US3007310A - Combustion chamber with vorticity of the combustible mixture - Google Patents

Description

Nov. 7, 1961 K. EISELE 3,007,310

COMBUSTION CHAMBER WITH VORTICITY OF THE COMBUSTIBLE MIXTURE 2 Sheets-Sheet 1 Filed May 15, 1956 COMPRESSOR 28 INVENTOR KARL E ISELE BY ,Lckl, M ATTORNEYS Nov. 7, 1961 K. EISELE 3,007,310

COMBUSTION CHAMBER WITH VORTICITY OF THE COMBUSTIBLE MIXTURE Filed May 15, 1956 2 Sheets-Sheet 2 INVENTOR. KARL E IS ELE A TTORNE Y5 hit Patented Nov. 7, 1361 3,907,310 COMBUSTION CHAMBER WITH VURTICITY OF THE COMBUSTIBLE MIXTURE Karl Eisele, Fellbach, near Stuttgart, Germany, assignor to Daimler-Benz Aktiengesellsehaft, Stuttgart-Untanturkheim, Germany Filed May 15, 1956, Ser. No. 584,981 Claims priority, application Germany May 25, 1955 6 Claims. (Cl. 6039.69)

The present invention relates to a burner or combustion chamber for combustion engines such as combustion turbines, propulsion gas producers, jet propulsion engines, etc., in which a batde plate is arranged within the burner or combustion chamber in order to produce an annular Whirl in the core of the burner or combustion chamber which affects favorably the mixture of the fuel introduced ahead of the baffle plate with the combustion air and therewith also the combustion processes themselves.

More particularly, the present invention relates to a burner or combustion chamber of the described type in which a rotary movement about the longitudinal axis of the burner or chamber is imparted additionally to the combustion air at the entrance into the burner or combustion chamber by means of an inlet spiral or a screen with appropriately directed vanes or any other suitable manner.

Accordingly, it is an object of the present invention to provide a construction for a burner or combustion chamber of combustion engines in which the combustion processes are favorably affected.

.A further object of the present invention is to provide a construction which increases the flame stability and rate of heat release of the fuel due to more intimate mixing of the combustion fuel with the combustion air.

Still another object of the present invention resides in the provision of a burner or combustion chamber of a combustion engine which is compact and simple structure and of relatively short length.

A still further object of the present invention is to provide such a construction of a burner or combustion chamber for combustion engines of any type, particularly those for use with hydrocarbon fuels rich in carbon, in which the combustion air is subjected to a spiral movement about the axis of the burner or chamber and in which a toroidal or annular whirl is superimposed upon the spirial movement.

A still further object of the: present invention is to provide an advantageous pretreatment of the fuel preferably by preheating and premixing with a limited amount of combustion air prior to the injection into the burner itself.

These and other features, objects and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing, which shows for purposes of illustration only several preferred embodiments in accordance with the present invention, and wherein:

FIGURE 1 is an axial cross sectional view through the burner or combustion chamber of one embodiment in accordance with the present invention.

FIGURE 2 is an axial cross sectional view similar to FIGURE 1 of a different embodiment of a burner or combustion chamber in accordance with the present invention.

FIGURE 3 is an axial cross sectional view similar to FIGURE 1 illustrating a still further modification of a burner or combustion chamber in accordance with the present invention.

FIGURE 4 is an axial cross sectional view through still another modification of a burner or combustion chamber in accordance with the present invention.

FIGURE 5 is a cross-sectional view of the air inlet spiral taken along line VV of FIGURE 1, and

FIGURE 6 is a cross-sectional view through the combustion chamber along line VIVI in FIGURES 5 and 6.

In combustion chambers or burners of this type of the prior art, the fuel is admixed to the combustion air directly ahead of the baffle plate. However, it has been demonstrated that this type of admixture of the fuel is not sufficient notwithstanding the combustion aid rendered by means of the aforementioned annular whirl and possibly also by means of the rotary movement imparted to the combustion air in order to obtain a satisfactory unobjectionable combustion, especially in case of use of fuels rich in carbon, over the shortest possible path. These disadvantages and inadequacies of the prior art are obviated by the present invention.

The present invention is based on the recognition that it is not possible with the baffie plate alone to achieve an annular whirl of sufficient intensity, especially in the inner part thereof in which the flow of combustion air is opposite to the main direction of flow thereof, in order to achieve a sufficiently rapid and thorough mixing of the supplied fuel with the combustion air.

Accordingly, the present invention consists in that a discharge pipe is arranged within the combustion chamber, preferably in the center of the annular whirl, which discharge pipe terminates, as seen in the main direction of flow of the combustion air, ahead of the baffle plate. Additional combustion air is supplied by means of this discharge tube to the burner or combustion chamber in a direction opposite to that of the main direction of flow of the combustion air in order to increase the kinetic energy of the annular whirl. The fuel is appropriately admixed already with this additional or auxiliary combustion air ahead of the discharge thereof into the combustion chamber so that a mixture consisting of premixed fuel and additional air is blown or discharged into the annular whirl.

