US3808802A

US3808802A - Vortex combustor

Info

Publication number: US3808802A
Application number: US00240699A
Authority: US
Inventors: Y Tanasawa
Original assignee: Toyota Central R&D Labs Inc
Current assignee: Toyota Central R&D Labs Inc
Priority date: 1971-04-01
Filing date: 1972-04-03
Publication date: 1974-05-07
Anticipated expiration: 1991-05-07
Also published as: JPS548890B1

Abstract

A vortex combustor of high efficiency, intensity and stability comprises a first cylindrical combustion chamber having an inlet means, a fuel supplying device and an igniting device, a second cylindrical combustion chamber having a throttled open part, and a connecting part having a throttled opening to connect the first combustion chamber and second combustion chamber, thereby to form respectively a forced vortex zone in the central region and a natural vortex zone in the outer region surrounding said central region of each of the first and second cylindrical combustion chambers with swirling air introduced through said inlet means, and to burn the mixture of air and fuel in the forced vortex zone of the first cylindrical combustion chamber and in the natural vortex zone of the second cylindrical combustion chamber.

Description

United States Patent 1 Tanasawa VORTEX COMBUSTOR [75] Inventor: Yasusi Tanasawa, Nagoya, Japan [73] Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho, Nagoya-shi, Japan [22] Filed: Apr. 3, 1972 [21] Appl. No.: 240,699

[30] Foreign Application Priority Data Apr. 1', 1971 Japan 46-20623 [52] US. Cl. 60/39.65, 60/3966, 60/3916 R, 60/39.72 R, 60/269, 60/271, 431/351 [51] Int. Cl. F02g 7/04 [58] Field of Search 60/3965, 39.23, 39.29, 60/3966, 39.72 R

[56] References Cited UNITED STATES [PATENTS 3,175,361 3/1965 Schirmer 60 3965 x 2,935,840 5/1960 Schoppe 60/3965 x 3,082,603 '3/1963 Hering...; 60/39.65 2,195,025 3/1940 CouzinetL... 60/39.65

1,069,243 8/1913. Fogler 60/39.65 ux 3,016,703 1 1962 LOI'CII 60/3965 [4 1 May 7,1974

2,601,000 6/1952 Nerad 60/3965 2,659,201 11/1953 Krejci 2,867,267 l/l959 Nerad 60/3965 X Primary Examiner-Clarence R. Gordon Attorney, Agent, or Firm0blon, Fisher, Spivak, Mc- Clelland & Maier [5 7] ABSTRACT the outer region surrounding said central region of each of the first and second cylindrical combustion chambers with swirling air introduced through said inlet means, and to burn the mixture of air and fuel in the forced vortex zone of the first cylindrical combustion chamber and in the natural vortex zone of the I second cylindrical combustion chamber.

20 Claims, 17 Drawing Figures PATENTEDIM 7 I974 SHEET 1 BF 3 T R A R l R P PRIOR ART PRIOR ART PRIOR ART :ATENTED MAY 7 i974 SHEET 2 OF 3 PATENTEDHAY 11914 v 3.808 802

sum

3 or 3 VORTEX COMBUSTOR BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vortex combustor which can be used for various purposes such as for home use, for industrial use, for gas turbines and for jet engines.

2. The Prior Art In case of the various conventional combustors,- because of their structure and severe operating condition, only in the narrow range of air-fuel ratio, the combustion efficiency and the combustion intensity (the weight of fuel which can be burned per unit time in the unit volume,or calorific value of the said fuel; kcal/m hr-atm) can be kept high in some degree. In the case of such combustors designed for gas turbines and for. jet engines, it is necessary to supply a large amount of air into the combustion chamber in proportion to its output. If this air flow increases, combustion flame does not spread to the whole inside wall of the combustion chamber, and the mixture of air and fuel is not burned with high intensity,so the combustion efficiency and the combustion intensity becomes low. While there have been many studies about vortex combustors, a satisfactory combustor for practical use has not yet been provided, mainly because of the fact that these studies haven't cleared up some of the important characteristics of vortex combustors.

SUMMARY or THE INVENTION Accordingly, it is an object of the present invention to provide a novel and useful vortex combustor. Another object of the present invention is to provide a vortex combustor having both high combustion efficiency and high combustion intensity.

