WO1982000331A1

WO1982000331A1 - Hot gas generator

Info

Publication number: WO1982000331A1
Application number: PCT/DE1981/000110
Authority: WO
Inventors: D Popp
Original assignee: D Popp
Priority date: 1980-07-12
Filing date: 1981-07-11
Publication date: 1982-02-04
Also published as: EP0044063A1; DE3026516A1

Abstract

A combustion chamber (1), substantially conical, is provided at its wider end with a combustion device (2) which opens coaxially therein, and at its opposite end with an air supply device (11, 12). The area of the chamber (1) close to the wider end has a lateral outlet (18) for hot gases and the combustion device (2) has an oil or gas burner (3) and, arranged around those, an annular nozzle (4) intended for the supply of pulverulent fuel, particularly wood powders containing resins, as well as a nozzle for the supply of primary air (5). The lower end of the combustion chamber (1) has a discharge opening for the ashes which opens into a combustion chamber (7) with a combustion surface (8) and which is provided with a supply device (9) for a solid fuel. The combustion chamber (1) may be provided with a jacket, and in this case an air screen flows between the double wall (22). The inner wall (33) of the combustion chamber (1) may be formed by pipes provided with ribs wherein the pipes are circulated by a heat conveying agent.

Description

Name: hot gas generator

Description: The invention relates to a hot gas generator with an approximately conical combustion chamber which is provided at the wide cone end with a burner device opening axially into the combustion chamber and at the opposite end with an air supply device and which has a lateral hot gas outlet in the region of the wide end.

Combustion chambers of the type described at the outset are for engines, i.e. So basically known in small dimensions and for operation with liquid or gaseous fuels.

In the industrial field, in particular for drying purposes or the provision of process heat, however, combustion chambers with considerably larger dimensions are required. In addition, there is often a need for

Heat generation also to use existing dust-like fuels, especially in manufacturing processes in which, for example in the woodworking industry, combustible dusts are produced.

The invention has for its object to provide a hot gas generator, the burner device with dusty fuels, especially flame-retardant dusty substances can be operated.

This object is achieved according to the invention in that the burner device has an oil or gas-loaded burner and an annularly arranged nozzle for the supply of dusty fuels, in particular synthetic resin-containing wood dust, and a nozzle for the supply of primary air. The hot gas generator according to the invention has the advantage that the

Most of the combustion air is conducted in countercurrent to the fuel, so that there are long burnout paths and an intensive mixing of the dusty fuel supplied in the flame area. Since the synthetic resin component, especially with dusts containing phenolic resin, only burns properly in a direct flame, this ensures almost complete burnout. The intended oil or gas-loaded burner only serves as a support or pilot burner.

In a preferred embodiment of the invention it is provided that the combustion chamber is arranged upright, the burner device is arranged facing downward at the upper end of the combustion chamber and the lower end of the combustion chamber has an ash outlet opening which opens into a combustion chamber with a burnout surface, which with an additional air supply and is provided with a supply device for lumpy fuel, in particular wood waste, and with a pilot burner in the mouth area of the material supply device. This configuration has the advantage that, in addition to the dust-like waste products, lumpy, combustible waste products, for example in the woodworking industry, wood waste, bark or the like can also be used for hot gas production. Since an ember bed is formed on the burn-out surface by the additional fuel supply, any ash content is removed The unburnt particles in the combustion chamber that have entered the combustion chamber are completely burned on the burnout surface. The arrangement also has the advantage that the solid fuel introduced into the combustion chamber in the form of a dust can have a relatively high proportion of coarse grain, since these coarse-grained components which do not completely burn out in the combustion chamber can completely burn out in the combustion chamber. The pilot burner for the combustion chamber is only switched on until the lining of the combustion chamber is heated up to such an extent that the combustion of the particulate fuel supplied takes place automatically. The hot exhaust gases in the combustion chamber reach the combustion chamber through the ash outlet opening, where they are further heated. The hot gases drawn off from the combustion chamber at the upper end are then completely available for the intended use, for example for carrying out a drying process.

In an expedient embodiment of the invention, it is provided that the burnout surface is designed as a feed grate with a grate covering that is largely free of diarrhea. This ensures that a relatively dense ember bed forms on the burnout surface, which hinders the diarrhea of dust-like particles.

