EP2657604B1 - Electric ignition device for combustible material in a heating device and heating device with same - Google Patents

Description

The invention relates to an electrical ignition device for fuel in a heating device, as well as a heater equipped therewith, as indicated in the claims 1 and 13.

Known from the prior art is an ignition device to be operated electrically, which is provided by generating a hot air flow for the ignition of solid fuel, such as wood pellets. In this generic ignition device, a heating element, in particular an electrical resistance heater is provided which has arranged in a tubular ceramic body heating elements in the form of resistance lines. The ceramic support body has the required temperature resistance and insulates the electrical resistance leads with respect to electrically conductive peripheral elements. The tubular heating element is inserted in a metallic hollow profile, which forms an outer flow jacket around the tubular heating element. The heating element is on one of its two ends, if necessary detachable, in particular pluggable, supported in a ceramic socket. This socket also serves to make electrical contact with the electrical resistance lines with a power supply to the socket. The arranged inside the metallic hollow profile, ceramic socket for the heating element causes a constriction of the free flow cross-section through the hollow profile, whereby the desired or required air flow rate is only partially achievable. In addition, the positioning accuracy of the heating element with respect to the socket is hardly guaranteed. Unbalanced or unequal flow around the heating element with supply air or ambient air lead to different cooling capacities with respect to the heating element, which can cause performance problems or can lead to increased risk of damage in a particularly unevenly flow around heating element. In addition, the robustness of the electromechanical socket for the heating element is only slightly satisfactory. Mechanical loads on the elongated, tubular heating element can lead to breakage of the plug-in base, which can subsequently lead to a safety impairment due to insulation faults of the plug-in base.

The EP 1 972 853 A1 describes a generic electric ignition device for igniting solid fuels, in particular pellets, wood chips or logs made of wood. This ignition device comprises a protective tube of metal or a metal alloy and at least one electric heating element in the protective tube. The at least one heating element has a ceramic carrier tube and at least one printed on a ceramic foil, electrical heating conductor, wherein the ceramic foil is wrapped around the support tube and sintered with this, that the at least one heat conductor between the ceramic foil and the support tube is arranged. The carrier tube is arranged in the protective tube such that an air flow through the carrier tube can be conducted. According to one embodiment, the heating element is arranged concentrically in the protective tube and fixed by means of a spacer ring in the protective tube. The spacer may completely surround the heating element or be present only in some areas, so that not only an air flow in the support tube, but also in the space between the heating element and the protective tube can be generated.

The present invention has for its object to provide an improved electrical ignition device for fuel in a heater. In particular, it is an object of the present invention to provide an electrical ignition device, which has increased mechanical robustness, has a long-term high ignition performance and ignition reliability and is still possible to produce as inexpensively. A further object of the invention is to provide a heater which can be used as comfortably as possible with high functional reliability.

This object of the invention is achieved by a technically improved ignition device according to claim 1. It is advantageous that the heating element, in particular its ceramic support body, is held reliably and dimensionally stable in the hollow profile. In particular, acting vibrations or shock loads can not lead to a positional deviation of the heating element or the ceramic support body. Due to the impact-resistant fixation of the heating element in the hollow body, a proper flow around and cooling of the heating element with the air to be heated is always ensured. This possibly full or even flow around and cooling of the heating element or the ceramic support body favors its achievable life, so that a long-term functional ignition device can be achieved. In particular, gradual or shock related Deviations of the heating element from the desired position during operation of the ignition device or the heating device for solid fuel equipped with it almost impossible. Another advantage of the measure according to the invention is that the holder of the ceramic support body, starting from its lateral surface, the reduction of the free flow cross-section caused by this support can be reduced to a minimum. As a result, the flow resistance in the air inlet section of the ignition device or the ceramic support body is kept relatively low with respect to the air to be supplied to be heated. By eliminating a ceramic socket for mounting and electrical contacting of the heating element and the cost of producing an electrical ignition device according to the invention can be kept as low as possible. In addition, the specified ignition device provides increased protection against electrical insulation errors, after a brittle, fragile socket for releasably holding and contacting the electrical heating element is unnecessary. In addition, mechanical shock loads can not lead to a deviation of the heating element from the planned position, so that a reliable function and a planned heating or ignition performance is guaranteed.

The advantage here is further that thereby the positional stability or the fixing accuracy and also the holding force of the heating element in relation to the surrounding hollow profile is further improved.