Another object of the present invention is to provide a vortex combustor providing easy ignition and stable 'BRIEF DESCRIPTION OF THE DRAWINGS Various other objects,f eatures and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood from the following detailed description when considered in connection with the accompanying Drawings, wherein like reference numerals designate like or corresponding parts throughout the several Figures, and in which:

FIG.1 is a perspective view showing the construction of a conventional vortex combustor and its operating principle;

FIG. 2 is a vertical cross-sectional view of the vortex combustor of FIG.1;

FIG. 3 is a cross-sectional view showing the operating condition of the natural vortex in the combustion of a conventional vortex combustor;

FIG. 4 is the cross-sectional view showing the operating condition of the forced vortex in the combustion chamber of a conventional vortex combustor;

FIG. 5 is a partially cut-away perspective view showing the construction of a vortex combustor according to one embodiment of the present invention;

FIG. 6 is the vertical cross-sectional view of FIGS,

taken along the line VIVI thereof;

FIG. 7 is a cross-sectional view of FIG. 6 taken alon the line VIIVII thereof;

FIG. 8 is a cross sectional view of FIG. 6 along the line VIIIVIII thereof;

FIG. 9 is a view showing the first embodiment in which the vortex combustor of the present invention is applied to a gas turbine engine;

FIG. 10 is an explanatory view showing the spiral flowing condition in the combustion chamber of the vortex combustor of the present invention;

FIGS. llA-llF are explanatory views showing the progressive combustion conditions in the combustion chamber of the vortex combustor of the present invention; and

FIG. 12 is a view showing a second embodiment of the present invention in which the vortex combustion thereof is applied to another gas turbine engine.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS Under all operating conditions, the transition of the flame in the forced vortex zone near the center of the combustion chamber to the natural vortex formed between the outer surface of the forced vortex zone and the inner surface wall of the combustion chamber takes place very easily, and thus the mixture of air and fuel can be completely burned with high intensity. Thus, the combustion efficiency and the combustion intensity of the vortex combustorcan be greatly increased. Many problems in gas turbines and in jet enginges,such as the difficult ignition of the mixture of air and fuel, the blow-out of the flame,local overheating in the combustion chamber,and the complication of the structure, can accordingly now be resolved.

Hereafter,the various characteristics of a vortex combustor are closely explained.

As shown both in FIGS. 1 and 2, the cylindrical combustion chamber 1 of a conventional vortex combustor A is provided with an air inlet passage 2 having an air flow inlet port 3 which opens in such a manner that its axial direction coincides with the tangential direction of the inner peripheral surface of the chamber so that high pressure air being supplied into the combustion chamberl is given a swirling motion in a counterclockwise direction, the center of which is the axis of the cylindrical combustion chamber 1.

Near the center of the closed upper end wall 5 of the cylindrical combustionchamber 1, an ignition device 7 connected with an ignition energy source, now shown, is provided, with the ignition electrode 6 thereof being projected down into the combustion chamber 1. A fuel injection nozzle 9 connected to a fuel source, not shown, is also provided near the ignition device 7, and the injection hole 8 of nozzle 9 opens into the combustion chamber.

A lower wall part 10 opposing the closed wall 5 of the combustion chamber 1 has an exhaust hole 1 1 provided coaxially therein. In operation, compressed air is conducted tangentially into the combustion chamber 1, where it is mixed with fuel, and after being ignited and burned, the combustion gas is conducted out through the. exhaust hole 11.

Now, to explain the operation of the conventional vortex combustor A shown in FIGS. 1 and 2, the radius of the exhaust hole 11 is shown as r r is the radius of the combustion chamber 1, and h is the height of the combustion chamber.

When air of pressure P0 is supplied into the combustion chamber 1, the compressed air of specific weight 7 flows tangentially into the combustion chamber of radius r with a tangential velocity [14 from air inlet hole 3 of cross-sectional area S whereupon the compressed air swirls in the combustion chamber 1 and traces a spiral line 12. During this process, the pressure energy P/y is converted tethe velocity energy u /2 g, an d t h eg the tangential velocity u gradually, increases. In the case of an ideal fluid without viscosity, the law of the natural vortex u r ur holds,so that the tangential velocity u increases inversely as the radius r decreases.

