Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
  • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
  • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
  • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
  • F01N3/023—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles
  • F01N3/025—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles using fuel burner or by adding fuel to exhaust
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D3/00—Burners using capillary action
  • F23D3/40—Burners using capillary action the capillary action taking place in one or more rigid porous bodies
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23D—BURNERS
  • F23D2207/00—Ignition devices associated with burner

Definitions

• the invention relates to an evaporator burner with a combustion chamber for a heater or a thermal regeneration of an exhaust gas particle filter, with a circumferential boundary wall, which has a lateral outer connection piece for accommodating an ignition device, a forehead limiter tongue wall, which has a central opening, an air supply pipe protruding coaxially into the combustion chamber, which has radial air outlets through the pipe wall, and with a fuel supply.
• Hitherto known evaporator burners have combustion chambers which operate on the principle that the fuel is applied to a wall or introduced into a porous material and is evaporated and burned from there. Evaporation, reaction and combustion take place in one, so they are not separated.
• the combustion air is either fed directly to the combustion chamber and distributed throughout the combustion chamber, or radially via bores (via the outer jacket) or via a central air tube which is provided with bores and which has a flame tube at a certain distance from the tube outlet.
• Common to these combustion chambers is that they have a relatively low power density, i.e. have a relatively low output based on the combustion chamber volume.
• the object of the invention is to provide an evaporator burner of the type mentioned at the outset, which can be used in many fields, enables efficient combustion of a different type from the aforementioned prior art, and in particular has a simple and compact design and is efficiently manufactured and can be assembled.
• the object on which the invention is based is achieved by an evaporator burner in accordance with the features of patent claim 1.
• a guiding device to the air supply connection of the combustion chamber, which ensures that the combustion air is supplied in a swirling flow to the (cylindrical) air supply connection during operation of the burner.
• the swirl flow is a three-dimensional flow, the main component of which runs tangentially in the area of the air supply nozzle near the wall, the radial component of the flow being relatively weak and the axial component of the flow being relatively strong.
• the radial air outlets through the nozzle wall ensure that the high tangential speed component is deflected and accelerated, the "swirl" being essentially destroyed or a positive or negative residual swirl being established.
• the radial air outlets can be open-ended longitudinal slots or closed through-windows in the nozzle wall and on the circumference of the nozzle wall, optionally arranged in an inclined position and / or formed with angled edges in order to set up the aforementioned (positive or negative) residual swirl.
• the guide device for the swirl flow is set up in the form of guide vanes, which can be formed, in particular, integrally or in one piece with the air supply connector, with connectors and guide vanes being, for example, a single casting.
• the combustion chamber is followed by a coaxial flame tube, which stabilizes the flame during operation and serves to guide the exhaust gas (hot gas).
• a particularly cost-effective production and assembly of the burner results if the flame tube and the peripheral boundary wall or the combustion chamber jacket are formed in one piece, in particular as a sheet metal (deep-drawn) part, while in particular the rest of the combustion chamber parts are preferably cast parts only casting, are.
• Sheet metal (deep-drawn) parts and castings can be welded together or for "thermal decoupling" via an insulating element, e.g. a flat gasket, be firmly connected.
• an insulating element e.g. a flat gasket
• the fuel is supplied to the combustion chamber annulus on the one hand via an annular channel in frontal arrangement to the combustion chamber jacket or alternatively via the lateral outer connector in which the ignition device, e.g. a glow plug or glow plug is arranged in different positions (obliquely, axially, radially, tangentially with respect to the combustion chamber axis).
• the ignition device e.g. a glow plug or glow plug is arranged in different positions (obliquely, axially, radially, tangentially with respect to the combustion chamber axis).
• a porous lining for evaporating supplied fuel can be provided on the inside of the combustion chamber shell or on the peripheral boundary wall of the combustion chamber.