An expedient measure for attaching or attaching the at least one metallic holding element to the ceramic supporting body is specified in claim 2. As a result, a high-strength connection between the ceramic support body and the at least one metallic support element can be established. In particular, this makes it possible to dispense with mountings based on clamping forces or form-locking connections. Furthermore, it is advantageous that such surface coatings do not reduce the cross section of the ceramic support body, so that the risk of a notch breaking effect is minimized or excluded and a high degree of robustness of the heating element is achieved.

An alternative embodiment of metallic fasteners is given in claim 3. This makes it possible to build a stable connection between the ceramic support body and the fastener, without technologically demanding coating process to require for the ceramic substrate for the application of metallic surface layers.

Also advantageous are the measures according to claim 4, as a reliable or temperature-stable connection can be constructed even when using solder joints between the ceramic support body and the metallic support member. In particular, excessive heating of a soldering or joining connection between the holding element and the ceramic support body is thereby held back, so that a reliable connection of the metallic support element to the ceramic support body of the heating element is ensured.

Of particular advantage are also the measures according to claim 5, since characterized the electrical supply lines are fixed directly to the ceramic support body of the heating element, in particular electrically contacted with the resistance lines. Manufacturing technically complex and ultimately filigree plug contacts are therefore unnecessary. The direct welding or soldering with the electrical resistance lines or with low-impedance leads to the electrical resistance lines also the reliability of operation and safety in terms of safety-critical Spannungsbeaufschlagungen of metallic components in the vicinity of the heating element is improved. In particular, this can increase the electrical safety of the ignition device.

Furthermore, the measures according to claim 6 are advantageous since, in particular, when using a cylindrical hollow profile, an exact centering of the heating element in the interior of the hollow profile can be achieved. In addition, the achievable with two opposing support elements stability is so high that even with external force effects the scheduled positioning of the heating element is ensured in the hollow profile. In addition, a reduction of the free flow cross-section in the hollow profile can be kept low.

Also advantageous are the measures according to claim 7, since thereby the free flow cross-section within the hollow profile is hardly or as little as possible affected by the holding elements. In addition, by the selective support of the legs of the Holding bracket on the ceramic support body heat transfer to the headband and subsequently held on the outside surrounding hollow profile hinan or minimized. In addition, a stable support or alignment of the heating element is ensured by the mutually distanced, selective support of the ceramic support body with respect to the headband after this double or multiple support can withstand unilateral force effects or torques improved.

In the measures according to claim 8 is advantageous that the base portion of the headband is spaced to the ceramic support body, so that the heat transfer is kept as low as possible on the outer hollow profile. Another advantage of this design is that the relatively large base portion can be used for stable connection to the hollow profile and also a simple connection between headband and hollow profile is possible.

In the measures according to claim 9 is advantageous that the headband ensure automatic centering of the heating element with respect to the outer hollow profile, so that the assembly or production cost is as low as possible.

The measures according to claim 10, a simple, efficient and high-strength connection between the hollow profile and the inner heating element is created in an advantageous manner.

In this case, a further development according to claim 11 is advantageous, since in this way the expenditure and thus the costs for the production of the ignition device can be kept as low as possible. In particular, this allows a rational assembly or attachment of the heating element within the hollow profile.

Finally, the measures according to claim 12 are also advantageous since the air throughput is sufficiently strong or relatively high even at low suction or low pressure ratios. In particular, one-sided heating or sections of overheating of the heating element are thereby kept in the background, whereby the functional reliability or the achievable duration of use of the ignition device is improved. This is made possible mainly by the need for a separate holding and Kontaktierungssockels or achieved by the specified holder of the ceramic support body via the lateral surface, and achieved by the direct electrical contacting of the resistance lines.

The last-mentioned object of the invention is achieved by a heating device according to claim 13. The achievable advantageous effects and technical effects can be found in the preceding and the following description parts.

For a better understanding of the invention, this will be explained in more detail with reference to the following figures.