In a further embodiment of the invention it is provided that the combustion chamber is double-walled and that the free space between the inner wall and outer wall in the area of the burner device is provided with at least one inlet opening for cold air and at the lower end with at least one outlet opening for the hot air and that the hot air outlet opening is connected to the lower air supply device of the combustion chamber. This configuration has the advantage that the walls of the combustion chamber are cooled and that thus heated air can be introduced at the lower end as heated combustion air.

In an expedient embodiment of the invention, it is provided that the lower air supply device is formed by an annular channel which is placed around the lower end of the combustion chamber and which is provided with at least one outside air inlet opening and a plurality of air passage openings opening tangentially into the combustion chamber. The tangential introduction of the combustion air results in a defined countercurrent flow of air and fuel, which at the same time ensures that the combustion chamber wall is shielded from the flame by an air curtain. The tangential introduction of the main combustion air also has the advantage that the hot exhaust gases entering through the ash outlet opening from the combustion chamber are drawn into the generated air swirls, so that stable flow conditions result in the combustion chamber and the best possible combustion of the dust-like fuel is ensured. The supplied combustion air and the hot exhaust gases emerging from the combustion chamber are directed upwards in a swirl flow along the inner wall of the combustion chamber. In this case, fuel particles which are not completely burned out are again torn upwards and, as a result of the toroidal secondary flow which forms in the upper part of the combustion chamber, are returned to the flame, where they can burn out completely. It is expedient if, according to the invention, the air passage openings are provided with adjusting flaps. This enables an optimal setting of the swirl flow.

In a further embodiment of the invention it is provided that the ring channel has a cross-section which decreases in the flow direction and is closed at one end with respect to the air inlet opening, which is coaxial around the ring channel, a second ring channel is arranged, with an air outlet located laterally next to the air inlet of the first ring channel and that the second ring channel is provided with a plurality of air passage openings which open into the space between the inner and outer walls of the combustion chamber. Since the outer wall of the second ring channel runs coaxially with the inner wall of the first ring channel, a flow cross section inevitably results for the second ring channel, so that the flow cross-section widens towards the air outlet opening, so that the cooling air led through the space between the outer wall and the inner wall is extracted as well Supply of the main combustion air results in a structurally simple component. Since the cross-section of the first ring channel decreases in accordance with the decrease in the amount of air to be introduced into the combustion chamber, on the other hand the cross-section of the second ring channel increases in accordance with the increase in the amount of air drawn from the intermediate space, an air outlet which is uniformly distributed over the circumference becomes both for the first ring channel as well as for the second ring channel. The air outlet of the two th ring channel can now be connected to the suction side and the air inlet of the first ring channel to the pressure side of a hot gas fan, so that the cooling air drawn through the space between the inner and outer walls of the combustion chamber can be introduced directly into the combustion chamber as heated combustion air .

In a preferred embodiment of the invention, it is further provided that the inner wall of the combustion chamber is formed by tube-web tubes, which run vertically and each open into a ring line at the top and bottom, the upper ring line with the inlet and the lower ring line with are connected to the return flow of a heat consumer through which a heat transfer medium flows. This design not only has the advantage that in addition to the hot gas generation is also possible heating a liquid and / or vaporous heat transfer medium. The heat consumer (s) can be downstream heat exchangers in which air, water or, in the case of the woodworking industry, presses can be heated. The design is also advantageous when using phenolic resin-containing wood dust. The more intensive cooling of the combustion chamber walls which is possible in this embodiment makes it possible to maintain surface temperatures which are below the melting point of the caustic soda obtained when phenolic resin is burned. It is particularly advantageous here if, in the area of the hot gas outlet opening of the combustion chamber, the tubes forming the inner walls are made web-free and run at a distance from one another. The pipes here form a kind of grille through which the hot gases generated in the combustion chamber must flow. Airborne dust, unburned fuel particles can accumulate here and at the same time the slight cooling of the gas stream which begins when this grille flows through when phenolic resin dust is used leads to extinguishing a part of the possibly still glowing phenolic resin dust particles. Aggressive volatile constituents of the burned synthetic resin components contained in the exhaust gases can also precipitate on this grille as a result of the cooling effect. Appropriate cleaning openings in the ceiling area of the combustion chamber allow the pipes and the entire inner wall of the combustion chamber to be cleaned from time to time.

