JP2018523080A - Porous fuel processing element - Google Patents

Abstract

  The present invention relates to an evaporative burner porous fuel treatment element comprising at least one layer (8) formed by fibers (10). Said fibers (10) comprise basalt fibers.

Description

  The present invention relates to an evaporative burner porous fuel treatment element having at least one layer formed from fibers.

  Apart from the spray burner, which is used to some extent as well, an evaporative type in which the liquid fuel is evaporated and subsequently processed to form a fuel / air mixture with the supplied combustion air and subsequently reacted in an exothermic reaction Burners are often used, especially in the case of mobile heating devices that are operated using liquid fuel, such as those used as fixed or auxiliary heaters in vehicles. Especially when used in vehicles, fuels that are also used to operate the internal combustion engines of vehicles, in particular diesel oil, gasoline, ethanol, etc., are often used as liquid fuels.

  In this type of evaporative burner, typically liquid fuel is first fed to a porous fuel processing element that serves to store, distribute and evaporate the fuel. In particular, a plurality of porous fuel processing elements can also be provided, which in each case are adapted to these various functions.

  WO 2012/155897 A1 describes an evaporator assembly for an evaporative burner for a mobile heating device, in which the evaporating element has at least one layer of a metal fabric made of interwoven metal wires. Furthermore, it is described for example to provide a multilayer structure in which a layer of metallic fabric is combined with a further layer of metallic nonwoven.

  It is an object of the present invention to provide an improved porous fuel processing element, an improved evaporative burner, and an improved heating system.

  This object is achieved by a porous fuel processing element according to claim 1. Advantageous refinements are described in the dependent claims.

  The porous fuel treatment element for an evaporative burner has at least one layer formed from fibers. These fibers include basalt fibers. Here, the fibers of the at least one layer can in particular be formed, for example, from basalt fibers. However, it is also possible, for example, that there are further fibers separate from the basalt fibers. Here, the entire fuel treatment element can be formed, for example, from basalt fibers, or at least from one or more layers comprising basalt fibers. However, for example, the porous fuel processing element may further have one or more layers that do not contain any basalt fibers.

  Compared to the fiber materials traditionally used for porous fuel processing elements, basalt fibers have considerable advantages for this application. For example, compared to glass fibers or asbestos fibers, basalt fibers have excellent physical, mechanical, and chemical properties for use in porous fuel processing elements. Basalt fiber is very strong but nevertheless treated in a simple manner, in particular felt, non-woven fabric, needle mat, scrim, woven fabric, warp / weft knitted fabric, knitted fabric or braided fabric etc. This is a flexible fiber material that can form a flat cloth structure. Since the basalt fiber has a very high heat resistance, especially when compared to conventional materials such as metal nonwovens and metal woven fabrics, this material also has a particularly high operating temperature. Suitable for possible evaporation burners. Furthermore, a high storage effect or buffering effect can be provided respectively for liquid fuels that have a low tendency to form deposits and that have not yet evaporated. Furthermore, it is a very cost-effective material that is not dangerous for health.

  According to one refinement, the at least one layer comprises a planar fabric structure, in particular a felt, a nonwoven fabric, a needle mat, a scrim, a woven fabric, a warp / weft knitted fabric, a knitted fabric or a braided fabric. In this case, the characteristics of the fuel processing element can be determined in advance so as to be very aimed by selecting a planar fabric structure. Furthermore, it is also possible to combine different types of planar fabric structures with each other, for example, by combining one or more layers of non-woven fabric and one or more layers of woven fabric.

  According to one improvement, the fibers of the planar fabric structure have a diameter distribution in the range of 5 μm to 35 μm. In this case, the fiber diameter distribution is very positively determined so that the characteristics of the fuel treatment element can be set as intended. Furthermore, positively determining the diameter distribution in this way ensures that there are no health risks when handling the fibers.

  In particular, if the fibers have a length of at least 150 μm, preferably a length of at least 200 μm, it can be ensured in particular that they do not pose a health hazard during handling. It is particularly preferred that the basalt fibers in the case of porous fuel treatment elements exist as very long, so-called endless fibers, which can be produced by known techniques.

