Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23M—CASINGS, LININGS, WALLS OR DOORS SPECIALLY ADAPTED FOR COMBUSTION CHAMBERS, e.g. FIREBRIDGES; DEVICES FOR DEFLECTING AIR, FLAMES OR COMBUSTION PRODUCTS IN COMBUSTION CHAMBERS; SAFETY ARRANGEMENTS SPECIALLY ADAPTED FOR COMBUSTION APPARATUS; DETAILS OF COMBUSTION CHAMBERS, NOT OTHERWISE PROVIDED FOR
  • F23M9/00—Baffles or deflectors for air or combustion products; Flame shields
• • 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
  • F23M—CASINGS, LININGS, WALLS OR DOORS SPECIALLY ADAPTED FOR COMBUSTION CHAMBERS, e.g. FIREBRIDGES; DEVICES FOR DEFLECTING AIR, FLAMES OR COMBUSTION PRODUCTS IN COMBUSTION CHAMBERS; SAFETY ARRANGEMENTS SPECIALLY ADAPTED FOR COMBUSTION APPARATUS; DETAILS OF COMBUSTION CHAMBERS, NOT OTHERWISE PROVIDED FOR
  • F23M5/00—Casings; Linings; Walls
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49348—Burner, torch or metallurgical lance making

Definitions

• the invention relates to the combustion chamber of a burner for a vehicle heater or for thermal regeneration of an exhaust gas.
• Particulate filter which has an end wall, a peripheral wall, a nozzle for accommodating a glow plug and a nozzle for supplying combustion air, which projects from the end wall into the fuel chamber and has at least combustion air outlets through the nozzle wall.
• the object of the invention is to make a combustion chamber which can be produced more efficiently available.
• Glow plug connector and with or without the air supply connector designed as a one-piece investment casting component.
• the invention makes it possible to drive the investment casting integral design of the combustion chamber very far or less. Including the air supply nozzle in the integral construction results in a particularly high rationalization effect. But even an investment casting component, into which the air supply connection piece, which in turn is either made from bent sheet metal or by the investment casting process, is subsequently inserted, already offers advantages over the conventional design. From the further description it will be clear that in a further development of the invention further functional components of the combustion chamber can also be included in the investment casting integral construction.
• a typical representative of investment casting technology preferred in the invention is the lost wax process known per se.
• Wax model which has the shape of the investment casting component that is ultimately to be produced.
• a larger number of these wax models is then, connected to a common pouring channel, molded into a molding material, which often consists of ceramic particles with a binder.
• the wax models melt and the resulting mold cavities are filled with liquid metal.
• the molding material is destroyed to demould the investment cast components.
• scaling-resistant and heat-resistant steel alloys are preferred, in particular steel alloys from the group of stainless steel.
• the glow plug socket is preferably aligned at least substantially parallel to the longitudinal direction of the combustion chamber and is designed as a bulge in the circumferential boundary wall.
• the bulge can have a part-circular shape, in particular an essentially semicircular shape or a shape lying between semicircular and three-quarter circle.
• the glow plug socket In the longitudinal direction, the glow plug socket is usually shorter than the circumferential boundary wall.
• the air supply nozzle can be open at its downstream end to the inside of the briner chamber (which creates an end
• Combustion air outlet results) or be closed at this end (so that it only has the combustion air outlet through the nozzle wall).
• a flame holder downstream of said open end which distributes the combustion air flow emerging from the open end towards the circumferential boundary wall, so that it supplies the oxygen for the complete combustion of the fuel.
• the flame holder is preferably a plate which is convexly curved toward the air supply nozzle.
• the flame holder can be a separate, retrofitted component, but can also be part of the investment casting component mentioned earlier.
• the combustion chamber have a mounting flange for mounting it in the overall burner, the mounting flange in most cases transverse to
• the longitudinal direction of the combustion chamber extends.
• the investment casting component mentioned preferably has the fastening flange in one piece. From a manufacturing point of view, it is most favorable if the fastening flange lies at least substantially in a continuation of the end boundary wall radially-externally. So far, the air supply nozzle has been made entirely tubular with distributed perforations in the nozzle wall.
• the air supply nozzle has longitudinal slots in the nozzle wall as combustion air outlets. Part of the longitudinal slots or all of the longitudinal slots extend to the downstream end of the air supply nozzle.
