions of the adjacent spiral tube portions are mutually warmed is increased, so Joule heat generated in the spiral tube portions is reduced. It becomes difficult to escape from the outer surface of the spiral tube. As a result, the substance to be heated can be heated more efficiently.
Further, since the dimension of the spiral tube portion in the axial direction can be reduced compared to the case where the spiral tube portion is formed in a spiral shape with a gap, the size of the electromagnetic induction heating device can be reduced.
Furthermore, when an iron core extending in the axial direction of the spiral tube portion or the primary coil is provided, the length of the shaft portion of the iron core can be set small, so that magnetic and electrical losses are reduced, and the power of the electromagnetic induction heating device is reduced. The rate will improve.

Further , in the electromagnetic induction heating device, each part of the spiral pipe part adjacent in the axial direction is joined to each other by welding, so that a separate conductor such as a conductor for electrically connecting each part of the adjacent spiral pipe part is provided. Since a member becomes unnecessary, the number of components of the electromagnetic induction heating device can be reduced. In addition, since a separate member such as a conductive wire with low heat resistance is not required, it is possible to reliably prevent the electrical reliability of the heating tube from being lowered due to, for example, disconnection of the conductive wire due to Joule heat generated in the heating tube. . Furthermore, since the number of steps for manufacturing the electromagnetic induction heating device is reduced as the number of component parts decreases, it can be efficiently manufactured, and as a result, the manufacturing cost can be further reduced.

Furthermore, the EMIH device, Ri 400Hz or less der frequency 10Hz or more of the alternating current supplied to the primary coil, the alternating current of the frequency range, and outputs the low-frequency power source, which is a general commercial power source Therefore, the electromagnetic induction heating device can be manufactured at a lower cost by using a low frequency power source.

Further , in the electromagnetic induction heating device , a purge gas such as clean air or nitrogen is allowed to enter and exit between the inside and the outside of the case by a purge mechanism, so that foreign substances such as dangerous gas, moisture, and dust enter the case from the outside. Intrusion can be prevented. Moreover, the temperature rise in a case based on the heat_generation | fever of a primary coil or a heating tube by an alternating current or a secondary induction current can be suppressed or prevented.
In particular, the primary coil can be efficiently cooled by directly blowing the purge gas introduced into the case onto the primary coil. For this reason, even if a primary coil heat | fever-generates by sending an alternating current through a primary coil, the temperature rise of a primary coil can be suppressed. In addition, it is possible to prevent the deterioration of insulation accompanying the temperature rise of the primary coil.

The electromagnetic induction heating device includes a case that houses the iron core, the heating tube, and the primary coil therein, a purge mechanism that allows purge gas to enter and exit between the inside and the outside of the case, and the purge gas. A pressure adjusting valve for holding the pressure inside the case at a predetermined pressure, and a temperature sensor for measuring the temperature of the heating pipe, provided in a discharge pipe portion of the purge mechanism for discharging the air inside the case to the outside And a power supply control unit that stops supply of the alternating current to the primary coil based on the measurement result when the measurement result of the temperature sensor is equal to or higher than a predetermined temperature.

The predetermined pressure indicates, for example, a pressure value of the case or a pressure value equal to or lower than the pressure value. Further, the value of the predetermined pressure can be set by operating the pressure adjusting valve in accordance with the flow rate of the purge gas introduced into the case. The predetermined temperature indicates a combustible gas such as hydrogen or a combustible liquid vapor such as gasoline.
In this configuration, the internal pressure of the case can be prevented from becoming excessively high while preventing foreign substances such as hazardous gas, moisture, and dust from entering the case from the outside by the pressure adjusting valve.
Also, by stopping the supply of alternating current to the primary coil when the temperature of the heating tube exceeds a predetermined temperature, for example, the temperature of the heating tube suddenly rises suddenly, and such a temperature rise As a result, the internal pressure of the case suddenly increases, and even if this increase cannot be suppressed by the pressure adjustment valve, the AC current is stopped and the pressure supply device is stopped (the supply valve is closed or the blower is It is possible to reliably prevent the internal pressure of the case from becoming excessively high.