• the air supply nozzle can be closed at its downstream end or, in an advantageous further development, can be open and provided with a cover.
• the central through opening of the end panel partially flows back the exhaust gas or the air in the area of the burner axis or in the vortex center of the swirl flow air supplied and is again fed to the combustion chamber annulus through the radial air passages in the nozzle wall.
• This recirculated exhaust gas or air stream takes part in the combustion at least one more time (recirculation), a low-pollution combustion with low pollutant emissions being set up.
• the diameter of the through opening or the diaphragm diameter is determined by experiment.
• the invention enables the construction of a burner which is very simple in construction, easy to manufacture and assemble and is highly efficient to operate.
• the burner is particularly suitable for additional heaters, such as auxiliary heaters, auxiliary heaters, stoves, camping stoves, but also for so-called soot burners, for automotive catalytic converter preheating, for a refrigerator, a field kitchen, home heating or simply for firing systems.
• the burner is preferably a so-called blue burner with exhaust gas recirculation, which results in low-pollutant combustion.
• the burner is suitable for petroleum.
• the component load is low since the diffusion flame takes place in the annular combustion chamber between the air supply connection and the peripheral wall of the combustion chamber. Since the flame pattern is homogeneous, the burner can also be operated with high efficiency in heat exchangers.
• a coaxial flame holder or a coaxial flame shield can also be provided after the end cover of the air supply connector, then such devices can be dispensed with for certain requirements and arrangements.
• the ambient air can optionally be drawn in automatically during operation, the end orifice also being used as a flow cone or the like. can be trained (e.g. with a stove).
• a homogeneous flame pattern in the annular space between the circumferential boundary wall and the air supply nozzle is expediently supported by the fact that the liquid fuel is supplied on the end face over the entire circumference of the porous lining, ie fuel supplied in the porous lining over the entire circumference of the jacket inwards into the annular space (gasification zone) can evaporate.
• the ring channel for the fuel is preferably provided on the end face of the porous lining, which is created by a distributor ring which is round or angular in cross section and has bevels and which is located in an associated inner wall pocket in the region of the end faces ⁇ tion wall of the combustion chamber is located.
• the ring channel has a preferably axial connection for a fuel supply line, which is angled radially outward outside the connection area to the ring channel, ie can extend parallel to the end wall of the combustion chamber.
• the distribution ring can have circumferentially, in particular, equally distributed axial through-bores, the number of axial through-bores preferably being equal to the number of radial air outlets, which are preferably equally distributed over the circumference of the air supply connector.
• a transition ring can be arranged between the end face of the porous lining, web, sintered metal or the like, and the aforementioned ring channel in order to compensate for manufacturing tolerances, e.g. a triton ring which is particularly absorbent and adaptable.
• the combustion air is therefore swirled via a guide device and fed to a central air distribution pipe which projects into the combustion chamber.
• This tube is provided with radial slits or openings as well as a cover which can be opened or closed.
• the combustion air enters the annular combustion chamber radially through the slots.
• the three-dimensionally supplied combustion air has a high tangential speed component, which is strongly redirected and accelerated at the radial slots (that is, the slot tube destroys the swirl, it works as a swirl destroyer).
• the air roller is peeled and straightened, so to speak.
• the accelerated air jets emerging from the slots form highly turbulent zones (vortices) in their edge region, which extend as far as the combustion chamber wall.
• the highly turbulent zones form to the right and left of the slots, that is, in the area of the webs.
• the annulus height, slot width, number of slots and slot length are determined.
• a positive or negative residual swirl is maintained in the combustion chamber. This can be achieved by slits made at an angle (at a certain angle). The slots then cause a stronger or weaker deflection of the tangential speed component.
• the end panel in the central air distribution pipe has the task of diverting the swirled combustion air through the slots.
• a partial exhaust gas flow can be returned via this orifice (orifice diameter is determined in the experiment), which again participates in the combustion (recirculation).
• the three-dimensional swirl flow in the center expediently has a flow cone with a negative axial velocity component in the area of the orifice in the central air distributor pipe.