• the longitudinal slots in investment casting technology are much easier to produce than bore-like openings in the nozzle wall. However, the provision of longitudinal slots does not preclude the presence of bore-like combustion air outlets in the nozzle wall.
• the described configuration of the air supply nozzle with longitudinal slots represents a preferred development of the previously described first aspect of the invention (“combustion chamber in investment casting technology”), in particular because an air supply connector with longitudinal slots is easy to manufacture in investment casting technology that, on the other hand, the described second aspect of the invention represents an independent invention, which can also be technically advantageously implemented separately from the idea of investment casting technology.
• a longitudinal slot, several longitudinal slots or all longitudinal slots - measured in the circumferential direction of the air supply nozzle - can have a constant width across the slot longitudinal direction.
• Combustion air is available. This is an example of that Situation that the downstream end of the air supply nozzle can be formed closed, because sufficiently large air outlet cross-sections are available in the downstream end region of the air supply nozzle through the nozzle wall.
• At least one of the combustion air outlets through the connecting piece wall is designed such that the combustion air with flow component flows out in the circumferential direction of the air supply connecting piece. This achieves an outlet for the combustion air, not essentially in the radial direction, but with a more or less pronounced flow component in the circumferential direction, so that there is a swirl flow in the combustion chamber, which is favorable for the combustion of the fuel in the combustion chamber.
• the air supply nozzle with an inner cross section that tapers in the direction of flow.
• the combustion chamber according to the invention is preferably designed as an evaporative combustion chamber.
• a porous lining for evaporating the fuel can be provided on the inside of the end boundary wall and / or the peripheral boundary wall.
• the lining does not have to completely cover the end boundary wall and / or the peripheral boundary wall.
• Porous lining can, but need not, also be provided inside the glow plug socket.
• Conventional materials for the porous lining are non-woven fabrics, in particular made of ceramic fibers, or fiber metal materials. It is understood that the porous lining is supplied with fuel from the outside, which evaporates from the lining into the combustion chamber.
• a combustion chamber is provided, the lining of which is made of sintered metal.
• This third aspect of the invention represents, on the one hand, a preferred embodiment of the invention described above, but, on the other hand, it also represents an independent invention, which is detached from the characterizing one
• a porous lining made of sintered metal is considerably more durable than a ceramic bevel, can be produced with very uniform porosity and high accuracy of fit. and provides an optimal wall contact u of the concerned
• Combustion chamber wall It is also possible to use the same or a similar material for the lining as the remaining functional components of the beehive chamber so that recycling of the combustor is made easier. Finally, the thickness of the lining can be changed from place to place as required
• the sintered metal lining can be produced in situ in the combustion chamber by the material of the lining, ie the Particles, introduced in the unsintered state into the combustion chamber and vei sintered there in place noisymalei w iid wiid a Kei n inserted into the combustion chamber for this purpose, so that a gap-shaped shaping space between the St ⁇ n boundary wall or the circumferential boundary wall and the kernel arises into which the particles to be sintered are filled.
• the vin sintering takes place in the usual way by supplying heat. The sintering in situ provides optimal contact between the lining and the relevant boundary wall of the combustion chamber
• N ' is ah to a fourth aspect of the invention betw een the circumferential
• Boundary wall and the air supply nozzle a guide and support ring ⁇ on the front boundary wall from a piece arranged so that it projects towards the interior of the combustion chamber
• the leeward and protective ring causes a more axial flow of those emerging in the upstream end area from the air supply nozzle
• this fourth aspect of the invention on the one hand represents a preferred embodiment of one or more of the inventive aspects described above, but on the other hand represents an independent invention, detached from the investment casting component idea specified in the characterizing part of claim 1, because the design according to the fourth aspect of the invention can also be used technically advantageously independently of this.
• the guide and protection ring does not necessarily have to extend over 360 °. In the case of lower requirements, it may be sufficient if it extends as a partial ring over a partial circumference of the combustion chamber, in particular where fuel is most likely to drop onto the air supply nozzle.
• the downstream end region of the guide and protective ring is preferably designed such that it acts to increase the turbulence on the combustion air flow, that is to say it promotes the mixing of evaporated fuel and combustion air there.
