AT527229B1 - hot gas generator - Google Patents

Abstract

A hot gas generator (1) with a longitudinal axis (L) comprises a burner (2), a combustion chamber (3) which is surrounded by an axially running, fire-resistant lined flame tube (4), an axially running, essentially tubular generator casing (8) which surrounds the flame tube (4) at least in sections, wherein a swirl channel (9) enclosing the flame tube (4) is formed between the generator casing (8) and the flame tube (4), and a supply line (14) for supplying a gas to be heated, which opens into a supply section (16) of the swirl channel (9). The supply section (16) extends over the entire width (Z) of the supply line (14) running in the axial direction. The generator casing (8) extends in the supply section (16) in a spiral shape around the longitudinal axis (L), so that the swirl channel (9) in the supply section (16) tapers around the flame tube (4) starting from the supply line (14).

Description

Description

[0001] The invention relates to a hot gas generator with a longitudinal axis, comprising

* a burner for generating flue gas,

* a combustion chamber surrounded by an axially extending, refractory-lined flame tube which is closed at one burner end where the burner enters the combustion chamber and open at one outlet end,

* an axially extending, essentially tubular generator casing, which extends from a supply end arranged in the direction of the burner end to a connection end protruding beyond the outlet end and opening into a connection opening, and thereby encases the flame tube at least in sections, wherein a swirl channel extending from the supply end towards the connection end and enclosing the flame tube is formed between the generator casing and the flame tube, and

* a supply line for supplying a gas or gas mixture to be heated or to be heated, which opens into a supply section of the swirl channel and whose line cross-section is aligned transversely, in particular orthogonally, to a tube cross-section of the flame tube.

[0002] Many technical processes require a warmed or heated gas or gas mixture. As is well known, hot gas generators are used for this purpose, in which hot flue gases from a combustion chamber are mixed with the gas or gas mixture to be warmed or heated in order to generate the so-called hot gas. The gas or gas mixture to be warmed or heated can be, for example, air, another gas or gas mixture, an exhaust gas or a flue gas.

[0003] Possible applications for which a hot gas generator is required include:

the provision of “under-air” for drying purposes, such as for sewage sludge drying (in fluidized bed ovens);

- the provision of hot gas for the pre-drying of ores prior to roasting the ores;

- reheating of exhaust gases before feeding them to a DeNOx system, e.g. after an RTO, a wet scrubber, a steam generator or a filter;

- the heating of flue gases after a steam boiler;

[0004] Typically, a hot gas generator has a combustion chamber in which a fuel (gas or liquid fuel) is burned via a burner, producing hot flue gas. The hot flue gas flows out of the combustion chamber at an outlet end. The combustion chamber is enclosed by a generator casing which extends beyond the outlet end and opens into a connection opening. The gas or gas mixture to be warmed or heated is introduced into the interior of the generator casing via a supply line which opens into the generator casing in the area of the combustion chamber. The gas or gas mixture to be warmed or heated flows past the combustion chamber, mixes with the hot flue gas in the area of the outlet end and flows mixed with the flue gas as hot gas from the connection opening of the hot gas generator into further lines or into devices connected to them (e.g. consumers).

[0005] In order to produce a hot gas that is as homogeneous as possible, static mixing elements such as guide plates or diversions are generally provided in the generator casing. These ensure that the mixture of gas to be heated or gas mixture and hot gas that hits them is swirled and thus ensure better mixing in the hot gas. Depending on the required degree of homogenization, further static mixing elements can be provided in lines connected to the hot gas generator that lead to other devices.

[0006] Hot gas generators of this type are known, for example, from US 1,629,921 A, GB 1,034,213 A and EP 0 004 395 A1. Another hot gas generator in which the supply

However, the line flows into the generator casing in the direction of the longitudinal axis of the hot gas generator and not transversely thereto, is known, for example, from DE 1 501 984 A.