Referring now more particularly to the drawing wherein like reference numerals are used throughout the various views to designate like parts and more particularly to FIGURE 1, reference numeral 5 designates the burner or combustion chamber. The main combustion air is supplied to the combustion chamber 5 from the line 6 through an inlet spiral '7, as shown in FIGURE 5, or the like of any suitable construction so that the main combustion air, in addition to the longitudinal movement thereof, undergoes a rotary movement about the longitudinal axis 3 within the combustion chamber 5, as indicated by the arrows 9. The main combustion air thus seeks to traverse the combustion chamber 5 from right to left, as viewed in FIGURE 1, while at the same time carrying out a rotary movement about the axis 8 which is clockwise as viewed from the left end or battle plate side of the combustion chamber 5.

A baflie plate It is arranged within the core of the helically-shaped movement of the main combustion air obtained in the manner described hereinabove, the baflle plate being disposed essentially transversely to the longitudinal axis 8. The baffie plate It) is carried by a tube or pipe 11 which extends into the combustion chamber 5 centrally thereof. As a result of the baffle plate 10 a partial return flow of the main combustion air within the combustion chamber 5 is produced so that an annular whirl of toroidal shape as indicated by the arrows 12 is superimposed on the helically-shaped movement of the main combustion air as indicated by the arrows 9 thereof into which the fuel is injected in a manner to be described more fully hereinafter.

According to the present invention additional or auxiliary combustion air is supplied to the core of the annular whirl 12 by means of the tube 11 which terminates at 13 ahead of the baflle plate 10, all reference being taken with respect to the general direction of flow 15 of the main combustion air. The air discharged from the pipe 11 is in the direction of the arrow 14, i.e., in a direction opposite to the general movement 15 of the rain combustion air and aids to sustain the annular whirl within the core or inner part thereof.

The additional or auxiliary combustion air may be supplied from the same pressure source as the main combustion air, for example, from the same compressor which may be connected ahead of the burner or combustion chamber, as shown in FIGURE 1. However, it may also be supplied from a separate compressor or from a higher compression stage than the main combustion air of the common compressor having a plurality of compression stages which supply the different pipes 6 and 11.

The kinetic energy of the annular whirl 12 is considerahly increased by the injection of the additional combustion air into the core so that a considerably better turbulence and improved mixing of the supplied fuel with the main mass of the combustion air and therewith a more rapid and more complete combustion thereof over the smallest possible space takes place than could be obtained with the whirl produced solely with the aid of the baflie plate 10.

The supply of the gaseous or liquid fuel takes place by means of the line 16 at the end of which an appropriately-shaped injection nozzle 17 may be provided which may be located within the discharge line 11 for the additional air so that a pre-mixture enters the combustion chamber through the orifice 13 and the combustion process is further sped up. An ignition means 37 is provided and shown schematically in the discharge line 11 for initial ignition of the combustible mixture. The mixture which over its continued path through the combustion chamber burns completely, thereupon reaches together with the excess air which is also heated by the combustion gases an engine or the runner blades of a turbine wheel whereby the energy imparted to the gases by the heating thereof is transformed in a known manner into mechanical energy.

The embodiment according to FIGURE 2 distinguishes itself from that of FIGURE 1 essentially by the fact that the supply line 21 for the additional air is introduced into the combustion chamber 5 from the entrance side 20 thereof and that a cylindrical guide member 23 is secured to the batfle plate in front of the orifice 22 of the line 21 which together with the battle plate 10 forms a deflection member of cupped-shape so as to change the pre-mixture discharged from the line 21 by 180 degrees in the direction of the arrow 14. Furthermore, the supply line 26 for the fuel in that case discharges into the line or pipe 21 for the additional air near the inlet side of the combustion chamber 5. As this line 21 which lies within the flame Zone of the combustion chamber is strongly heated during operation, the fuel contained in the premixture is thereby pre-heated and consequently completely before it reaches the combustion chamber which contributes to the further acceleration and improvement of the combustion processes in the combustion chamber 5.

An insert member 27, as also shown in FIGURE 6, and designed to impart rotary movement to the additional air is provided in the line 21 ahead of the orifice of the fuel line 26. The insert member 27 may be made, for example, of helically-twisted sheet metal strips or members arranged in a spoke-like manner by means of which an intensive turbulence of the additional air prior to its admixture with the fuel takes place. This insert member 27 which causes the turbulence of the additional air simultaneously serves as a support for the free end A of the fuel line 26 within the line 21. The length of the burner or combustion chamber 5 may be reduced thereby to such an extent by a construction described hereinabove that it may terminate at the baffle plate 10 forming an annular cross section 28 which is left free by the baflle plate 10.

