JP2004214039A - Fluid heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid heater using electromagnetic induction heating which is superior in heating, is easy to electrically control, and is friendly to the environment. <P>SOLUTION: An electromagnetic induction heater 2 is inserted inside a pipe 1 and a coil 3 is wound around its periphery and the initial winding portion and the winding terminating portion are connected to a high frequency AC power source 4. In addition, both sides of the pipe 1 are provided with pipe junctions 5 to be coupled to a fluid circulation path. The heater 2 is zigzag folded along the cylindrical side in its longitudinal direction, resulting in a plurality of corrugations (a) projected in the direction of a central axis. Then, the corrugations (a) are formed diagonally to the cylindrical longitudinal direction so that the line of magnetic force generated by the coil 3 intersects the side of the corrugations (a). <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fluid heater installed in a circulation path of a fluid such as water or steam to heat a fluid.
[0002]
[Problems to be solved by the invention]
When a heater is installed in the fluid circulation path to heat the fluid, if a heating element such as a nichrome wire or a semiconductor ceramic is brought into direct contact with the fluid and heated, the thermal efficiency is improved, but the wiring is difficult and the contact area is small. Heat conduction efficiency is poor, and uneven heating is likely to occur.
Therefore, it has been common to supply a heat medium such as superheated steam from the outside to the heat exchanger and heat the fluid with the heat.
However, electric control of the heat exchanger is difficult, and the speed of temperature rise is slow, so that temperature control such as rapid heating is difficult.
In addition, there is a problem that the radiant heat of the boiler and the combustion gas have a bad influence on the surrounding environment and the working environment is deteriorated.
[0003]
In this regard, in the electromagnetic induction heating, the heating element is heated in a non-contact manner, so that no wiring is required. Since the contact area can be expanded by enlarging the heating element, the fluid can be uniformly heated.
Further, temperature control by electric control is easy, the temperature rise speed is fast, and radiant heat and combustion gas are not generated, so that the influence on the environment is small.
[0004]
When heating a fluid using this electromagnetic induction heating, it is efficient to wind the coil along the flow of the fluid, but in this case, the heating surface must be orthogonal to the direction of the magnetic lines of force generated from the coil. is there.
For this reason, the heating element must be installed facing the flow of the fluid, and the flow of the fluid is obstructed.
On the other hand, when the heating element is installed in parallel with the flow of the fluid, the direction of the magnetic field lines coincides with the direction of the heating surface, and no eddy current is generated, so that the heating element does not generate heat.
[0005]
Therefore, the present invention provides a fluid heater by electromagnetic induction heating that is excellent in heating performance, is easy to control electric, and is environmentally friendly by realizing a heating element that can generate heat without obstructing the flow of fluid. It was made for the purpose.
[0006]
[Means for Solving the Problems]
In order to achieve such an object, the present invention is configured as follows.
[0007]
That is, in the fluid heater of the present invention, a heating element is inserted inside a tube through which a fluid flows, and a coil for flowing a high-frequency current is wound around the outside of the tube. The above object is achieved by forming a belt-like plate located in the radial direction and continuing along the flow of the fluid, and further tilting the band-like plate with respect to the direction of the magnetic lines of force generated from the coil.
[0008]
Preferably, the belt-like plate is a pleated projection formed by bending a side surface of a cylinder in a zigzag manner along a length direction.
[0009]
Also, preferably, the distance from the axis of the fold-like projection is alternately shifted toward and away from each other.
[0010]
Preferably, the band-shaped plate is a spiral plate that turns around the axis of the tube.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0012]
FIG. 1 is a cutaway side view of a fluid heater embodying the present invention.
In the fluid heater, a heating element 2 for electromagnetic induction heating is inserted inside a tube 1, and a coil 3 is wound outside the tube 1, and the start and end of the winding are connected to a high-frequency AC power supply 4.
In addition, pipe joints 5 are provided at both ends of the pipe 1 and connected to a fluid circulation path.
[0013]
