Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D11/00—Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space
  • F23D11/10—Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space the spraying being induced by a gaseous medium, e.g. water vapour
  • F23D11/106—Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space the spraying being induced by a gaseous medium, e.g. water vapour medium and fuel meeting at the burner outlet
  • F23D11/107—Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space the spraying being induced by a gaseous medium, e.g. water vapour medium and fuel meeting at the burner outlet at least one of both being subjected to a swirling motion
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D2212/00—Burner material specifications
  • F23D2212/10—Burner material specifications ceramic

Definitions

• the invention relates to a nozzle for atomizing liquid fuel by means of air flowing through the nozzle with an air inlet area, an air outlet area and a flow path connecting the air inlet area with the air outlet area.
• Generic nozzles are used, for example, in vehicle heaters.
• Vehicle heaters of this type can be operated, for example, as additional heaters and / or as auxiliary heaters.
• the nozzle is used to supply combustion air, liquid fuel, for example diesel or gasoline, being carried along and atomized from a fuel needle due to the flow of the combustion air.
• combustion air liquid fuel
• fuel needle due to the flow of the combustion air.
• a mixture of combustion air and fuel is obtained, which, if appropriate after being mixed with air supplied on other flow paths, can be burned, as a result of which the heat required for heating operation is generated.
• This heat generated by a burner then heats a heat transfer medium, for example water or air.
• Prior art nozzles are often made of metal, with castings or turned parts being used.
• a disadvantage of such components is the comparatively high production outlay and the generally high thermal conductivity of the metals. Thermal conductivity can cause problems if the temperature in the area of the fuel needle rises excessively due to the heat generated in the burner.
• To solve the problems, which are connected to the metallic nozzles have already been proposed in a previous patent application to use a ceramic nozzle.
• the flow behavior of the combustion air is important for the mixing of the combustion air with the fuel in the common way of these substances through the nozzle.
• it has already been proposed in DE 100 39 152 A1 to impart a swirl to the combustion air.
• a carrier with swirl vanes was connected upstream of the inlet area of the nozzle.
• a disadvantage of such a carrier with upstream swirl blades is, however, that an additional component is required, on the basis of which the tolerances existing for an undisturbed function of the nozzle can sometimes be exceeded.
• the invention has for its object to provide a nozzle which is inexpensive to produce, has a low thermal conductivity compared to metal and brings about advantageous properties with regard to the flow behavior of the combustion air, adjustment problems being avoided.
• the invention builds on the generic nozzle in that the nozzle consists of ceramic material, in the air inlet area means for air guidance are provided which impart a swirl to the inflowing air, and in that the means for air guidance are formed in one piece with the nozzle.
• the ceramic material can be processed in a simple manner, with numerous variations in terms of shape being possible.
• the means for guiding the air which cause a swirl to the combustion air outside the air inlet area, can be formed in one piece with the nozzle.
• the invention is advantageously developed in that the nozzle has means for holding a glow plug.
• the positioning of the glow plug in relation to the nozzle is an important parameter with regard to good starting behavior of the burner.
• the glow plug was generally held by the burner housing, so that positioning fluctuations with respect to the nozzle could result.
• Such tolerances can be excluded by the property of the nozzle according to the invention that the nozzle itself has means for holding the glow plug.
• the glow plug is always in the same position with respect to the nozzle.
• the nozzle according to the invention is further developed in an advantageous manner in that the nozzle has at least partially an essentially cylindrical shape and in that the means for guiding air form channels which are offset with respect to the radial directions.
• the air flowing in perpendicular to the axis of the nozzle is therefore not supplied radially but with an offset. This offset determines the swirl that is supplied to the combustion air so that the Flow behavior and ultimately also the properties and quality of the combustion.
• the air guiding means have essentially triangular bases, the corners being rounded. This allows the channel offset to be implemented in a simple manner. The rounding of the corners is advantageous for a uniform flow behavior.
• the air guiding means can also be designed as blades. Such blades can also provide the offset channels, so that the combustion quality is also positively influenced by this.
• the means for holding the glow plug are implemented as a bore running obliquely to the cylinder axis.
• the glow plug then only has to be inserted into the hole for suitable positioning.
• a stop on the glow plug and / or within the bore ensures that the glow plug is guided into its optimal position with respect to the nozzle.
