EP0970327B1 - A boiler fitted with a burner - Google Patents

Abstract

This invention concerns a boiler fitted with a burner suitable for wall heaters or built-in kitchen heaters in which a mantle-shaped heat exchanger made of pipe elements connected in parallel and/or series divides the boiler chamber into a combustion chamber and an exhaust chamber. The heat exchanger has openings for hot flue gases distributed over its mantle. The burner head disposed in the combustion chamber is suitable for burning oil and has a flame tube with an axial flame opening and a flame baffle element disposed at a distance from the flame opening which is constructed so that the flame is diverted into the space between the flame tube and the heat exchanger. In addition, a fire chamber mantle can be disposed between the heat exchanger and the flame tube to protect the heat exchanger from direct contact with the flame.

Description

Technical field of the invention

The present invention relates to a Burner-equipped boiler or instantaneous water heater, with a casing enclosing a boiler room, a jacket-shaped heat exchanger, which converts the boiler room into a Combustion chamber and an exhaust chamber split and over the The lateral surface distributes passages for hot combustion gases has, and one arranged in the combustion chamber Burner head according to the preamble of patent claim 1.

State of the art

In the French Patent No. 93 00498 are a series of arrangements of boilers recorded some of the features listed above exhibit. However, these boilers are designed for gas burners, which has a cylindrical jacket that is closed at the end have distributed on the lateral surface of a plurality of Flame openings are arranged. Such a gas boiler or instantaneous water heater is very space-saving and required no separate boiler room.

There has been a need for such a long time space-saving heating system, which uses the fuel oil can be operated. A disadvantage of gas as a fuel is that its inventory is significantly more expensive than the supply of oil. So is gas firing either to an expensive pressure tank or a connection to one Distribution network for gas, whereas oil is already in Thousands of tanks installed easily and in sufficient quantity is stored on site. Also the supply or filling the oil tank with oil is essential easier and less dangerous than with gas.

GB-A-792 747 discloses a boiler with one Boiler room, which is made up of a heat exchanger special coiled pipe into a pipe wrapped by the heat exchanger Fire chamber and an exhaust gas chamber surrounding the heat exchanger divides. Opposite an arranged on the front, Fireclay flame pot, in which for the commissioning of the Arrange a boiler head, not shown, in the boiler is a head assembly is formed on which the hot gases are redirected and swirled. Through the Turbulence gets unburned gases from the periphery back to the central flame. The influx of fresh ignited air / fuel mixture into the combustion chamber creates an overpressure with which the exhaust gases openings between the windings of the heat exchanger tube in a ring channel outside the heat exchanger become. The exhaust gases can be close to the head arrangement get into a first ring channel, in this to Flow on the burner side and in a second outer ring channel back again. In a simpler embodiment they reach the burner side within the combustion chamber, and step through the openings into the ring channel. In this The flue gas flows in the other direction again to a fireplace. A burner head is inside the flame pot to arrange which is the heat exchanger before the radiant heat protects the flame and the burner head. A recirculation of the exhaust gas in the flame is only in the boiler room provided outside the flame pot. With one Boilers can therefore only use high fuels Burn exhaust emissions.

From DE-A-32 12 006 a boiler according to the The preamble of claim 1 is known. The boiler is with a vertical spiral tube as a heat exchanger Mistake. On the top of the boiler is a burner head Fall burner arranged. Opposite the fire opening of the The lint burner's flame cup is a concave one Firebrick arranged. To the fireclay and the extending between the fire opening and the fireclay panel Reverse combustion chamber, the heat exchanger is arranged, which an annular one arranged around the heat exchanger Separates the hot gas flue from the combustion chamber. Through the Fireclay is used to return the hot gases to the burner head redirected. The turns of the spiral tube are in one middle area tight. Through increasing openings the gas enters between the end turns of the helical tube the outer hot gas flue, where it is down again and again passed through the heat exchanger into an exhaust pipe becomes

The disadvantage of this boiler is that the temperature the heating gas in the outer heating gas flue is still so high that radiant heat from one that surrounds the heating gas flue and on the Heat exchanger can be transferred.

Object of the invention

It is therefore an object of the invention to To create firing system, which with an oil burner can be operated without being larger than is a gas firing system. In addition, the heating system should an oil or gas burner can be operated. Is further it is the object of the invention to create a furnace, which is characterized by very low emissions and small Heat loss and also a low noise level distinguished.

Description of the invention

According to the invention, this is achieved by the characterizing features of claim 1 reached.