• the high swirl required for this can be generated with a corresponding guide device (blade angle, blade height, number of blades), but this means a higher energy expenditure on the part of the fan (e.g. an electrical power consumption in a household burner).
• combustion chamber with low energy consumption (power consumption of the blower as low as possible) (e.g. vehicle parking heater, stove) (e.g. vehicle parking heater, stove)
• power consumption of the blower as low as possible
• the combustion air is also deflected via the slots, as before, but there is no longer any hot gas recirculation.
• the ignition device In or on the gasification room or smoker room, the ignition device attached or introduced.
• the ignition device In the ideal case, the ignition device generates an independent pilot flame which initiates the evaporation process in the pre-evaporation zone.
• the pilot flame continues to burn automatically after switching off the ignition aid (glow plug, glow plug).
• the fuel can be fed directly into the combustion chamber or via the ignition device.
• the ignition device preferably has an ignition air supply.
• the air duct components are preferably made of investment casting, this including the guide device, the air distributor pipe and, if necessary, a fastening flange.
• combustion chamber jacket and the hot gas guide tube (flame tube) from investment casting, the combustion chamber jacket then providing the air guide parts is assigned.
• this embodiment has the disadvantage that relatively high masses have to be heated up and it is important for certain burner requirements to be able to drive high power as quickly as possible (auxiliary heater), it is expedient to remove the combustion chamber jacket and the hot gas guide tube from the separate air-conducting parts and execute them in thin-walled sheet metal.
• This preferably one-piece part has the advantage of low mass and thus heats up very quickly, which is advantageous for the gasification and evaporation process.
• a further advantage is that the air guiding part is a smaller component than a complete combustion chamber, and thus more parts are produced from one casting, which lowers the unit price.
• the aforementioned component can be used for thermal decoupling (Note: Air guiding parts cool or transfer heat to the electric motor) in such a way that an insulator in the form of a seal is inserted between the combustion chamber jacket and the air guiding part.
• the burner according to the invention differs from the known burners mentioned at the outset in the type of air distribution and supply for combustion and in the type of mixture preparation as well as in its high power density, which means that higher outputs are achieved from comparable combustion chamber volumes.
• FIG. 2 shows another evaporator burner similar to FIG. 1,
• FIGS. 1 and 2 show a third embodiment variant of an evaporator burner in a longitudinal section similar to FIGS. 1 and 2,
• FIG. 5 shows the detail A of FIG. 4,
• FIG. 6 shows the detail of FIG. 5 at another circumferential location
• FIG. 7 shows the detail of FIG. 6 in another embodiment
• FIG. 8 shows the embodiment variant according to FIG. 7 with a transition ring in the direction of the porous lining
• 9 is a schematic partial section of the downstream end of an air duct with an end panel
• Fig. 10 shows the cross section B-B through the air guide socket according to Fig. 9, and
• FIG. 11 shows a cross section through an evaporator burner, showing a lateral ignition device.
• the evaporator burner illustrated in FIG. 1 comprises a cylindrical combustion chamber 1 and a coaxial flame tube 20 in a connection open on the top side according to FIG. 1.
• the combustion chamber 1 comprises a flat stim boundary wall 6, an essentially cylindrical circumferential boundary wall 2 which projects upwards at right angles from the end boundary wall 6, and a cylindrical air supply pipe which projects centrally upward at right angles from the end boundary wall 6 socket 8 coaxial to the circumferential boundary wall 2 and a porous cylindrical lining 3 arranged on the inner circumference of the circumferential boundary wall 2, an integrated outer lateral connection 4 for accommodating an ignition device 5, for example a glow plug, being formed in the circumferential boundary wall 2 is.
• the fuel supply to the combustion chamber 1 also takes place via the side connection 4, as described below in conjunction with FIG. 11.
• the porous lining 3 has at least one radial through opening or an ignition hole 24 in order to ignite or transfer a flame from the connection piece 4 into the annular space between the peripheral boundary wall 2 or the porous lining 3 and the air supply connection piece 8 to which an integrated guide device 32 with guide vanes 31 according to FIG. 2 is assigned, which is in particular cast on.
• the air supply pipe 8 is formed in one piece with the end boundary wall 6 as an investment casting and on its upper, i.e. s closed downstream end of the rome, but provided in this end area with radial air outlets 9 in the nozzle wall, which are evenly distributed on the circumference of the nozzle and are described in more detail below.