[0007] Known disadvantages of conventional hot gas generators include

- that a large installation area must be available;

- that a high fan power must be provided due to pressure losses during the supply of the gas to be heated;

- that a great deal of effort is required to achieve the desired homogenisation of the hot gas in the downstream line, particularly where the distances between the hot gas generator and the devices requiring the hot gas are short;

- that the hot gas generator must be oversized, since a conventional hot gas generator must usually be suitable for a wide variety of heating media and is not adapted to the individual fuel.

[0008] The invention is based on the object of providing a hot gas generator of the type mentioned at the outset which does not have the disadvantages of the prior art. In particular, a hot gas generator which is as compact as possible is to be provided which achieves a very high degree of homogenization of the hot gas despite its small size.

[0009] This object is achieved according to the invention with a hot gas generator having the features of claim 1.

[0010] Preferred and advantageous embodiments of the invention are the subject of the subclaims.

[0011] According to the invention, it is provided that the supply section extends over the entire width of the supply line running in the axial direction and that the generator casing in the supply section runs spirally around the longitudinal axis, so that the swirl channel in the supply section tapers around the flame tube, starting from the supply line.

[0012] The spiral-shaped supply of the gas or gas mixture to be heated ensures that the speed of the gas or gas mixture is (approximately) the same over the entire circumference of the spiral-shaped supply. This guarantees that the gas or gas mixture to be heated is distributed very evenly upon entry into the swirl channel. In contrast to an annular gas supply, this even distribution reduces the differential pressure.

[0013] The supply line opens into the generator casing laterally or transversely to the longitudinal axis. The supply line preferably has a rectangular cross-section and in particular has a greater width (which extends essentially in the axial direction) than height (which extends essentially transversely to the axial direction).

[0014] The flame tube is lined with, for example, refractory concrete, fireclay, ceramic fibers or another refractory material. The combustion chamber is smaller than the internal volume of the flame tube because the refractory lining has a certain wall thickness.

[0015] The burner leading into the combustion chamber can be, for example, a gas or oil burner.

[0016] In the context of the invention, a spiral course of the generator casing means that the generator casing, seen in a cross-section through the hot gas generator along a cutting plane aligned orthogonally to the longitudinal axis, "screws" in a spiral around the longitudinal axis. This means that the casing, starting from the area in which the supply line opens into the swirl channel, continuously approaches the longitudinal axis as it circles around the latter (as a result of which the width of the swirl channel - i.e. a distance between the generator casing and the flame tube - continuously decreases) until it again meets the area in which the supply line opens into the swirl channel and in which the supply section has the greatest width.

[0017] The fact that the flame tube is at least partially encased by the generator casing means within the scope of the invention that the supply end does not extend to the burner end of the flame

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but can also be spaced apart from it in the direction of the longitudinal axis, so that not the entire flame tube or the entire combustion chamber bordered by the lined flame tube is encased by the generator jacket. That part of the flame tube which extends in the axial direction between the supply end of the generator jacket and the outlet end of the flame tube is, however, encased by the generator jacket (preferably entirely).

[0018] The gas or gas mixture to be heated (hereinafter also referred to simply as “gas to be heated”), for the temperature increase of which the hot gas generator according to the invention is designed, is in particular air or another gas or gas mixture, an exhaust gas or a flue gas.

[0019] Within the scope of the invention, it is particularly preferred if the generator casing in the feed section runs spirally around the longitudinal axis in the form of at least part of an Archimedean spiral (in particular in a complete spiral circuit around the longitudinal axis). The course of an Archimedean spiral is well known and does not need to be described in more detail here. The Archimedean spiral shape (or worm shape) ensures that the speed of the gas to be heated is as precisely as possible the same over the entire circumference of the spiral-shaped feed.

