Abstract
Burner (10), in particular for a vehicle heater (12), having an orifice plate (14) separating an inner combustion region (16) from an outer region (18), wherein a photosensitive sensor (20) is arranged in the outer region (18), wherein at least two separate air inlet openings (22, 24, 26, 28) are being provided in the orifice plate (14), wherein one of the at least two air inlet openings (22, 24, 26, 28) is additionally formed as a light opening (28) which also allows light to pass from the inner combustion region (16) to the photosensitive sensor (20) that is arranged in the outer region (18), wherein the at least two air inlet openings (22, 24, 26, 28) are being shaped such that the same combustion air quantities flow into the internal combustion region (16) per unit time, respectively, and wherein the orifice plate (14) is transparent and/or the light opening (28) has a shape different from the air inlet openings (22, 24, 26) that are not formed as light opening such that an illumination area defined by the light opening (28) is larger than a reference illumination area defined by one of the at least two air inlet openings (22, 24, 26) that are not formed as light opening (28).
Claims
1. Burner for a vehicle heater, having an orifice plate separating an inner combustion region from an outer region, wherein a photosensitive sensor is arranged in the outer region, wherein at least two separate air inlet openings are being provided in the orifice plate, wherein one of the at least two air inlet openings is additionally formed as a light opening which also allows light to pass from the inner combustion region to the photosensitive sensor that is arranged in the outer region, wherein the at least two air inlet openings being shaped such that the same combustion air quantities flow into the inner combustion region per unit time, respectively, and wherein the orifice plate is transparent and/or the light opening has a shape different from the air inlet openings that are not formed as light opening such that an illumination area defined by the light opening is larger than a reference illumination area defined by one of the at least two air inlet openings that are not formed as light opening.
2. Burner according to claim 1, wherein the orifice plate consists of a metallic material or a heat-resistant plastic or a transparent mineral.
3. Burner according to claim 1, wherein the at least two air inlet openings with respect to their respective centers in the plane of the orifice plate jointly define a geometric pattern with a symmetry rotation axis of order two or more.
4. Burner according to claim 1, wherein the light opening consists of a plurality of individual openings separated from one another.
5. Burner according to claim 4, wherein the individual openings, which together form the light opening, form a grid pattern.
6. Burner according to claim 1, wherein the light opening comprises at least sections of slot-like regions.
7. Burner according to claim 1, wherein the orifice plate is at least partially thermally insulated from other components of the burner.
8. Burner according to claim 1, further comprising an internal wall defining the inner combustion region.
9. Burner according to claim 8, wherein the orifice plate is mounted to an outer edge of the internal wall to separate the inner combustion region from the outer region.
10. Burner according to claim 8, further comprising a seal arranged on an edge of the orifice plate.
11. Burner according to claim 10, wherein the seal is arranged between the orifice plate and the wall.
Description
(1) This disclosure is described in the following with reference to the accompanying drawings on the basis of preferred embodiments.
(2) It shows:
(3) FIG. 1 an orifice plate with a first light opening;
(4) FIG. 2 an orifice plate with a reference opening;
(5) FIG. 3 an orifice plate with a second light opening;
(6) FIG. 4 an orifice plate with a third light opening;
(7) FIG. 5 an orifice plate with a fourth light opening;
(8) FIG. 6 an orifice plate with a fifth light opening;
(9) FIG. 7 an orifice plate with a sixth light opening;
(10) FIG. 8 an orifice plate with a seventh light opening;
(11) FIG. 9 an orifice plate with an eighth opening;
(12) FIG. 10 a vehicle heater with a burner in a schematically simplified manner;
(13) FIG. 11 a vehicle heater with a burner in a schematically simplified manner with a shifted opening;
(14) FIG. 12 a vehicle heater with a burner in a schematically simplified manner with a reference opening;
(15) FIG. 13 a prior art burner in a partially cut open representation; and
(16) FIG. 14 a detail of the state of the art burner.
(17) In the following description of the drawings, identical reference numerals denote identical or similar components.
