DE20023560U1 - Fuel fired burner has the input air passed through a pre-heating space to increase the burn efficiency - Google Patents

Abstract

A fuel fired burner, e.g. for burning off collected carbon from an exhaust filter, has a burn chamber lined with heat resistant walls and fed with a fuel and air mixture. The air is pre-heated by passing through a pre-heating space either at the end (38) of the burn chamber, and/or through a concentric jacket (56) around the burn chamber. The airflow is controlled through the pre-heating spaces for improved efficiency.

Description

The The invention relates to a device according to the preamble of the claim 1.

burner of the type mentioned are known to be used to a flame to produce, with the help of fire-resistant exhaust or soot filters be cleaned by burning out. Such exhaust filters are used for cleaning combustion gases, in particular for filtering out of soot particles from combustion gases from diesel engines. In the pores of such, ceramic exhaust filters settle over time soot particles and the like. Burned out after some operating time using the burner and thus be cleaned. The well-known burners and stoves Although ensure satisfactory Cleaning results, however, the fuel consumption is relatively high.

The The object of the present invention is a device of the type mentioned above, with a lower Fuel consumption and thus a high efficiency can be achieved can.

The Invention solves the object with the subject of the claims.

The Advantages of the device according to the invention consist essentially in the fact that the preheating of Combustion air a low fuel consumption and thus a higher Efficiency of combustion is achieved. In the case of the Use of the burner for a furnace for cleaning soot filters of diesel engines as a whole a lower fuel consumption can be achieved.

A particularly preferred embodiment is characterized in that the preheating device as a preheating chamber is formed, by which preferably a partial flow of the combustion air can be passed before introduction into the combustion chamber. A preheating chamber let yourself produce with little effort. It is particularly preferred that the preheat chamber is arranged immediately adjacent to the combustion chamber, so that the preheating by heat transfer from the combustion chamber to the preheat chamber he follows. There are no additional ones Heat generating means necessary, but the preheating the combustion air, preferably a partial flow, as a secondary air flow can be referred to, by means of the combustion self-generated heat energy. The burner is thus easy and inexpensive to produce.

According to one alternative embodiment suggested that the preheat chamber a peripheral wall of the combustion chamber completely or partially wrapped.

Especially is appropriate it that in between the preheat chamber and the combustion chamber arranged wall portion of the combustion chamber at least one air supply duct is formed by the preheated combustion air from the preheating flow into the combustion chamber can.

Corresponding A preferred development is proposed that the preheat chamber a front end of the combustion chamber is arranged. in this connection are several air supply ducts in one End wall of the combustion chamber formed by which combustion air from the preheat chamber can be introduced directly into the combustion chamber.

A further increase of the efficiency leaves can be achieved in that the air supply ducts are arranged obliquely in the wall section are so that the gases and / or fuel contained in the combustion chamber into a current offset with tangential component relative to a longitudinal axis of the combustion chamber become. In this way creates a swirling flow and a swirling and especially cheap Introduction of the combustion air into the combustion chamber. Will the preheated air in a preheat chamber introduced, in which introduced the fuel in gaseous and / or liquid form is carried out in the precombustion chamber due to the swirl flow a particularly intensive mixing of the fuel with the combustion air, which favorably influences the entire combustion.

tries have shown that the air supply channels preferably approximately circular relative to a longitudinal axis the preferably cylindrical combustion chamber are arranged, and Although particularly preferably approximately centrally between the longitudinal axis the combustion chamber and a peripheral wall, so that the swirl flow particularly is generated efficiently.

In order to the fuel is introduced near the air supply channels is preferably a tubular, the fuel inlet opening having Fuel inlet nozzle radially on a peripheral wall of the combustion chamber arranged at a front end. The inlet nozzle opens preferably in the pre-combustion chamber, in which the secondary air flow is introduced through the air supply channels.

