JPH11135232A - Radiation heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation heating device which can protect a high- temperature radiator from mechanical damage at a low cost, improve optical attenuation characteristics, and decrease the dazzling action of light. SOLUTION: In a radiation heating device provide with a housing 10, at least one reflector 11 installed in the housing, an outlet 17 for a radiation OFTR, and a high-temperature radiator 15 related to the reflector, the high-temperature radiator 15, the reflector 11, the outlet 17 for the radiation OFTR are arranged so that all rays generated from the high-temperature radiator 15 pass through the outlet 17 for the radiation OFTR after reflecting at least once.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a radiant heater device comprising a housing, at least one reflector disposed in the housing, an outlet for a radiant OFTR, and a high temperature radiator associated with the reflector. Things.

[0002]

2. Description of the Related Art A high-temperature radiator has a temperature of about 2000 ° K to 2 ° C.
In consideration of the high temperature of 800 ° K, the operation is performed in a closed tubular envelope. That is, high temperature radiators cannot radiate heat without oxidation in normal atmosphere, for example, this is the case with kanthal radiators that reach up to about 1500 ° K. Such a tubular envelope is generally formed of quartz. Typical radiator materials are, for example, about 2000 ° K to 2800 °
The temperature of K is tungsten. An advantage of such a high-temperature radiator is that the higher the temperature, the more the same heating power can be obtained from a smaller burner size (smaller heater device). Another advantage of a smaller radiation source is that the focusing properties are improved and this results in an efficient radiation distribution (local limited radiant heating). However, this has the disadvantage of giving the impression that light is being emitted to the human eye from about 2000 ° K as the temperature increases. That is, the visible dazzling action increases to a degree that causes discomfort, giving anxiety that there is a risk of fire. About 20
Because of this glare effect starting at 00 ° K, it is generally essential to take measures to reduce the luminance component. Currently known devices are broadly classified by the following measures. That is, a. A quartz tube or other tubular envelope, such as a lamp bulb, is used to absorb radiation associated with the visible range. In this case, the energy density is limited to an allowable maximum temperature in consideration of a rising temperature load. b. Cover the device to absorb the visible range. This is the usual means used in halogen light cooking ranges. However, in this case, the transmission for thermal radiation is less than about 60%. c. Use a cut-off interference filter for the cover. However, this does not make it possible to achieve a thermal load state exceeding about 400 ° C. in practice. d. Use cut-off interference filters in lamp bulbs or quartz tubes (see, for example, US Pat. No. 4,588,9).
No. 23, “High Efficiency Tubular Heat Lamp”
s ").

[0003]

However, all of these solutions are technically established and form part of the prior art, but because of the temperature loading limitations of the light absorbing components. However, there is a drawback that the power density in the upward direction is limited, or that the cost for taking measures for performing optical attenuation is increased. Another problem is that the brightness of the radiation itself, which is directly visible to the eye, increases, even if the overall impression of light as perceived as light is unacceptably low due to the light attenuation means. I can say. This impression can only be improved by known additional means of reducing the brightness (for example, frosted glass lamps, refractive structures in covers or special hexagonal reflective grating structures). Finally, all high-temperature radiators without a robust cover have the disadvantage that they are mechanically vulnerable, for example, to mechanical influences or thermal shocks (splashes).

Accordingly, it is an object of the present invention to provide a radiant heater device capable of protecting a high-temperature radiator at low cost from mechanical damage, improving light attenuation characteristics, and reducing glare.

[0005]

In order to achieve this object, the present invention provides a radiant heater device of the type mentioned at the beginning, comprising a high-temperature radiator, a reflector and a radiant OFTR.
The arrangement of the outlet for the OFTR is such that all rays emanating from the hot radiator are reflected at least once before radiating the OFTR
And an exit configuration for exiting from the outlet. According to this configuration, all direct visual and direct glare effects on the high-temperature radiator are prevented. All rays reach the exit through at least the following reflections:
Such a configuration of the hot radiator means that the hot radiator is directly protected from mechanical damage or mechanical contact, meaning that there is no direct contact with any object such as, for example, a knitting needle. I do.

In a preferred embodiment of the invention: the reflector has a substantially semicircular cross section, projects forward in the lower region of the reflector, has an outlet for the radiating OFTR, and upper and lower boundary edges Providing a funnel-shaped part with an edge,-accommodating the hot radiator in a position corresponding to the upper area of the reflector, and-the outermost lower border edge when the connecting line connecting the hot radiator and the border edge is extended. Are arranged and arranged to abut on the inner or lower boundary edge.

[0007] The hot radiator in this embodiment optimally prevents the risk of objects falling on the radiator that could cause an explosion. It is difficult for the spray to reach the hot radiator.

Further, in a preferred embodiment of the present invention,
The reflector is bent several times to form a bent edge. According to this embodiment, the rays can be optimized for the exit.

Further, in another preferred embodiment of the present invention, the reflector is made of pure aluminum. According to this configuration, a reflectance of 90% or more can be obtained in a heat lamp that emits the maximum radiation in a wavelength range of about 1 μm to 2.5 μm. However, pure aluminum also reflects about 90% of the visible light portion, causing unpleasant glare in such systems.