• the combustion chamber according to the invention can essentially have a cylindrical configuration in end view, but it does not have to be so.
• the end of the lining which is closer to the end boundary wall of the combustion chamber and / or the end of the lining which is further away from the end boundary wall of the combustion chamber is fixed in an annular gap which is continuous or interrupted in sections.
• the lining can be extremely technical simply attach in the combustion chamber.
• Sections of interrupted fixing ring or a component can be provided which is attached to a flame tube continuing the combustion chamber.
• Invention on the one hand represents a preferred embodiment of one or more of the aspects of the invention described above, but on the other hand represents an independent invention, detached from the investment casting component idea specified in the characterizing part of claim 1, because the design according to the fifth aspect of the invention can also be implemented technically advantageously independently of this.
• the fixing ring for the end of the lining which is closer to the end boundary wall is preferably part of the investment casting component.
• Fixing the position of the lining can be perfected by bending the fixing ring at least at its free end after inserting the lining onto the lining, which results in the lining being clamped in place.
• the insertion of the end of the lining in the annular space is particularly simple if - seen in longitudinal section - this space tapers towards its end and / or the lining has a tapering end. It is particularly preferred when fastening the lining according to the fifth aspect of the invention that the lining is only on the circumferential
• the peripheral boundary wall of the combustion chamber has an inside
• the liner can only be introduced into the combustion chamber in a certain position (with respect to rotation about the longitudinal axis of the combustion chamber), so that e.g. an opening in the lining, which is to be positioned opposite the nozzle for the glow plug, automatically comes to the right place.
• this sixth aspect of the invention on the one hand represents a preferred embodiment of one or more of the above-described aspects of the invention, but on the other hand represents an independent invention, detached from the investment casting component idea specified in the characterizing part of claim 1, because the design according to the sixth aspect the invention can also be implemented technically advantageously independently of this.
• a device for generating flow swirl is provided in the flow path of the combustion air in front of the air supply nozzle.
• the swirling combustion air flow leads to a more optimal formation of a combustible fuel-air mixture.
• this seventh aspect of the invention on the one hand represents a preferred embodiment of one or more of the above-described aspects of the invention, but on the other hand represents an independent invention, detached from that stated in the characterizing part of claim 1
• Investment casting component ideas because the training according to the seventh aspect of the invention can also be implemented technically advantageously independently of this.
• the device for generating flow swirl is at least largely part of the investment casting component or at least largely part of the housing of a combustion air blower placed in front of the combustion chamber.
• the device can have, in particular, a diffuser, a flow space delimited spirally on the circumference or the like.
• a fuel distribution channel is provided at the transition between the circumferential boundary wall of the combustion chamber and the lining, which extends at least over part of the circumference of the circumferential boundary wall.
• the fuel distribution channel ensures that the fuel supplied is already distributed over the rear of the lining over a larger area. The result is a more uniform evaporation of the fuel over a larger area of the lining and a reduction in the risk of fuel dripping from the lining.
• this eighth aspect of the invention on the one hand represents a preferred embodiment of one or more of the above-described aspects of the invention, but on the other hand represents an independent invention, detached from the investment casting component idea specified in the characterizing part of claim 1, because the design according to the eighth aspect the invention can also be implemented technically advantageously independently of this.
• a fuel supply nozzle for fuel supply opening into the fuel distribution channel is provided essentially in the circumferential direction.
• a fuel feed connection further promotes the achievement of the advantages discussed above.
• a heat conducting finger is provided radially further outward than the circumferential boundary wall of the combustion chamber, the end of which is located further forward than its root in the longitudinal direction of the combustion chamber, and is on the outside of the combustion chamber component in the area where the
• a temperature sensor is attached, with which it can be determined whether combustion takes place in the burner chamber or not.
• Exhaust gas particle filters have so far generally been equipped with a so-called flame detection or flame termination detection. If it is determined with the aid of this device that no combustion process or combustion process takes place unintentionally in the combustion chamber, at least the
• the mounting location of the temperature sensor is shifted to the combustion chamber component; the result is a significantly simplified production and problems of the type described are avoided.
• the heat-conducting finger is preferably a component of the fine component.