One advantage of the boiler according to the invention is in that it can be heated with burners, which one have lance-shaped flame. Such a flame is needed usually one elongated in the direction of the flame Firebox. An arranged according to the invention Flame deflecting part, however, allows the length of the Shorten the combustion chamber significantly. The deflecting part directs the Flame back to its starting point and shorten it Boiler room about half the length. This is the Combustion chamber almost filled with a flame, which comes from a flame tube in one direction and on the deflection part redirected in the opposite direction burns. Here the rear part of the flame forms an axial core flow and the front part of the flame one around the core flow opposite mantle flow arranged around. The Returning the flame to its root has continued Advantage that immediately after lighting the flame around the There are hot gases around the flame tube, which are suitable for the Improvement of the cold start behavior can be used. Another advantage is that by turning the flame Furnace is better used and more compact than with a long, thin flame shape. In particular the entire length of the firebox is practically uniform suitable for heat transfer to a heat exchange medium, because the burning head is covered by the flame.

The heat exchanger advantageously has at or near at least one end of a final organ, which the Combustion chamber limited in the longitudinal direction. This is in addition to the exhaust gas chamber around the heat exchanger formed yet another chamber in which exhaust gas from the Exhaust chamber flows. This exhaust gas is now through the Heat exchanger is already cooled and can be used to cool the flame partly recirculated into the flame tube and partly through a chimney be drained. A closing body advantageously divides its side facing away from the combustion chamber from the boiler room outflow chamber connectable with a chimney. Such Outflow chamber lies axially in the boiler. So she takes it Flue gas from the periphery evenly. Unilateral Loads on the heat exchanger can thus be avoided. A closing organ from the boiler room advantageously divides one Recirculation chamber. Through this recirculation chamber Cooled exhaust gas can be used to cool the flame into the flame tube be recirculated. The recirculation chamber can also be the outflow chamber. It is advantageous the exhaust gas discharge chamber partitioned off by a closing element or / and the recirculation chamber from the heat exchanger encased. As a result, what flows into these chambers becomes Exhaust gas additionally cooled before it leaves the boiler room or performs its cooling task. The exhaust gas is through the double contact with the heat exchanger up to about 80 Degrees cooled, even under continuous operation Full performance. This allows the flue gas to go directly to the boiler be drained into a plastic fireplace.

The closing body advantageously points between Combustion chamber and exhaust gas outflow a bulge for Exhaust gas outflow chamber open to extend the combustion chamber and the outflow chamber does not take up too much space claimed. Expediently through such Bulge the heat exchanger area around the Exhaust gas outflow chamber in relation to its volume kept large.

The flame deflecting part advantageously forms Closing organ, so the number of parts required can be reduced. In addition, the arrangement of the Deflection part at a distance from the housing wall also acoustic Benefits. This closing body is expediently or Flame deflection part bulged out towards the outflow chamber. In the Bulge expediently occurs the deflection of the Flame without involving heat exchanger elements, and the entire heat exchanger area can be used because the deflecting part has no openings for hot flue gas covered. The flame deflecting part expediently has one on the flame axis, the flame opposing flame dividers and one around them annular deflection channel. The flame divider divides the Flame apart and the deflector guides the flame parts so that their flow direction is turned through 180 °. The Deflection channel is advantageously uniform all round designed so that the flame even after the deflection has a uniform shape.

The jacket of the heat exchanger advantageously consists of with space next to each other, which the combustion chamber arranged extensively and to a feed and a Discharge are connected. These are expediently Heat exchanger tubes wound helically. Such a heat exchanger jacket is easy to manufacture, exhibits a large surface and passages between the pipes on. In addition, compared to castings, pipes can a smaller wall thickness and thus a more dynamic one Have heat transfer, which is characterized by a higher Performance noticeable in a small footprint. The jacket of the heat exchanger is advantageous from a A plurality of heat exchanger units put together. The Individual heat exchanger units face each other a heat exchanger with a single one, but all the longer Pipe, a smaller length of pipe, causing the Flow rate can be increased.

The heat exchanger units are expedient therefore connected in parallel to the inlet and outlet. With Heat exchanger units according to the in French Patent No. 93 00498 Heat exchanger elements applied. These stand out other by a flattened pipe cross-section, which rounds out the exchange surface Cross sections is also enlarged. Amongst other things there is a significant advantage to using them Heat exchanger units also in that their production is already running for gas water heaters and therefore in excellent quality available on the market.