FIGURE 3 shows a further modification of the embodiment described in FIGURE 2 in that the main combustion air is not supplied to the combustion chamber 5 by means of an inlet spiral so as to have tangentially directed components but is supplied thereto in the axial direction by means of a tube 30. The rotary movement is imparted to the combustion air in that case by means of a ring of radially disposed guide vanes 31, as shown in FIGURE 6, which are arranged about the longitudinal axis 8 of the burner or combustion chamber at the inlet side 20 thereof and the hub 32 of which carries the supply line or pipe 33 for the additional air. The fuel supply line 26 is also supported in that case by means of an insert member 27 which may be constructed as described in connection with FIGURE 2 and which is arranged within the line 33.

FIGURE 4 illustrates the application of the present invention to a ram jet engine. To the air which is compressed dynamically in the intake nozzle 34 as a result of the flight speed is imparted again the rotary movement upon traversing or flowing through the guide vane screen 31, this rotary movement being about the longitudinal axis 8 of the combustion chamber 5. The ring-shaped or annular batfle plate 10 and the cylindrically-shaped guide member 23 for the additional air are provided in this embodiment with a guide portion 35 of preferably streamline shape for the outflowing combustion gases which are combined into a hollow body 36 of approximately mushroom shape. This hollow body 36 during operation reaches a relatively high temperature and thereby contributes in turn and in addition to the line 33' to the rapid evaporation of the supplied or injected fuel.

The other details as regards combustion and fuel sup ply within the chamber 5 are the same as those indicated in FIGURE 3. The part 36 of FIGURE 4, as well as the parts 10 and 23 in the embodiments described above, are secured or supported on the discharge line 33, 33 and 21 respectively by means of radially arranged sheet metal webs 38 which may be constructed in a manner similar to those described in connection with insert member 27 of FIGURES 2 and 3.

While I have shown and described several preferred embodiments in accordance with my invention, it is understood that the same is susceptible of many changes and modifications, and I intend to cover all such changes and modifications except as defined by the claims herein.

I claim:

1. A combustion chamber for combustion engines comprising means for supplying main combustion air to said combustion chamber at one end thereof including means for imparting to said main combustion air a spiral movement in the direction of movement thereof in said combustion chamber, baffle means including a plate located at the other end of said combustion chamber opposite said first-mentioned means to provide for partial return flow of said main combustion air and thereby produce an annular whirl superimposed on the spiral movement of said main combustion air, means for increasing the kinetic energy of said whirl including a pipe extending through said combustion chamber essentially centrally thereof over substantially the length of said chamber from said one end to said other end thereof and terminating adjacent said bafile means for supplying additional air to said combustion chamber, said baflle means including means for directing said additional air into said annular whirl in a direction opposite to the axial movement of the main combustion air therein, and means for injecting fuel into said pipe at a point adjacent said one end of said combustion chamber so as to allow admixture and preheating of said fuel and additional air prior to discharge thereof from said pipe.

2. A combustion chamber as defined in claim 1, wherein said fuel injecting means includes fuel discharge means arranged within said pipe and means for supporting said fuel discharge means within said pipe and for simultaneously imparting turbulent movement to said additional air.

3. A combustion chamber as defined in claim 1, wherein said baffle plate is ring-shaped, and wherein said means for directing said additional air in a direction opposite to the axial movement of the main combustion air includes a cylindrical guide part secured to said ring-shaped plate and a guide means for the ou tfiowing combustion gases.

4. A combustion chamber as defined in claim 3, wherein said fuel injecting means includes fuel discharge means arranged within said pipe and means for supporting said fuel discharge means within said pipe and for simultaneously imparting turbulent movement to said additional air.

5. A combustion chamber as defined in claim 1, wherein said means for imparting a spiral movement to said main combustion air is formed by a guide vane screen means which simultaneously serves to support said pipe adjacent said one end of the combustion chamber.

the combustion chamber, said inlet chamber having anend wall opposite said one end of the combustion chamber and a tangential inlet for the main combustion air, and wherein said pipe extends through said inlet chamber and said end wall.

References Cited in the file of this patent UNITED STATES PATENTS 2,164,225 Walker June 27, 1939 2,552,492 Nathan May 8, 1951 2,622,396 Clarke et al. Dec. 23, 1952 2,648,197 Keast et a1 Aug. 11, 1953 2,867,267 Nerad Jan. 6, 1959 2,935,840 Schoppe May 10, 1960 FOREIGN PATENTS 1,096,378 France Jan. 26, 1955 (Corresponding Australian Patent 204,504, June 16,

1955) 619,251 Great Britain Mar. 7, 1949 657,789 Great Britain Sept. 26, 1951

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