Further, in the electromagnetic induction heating device, heat insulation that covers the entire heating tube and prevents the Joule heat generated in the spiral tube portion and the heat of the heated material flowing inside the heating tube from escaping to the outside of the heating tube. It is preferable that a material is provided and the primary coil is arranged outside the heat insulating material.

According to the present invention, since each part of the spiral tube portion arranged at the same circumferential position where both ends of the spiral tube portion are located is grounded, the electrical safety of the operator is ensured while the electromagnetic safety is ensured. The manufacturing cost of the induction heating device and the external device connected to the induction heating device can be kept low.
Furthermore, since the structure for efficiently heating the material to be heated can be realized with a small number of turns of the primary coil, the electromagnetic induction heating device can be easily designed.

1 is a schematic cross-sectional view showing an electromagnetic induction heating device according to an embodiment of the present invention. It is AA arrow sectional drawing of FIG. It is BB arrow sectional drawing of FIG. It is a schematic diagram which shows simply the grounding state of the helical tube part with which the electromagnetic induction heating apparatus of FIGS. 1-3 is equipped.

Hereinafter, an embodiment of an electromagnetic induction heating device according to the present invention will be described with reference to FIGS. 1 to 4.
As shown in FIGS. 1-3, the electromagnetic induction heating apparatus 1 of this embodiment is connected to external devices, such as a plant which handles a to-be-heated material, and heats to-be-heated material using electromagnetic induction, A case 2 and an electromagnetic induction heating unit 3 arranged in the case 2 are generally configured.

The case 2 plays a role of accommodating the electromagnetic induction heating unit 3 and protecting it from the environment outside the case 2. The case 2 is formed of a metal material such as a general structural rolled steel material, and by grounding the case 2, the magnetic flux and current generated in the electromagnetic induction heating unit 3 based on the electromagnetic induction are shielded. These magnetic fluxes and currents are prevented from leaking outside the case 2.
The case 2 also has a function of allowing clean air and nitrogen to enter and exit between the outside and the inside, and this function can suppress or prevent a temperature rise in the space in the case 2. The case 2 also has a function of preventing entry of foreign matter from the outside to the inside so that foreign matters such as moisture and dust do not adversely affect the electromagnetic induction heating unit 3.

Further, the case 2 is provided with a purge mechanism 22 that allows purge gas such as clean air and nitrogen to enter and exit between the outside and the inside. The purge mechanism 22 includes an introduction pipe portion 23 for introducing purge gas into the inside from the outside of the case 2 and a discharge pipe portion 24 for discharging the purge gas and other air remaining inside the case 2 to the outside. Yes. Both the introduction pipe part 23 and the discharge pipe part 24 are constituted by pipes, ducts, and the like.
The introduction pipe portion 23 extends from the side wall portion of the case 2 to the central portion inside the case 2. In this configuration, the purge gas introduced into the case 2 is directly blown onto the primary coil 5 of the electromagnetic induction heating unit 3 disposed in the central portion inside the case 2. On the other hand, the discharge pipe portion 24 is provided with a pressure adjustment valve 25 for keeping the pressure inside the case 2 at a predetermined pressure. Here, the predetermined pressure indicates, for example, a pressure value of the case 2 or a pressure value equal to or lower than the pressure value. Further, the value of the predetermined pressure can be set by operating the pressure adjustment valve 25 in accordance with the flow rate of the purge gas introduced into the case 2.

The electromagnetic induction heating unit 3 includes an iron core 4, a primary coil 5, and a heating tube 6.
The iron core 4 is approximately 8 by a rod-shaped shaft portion 41 inserted through a primary coil 5 and a heating tube 6 described later, and a frame body portion 42 formed in a rectangular ring shape so as to connect both ends of the shaft portion 41 in the longitudinal direction. A closed magnetic circuit for magnetic flux generated by electromagnetic induction is defined. Note that the frame body portion 42 is formed so as to surround the primary coil 5 and the outside of the heating tube 6.
The iron core 4 configured as described above is fixed to the upper surface 7 a of the conductive base plate 7 placed on the placement surface 2 a in the case 2. The base plate 7 has conductivity and is grounded similarly to the case 2.