[0020] Particularly preferably, guide plates are arranged in a swirl section of the swirl channel that runs axially from the supply section in the direction of the connection end, bridging the swirl channel radially. The guide plates are arranged at an angle to the longitudinal axis and in a helical shape around the flame tube, so that between each two guide plates arranged next to each other a partial channel is formed that screw or wind around the flame tube. The gas to be heated flowing from the supply section through the swirl channel flows through the partial channels and is thereby set in rotation around the flame tube. As a result, the gas flow of the gas to be heated at the end of the swirl channel not only has a movement component in the axial direction, but also a movement component in the circumferential direction.

[0021] In particular, the swirl channel in the swirl section, running around the flame tube, has a substantially constant width. This ensures that the gas to be heated is "swirled" as homogeneously as possible.

[0022] Within the scope of the invention, it can be provided that the generator casing tapers conically in a constriction region arranged between the swirl channel and the connection end. This constriction region can be directly connected to the swirl channel or to the connection end, but it can also be spaced apart from it. An inner diameter of the generator casing at the end of the constriction region is preferably a maximum of 90%, in particular a maximum of 80%, preferably a maximum of 70%, of the inner diameter of the generator casing at the beginning of the constriction region. The "constriction" of the flow consisting of the flue gas and the gas to be heated in the constriction region leads to a further increase in the homogeneity of the hot gas.

[0023] Within the scope of the invention, it is also possible for a funnel guide plate to be arranged within the generator casing, which extends around the longitudinal axis and is inclined at an angle of 20° to 70°, in particular 30° to 60°, to the longitudinal axis. The funnel guide plate forms a funnel that tapers towards the connection end, which has a wide end (all the way around and tightly) connected to the generator casing and a narrow end that projects freely into the generator casing. The funnel guide plate is arranged in particular after the swirl channel (i.e. between the swirl channel and the connection end), e.g. directly after it or at a distance from it, but can also be arranged in the swirl channel at least with its wide end. If a constriction area is present, the funnel guide plate is preferably arranged in the constriction area (at least with its wider end, but in particular entirely). The funnel guide plate (like a constriction area) ensures a further increase in the homogeneity of the hot gas and can be provided instead of a constriction area or in addition to it (in order to constrict the gas flow even further). Such a

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Funnel plate is provided in particular when the connection opening is relatively large and a constriction area alone only leads to a small “constriction” (since the inner diameter of the generator casing at the end of the constriction area would only be insignificantly smaller than at its beginning).

[0024] Within the scope of the invention, it is preferred that the swirl channel encloses at least 50% of the combustion chamber in the axial direction. However, the swirl channel can also enclose at least 75% or even essentially 100% of the combustion chamber. With such a long swirl channel, a particularly uniform distribution of the gas to be heated takes place in the direction of the outlet end of the combustion chamber.

[0025] It is also preferred if the supply section extends in the axial direction over at least 60%, preferably at least 80%, of the swirl channel. Such a long supply section, which originates from a correspondingly wide supply opening, also promotes the distribution of the gas to be heated in the swirl channel.

[0026] In particular, within the scope of the invention, an embodiment is preferred in which the swirl channel is delimited in the radial direction towards the longitudinal axis by an inner tube which is tightly connected to the flame tube in the region of the outlet end and extends to the supply end. The inner tube preferably ends at the outlet end and does not protrude beyond the outlet end in the direction of the connection end. Likewise, the inner tube preferably ends at the supply end and does not protrude beyond this. A circular flange can be provided for a tight connection all around between the flame tube and the inner tube. A cooling gap enclosing the flame tube is formed by the inner tube between the flame tube and the swirl channel (which is delimited by the inner tube in the radial direction towards the flame tube). Ambient air can flow through or through this cooling gap. The axial length of the cooling gap preferably corresponds to the axial length of the swirl channel, since the inner tube is connected to the flame tube in the region of the outlet end. Even if the cooling gap is located between the swirl channel and the flame tube, the flame tube is nevertheless to be regarded as enclosed by the swirl channel within the scope of the invention.

