JP5358660B2 - Fluid heating device using induction heating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact fluid heating apparatus using induction heating which has high heating efficiency. <P>SOLUTION: A fluid heating apparatus comprises: a fluid channel 11 which includes straight tubes 12 made of a conductive metal material arranged in parallel with gaps therebetween, and U-shaped connection paths 13 arranged on one side and the other side of each of the straight tubes 12 to connect all the straight tubes 12 in series, and which has an inlet and an outlet while its entire part forms one flow channel; and an induction coil 20 which is wound around so as to surround all the straight tubes 12, and which flows high-frequency induction current through each of the straight tubes 12. The both sides of the straight tubes 12 are supported by tube plates 14 and 15, and the straight tubes 12 are made of the metal material which is non-magnetic and corrosion-resistant. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

The present invention relates to a fluid heating apparatus using induction heating having a small size and high heating efficiency.

Conventionally, in heat treatment of fluid foods, chemicals, etc., heat exchangers that use harmless hot water or saturated water vapor of 100 ° C. or higher as a heating medium have been used (for example, patents) Reference 1).
However, when a heating medium such as warm water or saturated steam is used, equipment such as a boiler, pump, and piping for continuously supplying these heating media is required, which increases the size of the device and restricts the installation location. Is done.

In order to solve the problem in the heat exchanger using the heating medium, there has been proposed a heat exchanger that is miniaturized by using electromagnetic induction heating.
For example, Patent Document 2 discloses a heat exchanger that is made of a material that can be heated by electromagnetic induction by a work coil and that has a work coil for generating magnetic flux disposed outside a tubular housing that exchanges heat with a fluid passing through a flow path. It is disclosed.
Further, Patent Document 3 has a heat generating portion provided with a magnetic material, and has a coil that is wound around the outside of a cylindrical fluid passage through which a fluid passes, and allows a high-frequency current to flow through the heat generating portion. A fluid heating apparatus using induction heating is disclosed.
Patent Document 4 discloses a fluid heating device in which induction coils are arranged so as to surround a plurality of tube groups arranged in parallel to each other.

JP 2003-235473 A JP 2005-98553 A JP 2005-222781 A Japanese Patent No. 3642415

However, the heat exchangers (fluid heating devices using induction heating) described in Patent Documents 2 and 3 are small in size because coils for generating high-frequency induction current are arranged outside the individual tubular bodies. Is difficult.
On the other hand, in the fluid heating device described in Patent Document 4, since the induction coil is disposed so as to surround a plurality of tube groups, the device can be reduced in size. However, the fluid is parallel to the plurality of tubes. It is flowing. Therefore, for example, when heating highly viscous fluids where heat transfer is difficult to proceed, or when heating is performed with a small temperature gradient to avoid deterioration due to overheating, the heat transfer time is lengthened by taking a longer heating path. An attempt to secure it will increase the size of the device.

This invention is made | formed in view of this situation, and it aims at providing the fluid heating apparatus using the induction heating which is small and has high heating efficiency.

The fluid heating apparatus using induction heating according to the present invention in accordance with the above object includes a straight pipe made of a nonmagnetic metal material having a gap and arranged in parallel, and one side of each straight pipe And a U-shaped connecting path that connects all the straight pipes in series, and a fluid passage that has an inlet pipe and an outlet pipe to form a single flow path, A fluid heating device wound around the straight pipes and having an induction coil for passing a high-frequency induction current to each of the straight pipes ;
Both sides of the straight pipe are supported by a pipe plate, and a tube cover provided on one side of the straight pipe is provided with a first lid cover through which the inlet pipe and the outlet pipe pass, and the straight pipe is provided. The tube cover provided on the other side of the tube is provided with a second lid cover provided with the U-shaped connecting path for connecting the ends of the adjacent straight tubes so as to be attached and removable in a sealed state. Yes.

In the fluid heating apparatus using induction heating according to the present invention, the straight pipe may be made of the metal material having non-magnetic and corrosion resistance.