Fig. 1

ein Ausführungsbeispiel einer Heizeinrichtung, insbesondere eines Pellets-Ofens mit einer elektrischen Zündvorrichtung für das Brennmaterial;

Fig. 2

den Brennraum einer Heizeinrichtung, welche mit der elektrischen Zündvorrichtung für das Brennmaterial ausgestattet ist;

Fig. 3

eine Ausführungsform der erfindungsgemäßen, elektrischen Zündvorrichtung in perspektivischer Darstellung;

Fig. 4

die Zündvorrichtung gemäß Fig. 3 im Längsschnitt;

Fig. 5

das Heizelement der Zündvorrichtung gemäß Fig. 3 in perspektivischer Ansicht;

Fig. 6

das Heizelement gemäß Fig. 5 in Seitenansicht;

Fig. 7

das Heizelement gemäß Fig. 5 in Ansicht gemäß Pfeil VII in Fig. 6.

In each case, in a highly simplified, schematic representation:

Fig. 1

an embodiment of a heating device, in particular a pellet furnace with an electrical ignition device for the fuel;

Fig. 2

the combustion chamber of a heater equipped with the electric igniter for the fuel;

Fig. 3

an embodiment of the electric ignition device according to the invention in a perspective view;

Fig. 4

the ignition device according to Fig. 3 in longitudinal section;

Fig. 5

the heating element of the ignition device according to Fig. 3 in perspective view;

Fig. 6

the heating element according to Fig. 5 in side view;

Fig. 7

the heating element according to Fig. 5 in view according to arrow VII in Fig. 6 ,

By way of introduction, it should be noted that in the differently described embodiments, the same parts are provided with the same reference numerals or the same component names, wherein the disclosures contained throughout the description are transmitted mutatis mutandis to the same parts with the same reference numerals or component names can. Also, the position information selected in the description, such as top, bottom, side, etc. related to the immediately described and illustrated figure and these position information in a change in position mutatis mutandis to transfer to the new location.

In the Fig. 1 . 2 an embodiment of a heater 1 is illustrated with an electrically operated ignition device 2 for fuel. This heating device 1 is formed by an oven for combustion or combustion of solid fuels, preferably of biomass. In particular, the heating device 1 may be formed by a so-called stove, which, among other things, also meets high aesthetic requirements. The corresponding biomass is preferably formed by pellets, but may also be defined by logs or by wood chips. In principle, the ignition device 2 described in detail below is designed and provided for igniting biomass pellets, in particular wood pellets. After appropriate firing or ignition of pellets or the like via the ignition device 2, it is of course also possible to burn firewood or the like with the heating device 1. In this case, the pellets or other relatively easily inflammable ignition aids in connection with the ignition device 2 to be operated electrically are to be understood as an automated or automatable ignition system.

The heating device 1 serves primarily to provide heat in order to preferably heat living spaces. The corresponding heating device 1 is erected directly in the living area and emits appropriate heat by radiant heat or convective heat into the environment by heating to a corresponding extent the room or ambient air to the heater 1. It is also possible to assign the heater 1 warming trays or baking trays, or to provide heat exchanger elements to allow hot water treatment for heating or service water.

The heating device 1 comprises a substantially cuboidal housing, in which a combustion chamber 3 is formed for combustion of preferably solid fuel based on biomass. The heating device 1 may comprise a supply air control device 5, via which the combustion chamber 3 supplied combustion air is predominantly manually and / or automatically regulated. Furthermore, an unillustrated flue gas blower can be provided, which dissipates the flue gases formed in the combustion chamber 3 by suction and in passing a flue gas fireplace. This flue gas blower also has an influence on the combustion air supply or on the throughput of combustion air via the supply air control device 5.

Preferably, the ignition device 1 is used in conjunction with a heater 1 for the combustion of wood pellets. Such a pellet heating device 1 has, in the combustion chamber 3, as known per se, a receiving recess or a receiving tray 6 for the pellets intended for combustion. The corresponding receiving recess or receiving tray 6 is positioned in the lower portion of the combustion chamber 3. This receiving recess or receiving tray 6 is by means of a fuel delivery device 7, which includes, for example, a sloping pellet chute 8, with the amount of pellets to be burned each chargeable.

The ignition device 2 is associated with the receiving tray 6 and the corresponding receiving recess for fuel within the combustion chamber 3 such that their hot air flow can ignite the intended for combustion pellets. It is useful if a hot air end portion 9 of the ignition device 2 projects directly into the receiving recess or receiving tray 6 for the pellets to be burned.