The primary coil 5 is attached by being wound around the shaft portion 41 of the iron core 4, and is disposed in the central portion inside the case 2. Both ends of the primary coil 5 are drawn out of the case 2 from a terminal box 21 formed on the side of the case 2 and then connected to an AC power source (not shown) such as a low frequency power source. When the primary coil 5 is connected to a low frequency power source, the frequency of the alternating current supplied to the primary coil 5 is, for example, 10 Hz or more and 400 Hz or less.
The heating tube 6 has conductivity, and is connected to a spiral tube portion 61 formed by winding a plurality of spirals on the outer side of the primary coil 5 and both longitudinal ends 64A and 64B of the spiral tube portion 61, respectively. The inlet pipe 62 and the outlet pipe 63 are provided.
The spiral tube portion 61 is formed by being wound in a close contact state. In other words, the circumferential portions of the spiral tube portions 61 adjacent in the direction of the axis L1 of the spiral tube portion 61 are in close contact with each other in the circumferential direction. Further, both end portions 64A and 64B of the spiral tube portion 61 are arranged at the same circumferential position P1 of the spiral tube portion 61 so as to be arranged in the direction of the axis L1 of the spiral tube portion 61.

Then, both end portions 64A and 64B of the spiral tube portion 61 arranged at the same circumferential position P1 and the midway portion 64C (the respective portions 64 of the spiral tube portion 61) positioned between them are welded to each other. It is electrically connected by being joined. Note that, in portions other than the same circumferential position P1, the circumferential portions of the spiral tube portions 61 adjacent in the direction of the axis L1 of the spiral tube portion 61 may or may not be electrically connected to each other.
Furthermore, both end portions 64A and 64B and midway portion 64C of the helical tube portion 61 arranged at the same circumferential position P1 are grounded to the base plate 7 by a conducting wire (not shown) or a support 10 described later. The conducting wire may be connected to one or both of the both end portions 64A and 64B of the spiral tube portion 61, for example, connected to one or a plurality of locations in the midway portion 64C of the spiral tube portion 61. Also good.

  The inlet tube portion 62 and the outlet tube portion 63 are formed so as to extend radially outward from both end portions 64A and 64B of the spiral tube portion 61, respectively. In addition, although both ends 64A and 64B of the spiral tube portion 61 are opened in opposite directions, the inlet tube portion 62 and the outlet tube portion 63 connected thereto are bent in the middle portion thereof. The case 2 extends from the same side wall portion of the case 2 to the outside of the case 2 in a parallel state.

Furthermore, the electromagnetic induction heating unit 3 includes a temperature sensor 8 that measures the temperature of the heating tube 6 and a heat insulating material 9 that covers the entire heating tube 6 in addition to the above-described configuration.
The temperature sensor 8 includes a total of four of an inlet pipe part 62, an outlet pipe part 63, the vicinity of the end part 64B of the spiral pipe part 61 located on the outlet pipe part 63 side, and one of the midway parts 64C of the spiral pipe part 61. It is attached to the place. The temperature sensor 8 attached to the spiral tube portion 61 is arranged at the same circumferential direction position P1 of the spiral tube portion 61 or in the vicinity thereof.

The wires of the plurality of temperature sensors 8 are drawn from the terminal box 21 of the case 2 to the outside of the case 2 and then a power control unit (not shown) that controls the magnitude of the AC current supplied from the AC power source to the primary coil 5. )It is connected to the.
The power supply control unit plays a role of controlling the magnitude of the alternating current supplied to the primary coil 5 based on the measurement result of the temperature sensor 8 so that the substance to be heated in the outlet pipe unit 63 has a desired temperature. The power supply control unit also has a function of stopping the supply of the alternating current to the primary coil 5 based on the measurement result when the measurement result of the temperature sensor 8 is equal to or higher than a predetermined temperature. The predetermined temperature indicates, for example, 80% of the ignition temperature of the heated material or the dielectric breakdown temperature of the primary coil 5.

