EP3320263A1

EP3320263A1 - Porous fuel treatment element

Info

Publication number: EP3320263A1
Application number: EP16736777.0A
Authority: EP
Inventors: Klaus MÖSL; Peter Neidenberger; Volodymyr Ilchenko; Bengt Meier
Original assignee: Webasto SE
Current assignee: Webasto SE
Priority date: 2015-07-06
Filing date: 2016-06-14
Publication date: 2018-05-16
Also published as: RU2683006C1; CN107850297A; KR102171137B1; KR20180021162A; DE102015110828A1; US20180202651A1; CN107850297B; DE102015110828B4; JP2018523080A; WO2017005240A1; JP6751899B2

Abstract

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

Description

Porous fuel processing element

The present invention relates to a porous fuel treatment element for an evaporator burner with at least one fiber-formed layer.

In mobile, operated with liquid fuel heaters, such as are used in particular as auxiliary heaters or auxiliary heaters in vehicles, often also used next atomizer burners evaporator burner are used in which the liquid fuel evaporates, then with supplied combustion air to a fuel-air Mixture prepared and then reacted in an exothermic reaction. In particular, when used in vehicles often comes as a liquid fuel of the fuel used, which is also used to operate an internal combustion engine of the vehicle, in particular, for example. Diesel, gasoline, ethanol and the like.

In such evaporator burners, the liquid fuel is usually first fed to a porous fuel treatment element which serves to store, disperse and vaporize the fuel. In particular, e.g. Also, a plurality of porous fuel treatment elements may be provided which are each adapted to these different functions.

WO 2012/155897 A1 describes an evaporator arrangement for an evaporator burner for a mobile heater, in which an evaporator body has at least one layer of a metal fabric of interwoven metal wires. It is further described to provide a multi-layered structure using e.g. a layer of a metal fabric is combined with another layer of a metal fleece.

It is an object of the present invention to provide an improved porous fuel treatment element, an improved evaporator burner and an improved heater.

The object is achieved by a porous fuel treatment element according to claim 1. Advantageous developments are specified in the dependent claims. The porous fuel processing element for an evaporator burner has at least one layer formed of fibers. The fibers have basalt fibers. The fibers of the at least one layer may in particular be formed by basalt fibers, for example. However, it is also possible, for example, that in addition to basalt fibers also other fibers are present. In this example, the entire fuel treatment element may be formed of basalt fibers or at least be formed of one or more layers having basalt fibers. However, it is also possible, for example, for the porous fuel conditioning element additionally to have one or more layers which contain no basalt fibers. Basalt fibers in this application have distinct advantages over conventional fibrous materials used for porous fuel treatment elements. As compared to, for example, glass fibers or asbestos fibers, basalt fibers have superior physical, mechanical and chemical properties with respect to use in a porous fuel processing element. Basalt fibers are a very strong, yet flexible fiber material, which is particularly easy to form into textile fabrics, in particular a felt, a fleece, a needle mat, a scrim, a woven fabric, a knitted fabric, a knitted fabric or a braid can process. The material is particularly suitable for evaporator burners, which are designed for very high operating temperatures, since basalt fibers have an extremely high temperature resistance, especially in comparison to conventional materials, in particular metal fleeces and metal fabrics. Furthermore, a very low tendency for deposit formation is achieved and it can still provide a high storage or buffering effect

unvaporized, liquid fuel can be provided. Furthermore, it is a very inexpensive and harmless material.

According to a development, the at least one layer comprises a textile fabric, in particular a felt, a fleece, a needle mat, a scrim, a woven fabric, a knitted fabric, a knitted fabric or a braid. In this case, the properties of the fuel processing element can be specified in a very targeted manner by the selection of the textile fabric. Furthermore, it is also possible, for example, to combine different types of textile fabrics together, for example one or more layers of nonwoven with one or more layers of fabric, etc. According to a development, the fibers of the textile fabric have a diameter distribution in the range between 5 μιη and 35 μιη. In this case, a very well-defined distribution of the diameter of the fibers is given, so that the properties of the fuel processing element can be adjusted specifically. Furthermore, it is reliably ensured with such a well-defined diameter distribution that no health risks are associated with the handling of the fibers.