The ignition device 2 operates according to the hot-air principle, wherein the heated air by means of the ignition device 2 can cause ignition of the fuel, in particular of the pellets, in the receiving recess or receiving tray 6. After ignition of these pellets, it is possible and expedient to deactivate the electrically operated ignition device 2 and to ensure continuity of the combustion process by means of controlled or controlled supply of pellets.

The ignition device 2 thus represents an automatic ignition device for the fuel. The ignition device 2 is based on the hot air principle, ambient or room air is passed through the ignition device 2 and is strongly heated by at least one electric heating element 10, in particular to a temperature from about 300 ° C to 600 ° C is heated. Typically, the temperature of the hot air flow at the outlet side 42 of a manually and / or control technology activatable heating element 10 between about 350 ° C and 450 ° C. This is sufficient to be in the receiving cavity or in the receiving tray 6 located biomass, in particular wood pellets to ignite. It is expedient here to build up the corresponding air flow through the ignition device 2 by means of a negative pressure generated in the combustion chamber 3 compared to the ambient pressure of the heating device 1. Preferably, one of the heater 1 associated, not shown flue gas blower used to generate negative pressure in the combustion chamber 3. In this case, ambient or room air is also sucked through the ignition device 2 and heated by the at least one electric heating element 10. The hot air thus formed subsequently serves to ignite the wood pellets, not shown, located in the receiving recess or receiving tray 6.

In the Fig. 3, 4 an advantageous embodiment of the ignition device 2 is exemplified. This ignition device 2 comprises at least one electrical heating element 10, which has electrical resistance lines 11. These electrical resistance lines 11 represent heating resistors or heating cables which heat when exposed to electrical energy and consequently convert the electrical energy into thermal energy. This represents a fundamental, technological difference to high-voltage ignition devices based on sparks, or to flame ignitors, for example based on combustible gases.

The emanating from the electrical resistance lines 11 thermal energy is used for air heating, especially for hot air generation. The electrical resistance lines 11 are supported on or preferably in a ceramic support body 12. The ceramic supporting body 12 for the resistance lines 11 fulfills not only its carrying or holding function but also an electrical insulation function. In addition, the ceramic support body 12 provides good heat resistance, so that it can also reliably absorb, position and mutually insulate even high-resistance resistor lines 11. In addition, the ceramic supporting body 12 also has an electrical insulating function with respect to peripheral sections or with respect to metallic or electrically conductive components in the vicinity of the ignition device 2.

The electrical heating element 10 of the ignition device 2 thus comprises at least the ceramic support body 12, in which a plurality of electrical resistance lines 11 are cast or received. At least one such heating element 10 is at least Most received in a surrounding or the heating elements 10 outside hollow section 13 and held stable in position or from the hollow section 13.

It is expedient to perform the hollow section 13 tubular, in particular hollow cylindrical. Similarly, it is expedient if the ceramic support body 12 for the resistance lines 11 tubular, in particular hollow cylindrical and concentric with the hollow section 13 is arranged. The hollow section 13 is expediently formed from a metallic material, in particular from stainless steel.

How best of a synopsis of Fig. 3 to 7 can be seen, the heating element 10 and its ceramic support body 12 is supported starting from its lateral surface 14 relative to the hollow profile 13. For this purpose, at least one metallic holding element 15, 16 attached to the lateral surface 14 of the ceramic support body 12, in particular soldered or welded. The at least one retaining element 15, 16 protrudes from the lateral surface 14 of the ceramic support body 12 and thus forms a projection or a survey with respect to the preferably cylindrical lateral surface 14 of the ceramic support body 12. The at least one retaining element 15, 16 is fixedly connected to the hollow profile 13 in a section remote from the ceramic support body 12. In particular, the holding element 15, 16 for the ceramic support body 12 with the hollow section 13 fixed or permanently connected, in particular soldered or welded together. By the at least one holding element 15, 16, wherein preferably two with respect to the lateral surface 14 opposite holding elements 15, 16 are provided, is a rigid or non-destructive non-releasable attachment between the heating element 10 and its ceramic support body 12 and the hollow profile 13 formed. In particular, a rigid, the lateral surface 14 of the ceramic support body 12 relative to the inner surface 17 of the hollow section 13 distancing connection between the ceramic support body 12 and the hollow section 13 is formed, as best of Fig. 4 is apparent. The heating element 12 or its ceramic support body 12 is thus thus via the holding elements 15, 16, which act on the lateral surface 14 of the ceramic support body 12, virtually clamped or penned in the interior of the hollow section 13, in particular relatively directly against the inner surface 17 of the hollow profile 13 supported.