• the nozzle according to the invention is developed in a particularly advantageous manner in that an at least substantially cylindrical part of the nozzle has a substantially cylindrical extension with an enlarged diameter and that the means for holding the glow plug are implemented as a bore which runs obliquely to the cylinder axis and penetrates the extension.
• the glow plug can be kept in an area in which it influences the flow behavior of the inflowing fuel / air mixture as little as possible. Due to the cylindrical approach, which has a larger diameter than the rest of the nozzle body, this can be accomplished in a simple manner.
• an at least substantially cylindrical part of the nozzle has an essentially cylindrical extension with an enlarged diameter and that the cylindrical extension has recesses for receiving mounting bolts.
• These mounting bolts Zen can, for example, be firmly attached to a heat shield of the burner.
• the relative positioning of the nozzle is determined in this way by the recesses in the neck and the position of the mounting bolts. This makes assembly particularly easy and possible with only small tolerances.
• the nozzle is a venturi nozzle.
• the Venturi effect for atomizing the fuel emerging from the fuel needle can be advantageously combined in this way with the swirl supplied to the combustion air. The effects support each other and thus lead to high quality combustion.
• the invention is based on the knowledge that an inexpensive to produce nozzle with a shape that can be varied within wide limits is made available by using a ceramic material.
• the shape of the nozzle can be expanded so that means for air flow that an incoming
• Combustion air impart a swirl can be formed in one piece with the nozzle.
• the ceramic also has the advantage that an undesirably high temperature in the area of the fuel needle can be avoided.
• Another task is to create a heater for mobile applications that is inexpensive to manufacture.
• Figure 1 is a partially sectioned schematic representation of a heater in which the present invention can be used;
• Figure 2 is a partially sectioned side view of an embodiment of a nozzle according to the invention;
• FIG. 3 shows a plan view of the air inlet area of a nozzle according to the invention;
• FIG. 4 shows a nozzle according to the invention mounted on a burner.
• FIG 1 shows a partially sectioned schematic representation of a heater in which the present invention can be used.
• a heater 10 is shown with a burner 12 for burning a fuel / air mixture.
• the heating device comprises an annular duct blower 14 with a blower motor 36.
• the annular duct blower 14 draws combustion air 42 through an air inlet connection 16 and blows it into a combustion air plenum 18 on the pressure side.
• the combustion air available in the combustion air plenum 18 is divided into primary air and secondary air.
• the primary air is conveyed into the combustion chamber 24 through a nozzle 20, which in the present example is designed as a Venturi nozzle.
• the secondary air is conveyed through secondary air bores 22 into the combustion chamber 24.
• the division of the combustion air into primary air and secondary air is useful in order to provide a rich, ignitable mixture at the outlet of the nozzle 20.
• the nozzle 20 includes a settling zone 26 and a diffuser 30 to provide the venturi effect.
• a fuel needle 28 is arranged within the nozzle 20.
• the fuel needle 28 is supplied with fuel 44 via a fuel line 82. Due to the high flow rate of the
• the flow rate of the fuel / air mixture is drastically reduced in the course of the diffuser 30, as a result of which low flow rates are achieved in the area of a glow plug 62 indicated in FIG. 2. the.
• a baffle plate 32 is arranged within the combustion chamber 24. This represents an obstacle to flow, so that the air emerging from the nozzle 20 is forced outwards. This results in a good mixing of the primary air with the secondary air, which is useful in terms of good burnout.
• the region between the nozzle 20 and the baffle plate 32 thus serves as a mixing zone 34, and the region beyond the baffle plate 32, that is to say the region lying downstream with respect to the baffle plate 32, serves as the reaction zone 38.
• the mixture produced burns in the further course of the combustion tube 40 and becomes passed through the exhaust gas-carrying parts from the heater 10.
• the incoming heat heats up cold water 46 in the heat exchange with the exhaust gas-carrying parts, so that warm water 48 emerges from the heater 10.
• Air for example, can also be used as the heat transfer medium.
• FIG. 2 shows a partially sectioned side view of an embodiment of a nozzle 20.
• a nozzle 20 can be used, for example, in a heater 10 as shown in FIG. 1.
• the nozzle 20 is made of ceramic material, which simplifies the manufacture of the nozzle 20 compared to metal nozzles.
• the nozzle 20 has an air inlet area 50 and an air outlet area 52.
• the air inlet area 50 is connected to the air outlet area 52 via a flow path 54.
• this flow path 54 is subdivided into a calming zone 26 and a diffuser 30.
• Means 56 for air guidance are provided in the air inlet area. These air guide elements 56 are formed in one piece with the ceramic nozzle 20.
• the air guide elements 56 are aligned in such a way that a swirl is imparted to the supplied air, which is explained in more detail below with reference to FIG. 3.