• a flame shield 19 or a flame holder with a central opening is arranged coaxially downstream of the air supply connection 8 and is attached to the inner circumference of the cylindrical circumferential boundary wall 2 via a cylindrical outer flange.
• Flame tube 20 and circumferential boundary wall 2 acc. Fig. L are integrally formed from sheet metal in the form of a deep-drawn part and welded by means of a circumferential weld 25 to the aforementioned casting consisting of the end boundary wall 6 and the air supply connector 8.
• the casting is comparatively small.
• a comparatively large number of castings can be cast in a single casting box, which reduces manufacturing costs.
• the air supply nozzle 8 is accessible all around (Entfor he).
• the combustion chamber jacket or the circumferential boundary wall 2 with integrated flame tube 20 made of sheet metal requires comparatively little material and makes a significant contribution to reducing the mass of the burner.
• the combustion chamber 1 can also be operated without a liner 3, contrary to the embodiment variant according to FIG. 1, since the fuel supply and fuel vaporization take place via the lateral connection piece 4 of the ignition device 5 (cf. FIG. 11).
• the air supply connection 8 has, in a coaxial arrangement (according to FIG. 1, below), the guide device 32 (not illustrated) according to FIG. 2, which supplies air to the connection 8 in a swirl flow, the swirl flow primarily on the The inner circumference of the air supply nozzle 8 is formed and the air with the force component directed radially outwards is accelerated through the radial air passages 9 into the combustion chamber annulus or the annulus is "loaded" with air.
• FIG. 2 of an evaporator burner with a diffusion flame or a gasification burner essentially corresponds to that according to FIG. 1, but here the deep-drawn sheet metal part consisting of flame tube 20 and circumferential boundary wall 2 and the cast part consisting of end wall 6 and the air supply connector 8 and the guide device 32 with guide vanes 31 are not connected by means of a weld seam 25, but rather are provided at this circumferential location with an intermediate insulating element 21, the sheet metal part and the cast part being connected to one another in a sealed manner by means of (not shown) fastening means. Sheet metal and casting are therefore thermally decoupled. A direct connection to the hot parts is interrupted.
• FIG. 3 basically corresponds in structure to that according to FIGS. 1 and 2, but no flame shield 19 is provided here. Furthermore, the circumferential boundary wall 2 is here in one piece with the end boundary wall 6 and the air supply connector 8 as an investment casting, while the flame tube 20 is a sheet metal part.
• the air supply pipe 8 has at its upper end a cover 10 in the form of a plug, which can also be a plate or a flow cone.
• the closure panel 10 has a central through-opening 11 which runs exactly coaxially with the overall arrangement and forms an axial backflow R for burned combustion air or exhaust gas, as will be described below.
• the evaporator burner according to FIG. 3 has a fuel supply 7 with a fuel supply line 13, as is the case, for example, in the embodiment variant of an evaporator burner according to FIG 4, which uses an annular channel 12.
• the combustion chamber 1 is an evaporator combustion chamber, which is preferably produced from a cast cylindrical combustion chamber housing with a bottom, the combustion chamber housing on the jacket in the axial direction being a pocket for the ignition device, e.g. has a glow plug or a glow plug, and the ignition device can protrude obliquely into the combustion chamber annulus. Further possible arrangements of the ignition device are described in connection with FIG. 11.
• the air supply socket 8 In the center of the combustion chamber pot there is the air supply socket 8 or the longitudinal slot configuration, which uniformly distributes the air L supplied from below in a radial direction towards the inner chamber of the combustion chamber, the swirl flow preferably in an upstream vortex. chamber or a control device is generated.
• the radial air outlets 9 through the wall of the air supply connector 8 can also have oblique slots and other geometric openings or the like with additional deflection edges. 9, 10, which have angled edges with respect to the radial extension of the air supply connector 8.
• the axially supplied combustion air is therefore a swirl flow L, which has its maximum speed in the area near the stud wall and, because of the open shut-off orifice 10 in the center, forms a backflow cone in the area of the shut-off orifice 10, which in the case of combustion results in a partial reverse flow R causes.
• the partial return flow again passes through the radial air outlets 9 in the nozzle wall into the annular combustion chamber (“recirculation”) and takes part again in the combustion, which results in a particularly low-emission combustion.
