DE1808977A1 - Infrared heat emitter - Google Patents

Description

Patent AttorneyB
Oipl. Ing.Walter Meissner

Dipl. Ing. Herbert Tischer Munich, November 14, 1968 Munich office
Munich 2, valley 71 ^cr

THE BAEBEE MANUFACTUEING COMPANY, Ohio (7 "St, A.)

Infrared heat radiates

The invention relates to an infrared heat radiator with an electrical heating element arranged in a housing and an eeflector

The object of the invention is to improve the usable radiant heat output of such an infrared heat emitter, in particular, a high proportion of the emitted infrared * radiation should lie in a certain wavelength range

This object is achieved according to the invention in that an infrared radiation plate is provided below or in front of the heating element, the upper surface of which has an absorption capacity of at least 0.86 at a temperature of 482 ° C. and the lower surface of which has an emissivity of at least 0.86 at a temperature of 482 ° G, the lower surface having a dimension of at least 0.1 square meters and emitting the main part of the radiation in the wavelength range from 3 _f o to 5, o microns, and that the reflector has a reflector surface of at least 0.1 square meters qm has »

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In practicing the invention, the Radiant panel on, a temperature of about 4-3o to 51o ° O, preferably 4-54 ° to 482 ° G-, through that of the heating element The heat generated and reflected by the reflector is heated or held at this temperature.

The infrared radiation output of such an infrared heat emitter is at least 10 to 15 % higher than that of the known infrared heat drainers, where the emission takes place at temperatures above 815 ° 0, at which temperatures the highest percentage of infrared radiation lies in a wavelength range of 2 to 3 microns

The drawing illustrates two exemplary embodiments of the invention · It shows

Fig »1 is a plan view of an infrared heat radiator, partially broken open;

Fig. 2 is a cross-section along the line "2-2 in Pig, 1}

FIG. 3 shows a cross section like FIG. 2 another embodiment

The heater A shown in FIG · 1 and 2, a schusseiförmiges metal housing 1, a © infrared beam "plate 2 _t a resistive heating element 3 ₉ a sealed cap 4 for the electrical connection and a reflector surface 5 on the -Innenseite of the housing 1 to reflect the heat to the radiant panel 2

The housing 1 and the radiant panel 2 have Randflanach® 7 and 8, between which a ring seal 9 made of asbestos is arranged is »the circular holes 1o in the gasket 9

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align with corresponding holes 11 of the edge flanges 7 and 8, so that the radiant panel 2 can be rigidly connected to the housing 1 by means of screws 12

3Öie radiant panel 2 has a flat, horizontally extending middle part 13 and a rounded side part. Insulation is preferably provided between the reflector 5 and the cap 4 in order to protect the connecting cable. This insulation is designed here in the form of a circular insulator 16 which is inserted into a central circular opening in the housing 1 coaxially to the edge flange 7 of the cap 4 is inserted, which is fastened to the housing 1 by means of screws 28 «The power supply for the heating element 3 takes place by means of the cable 18, which is led into the cap 4 and contains two conductors 19 and 2o consisting of a number of insulated wires, which are connected by means of terminals 21 and 22 are connected to the vertical ends 23 of the heating element 3 « DIt voltage of the supplied alternating current is usually 2o8 to 24o volts»

Starting from the unheated ends 23, the heating element 3 initially has straight, radial and horizontal ends ! Dents 24, which extend to the (dents 25, which Form the inner circle of the heating element 3. Two rounded intermediate parts 26 connect the dent 25 with the circular one Outer part 27 of the heating element 3 ″ Such flat coil-like Coiled heating element are generally known although the heating element 3 shown only has two concentric circular arcs has three or more arcs would also lead to the best results «

According to the present invention, the usable radiant heat output of an electric infrared heat radiator becomes dl considerably increased with resistance heating element and reflector *

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A common electrical resistance heater has a Heating element that has a temperature of approximately 819 "to 917 ° O and emits infrared radiation, the highest part of which is in the wavelength range from 2, ο to 3, ο microns lies. The electric heater according to the invention is similar in that it has a reflector and a heating element which is also heated to a very high (temperature, but it is very different than it has a much higher efficiency and most of the emitted infrared radiation is in the wavelength range from 3. o to 5 »ο microns.