In the fluid heating apparatus using induction heating according to the present invention, corrugation processing may be performed on at least a portion excluding both ends of the straight pipe.

In the fluid heating apparatus using induction heating according to the present invention, a stirring member may be disposed at least in part inside the straight pipe.

Since the fluid heating apparatus using induction heating according to the present invention does not use a heating medium such as warm water or saturated steam, facilities such as a boiler, a pump, and piping for continuously supplying these heating media are required. However, the apparatus can be downsized and heating can be started or stopped rapidly. Moreover, temperature control is also easy by adjusting the high frequency electric power sent through an induction coil.
In addition, since the fluid to be heated is reversed in the flow direction by the U-shaped connecting path and repeatedly heated in the straight pipe, the heat transfer time is ensured for a long time and heating with a small temperature gradient is possible. Become. Therefore, the heating efficiency can be increased and the quality of the food after heating can be kept high.
Furthermore, since the induction coil for passing the high-frequency induction current is wound so as to surround all the straight pipes, the apparatus can be further downsized as compared with the case where the induction coils are wound around the individual straight pipes.

In particular, in this fluid heating apparatus, both sides of each straight pipe are supported by a tube plate, and a U-shaped connecting path is formed in a lid cover that is detachably provided on the tube plate in a sealed state. Inspection and cleaning of the inside of the animal passage can be reliably performed in a short time by removing the lid cover.

Furthermore, since each U-shaped connecting path connects adjacent straight pipes, the structure of the guide passage becomes simple, and manufacture and maintenance of the fluid heating device are facilitated.

In fluids heating apparatus using an induction heating according to the present invention, together with the straight pipe is the case of a metallic material having a non-magnetic and corrosion resistant, can be heated such as liquid food more safely and hygienically, The life of the apparatus can be improved.

In the fluid heating apparatus using induction heating according to the present invention, when corrugation is performed on a portion excluding both ends of the straight pipe, turbulent flow is easily formed inside the straight pipe, and induction heating is performed. The heat transfer between the straight pipe and the fluid becomes larger. Therefore, the overall heat transfer coefficient of the fluid heating device can be increased.

In fluids heating apparatus using an induction heating according to the present invention, if it has a stirring member in at least a portion of the inside of the straight pipe, to continuously divide and mix the fluids in fluids passage And the heating efficiency of the fluid can be increased.

It is a schematic explanatory drawing of the fluid heating apparatus using the induction heating which concerns on one embodiment of this invention. (A) is the schematic which shows the external appearance of the cover of the fluid heating apparatus, (B) is the schematic which shows the state which removed the cover. It is explanatory drawing which shows the arrangement | positioning state of a straight pipe and a U-shaped connection path.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
With reference to FIGS. 1-3, the fluid heating apparatus 10 using the induction heating which concerns on one embodiment of this invention is demonstrated.
As shown in FIG. 1, the fluid heating device 10 is provided on a plurality of straight pipes 12 made of a metal material having conductivity and arranged in parallel with a gap, on one side and the other side of each straight pipe 12. It has a single continuous fluid passage 11 formed by a plurality of U-shaped connecting passages 13, an inlet pipe 18, and an outlet pipe 19 through which the fluid to be heated moves.
The fluid heating device 10 further includes an induction coil 20 that is wound so as to surround the straight pipe group 21 including all the straight pipes 12 and allows a high-frequency induction current to flow through each of the straight pipes 12.