• a fuel needle 28 (see FIG. 4) can be arranged in the calming region 26, so that a mixture of fuel and air emerges from the nozzle 20. This can then be done via a glow plug 62, which can be inserted into a bore 58 of the nozzle 20, is ignited.
• the positioning of the glow plug 62 is thus fixed with respect to the nozzle 20, since the glow plug 62 is held by a bore 58 of the nozzle 20, that is to say in particular not by any other components. Very small tolerances with regard to the installation position of the glow plug 62 can thus be maintained.
• the bore 58 advantageously passes through a cylindrical shoulder 64 of the nozzle 20 which is enlarged in its radius, which has the advantage that the flow behavior of the nozzle 20 is only slightly influenced by the bore 58 or by the glow plug 62 arranged in the bore 58 ,
• FIG. 3 shows a top view of the air inlet area 50 of a nozzle.
• a possible configuration of the air inlet area 50 by air guiding elements 56 is shown.
• the air guide elements 56 form channels 60 for the inflowing air. These channels 60 are positioned with respect to the radii of the structure essentially arranged on an axis such that there is an offset. Air flowing in from outside thus experiences a swirl, which has advantageous properties with regard to the atomization of the fuel which emerges from the fuel needle to be arranged in the calming region 26.
• the arrangement of the opening 58 for receiving the glow plug can be seen in the present illustration. This penetrates an essentially cylindrical projection 64.
• the projection 64 is further provided with recesses 66. These recesses 66 define the installation position of the nozzle 20, which is explained in more detail below with reference to FIG. 4.
• FIG. 4 shows a partially sectioned view of a device according to the invention.
• An end of the burner 12 facing the nozzle 20 is shown.
• the burner 12 is delimited by a heat shield 78.
• two mounting bolts 68 are provided on this heat shield 78. These mounting bolts 68 can be welded to the heat shield 78 or to the burner 12.
• the mounting bolts 68 define the positioning of the further components described below.
• a seal 76 is provided, which is preferably made of a mica layer and a graphite layer, the mica layer facing the burner 12 and the graphite layer facing the nozzle 20.
• the ceramic nozzle 20 which with its recesses 66 shown in FIG. 3 sits non-rotatably on the mounting bolt 68.
• a fuel supply 70 which is connected to the fuel needle 28, is placed on the nozzle 20.
• This fuel supply 70 is also positioned by means of holes 84 provided in a side flange through the mounting bolts 68.
• the fuel supply 70 is supplied with fuel by a fuel line 82, in which a fuel sensor 80 is arranged.
• the fuel supply 70 is followed by a spring 72, which is also placed on the mounting bolt 68.
• the spring 72 is held by clamping disks 74 which sit immovably on the mounting bolts 68.
• the spring 72 is shown in a tensioned state in which the legs of the spring 72 are, for example, parallel to the disc in between. In the relaxed state of the spring 72, the legs of the spring 72 are bent upwards in the direction of the disc in between.
• the glow plug not shown in FIG. 4, is positioned by the nozzle 20 in accordance with the embodiment of FIG. 2 and held by a wire spring (not shown) which is supported on the nozzle 20.
• the fuel supply 70 and thus the fuel needle 28 are automatically aligned with respect to the nozzle 20.
• Glow plug 62 can also be positioned exactly with respect to nozzle 20 and burner 12.
• the construction of the structure shown in FIG. 4 can be fully automated.
• the mounting direction is uniformly axial, so that only the components 76, 20, 70, 72 and 74 have to be “threaded on”.
• the seal 76 provides thermal insulation, a coupling of the nozzle ceramic 20 to the metal of the heat shield 78 and a tolerance compensation.
• the structure can be mounted in an advantageous manner by force-controlled pressing of the clamping disks 74 onto the mounting bolts 68, so that with regard to the heat and temperature properties uniform conditions can be created.
• force-controlled pressing of the clamping disks 74 onto the mounting bolts 68 so that with regard to the heat and temperature properties uniform conditions can be created.
• the spring force of the spring 72 By means of the spring force of the spring 72, tolerances due to different heating of the components, different final temperatures of the components and different temperature expansion coefficients can be compensated for.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Nozzles For Spraying Of Liquid Fuel (AREA)
• Spray-Type Burners (AREA)

Priority Applications (7)

Applications Claiming Priority (1)

Publications (1)

Family

ID=32913724

Family Applications (1)

Country Status (7)

Cited By (2)

Families Citing this family (3)

Citations (5)

Family Cites Families (20)

• 2003
  • 2003-02-28 US US10/546,956 patent/US20060214030A1/en not_active Abandoned
  • 2003-02-28 AU AU2003233909A patent/AU2003233909A1/en not_active Abandoned
  • 2003-02-28 DE DE10394238T patent/DE10394238D2/de not_active Expired - Fee Related
  • 2003-02-28 WO PCT/DE2003/000666 patent/WO2004076922A1/de active Application Filing
  • 2003-02-28 EP EP03727133A patent/EP1597515A1/de not_active Withdrawn
  • 2003-02-28 CN CNA038260638A patent/CN1748108A/zh active Pending
  • 2003-02-28 JP JP2004568629A patent/JP2006514254A/ja active Pending

Patent Citations (5)

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