In a preferred further embodiment of the invention it is provided that a hot gas duct is provided in the upper region of the combustion chamber, which extends over part of the inner wall of the combustion chamber and the wall of which is formed from tube-web tubes which are connected to the other tube-web tubes. Tubes of the inner wall are connected and that the channel with one end against the rotation of the gas flow is open to the combustion chamber interior and ends at the other end in a lockable gas exhaust. The se arrangement has the advantage that the combustion chamber can also be operated in the partial load range if no Heißga se are required for a downstream drying process, however, corresponding amounts of heat must be made available via the liquid or vaporous heat transfer medium. In this case, the hot gas outlet of the combustion chamber is shut off, so that the hot exhaust gases now produced with reduced fuel supply can be drawn off through the hot gas duct guided along the inner wall in the upper region, and their heat content largely rests on the duct walls formed from tube-web tubes submit. The cooled exhaust gases can then be blown off into the open via a dedusting device.

In an advantageous further embodiment of the invention it is provided that at the hot gas outlet opening of the combustion chamber a trained in the manner of a Venturi tube

Part of a hot gas exhaust line is connected and that in the area of the narrowest cross-section there is an annular duct encompassing this part, which is connected to openings and at least one air inlet preferably opening tangentially into the exhaust line additionally to supply air, both in order to be able to regulate temperature peaks and to be able to regulate fluctuations in the amount of hot gas occurring in the downstream consumer. Correspondingly, cold air or hot air produced by cooling the combustion chamber wall can be introduced here. This hot air can either be directly available in an air-cooled combustion chamber or in a liquid-cooled one

Combustion chamber via a heat exchanger through the heat transfer medium the cooling of the combustion chamber inner wall are heated.

The invention is explained using schematic drawings of exemplary embodiments. Show it:

Fig. 1 shows a vertical section of a hot gas generator

Fig. 2 on a larger scale a horizontal section along the line II - II in Fig. 1 Fig. 3 shows another embodiment of the hot gas generator in the vertical section

4 shows a horizontal section along line IV-IV in FIG. 3

5 shows a section on a larger scale through the inner wall formed from tube-web tubes of the embodiment according to FIG. 3

Fig. 6 shows an embodiment with additional air cooling of the combustion chamber wall

7 shows an annular channel for the embodiment according to FIG. 6

8a, b a deflecting surface for the hot gas outlet

The embodiment of the hot gas generator shown in a vertical section in FIG. 1 has a vertically oriented, essentially conical combustion chamber 1. In this combustion chamber, a burner device 2 protrudes from above into the enlarged area, which has an oil or gas-loaded burner 3 of conventional design, to which an annular nozzle 4 for the supply of a dusty fuel and a further annular nozzle 5 for the supply of primary combustion air are assigned.

On the side opposite the burner device, the combustion chamber 1 has an ash outlet opening 6 which leads into a combustion chamber 7 with a step grate trained, inclined burnout surface 8 opens. At the upper end of the combustion chamber 7, a supply opening 9 for a lumpy fuel, such as wood waste or bark is provided, which is completed in the usual way by means of a double flap lock, not shown, against the outside air. In the area of the upper end of the burnout surface 8, a pilot burner 10 is arranged through which the combustion of the fuel applied to the burnout surface 8 can be initiated.

The main combustion air is supplied via an annular channel 11 which is placed around the lower end of the combustion chamber and which is provided with a plurality of air passage openings 12 opening tangentially into the combustion chamber. The preferably heated combustion air is supplied via an external air inlet opening 13, which is connected to a corresponding supply duct 14, via which the majority of the combustion air is supplied by an air heater. From the supply channel 14 branches off a mixed air channel 15, which is guided to a further ring channel 16, which is laid around the line 18 to the hot gas exhaust. The annular channel 16 is also provided with a series of air passage openings 19 which open tangentially into the hot gas exhaust line 18. In the area of the hot gas outlet opening 17, the hot gas discharge line 18 is designed in the manner of a Venturi tube, so that the annular channel 16 is arranged in the area of the narrowest cross section of this part of the hot gas discharge line 18.