Each straight pipe 12 is supported at both ends by tube plates 14 and 15, and a plurality of U-shaped connecting passages 13 are formed inside lid covers 16 and 17 detachably provided on the tube plates 14 and 15. Has been. Further, as shown in FIG. 2A, a plurality of flanges 24 having U-shaped grooves are provided at equal intervals on the outer periphery of the lid covers 16 and 17. Further, an inlet pipe 18 and an outlet pipe 19 are attached to one lid cover 17 so as to penetrate the main body of the lid cover 17. As shown in FIG. 2 (B), flanges 23 having grooves are provided on the outer circumferences of the tube plates 14 and 15 at positions corresponding to the flanges 24 provided on the outer circumferences of the cover covers 16 and 17, respectively. A lid cover fixing bolt 25 is rotatably mounted between the grooves via a pin or the like.
The lid covers 16 and 17 are attached to the outside of the tube plates 14 and 15, respectively, and the lid cover fixing bolt 25 attached to the flange 23 of the tube plates 14 and 15 is passed through the U-shaped groove of the flange 24, and the lid is a cap nut. When the cover fixing nut 26 is fastened with a washer (not shown) disposed therebetween, all the straight pipes 12, the U-shaped connecting path 13, the inlet pipe 18, and the outlet pipe 19 are connected in series. A fluid passage 11 is formed.
Since the lid covers 16 and 17 can be easily attached and detached, the inspection and cleaning of the fluid passage 11 can be reliably performed in a short time.

Since the straight pipe 12 is heated by induction heating to transmit itself to the fluid passing through the inside, it has conductivity and necessary heat resistance so that induction heating is possible. Must be. Moreover, it is preferable to have corrosion resistance so as not to contaminate the fluid due to corrosion.
Examples of materials that can be used for the straight pipe 12 include iron-based alloys such as austenitic stainless steel (SUS316L, etc.) and ferritic stainless steel, which are metal materials having corrosion resistance, nickel-based alloys, titanium (TTP340, etc.) ), Molybdenum and the like. In order to suppress the attenuation of the induction magnetic field reaching the straight pipe 12 located inside the straight pipe group 21, it is preferable to use a nonmagnetic metal material such as austenitic stainless steel or titanium.
The eddy current due to electromagnetic induction increases as it approaches the surface of the tube and decreases exponentially toward the inside (skin effect). Therefore, these nonmagnetic materials are disposed only on the outer surface of the straight tube 12. Also good.
The diameter, thickness, and length of the straight pipe 12 are not particularly limited, but in this embodiment, TTP340-W having an outer diameter of 25.4 mm, a thickness of 1.5 mm, and a length of 880 mm is used as the straight pipe 12. Used.

The straight pipes 12 are arranged with a gap therebetween to prevent the induced current from being short-circuited. In order to efficiently arrange a large number of straight pipes 12 within a certain volume, for example, as shown in FIG. 3, all the straight pipes 12 are arranged at equal intervals so as to be positioned at the apexes of an equilateral triangle.
The U-shaped connecting path 13 connects all the straight pipes 12 in series, and has one inlet and an outlet, and forms one flow path as a whole. It is formed inside the lid covers 16, 17 and connects the adjacent straight pipes 12. An example of the arrangement of the U-shaped connection path 13 is shown by a solid line and a broken line in FIG. Note that IN and OUT represent the straight pipe 12 to which the inlet pipe 18 and the outlet pipe 19 are connected, respectively.

A corrugated tube with corrugation (corrugated) applied to the portion excluding both ends may be used as a straight tube. In this case, turbulence is likely to be generated in the fluid moving inside, and the overall heat transfer coefficient Is preferable. Further, a stirring member may be provided for promoting the mixing of the fluid moving inside by dividing the flow of the fluid inside the straight pipe and guiding each in a different direction. The shape of the stirring member and the material constituting the stirring member are not particularly limited, but are preferably made of a material having corrosion resistance. In particular, when the stirring member is made of a metal material having high thermal conductivity, if the stirring member and the inside of the straight pipe are kept in contact with each other, the heat generated in the straight pipe by induction heating can be transferred to the stirring member. The center of the flow of the fluid moving in the passage 19 can also be heated, so that heating can be performed more uniformly.
However, when the stirring member is made of a metal material, in order to prevent battery corrosion on the contact surface with the straight pipe, use the same material as that of the straight pipe, or an electrical insulation treatment on the contact face with the straight pipe It is necessary to apply.
Specific examples of the stirring member include those described in JP-A-2005-222781 (page 7, lines 1 to 20).