According to a further aspect of the invention or a preferred embodiment, a pre-combustion chamber arranged eccentrically to a longitudinal axis of the combustion chamber is proposed, in which intensive mixing and already a first combustion of the fuel takes place with the aid of the preheated combustion air. By the ex Centric arrangement of the pre-combustion chamber, this is partially separated from a subsequent in the flow direction of the gas main combustion chamber, in which also combustion air is introduced, which favors a particularly favorable mixing of the fuel with the preheated air. The eccentric arrangement can be achieved by producing the entire combustion chamber from a one-piece heat-resistant material, for example stainless steel, by eccentric machining. Preferably, the air supply channels formed in the end wall of the combustion chamber open into the pre-combustion chamber, so that the preheated combustion air can be introduced into the pre-combustion chamber.

According to one further aspect of the invention or a preferred embodiment It is suggested that a completely or partially circumferential projection to hold back not completely burnt Fuel is arranged inside the wall of the combustion chamber. One such a lead ensures that accumulates approximately in the bottom area of the combustion chamber, yet unburned liquid Fuel held back there will and not in the subsequent Cleaning room passes, but instead with time in the Burner is burned, so that in turn improves the efficiency becomes. The advantage can be easily achieved by that he formed as a ring and in a the air inlet opening opposite End region of the combustion chamber is arranged.

One Another aspect of the invention or a preferred embodiment is characterized in that a flow guide for conducting the gas flow is arranged inside the wall of the combustion chamber. The flow and thus the burning can be varied in a structurally simple manner. In particular, can be Achieve that the flame image is uniform, which in turn improves the efficiency and possibly the burning out and cleaning of an exhaust soot filter improved.

Especially it is preferred that the flow guide spirally extends on a peripheral wall of the combustion chamber and a plurality of spiral Strömungsleitbleche are arranged inside on the peripheral wall of the combustion chamber.

A another embodiment is characterized by the fact that a rotatable about its longitudinal axis air inlet protrudes into the combustion chamber. Due to the rotation, the flow direction be varied in a simple way. The air inlet nozzle is in the region of its end arranged in the combustion chamber, that the introduced combustion air at least partially in axial Direction - related on a longitudinal axis the combustion chamber - flows.

By This measure let yourself affect the combustion, especially the temperatures within the combustion chamber. The wall temperatures can advantageously considerably be lowered: while at conventional Burners could be the wall red glowing in the operation, this can now be largely avoided. This can high combustion temperatures of up to 1300 degrees in the flame can be achieved without that casing gets too hot. Preferably, the air inlet nozzle is a cylindrical Pipe whose peripheral wall in the region of the arranged in the combustion chamber Partially removed.

at Another aspect of the invention is in a burner of the above mentioned type proposed that two with a common air duct connected separate feed lines to combustion air inlet openings to lead and that in at least one of the separate supply lines of the free flow cross-section can be reduced by a replaceable insert body. The relationship of a Secondary air flow and a main air flow in a pre-combustion chamber or a main combustion chamber leaves vary in this way simply but effectively by inserting or replacing the insert body.

This is preferably formed as a passage formed a threaded sleeve, the by means of an external thread can be screwed into an internal thread of the separate feed line.

With Help the combustion process of the invention In essence, the advantages described above are achieved.

The The invention is described below by means of embodiments with reference described on the drawings. Show it:

1 a furnace with a burner according to the invention in a partial sectional view;

2 a burner according to the invention in a sectional view;

3 another sectional view of the burner after 2 ;

4 another sectional view of the burner;

5 another sectional view of the burner;

6 an alternative embodiment of a burner according to the invention in a section presentation;

7 an alternative embodiment of a burner according to the invention with flow baffles;

8th another view of the burner 7 ;

9 an end view of the burner according to 7 ;

10 a sectional view of an alternative burner with a rotatable air inlet nozzle of a sectional view;

11 the separate air inlet in a side view.

1 shows a device for cleaning exhaust gas filters or particle filters with a burner according to the invention 2 , In a housing 4 are several ceramic filter modules 6 attached, through whose open-pored inner structure to be cleaned exhaust gas of an internal combustion engine, in particular a diesel engine flows, which passes through a conduit 8th in the interior of the case 4 is initiated. During the flow, soot particles and other combustion residues in the filter modules 6 retained. After a certain period of operation, the burner 2 turned on, and the particles and combustion residues are passed through one of the burner 2 produced flame or hot combustion burned so that the filter modules 6 getting cleaned.