For fixed connection of at least one holding element 15, 16 with the ceramic support body 12, it is expedient if at least in a partial section of the lateral surface 14 of the ceramic support body 12 at least one metallic fastening means 18, 19 is formed, which for permanent connection, in particular for welding or Soldering with the metallic holding element 15, 16 is provided.

According to an advantageous embodiment, it is provided to form the metallic fastening means 18, 19 by at least one metallic surface layer 18 ', 19' on the ceramic support body 12, as shown in the Fig. 5, 6 is apparent. This metallic surface layer 18 ', 19' is applied to the surface of the ceramic material of the support body 12. The metallic surface layer 18 ', 19' is limited to the immediate vicinity of the holding elements 15, 16. For applying any known from the prior art method for coating ceramic materials can be used. For example, a metal vapor deposition method or a layered burn-in of different metal layers is applicable. The metallic surface layers 18 ', 19' thereby represent a type of soldering pads or welding zones on the ceramic of the heating element 10 or the support body 12. A layer thickness of the surface layers 18 ', 19' is typically less than 0.5 mm, in particular only a few hundredths of a millimeter.

According to an alternative embodiment, it is possible to partially integrate or encapsulate at least one metallic fastening means 18, 19 in the ceramic carrier material, in particular in the ceramic substrate of the carrier body 12. The integration of the metallic fastener 18, 19 in the ceramic support body 12 is provided such that a portion of the surface of the metallic fastener 18, 19 terminates approximately flush with the lateral surface 14 of the support body 12, as in Fig. 4 was illustrated. Optionally, a relative to the lateral surface 14 slightly recessed or raised trained arrangement of surface portions of the metallic fastening means 18, 19 may be provided. It is essential that the fastening means 18, 19 implemented in the ceramic supporting body 12 or the surface layer 18 ', 19' applied to the ceramic form a connection point or a type of soldering pad for welding or soldering to the metallic holding element 15, 16. Alternatively, it is also possible that at least one holding element 15, 16 in the ceramic substrate of the support body 12 partially integrate or pour and thereby dispense with separate fasteners 18, 19.

The ceramic support body 12 can be made elongated or rod-shaped, in particular tubular or hollow cylindrical. It is useful when the ceramic support body 12 within a first longitudinal section 20, the at least one metallic support member 15, 16 and within a second longitudinal section 21 forms a heating section 22. In this heating section 22, a comparatively high areal density of electrical resistance lines 11 is provided, so that a comparatively higher heat development occurs in the heating section 22 of the ceramic support body 12 when exposed to electrical energy than in the first longitudinal section 20, in which the at least one holding element 15, 16 is positioned is. It is expedient if the second longitudinal section 21, in particular the heating section 22 occupies between 30% to 60%, preferably in about 40% to 50% of the total length of the ceramic support body 12. In particular, it is expedient if the heating section 22 amounts to only about half the length of the supporting body 12. The remaining portion of the ceramic support body 12 is defined by the first longitudinal portion 20, in which the holding element 15, 16 and the metallic fastening means 18, 19 for the at least one holding element 15, 16 is positioned.

Electrical supply lines or supply lines 23, 24 for the heating element 10 are preferably also in a remote from the heating section 22 or distant end portion of the support body 12 with the respective electrical resistance lines 11 fixed, in particular welded or soldered. In particular, ends of the supply lines 23, 24 or of a power cable are connected directly to the heating element 10, preferably soldered or welded to connection contacts 25, 26 of the resistance line 11. The connection contacts 25, 26 are preferably formed by solder pads, which are preferably accessible from the lateral surface 14 of the ceramic support body 12 and thereby electrically contacted with the ends of the respective supply lines 23, 24, preferably can be soldered.

For operating the ignition device 2 or the heating element 10, electrical low voltage, in particular the mains voltage present in households of preferably 230 V AC, or optionally of 400 V AC, is provided. In particular, the electrical resistance lines 11 of the heating element 10 by applying standard or in households usual mains voltage heated so that can be ignited with the guided and sucked by the igniter 2 airflow particulate biomass in the form of wood pellets.