(18) FIG. 1 shows an orifice plate with a first light opening. The shown orifice plate 14 is essentially circular. A number of air inlet openings 22, 24, 26 with their respective centers 22′, 24′ and 26′ are recognizable. Furthermore, air inlet openings not further marked with reference signs are recognizable. In the lower area of the orifice plate 14, an opening specially shaped as a light opening 28 is recognizable in the orifice plate 14. The light opening 28 is not closed and also serves for the passage of combustion air through the orifice plate 14. The light opening 28 has a center 28′. All centers 22′, 24′, 26′, 28′ of the air inlet openings 22, 24, 26 and the further air inlet opening designed as light opening 28 are arranged concentrically around a center of the orifice plate 14, which represents a symmetry rotation axis 38 of order two or more. For example, the centers of all air inlet openings and the air inlet opening designed as a light opening can be brought into alignment again and again by successive rotations of the orifice plate 14 by 45° each, so that in the present case there is a symmetry rotation axis 38 of order eight. This high symmetry allows an extremely even passage of combustion air through the orifice plate 14. The outer shape of the light opening 28 shown in FIG. 1 resembles a six-armed ‘snowflake’. The passage area released by the light opening 28 shown in FIG. 1 is dimensioned in such a way that the pressure drop at the light opening 28 corresponds to the respective pressure drop at the individual air inlet openings 22, 24, 26, which are not designed as light opening. In this way, during operation of a burner equipped with the orifice plate 14, the same quantity of combustion air per time unit will pass through each of the air inlet openings 22, 24, 26 and the light opening 28 through orifice plate 14.
(19) The ramifications of the light opening 28 recognizable in FIG. 1 enlarge the area “illuminated” by the light opening 28, i.e. the illumination area. Clearly visible is the light opening 28, including the constrictions contouring the light opening 28, significantly larger than the other air inlet openings 22, 24 and 26, which are not designed as light opening. The light opening 28 resembles a star. Nevertheless, the same amount of combustion air per time unit passes through the opening 28 as through the other individual air inlet openings.
(20) FIG. 2 shows an orifice plate with a reference opening. Instead of the light opening 28 shown in FIG. 1, FIG. 2 shows a reference opening 40 at the same position of the orifice plate 14. The reference opening 40 has the same external shape and dimensions as the other air inlet openings 22, 24, 26. A reference illuminating area is thus defined by the reference opening, which corresponds in its shape to one of the other air inlet openings 22, 24, 26, which will be explained in more detail below in connection with FIGS. 10 to 12.
(21) If a suitable transparent material is chosen as the material for the orifice plate 14, the light opening 28 may preferably be designed such that its external shape is identical to the external shapes of the other air inlet openings 22, 24, 26. This has the advantage that the orifice plate 14 is particularly easy to manufacture. Due to the transparency of the orifice plate 14, the resulting illumination area is essentially unlimited, regardless of the shape of the light opening 28, since light can pass through the entire orifice plate 14.
(22) FIG. 3 shows an orifice plate with a second light opening 28. The light opening 28 shown in FIG. 3 consists of a plurality of individual openings, each separated from the adjacent openings by thin webs. The plurality of individual openings and the thin webs separating these individual openings from each other are together considerably larger than the other air inlet openings, which are not designed as light opening 28. The light opening 28 shown in FIG. 3 is made up of a combination of several geometric shapes. Nevertheless, the same amount of combustion air per time unit passes through the orifice plate through the opening 28 as through the other individual air inlet openings.
(23) FIG. 4 shows an orifice plate with a third light opening. The light opening 28 shown in FIG. 4, like the light opening 28 shown in FIG. 3, consists of a plurality of individual openings separated by thin webs which, taken as a whole, remind of the shape of a flower or a rosette of “pieces of cake”. The plurality of individual openings and the thin webs separating them from each other are, in terms of their area, much larger than the other air inlet openings, which are not designed as light opening. Nevertheless, the same amount of combustion air per time unit passes through the orifice plate through the light opening 28 as through the other individual air inlet openings.
