DE102005018454A1 - Radiant heaters - Google Patents

Abstract

The invention relates to a heat radiator in rod form, consisting of a light source, a housing and a reflector, wherein the light source is the housing for the light source from a full length of the light source covering and the light source on all sides surrounding glass envelope is formed, the radiation exit surface on the front and has a reflector surface on the back, wherein the reflector, seen in cross section, is parabolic.

Description

The The invention relates to a heat radiator in rod form consisting of a light source, a housing and a reflector.

Rod-shaped heat radiators are known as so-called round tube or as a double tube with reflector. So is out of the DE 4438870 (Heraeus Noblelight) discloses an elongate radiation source type infrared radiator using a fused silica capillary tube containing a carbon fiber ribbon as a resistive body. In the infrared emitter after DE 10029437 the quartz glass tube is designed as a double tube radiator, wherein the back is provided with a reflection layer.

The for heating used by products spotlights with circular or elliptical cross-sections (Double tube emitters) emit the radiation in a large emission cone. This is only a small part of the technically usable radiation for warming used the products. The achievable with the known radiators area performance for heating of products is therefore not optimal.

task The present invention is a heat radiator of the aforementioned Manufacture of stick-type glassy material containing the above-mentioned Disadvantages does not have and a small Abstrahlkegel and thus an increase the yield of technically usable radiation allows.

These The object is achieved by the in the claims specified characteristics solved.

An inventively designed heat radiator with a straight front surface is in 1 shown. This already allows a narrow beam angle through the parabolic curved reflection wall.

An inventive heat radiator with a spherical or convex lens on the front is in 2 shown. Here, the radiation angle decreases in accordance with the lens curvature, so that a zone with very strong radiation and the focusing of the emitted beams is achieved.

in the Following, the invention will be explained in more detail with reference to several embodiments.

It demonstrate:

1 Spotlight with parabolic reflector geometry

2 Spotlight with integrated lens

3 Radiator according to the prior art

4 Radiator according to the prior art

In 1 is the spotlight ( 1 ) with a light source ( 2 ), a housing ( 3 ) and a reflector on the back. The housing is made of quartz glass, which surrounds the light source like a shell ( 2 ), wherein a radiation exit surface ( 5 ) on the front and the reflector surface ( 4 ) is located on the back.

In a parabolic reflector, the result in 1 shown radiation intensities, wherein in the overlap region of many rays, a higher heat intensity is achieved than in the outdoor area. The parabolic shape of the reflector prevents radiation in the vitreous from running dead by reflections.

In 2 an alternative form of the heat radiator according to the present invention is shown. Here, the quartz glass envelope has a lenticular thickening on the front side, so that the emission angle α is considerably reduced in comparison with the example according to FIG 1 , Preferably, the radiation angle α is in the range of 50 ° to 60 °.

For comparison with the heat radiator according to the invention, the beam paths of a conventional round tube radiator with reflector and a conventional double-tube radiator with reflector in the 3 and 4 shown. It can be seen that the emission angle in a conventional round tube emitter is approximately 180 ° with a uniform radiation distribution. In the conventional double-tube reflector with the reflector of the beam angle is also at about 165 °, however, it results from reflected radiation, an area with increased radiation power, due to the reflector shape, a portion of the radiation is reflected so long in the radiator back and forth until the radiant energy completely in Heat was converted. In addition, however, much of the emitted power is scattered over the entire beam angle and does not contribute to increasing the maximum beam power density.

By the spotlight with the parabolic reflector is achieved that due to the optimized beam path less Radiation power converted by reflection back and forth in heat which is then increased by cooling capacity dissipated must be because the reflector layer no arbitrarily high temperatures tolerates.

By integrating the lens into the radiator will approximate all exiting radiation is refracted to the center of the radiator. This creates a long cone radiating from the other Spotlights due to the bundling the rays a much higher Single beam power density generated.

One Another advantage is that due to the sharp demarcation of the Radiation cone it possible is only certain areas of the product to heat and targeted e.g. to produce a temperature profile in the product.

The Lens creates a focal point in which the power density is extreme increases. This focus has advantages for certain applications e.g. at the welding wire preheating.

Claims (7)

Radiant heater in rod form, consisting of a light source, a housing and a reflector, characterized in that the light source is formed the housing for the light source from a full length of the light source covering and the light source on all sides surrounding glass envelope, which has a radiation exit surface on the front and a reflector surface on the back, wherein the reflector is seen in cross-section parabolic. Radiant heaters according to claim 1, characterized in that the glass envelope at the Front a lenticular, outward domed Has thickening. Radiant heaters according to the preceding claim 2, characterized in that the thickening consists of a convex lens, with the reflected Rays in a linear Focus bundled are. Radiant heaters according to one of the preceding claims, characterized that a cavity exists between the thickening and the reflector, in which the light source is arranged. Radiant heaters according to one of the preceding claims, characterized that the back the heat radiator is provided with a reflection layer. Radiant heaters according to one of the preceding claims, characterized that the reflection layer with the back of the heat radiator is integrated. Radiant heaters according to one of the preceding claims, characterized in that the light source is in the form of a rod, a band or a helix is.