JPS5887792A - Heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric heating element that emits far infrared rays, particularly a fast heating type heating element.

Conventionally, there have been heating elements that emit infrared rays, particularly in the far infrared region, from a low-temperature radiator and are used for drying, cooking, heating, etc. These heating elements require several tens of seconds at the earliest, and several tens of minutes at the latest, from the time they start heating until they reach a temperature suitable for use.

However, in cases where the heating process is completed in a very short time, such as in a toaster oven, constant N''l for a close-up camera, or for heating a toilet, preheating the heating element in advance is a waste of energy. It is also a waste of time.Thus, for such purposes, there is a need for a heating element that is as stiff as possible to reach the required temperature and has a low response.

The present invention was invented in response to these demands, and is a heating element that uses electrical energy to emit radiation in the infrared region, particularly in the far infrared region, with a response time of several seconds and which reaches a usable temperature very quickly after turning on the switch. The purpose is to provide

The details will be explained below.

In a heating element that emits far-infrared rays, the total surface temperature of its radiation surface is usually maintained within a range of about 100°C to about 600°C.

A radiation surface kept at a high temperature emits gray radiation according to the wavelength band and emissivity depending on the temperature of the surface.

The problem is how to create a heating element with a radiation surface with good emissivity, and how to quickly raise the temperature of it.

FIG. 1 is a simplified diagram of the structure of a heating element showing an embodiment of the present invention.

In FIG. 1, 1 is a heating element, 2 is a heating element, 3 is a radiator, and 4 is a support electrode.

Since the far-infrared ray radiation surface has a low temperature, the radiant energy per unit area is much lower than that of a normal ρ tungsten lamp or an infrared lamp filament. For example, the radiation amount of the radiation surface near 100℃ is "-IW/cJ, 6
Since it is about 5 W/- at o □°C, the radiation surface must be wide for normal applications that require a total radiation of several hundred W or several kilowatts. On the other hand, in order to raise the temperature quickly, the heat capacity of the heating element must be small.

Metal foil is used for the heating element 2 of the heating element 1 of the water spraying invention so that the surface area is large despite its small heat capacity. Its thickness is 19 or less, and usually Fio, l+++s or less is used.

Since the surface of an unrusted metal has a low emissivity and is unsuitable as a far-infrared heating element, a thin radiator 3 with a high emissivity is formed on the surface of this metal foil. Since the radiator 6 must withstand heat at a temperature of about 600 to 700°C, an inorganic material is usually selected. Materials that have a good far-infrared emissivity, can withstand high heat, and are compatible with metals are selected, such as glass, enamel glazes, glazes used for ceramics, and heat-resistant paints containing a large amount of 5IO2, etc. is suitable.

The thickness of the radiator 3 is selected between o, o1 and o1.

If you want to make the temperature several hundred degrees in a few seconds, the thickness of the radiator filter should be about 2 m or less. Also, since the radiator 3 repeatedly heats up and cools rapidly, it is not preferable to make it too thick for that reason, and it is recommended to choose one with an expansion coefficient similar to that of the metal foil used for the heating element 2 due to temperature. Looks good.

The radiator 3 is formed by, for example, being baked at a high temperature or bonded to the heating element 2 with an adhesive.

Iron, Nichrome, etc. are suitable for the metal foil used for the heating element 2.

The heating element 1 is supported by a support electrode 4 and suspended in the air. In this case, if the radiator 6 is not attached to both sides of the heating element 2, it is advisable to place a metal reflector and a thermal insulator on the side without the radiator 6 close to it but not touching it. In order to obtain a fast response, under no circumstances should any object other than the radiator directly touch the heating element 2 over a large area.

FIG. 2 is a plan view showing an example of the structure of the heating element.

In FIG. 2, 5 is a plurality of notches provided in the metal foil.

The heating element 2 is machined from a single piece of metal foil by making cuts shown by width a to form a long strip-shaped electrical path shown by width a. The current to generate heat flows in the direction of the arrow. The cut 5 is necessary when making a heat generating element of several hundred W at OOv due to the resistivity of pure nickel, pure iron, etc., as the metal foil.