  According to one improvement, the porous fuel processing element can comprise at least one layer of basalt wool. The at least one layer mentioned above may in particular comprise basalt wool, or alternatively, additionally provided with one or more further layers, for example comprising basalt wool or formed from basalt wool Can do. By using basalt wool, particularly cost-effective production is possible.

  According to one improvement, the porous fuel processing element has at least one further layer formed from fibers. It is preferred that at least one further layer of fibers can also comprise basalt fibers. In this case, a design embodiment that is particularly advantageous in terms of heat resistance is provided. Alternatively, however, it is also possible, for example, that at least one further layer respectively comprises other fibers, such as in particular metal fibers or metal wires.

  According to one improvement, at least one layer of fibers has a glass-type amorphous structure.

  According to one improvement, the fibers of at least one layer are interconnected by sintering. In this case, an embodiment of a particularly robust and dimensionally stable processing element is possible, which makes it easy to handle during assembly of the evaporative burner. Furthermore, in this case, it is possible to dispense with the addition of a separate support structure that would require additional costs and effort.

  According to one improvement, the fibers are formed by fiber bundles, multifilaments and / or rovings.

  This object is also achieved by an evaporative burner for a mobile heating device operated by liquid fuel having such a porous fuel treatment element.

  This object is further achieved by a heating device having an evaporative burner having such a porous fuel processing element.

  Further advantages and improvements can be obtained from the following description of exemplary embodiments with reference to the accompanying drawings.

1 is a schematic view of a portion of an evaporative burner having a porous fuel processing element according to one embodiment in a fuel operated mobile heating device. FIG. It is the schematic of the evaporator accommodation tool which has a fuel processing element by the 1st modification of embodiment. It is the schematic of the evaporator accommodation tool which has a fuel processing element by the 2nd modification of embodiment. It is the schematic of the evaporator accommodation tool which has a fuel processing element by the 3rd modification of embodiment. It is the schematic of the evaporator accommodation tool which has a fuel processing element by the 4th modification of embodiment. It is the schematic of the evaporator accommodation tool which has a fuel processing element by the 5th modification of embodiment. It is a figure of the fuel processing element by 1st Embodiment. It is a figure of the fuel processing element by 2nd Embodiment. 1 is a schematic view of various planar fabric structures that can be applied to a fuel processing element. FIG. 1 is a schematic view of various planar fabric structures that can be applied to a fuel processing element. FIG. 1 is a schematic view of various planar fabric structures that can be applied to a fuel processing element. FIG. 1 is a schematic view of various planar fabric structures that can be applied to a fuel processing element. FIG. 1 is a schematic view of various planar fabric structures that can be applied to a fuel processing element. FIG. 1 is a schematic view of various planar fabric structures that can be applied to a fuel processing element. FIG. 1 is a schematic view of various planar fabric structures that can be applied to a fuel processing element. FIG. It is a schematic exploded view explaining arrangement | positioning of the fuel processing element in an evaporator accommodation tool. It is a schematic exploded view explaining arrangement | positioning of the fuel processing element in the evaporator container in the case of a modification.

  Hereinafter, the first embodiment will be described in more detail with reference to FIG.

  In FIG. 1, the area | region of the evaporator accommodation tool 2 and the burner cover 3 of the evaporation type burner 1 for movable heating apparatuses is shown roughly. FIG. 1 is a schematic view in a plane including the main axis Z of the evaporative burner. The evaporative burner can be substantially rotationally symmetric with respect to the main axis Z, for example. The evaporative burner 1 can be configured, for example, for a vehicle heating device, in particular an auxiliary heater or a vehicle fixed heater. The evaporative burner 1 here is particularly configured to convert a mixture of evaporated fuel and combustion air, ie a fuel / air mixture, while releasing heat in the combustion space 4. This conversion here can take place in particular with flame-generated combustion, although partial or complete catalytic combustion is also possible. The released heat is transferred in a heat exchanger (not shown) to a medium to be heated, such as air or a coolant. In the schematic diagram of FIG. 1, in particular, a heat exchanger, a discharge for high-temperature combustion exhaust gas, a combustion air delivery device (for example, a blower), a fuel delivery device (for example, a metering pump), an evaporation provided in the same way The control unit for operating the burner is not shown. These components are well known and are described in detail in the prior art.

