Radiation burners or glow radiators

[57] ABSTRACT

A radiation burner or glow radiator, in which a combustible mixture of gas or fuel vapor and air is supplied from a distribution chamber to a permeable burner head, which comprises an insulating layer of heat-resisting and/or fireproof material, for instance a fiber fleece, provided with discrete passage apertures for the combustible mixture, the burner head also comprising a heat-radiating surface of heat-resisting and/or fireproof material, consisting of one or more hollow moulded bodies provided with outlets, in such a way that burning gases issuing from these outlets impinge upon an external surface of an adjacent region of a heat-radiating surface.

Claims, 7 Drawing Figures

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PATENTED may 91972

3,661,499

SHEET 1 OF 3

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FIG. Ί

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INVENTOR

KURT KRIEGER

BY

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firri A de rs

PATENTED mat 91972

3.661,499

TJHEET 2 OF 3

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FIG. 5

INVENTOR

KURT KRIEGER

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A 77ΟΛ. rteS Y

PATENTED MAY 91972

3,661,499

SHEET 3 OF 3

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FIG. 6

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FIG. ?

INVENTOR

KURT KRIEGER

3,661,499

RADIATION BURNERS OR GLOW RADIATORS

This invention relates to a radiation burner or glow radiator in which a combustible mixture of gas or fuel vapor and air is supplied through a distribution chamber to a permeable burner head, which comprises an insulating layer of heat-resistmg or fireproof material, for instance a fiber fleece provided with discrete passage apertures for the combustible mixture, and also a heat-radiating surface of heat-resisting or fireproof material located towards the outside of the burner and played upon by hot combustion gases.

In the case of one known burner of this kind, described in French Pat. No. 1,511,696, the heat-radiating surface consists of a heat-resisting metal plate. Between this and the insulating layer, provided with discrete apertures, there is an intervening space, in which the combustible mixture bums, thereby heating the metal plate from its rear side. The burnt gases pass directly forwards into the atmosphere through holes provided m the metal plate.

The object of the present invention is to develop further and ²⁰improve a burner of the kind hereinbefore set forth, in order to obtain particularly advantageous results, particularly with respect to its output capacity and/or efficiency, and to the temperature conditions.

For this purpose the invention provides that the heat-radiat- ²³ing surface consists of one or more molded bodies, exhibiting or forming cavities, and is provided with outlets leading outwards from the cavities, in such a way that the gases issuing from these outlets pass on to the outer side of an adjacent region of the heat-radiating surface.

The great advantage is thus yielded that the heat-radiating surface is not only heated from the inside, but that the outer side, the external surface, is also acted upon by hot gases These gases here impart further heat to the heat-radiating surface, so that a substantially better utilization of the energy of the fuel is obtained, and also an increase in efficiency. Owing to heat being supplied to the heat-radiating surface from both the inside and the outside, the heating here becomes more intensive, so that higher temperatures can be reached.

For the construction of the heat-radiating surface on the lines of this invention, there are various possibilities. These include substantially any constructions in which, by appropriate shaping of the heat-radiating surface, hot gases are deflected from the inside on to the outside of the heat-radiating surface. « In one instance the entire surface may be formed by one or ⁴³more molded bodies, the cross-sectional profile of which is a sequence of alternating projections and recesses, wherein the cavities to which the combustible mixture flows, and in which it is burnt, lie underneath the projections whereas in the falling 50 and rising flanks of this profile are arranged the outlets for the hot gases, through which the same issue, to impinge upon the opposite flank of the profile. The profile may here be acuteangled, or even rounded. The construction admits of being such that at times only one profile peak, with the flanks 55 descending on both sides, is formed by each molded body in which case a series of such molded bodies then lies parallel side by side, or else lies in such a way that one molded body contains or forms a number of hill-and-valley elements in one piece.

A further advantageous construction consists in the feature that the heat-radiating surface is formed of molded bodies which are provided in each case on two opposite sides with outlet apertures, while the inlets for the combustible mixture are located in positions located between these outlet aper- 65 tures, and which are arranged in staggered relationship to one another in such a way that in each case the outlet apertures of two adjacent molded bodies point in different directions. By this staggered arrangement the hot gases issuing from the outlet apertures at the ends of one molded body impinge upon the 70 closed portion of the adjacent molded body, and thereby heat the latter from the exterior.

The cross-sectional profile of the molded bodies may be closed or may even be open. The molded bodies may for instance be constructed in the shape of tubular elements of cir- 75 cular cross-section, or of a flattened round cross-section, or of a cross-section of basically angular form, corresponding substantially to a triangle resting upon one side.

The molded bodies may, according to the form of their cross-sections, be provided not only with outlet apertures at opposite ends, but also, if desired, with further outlets in the region of their side walls.

As material for the molded bodies there comes into consideration, m addition to fireproof ceramic materials, also for instance a heat-resisting metal alloy or the like.

The molded bodies also admit of being provided with inlet tubes for the combustible mixture. With respect to the material of these little tubes, what has been stated above correspondingly applies. The tubes may be made in one piece with the molded bodies, or may be connected either detachably or firmly with them. With each molded body either one inlet tube or a plurality of inlet tubes may be associated. In particular, the construction further admits of being such that the inlet tubes, also form the discrete passage apertures in the insulating layer, or serve as a lining for the latter

With each molded body there may be associated an insertion which forms an inlet tube for the combustible mixture and/or is equipped with an inlet tube.