If one tried to obtain the required resistance with one nickel foil without notches, the thickness would become too thin to be practical.

It is preferable that the width of the cut is sufficiently narrower than the width a. This is because the thickness of the radiator B is relatively thin, and the heat conduction in the direction perpendicular to the radiation surface is good, but the heat conduction in the direction parallel to the surface is poor, so if the width of the cut part is wide, the radiation surface of that part This is because the cut portion cannot receive sufficient heat from the heating element, and the cut portion no longer functions as a radiation surface, resulting in a decrease in radiation efficiency per unit area of the radiation surface.

The cut-out portion 5 also serves to support the radiator 3.

FIG. 5 is a longitudinal cross-sectional view of a heating element constructed from the heating elements shown in FIG. 2.

In this embodiment, as shown in FIG. 5, the radiator loop extends behind the heating element 2 through the notch 50, which helps in integrating the radiator 6 and the heating element 2. There is. As mentioned above, the radiator 6 is thin and heats up rapidly.
Repeated rapid cooling can easily cause cracks and peel off of the heating element 2, so the cut 5 is
By creating a structure in which the heating element 2 is held all the way through, it is possible to prevent the radiator B from peeling off.

When emitting radiation from both sides of the heating element 2, that is, when forming radiation surfaces on the top and bottom of the heating element 2 in FIG. It is useful for

Heat generating element A ~ If the density of the notches 5 is small or there is no total heat due to the resistivity of the material used and the power used, make small holes in various parts of the heat generating element and make the notches 5 in Figure 3. By applying the same action, the radiator 5 becomes stronger.

FIG. 4 shows a heating element 2 with holes drilled for this purpose. In FIG. 4, (a) is a case with no notches, ('b) is a case with few notches, and 6 is a hole. The shape of the hole is the 4th
It is desirable to make it elongated parallel to the direction of current flow as shown in the figure. There is no problem with a round hole, but a hole of such a size that the width of the metal foil becomes narrower due to the hole and the resistance of that part becomes extremely higher than other parts is not appropriate1. , if the area is the same, it is better to make it long and thin parallel to the direction of the current.

As described above, the heating element of the present invention, in which an inorganic material with good emissivity is baked onto the heating element made of metal foil to form a radiation surface that can be supported in the air without touching other objects, can achieve the following effects: Many excellent effects can be obtained such as 1. Also, by providing narrow cuts or holes in the metal foil of the heating element, the strength of the radiation surface is increased and the effectiveness is further increased.

(1) A heating element with very fast response can be obtained.

(2) A far-infrared heating element having a strong heating effect per unit occupied area can be obtained.

(3) It is possible to easily make a heater, etc. that is lightweight and easy to carry.

(4) It is possible to obtain an energy-saving heater that heats only when necessary and for a necessary time. There is no need to preheat, and heating does not continue even after the switch is turned off.

(5) A far-infrared heater with less risk of fire or burns can be obtained.

(6) A durable heating element that can withstand rapid heating and cooling can be obtained.

According to the present invention, it is possible to obtain a convenient and easy-to-use heating element that is useful for energy saving and has many effects, and has many uses in T-collection, household heaters, etc., and its economical effects are enormous. be.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a simplified structural diagram showing an embodiment of the present invention, Fig. 2 is a plan view showing an embodiment of a heating element, and Fig. 6 is the invention using the 21st YI heating element. FIG. 4(a) is a longitudinal sectional view showing another embodiment of the present invention; FIG. 4(b) is a plan view showing an embodiment of the heating element having holes and notches. 1. Heating element, 2. Heating element, 6. Radiating body, 5.
・Notch, 6...hole. Patent applicant Kokusai Technological Development Co., Ltd. “Figure 2

Claims (3)

[Claims] (1) It is characterized by consisting of a heating element made of metal foil that generates heat by electric energy, and a radiator made of a heat-resistant material that is in close contact with the heating element and has a high far-infrared emissivity. heating element. (2) The heating element according to claim 1, wherein the heating element is constructed by making a narrow cut in a metal foil. (3) The heating element according to claim 1, wherein the heating element is constructed by making a plurality of holes in a metal foil.