  The evaporative burner 1 has an evaporator housing 2 in which a porous fuel processing element 5 is disposed. In the case of the exemplary embodiment, the evaporator housing 2 is generally bowl-shaped. The fuel processing element 5 is received in a bowl-shaped recess of the evaporator housing 2 and is fixedly held therein, in particular, for example by welding, brazing / soldering, clamping or using a suitable fixing element. Can. In the following, a design embodiment of the fuel treatment element 5 will be described in more detail.

  A fuel supply line 6 for supplying liquid fuel to the fuel processing element 5 is provided. The fuel supply line 6 opens into the evaporator housing 2 and is connected to a fuel delivery device (not shown) capable of delivering a predetermined amount of liquid fuel through the fuel supply line 6 as schematically indicated by an arrow F. Connected. The fuel supply line 6 is fixedly connected to the evaporator housing 2, for example by welding or brazing / soldering.

  The combustion space 4 is bounded on the outer peripheral side by a combustion chamber 7 that can be formed by, for example, a substantially cylindrical heat-resistant steel component. A plurality of holes 7 a are provided in the combustion chamber 7, so that combustion air can be supplied to the combustion space 4 as schematically indicated by arrows in FIG. 1. The hole 7a here is a part of the combustion air supply portion L through which combustion air is supplied to the side of the fuel processing element 5 opposite to the fuel supply line 6.

  The evaporative burner 1 is configured such that during operation, liquid fuel can be supplied to the fuel processing element 5 via the fuel supply line 6. On the one hand, due to the many cavities, fuel distribution over the entire width of the fuel processing element 5 takes place in and on the fuel processing element 5, and on the other hand, on the side facing the combustion space 4, fuel evaporation or volatilization. Is done. In the case of the illustrated embodiment, the cross-sectional shape of the fuel processing element 5 is substantially circular, and the main axis Z of the evaporative burner 1 passes through the center of the circular cross-sectional shape. However, the cross-sectional shape of the fuel processing element 5 may be other shapes.

  The combustion burner 1 is configured in such a way that the evaporation or volatilization of the liquid fuel takes place in and on the fuel processing element 5 respectively, but the evaporated fuel only when leaving the fuel processing element 5, i.e. the combustion space. Only on the side is mixed with the supplied combustion air to form a fuel / air mixture. Accordingly, the supply of liquid fuel and the supply of combustion air are performed on different sides of the fuel processing element 5. The conversion in the exothermic reaction of the fuel / air mixture here takes place in the combustion space 4 downstream rather than in the fuel processing element 5. Thus, during operation of the evaporative burner 1, there is liquid fuel and fuel vapor in the fuel processing element 5, and potentially inherent air is expelled from the fuel processing element 5 by each evaporation or volatilization process.

  In the case of the exemplary embodiment schematically shown in FIG. 1, the fuel processing element 5 is a structure having a plurality of functional regions, which in the illustrated example is the first region B1, The structure is partially divided into a second region B2 having a structure different from the structure of the first region B1. In the case of this exemplary embodiment, the second region B <b> 2 is disposed so as to face the fuel supply line 6, and the first region B <b> 1 is disposed so as to face the combustion space 4.

  In the case of the first variant of the embodiment schematically shown in FIG. 2a), the fuel processing element 5 does not have a plurality of different functional areas, but only one of the first areas B1.