The burner is advantageous for exhaust gas recirculation equipped to meet the exhaust gas values prescribed today, especially in the case of frequent cold starts. Even if gas burners are used in the boiler according to the invention can find, so the burner is advantageous Oil burners because oil can be stored in simple tanks and these can easily be refilled. The dependence from a pipeline network can thus be avoided. The Handling oil is also much less dangerous than the handling of gas which, so it is not through a network is distributed under pressure in appropriate pressure tanks must be filled.

The burner is advantageously switchable or switchable on gas operation. If the burner head for both oil and oil Alternatively, these two media can be used with gas little additional installation effort, in the same Plant can be used. This has the advantages that e.g. on Price developments that can be responded to are higher Security against delivery bottlenecks exists or through Installation of a temporary oil tank on a projected creation of a gas supply line can, etc.

One advantageously sprays when the burner is operated with oil Oil nozzle to evaporate the oil into the flame tube recirculated exhaust gas and are the inlet openings in the Flame tube for the air or the exhaust gas designed such that the air and the exhaust gas are in a hollow cylindrical or a frustoconical vortex zone. That with oil mixed with the exhaust gas has completely evaporated, before it is mixed with the air. This results in very advantageous exhaust gas values and an excellent Starting behavior of the burner.

When the burner is operated with gas, an air supply duct is expediently designed as a mixing tube for the admixture of gaseous fuel. The inlet openings in the flame tube for the fuel / air mixture or the recirculated exhaust gas are advantageously designed such that the fuel / air mixture and the exhaust gas mix in a hollow cylindrical or frustoconical vortex zone. Due to these similar methods, the same flame tube can be used for both oil and gas. The oil nozzle can even remain in the system during gas operation or the gas supply means during oil operation, so that there is a two-media firing system with a single burner. In addition, these burners achieve exhaust gas values of less than 60 mg NO _x per kW for oil and less than 20 mg NO _x for gas. The CO values of 16 mg / kW are also at a low level. Apart from this, excellent cold start behavior is achieved with this burner.

It is advantageous in the combustion chamber between the combustion tube or deflected flame and heat exchanger a cylindrical Flame chamber jacket arranged, which passages for hot Has smoke gases. This flame chamber jacket ensures one even distribution of the hot smoke gases to the Heat exchanger and forms an ash catcher. It protects the Heat exchanger before direct contact with the flame. Thereby the distance between the flame and the heat exchanger can be very small being held. This flame chamber coat also has an effect positive on noise insulation. They are advantageous Passages arranged so that the flue gases are approximately tangential flow out of the flame chamber jacket because they are in one common direction of rotation ordered the heat exchanger jacket flow through tangentially. This is the Heat transfer versus radial heat transfer Flow direction improved.

The housing advantageously has an installation in Enabling wall heater or plug-in kitchen unit Dimensions on. The housing with air supply and exhaust duct can have a length of up to approx. 50 cm. A the short version comes with a good 30 cm boiler length. This allows for a separate room for this heater to be dispensed with. It can be stored in a closet become. A supply air line in counterflow is advantageous the flue gas pipe arranged to allow the air to pass through the waste heat is preheated in the flue gas. This is expedient Blower arranged next to the housing and a supply air duct from Fan on one end of the housing and on the burner head led to the length or depth of the plant as small as possible to keep.

Are advantageous on the end faces of the combustion chamber fireproof panels with a labyrinthine inner structure arranged. These protect the metal parts behind, isolate the housing from the heat of the flame and dampen the burner's noise emissions. Conveniently is an end face of the housing by a removable Lid closed. The burner on the lid is advantageous attached. This makes the boiler room and the burner light accessible.

Essential housing parts are expedient and / or the heat exchanger made of austenitic stainless steel manufactured, which is resistant to the aggressive exhaust gases and condensates.

Brief description of the figures

Fig. 1

vier schematische Anordnungen von Heizkesseln,

Fig. 2

ein Ausführungsbeispiel eines erfindungsgemässen Heizkessels, im Längsschnitt,

Fig. 3

ein Ausführungsbeispiel eines erfindungsgemässen Heizkessels mit Flammraummantel, im Längsschnitt,

Fig. 4

ein Ausführungsbeispiel gemäss Figur 3, im Querschnitt,

Fig. 5

den Öl-Brennerkopf im Längsschnitt,

Fig. 6

schematisch das Verbrennungsverfahren bei flüssigem Brennstoff,

Fig. 7

Aufsicht auf einen Blendeneinsatz mit ausgeschnittenen, jedoch noch nicht verdrehten Führungsflächen,

Fig. 8

Schnitt durch den Blendeneinsatz nach Fig. 7, wobei die Führungsflächen zur Drallerzeugung verdreht sind,

Fig. 9

den Gas-Brennerkopf im Längsschnitt und schematisch das Verbrennungsverfahren bei Verwendung von gasförmigem Brennstoff.