The burner 2 is centered on a central axis 9 by means of a holder in the housing 4 attached. Through a fuel line 10 for liquid (diesel) fuel, an adjustable amount of fuel per unit time in a radially projecting fuel inlet nozzle 12 , which can also be referred to as a candle neck, and through this into the interior of a combustion chamber 14 of the burner 2 through a fuel inlet port 16 , see. also 2 , be initiated. The walls of the combustion chamber 14 Made of stainless steel or other heat resistant materials.

As in particular from 2 As can be seen, the liquid fuel first flows into a porous, sintered distribution ring 18 that in the neck 12 is pressed in, and from there through the inlet opening 16 in the interior of the combustion chamber 14 , In the neck 12 further protrudes a glow plug 20 for preheating and vaporizing the incoming fuel.

The substantially cylindrical combustion chamber 14 includes a - with respect to a longitudinal axis 23 - cylindrical pre-combustion chamber 24 and an adjacent, cylin drisch - based on a longitudinal axis 25 - trained main combustion chamber 26 , through the outlet opening 28 the combustion gases can flow out. The fuel passes substantially radially through the inlet port 16 in the pre-combustion chamber 24 one.

Combustion air or other oxygen-containing gases occur on the one hand in a partial flow, which can be referred to as a secondary air flow, by a plurality of in an end-side, circular disk-shaped wall section 30 formed, cylindrical air supply ducts 32 in the pre-combustion chamber 24 one. By a tangential to the longitudinal axis 25 extending combustion air supply line 34 , see. 1 . 3 and 5 For example, a partial flow of the combustion air, which may be referred to as a main air flow, through an air inlet port 36 (see. 2 ) in the main combustion chamber 26 introduced, so that a combustible mixture of fuel and combustion air is formed. By means of a from the outside into the interior of the main combustion chamber 26 leading measuring channel 38 can a temperature gauge such as a thermocouple in the main combustion chamber 26 be introduced to determine the temperature there.

An inventive preheating device for preheating the combustion air prior to feeding or introduction into the combustion chamber 14 is through a frontal to the pre-combustion chamber 24 arranged preheat chamber 38 formed in which a partial flow of the combustion air, namely in the pre-combustion chamber 24 preheated secondary air flow is preheated. The preheating chamber is through the circular disk-shaped wall section 30 and a lid spaced therefrom 40 and one on the lid 40 trained ring 42 limited. The preheating by the preheating chamber 38 and then through the air supply channels 32 The heat energy required by the flowing combustion air is dissipated by the heat in the combustion chamber 14 contained combustion gases on the wall section 30 , by heat conduction through the wall section 30 through and then by giving the heat to the in the preheating chamber 38 transmitted combustion air transmitted. The thickness of the wall section 30 is chosen so that there is sufficient strength and good heat conduction and heat storage capacity.

How out 4 it can be seen are several Lufzuführkanäle 32 in the wall section, which can also be referred to as a swirl plate 30 formed, the uniformly spaced from each other on a concentric to the longitudinal axis 23 the pre-combustion chamber 23 arranged circle line 44 lie. They are approximately midway between the longitudinal axis 23 and a peripheral wall 46 the combustion chamber 14 placed. As cylindrical bores arranged air supply ducts 32 are slanted in the wall section 30 arranged, such that their longitudinal axes inclined to the wall portion 30 and related to the longitudinal axis 23 , Each air supply duct 32 is tangent to the circle 44 inclined, at an angle of about 25 degrees. Of course, another angle of inclination could be realized. Due to the inclined arrangement creates a swirl flow with tangential component in the pre-combustion chamber 24 , relative to the longitudinal axis 23 , By such a swirl flow, there is a particularly good mixing and turbulence of the gases within the combustion chamber 14 and to a particularly good mixing of the through the inlet opening 16 in the pre-combustion chamber 24 entering fuel, so that overall affect the combustion low and good fuel utilization is achieved.