In particular, if the fibers have a length of at least 150 μιη, preferably a length of at least 200 μιη, health hazards in handling can be excluded particularly reliable. The basalt fibers can be present in the porous fuel preparation selement particularly preferably as so-called endless fibers with a very large length, which can be produced technically in a known manner.

According to a development, the porous fuel treatment element may have at least one layer of basalt wool. In particular, the aforesaid at least one layer may comprise basalt wool or it may be e.g. but also be provided in addition one or more other layers that have basalt wool or are formed from basalt wool. The use of basalt wool allows a particularly cost-effective production. According to a development, the porous fuel treatment element has at least one further layer formed from fibers. The fibers of the at least one further layer may preferably also comprise basalt fibers. In this case, a particularly advantageous, in particular temperature-resistant, design is given. Alternatively, it is e.g. however, it is also possible for the at least one further layer to comprise other fibers, e.g. in particular metal fibers or metal wires.

According to a development, the fibers of the at least one layer have a glassy, amorphous structure. According to a development, the fibers of the at least one layer are sintered together. In this case, a particularly robust and dimensionally stable realization of the fuel treatment element is possible, which in turn allows easy handling during assembly of the evaporator burner. Furthermore, in this case can be dispensed with an additional separate support structure, which would cause further costs and labor. According to a development, the fibers are formed by fiber bundles, multifilaments and / or rovings.

The object is also achieved by an evaporator burner for a mobile fuel heater operated with liquid fuel with such a porous fuel treatment element.

Furthermore, the object is also achieved by a heater with an evaporator burner, which has such a porous fuel processing element.

Further advantages and developments will become apparent from the following description of an embodiment with reference to the accompanying drawings.

FIG. 1 is a schematic illustration of a portion of an evaporator combustor having a porous fuel treatment element in a mobile fuel-fired heater according to an embodiment; FIG.

Fig. 2 a) is a schematic representation of an evaporator receptacle with a

Fuel processing element according to a first modification of the embodiment;

Fig. 2 b) is a schematic representation of an evaporator receptacle with a

Fuel processing element according to a second modification of the embodiment;

Fig. 3 a) is a schematic representation of an evaporator receptacle with a

A fuel processing element according to a third modification of the embodiment;

Fig. 3 b) is a schematic representation of an evaporator receptacle with a

A fuel processing element according to a fourth modification of the embodiment;

Fig. 3 c) is a schematic representation of an evaporator receptacle with a

A fuel processing element according to a fifth modification of the embodiment;

4 is a view of a fuel processing element according to a first embodiment

Execution sf orm, Fig. 5 is a view of a fuel processing element according to a second

Execution sf orm,

Fig. 6 a) - g) are schematic representations of various textile fabrics, as which the fuel processing element can be realized. Fig. 7 is a schematic exploded view for explaining the arrangement of the fuel processing element in an evaporator receptacle.

Fig. 8 is a schematic exploded view for explaining the arrangement of the fuel processing element in the evaporator receptacle in a

Modification.

EMBODIMENTS

A first embodiment will be described in more detail below with reference to FIG. 1.