The implementation of the invention requires that the heating element 3 is kept at a temperature of about 76> o ° o to 88o ° O and an infrared radiant panel 2 with a large surface and at a short distance from the heating element 3 is arranged so that the lower, more distant surface of the radiating plate to a suitable temperature comes * This temperature should be about 43o be up 5I0 ⁰ 0, although some advantages of the invention even at such a low temperature such as 37o ° 0 or a temperature as high as 5 ^ 0 are obtained ° O. The upper and lower surface of the radiant panel 2 must be at least 0.1 square meters, and the material of the radiant panel 2 must have an emissivity and absorption capacity of at least 0.86 at 482 ° G and the material must also be such that at this temperature the main part of the infrared radiation is in the desired wavelength range of 3, o to 5 »o microns · A glazed porcelain or the like is preferably used as such material, which has an emissivity and an absorption capacity of at least 0.9 to 482 ° O ·

If necessary, the space enclosed by the housing Λ and the radiant panel 2, sealed to the outside, can be partially evacuated and at a pressure below the atmospheric pressure

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pressure to be kept to heat transfer by convection to a minimum · The sealed space can • also be filled with an inert gas, for example nitrogen or argon, or a gas with a low thermal conductivity.

A preferred embodiment of the infrared heat radiator according to the invention is shown in FIG. This radiant heater A1 essentially corresponds to the radiant heater A described, but its housing 1a is designed to be deeper and a reflector 5o is provided as a special part in the housing 1a.The housing 1a is bowl-shaped and its shape corresponds to the shape of the radiant panel 2 »^ ie side wall 3o of the casing 1a is formed in accordance with generally the side wall of the housing 1 and provided with a Hingflansch 7a similar to the annular flange 7, however, has the side wall for receiving the reflector 5o and to form an insulating air space between the reflector 5o and Housing 1a has a greater axial height

The housing 1a, like the housing 1, also has a flat middle part 31, which by means of support tubes 5I or the like « is hung from the ceiling of a room or on another supporting element. This support tubes 5I extend at illustrated embodiment into the housing 1a and form here vertical holding parts 32 »

The reflector 5o is etarr on the housing 1a or the Radiant panel 2 attached in any way. If the Edge flange 7a from the edge of the reflector 50 in a vertical position Direction away, the reflector is preferably carried by the housing 1a * This is the example shown caused by the holding parts 32, which at the lower end are provided with internal threads so that the retaining screws 33 can be screwed in. · Hold these retaining screws 33 the circular reflector 50 coaxial with the radiant panel 2,

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aligned with the heating element 3 and with the flat central parts 13 and 31. The rim of the reflector is preferably 5o on the side wall 3o of the case 1a or on ^a peripheral flange 7 thereof, so that a closed air space is formed above the reflector.

The reflector 5o has a reflector surface 5a corresponding to the reflector surface 5 and is at least 2.5 cm from the central part 31 of the housing 1a, so that an insulating air space 35 is formed above the reflector $ o , whereby the temperature of the housing 1a is reduced during operation · The reflector 5o also has a layer 16b of heat-insulating material on its back, for example glass wool or "Ityrowool" · The thickness of the insulating layer is preferably at least 0.1 cm or similar Insulator 16a and are firmly connected to the reflector 5o by insulating pieces 34 or they are carried by it.

The construction and arrangement of the infrared radiant panel are critical for the implementation of the invention. The lower surface of the radiant panel 2 should be heated to a temperature of 37o ° to 54-0 ° 0 when the heating element 3 is at a temperature of 7 ^ 0 ° 0 to 86o ° 0. Best results are obtained when the lower surface of the radiating plate 2 is at a temperature of 43o ° 0 to 5I0 ⁰ C · TIIE upper surface of the radiating plate 2 is heated by radiation and preferably has an absorbency of at least about o, 9 at 482 ° , 0 "The lower surface of the radiant panel 2 must have an emissivity (d, h · a total hemispherical emissivity) of at least 0.86 at 482 ° C and preferably an emissivity of at least about 0.9 at 482 ° 0." This lower surface must emit most of the infrared radiation in a wavelength range from 3 »o to 5 | O microns and preferably consists of a non-metallic heat

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Resistant material with a high emissivity such as porcelain or the like ». The preferred · radiant panel 2 consists of sheet metal, for example sheet aluminum, sheet steel or the like «with a thickness of 0.3 cm or less, which is coated on both sides with a dark colored porcelain of high emissivity «