When the radius r of spiral line 12 decreases,the radius r,. of exhaust hole l 1,the most part of the pressure energy of the compressed air is converted to swirling velocity energy,and the remaining part of the pressure energy is converted to velocity energy in the axial direction. The air flows out of the exhaust hole 11 with axial flow velocity V,., and when the radius r of the spiral line becomes equal to 1', which is smaller than radius r of the exhaust hole 11, the pressure of the compressed air in the chamber 1 becomes equal to the ambient pressure and pressure P0 is entirely converted to tangential velocity U ,and then all the swirling air flows out of the exhaust hole 11.

In this case, two kinds of vortex,namely forced vortex and natural vortex,occur in the combustion chamber 1. In the case of the former, as shown with dotted line in FlG.3, near the axial center of the combustion chamber 1, the tangential velocity decreases in linear proportion to the decrease of the radius. Namely,there is a tendency for that velocity gradient du/dr to become constant,and the pressure thereof is higher on the outer side and lower on the inner side because of a centrifugal force effect, and thus,the forced vortex zone E is formed. On the other hand, in the case of the latter, as shown in FIG. 4, between the outer side of the forced vortex E and the inner surface wall 14 of the combustion chamber 1, the tangential velocity increases with decrease of the radius according to the law of natural vortex,where m7 constant, and pressure along the radius is higher on the outer side and lower on the inner side, and thus a natural vortex zone F is formed.

Various features clarified by these experiments and analysis about vortex combustors are therefore as follows.

1. Easy ignition of the mixture of air and fuel can be carried out in the forced vortex zone of the combustion chamber. 1

The forced vortex E rotates without producing relative movement in its inner side as if the forced vortex is in the condition of a columnar solid rod,and the tangential velocity at the axial center of the forced vortex E becomes zero. The fuel is then injected into the forced vortex E in its radial direction from the fuel injection nozzle 9 provided near the axial center of the combustion chamber 1, and by means of discharging an electric spark from the ignition device 7, fuel is easily ignited silently. This is caused by the fact that the relative velocity between the fuel and the air is nearly zero in the forced vortex,which is the essential condition for easy ignition.

In the case of this vortex combustor A, the circumference of the forced vortex E is surrounded not by the solid wall but by the natural vortex F,so explosive noise does not occur.

2. It is possible to cause local combustion in the forced vortex E zone of the combustion chamber,and stable combustion without the blowout of the flame can be carried out in a wide range of the air-fuel ratio.

The flame appearing in the forced vortex E is formed as a rotating columnar shape, and this rotating flame is very stable as if it exists in a rotating cylinder having an inside wall surface which corresponds to the boundary surface'lS separating the forced vortex E-from the natural vortex F.

When only a small amount of fuel is supplied into the combustion chamber of the ,vortex combustor A, a rotating columnar flame occurs in the forced vortex E having a short length in its axial direction,and its length gradually increases as the fuel flow increases, and it burns to reach to the exhaust hole of the combustion chamber 1. Therefore, in the case of this type of combustion, the combustion operation is completed within the forced vortex zone and in this condition, the'combustion chamber is partially used,sothe high intensity combustion is not carried out.

When the fuel being supplied is increased even. more,the rotating columnar flame spreads into the zone of the natural vortex F surrounding the forced vortex v As there exists a large tangential velocity gradient du/dx in the natural vortex, perfect mixing of the air and the fuel takes place, resulting in a violent combustion. But the transition of the rotating columnar flame in the forced vortex to the violent swirling flame in the natural vortex can be obtained when the design of the combustor is suitable, that is,the diameter of the exhaust hole 11- must be chosen rather larger and the cross-sectional area of the air inlet hole 3 must be suitably smaller.

3. Combustion gas is recirculated by the reverse'flow produced in the forced vortex,and it becomes able'to operate with low exhaust emissions.

Thus, the forced vortex E rotates without relative movement taking place between the fuel and the air- ,and the pressure in the forced vortex E becomes higher on its outer side and lower in its central part because of the centrifugal force effect. Also, the pressure becomes equal to the ambient pressure at the part of the outer circumference radius r of the forced vortex E, and pressure in the central part becomes lower than ambient pressure,and the ambient air is introduced within the central part of the forced vortex E through the exhaust hole 11.

4. As the fuel stays for a long period of time in the combustion chamber, due to the swirling motion of the compressed air and fuel,the combustion efficiency can be increased.

5. Because within the zone of the natural vortex,fuel and air are burned in a condition of perfect mixing,the fuel is completely burned at a high temperature,- whereby combustion efficiency and combustion intensity can be increased.

