JPS59123180A - 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 is not intended to include one or more sources of infrared radiation in the wavelength range of 0.8 to 5 microns and with a maximum at a wavelength of about 1.2 microns. Regarding heating device IC.

Heating devices with infrared radiation sources are patented in British Patents Nos. 1 and 2.
No. 7 3 0 2 3, in which one or more infrared radiation sources consisting of lamps with tungsten filaments are provided below a hot plate made of glass ceramic. A metal reflecting plate is provided below the radiation source to reflect the infrared rays radiated downward from the radiation source upward and transmit them through the hot plate. The metal reflector is made of polished and anodized aluminum and is shaped to reflect infrared radiation over an area that covers the area of the bottom of the cookware placed on top of the hot plate.

However, in such conventional heating devices,
Various problems arise due to the presence of metal reflectors. That is, although this reflector can be placed close to the infrared radiation source for ideal efficiency and can be constructed relatively shallowly, this reflector will not work unless it is provided with insulation that causes a large amount of heat to be lost. , the heat from the radiation source may melt or at least significantly distort or discolor. This problem can only be solved by moving the reflector away from the total radiation source or by not providing thermal insulation, which would reduce the efficiency of the reflector to an unacceptable level.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an efficient heating device which has a faster operating time than gas-based heating devices while retaining its inherent cleanliness characteristics.

The invention provides a heating device in which at least one infrared radiation source is provided below a support means for supporting a cooking utensil containing food to be heated by the infrared radiation source, comprising:
Provided below at least one infrared radiation source 1l-
) Jl, a heat insulating material layer, and means for reflecting infrared radiation emitted from at least one infrared radiation source as described above, the reflecting means being provided between the infrared radiation source and the main part of the heat insulating material layer. It is being

Embodiments of the present invention will be described in detail below with reference to the drawings.

Referring to FIG. 1, for example, [Microtherm j (
A layer of insulation 2 made of microporous material known as Microtherm® is attached. The tray-shaped body 1 is provided with two flanges 3, 4 on opposite edges thereof, each flange 3, 4 having a bent portion 5,
I have 6.

A plurality of lamps, one of which is an infrared radiation source, designated by the reference numeral 7, are placed in the insulation layer 2'', and these lamps 7 are connected to both ends of the lamps. are supported by flanges 3 and 4.

A molding 8 of ceramic fibers is mounted on the tray 1 and fitted around the ends of the lamp 7, serving as a suitable hanging for the lamp holder.

Each lamp consists of a quartz tube halogen lamp with seven tungsten filaments (not shown), and a suitable example is described in British Patent Application No. 8308103 filed by THORN EMI pie.

Each end of each lamp 7 has a pinch seal with a tag-type connector connected to its filament-filled end.
H-seals) (not shown) are provided with end caps 9 of molded ceramic surrounding each end cap 9, each tubular lamp having a flange 3, 4 .
Part 1 5. A locating tab 10 is provided for easy insertion into the gap formed by 61/17.

The tray 1 and the flange 3.4 can be made of metal material, and the gap into which the end cap 9 is inserted is such that the lamp 7 is not destroyed by thermal expansion of the tray 1 and the flange 3.4. There is enough leeway as in (
- and, on the other hand, provide sufficient support for the electrical connection with the lamp 7 tag type connector. The above gap also extends from the pinch seal of lamp 7 to flange 3.
It also serves to maintain the operating temperature at an appropriate temperature by ensuring good heat conduction to the 4.degree. Heat is also arranged to be conducted via the electrical connections at both ends of the lamp 7.

If further cooling of the pinch seal is required, the heat sinking and cooling techniques described in British Patent Application Nos. 8314.451, 8316304 and 8318457, or any suitable conventional method may be applied.

The ceramic fiber molding 8 supporting the lamp 7 has sufficient flexibility to allow movement during thermal expansion and contraction of the tray 1 and flanges 3, 4.

The lamps 7, which are shown in FIG. 1 and can be four infrared emitters, are preferably placed under a glass-ceramic layer, which in this example is made from Corning Black Kunktonop 9632. It is a standard worktop (worktol)
) A thin cooking table comparable to the depth of (cool <
ing hob).

In order to limit the operating temperature of the glass-ceramic layer, a thermal limiter 11 consisting of a bimetallic rod actuating a microswitch 12 is provided between the lamp 7 and the insulation layer 2, this thermal limiter] 1 is operated by the deformation of the bimetallic rod by the heat dissipated from the lamp 7. When the temperature reaches the threshold value, one end of the bimetallic rod actuates the microswitch 12 to deform the bimetallic rod. When adjusting the heat limiter 11, it is necessary to take into account the effects of infrared radiation, which can cause changes in the reading of the furniture.