The tube plates 14 and 15 hold the both ends of the straight tube 12 penetrating each other. As a method for inserting and fixing the straight pipe 12 to the tube plates 14 and 15, known methods such as screwing, pipe expansion, fitting through a sealing material, brazing, and welding can be used.
Although the material which comprises the tube sheets 14 and 15 will not be restrict | limited especially if it has required intensity | strength, heat resistance, and corrosion resistance, Stainless steel etc. are used preferably. Since the induced current flows along the circumferential direction of the straight pipe 12, it is not necessary to configure the tube plates 14 and 15 with an insulating material or to dispose an insulating material between the straight pipe 12. However, in order to suppress heat conduction from the straight pipe 12, a sealing material having low heat conductivity may be disposed between the straight pipe 12 and the tube plates 14 and 15.

Openings are arranged in the lid covers 16 and 17 so as to coincide with the positions of the ends of the straight pipe 12 when joined to the tube plates 14 and 15, respectively, so that adjacent openings are connected to each other. A plurality of U-shaped connection paths 13 are formed. When the lid covers 16 and 17 are respectively joined to the tube plates 14 and 15, the U-shaped connection path 13 connects the straight pipes 12, and the single flow from the inlet pipe 18 to the outlet pipe 19 as a whole. It arrange | positions so that the animal channel | path 11 may be formed.
As a material constituting the lid covers 16 and 17, any material having heat resistance and corrosion resistance can be used. In the present embodiment, lid covers 16 and 17 are made of a stainless steel casting using stainless steel for casting (SCS14).
A gasket 22 is disposed between the lid covers 16 and 17 and the tube plates 14 and 15. Examples of the material of the gasket 22 include synthetic rubber such as EPDM (ethylene-propylene-diene rubber) excellent in heat resistance and weather resistance.
Alternatively, an O-ring may be arranged between all the straight pipes 12 and the U-shaped connecting path 13 instead of or together with the gasket 22. Thereby, the cover covers 16 and 17 can be attached to the tube plates 14 and 15 in a sealed state.

An inlet pipe 18 and an outlet pipe 19 are attached to the lid cover 17 so as to penetrate the lid cover 17. One end of the inlet pipe 18 and the outlet pipe 19 is connected to one of the straight pipes 12 when the lid cover 17 is attached to the tube plate 15, and the other end is connected to another process via a flange (not shown). Connected.
As the material used for the inlet pipe 18 and the outlet pipe 19, any material having heat resistance and corrosion resistance can be used. Austenitic stainless steel (SUS316L, etc.), titanium (TTP340, etc.) used for the straight pipe 12 In addition to molybdenum, iron-based or nickel-based alloys such as magnetic stainless steel can also be used.

It is preferable that a heat insulating material is wound around the outer periphery of the tube group 21 to suppress release of heat generated from the straight pipe 12 to the outside. Examples of the material constituting the heat insulating material include glass fiber which is an insulator that is not heated by an induced current. The heat insulating material may be only one layer around the outer periphery of the tube group 21, or may be wound in two or more layers.
Further, in order to suppress the release of heat generated from the straight pipe 12 to the outside, a heat insulating material may be further wound around the outer periphery of the induction coil 20. Examples of the material of the heat insulating material used here include cork having higher heat insulating properties in addition to glass fiber and the like.

An induction coil 20 that causes an induction current for heating to flow through the straight pipe 12 is wound so as to surround the entire tube group 21. When the heat insulating material is wound around the tube group 21, the induction coil 20 is wound around the outer periphery of the heat insulating material with a gap of about 0.5 to 3 mm, for example.
As the linear conductor constituting the induction coil 20, a good conductor such as copper can be cited. The diameter of the linear conductor, the pitch of the coil (interval between adjacent linear conductors), and the number of turns are the size of the fluid heating device 10 using induction heating, the heating temperature, the high-frequency current and the frequency applied to the induction coil 20 It adjusts suitably according to etc. In order to cool the induction coil 20, the induction coil 20 may be formed of, for example, a copper tube, and the cooling water may flow inside.
The temperature distribution of the fluid passage 11 may be adjusted by changing the pitch of the induction coil 20 over the longitudinal direction of the tube group 21. Further, the outer periphery of the induction coil 20 is covered with an insulating material made of a polyolefin-based resin having a heat resistant temperature of about 130 ° C., for example.