FIG. 2 shows a cross-sectional view of a heating element embodying the present invention.
The heating element 2 bends the side surface of the cylinder in a zigzag manner along the length direction, and protrudes a large number of pleats a toward the axis.
At this time, the fold-shaped protrusion a is formed obliquely with respect to the length direction of the cylinder such that the side surface of the fold-shaped protrusion a intersects with the magnetic force line generated from the coil 3.
In the figure, the height of the ridge line of the pleated projection a is made the same, but as shown in FIG. You may.
This makes it possible to fill the large space created in the axial center portion, make the flow of the fluid uniform, and reduce heating unevenness.
If there is a large space in a part of the cross section, a portion that easily flows and a portion that does not easily flow are formed, and the flow of the fluid is not concentrated uniformly in the portion that easily flows.
For this reason, it is impossible to uniformly heat the fluid inside.
[0014]
The material of the heating element 2 is preferably an iron-based magnetic material such as SUS304 (stainless steel) which has a large electric resistance and easily changes to heat when an eddy current flows.
[0015]
As shown in FIG. 4, the heating element 2 may be formed of a screw-type belt-like plate that spirally turns the axis of the tube 1.
Thus, similarly to the heating element 2 shown in FIGS. 2 and 3, a band-shaped plate having a hollow axis, continuous along the flow of the fluid, and inclined with respect to the direction of the magnetic force lines generated from the coil is formed. be able to.
[0016]
The fluid heater embodying the present invention has the above-described configuration, and connects the pipe joints 5 provided at both ends of the pipe 1 to a fluid circulation path. The heating element 2 is directly heated by the heating element 2.
At this time, as shown in FIG. 5, an eddy current c flows at the intersection of the magnetic force line b and the pleated protrusion a, and the heating element 2 generates heat by electric resistance.
Further, the fluid flowing in the pipe 1 passes through the gap of the ridge-shaped protrusion a and is uniformly heated.
In the case where the amount of heat of the fluid heater of the present invention is insufficient, the amount of heat of the heater can be increased by adding a large number of heaters in series via the pipe joint portion 5.
[0017]
【The invention's effect】
As described above, in the fluid heater according to the present invention, since the heating element is configured by the band-shaped plate continuous along the flow of the fluid, the fluid in the fluid can flow smoothly without obstructing the flow of the fluid. . Further, since the belt-like plate is inclined with respect to the direction of the magnetic field lines generated from the coil, the eddy current is generated when the belt-like plate and the magnetic field lines intersect, and the heating element can generate heat.
As described above, since the heating element is directly heated, the thermal efficiency is good, there is no radiant heat and there is no combustion gas, so the surrounding environment is not degraded, there is no danger of poisoning or explosion, etc. An ideal fluid heater capable of performing continuous heating while flowing a fluid using agile electromagnetic induction heating can be realized.
[Brief description of the drawings]
FIG. 1 is a partially cutaway side view of a fluid heater embodying the present invention.
FIG. 2 is a cross-sectional view of a heating element embodying the present invention.
FIG. 3 is a modification of FIG. 2;
FIG. 4 is a schematic view of a modified example of a heating element embodying the present invention.
FIG. 5 is a schematic diagram illustrating the operation of a heating element embodying the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Tube 2 Heating element 3 Coil 4 High frequency AC power supply 5 Pipe joint a Fold-shaped protrusion b Magnetic force line c Eddy current

Claims (4)

Insert the heating element inside the pipe through which the fluid passes,
On the outside of this tube, a coil for flowing high-frequency current is wound,
The heating element,
Located radially from the axis of the pipe,
And it is composed of a continuous strip along the flow of fluid,
Further, the fluid heating heater is characterized in that the band-shaped plate is inclined with respect to the direction of the line of magnetic force generated from the coil. The fluid heater according to claim 1, wherein the strip-shaped plate is a pleated protrusion formed by zigzag bending a side surface of a cylinder along a length direction. 3. The fluid heater according to claim 2, wherein a distance from the axis of the pleat is alternately shifted. The fluid heater according to claim 1, wherein the band-shaped plate is a spiral plate that turns around the axis of the tube.

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