2 and 6, in which corresponding parts are given the same reference numerals as in FIG. 1, are cross-sectional views taken along the X-X line and the Z-2 line in FIG. In particular, it shows not only the thin overall structure but also the structure of the basin-shaped body 1 and the entocasop 9.

The glass-ceramic layer described above has a transmission characteristic that matches the frequency (C) of the red IA line, so it has an ideal transmission t1, 〒
It has sex.

This glass-ceramic layer substantially absorbs radiation at wavelengths less than 0.6 microns. However, visible light with longer wavelengths, such as red light, is transmitted.

-1- The heating device described above has the advantage that the nominal energy load per unit heat generating surface is high. The nominal energy load per unit heating surface of a standard heating device is only about 6 W/cA, but in this example, the energy radiation characteristics of the lamp and the energy passing characteristics of the hot plate are matched. , the energy load is as high as 8W/c4.

FIG. 4 shows a suitable radiation transmission characteristic curve of a glass-ceramic plate with a thickness of about 4 mm, in which the maximum value in the wavelength band of the infrared radiation emitted by the infrared radiation source according to the invention lies at a wavelength of about 1.5 mm. Horizontal 1 at the 2 micron position (dashed line A perpendicular to b)
1, and the transmittance at that wavelength is about 80 factors.

To control the heating device according to the invention, a multi-pole, preferably 7-pole switching device is used, with a series-parallel connection of four lamps with 500 W filaments, approximately 21
Switching is done within the range from W to 147 Wt.

FIG. 5 shows six combinations of four lamps with filaments of 50 (1 W) (one of which is not shown at 7 in FIG. 1), allowing the user to select six positions. A selectable rotary knob (not shown) allows all desired outputs to be selected by switching the switching means.
/II The percentage of each output relative to the total output of 2000W is also shown.

diodes in the lower two of the above six combinations]:
3 is used, but this position is not only suitable for the so-called simmering condition, but also has the aesthetic effect that the light from the filament looks beautiful through the entire glass ceramic layer.

The diode used in the switching means in a heating device using a hot plate serves to half-wave rectify the alternating current obtained from the line power supply.

In some situations, it has been observed that harmonic disturbances occur on the AC line at switch position A31F. In order to alleviate this problem, two diodes connected in parallel with opposite polarities are used in place of the diode 13, and this force can suppress the second and fourth higher waves.

Furthermore, the switching means allow different uses of the infrared lamp and allow the heating device to be operated with lower power.

Even with a phase control means using a diac, triac, etc., an output of about 200 W or less can be obtained according to international standards.

However, for higher power operating settings, one or more continuously-energized lamps may be used to reduce the overall flicker effect in the lamps.
Itemoyoi for one-person space control using amp).

For example, two burst fire condolences 0
Lamp (burst-fire controlled)
The advantage of using two continuously-excited lamps with lamps is that two burst-fire condorature lamps operate at a higher frequency than with four such lamps.

The heat limiter 11 shown in FIGS. 1 and 2 maintains the maximum temperature at the bottom surface of the glass-ceramic hot plate below about 700°C. Thermal limiter 11 must be adjusted to eliminate malfunction of microswitch 12, thereby cutting off the power supply to the lamp.

The use of a heat limiter in such an apparatus has the advantage that cooking utensils made of any material can be used.

However, when using the heating device according to the invention, the cooking utensil exhibits different characteristics than when using other heating devices. That is, as the bottom of the cookware is heated by the infrared radiation, the deformed cookware absorbs the heat radiation and the heat is transferred to other places by maintaining good contact between the bottom of the cookware and the heating area. It has the advantage of operating more efficiently than the electric cooking device 1'1'. If the cooker has an uneven and highly reflective bottom 41, the infrared rays will be reflected by the hot plate side 1, and the cooker will operate with lower efficiency than if it were a cooker. At this point, the operating temperature becomes high (71, I/ζ31), and the heat limiter operates. Under these conditions, the heat limiter turns the lamp on and off to maintain a moderate temperature of the glass-ceramic layer, so that it is not visually apparent that the cookware is operating in inefficient conditions.

It is possible to have two insulation layers with a thickness of about 12 mm.
It is preferable that t, L <'1, and grooves approximately the diameter of each lamp are formed at appropriate positions on the surface.

Using a quartz tube...logen lamp as an infrared, Y-ray radiation source not only has the advantage of fast operation with a heating device, but also has the color temperature of the filament of 2400°K.
Filament I.
Another advantage is that it has a long lifespan.