The radiant panel 2 must have a relatively large lower area of at least 0.1 square meters, preferably the area is 0.3 to 0.6 square meters. The lower wall of the radiant panel 2 can be hemispherical. ^ö ie however preferably formed for use with a flat heating element generally flat "Such a cup-shaped Btrahlplatte usually has a depth of 2.5 to 7.6 cm and a diameter of 4o to 1oo cm, preferably 6o-8o cm · Although the Radiant panel 2 usually has a flat central part 13 and a rounded side part, as shown in the drawing, the design of the radiant panel 2 can be modified by adding decorative patterns. corresponds to a bowl or even a hemisphere · There can also be reverse bends if the resulting shape of the radiant panel 2 does not interfere with its attachment. Similar changes in the appearance and shape of the housing 1 are also possible, especially if a special reflector 5o is provided will « ^j

The housing 1a is preferably shaped like the radiant panel and usually has a height of 2.5 to 12.7 cm. It is usually made of sheet metal, for example aluminum «* sheet metal or sheet steel, and can be painted or the like «or The housing 1a preferably has thin walls and a wall thickness of less than 0.3 cm and more preferably a light weight * ee is with the radiant panel 2 connected in such a way that «in a sealed space with a

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Height is formed of 7.6 cm to 2o _e ^ü ieser space preferably has a diameter of 3 to 8 times its height "

In order to reduce the heat loss through the housing, it is desirable to lower its temperature! for example by use of an insulator such as the insulating layer 16b, or by formation of an air space between the Heflektor 5o and the housing 1a · The heat transfer to the housing 1a can be further reduced by the fact that with an internal surface of low absorption capability or with a polished or _o it reflektierenden- In the illustrated embodiment, the housing 1a has a reflective surface 5b on the inside corresponding to the surface 5 according to FIGS. 1 and 2. Such a reflective surface preferably has a dimension of 0.3 to 0.6 square meters have ₉ is {however. Preferred * - »wise flat ·

The reflector 5o may have a slight curvature, but is preferably generally flat or is generally parallel to the heating element 3. The hand of the reflector protrudes radially outward from the heating element 3 and is about 0.6 * cm from the side wall Jo of the housing or of the edge flange 8 of the beam plate 2 · away TIIE lower reflective surface 5a of the reflector $ o is preferably configured mirror-like and can be highly polished chrome-plated or "" the properties of the upper surface of the reflector are not critical. The reflector 5o can be made of thin sheet metal or foil and consist of aluminum or numerous other metals «

The reflector 5o is preferably about 5 to 10 cm from Central part 31 of the housing 1 a removed so that at least there is an insulating air space above the reflector J? o to allow the heat transfer to the housing 1a · Of course, this heat transfer

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Can be further reduced by the air space through aluminum foil or additional reflectors similar to that Reflector 5o is divided, but this is not essential The meaning is · § if necessary, the - as already mentioned - by the housing 1a and the radiant panel enclosed, sealed tree partially evacuated or be filled with an inert gas or with a gas that has a low thermal conductivity «

In the case of the radiant heater according to the invention, the heating element is 3 preferably the only heat source. It can be of conventional design, so that the majority of the delivered Infrared radiation is in the wavelength range of 2 to 3 microns «You electrical equipment should be able to do that Heating element 3 to a temperature of 76o ° O to 86o ° 0 or «to a temperature which is sufficient to achieve the desired jet temperature on the lower surface 13 of the radiant panel 2 to give »The temperature of the heating element 3 should be kept at 76o ° 0 to 86o ° E, so that the lower surface of the central part 13 has a temperature of about 4 · 3ο to about 51o ° 0.