Further, in a preferred embodiment of the present invention,
At least a part of the reflector made of pure aluminum is covered with a black oxide layer. According to this embodiment, this glare effect can be drastically reduced without a distinct reduction in infrared reflections in thermal radiation above 1 μm wavelength. Such a black oxide layer shows high selectivity. This means that the light is considerably attenuated and that the absorption in the radiation region adjacent to the infrared region is extremely small. According to this embodiment, the temperature rise of the reflector material remains within a manageable range.

Further, in another embodiment of the present invention, the reflectance of the oxide film layer is set to a reflectance of 10% or less over a wavelength range of about 0.4 μm to 0.7 μm, and a reflectance of about 1 μm to 2.0 μm.
An oxide film layer is applied so as to have a reflectance of 90% or more in a wavelength range of 5 μm. According to this embodiment, the oxide layer exhibits particularly high selectivity. The oxide film material thus formed has a main radiation range of the high-temperature radiator (1 μm to 2.5 μm).
m, a high reflection characteristic in the visible wavelength range (0.
(4 μm to 0.7 μm), showing low reflection characteristics (typically 7% for a black oxide film layer). In this way, about 15 times as much light attenuation is obtained in one reflection, and most of the thermal radiation is reflected without attenuation. Such a black oxide coating is very convenient to form a reflector that significantly reduces the amount of light, and still allows for thermal radiation.

In the final fine adjustment of the reflector structure,
It is important to minimize reflector heating. In this case, pure aluminum is durable at temperatures as high as about 400 ° C., and the oxide layer having high selectivity is about 200 ° C.
Shows durability at temperatures below ° C. A structure in which each light ray generated from the high-temperature radiator according to claim 7 is reflected at least once by the black oxide film layer, and
In combination with the described arrangement in which the reflector part in the immediate vicinity of the high-temperature radiator is made of pure aluminum without an oxide coating, an effect is obtained with a lower maximum thermal load on the reflector despite sufficient light attenuation. That is, it is for disposing a black oxide film material having higher heat absorption characteristics in a region having a low energy density.

Further, in another embodiment of the present invention, the thickness of the oxide film layer is in a range between about 10 μm and about 20 μm. According to this embodiment, aluminum can be provided with a relatively thick mechanical protection layer. This relatively thick protective layer still exhibits the above-mentioned good heat reflection properties in the wavelength range up to about 2.5 μm.
Such an oxide layer thickness of 10 μm or more is about 2.8.
Higher thermal absorptivity is obtained only for wavelengths of μm (water absorption band) and wavelengths of 7 μm or more (intrinsic absorption of aluminum oxide).

When it is not necessary for the oxide film material to satisfy the mechanical protection function, the thickness of the oxide film layer can be set to 10 μm or less. Absorption reductions in the two ranges mentioned above are thus obtained. A thin oxide layer of less than 10 μm is used, for example, when the radiant heater is protected by an exit grid and mechanical surface hardening of the reflector material is not required. 10μ
m or less of such a layer can be applied more quickly than a layer of normal thickness of 10 μm to 20 μm. As a result, the heat absorption at 2.8 μm and 7 μm or more can be reduced, and the temperature rise of the reflector material can be reduced.

Other suitable means of reducing the temperature of the reflector material include configuring the reflector to reduce double and multiple reflections to a minimum number, or venting the reflector in close proximity to the hot radiator. This can be achieved by providing a slot. By providing the ventilation slot as described in claim 12, hot air can escape upward from the vicinity of the high-temperature radiator without adversely affecting radiation reflection.

Further, the temperature of the reflector material can also be reduced by increasing the heat dissipation behind the reflector. This can enhance radiation in the direction of other internal housing parts and supplement other usual cooling.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a preferred embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a heater device having a housing 10 and a reflector 11 arranged in the housing, the reflector 11 having two reflector portions 13, 14 separated from each other by a ventilation slot 12. A hot radiator 15 is provided adjacent to the upper reflector portion 13. The reflector 11 having the two parts 13, 14 is substantially semicircular in cross section and is provided with a funnel 16 in the lower region, in which an outlet OFTR 17 projects forward, and this outlet OFTR 17 is covered by a grid 18. Reference numeral 19 indicates a control panel.