Exemplary embodiments of the invention are described below with reference to the figures. It shows:

Fig. 1

four schematic arrangements of boilers,

Fig. 2

an embodiment of a boiler according to the invention, in longitudinal section,

Fig. 3

an embodiment of a boiler according to the invention with flame chamber jacket, in longitudinal section,

Fig. 4

an embodiment of Figure 3, in cross section,

Fig. 5

the oil burner head in longitudinal section,

Fig. 6

schematically the combustion process for liquid fuel,

Fig. 7

Supervision of a panel insert with cut out but not yet twisted guide surfaces,

Fig. 8

7 through the diaphragm insert according to FIG. 7, the guide surfaces being twisted to generate swirl,

Fig. 9

the gas burner head in longitudinal section and schematically the combustion process when using gaseous fuel.

Detailed description of the invention with reference to the Embodiments

Figure 1.1 shows a schematically simplified Representation of an embodiment of an inventive Boiler 11 '. A housing 13 is from a heat exchanger 15 divided into a combustion chamber 17 and an exhaust gas chamber 19. A flame tube 23 is on an end face of the combustion chamber 17 arranged and from the flame tube 23 strikes the flame axially 25. supply air flows through a mixing tube 21 into the flame tube 23, burns in the flame 25 and flows as hot Combustion gas or flue gas through passages in the Heat exchanger 15 in the exhaust chamber 19 (arrows). From there The flue gas leaves the exhaust gas space 19 by means of one in FIG. 1 not shown opening in the housing 13. Figure 1.2 shows a variant of this, in which in a boiler 11 " Closing member 27, the combustion chamber 17 limited in length.

The boiler room is thus divided into three zones: the Combustion chamber 17, the exhaust chamber 19 and one Exhaust gas outflow chamber 29. The exhaust gases now flow out of the Exhaust chamber 19 first through the heat exchanger 15 in the exhaust gas outflow chamber 29 and from there through an opening 31 into a fireplace. Figure 1.3 shows a simplified variant of the Figure 1.2, in which the heat exchanger 15, the exhaust chamber 19th does not separate from the outflow chamber 29, but only that Combustion chamber 17 envelops. In Figure 1.2 and Figure 1.3 is by Arrows indicate how exhaust gas recirculates into the flame tube 23 becomes. 1.4 shows a boiler 11 "" in which Boiler room in addition to the final organ 27 Closing member 27 'is arranged, which is a Recirculation chamber 33, so that recirculating Exhaust gas from the combustion chamber 17 through the heat exchanger 15 in the exhaust chamber 19 and again through the heat exchanger 15 through into the recirculation chamber 33 and from there through recirculation openings in the flame tube 23 this is sucked in.

Figure 2 shows a section through a Embodiment of a boiler 11 in turn Heat exchanger 15, combustion chamber 17 and exhaust chamber 19. The flame tube 23 is arranged in the combustion chamber 17, which recirculation openings 35 and a flame opening 37 having. The heat exchanger 15 is made of tubes 40 with a flat Cross section formed, which are wound helically. The tubes 40 are spaced from each other so that in the space 41 between the pipes 40 the exhaust gas Can flow through heat exchanger 15. The heat exchanger 15 consists of individual elements 43, which are parallel and / or are connected in series to an inlet or outlet. The A deflection part 39 is arranged opposite the flame opening 37. This deflection part 39 forms a closure member 27 or is connected to a closure member 27. The closing body 27 sits between two tubes 40 or between two elements 43, so that the hot exhaust gas through the spaces 41 from the combustion chamber 17 into the exhaust chamber 19 and from there again between the pipes 40 into the outflow chamber 29 must flow. The exhaust gas can then flow out of the outflow chamber 29 through the opening 31 into a fireplace or a Step over the exhaust pipe.