The shape of the heating element 3 can vary widely however, a heating element is preferred whose turns are generally parallel to the central portion 13 of the infrared radiation plate 2 lie. The coiled heating element 3 and this central part 13 of the radiant panel 2 are preferably generally flat. the diameter of the coiled heating element 3 is generally in the range of 30 to 90 cm and is ordinary 5 to 10 cm smaller than the inner diameter of the edge flange 8, so that the circumference of the coiled hot elements 2.5 up to 5 cm away from the edge of the radiant panel 2l. Preferably the diameter of the coiled heating element is 50 to 75 cm for those made according to the invention for practice Radiant heater. The thickness of the individual turns

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dos heating element can be different You is usually o _f 8 cm to 1.5 x

In the case of an electric radiant heater of the type shown in FIG. 3, the heating element 3 is about 2.5 to 3.8 cm from the yeast deflector 5o and about 2.5 to 3.8 cm from the central part 13 of the radiant heat 2. The central part 13 of the radiant panel 2 is preferably maintained at a temperature of from about 454 ° C to about 482 ° O. For a typical commercial electric radiant heater, the housing 1a can have a diameter of 80 cm and a height of 10 cm, the radiant panel 2 can have a diameter of 80 cm and a height of 5 cm, while the coiled heating element 3 has a diameter of 72 cm and has a thickness of 1.3 cm, whereby the insulating layer 16B can have a thickness of 1.3 cm and the deflector 5o can have a diameter of 75 cm cm from the reflector 50 and its lower surface is at the same distance from the central part 13 of the radiant panel 2, so that the surface of the radiant panel 2 is heated to a temperature of 482.degree. The upper surface of the radiant panel is of course at a considerably higher temperature. In such a heat radiator, which consists of sheet metal beam plate 2 is preferably nits on both ^ü coated with a commercial glazed porcelain * The outer surface of the housing 1 or "1a can also be coated with porcelain or other heat resistant or _e korossionsbeständigen material, but this is not essential "

A typical heat radiator according to the invention, the has an output of 6,000 watts and at which the temperature on the lower surface of the radiant panel is 2,482 ° C, can be suspended from 2.4 to 4.9 m above the to

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heating surfaces distribute the infrared heat energy to the irradiated objects over a wide area, i.e. up to a diameter of about 5i5 m »

Although the coiled heating element 3, the radiant panel and the reflector 5 or «5o (either with or without special Housing) have a flat circular shape in the manner described, the overall shape of the radiant heater can can be modified, resulting in a slightly different efficiency. For example, the plan shape can be according to Fig. 1 into an oval, elliptical, square, rectangular, rhomboid, triangular or other shape can be modified. In the same way, the vertical waste can be changed so that it is circular, rectangular or takes on a different form.

Of course, in the example shown, ·! Changes are made, in particular by replacing individual technical means Equivalents without departing from the scope of the invention »-. *

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Claims (1)