• the ninth aspect of the invention on the one hand represents a preferred embodiment of one or more of the above-described aspects of the invention, but on the other hand represents an independent invention, detached from what is stated in the characterizing part of claim 1
• Investment casting component ideas because the training according to the ninth aspect of the invention can also be implemented technically advantageously independently of this.
• At least a part of the surfaces that tend to build up carbon-containing deposits in operation is copper-containing.
• the surfaces that are suitable for copper-containing training the following are mentioned in particular: inside of the lining for evaporating the fuel, outside of the air supply nozzle, inside of the
• Nozzle for the glow plug boundary walls of the combustion chamber (in particular if or where there is no lining), the flame tube downstream of the combustion chamber, surface of the heat exchanger on the combustion gas side.
• this tenth aspect of the invention on the one hand represents a preferred embodiment of one or more of the above-described aspects of the invention, but on the other hand represents an independent invention, detached from the investment casting concept specified in the characterizing part of claim 1, because the design according to the tenth aspect the invention can also be implemented technically advantageously independently of this.
• copper-containing alloys or provide a coating with copper-containing material.
• fibers made of copper-containing material can be added to the lining material.
• particles of copper-containing material can be added to the particles to be sintered.
• the term "copper-containing material" used above also includes pure copper and copper alloys.
• the combustion chamber according to the invention is preferably part of a burner for a vehicle heater or part of a burner for the thermal regeneration of an exhaust gas particle filter.
• Vehicle heaters are used in particular for passenger cars, the cabins of trucks, buses, sailing and motor boats, construction machinery,
• the vehicle has an internal combustion engine as the drive.
• the vehicle heater can be integrated into the coolant circuit and the regular heating circuit of the internal combustion engine, so that the vehicle heater can be used as an additional heater if it is insufficient
• Heat supply of the internal combustion engine and / or as auxiliary heating can be used when the internal combustion engine is at a standstill.
• Ab ⁇ as particle filters are increasingly being installed in the exhaust system of stationary or diesel engines used for vehicle propulsion.
• the particle filter often simply called “soot filter”, retains the particles contained in the exhaust gas from diesel engines.
• the particle filters have to be freed of the filtered particles, usually at intervals, which can be done in particular by thermal regeneration. For thermal regeneration, the gas flow to the particle filter is heated so strongly that the ignition temperature of the particles of about 650 to 700 ° C. is reached and the particles are burned with oxygen contained in the supplied gas stream.
• FIG. 1 shows a combustion chamber in longitudinal section.
• FIGs 8 to 12 various versions of a guide
• 13 shows a combustion chamber of another embodiment in longitudinal section, two different variants being drawn at the top and bottom; 14 is a cross section along A-A of the combustion chamber of FIG
• Fig. 13 shows a modification of the combustion chamber of Fig. 13 in a longitudinal section showing part of the combustion chamber; 16 shows another modification of the combustion chamber of FIG.
• Fig. 17 shows a vehicle heater with a combustion chamber component of another embodiment in longitudinal section.
• the combustion chamber 2 shown in Fig. 1 consists essentially of a flat end boundary wall 4, which merges radially on the outside into a mounting flange 6, a cylindrical peripheral boundary wall 8, which extends from the end boundary wall 4 at right angles, one centrally from the end boundary wall 4 at right angles to the right, cylindrical air supply Connector 10 and a glow plug connector 12.
• the mounting flange 6 has a circular outer circumference.
• the air supply nozzle 10 is concentric with the circumferential boundary wall 8, but smaller in diameter than the circumferential boundary wall 8, so that between the air supply nozzle 10 and the circumferential
• Boundary wall 8 an annular space is formed.
• the longitudinal central axis of the combustion chamber 2 is designated 14. Measured in the axial direction, the air supply connection piece 10 is approximately half as long as the circumferential boundary wall 8
• the glow plug socket 12 When viewed in cross section, the glow plug socket 12 has a part-circular inner contour that extends over approximately 240 °.
• the partial circumferential wall of the glow plug socket 12 represents, as it were, a bulge in the circumferential boundary wall 8, the circumferential boundary wall 8 being interrupted where the glow plug socket 12 connects.
• the glow plug socket 12 does not extend to the right up to the end of the circumferential boundary wall 8.