The combustion chamber 1 according to this embodiment is double-walled, so that a free space 22 remains between the inner wall, which is formed, for example, by a refractory brick lining, and the outer wall 21, which consists, for example, of insulating material. The gap 22 is in the area of the upper end the combustion chamber with an inlet opening 23 for cold air and in the region of the lower end with an outlet opening 24 for the hot air. With the help of the cold air led through the intermediate space, the inner wall 20 of the combustion chamber can thus be constantly cooled, the cold air being introduced into the area with the highest temperature, so that sufficient protection of the lining is achieved.

The hot air obtained during cooling of the combustion chamber wall can now advantageously be returned to the combustion chamber as heated combustion air. This is expediently done via an annular channel 11 ', as shown in horizontal section in FIG. 2. In this preferred embodiment, a ring channel 11b serving as air supply to the combustion chamber and having a cross section decreasing in the flow direction of the hot air (arrow 25) is coaxially wrapped around an annular channel 11b serving as an air vent for the space 22. This ring channel has an increasing cross section in the direction of flow of the introduced air (arrow 26). On its upper side, the annular duct 11b is provided with a multiplicity of air passage openings 27 which open into the intermediate space 22 of the combustion chamber 1. The air passage openings 12 of the annular duct 11a opening into the combustion chamber are each provided with a control flap 28 in the exemplary embodiment shown, which can be adjusted by means of a central actuator of a conventional type (not shown).

The air inlet opening 13 of the ring duct 11a ′ and the air outlet opening 29 are connected to a hot gas fan 30 via corresponding pipelines. Here, the air outlet 29 with the suction side and the air inlet 13 with the pressure side of the hot gas fan

connected. A branch line 15 can also be connected correspondingly to FIG. 1 to the pressure-side line, which corresponds to the pipeline 14 in FIG. 1. The pipeline 14 and also the pipeline 15 can be pushed off accordingly by corresponding pushers 31, 32.

FIG. 3 shows another embodiment of the hot gas generator according to the invention. The shape and the process engineering structure correspond to the embodiment according to FIG. 1. The burner device 2 according to FIG. 1 is indicated by an arrow.

In contrast to the embodiment according to FIG. 1, the inner wall of the combustion chamber 1 in FIG. 3 is formed by so-called tube-web tubes 33, each with its lower end and with its upper end in a ring line 34 or 35 flow out. A liquid or vaporous heat transfer medium, which is led from the bottom upwards via the ring lines and the tube-web tubes, is preferably circulated via a heat consumer, not shown, the lower ring line 34 with the return 36 and the upper ring line 35 with the inlet 37 of the heat consumer are connected. The lining by means of tube-web tubes represents a completely closed gas-tight lining because, as the cut according to Fig. 5 shows the individual tubes 38, which may have a round or oval cross section, are firmly connected to one another by intermediate webs 39, so that a closed wall formed from a plurality of tubes running side by side is formed. Only in the area of the gas passage opening are the corresponding webs omitted, so that in this area a type of grille for any solid particles is formed by the tubes 38. In the illustrated embodiment according to

3, the inner wall 33 formed from tube-web tubes is provided on its outside with a heat-insulating outer layer 40. The annular duct 11 with its air passage openings 12 is connected to a blower, not shown, through which heated combustion air can be supplied. The combustion air can be heated, for example, in such a way that the heat transfer medium passed through the tube-web tubes is passed through a heat exchanger, with the aid of which the combustion air is heated. Due to the heat given off by the heat consumer, there may also be several heat consumers, the inner wall of the combustion chamber 1 is cooled to the desired extent.

Since the inner wall 33 formed from tube-web tubes with the ring lines 34 and 35 is a self-contained component, as in the embodiment. 1, a corresponding space is provided between the inner wall 33 and the insulating outer wall 40, through which air is then passed with the aid of a blower, which directly as heated combustion air via the ring channel 11, which in this case corresponds to the representation according to FIG 2 can be designed to be introduced into the combustion chamber as combustion air. Depending on the dimensioning of the blower output and the required air volume, a separate heat exchanger for heating the combustion air can be dispensed with, since the required air volumes can be heated to the desired temperature through the space between the inner wall 33 and the insulating outer wall 40.