The deflection part 39 forms on the axis 45 of the Flame tube 23 or the boiler 11 an increase 47, which opposes the flame and divides it symmetrically. The Flame is through the deflection channel 49 in one of the original direction of flame opposite direction deflected and strikes between the flame tube 23 and the Heat exchanger tubes 40 back against the flame root. This creates an approximately cylindrical flame body of about double the flame tube diameter and the hot exhaust gases are through the entire length of the combustion chamber 17 Gaps 41 conveyed between the tubes 40 where an exchange of energy with that flowing in the tubes 40 Heat transfer medium takes place.

The deflection part 39 is basin-shaped and sits with its bottom 49 near that opposite the flame tube Front of the housing 13. The outer pool rim 51 closes almost flush with the outer channel edge 53 of the Deflection channel 49 between the heat exchanger tubes 40 to this and the pool wall 55 runs obliquely from the edge 51 of the Heat exchanger tubes 40 away, so that none of the tubes 40 through the depth claimed by the deflection part 39 is covered. The the space occupied by the basin-shaped deflection part 39 opens up Cost of the outflow chamber 29, which thereby necessary minimum dimension is reduced. The combustion chamber 17th is opposed by this form of closing body 27 the outflow chamber 29 extended. So that the length of the boiler room can be minimized.

On the burner head end of the boiler 11 a cover 57 is arranged, which is connected to the housing 13 is screwed. The cover 57 has an opening 59 the inside of which is a baffle plate or cover 61 which the flame tube 23 is attached. Around the flame tube 23 around and at a distance from it is an annular disc 63 arranged, which consists of a refractory, porous or felt-like material and therefore an insulating It has an effect on both heat and sound. The same The deflecting part 39 has a structure and thus the same effect.

The flame tube 23 is located near the baffle plate 61 Recirculation openings 35 through which exhaust gas from the Space 65 between heat exchanger 15 and flame tube 23 in the Flame tube to be recirculated. The exhaust gas encased in Flame tube 23 a centrally let air flow. Thereby the flame tube is immediately after the ignition of a flame hot exhaust gas and immediately becomes hot itself. For liquid fuel, an oil nozzle 67 is provided which the fuel through the central air flow into the Exhaust jacket sprays. The fuel evaporates in the exhaust jacket. The vaporized fuel is now together with the exhaust gas swirled in the air. The flame burns blue because of the whole Fuel is gasified before flame formation.

The same burner head can be used for gas operation. Only the gaseous fuel is added to the air, preferably on the vacuum side in the fan. An exhaust gas jacket, recirculated through the recirculation openings 35 in the flame tube 23, surrounds the centrally admitted air / fuel stream, mixes with it in the vortex zone between the jacket and core flow and the flame subsequently burns very similarly to that with gasified liquid fuel fed flame. In both operating modes, the flame tube 23 becomes hot and transfers a certain amount of energy to the heat exchanger 15 by radiation. This effect is desirable, especially because blue-burning flames otherwise emit little radiant energy. The exhaust gas values are very low in both operating modes: The NO _X emissions are below 60 mg / kW in the case of an oil fire and below 20 mg / kW in the case of a gas fire. The CO values are below 16 mg / kW.

Built in the manner just described and working burners are on the same day in the two European applications' procedure and Device for burning liquid fuel "and "Method and device for the combustion of gaseous Fuel "detailed on the Swiss priority applications No. 1997 0718/97 or 0719/97 based.

Figures 3 and 4 show a further embodiment of a boiler according to the invention. Figure 3 is a Longitudinal section, Figure 4 is a cross section of the same boiler. In this boiler 11 "is the closing member 27, for example as a simplified deflecting part without a specific shape designed. Next is the main difference to boiler 11 2 shows a flame chamber jacket 69 on the combustion chamber side of the Heat exchanger 15 arranged in the combustion chamber 17. The Flame chamber jacket 69 points to its cylindrical jacket Slits 71 and baffles 73, which are called Flue gases from the inner area of the combustion chamber 17 released and in a flow rotating about axis 45 through the spaces 41 between the tubes 40 of the Conduct heat exchanger 15 (arrows in Fig. 4). The flame now strikes between the flame tube 23 and the flame chamber jacket 69 back to the flame tube side end of the housing 13. The flame chamber jacket directs the exhaust gases into a spiral Movement around.

There is a zone in the bottom area 75 of the flame chamber jacket provided without slots 71. This measure can hang any ash on the flame chamber jacket 69 stay and collect in the floor area 75. From there it is Ash can be easily removed. The flame chamber jacket 69 is a Protection for the heat exchanger 15. It protects the heat exchanger 15 largely before direct flame contact. That is why Flame chamber jacket at its front end, near that Closing member 27 or the deflecting part 39 closed and has no slots 71 through which they are not total deflected flame to the tubes 40 of the heat exchanger 15 could get.