The combustion is further favorably influenced by the fact that the pre-combustion chamber 24 eccentric to the main combustion chamber 26 is arranged, as from the in the 2 and 3 recognizable distance E of the longitudinal axes 25 is visible to each other. The entire combustion chamber 14 is with the exception of the wall section 30 , the lid 40 and the neck 12 essentially made of a single piece of material produced by machining, such as milling or turning, so that a high strength is achieved and the eccentric arrangement of the pre-combustion chamber 24 in a relatively simple way. Due to this eccentric arrangement is a radially outward relative to the main combustion chamber 26 staggered room 50 in the pre-combustion chamber 24 formed, in which substantially the fuel through the inlet opening 26 is initiated. In interaction with the swirl flow in the pre-combustion chamber 24 As a result, a particularly good mixing and thus combustion takes place. In the area of the room 50 it is preferable to ignite the combustion.

As 2 is inside the wall of the main combustion chamber 26 a completely circumferential projection or ring 52 provided, not completely burned, in particular liquid fuels in the main combustion chamber 26 withhold. In addition, the ring influences 52 the flow of combustion gases in the main combustion chamber 26 in that it provides for a slight constriction of the free flow cross-section and thus the combustion within the main combustion chamber 26 "Holds". The ring 52 is substantially opposite to the air inlet openings in the air supply ducts 32 and opposite the air inlet opening 36 arranged.

6 illustrates an alternative embodiment of a burner according to the invention, which has a number of similarities to the previously described burner; With respect to like parts, like reference numerals have been used and reference is made to the above descriptions.

In addition to the preheat chamber 38 for a secondary air flow and the main air flow through the schematically illustrated inlet opening 36 into the combustion chamber 14 enters, with one adjacent to a peripheral wall 54 the combustion chamber 14 in the embodiment of the main combustion chamber 26 be arranged and envelop these. This additional preheat chamber 56 is through a cylindrical peripheral wall 58 limited to the outside. The combustion air is first in the preheat chamber 56 passed and then out of this by an opening in the peripheral wall 54 the combustion chamber 14 into the interior of the main combustion chamber 26 initiated. By such preheating due to heat transfer from the interior of the combustion chamber 14 on the in the preheat chamber 56 contained gases a more favorable combustion is achieved.

7 to 9 illustrate another embodiment of a burner according to the invention, which has a number of similarities to the previously described burners; With respect to like parts, like reference numerals have been used and reference is made to the above descriptions.

In 7 it can be seen that an air supply line connected to a common air line 60 to the pre-combustion chamber 24 leads and another separate air supply line 62 into the main combustion chamber 26 leads, in the latter a screw-insert body is introduced to selectively vary the free flow area to the partial air flows in the lines 60 . 62 be able to bring by varying the flow resistance in a predeterminable ratio in order to influence the combustion optional.

As the 7 to 8th illustrate are in the combustion chamber 14 in the area of the main combustion chamber 24 inside on the wall as flow baffles 64 . 66 trained flow guide attached, for example, welded, which the gas flow within the combustion chamber 14 and thus favorably influence the flame image. In particular, the through the feed line 62 inflowing main air flow is due to the spiral Strömungsleitbleche 64 . 66 brought to an at least spiral flow path, whereby the combustion and the flame image uniform.

That partly in the 10 and 11 Darge illustrated alternative embodiment of a burner according to the invention is in the region of the air inlet of the main air flow in the main combustion chamber 26 the combustion chamber 14 modified so that one around a longitudinal axis 68 rotatable, in a tube 70 used air intake 72 a simple adjustable air intake made possible by turning the air inlet 72 around the longitudinal axis 68 , In a desired rotational position, the air inlet 72 with the help of a fixing ring 74 ( 11 ). At one of its outlet 76 opposite end is a threaded sleeve 78 shrunk into an internal thread of the pipe 70 is screwed. The air inlet 72 can of course in different axial positions and thus different distances in the main combustion chamber 26 positioned in a prominent position and then with the help of the ring 74 be fixed. It is designed substantially as a tube and has in its end a separate peripheral wall and thus a half-shell-like peripheral wall 80 on, wherein the end by a half-round in plan view wall portion 82 partially closed. The design allows combustion air to be partially in the axial direction with respect to the longitudinal axis 25 flow into the combustion chamber.