Both ends of the induction coil 20 are connected to a high frequency power source (not shown). The frequency of the high frequency passed through the induction coil 20 is, for example, 20 to 50 kHz, and the power at this time depends on the size of the fluid heating device 10, the set temperature inside the fluid passage 11, etc. Is within.

The fluid heating device 10 heats and sterilizes a one-phase fluid such as water, oil, or a chemical solution, or a solid-liquid two-phase fluid such as a fluid food that has a high viscosity and is difficult to transfer heat. In addition, it can be used for cooking and emulsification of fluid foods. In particular, when the inner peripheral portion of the fluid passage 11 and the stirring member are made of a material having corrosion resistance, the fluid passage 11 can be suitably used for heat treatment of fluid foods where hygiene is important.
The fluid may have a high viscosity such as a jam, or may contain a solid such as a juice containing pulp.

The present invention is not limited to the above-described embodiment, and can be changed without changing the gist of the present invention. For example, a part or all of the above-described embodiment and modification examples are combined. Thus, a fluid heating apparatus using induction heating according to the present invention is included in the scope of the present invention.
For example, in the above-described embodiment, the number of straight pipes is an even number and the inlet pipe and the outlet pipe are mounted on the same lid cover. Each may be mounted on a different lid cover.
In the above embodiment, the fluid passage has a straight pipe and a U-shaped connecting passage formed inside the lid cover. However, the fluid passage is formed by bending one pipe. It may be formed.

Moreover, in the said embodiment, the flange which has a U-shaped groove | channel is provided in the tube plate and the cover cover, and the cover cover is fixed to the tube plate by the cover cover fixing lock bolt and nut. An annular flange may be provided on the outer periphery of the cover, and the lid cover may be fixed to the tube plate with a clamp band.
Moreover, in the said embodiment, although all the straight pipes are arrange | positioned at equal intervals so that it may be located in the vertex of an equilateral triangle, you may arrange | position a straight pipe in multiple annular | circular shape on several concentric circles.

10: Fluid heating device, 11: Fluid passage, 12: Straight pipe, 13: U-shaped connection path, 14, 15: Tube plate, 16, 17: Lid cover, 18: Inlet pipe, 19: Outlet pipe, 20: induction coil, 21: straight pipe group, 22: gasket, 23, 24: flange, 25: lid cover fixing bolt, 26: lid cover fixing nut

Claims (3)

A straight pipe made of a non-magnetic metal material that is arranged in parallel with a gap, and a U-shape on one side and the other side of each straight pipe that connects all the straight pipes in series A fluid passage having an inlet pipe and an outlet pipe , and forming a flow path as a whole,
Wherein all wound so as to surround a straight tube, a liquid food, heating apparatus for chromatic an induction coil for flowing a high-frequency induced current in each of said straight pipe,
Wherein both sides of the straight pipe is supported by the tube plate Rutotomoni, the tube plate provided on one side of the straight tube, a first cap covering said inlet pipe and said outlet pipe penetrates is provided, said straight The tube cover provided on the other side of the tube is provided with a second lid cover provided with the U-shaped connecting path for connecting the ends of the adjacent straight tubes so as to be attached and removable in a sealed state. fluids heating apparatus using an induction heating, characterized in that there. The fluid heating apparatus using induction heating according to claim 1, wherein corrugation is performed at least on a portion excluding both ends of the straight pipe. The fluid heating apparatus using induction heating according to claim 1 or 2 , wherein a stirring member is disposed at least in part inside the straight pipe.

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