FIG. 1 schematically shows a region of an evaporator receptacle 2 and a burner cap 3 of an evaporator burner 1 for a mobile heating appliance. Fig. 1 is a schematic representation in a plane containing a main axis Z of the evaporator burner. The evaporator burner can, for example, essentially have a rotational symmetry with respect to the main axis Z. The evaporator burner 1 may be formed, for example, for a vehicle heater, in particular an auxiliary heater or a heater. The evaporator burner 1 is designed in particular to implement in a combustion chamber 4, a mixture of vaporized fuel and combustion air, so a fuel-air mixture, releasing heat. The reaction can be carried out in particular in a flaming combustion, but a partial or fully catalytic conversion is also possible. The released heat is in a (not shown) heat exchanger on a medium to be heated, which may be formed, for example, by air or a cooling liquid transferred. In particular, the heat exchanger, the discharge for the hot combustion gases, the likewise provided combustion air delivery device (eg a fan), the fuel delivery device (eg a metering pump), the control unit for controlling the evaporator burner, etc. are not shown in the schematic representation of FIG. These components are well known and well described in the art. The evaporator burner 1 has an evaporator receptacle 2, in which a porous fuel treatment element 5 is arranged. The evaporator receptacle 2 has in the embodiment on a substantially cup-shaped shape. The fuel conditioning element 5 is received in the pot-like depression of the evaporator receptacle 2 and in particular can be held firmly in this, for example by welding, soldering, jamming or with the aid of a suitable securing element. The design of the fuel processing element 5 will be described in more detail below.

A fuel supply line 6 for supplying liquid fuel to the fuel preparation element 5 is provided. The fuel supply line 6 opens into the evaporator receptacle 2 and communicates with a (not shown) fuel delivery device, via which liquid fuel can be conveyed through the fuel supply line 6 to a predetermined extent, as shown schematically by an arrow F. The fuel supply line 6 is, e.g. by welding or soldering, firmly connected to the evaporator receptacle 2.

The combustion chamber 4 is circumferentially bounded by a combustion chamber 7, e.g. may be formed by a substantially cylindrical member made of a temperature-resistant steel. The combustion chamber 7 is provided with a plurality of holes 7a, via which combustion air can be fed into the combustion chamber 4, as shown schematically in FIG. 1 by arrows.

The holes 7a are part of a combustion air supply L, is supplied via the combustion air to a side facing away from the fuel supply line 6 side of the fuel processing element 5. The evaporator burner 1 is designed such that liquid fuel can be supplied to the fuel processing element 5 via the fuel supply line 6 during operation. In and on the fuel processing element 5 on the one hand by a plurality of cavities, a distribution of the fuel over the entire width of the fuel processing element 5 and on the other hand on the combustion chamber 4 side facing evaporation or evaporation of the fuel. In the illustrated embodiment, the Brennstoffaufbereitung selement 5 has a substantially circular cross-sectional shape, in the center of which the main axis Z of the evaporator burner 1 extends. However, the fuel processing element 5 may also have other cross-sectional shapes. The evaporator burner 1 is designed such that in the fuel processing element 5 and at its surface evaporation or evaporation of the liquid fuel takes place and the vaporized fuel only at the exit from the fuel processing element 5, ie combustion chamber side, with the supplied combustion air to a fuel-air - Mixture is mixed. The supply of liquid fuel and combustion air thus takes place on different sides of the fuel processing element 5. The implementation of the fuel-air mixture in an exothermic reaction does not take place in the fuel treatment element 5, but in the downstream combustion chamber 4. Thus, liquid fuel and fuel vapor are present in the fuel processing element 5 during operation of the evaporator burner 1 and, due to the evaporation or evaporation process, any initially existing air is expelled from the fuel processing element 5.

In the exemplary embodiment schematically illustrated in FIG. 1, the fuel conditioning element 5 has a construction with a plurality of functional regions, which in the example shown concretely comprises a first region B1 and a second region B2 having one of the structure in the first region B. 1 divergent structure is divided. The second region B2 is arranged in the embodiment of the fuel supply line 6 facing and the first region B 1 is arranged facing the combustion chamber 4.

