DE1053873B - Flame stabilization device - Google Patents

Description

GERMAN

The main patent application relates to a device for holding and stabilizing the flame in one A high-speed stream flows through the combustion chamber by means of gaseous screens, which are from Auxiliary jets penetrating transversely into the stream are formed, which through nozzle-like blow openings which are fed with air or another gas, the pressure of which is higher than that in the Combustion chamber is the prevailing pressure, the air or gas being arranged outside the combustion chamber Is taken from the source and preferably mixed with fuel.

It has been found that with certain combustion chambers, particularly with afterburning nozzles of jet engines, the combustion generates strong vibrations, which can quickly lead to damage being able to lead.

The purpose of the invention is to take precautions in a device according to the main patent application meet which allow such vibrations to be prevented.

According to the invention, the nozzle-like blow openings have with respect to the direction of the flow different orientations so that they produce at least two screens formed by auxiliary beams, which are inclined with respect to each other.

The nozzle-like blow openings can run on either side perpendicular to the direction of the flow Be inclined plane so that the emerging from them auxiliary beams downstream or upstream are inclined.

In a preferred embodiment of the invention, the nozzle-like blow openings are over at least two successive rows distributed, the nozzle-like blow openings in one and in the same row have the same inclination, so that the two gaseous ones produced by the auxiliary jets Umbrellas form two conical surfaces of different conicity.

There is known a combustion device in which in the one passing through the combustion chamber Stream a solid conical screen, the tip of which points in the downstream direction, so arranged is that it takes up gas from the stream itself and through holes provided in the screen wall the outside of the screen leads behind a baffle that extends transversely into the flow, around which Gas escaping through the holes with sprayed against the conical outside of the fixed screen Mixing fuel. In contrast, the invention relates to gaseous screens that are generated by nozzle-like blow openings, which are fed with a pressurized auxiliary gas that a flame stabilization device outside the combustion chamber

Addition to patent application S35305Ia / 46g
(Interpretation document 1 049 640)

Applicant:
Societe Nationale d'Etude

et de Construction de Moteurs d'Aviatiön, Paris

Representative: Dr. E. Wiegand, Munich 9,

and Dipl.-Ing. W. Niemann, Hamburg 1,

Ballindamm 26, patent attorneys

Claimed priority:
France, May 13, 1955

Jean Henry Bertin, Neuilly-sur-Seine, Seine,
and Benjamin Jean Marcel Salmon, Suresnes, Seine

(France),
have been named as inventors

arranged source is taken. These gaseous screens can be selected as required can be made to work or completely disappear, which is when using a solid screen not possible.

The invention is explained in more detail with reference to the drawing, for example.

Figures 1, 2 and 3 are axial sections of three embodiments of one made in accordance with the invention Afterburning nozzle;

Figure 4 is a fragmentary sectional view, on an enlarged scale, taken through the axis of the nozzle Level;

Figure 5 is a section on line V-V of Figure 3;

Fig. 6 is an axial section through an afterburning nozzle in which the screen generating Auxiliary gas also ensures cooling of the parts containing the nozzle-like blow openings.

The drawing shows the special case in which the gaseous Nozzle-like blow openings or

80Ϊ 787/187

Blow lines are arranged in a body 1 which extends along the axis of the combustion chamber 2. Such a body is generally provided for afterburning nozzles of jet engines, in order to close an aerodynamically designed cap (outflow cone) over the turbine (not shown) (which would be located on the left-hand side of FIG. 1) form which the flow of the gases coming from the turbine against the outlet opening of the nozzle (on the right side of the drawing) relieved. However, this embodiment is not the only one possible; the nozzle-like blow lines could also be arranged in other ways, for example on the wall of the nozzle or in rings or other parts arranged in the afterburning chamber.

1 and 2 illustrate a first embodiment, in which the nozzle-like blow lines of the body 1 are arranged in two rows 4 α and 4 b and are oriented in different directions from one row to the other, so that the auxiliary gas jets emerging from these blow lines form the generatrices of two conical surfaces which have opposite conicity. It has been found that this arrangement makes it possible to eliminate the vibrations, which can undoubtedly be explained by an influence on the propagation of the pressure waves which are generated during the combustion. At least two successive flame fronts are generated at different points, which lead to the superposition of at least two vibration states, which counteract each other for a suitable starting point of the flame fronts and can cancel out their influences.