  The heat insulating material 9 is made of glass fiber, ceramic material, or the like, and plays a role of not releasing the Joule heat generated in the spiral tube portion 61 and the heat of the heated material flowing inside the heating tube 6 to the outside of the heating tube 6, It plays the role which does not give excessively the influence of the heat which arises in the heating tube 6 with respect to the iron core 4, the primary coil 5, etc. In addition, since the primary coil 5 and the shaft portion 41 of the iron core 4 are arranged inside the spiral tube portion 61, a portion of the heat insulating material 9 that covers the spiral tube portion 61 is a cylindrical shape that follows the shape of the spiral tube portion 61. Is formed.

In addition, the electromagnetic induction heating device 1 includes a plurality of (three in the illustrated example) supports 10 that support the heating tube 6 in a state of being spaced from the upper surface 7 a of the base plate 7. Each support body 10 has conductivity, and is formed integrally with a rod-like leg portion 11 standing on the upper surface 7 a of the base plate 7 and the upper end of the leg portion 11, and is arranged in the circumferential direction of the spiral tube portion 61. It is comprised by the storage frame part 12 which accommodates a part.
In the housing frame portion 12, a vertically long insertion hole 13 extending in the longitudinal direction of the leg portion 11 (in the direction of the axis L <b> 1 of the spiral tube portion 61) is formed, and the spiral tube portion 61 is inserted through the insertion hole 13. The longitudinal dimension of the insertion hole 13 is set to be equal to or slightly larger than the dimension of the spiral tube portion 61 in the direction of the axis L1. Further, the width dimension of the insertion hole 13 is set to be equal to or slightly larger than the outer diameter dimension of the tube portion of the spiral tube portion 61. Furthermore, the upper end of the insertion hole 13 can be opened and closed, and the ring-shaped spiral tube portion 61 can be easily inserted and removed from the upper end of the insertion hole 13.
The support 10 having the above-described configuration can be formed by appropriately combining rod-shaped members such as L-shaped angles made of a conductive material such as iron or stainless steel.

The plurality of supports 10 are arranged at equal intervals in the circumferential direction of the spiral tube portion 61.
One of the plurality of supports 10 (one support 10A) is in direct contact so as to be electrically connected to the spiral tube 61 at the same circumferential position P1 of the spiral tube 61, and The base plate 7 is also electrically connected. That is, both end portions 64A and 64B and midway portion 64C of the spiral tube portion 61 disposed at the same circumferential position P1 are grounded to the base plate 7 via the one support body 10.
The other support 10 has an insulating sheet interposed between the inner surface of the insertion hole 13 and the spiral tube portion 61, and is fixed in a state where the leg portion 11 and the base plate 7 are electrically insulated. As a result, the spiral tube portion 61 and the base plate 7 are electrically insulated.

In the electromagnetic induction heating device 1 configured as described above, by supplying an alternating current to the primary coil 5, a secondary induction current flows through the spiral tube portion 61 by electromagnetic induction. At this time, Joule heat corresponding to the electrical resistance is generated in the spiral tube portion 61, and the spiral tube portion 61 generates heat. And the to-be-heated substance can be heated by the heat of this spiral-tube part 61 being transmitted to the to-be-heated substance which flows in the spiral pipe part 61. FIG.
Here, the inlet pipe part 62 and the outlet pipe part 63 are formed so as to be separated from the outer side of the spiral pipe part 61, and each part 64 of the spiral pipe part 61 disposed at the same circumferential position P1 of the spiral pipe part 61 is provided. Since it becomes the ground potential, the inlet pipe portion 62 and the outlet pipe portion 63 also become the ground potential. Therefore, when the material to be heated is heated as described above, the secondary induction current does not flow through the inlet pipe portion 62 and the outlet pipe portion 63. That is, it is possible to reliably prevent the secondary induced current from leaking outside through the inlet pipe portion 62 and the outlet pipe portion 63.