[0027] In principle, the cooling gap serves to ventilate the flame tube in order to prevent it from overheating. Since the flame tube is exposed to the high temperatures of the flue gas despite the fireproof lining, it can happen that it expands more in the radial and also axial direction than the generator casing, which is heated less by the gas to be heated. The cooling gap thus prevents mechanical stresses from occurring in the hot gas generator due to the different, temperature-related expansions between the flame tube and the generator casing.

[0028] Preferably, the cooling gap around the flame tube has a substantially constant width so that the flame tube can expand equally in all directions. The width of the cooling gap can be adapted to the respective operating conditions of the hot gas generator and can be, for example, between 2 mm and 200 mm, in particular between 5 mm and 100 mm. For example, the width of the cooling gap when the hot gas generator is not in operation can be approximately 5-10 mm for a "cooler" gas and approximately 50-100 mm for a "hotter" gas to be heated.

[0029] Within the scope of the invention, it can be provided that a separating web runs in the axial direction in the supply section. This separating web separates a region of the supply section into which the supply line opens and in which the swirl channel is maximally wide (i.e. in which a radial width of the swirl channel is greatest) from a region of the supply section in which the swirl channel is maximally tapered (i.e. a region in which a radial width of the swirl channel is smallest and which is arranged directly next to the region that is maximally wide). The separating web preferably separates the two regions tightly from one another, but it can also have gas passages. The separating web extends in particular over the entire axial length of the supply section. The separating web prevents the gas to be heated from the supply line from flowing directly into the area of the swirl channel that is maximally tapered, so that the gas to be heated is forced to enter the flame tube into that

Direction in which the swirl channel continues to taper, i.e. in which the radial width of the swirl channel continues to decrease as it flows around. This leads to an even distribution of the gas to be heated in the swirl channel (or possibly in the swirl section of the swirl channel) and ultimately to better homogeneity of the hot gas.

[0030] Further details, features and advantages of the invention emerge from the following description of preferred embodiments with reference to the attached drawings. It shows:

[0031] Fig. 1 shows a conventional hot gas generator in a side sectional view along a cutting plane running vertically and in the direction of a longitudinal axis of the hot gas generator,

[0032] Fig. 2 shows the hot gas generator shown in Fig. 1 in a front view,

[0033] Fig. 3 shows a hot gas generator according to the invention in a lateral sectional view along a cutting plane running vertically and in the direction of the longitudinal axis of the hot gas generator,

[0034] Fig. 4 is a sectional view through the hot gas generator shown in Fig. 3 along the section plane III-III,

[0035] Fig. 5 the hot gas generator according to the invention in a partially cutaway isometric view,

[0036] Fig. 6 shows the hot gas generator according to the invention according to a further embodiment in a lateral sectional view along a cutting plane running vertically and in the direction of the longitudinal axis of the hot gas generator,

[0037] Fig. 7 shows a detail of the hot gas generator shown in Fig. 6.

[0038] Fig. 1 shows a conventional hot gas generator 1, wherein the hot gas generator 1 in Fig. 1 is shown cut along a cutting plane which runs vertically and along a longitudinal axis L of the hot gas generator 1.

[0039] In Fig. 2, the hot gas generator from Fig. 1 is shown in a front view.

[0040] The known hot gas generator 1 has a burner 2 for generating flue gas, which opens into a combustion chamber 3.

[0041] The combustion chamber 3 is surrounded by a flame tube 4 which has a lining 5 made of a refractory material, for example refractory concrete or ceramic fibers.

[0042] The flame tube 4 has a closed burner end 6, at which the burner 2 opens into the combustion chamber 3, and an open outlet end 7.

[0043] The flame tube 4 is arranged within a tubular generator casing 8 which has an inner diameter which is larger than an outer diameter of the flame tube 4, so that an annular gap, namely the swirl channel 9, is formed between the generator casing 8 and the flame tube 4.