Since in the air flow explained in connection with FIG. 2 through the space, the heated air ge 6 and 7, a modified embodiment for the formation of the space between the inner wall and the outer wall is explained, which allows the cold air to be passed under pressure through the space. In Fig. 6 the combustion chamber wall is shown partly in section, partly in the form of a development. Fig. 7 shows the corresponding design of the associated lower ring channel 11th

In the embodiment shown in FIG. 6, the intermediate space 22 is divided between an inner wall 33 formed, for example, of tube web tubes and an insulating outer wall 40 by vertically extending webs into a plurality of sub-channels 41, 42 that run alongside one another. These webs are designed so that every second web is somewhat shorter, so that an overflow opening 43 remains between the channels 41 and 42 at the top. The lower end of each channel 41 is accordingly connected to an air passage opening 44 of the outer ring channel 45, while the lower end of the adjacent channel 42 is connected to an air passage opening 46 of the inner ring channel 47. If cold air is now pressed into the ring channel under pressure via the air inlet opening 48 connected to the outer ring channel 45, it flows through the air passage openings 44 and the associated channel 41 in the intermediate space 22 initially upwards and then flows in via the air transition opening 43 in the adjacent channel 42 below and can then enter the inner annular channel 47 via the air passage opening 46 and from there into the combustion chamber via the air passage openings 12. 6 from the sectional view, it is useful if the outside of the tube-web Pipes formed inner wall 33 is provided with projections 54 in the form of pins, warts, webs or the like, through which the heat transfer area is increased, so that the heat transfer from the inner wall 33 to the air passed through the channels 41 and 42 is increased. As a result, the effectiveness of the cooling air duct for cooling the combustion chamber, which also serves to heat the air, is improved.

Since the design according to FIG. 3 with an inner wall made of tube-web tubes can also be used for hot water or steam generation in addition to hot gas generation due to the possible use of water as a heat carrier, for some applications a possibility must also be created, the combustion chamber to operate even when there is no need for hot gas, but hot water or steam must be made available. Since here the burner device 2 only has to be operated with reduced output, but there is nevertheless a desire to burn out the dust-like fuel, in particular dust-like combustible waste even with reduced burner output, the embodiment according to FIG. 3 shows a device which provides such pure hot water - or steam operation enabled. For this purpose, a parallel tube 49 is provided in the manner shown in the flame zone in the upper region of the combustion chamber of each tube belonging to the inner wall 33. These adjacent parallel pipes 49 are in turn connected by webs to form a dense wall, so that a channel is formed between the pipe sections 50 running in this area on the wall side and the parallel pipes 49, as can be seen from the sectional view according to FIG. 4. This channel 50 ′ extends over part of the circumference of the combustion chamber in this area and only leaves the area associated with the gas passage opening 17 free. An end to this The channel is open to the combustion chamber interior, while the other end of the channel is closed off from the combustion chamber interior and is connected to an exhaust gas fireplace via a filter device, not shown. If applicable Additional parallel tubes 51 can be arranged in the channel, but are arranged at a greater distance from one another, by means of which the heat transfer area in the region of the channel 50 'is increased.

If there is now no need for hot gases for any downstream driers or the like, the hot gas outlet opening 17 is shut off and the outlet opening 52 of the channel 50 'to the exhaust gas fireplace is opened via a slide (not shown). To overcome the flow resistances, in particular the dedusting system, it is expedient if an exhaust gas fan working in the suction draft is arranged behind the dedusting system. Since the hot exhaust gases generated during combustion can no longer exit through the blocked hot gas outlet opening 17, they flow through the channel 50 'and are then drawn off via the filter system and the exhaust gas chimney. In this way, they give off their heat to the additional tubes 51 and to the parallel tubes 49 and 50, which limit the channel 50 ".

For a better understanding it should be mentioned that only the tubes of the inner wall 33 lying in the sectional plane are shown in the illustration according to FIG. 3. Of the large number of tubes forming the inner wall, only the tube that is located at the closed end 53 of the channel 50 'is shown.

The channel 50 'is accessible in the usual way for cleaning purposes via cleaning openings 54 in the ceiling area of the combustion chamber, as is the one that forms the grille Part of the tubes in the area of the hot gas outlet opening 17.

The embodiment of an annular duct shown in FIG. 7 for the lower air supply to the combustion chamber also offers the possibility of introducing air into the inner annular duct 47 via a corresponding opening and a regulating flap 55 in addition to the quantities of hot air introduced through the air passage openings 46. This provides another control option for the combustion chamber.

The arrangement of the channels shown in FIG. 6 in the space between the outer wall and the inner wall represents a preferred embodiment which offers the least flow resistance with large amounts of air to be heated. Deviating from this, the channels can also run differently, for example helically.