  In addition, since all the portions 64 of the helical tube portion 61 arranged at the same circumferential position P1 are grounded, the length of the electric path of the secondary induction current in the helical tube portion 61 when the material to be heated is heated. This is the length of one turn (one winding) of the helical tube 61 with the same circumferential position P1 as a base point. That is, as shown in FIG. 4, the electrical path of the secondary induced current in the helical tube portion 61 is obtained by electrically connecting the independent single windings C1 in parallel at the same circumferential position P1 and grounding them. Is equivalent to Therefore, even if a large secondary induced current flows through the spirally wound spiral tube portion 61, the secondary induced voltage applied to the spiral tube portion 61 can be kept low.

  As described above, according to the electromagnetic induction heating device according to the present embodiment, there is no possibility that the secondary induction current flowing through the spiral tube portion 61 of the heating tube 6 leaks to the outside, and the second Since the secondary induction voltage can be set to a low voltage (for example, 1 V or more and 8 V or less) that does not cause an electric shock, the equipment for ensuring the safety of the operator is minimized, and the electromagnetic induction heating device 1 and this are connected. The manufacturing cost of the external device can be kept low.

In addition, since the electrical path of the secondary induced current in the spiral tube portion 61 is equivalent to the length of one round of the spiral tube portion 61 regardless of the number of turns of the spiral tube portion 61, the primary coil 5 and the spiral tube portion 61. Is equal to the number of turns of the primary coil 5. That is, even if the number of turns of the primary coil 5 is set to be smaller than that of the conventional case, the turn ratio (transformation ratio) between the primary coil 5 and the helical tube portion 61 can be easily set large. Therefore, even if an inexpensive low-frequency power source, which is a general commercial power source, is used as an input to the primary coil 5, a large secondary induction current (for example, 1000 amperes or more and less than 100,000 amperes) flows through the heating tube 6 to be heated. It becomes possible to heat a substance efficiently. Further, since the number of turns of the primary coil 5 can be set to be small, the volume of the primary coil 5 is reduced, and as a result, the electromagnetic induction heating device 1 can be easily designed.
Furthermore, if only the Joule heat generated in the circumferential portion of the spiral tube portion 61 is known, the Joule heat generated in the entire spiral tube portion 61 can be simply calculated by simply multiplying the Joule heat by the number of turns of the spiral tube portion 61. The design of the heating performance of the heating device 1 can also be performed easily.

In addition, since the respective portions 64 of the spiral tube portion 61 arranged at the same circumferential position P1 are electrically connected to each other, at least one of the portions 64 of the spiral tube portion 61 is connected to grounding wiring (such as a conductor or a wire). The work of grounding each portion 64 of the spiral tube portion 61 can be simply performed simply by electrically connecting the support 10).
Furthermore, when each part 64 of the helical tube part 61 arranged at the same circumferential direction position P1 is electrically connected by welding, each part 64 of the helical pipe part 61 is electrically connected by a separate member such as a conducting wire. In comparison, the number of components of the electromagnetic induction heating device 1 can be reduced. In addition, since a separate member such as a lead wire having low heat resistance compared to the heating tube 6 is not required, the lead wire is disconnected due to Joule heat generated in the heating tube 6. It is possible to reliably prevent the decrease in the temperature. Furthermore, since the number of steps for manufacturing the electromagnetic induction heating device 1 is reduced as the number of components decreases, it can be efficiently manufactured, and as a result, the manufacturing cost can be further reduced. .

Further, since the spiral tube portion 61 is formed by being wound in close contact, the distance between the circumferential portions of the spiral tube portion 61 is shortened, and the circumferential portions of the adjacent spiral tube portions 61 are warmed to each other. Since the matching heat retaining effect is increased, the Joule heat generated in the spiral tube portion 61 is difficult to escape from the outer surface of the spiral tube portion 61. As a result, the substance to be heated can be heated more efficiently.
Furthermore, since the dimension of the spiral tube portion 61 in the direction of the axis L1 can be reduced as compared with the case where the spiral tube portion 61 is formed in a spiral with a gap, the electromagnetic induction heating device 1 can be downsized. be able to. In addition, since the length of the shaft portion 41 of the iron core 4 can be set small, the magnetic and electrical losses are reduced, and the power factor of the electromagnetic induction heating device 1 is improved.
Furthermore, since the spiral tube portion 61 is wound in a close contact state, the spiral tube portion 61 is configured as one lump, so that the heating tube 6 can be easily attached to and detached from the support 10. . That is, the manufacturing efficiency and maintainability of the electromagnetic induction heating device 1 can be improved.