[0044] The tubular generator casing 8 extends from a supply end 11, which terminates at the burner end 6, to a connection end 12, which opens into a connection opening 13. Further lines can be connected to the connection opening 13, which lead to devices (not shown) requiring hot gas.

[0045] From the side, i.e. transversely to the longitudinal axis L, a supply line 14, the line cross-section of which is aligned orthogonally to a pipe cross-section of the flame tube 4 or the generator casing 8, opens into the swirl channel 9. A gas or gas mixture to be heated or heated (hereinafter: "gas to be heated") can be introduced into the generator casing 8 through this supply line 14, which flows along the swirl channel 9 and mixes with the flue gas flowing out of the combustion chamber 2 at the outlet end 7 of the flame tube. The supply line 14 of the hot gas generator 1 shown has a circular line

cross-section.

[0046] The hot gas formed from the mixing of flue gas and gas to be heated flows through a static mixing element 15 arranged in the generator casing 8 in the direction of the connection end 12 and exits the hot air generator 1 via the connection opening 13. The static mixing element 15 has, for example, free-standing or interconnected webs and sheets which form a forced guide for the hot gas flow and ensure better mixing so that the mixing temperature of the resulting hot gas is homogenized.

[0047] In Fig. 3, a hot gas generator 1 according to the invention is shown in a side sectional view, wherein the sectional plane runs vertically and in the direction of the longitudinal axis L of the hot gas generator 1.

[0048] Fig. 4 shows a cross section through the hot gas generator 1 according to the invention along a sectional plane III-III shown in Fig. 3.

[0049] In Fig. 5, the hot gas generator 1 according to the invention is shown according to a further embodiment in a partially cutaway, isometric view.

[0050] The hot gas generator 1 according to the invention has a similar structure to the conventional hot gas generator 1 shown in Figs. 1 and 2. In the following, therefore, the same reference numerals are used for identical and similar components and components.

[0051] The combustion chamber 3 with the burner 2 opening into it is also surrounded by the lined flame tube 4 with the closed burner end 6 and the open outlet end 7 in the hot gas generator 1 according to the invention and does not differ from the combustion chamber 3 of the conventional hot gas generator 1 shown in Fig. 1.

[0052] In the hot gas generator 1 according to the invention, the generator casing 8 also encloses the flame tube 4, so that the swirl channel 9 is formed between the generator casing 8 and the flame tube 4. The supply end 11 of the generator casing 8 is spaced from the burner end 6 of the flame tube 4 in the illustrated hot gas generator 1 according to the invention, so that the flame tube 4 or the combustion chamber 3 is not completely enclosed by the generator casing 5 and the swirl channel 9, but only partially.

[0053] The swirl channel 9 of the hot gas generator 1 according to the invention is divided into a supply section 16 (in the embodiment shown) adjoining the supply end 11 and a swirl section 17 adjoining the supply section 16 and extending to the outlet end 8.

[0054] The supply section 16 of the hot gas generator 1 according to the invention extends over the entire axial width Z of the supply line 14, which in the embodiment shown has a rectangular line cross-section.

[0055] As can be seen in Fig. 4, the generator casing 8 in the supply section 16 runs spirally (in the form of part of an Archimedean spiral) around the longitudinal axis L and also around the flame tube 4. A radial width B of the swirl channel 9 is greatest in a first region 18 of the supply section 16, into which the supply line 16 opens, and continues to decrease around the flame tube 4. In a second region 19 of the supply section 16, which directly borders the first region 18, the radial width B of the swirl channel 9 is smallest.

[0056] A separating web 21, which runs axially along the flame tube 4 in the supply section 16, separates the first region 18 from the second region 19. The gas to be heated, which enters the swirl channel 9 via the supply line 14, therefore flows around the flame tube 4 in an anti-clockwise direction in the embodiment shown. The swirl channel 9 also tapers in an anti-clockwise direction starting from the first region 18 (i.e. from the supply line 14), i.e. it becomes increasingly narrower and has an increasingly smaller radial width B.