• the longitudinal central axis 16 of the glow plug socket 12 lies somewhat outside the circumferential boundary wall 8 and is parallel to the axis 14.
• the wall of the air supply socket 10 points circumferentially distributed and in two
• All previously mentioned parts of the combustion chamber 2 are formed together as an integral investment casting component.
• the air supply nozzle 10 can alternatively also be manufactured separately and then combined with the investment casting component.
• An essentially cylindrical air supply housing 19 is attached to the left of the end boundary wall 4 and may, but does not have to, contain a guide device for generating a swirl flow entering the air supply connection piece 10.
• a fan is connected to the air supply housing 19 and supplies the combustion air with the required excess pressure.
• a plate 22 which is convexly curved towards the left, is arranged as a flame holder, which is pulled against the webs 20 by means of a central-axially extending, small rod 24.
• the small rod 24 passes through the end end wall of the air supply housing 19 and is fastened there by a screwed nut 26.
• the curved plate is made of sheet metal. But it could also be integrated with the webs 20 in the investment casting component; in this case the small rod 24 would be unnecessary.
• 1 also shows a porous lining 28 on the inside on the end boundary wall 4 and on the inside on the circumferential boundary wall
• the porous lining 28 is preferably made of sintered metal and has preferably been sintered in situ there. In the axial direction, the lining 28 is somewhat shorter than the circumferential boundary wall 8 in the embodiment shown, but could also be the same length or even longer than the circumferential boundary wall 8. In that one
• the liner 28 has an opening 30, the size of which is only a fraction of the size of the interruption of the peripheral
• Has boundary wall 8 can also have practically the entire size of the interruption.
• the area of a glow plug that glows when the current passes through, whether it be a glow plug with a filament or a glow plug, is accommodated in the glow plug socket 12.
• a guide and protective ring 32 can be seen in FIG. 1, which projects at right angles from the end boundary wall 4 to the right into the annular space between the circumferential boundary wall 8 and the air supply connector 10.
• the axial length of the ring 32 is 5 to 30%, preferably 8 to 20%, of the axial length of the
• the ring 32 is preferably integral with the investment casting.
• FIG. 1 At the top left in FIG. 1 there is also a bore 34 which is inclined at 45 ° for the supply of fuel, it being possible for an unillustrated nozzle with a press fit to be inserted into the bore 34. In reality, the bore 34 is rotated by 150 ° with respect to the position shown next to the glow plug socket 12.
• the combustion chamber 2 has an overhead glow plug socket
• combustion chamber 2 works as follows:
• Fuel ie generally diesel fuel or gasoline, is fed to the lining 28 via a metering pump and through the bore 34.
• the glow plug (not shown) is supplied with current, whereupon it begins to glow in its front area. Supported by the heating by means of the glow plug, fuel evaporates from the lining 28 towards the interior of the combustion chamber 2, but also into the interior of the glow plug socket 12. The ignition of the fuel-air mixture then takes place on the glow plug, and the resulting flame propagates through the opening 30 into the annular space between the circumferential boundary wall 8 and the air supply socket 10.
• combustion air flows out of the air supply housing 20 through the air supply nozzle 10 and from there through the radial holes 18 into the described annular space, where the initial combustion of the fuel-air mixture takes place.
• the main part of the combustion air flows further downstream through the large gaps between the webs 20 to the outside into the combustion chamber of the combustion chamber 2.
• the guide and protective ring 32 creates a low-flow ring pocket radially outside of this, in which a rich fuel-air mixture can form. Fuel dripping downward from the liner 28 reaches the ring 32 instead of the air supply sockets 10 and is torn away downstream by the combustion air from the right downstream edge in FIG. 1.
• the glow plug socket 12 can also have a small opening (not shown) for supplying a small amount of purge air.
• Fig. 2 a construction of the air supply nozzle 10 is illustrated, in which instead of the round holes 18 there are longitudinal slots 40, which start a little behind the upstream end of the nozzle 10 and up to the downstream end of the
• a flat or curved plate can be placed directly on the downstream end of the nozzle 10, corresponding to the plate 22 of FIG. 1. Alternatively, in the axial direction
• Extension of the connector 10 webs 20 as in the embodiment of Figure 1 can be cast. the plate, not shown, would then rest against the free ends of these webs 20.