(24) FIG. 5 shows a further orifice plate with a fourth light opening. The light opening 28 shown in FIG. 5 is formed as a regular grid with square grid openings, which in their entirety, i.e., the grid openings and the individual webs separating the grid openings from each other, have a significantly larger area than the other air inlet openings which are not designed as light opening 28. Nevertheless, the same amount of combustion air per time unit passes through the orifice plate through the light opening 28 as through the other individual air inlet openings. In addition to the grid shown in FIG. 5, any other geometric basic elements for the grid providing the light opening are also conceivable. This also includes grids of unstructured forms, which can consist of a large number of polygonal grid openings differing from each other and individual webs separating the grid lattice openings from each other.
(25) FIG. 6 shows another orifice plate with a fifth light opening. The light opening 28 shown in FIG. 6 is constructed as a regular arrangement of circular individual openings, each arranged on circular lines around a central opening. Here, too, the individual openings, together with the webs separating the individual openings, are considerably larger than the other air inlet openings, which are not designed as light opening. Nevertheless, the same amount of combustion air per time unit passes through the orifice plate through the light opening 28 as through the other individual air inlet openings.
(26) FIG. 7 shows another orifice plate with a sixth light opening. The light opening 28 shown in FIG. 7 comprises a central opening and, separated from it by thin webs, a plurality of surrounding smaller openings. The smaller openings are essentially arranged along a concentric circumferential line on which the centers of the other air inlet openings and the light opening 28 itself lie. The outer shape of the plurality of individual openings and the thin webs separating them from each other is accordingly oval. Due to this oval outer shape, the light opening 28 shown in FIG. 7 is particularly suitable for compensating a twisting of the orifice plate 14 around the symmetry rotation axis 38. Also with the light opening 28 shown in FIG. 7 the same amount of combustion air per time unit passes through the orifice plate through the light opening 28 as through the other individual air inlet openings.
(27) FIG. 8 shows another orifice plate with a seventh light opening. The light opening 28 shown in FIG. 8 consists of a central opening framed at the sides by crescent-shaped secondary openings. In this way, an oval-like overall shape of the light opening 28 is created, divided by two webs, which tolerates twisting of the orifice plate during its mounting particularly well. Also with the light opening 28 shown in FIG. 8 the same amount of combustion air per time unit passes through the orifice plate through the light opening 28 as through the other individual air inlet openings.
(28) FIG. 9 shows another orifice plate with an eighth light opening. The light opening shown in FIG. 9 consists of a plurality of narrow slots arranged parallel to each other, each separated from each other by thin webs. The orientation of the slots can essentially be freely chosen. Also with the light opening 28 shown in FIG. 9 the same amount of combustion air per time unit passes through the orifice plate through the light opening 28 as through the other individual air inlet openings.
(29) FIG. 10 shows a vehicle heater with burner in a schematically simplified manner. The vehicle heater 12 with the burner 10 is recognizable. The burner 10 comprises an inner combustion region 16 and an outer region 18, wherein the inner combustion region 16 is separated from the outer region 18 by an orifice plate 14. Fuel is fed into the inner combustion region 16 via a fuel supply 42, which can be designed as an atomizer nozzle with connected fuel supply, for example. Combustion air is supplied from the outer region 18 into the inner combustion region 16 through the orifice plate 14, wherein the combustion air flows through air inlet openings 22 and a light opening 28. In a simplifying way, only one air inlet opening 22 is shown. An insulating seal 56, which can be arranged in particular at an edge of the orifice plate 14, can thermally insulate the orifice plate 14 from other components of the burner 10, in particular components which limits the inner combustion region 16. In addition to thermal insulation, the insulating seal 56 can also prevent leakage at the edge of the orifice plate so that at the edge of the orifice plate 14 no false air can pass from the outer region 18 to the inner combustion region 16. A flame 44 is usually present in the inner combustion region 16 during operation of the vehicle