[0057] The arrows shown in Fig. 4 indicate that the gas to be heated is distributed around the

flame tube 4 from the supply section 16 with uniform pressure into the vortex section 17 of the swirl channel 9.

[0058] In the vortex section 17, guide plates 22 are arranged which radially bridge the swirl channel 9 (i.e. run from the generator casing 8 to the flame tube 4). The guide plates 22 are evenly distributed around the flame tube 4 and are arranged or inclined at an angle to the longitudinal axis L so that they run helically around the flame tube 4 (or along the flame tube 4). Each of the guide plates 22 runs only around part of the circumference of the flame tube 4 and not around the entire flame tube 4. The guide plates 22 extend over the entire axial length of the vortex channel 17.

[0059] In Fig. 5, the flame tube 4 together with the associated lining 5 is “cut free” in a lower region in order to better illustrate the helical course of the guide plates 22 of the mixing element 15 in the vortex region 17.

[0060] Between the outlet end 7 of the flame tube 4 (or the swirl channel 9) and the connection end 12, the generator casing 8 has a constriction region 23 in which the generator casing 8 tapers towards the connection end 12. An inner diameter | of the generator casing 8 decreases from the beginning of the constriction region 23 to its end.

[0061] Unlike the conventional hot gas generator 1 shown in Figs. 1 and 2, the hot gas generator 1 according to the invention does not require an additional mixing element 15 arranged after the swirl channel 9. Due to the optimized pressure distribution of the gas to be heated and the swirling of the gas to be heated that already occurs in the swirl region 17 (without an additional mixing element being required), the total length (structure length) of the hot gas generator 1 according to the invention can be significantly shorter than in conventional hot gas generators 1.

[0062] Fig. 6 shows the hot gas generator 1 according to the invention according to a further embodiment and Fig. 7 shows a detail D from Fig. 6 in an enlarged view.

[0063] The hot gas generator 1 according to the invention shown in Figs. 6 and 7 differs only in the following details from the hot gas generator 1 according to the invention shown in Figs. 3 and 4:

[0064] On the one hand, the swirl channel 9 (in particular the supply section 16 of the swirl channel 9) in the hot gas generator 1 shown in Fig. 6 is shorter than in the hot gas generator 1 shown in Figs. 3 and 4.

[0065] On the other hand, in the hot gas generator 1 shown in Fig. 6, an inner tube 25 is arranged between the generator casing 8 and the flame tube 4, which inner tube delimits the swirl channel 9 inwards, i.e. towards the longitudinal axis L. The inner tube 25 runs from the supply end 11 of the generator casing 8 to the outlet end 7 of the flame tube 4 and is tightly connected, e.g. welded, to the flame tube 4 at the outlet end 7 via an annular flange 26.

[0066] In the detail D shown in Fig. 7, it can be seen that a cooling gap K is formed between the inner tube 25 and the flame tube 4, through which ambient air can flow or be flushed from the supply end 11. The cooling gap K preferably has a constant width (seen in the radial direction) around the flame tube 4.

[0067] Of course, hot gas generators 1 are also conceivable within the scope of the invention which comprise a combination of the features of the above-described embodiments of hot gas generators 1 according to the invention.

REFERENCE SYMBOL LIST

1 hot gas generator 2 burners

3 combustion chambers

4 flame tube

5 Lining 6 Burner end 7 Exit end

8 Generator jacket 9 Swirl channel 10 =

11 feed end

12 Connection end 13 Connection opening 14 Supply line

15 mixing element

16 Supply section 17 Vortex section 18 First area

19 second area

20 ---

21 divider

22 baffle

23 Constriction area 24 =

25 inner tube

26 flange

L longitudinal axis

Z Width of supply line

B radial width of swirl channel

| Inner diameter generator casing D Detail

K cooling gap

Claims (10)