In the first modification of the embodiment shown schematically in FIG. 2a), the fuel conditioning element 5 does not have a plurality of different functional regions, but only a first region B1 is given. In the second modification of the embodiment shown schematically in FIG. 2 b), the fuel conditioning element 5 has a stepped design with a total of three regions B 1, B 2, B 3 and the evaporator receptacle 2 is designed accordingly. In such a case, for example, the different areas B 1, B 2, B 3 can be designed specifically with regard to different functions of the fuel conditioning element 5. For example, the second region B2 may be optimized for fuel delivery via capillary forces and fuel buffering, the third region B3 may be optimized for lateral distribution of fuel and serve as tolerance compensation, and the first region B1 may be fuel vaporized Be optimized or fuel evaporation. The different areas B 1, B 2, B 3 can in this case in particular they differ from each other in their structure, structure, material and / or thickness, etc.

Further possible embodiments of fuel treatment elements 5 with a plurality of functional areas B 1, B 2, B 3 are shown schematically in FIGS. 3 a, 3 b and 3 c. Although in FIGS. 3a, 3b and 3c, the fuel supply line 6 and other components are not shown again, it is understood that these other components are also present in these other modifications.

In the following, the structure of the fuel processing element 5, as it can be used in the embodiment and the modifications described above, will be described in more detail. The embodiment described below can be used for each of the individual areas B 1, B 2 and B 3, in particular e.g. even in cases where only one such area exists.

4 shows a layer 8 formed of fibers 10 of a porous fuel treatment element 5 according to a first embodiment. The layer 8 is formed in the embodiment of a fabric whose fibers have 10 basalt fibers. In the specific embodiment shown, the fabric is formed in particular from basalt fibers which are woven together. In the event that the porous fuel treatment element 5 has one or more further layers 9, these may also be formed, for example, from such a fabric. The fibers 10 within the layer 8 formed may also be fiber bundles, multifilaments or rovings. 5 shows a layer 8 formed of fibers 10 of a porous fuel treatment element 5 according to a second embodiment. The sheet 8 is formed in the second embodiment as a nonwoven fabric having basalt fibers. In the specific embodiment shown, the nonwoven is formed in particular from basalt fibers. In the event that the porous fuel treatment element 5 has one or more further layers 9, these may also be formed, for example, from such a nonwoven. Furthermore, it is also possible, for example, to combine one or more layers of such a nonwoven with one or more layers of a previously described fabric in a fuel treatment element 5. Furthermore, one or more layers may also be formed as a textile fabric in a porous fuel treatment element 5, as will generally be described below with reference to FIGS. 6 a) to 6 g). It should be noted that, in particular, any desired combinations of such textile fabrics can be used in a porous fuel treatment element.

Various realizations of the at least one layer 8 (or possibly also the further layer 9) of the porous fuel treatment element 5 are shown in FIGS. 6 a) to g). The various implementations have the common feature that the fibers 10 each have base fibers. In particular, the fibers 10 may each be formed by basalt fibers.

Fig. 6a) is a schematic representation of a web as a textile fabric for the layer 8 or 9, as has also been described with reference to FIG. 5.

Fig. 6b) is a schematic representation of an alternative in which the textile fabric for the layer 8 or 9 is formed by a felt.

FIG. 6c) is a schematic representation of a textile fabric formed as a fabric of basalt fibers for the layer 8 or 9, as was also described with reference to FIG. 4.

Fig. 6d) shows schematically a formation of the layer 8 or 9 as a knit. Fig. 6e) shows schematically a formation of the layer 8 or 9 as a braid. Fig. 6f) shows schematically a formation of the layer 8 or 9 as a knitted fabric. Fig. 6g) shows schematically a formation of the layer 8 or 9 as a scrim.

It should be noted that the various fabrics described with reference to FIGS. 6 a) to 6 g) can be combined with one another in almost any desired manner in a porous fuel treatment element 5. In the textile fabrics described above, it is particularly advantageous if the fibers 10, ie the basalt fibers in the specific embodiment, have a very narrow diameter distribution with diameters in the range between 5 μιη and 35 μιη and the fibers 10 each have a length greater than 150 μηι , Favor greater than 200 μιη have. Particularly preferably, the fibers 10 in this case, for example, be designed as so-called continuous fibers. The fibers 10 have an amorphous, glassy structure. For example, the surface of the fibers 10 may be treated with a size during manufacture to achieve improved machinability.