• the partial return flow can be an exhaust gas recirculation in a closed burner system or in an open system of an atmospheric burner the intake of ambient air, which then leads to a blue burner.
• the cover can be a plate, a flow cone or the like. and preferably has a cylindrical central through opening 11, which can also be frustoconical and conically widened in the direction of the end boundary wall 6.
• the capillaries are represented as follows:
• the fuel supply 7 takes place via the ring channel 12 according to FIGS. 5 to 8, which is formed on the combustion chamber floor near the inner wall.
• This ring channel 12 is formed in particular in the area of the end boundary wall 6 by a wall pocket 15 on the inside of the combustion chamber, in which a coaxial distributor ring 14 is received.
• the distributor ring can have a round cross section according to FIGS. 5 and 6 or a rectangular cross section according to FIG. 7.
• Axial through-bores 17, which are distributed identically or unevenly around the circumference, can extend through the distributor ring 14 in order to also sufficiently supply the downstream side of the ring channel with fuel.
• the porous cladding 3, web or the like as shown in FIGS. 5 and 6, or a transition ring 18, preferably made of Triton or the like, which in turn adjoins the end face of the porous lining 3 and compensates for tolerances in the manufacture of the individual parts.
• the fuel supply thus takes place via an annular space with the formation of an annular channel 12 which can be rectangular or trapezoidal in particular and / or can be provided with roundings.
• the fuel is fed into this channel through the combustion chamber floor via the fuel supply line 13 at a certain angle, preferably in the axial direction of the combustion chamber.
• the ring channel is essentially closed in the direction of the porous lining in order to ensure that the incoming fuel is distributed circumferentially to the left and right, with two ring capillaries being formed on the circumference of the combustion chamber base be filled with fuel very quickly and distribute it in the circumferential direction.
• the ignition device 5 for example a glow plug, is heated in the side nozzle 4, a partial air flow being sent via the side nozzle 4, which then forms an ignitable mixture in connection with the fuel evaporated at the porous lining 3 there .
• the small pilot flame heats the combustion chamber annulus and then ignites the evaporating fuel.
• the combustion air emerging from the slots or windows of the air supply connector 8 forms a turbulent zone in the radial direction in the region near the wall, with right and left rotating vortex zones.
• a guide device provided, for example, with 12 longitudinal slots, 12 left and 12 right-turning vortices are then formed, for example.
• the fuel evaporated by the heat of combustion is detected by these vortex zones and blue-burned in a diffusion flame.
• the flame fills the entire combustion chamber annulus.
• a higher number of slots is preferably used, since this increases the turbulent zone.
• the combustion takes place for the most part in the combustion chamber annulus between the cross-sectional slot base and slot height and between the slots, that is to say in the area of the webs. The combustion in the combustion chamber area is thus completed.
• the flame tube 20 serves only to guide the hot gas and to homogenize the temperature distribution in the tube, with no more fuel in this tube burns.
• FIG. 11 illustrates, in particular in the case of a combustion chamber 1 with a porous lining 3, a lateral outer connector 4 for a tangentially arranged ignition device 5, for example a glow plug.
• the ignition device can also be located axially or radially inwards with respect to the burner axis.
• Both the ignition air 26 and the fuel 27 are supplied via ring channels around the ignition device 5, which is surrounded by a porous casing 30 or a sieve, web or the like.
• the fuel is ignited in the side nozzle 4, the flame being generated being transmitted through the ignition hole 24 in the porous lining 3 into the combustion chamber annulus. Since the porous jacket 30 closely adjoins the porous lining 3 of the combustion chamber 1, the fuel supplied to the jacket 30 is also transferred to the porous lining 3 and evaporated on the inside of the combustion chamber jacket and ignited by the flame passing through the ignition hole 24.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Wick-Type Burners And Burners With Porous Materials (AREA)
• Spray-Type Burners (AREA)

Priority Applications (2)

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Publications (1)

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Family Applications (1)

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Cited By (7)

Families Citing this family (9)

Citations (4)

• 1995
  • 1995-11-03 CZ CZ19971428A patent/CZ290040B6/cs not_active IP Right Cessation
  • 1995-11-03 WO PCT/DE1995/001546 patent/WO1996015408A1/de active IP Right Grant
  • 1995-11-03 JP JP8515633A patent/JP2848965B2/ja not_active Expired - Lifetime

Patent Citations (4)

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