patent claims 1. Hot gas generator (1) with a longitudinal axis (L), comprising * a burner (2) for generating flue gas, * a combustion chamber (3) which is surrounded by an axially extending, refractory-lined flame tube (4) which is closed at a burner end (6) at which the burner (2) opens into the combustion chamber (3) and is open at an outlet end (7), * an axially extending, essentially tubular generator casing (8) which extends from a supply end (11) arranged in the direction of the burner end (6) to a connection end (12) which projects beyond the outlet end (7) and opens into a connection opening (13) and thereby encloses the flame tube (4) at least in sections, wherein a swirl channel (9) extending from the supply end (11) in the direction of the connection end (12) and enclosing the flame tube (4) is formed between the generator casing (8) and the flame tube (4), and * a supply line (14) for supplying a gas or gas mixture to be heated or heated, which opens into a supply section (16) of the swirl channel (9) and whose line cross-section is aligned transversely, in particular orthogonally, to a tube cross-section of the flame tube (4), characterized by that the feed section (16) extends over the entire axial width (Z) of the feed line (14), and that the generator casing (8) in the feed section (16) runs spirally around the longitudinal axis (L), so that the swirl channel (9) in the feed section (16) tapers around the flame tube (4) starting from the feed line (14). 2, Hot gas generator according to claim 1, characterized in that the generator casing (8) in the supply section (16) extends spirally around the longitudinal axis (L) in the form of at least a part of an Archimedean spiral. 3. Hot gas generator according to claim 1 or 2, characterized in that guide plates (22) are arranged in a swirl section (17) of the swirl channel (9) extending axially to the supply section (16) in the direction of the connection end (12), wherein the guide plates (22) radially bridge the swirl channel (9) and are arranged at an angle to the longitudinal axis (L) and helically around the flame tube (4). 4. Hot gas generator according to claim 3, characterized in that the swirl channel (9) in the swirl section (17) running around the flame tube (4) has a substantially constant width (B). 5. Hot gas generator according to one of claims 1 to 4, characterized in that the generator casing (8) tapers conically in a constriction region (23) arranged between the swirl channel (9) and the connection end (12), wherein an inner diameter (I) of the generator casing (8) at the end of the constriction region (23) is a maximum of 90%, in particular a maximum of 80%, preferably a maximum of 70%, of the inner diameter (I) of the generator casing (8) at the beginning of the constriction region (23). 6. Hot gas generator according to one of claims 1 to 5, characterized in that inside the generator casing (8), in particular after the swirl channel (9), a funnel guide plate is arranged which runs around the longitudinal axis (L) and is inclined at an angle of 20° to 70°, in particular of 30° to 60°, to the longitudinal axis (L), so that it forms a funnel which tapers in the direction of the connection end (12), which adjoins the generator casing (8) with a wide end and projects freely into the generator casing (8) with a narrow end. 7. Hot gas generator according to one of claims 1 to 6, characterized in that the swirl channel (9) encloses at least 50%, preferably at least 75%, in particular substantially 100%, of the combustion chamber (3) in the axial direction. 8. Hot gas generator according to one of claims 1 to 7, characterized in that the supply section (16) extends in the axial direction over at least 60%, preferably at least 80%, of the swirl channel (9). 9. Hot gas generator according to one of claims 1 to 8, characterized in that the swirl channel (9) is delimited in the radial direction towards the longitudinal axis (L) by an inner tube (25) which is tightly connected to the flame tube (4) in the region of the outlet end (7) and extends to the supply end (11), so that a cooling gap (K) enclosing the flame tube (4) is formed between the flame tube (4) and the swirl channel (9). 10. Hot gas generator according to one of claims 1 to 9, characterized in that a separating web (21) runs in the axial direction in the supply section (16), which preferably seals off a first region (18) of the supply section (16), into which the supply line (14) opens and in which the swirl channel (9) is maximally wide, from a second region (19) of the supply section (16), in which the swirl channel (9) is maximally tapered. 4 sheets of drawings