FIG. 6 is a schematic diagram of a lamp 14 and a glass-ceramic layer 5, in which a coating 16 made of metal oxide or other reflective material is applied to the lower part l/C of the lamp 4. ing. The filament 17 of the lamp 14 is located at a point 4 on the coating 16, and infrared rays (d) emitted downward from the filament 17 are reflected by the coating 16 and directed toward the glass-ceramic layer 15.

Instead of or in addition to the reflective coating applied to each lamp, the surface of the heat insulating material layer may also be provided with a reflective coating such as a metal oxide or a surface reflective layer. By providing such a reflective layer between the lamp and the main part of the insulation layer, the insulation layer substantially blocks infrared radiation.

The heat insulating layer 2 made of microporous material is used together with the reflective coating of the lamp, or even with the reflective layer on the surface of the heat insulating layer 2, thereby reducing the direct radiation component from the lamp and the reflection from the reflective layer. This has the advantage that both components pass through the glass-ceramic layer, and in addition, the insulation layer or the reflective layer thereon exhibits good reflectivity at higher frequencies12.
, the infrared absorption in the glass-ceramic layer is reduced, and higher frequency components are not transmitted through the glass-ceramic layer.

The cross-sectional shape of the portion of the lamp tube to which the reflective film is applied may not be completely circular but may be elliptical 17, and the filament 10 may be positioned at the focal point of the ellipse.

It is also possible to make the lamp tube a quartz tube or a glass ceramic, so that the lamp has an optical filter within its tube.

The lamp may be placed in a separate tube with optical filter properties. Instead of, or in addition to, providing an optical filter within the tube of the folding lamp, a separate optical filter may be used.

Visible light can also be blocked by using Corning 9618 type glass ceramic in the lamp tube along with an optical filter. In this case, the filter can be provided in the form of a coating on the glass-ceramic, or between the lamp and the glass-ceramic, or even on the quartz tube.

A conventional mechanical cam-actuated bimetallic switch may be used to set the amount of infrared radiation, making it cheaper and more reliable. Similarly, phase control means such as diac or triac may be used.

A feedback thermal control device may also be used, such as that disclosed in GB 2071969, which is based on "fiber optics".

The heating device according to the invention can be used with or without a glass-ceramic layer by supporting the cooking utensil 1 and using other support means to protect the lamp.

Moreover, instead of placing a cooking utensil on the heating device, the heating device itself can be configured as a cooking utensil.

In order to ensure the radiation of infrared heat to the food to be cooked, use may be made of glass-ceramic cookware which transmits infrared radiation directly to the food or with an infrared absorbing base.

The heat generating surface irradiated by the lamp in the heating device of the present invention is not limited to a circular shape, but can be configured in various shapes and dimensions such as a gravity shape or a rectangle. It can be annular, horseshoe-shaped, or concentric circles with both ends aligned, and a lamp with several taps may be used.

Both ends of the lamp may be connected with lead wires instead of the amplifier type tag connector 9.

The thermal limiter 1 may be placed in any position relative to the lamp, and may be placed above, below, or parallel to and on the same plane as the lamp. You can also place it perpendicular to the lamp.

This thermal limiter should be shielded from infrared radiation in order to be responsive to the temperature of the glass-ceramic layer. The shield may be formed from a suitable infrared reflective coating, such as a metal oxide coating, or the thermal limiter may be covered with ceramic fiber or other suitable material. Alternatively, the thermostat may be mounted within a layer of insulation shielded from infrared radiation.

In the heating device of the invention, a suitable position 1 is provided as a means for sensing and limiting the temperature of the glass-ceramic layer.
An electrical control system with one thermal sensor may be used. This sensor is of course shielded from infrared radiation in a manner similar to a bimetallic thermal limiter.

Further, a thermostat may be provided outside the tray-shaped body. The thermostat receives heat either directly from the tray or through a window that can sense the temperature within the tray and is adjusted to sense a temperature equal to the temperature of the desired glass-ceramic layer.

In addition, the infrared lamps are perpendicular to each other at the bottom of the glass-ceramic layer, as long as the amount of infrared light transmitted through the glass-ceramic layer is kept at a high level and the infrared radiation is fully distributed over the entire heating area of this glass-ceramic layer. It can take any horizontal position.

In order to ensure efficient operation as a heat insulating material layer, the heat insulating material layer may be required to have a certain thickness. Insulation materials manufactured by Co., Ltd., Wallaker, or Johns Manville may be used, or mineral wool, glass fibers, calcium silicate, ceramic fibers, or alumina fibers may be used.

By choosing a material of suitable strength to be self-retaining, this layer of insulation and a tray to support the lamp are also eliminated.

Even when a tray-shaped body is used, it can be made of plastic instead of metal.