The combustion method according to the invention is explained below with reference to the figures. Liquid fuel is passing through the supply line 10 in the neck 12 and then through the inlet 16 introduced into the combustion chamber. A secondary air flow is first in the preheat chamber 38 is initiated and heated there and then flows through the air supply channels 32 with a tangential flow component into the pre-combustion chamber 24 and there is mixed with the fuel. The mixture ignites and flows into the combustion chamber 26 and burns completely there. Subsequently, the combustion gases pass through the outlet opening 28 out of the burner. Another partial air flow of the combustion air is through the air line 34 and the entrance opening 36 into the main combustion chamber 26 initiated and ensures complete combustion.

In the separate supply lines connected to an air pressure source to the preheating chamber 38 or the inlet opening 36 is set due to the flow resistance in these separate supply lines, the ratio of the volume or flow rates of the two partial streams, which are branched off from a common air line. In order to be able to vary this quantitative ratio in a simple manner, a replaceable insert body for reducing or expanding the free flow cross section of this supply line can be installed in one of the supply lines. The insert body is preferably designed as a threaded sleeve which can be screwed into a thread of one of the feed lines.

Claims (29)

Device for cleaning exhaust gas filters or particle filters with an exhaust gas filter, particle filter or soot filter device ( 6 ) and with a burner ( 2 ) which is designed as a firing device for cleaning by burning out the exhaust gas filter or Rußfiltereinrichtung, wherein the burner ( 2 ) a combustion chamber ( 14 ) whose walls are made of heat-resistant material, a fuel inlet opening ( 19 ) for supplying preferably liquid fuel into the combustion chamber ( 14 ) and an air inlet opening ( 36 ) for supplying combustion air into the combustion chamber ( 14 ), characterized in that the burner ( 2 ) a preheating device for preheating the combustion air before being fed into the combustion chamber ( 14 ). Apparatus according to claim 1, characterized in that the preheating device as a preheating chamber ( 38 . 56 ) is formed, through which preferably a partial flow of the combustion air prior to introduction into the combustion chamber ( 14 ) can be passed. Apparatus according to claim 2, characterized in that the preheating chamber ( 38 . 56 ) immediately adjacent to the combustion chamber ( 14 ) is arranged so that the preheating by heat transfer from the combustion chamber ( 14 ) to the preheat chamber ( 38 . 56 ) he follows. Apparatus according to claim 3, characterized in that the preheating chamber is a peripheral wall of the combustion chamber ( 14 ) completely or partially wrapped. Apparatus according to claim 4, characterized in that in a between the preheating chamber ( 38 . 56 ) and the combustion chamber ( 14 ) arranged wall portion of the combustion chamber ( 14 ) at least one air supply channel is formed by the preheated combustion air from the preheating chamber ( 38 . 56 ) in the combustion chamber ( 14 ) can flow. Apparatus according to claim 5, characterized in that the preheating chamber ( 38 ) at a front end of the combustion chamber ( 14 ) is arranged. Apparatus according to claim 6, characterized in that a plurality of air supply channels ( 32 ) in an end wall of the combustion chamber ( 14 ) educated are, by which combustion air from the preheating chamber ( 38 ) directly into the combustion chamber ( 14 ) can be introduced. Device according to one of claims 4 to 7, characterized in that the air supply channels ( 32 ) are arranged obliquely in the wall section, so that in the combustion chamber ( 14 ) and / or the fuel into a flow with tangential component with respect to a longitudinal axis of the combustion chamber ( 14 ). Device according to one of claims 4 to 8, characterized in that the formed in the end wall air supply channels ( 32 ) approximately on a circle about a longitudinal axis ( 23 ) of the combustion chamber ( 14 ) are arranged. Apparatus according to claim 9, characterized in that the air supply channels ( 32 ) approximately centrally between the longitudinal axis ( 32 ) and a peripheral wall ( 46 ) of the combustion chamber ( 14 ) are placed. Device according to at least one of the preceding claims, characterized