According to an expedient embodiment, as described in the Fig. 5 to 7 is illustrated, two with respect to the lateral surface 14 of the ceramic support body 12 opposite holding elements 15, 16 may be formed. These holding elements 15, 16 can be formed by longitudinally section C- or U-shaped headband 27, 28. These with respect to their longitudinal section C- or U-shaped headband 27, 28 are aligned parallel to the longitudinal extent of the ceramic support body 12. Legs 29, 30 of these brackets 27, 28 are supported selectively on the lateral surface 14 of the support body 12. In particular, the legs 29, 30 of the headband 27, 28 with the integrated in the ceramic support body 12, metallic fasteners 18, 19 and with the applied on the ceramic support body 12, metallic surface layers 18 ', 19' soldered or welded.

A leg portion 29, 30 connecting base portion 31 of the headband 27, 28 is arranged by the selective support of the legs 29, 30 with respect to the lateral surface 14 of the ceramic support body 12 at a distance. In the installed state of the heating element 10 and the ceramic support body 12, at least a portion of the base portion 31 of the metallic support bracket 27, 28 contacted with the inner surface 17 of the hollow section 13, as best of Fig. 4 is apparent. When not installed or unloaded - Fig. 5 In this case, the base portion 31 may be slightly arcuately curved, so that the retaining clips 27, 28 exert a resilient bias relative to its inner surface 17 in the inserted into the hollow section 13 of the heating element 10 and thereby achieve a tolerance compensation or a mounting relief and / or a thermal expansion compensation can.

The longitudinal section C- or U-shaped headband 27, 28 can also center the ceramic support body 12 in the interior 32 of the outer or outer surrounding hollow profile 13. In addition, the two brackets 27, 28 support the ceramic support body 12 in the radial direction relative to the inner surface 17 of the hollow profile 13 substantially free of play from. As an alternative to a double arrangement of holding elements 15, 16 or retaining clips 27, 28, it is of course possible to provide three retaining clips distributed over the circumference of the ceramic supporting body 12.

It is practicable if the at least one metallic holding element 15, 16 is welded via at least one opening 33, 34 in the outer boundary wall 35 of the hollow profile 13 with the hollow profile 13 formed from a metallic material. In particular, the at least one opening 33, 34 may be formed in the hollow profile 13 by at least one through hole through the opposite boundary walls 35 of the metallic hollow section 13. This allows two opposing metallic support members 15, 16 on the ceramic support body 12 in a simple manner by means of a in the apertures 33, 34 mounted spot weld 36, 37 are rigidly connected or fixed to the metallic hollow section 13, as in Fig. 4 has been illustrated schematically.

It is advantageous to make the ceramic support body 12 tubular, in particular hollow-cylindrical, so that it forms an inner air heating duct 38. How best from a synopsis of Fig. 4 and 7 can be seen by the specified construction or attachment a free cross-sectional area 39 for an air inlet at the inlet side 40 in the ceramic support body 12 at least approximately the same size, as a free cross-sectional area 41für the outlet of heated or heated air at the opposite In particular, the free cross-sectional area 39 at the inlet side 40, neglecting the possibly occurring, minimal reduction of the free flow cross-section through the supply lines 23, 24, identical to the free cross-sectional area 41 on the outlet side 42 of the ceramic support body 12th an unobstructed air flow through the ceramic, tubular support member 12 can be ensured. This is achieved primarily by the previously described holder or by the baseless attachment of the ceramic support body 12 via the lateral surface 14.

According to a first embodiment of the ignition device 2, the ceramic support body 12 of the heating element 10 can be positioned with its two opposite ends within the two longitudinal ends of a one-piece hollow profile 13 be. After the heating element 10 or its ceramic support body 12 is fastened permanently or non-detachably in the hollow profile 13, direct access to the ceramic support body 12 can be prevented or eliminated. In particular, it is not necessary to make the fixed heating element 10 integrated in the hollow profile 13 accessible or accessible after an exchange thereof is not expedient or intended.