A preferred embodiment of the invention operates at a color temperature of about 24,000. However, around 18,000 to 3
It is possible to operate at color temperatures in the range of 0.000°.

The heating device according to the present invention can be used in various applications such as microwave ovens, grills, broilers, toasters, etc.

Although the preferred embodiment of the heating device according to the invention has four heat sources under the glass-ceramic layer, it may be equipped with any number of heat sources, especially one with one heat source, although smaller It can be configured as follows.

The heating device according to the invention has a relatively lake-shaped configuration using infrared radiation, has a flat surface so that it can be easily cleaned and can be used with cooking utensils of any material. Not only that, but compared to conventional cooking devices that use gas as fuel, the response time is short and the cooking time is also shortened due to the efficiency.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an embodiment of the heating device according to the present invention, FIG. 2 is a sectional view taken along line XX in FIG. FIG. 4 is a curve diagram showing the radiation transmission characteristics of the glass ceramic plate applied to the heating device of the present invention, FIG. 5 is an explanatory diagram showing various combinations of filaments by switching means, and FIG. FIG. 2 is a schematic enlarged sectional view of the main parts of the heating device. ] in the figure is a tray-shaped body, 2 is a heat insulating layer, 3. /I is a flange, 7.14 is a lamp, 11 is a heat limiter, 12 is a microswitch, 1; 3 is a diode, 15 is a glass ceramic layer, 16 is a reflective coating, and 17 is a filament. Patent Applicant: Thorne MI Tomestic Appliances Limited Patent Attorney Toshihito Yamamoto 9th layer FTC, 5 FTC, 6 Continued from page 1 Priority claim @ March 24, 1983 ■ United Kingdom (GB
)■8308105 0 Inventor Graham Howlett Gutschild 3 Boatchinister Camelot Crescent, Hampsshire, United Kingdom

Claims (1)

[Scope of Claims] 1. A structure comprising at least one infrared radiation source, wherein the infrared radiation source is provided below a support means for supporting a cooking utensil containing food to be heated by the infrared radiation source. The heating device includes a heat insulating material layer provided below the at least one infrared radiation source, and means for reflecting infrared radiation emitted from the at least one infrared radiation source, and the infrared reflection means reflects the infrared radiation. A heating device, characterized in that it is provided between a source and a main part of the heat insulating material layer. 2. The heating device according to claim 1, wherein the heat insulating layer is made of a microporous material. 3. The heating device according to claim 1 or 2, characterized in that the at least one infrared radiation source comprises a tungsten filament/ζ tungsten halogen lamp enclosed in a quartz tube. Said device. 4. The heating device according to claim 3, wherein the infrared reflecting means comprises a metal oxide coating deposited on the lower surface of the quartz tube. 5. Any one of claims 1 to 4
A heating device as described above, characterized in that the support means consists of a glass ceramic layer extending above the infrared radiation source. 6. Any one of claims 1 to 5
2. The heating device according to claim 1, wherein the separate layer of heat insulating material is housed in a shallow tray-shaped body. 7. Any one of claims 1 to 6
In the heating device described in , a molding of ceramic fibers is fitted around the ends of the at least one infrared radiation source to form a flexible backing for the infrared radiation source. The device characterized in: 8. In the heating device described in any one of the ranges 1 to 7 of Patent M-1, the infrared radiation source is provided in multiple stages, and the entire output range of the infrared radiation source is set. A temperature regulating device comprising switching means for interconnecting the infrared radiation sources in frtr combinations is provided for this purpose. 9. The heating device according to claim 8, wherein the switching means comprises a diode connected to at least one of the combinations of infrared powder radiation sources in order to obtain a suitable simmering condition. The device characterized in that: 10. Claims 1 to 2! 7. A heating device according to claim 1, characterized in that a temperature adjustment device is provided for controlling the phase of the at least one infrared radiation source. 11. Heating device according to claim 10, characterized in that the temperature regulating device comprises a source for continuously supplying energy for the infrared radiation. 12. The heating device according to any one of claims 1 to 11, characterized in that it is provided with an optical filter that blocks unnecessary visible light. 13. The heating device according to any one of claims 1 to 12, characterized in that the heating device is provided with a heat limiter that prevents the maximum operating hot water temperature from being exceeded. Said device. 14. The heating device of claim 13, wherein the thermal limiter is shielded from infrared radiation so that the thermal limiter can accurately monitor the operating temperature. . 15. A cooking table comprising at least one heating device according to any one of claims 1 to 14. 16. The cooking table according to claim 15, wherein two or more heating devices are provided,
Each heating device is equipped with a diode as its switching means,
Device as described above, characterized in that the diode is connected with arbitrary polarity to ensure an evenly distributed load to the power supply.