As an alternative to the textile fabrics described above or additionally thereto, the layer 8 or 9 may also comprise basalt wool, which enables a particularly cost-effective production. The integration of the previously described fuel conditioning element 5 with at least one layer 8 or 9, which comprises basalt fibers, into an evaporator assembly of an evaporator burner 1 will be briefly described below with reference to the schematic exploded view in FIG. As shown schematically in FIG. 7, the previously described fuel treatment element 5 is inserted into the pot-like depression of the evaporator receptacle 2. In order to ensure a sufficient mechanical stability in the long term even at high temperatures, a support structure 11 is applied to the combustion chamber side of the fuel treatment element 5, which is e.g. In particular, may be formed by a temperature-resistant metal mesh or metal fabric. There is a fastening of the fuel processing element 5 and the support structure 11 in the evaporator receptacle 2 via a retaining ring 12. The retaining ring 12 may be formed in particular in a conventional manner as a snap ring, which is jammed or caulked to the evaporator receptacle 2, or it can eg a connection of the retaining ring 12 with the evaporator receptacle 2 by welding or soldering done. The evaporator assembly formed in this way can then be integrated into the evaporator burner 1 in a simple manner.

MODIFICATION

In a modification of the previously described embodiment, the mechanical stability of the porous treatment element 5 is increased by bonding the fibers 10 together by sintering. In this method, at the crossing points of the fibers 10 forms a firm connection between them. The sintering can eg by a purely thermal process, in which the formation of the compound takes place only by providing an elevated temperature and, if appropriate, additional compression of the fibers 10. As an alternative to such a purely thermal process, however, it is also possible, for example, to support the sintering process by chemical processes by applying additional binders / sintering aids to the fibers.

As shown schematically in FIG. 8, this modification achieves an increased mechanical stability of the fuel conditioning element 5, so that the additional support structure 11 can be dispensed with in the construction of the evaporator assembly.

Claims

claims

Porous fuel conditioning element (5) for an evaporator burner (1), comprising:

at least one layer (8) formed from fibers (10),

wherein the fibers (10) comprise basalt fibers.

A porous fuel processing element according to claim 1, wherein said at least one layer (8) comprises a fabric.

The porous fuel processing element of claim 2, wherein the fabric is a felt, a nonwoven, a needle mat, a scrim, a woven fabric, a knit, a knit or a braid.

Porous fuel conditioning element according to one of the preceding claims, wherein the fibers (10) of the textile fabric have a diameter distribution in the range between 5 μιη and 35 μιη.

Porous fuel processing element according to one of the preceding claims, wherein the fibers (10) have a length of at least 150 μιη, preferably a length of at least 200 μιη.

Porous fuel treatment element according to one of the preceding claims, wherein the porous fuel treatment element (5) has at least one layer (8, 9) of basalt wool.

Porous fuel conditioning element according to one of the preceding claims, with at least one further layer (9) formed from fibers (10).

Porous fuel processing element according to claim 7, wherein also the fibers (10) of the at least one further layer (9) comprise basalt fibers.

A porous fuel processing element according to any one of the preceding claims, wherein the fibers (10) have a glassy, amorphous structure.

Porous fuel processing element according to one of the preceding claims, wherein the fibers (10) of the at least one layer (8) are sintered together.

11. Porous fuel processing element according to one of the preceding claims, wherein the fibers (10) are formed by fiber bundles, multifilaments and / or rovings.

Evaporator burner (1) for a mobile fuel heater operated with a liquid fuel with a porous fuel treatment element (5) according to one of the preceding claims.

13. A heater with an evaporator burner (1) having a porous fuel processing element (5) according to any one of claims 1 to 11.