  Further, since the temperature sensor 8 is disposed in the same circumferential direction position P1 or the vicinity thereof in the spiral tube portion 61, or in the inlet tube portion 62 or the outlet tube portion 63, the temperature sensor 8 is connected to the spiral tube portion 61 by electromagnetic induction. Even if the next induced current flows, the voltage becomes 0 at the position where the temperature sensor 8 is attached, or the voltage becomes very low. Therefore, the temperature sensor 8 can measure the temperature of the heating tube 6 with high accuracy without being substantially affected by electromagnetic induction, and can control the heating of the material to be heated with high accuracy.

Further, the pressure adjusting valve 25 is provided in the discharge pipe portion 24 of the purge mechanism 22 so that the pressure inside the case 2 is set larger than the pressure outside the case 2 and equal to or lower than the pressure resistance value. Internal purge gas and other gases are always discharged outside the case 2. For this reason, it is possible to prevent foreign substances such as dangerous gas, moisture, and dust from entering the case 2 from the outside. The hazardous gas is handled by an external device such as a plant, and is, for example, a flammable gas such as hydrogen or a flammable liquid vapor such as gasoline.
Moreover, by allowing the purge gas to enter and exit between the inside and the outside of the case 2, the temperature rise in the case 2 due to the heat generation of the primary coil 5 and the heating tube 6 due to the alternating current and the secondary induction current is suppressed or prevented. be able to. In particular, the primary coil 5 can be efficiently cooled by spraying directly on the primary coil 5. For this reason, even if the primary coil 5 generates heat by passing an alternating current through the primary coil 5, the temperature rise of the primary coil 5 can be suppressed. In addition, it is possible to prevent the insulation from being deteriorated due to the temperature rise of the primary coil 5.

Further, by providing a pressure adjusting valve 25 for keeping the pressure inside the case 2 at a predetermined pressure in the discharge pipe portion 24 of the purge mechanism 22, foreign substances such as dangerous gas, moisture, dust and the like can be introduced from the outside into the case 2. It is possible to prevent the internal pressure of the case 2 from becoming excessively high while preventing intrusion.
Further, by stopping the supply of the alternating current to the primary coil 5 when the temperature of the heating tube 6 becomes equal to or higher than a predetermined temperature, for example, the temperature of the heating tube 6 suddenly rises suddenly, and such As the temperature rises, the internal pressure of the case 2 suddenly rises, and even if this rise cannot be suppressed by the pressure adjustment valve 25, the alternating current is stopped and the pressure supply device is stopped (supplied) By closing the valve or stopping the blower), it is possible to reliably prevent the internal pressure of the case 2 from becoming excessively high.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, the plurality of supports 10 are not limited to be arranged at equal intervals in the circumferential direction of the spiral tube portion 61, and may be arranged at unequal intervals. Moreover, the support body 10 is not limited to a plurality, and may be one, for example.
In addition, the electrical connection between the both ends 64A and 64B and the midway portion 64C of the spiral tube portion 61 arranged at the same circumferential position P1 and the base plate 7 is made to both the conductor and the single support 10A as in the above embodiment. For example, only one may be used. That is, one support 10 </ b> A is electrically connected to both end portions 64 </ b> A and 64 </ b> B and halfway portions 64 </ b> C and the base plate 7 of the helical tube portion 61 disposed at the same circumferential position P <b> 1, for example, similarly to the other support 10. It may be insulated.