• FIG 3 shows a variant in which the longitudinal slots - measured in the circumferential direction of the connecting piece 10 - have a width 42 that increases progressively in the flow direction.
• the nozzle 10 tapers conically in the direction of flow.
• Stubs 10 runs arched inwards.
• embodiments of the connector 10 are drawn in cross section, in which the longitudinal slots 40 and connector wall regions 44 alternate with one another.
• the longitudinal slots 40 are shaped so that they have a combustion air outlet
• Air supply sockets 10 and the glow plug socket 12 are formed as a one-piece investment casting component.
• FIGS. 8 to 12 Various variants of the design of the guide and protective ring 32 are illustrated in FIGS. 8 to 12. In the embodiments according to
• Combustion air is given turbulence or its turbulence is increased.
• 11 shows a design of the downstream end of the ring 32 as a sharply tapering, outwardly bent spraying edge.
• Fig. 12 shows an embodiment of the ring with inclined grooves or projections on the inside to the air flowing past there
• Corresponding grooves or protrusions could be provided on the outside of the ring 32 for guiding spilled fuel in the spiral direction.
• the ring 32 need not be cylindrical, but could also be conical, tapering or widening in the downstream direction.
• the combustion chamber 2 shown in FIGS. 13 and 14 has, as far as analogous to the combustion chamber 2 in FIG. 1, a flat end face.
• Boundary wall 4 a cylindrical circumferential boundary wall 8, a cylindrical air supply nozzle 10, a glow plug socket 12, and a fastening flange 6, which, however, goes further to the right of the circumferential boundary wall 8 to the radially outward than in the embodiment from FIG 1.
• the air supply nozzle is the same as for the
• Embodiment of FIG. 2 executed with longitudinal slots 40. All Parts of the combustion chamber 2 mentioned so far are formed together as an integral investment casting component. However, it is pointed out that the air supply nozzle 10 can alternatively also be manufactured separately and then combined with the investment casting component.
• the combustion chamber 2 of FIGS. 13 and 14 has a guide apparatus for generating flow swirl in the combustion air flowing to the air supply nozzle 10, the curved guide vanes 50 of which are cast integrally with the investment casting component of the combustion chamber.
• the guide vanes 50 occupy slightly less than the space of the end boundary wall 4 in the radial direction and project directly from this axially to the left in FIG. 13.
• the guide vanes 50 are through a circular, continuous one
• the plate 52 covered, so that the combustion air must flow exclusively from the radially outside into the flow channels between the guide vanes 50 and enters the air supply sockets 10 with very considerable swirl about the longitudinal central axis 14 of the combustion chamber 2.
• the plate 52 can also be cast integrally with the investment casting component, but can alternatively also be a separately manufactured, subsequently attached and fastened part.
• the device for generating flow swirl can preferably be placed in front of the air supply nozzle 10
• Flow space can be formed with a spiral-like peripheral wall.
• the combustion air can be fed tangentially to this flow space on the circumferential wall that runs with a smaller radius of curvature.
• the flow space described can be in a correspondingly thick housing wall of a combustion air blower placed in front of the combustion chamber 32, see e.g. Housing wall 80 in
• Fig. 13 also shows a novel attachment of the porous lining 28 in the combustion chamber 2.
• Lining 28 purely cylindrical and thus not cup-shaped as in Embodiment of Fig. 1 is; the lining 28 is thus provided on the inside of the circumferential boundary wall 8, but not on the inside on the end boundary wall 4.
• a fixing ring 54 projects from the end boundary wall 4 toward the interior of the combustion chamber 2, specifically with a radial distance to the inside of the circumferential
• Boundary wall 8 which corresponds essentially to the radial thickness of the lining 28.
• the left end of the liner 28 in FIG. 13 is inserted into the annular gap 56 thus formed between the circumferential boundary wall 8 and the fixing ring 54, the fixing ring 54 being slightly bevelled on the outside on the right to facilitate insertion.
• FIG. 1 With regard to the fastening of the right end of the lining 28 in FIG. 13, two different variants are drawn in FIG. 1 above the longitudinal central axis 14 and below the longitudinal central axis 14.
• a flame tube 58 made of sheet metal is attached to the investment casting component of the combustion chamber 2, which is shown in broken lines in FIG. 13, but in reality is considerably longer in the axial direction than the combustion chamber 2.