The reflectors 13 and 14 are provided with bending edges 13a and 14a so as to obtain a required radiation distribution. Light rays 20a and 20b generated from the high temperature radiator are
It is reflected at least once before exiting the FTR 17.
In order to achieve this, the upper inner boundary edge 16a of the funnel 16 is configured as follows. That is, when the connecting line connecting the high-temperature radiator 15 and the boundary edge 16a is extended, the connection line is made to abut the funnel-shaped portion 16 inside or on the outermost lower boundary edge 16b. The reflector 11 is made of pure aluminum. Upper reflector 13 in which high-temperature radiator 15 is present in the vicinity
Is subjected to either a gloss finish or an oxide film formation process, while the lower reflector 14 is always provided with an oxide film layer 14b in order to prevent glare. If the upper reflector portion 13 is not treated with an oxide film, light rays 20a in the visible range are also reflected, but this is not so important due to multiple reflection. On the other hand, most of the light rays 20b reflected by the reflector portion 14 are reflected only once. Therefore, the reflector portion 14 is always provided with the oxide film layer 14b in order to prevent glare. In principle, a thin oxide layer provided on pure aluminum, which is a reflector material, allows a degree of freedom in the visible range of the light rays for applying eye-catching colors. That is, it is not always necessary to make the color black, but for example, it can be made dark red. Furthermore, the reflector part which can be seen from the outside can be hammered to further reduce the impression that the rest of the visible light part is dazzling to the person seeing from the outside.

The reflector 11 according to the invention can provide a favorable radiation distribution of the reflector material. That is, a portion made of pure aluminum alone can be used at a position where the power density becomes the highest temperature adjacent to the high-temperature radiator 15, and a portion provided with the oxide film material is mainly used in a region where the power density becomes low.

[0021]

According to the present invention, the manufacture of the radiation heater device can be reduced. That is, standard components with simple constructions, such as standard heat radiators, can be used, and thin oxide layers are easier to apply than standard hot oxide layers.

FIG. 2 shows the reflectance R% as a function of the wavelength λ / μm of the black oxide layer used in the part of the pure reflector according to the invention. It exhibits high reflectivity in the main radiation range of the high-temperature radiator (wavelength is about 1λ / μm to 2.5 μm) and low reflectivity in the visible wavelength range (about 0.4λ / μm to 0.7 μm). That is, the light attenuation characteristics are improved.

[Brief description of the drawings]

FIG. 1 is a diagrammatic illustration of an embodiment of a heater device according to the present invention.

FIG. 2 is a graph showing the relationship between the radiation range and the reflectance of the heater device according to the present invention.

[Explanation of symbols]

 10 Housing 11 Reflector 12 Slot 13, 14 Reflector part 13a, 14a Bending edge 15 Hot radiator 16 Funnel 16a Upper inner boundary edge 16b Lower boundary edge 17 Outlet OFTR 18 Grid 19 Control panel 20a, 20b Light beam

 ──────────────────────────────────────────────────の Continuation of the front page (71) Applicant 590000248 Groenewoodseweg 1, 5621 BA Eindhoven, The Netherlands (72) Inventor Klaus Klinkenberg, Germany 52080 Aachen Waldstrasse 39

Claims (12)

[Claims] 1. A housing (10), at least one reflector (11) disposed in the housing,
In a radiant heater arrangement comprising an outlet (17) for a radiant OFTR and a hot radiator (15) associated with said reflector, an outlet (17) for a hot radiator (15), a reflector (11) and a radiant OFTR. ), Wherein all the light rays emanating from the hot radiator (15) are reflected at least once before exiting the outlet (17) for the radiating OFTR. 2. The reflector (11) has a substantially semicircular cross section, and projects downwardly from a lower region of the reflector,
An outlet (17) for the radiant OFTR, and a funnel (1) having upper and lower border edges (16a, 16b).
6) provided:-the hot radiator (15) is accommodated in a position corresponding to the upper area of the reflector (11); and-the connecting line connecting the hot radiator (15) and the border edge (16a) is extended; The radiant heater device according to claim 1, wherein the radiant heater device is arranged and arranged so as to abut on the inside of the outermost lower boundary edge or on the lower boundary edge. 3. The radiant heater device according to claim 1, wherein the reflector is bent several times to form bent edges. 4. The radiant heater device according to claim 1, wherein the reflector is formed of pure aluminum. 5. The radiant heater device according to claim 4, wherein at least a part of the reflector formed of pure aluminum is covered with a black oxide film layer (14b). 6. The oxide film layer has a reflectance of about 0.4 μm to about 0.4 μm.
6. The radiant heater device according to claim 5, wherein an oxide coating layer is provided so as to have a reflectance of 10% or less over a wavelength range of 0.7 [mu] m and to have a reflectance of 90% or more in a wavelength range of about 1 [mu] m to 2.5 [mu] m. 7. The radiant heater device according to claim 5, wherein each light beam generated from the high-temperature radiator (15) is reflected at least once by the black oxide film layer (14b). 8. The radiant heater device according to claim 5, wherein the reflector portion (13) in the immediate vicinity of the high-temperature radiator (15) is formed of pure aluminum having no oxide film. 9. The oxide layer (14b) has a thickness of about 1
6. A thickness in the range between 0 μm and about 20 μm.
The radiant heater device as described in the above. 10. The oxide layer (14b) has a thickness of 1
The radiant heater device according to claim 5, wherein the radiant heater device is set to 0 µm or less. 11. The radiant heater device according to claim 1, wherein the reflector is configured to reduce double and multiple reflections to a minimum number. 12. The radiant heater device according to claim 1, wherein a ventilation slot (12) is provided in the reflector (11) very near the high-temperature radiator (15).