heater 12. The flame 44 emits light which emerges through the light opening 28 from the inner combustion region 16 to the outer region 18. The outer edge of the light opening 28 limits the bundle of light beams falling out of the inner combustion region 16, whereby edge beams 48, 50 are indicated. FIG. 10 further shows a deflecting device 46, which can be designed as a reflecting surface, for example, and which deflects the bundle of beams exiting the inner combustion region 16 through the light opening 28 in the direction of a photosensitive sensor 20, which is arranged in a plane 52. As long as the photosensitive sensor 20 is in the area between the edge beams 48, 50, a reliable detection of the flame 44 in the inner combustion region 16 is ensured by the photosensitive sensor 20. Due to tolerances in manufacturing of the orifice plate 14 and in mounting of the vehicle heater 12, in particular mounting of the orifice plate 14, the position and size of the light opening 28 in the beam path can vary slightly, so that the area illuminated by the light beams, which is limited by the edge beams 48, 50, can deviate in its position from device to device. In the worst case, the edge beams 48, 50 can illuminate an area which is completely beside the photosensitive sensor 20, or only partially illuminates it, so that a reliable detection of the flame 44 is no longer guaranteed. By enlarging the light opening 28 in relation to the air inlet openings 22, this problem can be avoided within the limits of tolerances without negative effects on the quality of combustion in the inner combustion region. The edge beams 48, 50 define in plane 52, in which the photosensitive sensor 20 is arranged, an illumination area which is indicated below the plane 52 by the double arrow. A possible subdivision of the light opening 28 into a plurality of individual openings by thin webs or similar opaque sections is not relevant for the illumination area, since then a plurality of edge beams generates overlapping individual areas in plane 52, which together form the illumination area. If the orifice plate 14 itself is transparent, the illumination area has practically no edge.
(30) FIG. 11 shows a vehicle heater with a burner in a schematically simplified manner with an offset orifice plate. In the case of the vehicle heater 12 shown in FIG. 11, the light opening 28 is shifted by an offset 54 with respect to the situation shown in FIG. 10. Due to the offset 54, the optical conditions change such that the two edge beams 48, 50 in the figure hit the plane 52 with an offset to the left and the photosensitive sensor 20 is only partially illuminated. The offset 54 of the light opening 28 can be caused, for example, by an inaccurate mounting of the orifice plate 14, for example, by twisted mounting of the orifice plate 14 with respect to a target position.
(31) FIG. 12 shows a vehicle heater with a burner in a schematically simplified manner with a reference opening in the orifice plate. A reference opening 40 is provided in FIG. 12 instead of the light opening 28 present in FIGS. 10 and 11 in the orifice plate 14. In particular, the reference opening 40 may have the same dimensions as the other air inlet openings 22 in the orifice plate 14. In particular, the centers of the reference opening 40 and the light opening 28 provided in FIG. 10 may coincide in order to ensure that the reference illuminating area generated by the reference opening 40 on the plane 52 is comparable. The edge beams 48, 50 given by the reference opening 40 limit the reference illumination area on the plane 52, which is indicated by the smaller double arrow below the plane 52. The larger double arrow underneath corresponds to the double arrow shown in FIG. 10, which belongs to the illumination area defined by the wider light opening 28 opposite to the reference opening 40.
(32) The features of the disclosure as described above, in the drawings as well as in the claims can be essential for the realization either individually or in any combination.
REFERENCE NUMERALS
(33) 10 burner
(34) 10′ burner
(35) 12 vehicle heater
(36) 14 orifice plate
(37) 14′ orifice plate
(38) 16 inner combustion region
(39) 16′ inner combustion region
(40) 18 outer region
(41) 18′ outer region
(42) 20 photosensitive sensor
(43) 22 air inlet opening
(44) 22′ center
(45) 24 air inlet opening
(46) 24′ center
(47) 26 air inlet opening
(48) 26′ center
(49) 28 light opening
(50) 28′ center
(51) 28″ light opening
(52) 38 symmetry rotation axis
(53) 40 reference opening
(54) 42 fuel supply
(55) 44 flame
(56) 46 deflecting device
(57) 48 first edge beam
(58) 50 second edge beam
(59) 52 plane
(60) 54 offset
(61) 56 insulating seal
(62) 58 wall
(63) 60 nozzle
(64) 62 nozzle opening
(65) 64 edge
(66) 66 opening
(67) 68 opening
(68) 70 mica disc
(69) 72 rivet