• a piece away from its left end is fixed in the flame tube 58 a flame shield 60, which is made of sheet metal and has a large central flow opening 62, which constricts the gas flow compared to the inner diameter of the circumferential boundary wall 8 or the flame tube 58 locally.
• the flame shield 60 is bent at the transition for fastening in the flame tube 58 in such a way that an annular gap 64 remains between the flame tube 58 and an area 66 of the flame shield which runs essentially parallel to the flame tube 58.
• the right end of the lining 28 in FIG. 13 is pushed into this annular gap 64, so that the described region 66 of the flame shield 60 acts as a fixing ring for the lining 28.
• the liner 28 is relatively long in the axial direction, that is, it leads a little way out of the circumferential boundary wall 8 into the flame tube 58.
• the lining 28 ends on the right before the end of the circumferential boundary wall 8 is reached.
• a ring-like component 68 is attached to it, which projects to the left and is bent inwards at the left end so that an annular gap 64 is there
• the flame tube component 58 is pushed to the left onto the combustion chamber component 2 and is fastened there by welding, the right end of the lining 28 is also received in the relevant annular gap 64, as described.
• the lining 28 is fixed on the inner circumference of the circumferential boundary wall 8 because of the two-sided locking.
• the radial dimensions of the annular gaps 56 and 64 can, but need not, be such that the ends of the
• Lining 28 are included with some pinching; to facilitate assembly, the ends of the liner 28 can be formed with a chamfer on the inside. It is also pointed out that the lining 28 does not necessarily have to be fixed at both ends. In particular in the case of a relatively stiff consistency and / or a design of the lining 28 that is not too long in the axial direction, the fixing at only one axial end can be sufficient. In this case, however, a real position fixation should be preferred, e.g. by clamping.
• the webs 20 are widened radially inwards at their free end, so that the plate 22 can be easily welded there.
• Fig. 14 it can be seen that the lining 28 is cylindrical overall, but at one point on its circumference has a continuous slot in the axial direction and in the radial direction.
• a projection 70 extending in the axial longitudinal direction of the combustion chamber 2 is provided on the inside of the circumferential boundary wall 8.
• the projection 70 ensures that the liner 28 is about the angular position Longitudinal central axis 14 is aligned in a specific position and that the lining 28 is fixed with regard to circumferential displacements.
• the aforementioned alignment ensures that the opening 30 of the liner 28 is in the correct position relative to the socket 12 for the glow plug.
• the slot in the lining 28 does not have to go completely through in the radial direction, but, for example, only one axially running channel can be provided in the outside of the lining. Furthermore, it is alternatively possible to provide the lining with an axially extending projection on the outside and accordingly to provide an axially extending groove on the inside of the peripheral boundary wall 8.
• FIGS. 13 and 14 it can also be seen that on the inside of the circumferential boundary wall 8 there is a circumferential direction
• Fuel distribution channel 72 is present, which by a flat-groove-like
• Indentation is formed in the material of the combustion chamber component.
• the distribution channel 72 runs in a circle practically over the entire circumference.
• the fuel system 74 has an orientation essentially in the circumferential direction of the circumferential boundary wall 8.
• Fuel is fed in such a direction that it continues to flow smoothly in the distribution channel 72 and, distributed over a larger area, enters the lining 28 from behind.
• the socket 12 for the glow plug has such an orientation that its longitudinal central axis 16 lies essentially or exactly in a plane that extends at right angles to the longitudinal central axis 14 of the combustion chamber 2 (drawing plane of FIG. 14).
• Fig. 15 shows a modification in which the fixing ring 54 is formed in its right, free end region with a relatively small wall thickness and after inserting the end of the liner 28 has been bent radially outwards to clamp the liner
• the annular gap 56 can easily be slightly larger in the radial direction than the thickness of the lining 28.
• the end region of the fixing ring 54 can be bent easily using a tool which is inserted into the combustion chamber 2 from right to left and which e.g. has an outer inclined surface for exerting the bending pressure.
