JPH05290960A - Electric heating device - Google Patents

Abstract

PURPOSE:To enable the quick heating of a fluid to be easily undertaken by providing metallic pipes of spiral form as a flow passage for a fluid coaxially with a coil, and connecting the pipes to each other in such a way as forming a close circuit electrically. CONSTITUTION:Metallic pipes 21 are spirally formed inside a line coaxial with a coil 3, and connected to each other with brazing or welding via a connecting body 25, thereby forming a close circuit electrically. Also, an insulation material 26 covers the pipes 21 and enhances an insulation effect. When the coil 3 is fed with power from an alternating current power supply 4, the pipes 21 are heated, due to induction heating. On the other hand, when a fluid 2 is caused to flow from an upper level, heat is transferred to the fluid 2 from the heated pipes 21, and the fluid 2 is thereby heated. The thermal capacity of the pipes 21 is reduced and the contact area of the fluid 2 is enlarged by forming the whole of the device cylindrically as described. The quick heating of the fluid 2 can, therefore, be easily undertaken.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric heating device for inductively heating a fluid.

[0002]

2. Description of the Related Art FIG. 5 is a sectional view of a conventional fluid electric heating apparatus disclosed in, for example, Japanese Patent Laid-Open No. 62-58590. Figure 6
FIG. 6 is a sectional view taken along line VI-VI in FIG. 5. 1 in the figure
Is a cylindrical metal heated object, and the fluid passage 12
Are provided in plural. 5 is a medium hole pipe, 2 is a fluid,
Reference numeral 3 is a cylindrical coil for induction heating, and 4 is an AC power supply for supplying power to the coil 3.

Next, the operation will be described. When power is supplied to the coil 3 from the AC power supply 4, the object 1 to be heated is heated by induction heating. When the fluid 2 passes through the flow path 12 of the heated body 1, it receives heat from the heated body 1 and is heated.

[0004]

Since the conventional electric heating device is constructed as described above, the volume of the object to be heated is large and the heat capacity is large, so that the temperature of the object to be heated is hard to rise, and the flow path Since the surface area is small, it is difficult to rapidly heat the fluid.

An object of the present invention is to solve the above problems, and an object thereof is to obtain an electric heating device capable of rapidly heating a fluid.

[0006]

An electric heating device according to the present invention is constructed by spirally forming a metal pipe as a fluid flow path coaxially with an induction heating coil or by using a metal pipe in an axial direction. It has a flow path that reciprocates, and is formed in a tubular shape as a whole, and the metal pipes are electrically connected so as to form a closed circuit.

[0007]

In the electric heating apparatus according to the present invention, the object to be heated is composed of a metal pipe having a small heat capacity so that the metal pipe can be rapidly heated, and the contact area with the fluid is widened to transfer heat to the fluid. The fluid can be heated rapidly since

[0008]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. 1 and 2, 2 to 4 are the same as or equivalent to the conventional example. Reference numeral 21 is a metal pipe as a flow path, which is formed in a spiral shape inside the coil coaxially. twenty five
Is a connecting body, which is an electrically closed circuit in which metal pipes are connected by brazing or welding. 26 is a heat insulating material covering the metal pipe.

When power is supplied to the coil 3 by the AC power source 4, the metal pipe 21 is heated by induction heating. On the other hand, when the fluid 2 is flown from above in FIG. 1, heat is transferred from the heated metal pipe 21 to heat the fluid 2.

In this embodiment, as the connecting body 25, the metal pipes are brazed to form an electrically closed circuit. However, the winding start and the winding end of the metal pipes are electrically connected by conductors. Also has the same effect as the above embodiment.

Embodiment 2. FIG. 3 shows a sectional view of another embodiment. FIG. 4 is a sectional view taken along line IV-IV in FIG. The metal pipe is reciprocated coaxially inside the tubular coil 3 in its axial direction, that is, in the vertical direction in FIG. 3, and is formed into a tubular shape as a whole. In FIG. 4, reference numeral 25 denotes a connecting body, which is a metal pipe.
The 21 parts are connected by brazing or welding to form an electrically closed circuit. Further, even if the winding start and winding end of the metal pipe 21 are connected by a conductor, the same effect as that of the above-described embodiment can be obtained.
Further, in the above-described embodiment, the example in which the metal pipe 21 is attached to the inside of the coil 3 has been shown.

[0012]

As described above, according to the present invention, the metal pipe is formed in a spiral shape coaxially with the induction heating coil, or the metal pipe is axially reciprocated to form a tubular shape as a whole. By forming the metal pipe, the heat capacity of the metal pipe is reduced and the contact area with the fluid is widened, so that rapid heating of the fluid can be facilitated.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an electric heating device according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view showing an electric heating device according to another embodiment of the present invention.

4 is a cross-sectional view taken along the line IV-IV in FIG.

FIG. 5 is a cross-sectional view showing a conventional electric heating device.

6 is a sectional view taken along line VI-VI of FIG.

[Explanation of symbols]

 2 fluid 3 coil 21 metal pipe 25 connection

Claims (2)

[Claims] 1. An electric heating device comprising a tubular coil, wherein the coil is energized to induction-heat a fluid, and a spiral metal pipe is provided coaxially with the coil as a flow path for the fluid. An electric heating device characterized in that the metal pipes are electrically connected so as to form a closed circuit. 2. An electric heating device comprising a tubular coil, wherein the coil is energized to inductively heat a fluid, wherein a flow path for the fluid that reciprocates in the axial direction of the coil is coaxial with the coil. An electric heating device comprising: a metal pipe having a tubular shape as a whole, and the metal pipes being electrically connected so as to form a closed circuit.