in that a tubular, the fuel inlet opening ( 16 ) having fuel inlet port ( 12 ) radially on a peripheral wall ( 46 ) of the combustion chamber ( 14 ) is arranged at a front end. Device according to at least one of the preceding claims, characterized in that the fuel inlet port ( 12 ) in a pre-combustion chamber ( 24 ) opens. Device according to the preamble of claim 1 or one of the preceding claims, characterized by an eccentric to a longitudinal axis ( 25 ) of the combustion chamber ( 14 ) arranged pre-combustion chamber ( 24 ). Apparatus according to claim 7 or 12 or 13, characterized in that in the end wall of the combustion chamber ( 14 ) formed air supply channels ( 32 ) in the pre-combustion chamber ( 24 ), so that the preheated combustion air into the pre-combustion chamber ( 24 ) can be introduced. Device according to the preamble of claim 1 or one of the preceding claims, characterized in that a completely or partially circumferential projection for the retention of incompletely burned fuel inside the wall of the combustion chamber ( 14 ) is arranged. Apparatus according to claim 15, characterized in that the projection as a ring ( 52 ) and preferably in one of the air inlet opening ( 36 ) opposite end region of the combustion chamber ( 14 ) is arranged. Device according to the preamble of claim 1 or one of the preceding claims, characterized in that a flow guide for guiding the gas flow inside the wall of the combustion chamber ( 14 ) is arranged. Apparatus according to claim 17, characterized in that the flow guide element spirally on a peripheral wall ( 46 ) of the combustion chamber ( 14 ) runs. Apparatus according to claim 18, characterized in that a plurality of spiral Strömungsleitbleche inside of the peripheral wall ( 46 ) of the combustion chamber ( 14 ) are arranged. Device according to the preamble of claim 1 or one of the preceding claims, characterized that one around its longitudinal axis rotatable air inlet nozzle protrudes into the combustion chamber. Apparatus according to claim 20, characterized in that the air inlet nozzle is designed in the region of its arranged in the combustion chamber end so that the introduced combustion air at least partially in the axial direction - with respect to a longitudinal axis ( 25 ) of the combustion chamber ( 14 ) - flows in. Apparatus according to claim 21, characterized that the air inlet nozzle is a cylindrical tube whose Circumferential wall in the region of the arranged in the combustion chamber end partially removed. Device according to the preamble of claim 1 or one of the preceding claims, characterized in that two separate supply lines connected to a common air line to combustion air inlet openings ( 32 . 36 ) and that in at least one of the separate supply lines, the free flow cross-section can be reduced by a replaceable insert body. Device according to claim 23, characterized in that that the insert body as a threaded sleeve is formed, which in a thread of the separate feed line can be screwed. Device according to the preamble of claim 1 or any one of the preceding claims, characterized in that the air supply ducts ( 32 ) are arranged obliquely in the wall section, so that in the combustion chamber ( 14 ) and / or the fuel into a flow with tangential component with respect to a longitudinal axis of the combustion chamber ( 14 ). Device according to the preamble of claim 1 or any one of the preceding claims, characterized in that the air tangentially into the combustion chamber ( 14 ) is introduced and the gases and / or the fuel in a flow with a tangential component with respect to a longitudinal axis of the combustion chamber ( 14 ). Device according to the preamble of claim 1 or any one of the preceding claims, characterized in that a tubular, the fuel inlet opening ( 16 ) having fuel inlet port ( 12 ) radially on a peripheral wall ( 46 ) of the combustion chamber ( 14 ) is arranged at a front end. Device according to the preamble of claim 1 or any one of the preceding claims, characterized in that the fuel inlet nozzle ( 12 ) in a pre-combustion chamber ( 24 ) opens. Device according to the preamble of claim 1 or according to one of the preceding claims, characterized in that the air inlet nozzle is designed in the region of its arranged in the combustion chamber end so that the introduced combustion air at least partially in the axial direction with respect to a longitudinal axis ( 25 ) of the combustion chamber ( 14 ) flows in.