  In the case of the second variant of the embodiment schematically shown in FIG. 2b), the fuel processing element 5 has a stepped design with a total of three regions B1, B2, B3, the evaporator housing 2 being Configured to correspond. In such a case, for example, the different regions B1, B2, B3 can be configured as intended for the various functions of the fuel processing element 5. For example, the second region B2 can be optimized for fuel delivery by capillary forces and for temporary fuel storage, and the third region B3 can be optimized for lateral fuel distribution. And can serve to make up for tolerances, and the first region B1 can be optimized for fuel evaporation or volatilization, respectively. Here, the different regions B1, B2, B3 can be different from one another, in particular with regard to their structure, configuration, material, and / or thickness, etc.

  Further possible design embodiments of the fuel treatment element 5 having a plurality of functional areas B1, B2, B3 are schematically shown in FIGS. 3a, 3b and 3c. In FIGS. 3 a, 3 b and 3 c, the fuel supply line 6 and further components are also not shown, but it is understood that these further components are also present in each of these further variations. The

  Below, the structure of the fuel processing element 5 which can be used in the case of the above-mentioned embodiment and modification is demonstrated in detail. The design embodiment in this case described below can be used for each one of the regions B1, B2, and B3, especially when only one such region is provided. be able to.

  FIG. 4 shows a layer 8 formed of fibers 10 of the porous fuel processing element 5 according to the first embodiment. The layer 8 in this embodiment is formed from a woven fabric, and the fibers 10 of the woven fabric comprise basalt fibers. In the case of the particular embodiment shown, the woven fabric here is formed by inter alia basalt fibers interwoven. In the case of a porous fuel processing element 5 having one or more further layers 9, the further layer 9 can also be formed, for example, from such a woven fabric. The fibers 10 in the formed layer 8 can be fiber bundles, multifilaments or rovings, respectively.

  FIG. 5 shows a layer 8 formed from fibers 10 of a porous fuel processing element 5 according to a second embodiment. The layer 8 in the case of the second embodiment is formed as a nonwoven fabric containing basalt fibers. In the case of the particular embodiment shown, the woven fabric here is formed in particular by basalt fibers. In the case of a porous fuel processing element 5 having one or more further layers 9, the further layer 9 can also be formed, for example, from such a nonwoven fabric. Furthermore, in the fuel processing element 5, for example, one or more layers of such a nonwoven fabric can be combined with one or more layers of the above-mentioned woven fabric.

  Further, in the porous fuel processing element 5, one or more layers may be configured as a planar fabric structure as schematically described below with reference to FIGS. 6a) to 6g). It should be noted here that, in particular, planar fabric structures such as these can be used in the porous fuel processing element in any combination.

  Various embodiments of at least one layer 8 (or optionally also each of the further layers 9) of the porous fuel processing element 5 are shown in FIGS. 6a) to 6g). These various embodiments have the common element that in each case the fibers 10 comprise basalt fibers. In particular, the fibers 10 can be formed by basalt fibers in each case.

  FIG. 6a) shows a schematic view of the nonwoven as a planar fabric structure for each of the layers 8 or 9, which has also been described with reference to FIG.

  FIG. 6b) shows a schematic view of an alternative in which the planar fabric structures for layers 8 or 9 are each formed by felt.

  FIG. 6c) shows a schematic view of a planar fabric structure formed as a woven fabric of basalt fibers for each of layers 8 or 9, which has also been described with reference to FIG.

  FIG. 6d) schematically shows the configuration of each layer 8 or 9 as a knitted fabric. FIG. 6e) schematically shows the configuration of each layer 8 or 9 as a braid. FIG. 6f) schematically shows the configuration of each layer 8 or 9 as a warp / weft knitted fabric. FIG. 6g) schematically shows the configuration of each layer 8 or 9 as a scrim.

  It should be noted that the various planar fabric structures described by FIGS. 6 a) to 6 g) can be combined with each other in almost any manner in the porous fuel processing element 5. In the case of the above-described planar fabric structure, the fibers 10, ie the basalt fibers in the case of certain design embodiments, have a very dense diameter distribution with a diameter between 5 μm and 35 μm, and the fibers A length of 10 is preferably longer than 200 μm in each case, but it is particularly advantageous if it is longer than 150 μm. The fiber 10 in this case is particularly preferably in the form of a so-called endless fiber, for example. Here, the fiber 10 has an amorphous glass type structure. It is preferable that the surface of the fiber 10 can be glued at the time of manufacture so as to improve the processability.