The screw turns 77 of the heat exchanger 15 are included a straight connector 79 (Fig. 4) on both sides to a Lead 81 or a lead 83 connected. The individual heat exchanger elements 43 consist of four Windings of a tube 40 with a flat cross section and are in parallel to the lead 81 and the lead 83 connected. Bulges in the pipe wall (not shown) keep a distance between the tubes 40 of turns 77.

FIG. 5 shows a burner head 111 for liquid Fuels, with a baffle plate 113, which is not in a Wall of a combustion chamber 112 shown is mountable. On the baffle plate 113 is in the direction of flow, which by the arrow 114 is shown, a flame tube 115 with a 1: 2 diameter to length ratio arranged. Next is central on the flame tube axis 117 a lance or nozzle 119 is arranged. The fasteners for the nozzle 119 and the baffle plate 113 together form e.g. an aperture unit, as described, for example, in EPA 0 650 014 is described. The nozzle head 123 is centered in an orifice insert 125. The spray opening 121 of the nozzle 119 lies in the plane of the baffle plate 113 or Aperture insert 125. The aperture insert 125 is on the Baffle plate 113 attached and covers except for an annular Air opening 129 around nozzle head 123, opening 127 in the baffle plate 113. The annular air opening 129 takes an area of approximately 8% of the cross-sectional area of the flame tube 115 a.

The air opening 129 is also swirling Guides 131 equipped. These guide surfaces 131 are radially aligned and are opposite the flame tube axis 117 and flow direction 114 inclined so that through the Air opening 129 flowing air rotating about axis 117 is transferred. The fins or guide surfaces 131 are made made in one piece with the panel insert 125 (Fig. 7 and 8th). In their manufacture and alignment, they are up to a roughly twice the material thickness Connection 132 from the panel insert plate 134 cut out or punched and then opposite the Aperture insert plane rotated by 60 to 88 degrees. Here are on the most deformable places due to the twisting of the connections the lengths of the deforming sheet edges enlarged by round cutouts (136 in FIG. 7) by one Prevent cracking.

The flame tube 115 is with links 133 on the Baffle plate 113 attached. The links 133 are formed in one piece with the wall 139 of the flame tube 115, protrude over the baffle plate end of the flame tube 115 out and are through slots in the baffle plate 113th put through. Be upstream of the baffle plate 113 the connectors 133 twisted after plugging together, so that a firm connection between baffle plate 113 and Flame tube 115 is formed.

The connecting links 133 have a stepped, themselves tapered silhouette on. Paragraphs 137 in the stairs are on the flame tube side of the baffle plate 113 and thus define the opening width of the recirculation slot 135. Exhaust gas becomes through this recirculation slot 135 along the baffle plate 113 and the aperture insert 125 in the Flame tube 115 sucked to soot this area to prevent. A favorable opening width is around 1 mm.

In the vicinity of the baffle plate, the flame tube 115 has recirculation openings 139 through which the exhaust gas through the Vacuum, which is downstream of the baffle plate 113 due to the Air flow is created, is sucked in. In the case shown there are 18 circular recirculation openings 139 with one respective diameter of approx. 6 mm. The openings 139 can but also in a different number and / or other form.

The flame tube 115 has an inner diameter of about 80 mm and a length of about 160 mm. At the The combustion chamber 112 facing the end of the flame tube 15 is this constricted. The constriction 141 narrows the Flame outlet opening 143 opposite Flame tube cross section. The edge area 145 of the flame tube 115 is round inward to form the constriction 141 turned.

The ignition electrodes 147 are near the periphery of the Flame tube 115 with ceramic insulation pieces 149 through the baffle plate 13 and protrude with their ends 151 into the flame tube 115. The ignition point 153 is in a distance from the baffle plate 113 of about 2/5 of the length of the flame tube 115.

In Figure 6, the different zones during the Combustion is shown schematically. By making the air is blown through the air opening 129 downstream the baffle plate 113 a negative pressure in the area 161. By this vacuum is sucked in, represented by the Arrows 163 and 165. This exhaust gas forms a jacket 167 the core flow 169. The inflow along arrow 165 Exhaust gas sweeps along the surface of the baffle plate and protects them from soot deposits. Between core flow 169 and the sheath 167 arise vertebrae 171 in which the two Media air and exhaust gas are mixed.