A construction of the molded bodies which is also very advantageous in connection with the production consists in the feature that the same are provided with recesses issuing from open ends. These recesses may be selected, with respect to their number, size and shape, according to the particular requirements, and may form outlets for the hot gases.

Further details and features of the invention are more fully explained hereunder in connection with the accompanying drawing, m which: ^{J 6}

FIG. 1 shows in plan a part of a burner constructed according to the invention;

FIG. 2 shows a section on the line II—II in FIG 1

FIG 3 shows in plan a part of another burner construction according to the invention;

FIG. 4 shows a section on the line IV—IV in FIG. 3;

FIG. 5 shows in sectional elevation a modified burner construction;

FIG. 6 shows in plan a part of a further burner construction· and ’

FIG. 7 shows a section through another molded-body construction. ⁷

The burner illustrated in FIGS. 1 and 2 comprises a burner casing 1, with an inlet pipe 2 for a mixture of gas and air and with a distribution chamber 3, together with a rectangular burner head denoted as a whole by the numeral 4. The latter comprises an insulating layer 5, and a heat-radiating surface 7 formed by individual molded blocks 6. The insulating layer 5 consists of a fiber fleece, this being primarily a fleece of ceramic ffibem, or of fibers having an oxide basis. Although this has been found very advantageous, the provision of some other insulating layer, of solid ceramic material for instance is not precluded. ’

The insulating layer S rests upon a metal plate 8 or a wire network and is provided with discrete passage apertures for 60 the combustible mixture. With the construction shown these are formed by small tubes 10 of heatproof metal or else of ceramic material At the positions of the tubes 10 the metal plate 8 is provided with corresponding holes 9.

The tubes 10 form at the same time the inlet paths for the combustible mixture to the molded bodies 6, and also a hold&gt;g means for the latter, and may for instance be connected with the molded bodies 6 in a suitable manner by an upset collar or a flange, etther fixedly, or, it may be, in such a way as to allow a slight relative movement.

;^oid^°^dies 6 consist, in the burner construction illustrated in FIGS. 1 and 2, of tubular elements of triangular cross-section, so that there are open cavities H at the ends The material of the molded bodies 6 may be a heat-resisting ’ ?™^StanCL^{a nickel}-^chr°mium alloy, or even a ceramic material. The molded bodies 6 are individually staggered in

3,661,499 relation to one another, so that each molded body extends transversely to the molded bodies adjacent to it.

The combustion of the combustible mixture flowing in through the tubes 10 takes place in the cavities H of the molded bodies 6, whereby these are heated in an outward direction from within. The hot gases then issue from the outlet apertures 11 formed by the open ends of the molded bodies 6, and impinge upon the outsides of the adjacent molded bodies. By this means each molded body 6 is heated not only outwards from within but also on its outside.

With the burner construction illustrated in FIGS. 3 and 4, the heat-radiating surface 7 is formed by a molded body 15,’ the cross-sectional profile of which is an alternating sequence of projections 15α and recesses 15*. The burner head 14 here again comprises an insulating layer 16 of a fiber fleece, which, towards the distribution chamber 3 of the burner, is covered’ by a metal plate 17, and which is provided with discrete passages in the form of tubes 18. Through the latter the combustible mixture passes into the cavities H, which are enclosed by the molded body 15, and in which the combustion is effected. The flanks 15c of the molded body profile are provided with outlet apertures 19, through which the hot gases issue, to impinge upon the outside of an adjacent flank of the profile and additionally heat the latter. The single corrugated body 15 may alternatively be replaced by an assemblage of individual members of triangular cross-section.

FIG. 5 illustrates a burner construction in which, as in the construction of FIGS. 1 and 2, over an insulating layer 20, with inlet tubes 21, molded bodies 22 are arranged in staggered relationship to one another. These molded bodies 22 here have a somewhat M-shaped cross-section. Besides the outlet apertures 23 formed by the open ends of the molded bodies 22, further outlets are here provided in the form of holes 24 in inner wails 22α that face one another in each molded body itself. The hot gases issuing through these outlets 24 therefore additionally heat these walls 24 of the molded body 22 on their outer sides.

In the burner construction illustrated in FIG. 6, the heatradiating surface 7 is composed of individual molded bodies 25, the basic form of which is the same as or similar to those of the molded bodies 6 shown in FIG. 2. Here, however, the molded bodies 25 are not arranged in staggered relationship to one another, but have the same directional orientation among themselves, so that a profile of the heat-radiating surface is obtained which is comparable with the construction of FIGS. 3 and 4. Each of the molded bodies 6 is provided with recesses 26, which issue from the open ends of the molded body 25, and form outlet apertures for the gases, which can accordingly impinge upon the outer sides of the adjacent molded bodies. The recesses 26 at one end of each molded body 25, as shown in FIG. 6, are located to one side of the peak of the profile of the molded body, and at the other end on the other side of the profile peak.

In FIG. 7 is shown a burner construction in which there is associated with each molded body 27 an insertion 28 consisting for example of ceramic material, which in its upper portion is of plate-like or slab-like construction, and in its lower portion, engaging in the insulating layer 30, is equipped with a little metal tube 29. Through this tube, and the part of the insertion 28 connected therewith, the combustible mixture flowing in from the distribution chamber 3 passes into the molded body 27, to be burnt there. The molded bodies 27 may be constructed as shown in FIG. 6, or may even be of some other suitable construction.

All the features mentioned in the foregoing description and/or illustrated in the accompanying drawings, are to be regarded, in so far as the known state of the art permits, either in themselves alone or else in combination, as falling within the invention, even if they are not expressly mentioned in the claims.