• FIG. 16 shows an exemplary embodiment in which the lining 28 is again pot-shaped, to the extent similar to FIG. 1. However, FIG. 16 illustrates the case in which the end boundary wall
• annular gap 64 is formed between a flame tube 58 adjoining the combustion chamber 2 and a flame shield component 60 fastened to the flame tube 58. 16 right end of the lining 28 in the described annular space 64 and is clamped slightly bent between the end region of the circumferential boundary wall 8 and the flame shield component 60 serving as a fixing ring.
• the flame tube 58 is with the
• Combustion chamber component 2 welded.
• a ring 32 projects from the end boundary wall 4 to the inside of the
• Combustion chamber 2 but diagonally outwards radially.
• the liner 28 is slightly larger than that Diameter of the ring 52 at its free end. As a result, the liner 28 could be easily inserted into the combustion chamber component 2 in the axial direction from right to left in FIG. 16. Apart from the mechanical fixation described at the right end, the liner 28 has a few weld spots on the circumferential
• the described oblique course of the ring 32 has the advantage that fuel which may drip from the left end region of the lining 28 in FIG. 16 is passed on in the groove formed by the ring 32 in such a way that it does not drip onto the air supply nozzle 10.
• the ring 32 has a function very similar to that of the protective ring 32 in the exemplary embodiment according to FIG. 1.
• the fixing ring 54 and / or the fixing ring 66 or 68 need not extend continuously over the entire circumference, but rather in circumferentially spaced apart
• Sections can be broken. This interrupted training even has advantages when it comes to clamping the liner 28 by bending material areas.
• FIG. 17 shows a combustion chamber investment casting component in a schematic form
• Jacket 84 of the heater a heat exchanger wall 86, the space, in which the combustion takes place, separates it from a water-flowed space inside the jacket, and an exhaust pipe 88 through which the combustion exhaust gases flow away from the heater.
• outer end face is in a recess of the
• Investment casting component a temperature sensor 90 of very common design, e.g. Type PT 1000 attached.
• the blower housing 80 has a through bore 92 at the attachment point of the temperature sensor 90.
• the temperature sensor 90 is fastened by means of a spring clip 94, which is fastened to the blower housing 80, and pressed against the material of the investment casting component.
• the investment casting component In the area of the investment casting component, where the recess 96 for the temperature sensor 90 is on the outside, the investment casting component has an integrally molded heat-conducting finger 98 on the inside, which extends from its root on the front wall of the precision casting component in the axial direction.
• the thermal finger 98 has an axial length in the range from 20 to 90% of the axial length of the circumferential boundary wall 8.
• the temperature in the annular space 100 drops between the circumferential boundary wall 8 or the flame tube 58 and the heat exchanger wall 86. This decrease in the temperature is brought to the place of the heat transfer finger 98
• Temperature sensor 90 passed. If the temperature falls below a certain threshold, the heater is switched off, primarily the fuel supply to the heater. With the aid of the temperature sensor 90, it can also be seen whether the heater has ignited correctly after starting, because igniting the fuel evaporated in the combustion chamber quickly results in an increase in temperature in the annular space 100 described.
• the combustion chamber (2) according to the invention for example the combustion chamber (2) according to FIG. 1, can be inserted into the end of the particle filter housing and through a fuel pump and a combustion air blower to the burner be completed.
• a flame tube with a greater axial length than the combustion chamber (2) usually follows, often after a diaphragm-like cross-section narrowing. At the end of the flame tube, the hot exhaust gas flow is deflected outwards by 180 ° and flows in axial direction on the tubular partition

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Processes For Solid Components From Exhaust (AREA)
• Wick-Type Burners And Burners With Porous Materials (AREA)
• Air-Conditioning For Vehicles (AREA)

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• 1995
  • 1995-05-06 US US08/666,536 patent/US5993197A/en not_active Expired - Fee Related
  • 1995-05-06 CN CN95191089A patent/CN1137778A/zh active Pending
  • 1995-05-06 WO PCT/DE1995/000614 patent/WO1995031348A1/de active IP Right Grant
  • 1995-05-06 CA CA002180858A patent/CA2180858A1/en not_active Abandoned
  • 1995-05-06 CZ CZ962311A patent/CZ285196B6/cs not_active IP Right Cessation
  • 1995-05-06 EP EP95917287A patent/EP0758959A1/de not_active Withdrawn

Non-Patent Citations (1)

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