Furthermore, the circumferential portions of the spiral tube portions 61 that are adjacent to each other in the direction of the axis L1 of the spiral tube portion 61 are not limited to closely contacting each other in the circumferential direction, and may be closely contacted only at the same circumferential position P1, for example They may be arranged at intervals without being in close contact with each other. In addition, as long as the circumferential portions of the adjacent spiral tube portions 61 are in close contact with each other at least at the same circumferential position P1, each portion 64 of the spiral tube portions 61 disposed at the same circumferential position P1 as in the above embodiment. Can be joined by welding.
Moreover, although each part 64 of the helical tube part 61 distribute | arranged to the same circumferential direction position P1 was electrically connected by welding, it may be electrically connected by separate members, such as conducting wire, for example. Moreover, each part 64 of the helical tube part 61 distribute | arranged to the same circumferential direction position P1 does not need to be electrically connected mutually, and should just be earth | grounded at least.

Further, the number of turns of the spiral tube portion 61 is not limited to a plurality, and may be one, for example, as long as at least both end portions 64A and 64B of the spiral tube portion 61 are arranged in the direction of the axis L1 of the spiral tube portion 61. In this case, both end portions 64A and 64B of the spiral tube portion 61 may be electrically connected by welding or the like.
Further, the primary coil 5 and the spiral tube portion 61 are not limited to being concentrically arranged as in the above-described embodiment, but at least by supplying an alternating current to the primary coil 5, the primary coil 5 and the spiral tube portion 61 are connected to the spiral tube portion 61 by electromagnetic induction. What is necessary is just to arrange | position relatively so that a next induced current may generate | occur | produce.

Further, the introduction pipe portion 23 of the purge mechanism 22 is not limited to be formed so as to blow the purge gas introduced into the case 2 directly onto the primary coil 5, but is simply formed so as to be introduced into the case 2. May be.
Further, the pressure adjusting valve 25 may not be provided in the discharge pipe portion 24 of the purge mechanism 22.

DESCRIPTION OF SYMBOLS 1 Electromagnetic induction heating apparatus 2 Case 22 Purge mechanism 23 Introduction pipe part 24 Discharge pipe part 25 Pressure adjustment valve 4 Iron core 5 Primary coil 6 Heating pipe 61 Spiral pipe part 62 Inlet pipe part 63 Outlet pipe part 64 Each part 64A, 64B End part ( Each part)
64C Midway (each part)
L1 Axis P1 Same circumferential position

Claims (3)

An iron core, a spiral tube formed by spirally winding the iron core, and an inlet tube and an outlet tube connected to both ends of the spiral tube and extending radially outward of the spiral tube A conductive heating tube having a portion, a primary coil that is wound around the iron core and generates a secondary induction current in the helical tube portion by electromagnetic induction by supplying an alternating current, and the iron core inside the heating A case that accommodates the tube and the primary coil, and a purge mechanism that allows purge gas to enter and exit between the inside and the outside of the case ,
The spiral tube portion is formed by winding in a close contact state,
Both ends of the spiral tube portion are arranged at the same circumferential position so as to be arranged in the axial direction of the spiral tube portion,
Each part of the spiral tube portion arranged at the same circumferential position is electrically connected to each other by being joined to each other by welding, and grounded ,
The frequency of the alternating current supplied to the primary coil is 10 Hz to 400 Hz,
The secondary induced current is 1000 amps or more and less than 100,000 amps,
The secondary induction voltage applied to the heating tube by the electromagnetic induction is 1 V or more and 8 V or less,
The electromagnetic induction heating device , wherein the purge mechanism is configured to directly blow the purge gas introduced into the case onto the primary coil . Provided in the discharge pipe portion of the purge mechanism for discharging the casing inside the air containing the purge gas to the outside, and pressure regulating valve for maintaining the pressure inside the casing to a predetermined pressure, the temperature of the heating tube A temperature sensor to be measured, and a power supply control unit that stops the supply of the alternating current to the primary coil based on the measurement result when the measurement result of the temperature sensor becomes equal to or higher than a predetermined temperature. The electromagnetic induction heating device according to claim 1 . Covering the entire heating tube, provided with a heat insulating material that does not let the Joule heat generated in the spiral tube portion and the heat of the heated material flowing inside the heating tube escape to the outside of the heating tube,
The electromagnetic induction heating apparatus according to claim 1, wherein the primary coil is disposed outside the heat insulating material.

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