Patent attorneys
Dipl. Ing. Walter Meissner Munich 2, Tal 71 or Claims 1 «infrared heat radiator with an electrical heating element arranged in a housing and a reflector, characterized in that an infrared radiation plate (2) is provided below or in front of the heating element (J), the upper surface of which has an absorption capacity of at least 0.86 at a temperature of 482 ° 0 and the lower surface of which has an emissivity of at least o _t 86 at a temperature of 482 ° 0, the lower surface having an extent of at least 0.1 qm and the main part of the radiation in the wavelength range of 3, o emits up to 5.0 microns, and that the reflector (5.5o) has a reflector surface of at least 0.1 square meters, 2 _# infrared heat radiator according to claim 1, characterized in that the metallic radiant plate (2) has a flat central part (u) and is coated with a heat-resistant material of high emissivity, and that the lower surface of the radiant plate (2) has an extent o having at least 3 square meters and the ^ß trahlplatte (2) extending radially outside to over the periphery of the heating element (3) addition " 3 · Infrared heat radiator according to claim 1, characterized gekennzeichne t that the lower surface of the radiant panel (2) is made of a porcelain layer with high 909825/1172 -je - · Emissivity is formed and radially outwards over the circumference of the heating element (3) hinaxis extends. 4. Infrared heat radiator according to claim 1, characterized characterized in that means are provided to keep the coiled heating element (3) at a temperature of 76o to 86o ° 0, and that the radiant panel (2) is so close to the heating element (3) is that its lower surface is heated by the heating element (3) to 37o to 54-0 ° ö when the heating element (3) is at the specified temperature, 5 · Infrared heat radiator according to claim 4, characterized characterized in that the radiant panel (2) and the housing (1) are connected to one another at the edge so that a closed space with a diameter of about 6o to 8o cm and a height of about 7 »6 to 20 cm is formed is. 6 · Infrared heat radiator according to claim 5, characterized characterized in that the coiled round heating element (3) is generally parallel to the radiant panel (2) and is about 2.5 to 3.8 cm from the upper surface of the radiant panel (2), 7, infrared heat radiator according to claim 1, characterized in that the radiant panel (2) has a flat central part (13), a rounded side part (14) and an edge flange (8), and the lower surface of the radiant panel (2) has a dimension of about 0.3 to 0.6 square meters, and that the bowl-shaped housing (1) has an edge flange (7) with which it is attached to the edge flange (8) of the radiant panel (2), and that the Heating element (3) from the housing (1) in a horizontal position and in the 909825/1172 generally parallel to the flat central part (13) of the radiant panel (2) and at a distance of about 2.5 to about 3.8 of it is held, with the circumference of the coiled heating element (3) about 2.5 to about 5 »ο radially spaced from the edge flanges (7,8) and the reflector (5) is attached to the housing (1) and about a distance of about 2.5 to about 3 »8 cm above the heating element (3) and at a distance of about 5 to about 1o cm from the central part (15) of the housing (1), so that at least one insulating air space above the reflector (5o) is formed. ) 8 »Infrared heat radiator according to claim 7 * characterized in that a reflector surface (5) with a dimension of at least 0.1 square meters is formed on the inner surface of the central part (15) of the housing (1)» 9. Infrared heat radiator with an electrical heating element arranged in a housing and a reflector, characterized in that an infrared radiation plate (2) is provided below or in front of the heating element (3), the upper and lower surfaces of which are made of a heat-resistant material of high Emissivity are formed, the lower surface emits the main part of the radiation in a wavelength range of 3, o to ^^ microns, and that the reflector (5) extends radially outward beyond the circumference of the coiled heating element (3) also to the To reflect heat down from the heating element (3) to the radiant panel (2), and that means are provided to feed the heating element (3) with electrical current and the lower surface of the radiant panel (2) to ice and> temperature to be heated from about 37o ° to 5 ^ o ° O. 1o. Infrared heat radiator according to claim 9 »characterized ; - »indicated that means are provided to ^ j the heating element (3) to a temperature of about 76o ° to about 86oo _{0 on Zulieizeil} . 11, Infr aro t warmth afterwards. Claim 1o _f, characterized in that the heating element (3) is at a distance of about 2.5 "to about 3 | 8 cm from the upper ^ surface of the radiant panel (2), 12, infrared heat radiator according to claim 11, characterized in that the reflector (5o) is at a distance of about 2.5 to 3.8 cm from the heating element (3) lies. 13, infrared heat radiator according to claim 11, characterized in that between the reflector (5o) and the housing (1a) an insulating air space with a height of about 5 to about 1o cm is provided is, 14, infrared heat radiator according to claim 13, characterized in that the reflector (5o) on its back is covered with a layer of fibrous heat-insulating material # 15 · Infrared heat radiator according to claim 9t characterized in that the round radiant panel (2) has a diameter of about 6o to about 8o cm and is attached with its edge flange (8) to the edge flange (7) of the housing (1) in a sealing manner, 16, Method for increasing the radiant heat output of an electric infrared heat emitter in one Housing arranged electrical heating element and a reflector above the heating element, which the radiant heat reflected downwards, - thereby identified * records that the heating element (3) is heated to a temperature of about 76o ° to about 86o ° Ö, and one thin-walled infrared radiant panel (2) closely spaced below 909825/1172 4b the heating element (3) is arranged so that the lower surface of the radiant panel (2) is ^{heated to a temperature of about 4-3o ° to about 5I0 0} G by the heat radiation transmitted to the radiant panel (2), and that the lower surface is at least 0.1 square meters in size and is made of a material that has an emissivity of at least 0.86 at 482 ° O and emits the majority of the radiation from its lower surface in the wavelength range from 30 to 50 microns 17 · The method according to claim 16, characterized in characterized in that the upper and lower surfaces of the radiant panel (2) are coated with a porcelain that has an emissivity of at least about 0.9 at 4-82 ° O has 18 · The method of claim 16, labeled in characterized »characterized in that the jet plate (2) of a closed, the heating element is in the housing (1> imgesetzt Aer space formed at a pressure below atmospheric ^ rucks brought Haum (3) containing a bottom part , ' 19 · The method according to claim 16, characterized in marked t that the lower surface of the radiant panel (2) at a temperature of about 4-54 ° O to about 4θ2 ° O is held »■ 1-17 2