In a preferred embodiment of the invention it is further provided that the tubes 50 in the region of the hot gas outlet opening 17 of the combustion chamber 1 are each provided with inwardly directed deflection surfaces 57. This not only results in better guidance of the rotating gas flow in the combustion chamber along the spaced-apart tubes 50 in the region of the hot gas outlet opening, but also the retention of solid particles in the combustion chamber itself is further improved. The gas quantities flowing out via the hot gas outlet opening 17 must flow around the free edges of the deflecting surfaces with a change of direction when they pass from the rotary flow of the combustion chamber, so that solid particles contained in the gas flow are held in the rotary flow and cannot enter the hot gas exhaust line 18 via the hot gas outlet. Especially It is advantageous if the deflecting surfaces 57 are oriented obliquely inward in approximately the same direction as the rotation of the gas flow. As a result, the deflecting effect of the deflecting surfaces 57 is further increased, so that the separating effect is increased in the region of the free edges of the deflecting surfaces. At the same time, this ensures that at least a portion of the solid particles of the rotary flow that reach the surface of the deflecting surfaces facing the combustion chamber are then taken up again and carried along further. The basic arrangement of such deflection surfaces is shown in FIG. 4.

In an expedient embodiment of the invention, it is provided here that the deflection surfaces 57 are adjustably connected to the respective tube 50 with respect to their alignment in order to be able to make an optimal setting.

It is also expedient if each deflection surface is formed from a plurality of partial surfaces arranged one above the other and that each partial surface is fixed to the respective tube 50 with a wedge connection. This makes it possible to prevent thermal stresses even with a large height of the hot gas outlet opening with a correspondingly long length of the deflecting surfaces, since corresponding expansion joints can be provided between the individual partial surfaces. The arrangement of a wedge connection makes it easy to replace the steering surfaces, since even a scaled-up wedge can be knocked out without difficulty. A component for such a partial surface with a wedge connection is shown in plan and side view in FIGS. 8 a, b. The embodiment shown also shows a possible design for the shape of the deflection surface. In this embodiment, the flow edge 58 protrudes freely into the combustion chamber with respect to the rotational flow (arrow 59) additionally angled so that the deflection for the gas flow when entering the hot gas outlet opening 17 is further reinforced.

The component is produced, for example, as a cast part and has two eyelets 60 which encompass the tube 50 in question, into which a wedge 61 is driven, by means of which the deflection surface 57 is fixed on the tube 50. Because the openings of the two eyelets 60 run obliquely with respect to the tube axis 62, the wedge is also secured against falling out.

Claims

Expectations:

1.Hot gas generator with an approximately conical combustion chamber, which is provided at the wide cone end with a burner device opening axially into the combustion chamber and at the opposite end with an air supply device and which has a lateral hot gas outlet in the region of the wide end, characterized in that the burner device ( 2) an oil or gas pressurized burner (3) and a ring-shaped nozzle (4) for the supply of dusty fuel, in particular resin-containing wood dust, and a nozzle (5) for the supply of primary air.

2. Hot gas generator according to claim 1, characterized geken nz eic hn et that the combustion chamber (1) is arranged upright and the burner device (2) is arranged facing downwards at the upper end of the combustion chamber (1) and the lower end of the combustion chamber has an ash outlet opening (6 ) has, which opens into a combustion chamber (7) with burnout surface (8), with an additional air supply and with a supply device (9) for lumpy fuel, ins special wood waste, and is provided with a pilot burner (10) in the mouth area of the feed device for the lumpy fuel.

3. Hot gas generator according to claim 2, characterized in that the burnout surface (8) is designed as a feed grate with a largely diarrhea-free grate covering.

4. Hot gas generator according to one of claims to 3, characterized in that the combustion chamber (1) is double-walled and that the free space (22) between the inner wall (20; 33) and outer wall (21; 40) in the area of the burner device (2 ) is provided with at least one inlet opening (23) for fresh air and at the lower end with at least one outlet opening (27) for the hot air and that the hot air outlet opening (27) is connected to the lower air supply device of the combustion chamber (1).

5. Hot gas generator according to one of claims 1 to 4, characterized in that the lower air supply device is formed by an outside around the lower end of the combustion chamber ring channel (11) having at least one external air inlet opening (13) and a plurality tangentially into the combustion chamber (1) opening air passage openings (12) is provided.