According to one in Fig. 4 illustrated, optional embodiment, the hot air end portion 9 of the ignition device 2 may be formed by a tubular attachment 43 on the hollow section 13. This attachment part 43 constitutes an extension for the tubular hollow profile 13 and is preferably plugged onto the end of the hollow profile 13 closest to the heating section 2 or pressed against detachment. This attachment part 43 can also be designed to be tapered in accordance with a possible development, so that it unfolds a nozzle effect and concentrates the heat released by the heating element 10 or the air flow guided by the ignition device 2. In particular, the attachment 43 can act as a hot air nozzle, which concentrates the exiting hot air and thereby positively influences the ignition characteristics of the ignition device 2. This optional attachment 43 is preferably made of a material which has an increased heat resistance, in particular a higher heat resistance, than the metallic hollow profile 13. The attachment 43 may be formed by a ceramic material or by a high temperature resistant, metallic material to then, when the attachment 43 extends over a longer period of time in a Glutansammlung to achieve improved heat resistance and increased life. The basic function of this attachment 43 is thus to improve the robustness or heat resistance of the ignition device 2.

At the opposite end of the hot air end portion 9 of the ignition device 2, a fastening device 44, in particular a holding plate 45 is provided. Thus, the ignition device 2 can be firmly or reliably fixed in the heating device 1 or in a combustion chamber 3. The holding plate 45 can be spaced at a distance 46 of 3 mm to 20 mm, preferably in about 10 mm from the end of the hollow section 13. The ignition device 2 is installed horizontally or approximately horizontally in the heating device 1 in relation to the longitudinal axis of the hollow profile 13.

According to an advantageous embodiment, the hot air end portion 9 opposite, frontal end of the hollow section 13 is closed as airtight as possible. In contrast, in a vicinity of the fastening device 44 or retaining plate 45, in particular in a section between the fastening device 44 and the hot air end 9, at least one Lufteintrittsöffhung 47, 48 is formed on which to be heated supply air or ambient air 49 in the ignition device 2, in particular whose hollow profile 13 can flow. These air inlet openings 47, 48 are preferably formed by a radial through hole through the hollow section 13. The ambient air 49, which preferably flows in by negative pressure into the ignition device 2 or into the interior 32 of the hollow profile 13, is then strongly heated by the heating element 10 supplied with electrical energy and then exits the ignition device 2 as hot air flow 50 at the hot air end section 9.

The embodiments show possible embodiments of the ignition device 2 and the heater 1, wherein it should be noted at this point that the invention is not limited to the specifically illustrated embodiments thereof, but also various combinations of the individual embodiments are mutually possible and this variation possibility due to Teaching for technical action by objective invention in the skill of those working in this technical field is the expert. So are all conceivable embodiments, which are possible by combinations of individual details of the illustrated and described embodiments, of the scope of protection.

For the sake of order, it should finally be pointed out that, for a better understanding of the structure of the ignition device 2, these or their components have been shown partly unevenly and / or enlarged and / or reduced in size. <B> Reference Numbers </ b> 1 heater 36 Spot weld 2 detonator 37 Spot weld 3 combustion chamber 38 Air heating channel 4 Combustion chamber base plate 39 Cross-sectional area 5 Zuluftsteuervorrichtung 40 entry page 6 receiving dish 41 Cross sectional area 7 Fuel delivery device 42 exit side 8th Pelletsschurre 43 attachment 9 Heißluftendabschnitt 44 fastening device 10 heating element 45 Retaining plate 11 resistance line 46 distance 12 supporting body 47 Air inlet opening 13 hollow profile 48 Air inlet opening 14 lateral surface 49 ambient air 15 retaining element 50 Hot air stream 16 retaining element 17 palm 18 fastener 18 ' surface layer 19 fastener 19 ' surface layer 20 longitudinal section 21 longitudinal section 22 heating section 23 supply line 24 supply line 25 connection contact 26 connection contact 27 headband 28 headband 29 leg 30 leg 31 base section 32 inner space 33 breakthrough 34 breakthrough 35 boundary wall

Claims (13)