The fuel is the shortest route through the Air flow sprayed through, shown with broken lines 172. The cone shell of the sprayed Fuel has an angle between 60 and 90 degrees. The nozzle preferably has a conical jacket characteristic 80 degrees. Gasified in an area 173 of the exhaust jacket 167 the fuel and is by vortex 175 in the exhaust jacket 167th mixed with the exhaust gas. Because upstream of the gasification zone 173 there is no gasified fuel that could burn, and on the short penetration path that the fuel must travel through airflow 169 which Fuel does not start to burn becomes practical All fuel in gas jacket 167 gasifies and arrives only in a gasified form with the air in a reaction triggering contact.

Gasified fuel is thus in vortices 171 the exhaust gas swirls with the air and burns first in the area of these vertebrae 171 cool and low in pollutants.

The flame begins in its root region 177 at the end of the first third of the flame tube 115. The flame root is annular between exhaust jacket 167 and air flow 169 embedded. The ends in the last third of the flame tube central air flow 169 in the center of the flame and cools it. The thickness of the jacket 167 is decreasing downstream because the exhaust gas / fuel vapor mixture is on this route mixed with the air. The fuel vapor is about two thirds of the flame tube length fed to the flame. The Flame thus has an annular and elongated Root area and is out of the cladding area 167 nourished.

The casing zone 167 becomes through the constriction 141 limited downstream. The gas in the jacket area 167 is at Flowing out of the flame tube 115 hindered. A swirl this favors the two media. The exiting Flame sticks to the flame tube.

In Figure 9, burner head 111 'is for gas and are different zones during the combustion of gaseous Fuel shown schematically. The burner head 111 ' corresponds essentially to the burner head 111 for liquid Fuel. Is in front of the baffle plate 113 in the direction of flow however, a perforated plate 157 at a distance from the baffle plate 113 arranged. The perforated plate 157 has an opening 158, through which the displacement body or the oil nozzle 119 pushes through. The holes are arranged around it which cause a pressure drop to kick back to prevent the flame into the feed channel 155. At the Supply duct 155 is a fuel supply and a blower arranged (both not shown).

The fact that the air / fuel mixture through the Passage 129 is blown downstream of Baffle plate 113 a negative pressure in the area 161. Through this Exhaust gas is drawn in under vacuum, represented by the arrows 163 and 165. This exhaust gas forms a jacket 167 around the Core flow 169. The exhaust gas flowing in along arrow 165 strokes the surface of the baffle plate and protects them from depositing soot. Between the core flow 169 and the Sheath 167 arise vertebrae 171, in which the two media Air / fuel and exhaust gas are mixed. More gaseous Fuel is therefore combined with the air in vortices 171 swirls with the exhaust gas and only burns in the area of this Vortex 171 cool and low in pollutants.

The flame begins in its root area 177 in the first Third of the flame tube 115. The flame root is ring-shaped between exhaust jacket 167 and air / fuel flow 169 embedded. The central stream 169 ends in the center of the Flame and cool it. The thickness of the sheath is 167 decreasing downstream because the exhaust gas is on this System mixed with the air / fuel mixture. The Fuel burns quietly and is low in pollutants.

The gas burner works practically regardless of the shape of the furnace. It is particularly suitable for compact firing systems with short firing rooms. The burner is not only suitable for burning gas. By replacing the displacer 119 with a fuel nozzle for liquid fuel with a conical jacket characteristic, it is particularly suitable for the combustion of heating oil which is extra light, eco-oil or kerosene. The burner achieves exhaust gas values for NO _x below 60 mg / kW with liquid fuels.

Claims (20)