6. Hot gas generator according to claim 5, characterized in that the air passage openings (12) are provided with flaps (28).

7. Hot gas generator according to one of claims 4, 5 or 6, characterized in that the annular channel (11a) has a decreasing cross in the flow direction (25) has a cut and is closed at one end opposite the air inlet opening (13) that a second ring channel (11b) is arranged coaxially around the ring channel (11a), with an air outlet (laterally next to the air inlet (13) of the first ring channel (11a)) 29) and that the second ring channel (11b) is provided with a plurality of air passage openings (27) which open into the space (22) between the inner wall (20; 33) and outer wall (21; 40) of the combustion chamber (1).

8. Hot gas generator according to one of claims 1 to 7, characterized in that the inner wall (33) of the combustion chamber (1) is formed by tube-web tubes which run vertically and in each case above and below in a ring line (34, 35) mouth, the upper

Ring line (35) are connected to the inlet (37) and the lower ring line (34) to the return line (36) of a heat consumer through which a heat transfer medium flows.

9. A hot gas generator according to claim 8, characterized in that the opening of the combustion chamber (1) in the region of the hot gas outlet opening (17) is designed to be web-free and that the tubes forming the inner wall (33) are spaced apart.

10. Hot gas generator according to claim 8 or 9, characterized in that a hot gas channel (50 ') is provided in the upper region of the combustion chamber (1), which extends over part of the inner wall of the combustion chamber (33) and the wall of which is made of a tube web -Pipes (49) is formed, which are connected to the other tube-web tubes of the inner wall (33) and that the channel (50 ') is open at one end against the rotation of the gas flow to the combustion chamber interior and at the other end (52) opens into a lockable gas vent.

11. Hot gas generator according to one of claims 1 to 10, characterized in that to the hot gas outlet opening (17) of the combustion chamber (1) is designed in the manner of a Venturi tube part of a hot gas exhaust line (18) is connected and that one the area of the narrowest cross section This part comprising an annular duct (16) is provided, which is connected to air passage openings (19) which preferably lead tangentially into the exhaust line (18) and at least one air inlet.

12. Hot gas generator according to claim 11, characterized in that the air inlet of the ring channel (16) to the hot gas discharge line (18) and / or the air inlet of the ring channel (11) at the lower end of the combustion chamber (1) is connected to an air heating device .

13. Hot gas generator according to claim 12, characterized in that the air heating device is acted upon by at least part of the heat carrier flowing through the tube-web tubes of the combustion chamber (1).

14. Hot gas generator according to one of claims 1 to 13, characterized in that the combustion chamber (1) is double-walled and that the free space (22) between the inner wall (20; 33) and outer wall (21; 40) in channels (41, 42) is divided so that two adjacent channels (41, 42) are connected in the upper area by an air transfer opening (43), that two separate ring channels (45, 47) are provided at the lower end of the combustion chamber, that every second vertical channel (41 ) are connected via an air passage opening (44) to one ring channel (45) and the other vertical channels are connected to the second ring channel (47) via air passage openings (46) such that the second ring channel (47) opens into the combustion chamber (1) Air passage openings (12) is provided and that at least the first ring channel (45) is provided with a fresh air supply opening (48).

15. Hot gas generator according to claim 14, characterized in that the channels (41, 42) run essentially vertically.

16. Hot gas generator according to one of claims 9 to 15, characterized in that the tubes (50) in the region of the hot gas outlet opening (17) of the combustion chamber (1) are each provided with inwardly directed deflection surfaces (57).

17. Hot gas generator according to claim 16, characterized in that the deflecting surfaces (57) are oriented approximately in the same direction as the direction of rotation (59) of the gas streams obliquely inwards.

18. Hot gas generator according to claim 16 or 17, characterized in that the deflection surfaces (57) are adjustably connected with respect to their alignment with the respective tube (50).

19. Hot gas generator according to one of claims 16 to 18, characterized in that each deflecting surface (57) is formed from several partial surfaces and that the partial surfaces are each fixed to the respective tube (50) with a wedge connection (60, 61).

20. Hot gas generator according to one of claims 10 to 19, characterized in that the 'opening into the combustion chamber (1) (63) of the hot gas duct (50') is covered by a spaced deflection surface (64).