The rows of nozzle-like blower lines 4 a and 4 b can be formed by small holes drilled in the wall of the body 1 and fed with an auxiliary medium, for example with air, which is taken from the compressor of the engine and provided in the annular collecting spaces 5 within the body 1 (see. Fig. 4) is supplied. The blow lines 4 a and 4 & can be designed as expansion lines which give the auxiliary medium jets f (Fig. 4) the maximum amount of movement in order to promote the penetration of these jets into the gas flow by: them tubular parts 6 of a certain length (Fig 4), which are fixed in the body 1.

3 and 5 show a modified embodiment in which the blow lines belonging to the same ring lying in the plane VV have alternately different slopes so that, if one follows the path of the ring, one successively, for example, a blow line from of inclination zero, that is, the axis of which is perpendicular to axis AA of the combustion chamber, a blow pipe with inclination + d, a blow pipe with inclination zero, a blow pipe with inclination - δ , and so on. Of course, several so formed rings of blow lines can be arranged one behind the other with variable spacings, and also several double rings of the type described in connection with FIGS. 1 and 2 can be provided; the various arrangements described in connection with the drawing can also be combined with one another in various ways.

Fig. 6 shows how a circulation of air, which generates the medium screens, can be effected in order to cool the wall of the body 1 to ensure. The air that is taken from the engine's compressor, for example, arrives through a line 8 in a disposed at the rear end of the body 1 chamber 9 and from there to the Wreaths of nozzle-like blow lines 4a and 4 fr, whereby it passes through an annular channel 10 which is formed between the wall of the body 1 and a stepped inner wall 11 is formed. The wall of the body 1 experiences in this way effective cooling.

In all of the embodiments described above, the fuel in the combustion chamber to be burned, wholly or partially injected into the air, some or all of the the medium shields generating 'feeds nozzle-like lines or openings. When part of the Fuel is introduced in this way, the carbonated air, which from the openings or some of them are ignited before the main combustion to create a pilot flame.

Claims (6)

Patent claims: 1. Means for holding and stabilizing the flame in one of a high velocity stream flow through the combustion chamber by means of gaseous screens that penetrate from across the stream Auxiliary jets are formed, which are generated by nozzle-like blow openings, those with air or another. Gas fed, the pressure of which is higher than that in the combustion chamber The prevailing pressure is, with the air or gas outside the combustion chamber arranged source is taken and preferably mixed with fuel, according to patent application S 35305 Ia / 46 g, characterized in that the nozzle-like blow openings (4) with reference to the Direction of the current have different orientations, so that they have at least two auxiliary beams produce formed screens that are inclined with respect to one another. 2. Device according to claim 1, characterized in that the nozzle-like blow openings (4) are inclined on both sides of a plane perpendicular to the direction of the current, so that the auxiliary jets emerging from them are inclined upstream and downstream, respectively. 3. Device according to claim 2, characterized in that the nozzle-like blow openings (4) are distributed over at least two successive rows (4 a, 4 &), the nozzle-like Blow openings in one and the same row have the same inclination, so that the two Gaseous screens produced by the auxiliary jets have two different conical surfaces Form conicity. 4. Device according to claim 2, characterized in that the nozzle-like blow openings (4) in one and the same row are inclined alternately to opposite sides (+ δ, -δ) (Fig. 3). 5. Device according to one of claims 1 to 4, characterized in that the nozzle-like Blower openings (4) are provided in a central body (1) which is on the axis of the combustion chamber and in the case of an afterburning chamber on that of the turbine jet engine behind the Turbine wheel is arranged. 6. Device according to claim 5, characterized in that that the nozzle-like blow openings (4) are fed via a channel (9) which is in the vicinity of the wall of the central body (1) is arranged, so that the through this channel gaseous gases flowing through under pressure Medium along the wall and. she cools. References considered: U.S. Patent No. 2,529,506. 1 sheet of drawings © 809 787/187 3.59