1. Boiler comprising a burner and a housing surrounding the boiler compartment, a jacket like heat exchanger dividing the boiler compartment into a combustion chamber (17, 112) and an exhaust chamber (19), whereby said heat exchanger comprises passages (41) distributed across its surface for hot exhaust gases, and a burner head (111, 111') positioned in the combustion chamber, the burner head comprising a fire tube (23, 115) with an axial flame opening (37, 143), and a flame deflector piece (39) positioned at a distance from the flame opening (37, 143), characterised in that the flame deflector piece (39) is shaped in such a manner that the flame (25) is deflected to the area in between the fire tube (23, 115) and the heat exchanger (15), and that the passages (41) for hot exhaust gases are distributed across the whole length of the combustion chamber (17).
2. Boiler of claim 1, characterised in that the heat exchanger (15) comprises a blocking plate (27) located at or near at least one end of the heat exchanger, and wherein the blocking plate (27) at its side facing away from the boiler compartment separates an exhaust discharge chamber (29) from the boiler compartment, the exhaust discharge chamber can be connected to a flue.
3. Boiler of claim 1 or 2, characterised in that the heat exchanger (15) comprises a blocking plate (27) located at or near at least one end of the heat exchanger, the blocking plate (27) separating a recirculation chamber (33) from the boiler compartment.
4. Boiler of one of the claims 2 or 3, characterised in that one of the chambers (29, 33) separated by a blocking plate (27, 27') is jacketed by the heat exchanger (15).
5. Boiler of one of the claims 2 through 4, characterised in that the blocking plate (27) comprises a domed surface pointing towards the exhaust discharge chamber (29).
6. Boiler of one of the claims 1 through 5, characterised in that the flame deflection piece (39) comprises a flame separator (47), which is positioned along the flame centerline (45, 117) and facing the flame (25), and a ring-shaped deflector dish (49), which surrounds the flame separator.
7. Boiler of one of the claims 2 through 6, characterised in that the flame deflector piece (39) forms a blocking plate (27).
8. Boiler of one of the claims 1 through 7, characterised in that the heat exchanger (15) consists of pipes (40) positioned adjacent to one another with clearance (41) between the pipes; whereby said pipes are positioned to enxlose the combustion chamber (17, 112) and are connected to a supply line (81) and a return line (83).
9. Boiler of one of the claims 1 through 8, characterised in that the heat exchanger pipes (40) are helically wound.
10. Boiler of one of the claims 1 through 9, characterised in that the outer shell of the heat exchanger (15) is assembled from a plurality of heat exchanger units (43)
11. Boiler of claim 10, characterised in that the heat exchanger units (43) are connected in parallel to the supply line (81) and the return line (83).
12. Boiler of one of the claims 1 through 11, characterised in that the burner is equipped to burn oil and/ or gas, and for exhaust gas recirculation; whereby the burner can be switched to burn either gas or oil, if needed.
13. Boiler of one of the claims 1 through 12, characterised in that the burner head is equipped with a centrally mounted fuel injector, capable of producing a conical shroud spray pattern, a baffle plate with an air vent, a fire tube positioned adjacent and downstream of the baffle plate, which fire tube comprises openings near the baffle plate to allow exhaust gas to enter a sub-atmospheric pressure region behind and downstream of the baffle plate; and that the spray opening (121) of the fuel injector (67, 123) is positioned approximately in the plane of the baffle plate (61, 113), which generates the sub-atmospheric pressure; whereby the baffle plate (61, 113) comprises one single opening, forming an air inlet vent (129), which is annularly and concentrically located, with respect to the fuel injector (67, 123),.
14. Boiler of one of the claims 1 through 13 with a blower and a fuel supply for gaseous fuel, characterised in that the fuel supply for gaseous fuel is positioned in the supply passage (155) at such a distance from the baffle plate (61, 113), that a practically homogenous mixing of fuel and air is ensured in front of the baffle plate (61, 113), and that the baffle plate (61, 113) closes off the supply passage (155) with the exception of a central vent (129).
15. Boiler of one of the claims 12 through 14, characterised in that the air vent (129) of the baffle plate (61, 113) comprises spin-generating guide plates (131).
16. Boiler of one of the claims 1 through 15, characterised in that a cylindrical combustion chamber jacket (69) with passages (71) for hot exhaust gas is located in the combustion chamber (17) in between the fire tube (23, 115) and deflected flame (25), respectively, and the heat exchanger (15).
17. Boiler of claim 16, characterised in that the passages (71) are shaped such that the exhaust gases exit the combustion chamber jacket (69) about tangentially; whereby the combustion chamber jacket (69) may be closed off near the blocking plate (27) or the flame deflector piece (39), respectively.
18. Boiler of one of the claims 16 or 17, characterised in that the cylindrical combustion chamber jacket is closed off in a bottom area (75).
19. Boiler of one of the claims 1 through 18, characterised in that the blower is positioned adjacent to the housing (13) and a supply passage (155) is provided from the blower to the end face of the housing (13) and onto the fire pipe (23, 115).
20. Boiler of one of the claims 1 through 19, characterised in that one end face of the housing (13) is closed off with a cover (57) onto which the burner head (111, 111') is mounted.

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