  Instead of or in addition to the planar fabric structure described above, the layers 8 or 9 can also each contain basalt wool, thereby enabling a particularly cost-effective production.

  The incorporation of the above-described fuel treatment element 5 and at least one layer 8 or 9 containing basalt fibers into the evaporator assembly of the evaporative burner 1 is briefly described below with reference to the schematic exploded view of FIG. To do.

  As schematically shown in FIG. 7, the above-described fuel processing element 5 is disposed in a bowl-shaped depression of the evaporator housing 2. In order to ensure sufficient mechanical stability even at high temperatures for long periods of time, a support structure 11, which can be formed in particular by a heat-resistant metal mesh or metal woven fabric, is provided on the combustion space side of the fuel processing element 5. It is attached. The fuel processing element 5 and the support structure 11 are fastened in the evaporator housing 2 by a mounting ring 12. Here, the mounting ring 12 can in particular be configured in a manner known per se as a retaining ring that is fastened or supported on the evaporator housing 2, or the mounting ring 12 and the evaporator housing 2 Can be connected, for example, by welding or brazing / soldering. The evaporator assembly thus formed can then be easily incorporated into the evaporative burner 1.

Variation In the variation of the above-described embodiment, the mechanical stability of the porous processing element 5 is enhanced by interconnecting the fibers 10 by sintering. In this method, a fixed connection is formed between the fibers at the point where the fibers 10 intersect. Sintering in this case can be carried out by a pure thermal process in which the connection is made, for example only by raising the temperature and optionally in addition to compressing the fibers 10. However, as an alternative to such a pure thermal process, it is also possible to accelerate the sintering process, for example by means of a chemical process in which further binder / sintering additives are added to the fibers.

  As shown schematically in FIG. 8, this modification enhances the mechanical stability of the fuel processing element 5 so that the additional support structure 11 can be omitted in the assembly of the evaporator assembly. it can.

Claims (13)

Having at least one layer (8) formed from fibers (10);
The fibers (10) comprise basalt fibers;
A porous fuel processing element (5) for the evaporative burner (1).   The porous fuel processing element according to claim 1, wherein the at least one layer is a planar fabric structure.   The porous fuel processing element according to claim 2, wherein the planar fabric structure is felt, nonwoven fabric, needle mat, scrim, woven fabric, warp / weft knitted fabric, knitted fabric, or braided fabric.   4. The porous fuel processing element according to claim 1, wherein the fibers (10) of the planar fabric structure have a diameter distribution in the range of 5 μm to 35 μm.   5. The porous fuel processing element according to claim 1, wherein the fibers (10) have a length of at least 150 μm, preferably a length of at least 200 μm.   The porous fuel processing element (1) according to any of the preceding claims, wherein the porous fuel processing element (5) comprises at least one layer (8, 9) of basalt wool.   7. A porous fuel processing element according to any one of the preceding claims, having at least one further layer (9) formed from fibers (10).   The porous fuel processing element according to claim 7, wherein the fibers (10) of the at least one further layer (9) also comprise basalt fibers.   The porous fuel processing element according to any one of claims 1 to 8, wherein the fiber (10) has a glass-type amorphous structure.   10. The porous fuel processing element according to any one of the preceding claims, wherein the fibers (10) of the at least one layer (8) are interconnected by sintering.   11. A porous fuel processing element according to any one of the preceding claims, wherein the fibers (10) are formed by fiber bundles, multifilaments and / or rovings.   12. An evaporative burner (1) for a mobile heating device operated by liquid fuel, comprising the porous fuel processing element (5) according to any one of the preceding claims.   A heating device comprising an evaporative burner (1) comprising a porous fuel treatment element (5) according to any one of the preceding claims.

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