1. An electric ignition device (2) for combustible material in a heating device (1), comprising an electric heating element (10) with a ceramic support (12), wherein electrical resistors (11) are supported in/at said ceramic support (12), said heating element (10) at least predominantly housed in a hollow profile (13) surrounding the exterior of the heating element (10) and supported in the hollow profile (13), characterized in that a metallic fastener (18, 19) is formed on the ceramic support (12), wherein a metallic retaining element (15, 16) is fastened, in particular is soldered or welded, to the exterior surface (14) of the ceramic support (12) via said metallic fastener (18, 19), wherein at least one metallic retaining element (15, 16) protrudes from the exterior surface (14) of the ceramic support (12) and wherein said at least one protruding retaining element is firmly connected, in particular is soldered or welded, to the hollow profile (13) in a section facing away from the ceramic support (12), such that a rigid connection is formed between the ceramic support (12) and the hollow profile (13), which spaces the exterior surface (14) of the ceramic support (12) apart from the interior surface (17) of the hollow profile (13), and that ambient air (49) flowing into an interior space (32) between the hollow profile (13) and the heating element (10) and flowing past the at least one retaining element (15, 16) is heated when the heating element (10) is supplied with electric energy, wherein said ambient air (49) subsequently exits the ignition device (2) at a hot-air end portion (9) in the form of a hot air stream (50).
2. The ignition device according to claim 1, characterized in that at least one metallic fastener (18, 19) is formed on the ceramic support (12) by at least one metallic surface layer (18', 19'), wherein the metallic surface layer (18', 19') is applied to the ceramic material of the support (12).
3. The ignition device according to claim 1, characterized in that at least one metallic fastener (18, 19) is partially integrated or partially moulded into the ceramic substrate of the support (12), such that a partial section of the surface of the metallic fastener (18, 19) fits approximately flush with the exterior surface (14) of the ceramic support (12).
4. The ignition device according to claim 1, characterized in that the ceramic support (12) is designed in the shape of a rod, in particular tubular, wherein said support (12) includes at least one metallic fastener (18, 19) for the at least one retaining element (15, 16) within a first longitudinal section (20) and a heating section (22) within its second longitudinal section (21), said heating section (22) comprising serpentine, electrical resistors (11).
5. The ignition device according to claim 4, characterized in that electrical supply cables (23, 24) for the heating element (10) are welded or soldered to the electrical resistor cables (11) or to low-impedance feeds to the electrical resistor cables (11) in an end section of the ceramic support (12) facing away from the heating section (22).
6. The ignition device according to one of the preceding claims, characterized in that two retaining elements (15, 16) are provided, said retaining elements (15, 16) being positioned opposite to each other in reference to the exterior surface (14) of the ceramic support (12) and each retaining element (15, 16) being formed by brackets (27, 28), which are C-shaped or U-shaped in their longitudinal sectional view.
7. The ignition device according to claim 6, characterized in that the brackets (27, 28), which are C-shaped or U-shaped in their longitudinal sectional view, are oriented parallel to the longitudinal extension of the ceramic support (12) and that their legs (29, 30) rest on spots of the at least one metallic fastener (18, 19) of the ceramic support (12).
8. The ignition device according to claim 7, characterized in that a base section (31) of the brackets (27, 28), which connects the legs (29, 30), is arranged at a distance to the exterior surface (14) of the ceramic support (12), said base section (31) making contact with the interior surface (17) of the hollow profile (13).
9. The ignition device according to claim 6, characterized in that the brackets (27, 28), which are C-shaped or U-shaped in their longitudinal sectional view, centre the ceramic support (12) in the interior space (32) of the outer hollow profile (13) and brace the same against the interior surface (17) of the hollow profile (13) in a radial direction.
10. The ignition device according to one of the preceding claims, characterized in that the hollow profile (13) is formed from a metallic material and that at least one metallic retaining element (15, 16) is welded to the hollow profile (13) via at least one opening (33, 34) in the exterior surrounding wall (35) of the hollow profile (13).
11. The ignition device according to claim 10, characterized in that the at least one opening (33, 34) is formed by at least one drill hole in opposing surrounding walls (35) of the metallic hollow profile (13), and that the at least one metallic retaining element (15, 16) of the ceramic support (12) is rigidly and firmly connected with the metallic hollow profile (13) via a spot weld connection (36, 37) provided in at least one opening (33, 34).
12. The ignition device according to one of the preceding claims, characterized in that the ceramic support (12) is designed tubular and thereby forms an interior air heating channel (38), wherein an open cross-sectional area (39) for an air entry at the entry side (40) to the ceramic support (12) at least approximately corresponds to an open cross-sectional area (41) for an exit of heated air at the opposing exit side (42) of the ceramic support (12).
13. A heating device (1) with an electric ignition device (2) for combustible material, comprising a combustion chamber (3), a combustible-material conveyance device (7) and a depression or receptacle (6) for receiving solid combustible material, in particular wood pellets, characterized in that it comprises an ignition device (2) according to one or a plurality of the preceding claims.

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