JPH09306648A - Fluid heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent fused damages on a resin tube and perform heating of a fluid safely and certainly by installing a coil-shaped heat emitting body on the external surface of the resin tube, and enclosing the heat emitting body with multiple layers of a resin tape which is thin and flexible. SOLUTION: A fluid heater concerned is structured so that a coil-shaped heat emitting body 2 is installed at the periphery of a resin tube 1 in which a liquid or gas flows. This heat emitting body is enclosed with multiple layers of a resin tape 3 which is thin and flexible. Owing to its flexibility, the tape 3 intrudes easily between the wires of the heat emitting body 2 to restrain the heat emitting body 2 from three directions, which should lessen the change in the wire spacing of the heat emitting body 2 originating from a thermal load. This heater enables heating of a fluid which does not admit the use of a metal material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to safe and reliable heating of a fluid which cannot use a metal material.

[0002]

2. Description of the Related Art In a conventional fluid heater in which a coil-shaped heating element is arranged on the outer surface of a resin tube, the circumference of the heating element is covered with a heat-shrinkable resin tube.

[0003]

In the conventional fluid heating heater in which a coil-shaped heating element is arranged on the outer surface of a resin tube, the circumference of the heating element is covered with a heat-shrinkable resin tube. The structure is shown in FIG. The purpose of using the heat-shrinkable resin tube is to electrically insulate the heating element and maintain the shape of the heating element. The structure in which the periphery of the heating element is covered with the heat-shrinkable resin tube has the following problems. B. The heat-shrinkable resin tube that covers the periphery of the heating element has a lengthwise dimension that is shortened by 15 to 20% with the passage of time of operation of the fluid heater, and at the same time, the heat-shrinkable resin tube is in close contact due to heat shrink The line spacing of the heating element is also narrowed by 15 to 20%, and the amount of heat generated per unit area is increased in the portion where the line spacing is narrowed, and the resin tube is melted and destroyed to cause fluid leakage. (B) When the temperature of the heating element becomes close to the melting point of the heat-shrinkable resin tube due to abnormal operation, the constraint force of the heat-shrinkable tube holding the shape of the coil-shaped heating element disappears, and the line spacing of the coil-shaped heating element becomes unclear. The amount of heat generated in the portion where the line spacing becomes extremely small becomes to change regularly, and melts and breaks the resin tube in a very short time, causing fluid leakage. The present invention eliminates such technical drawbacks of the prior art and provides a long-life fluid heater.

[0004]

DETAILED DESCRIPTION OF THE INVENTION FIG. 1 is a diagram of a new fluid heater. A coil-shaped heating element 2 is arranged on the outer surface of a resin tube 1 through which a liquid or gas flows, and the periphery thereof is covered with a thin and flexible resin tape 3 in multiple layers.

[0005]

The thin and flexible resin tape easily enters between the lines of the coil-shaped heating element and restrains the heating element from three directions, and reduces the change in the line spacing of the coil-shaped heating element due to heat load.

[0006]

EXAMPLE A concrete example will be described with reference to FIG. 3. A fluororesin PFA tube 4 having a diameter of 16 mm has a diameter of 1 mm.
A coiled nichrome wire with a wire spacing of 3 mm is attached so as to be in close contact with the outer surface of the tube, and the circumference is 15 mm wide and 0.1 mm thick.
While applying a slight tensile force to the fluororesin PTFE unfired tape of, the coiled nichrome wire and the fluororesin PFA tube are wound so as to be in close contact with each other. The number of layers was four. Fluorine resin PTFE unbaked tape has a melting temperature of 3
At 27 ° C, the distance between the coiled nichrome wires is maintained well up to that temperature.

[0007]

According to the present invention, it is possible to eliminate the melt damage of the fluororesin PFA tube caused by the partial overheating caused by the short distance between the coiled nichrome wires and the resulting fluid leakage. I can.

[Brief description of drawings]

FIG. 1 shows the structure of the invention.

FIG. 2 shows the structure of a conventional fluid heater.

FIG. 3 shows an embodiment of the invention.

[Explanation of symbols]

 1: Resin tube 2: Coil-shaped heating element 3: Thin and flexible resin tape 4: Fluororesin PFA tube 5: Coiled nichrome wire 6: Fluororesin PTFE unbaked tape

Claims (1)

[Claims] 1. A fluid having a structure in which a coil-shaped heating element (2) is arranged on the outer surface of a resin tube (1) through which a liquid or gas flows, and the periphery is covered with a thin and flexible resin tape (3) in multiple layers. Heating heater.