When compressed air is supplied from the air inlet hole 3, which opens tangentially along the inner peripheral surface 4 of the combustion chamber 1, and rotates in the combustion chamber as shown in FIG. l,its pressure energy is gradually converted to velocity energy to increase the tangential velocity u. As the radius r of the spiral line of air movement becomes smaller,the rotating angular velocity w u/r becomes larger.

The rotating angular velocity at the point of any radius r is w and that at an adjacent point of radius r +Ar is w +Aw. In this case, A w has a minus value, since increasing radius results in decreasing velocity, and because of this difference A w, a slip phenomenon occurs. The perfect mixing of air and fuel is promoted by distortion due to this slip phenomenon. Namely, in the natural vortex,the velocity gradient du/dr is very large near the forced vortex E because the tangential velocity u varies greatly in this zone,as shown in FIG.3. When a fuel lump or solid piece of fuel 16 is supplied into the natural vortex F,the fuel lump 16 is subjected to a shearing force due to slip caused by the difference of the rotating angular velocity at the outer part of the lump where the radius r is large and that at the inner part where the radius r is small. The fuel lump is thus atomized into very small pieces and is entirely mixed with air to a perfect mixing condition. On the contrary,in the forced vortex E, as shown in FIG. 3, the fuel lump 16 is placed where the velocity gradient du/dr is constant and slip does not occur, as if the lump is placed in a rotating solid rod,and therefore,the fuel lump rotates by itself and does not receive any shearing force,so that the fuel lump 16 is not atomized into smal pieces.

Therefore, if the air-fuel ratio is correct or stoichiometric, for example, the ratio of the air flow rate wa to the hydrocarbon fuel flow rate wf is chosen as :1 by weight,the mixture burns'completely in the condition of perfect mixing in the natural vortex F in which slip phenomenon occurs.

When the difference between rotating angular velocity of the forced vortex E and the natural vortex F at the boundary surface becomes larger than a certain constant value,flame in the forced vortex E is blown out at the boundary surface,and the flame is not able to be transferred into the natural vortex F. This face was also recognized by the experiments.

This transition is done more easilyas the ratio D /D between the inner diameter D, of the combustion chamber 1 and the diameter D of the exhaust hole 11 increases,and as the ratio Si/D D between the crosssectional area Si of the air inlet hole 3 and D,D

- VPo, so that the transition of flame from the forced vortex E into the natural vortex F becomes difficult,if the ratio D /D of the diameter of the exhaust hole 11 to the inner diameter of the combustion chamber 1 decreases and the air flow rate w increases.

In case the transition of combustion from the forced vortex E into the natural vortex F is difficult, a sheath of blue flame occurs around the outer surface of the rotating columnar flame,and the flame goes out of the exhaust hole 11 of the combustion chamber 1. In this case,even if the fuel is increased,the flame only goes out of the combustion chamber 1, and combustion is not transferred to the natural vortex zone.

It is known from the above description that combustion must be operated in the forced vortex in the case where a weak mixture of air and fuel has a large air-tofuel ratio, and that combustion must be operated in the natural vortex in the case of a correct mixture of air and fuel, where the air-to-fuel ratio is nearly equal to the theoretical ratio, in order to obtain a combustor which is operative over a wide range of mixture ratios wa/wf.

From the studies of the conventional vortex combustors, it was observed that fuel supplied from the axial center of the combustion chamber 1 is always burned to produce a rotating columnar flame in the forced vortex, but it was also observed that the combustion is not 1 automatically transferred into the natural vortex zone. When fuel flow increases while air flow being supplied tangentially into the combustion chamber 1 is kept v still further, the rotating columnar yellow flame separates from the fuel injector and becomes surrounded by blue flame extending in the axial direction, and at last, a thin twisted columnar yellow flame occurs within the combustion chamber 1 and' a flat disc type flame of mixed color of blue and yellow exists from the exhaust hole 11 of the combustion chamber 1, and becomes a stable in this condition. These rotating columnar flames are always confined in the forced vortex and do not invade the natural vortex zone.

Taking into consideration the various points described above, various experiments have been conducted to clarify these observed characteristics, and from such studies the vortex combustor of the present invention having structure of various superior characteristics has been provided.

The vortex combustor of the present invention thus comprises a first combustion unit having a cylindrical wall and an end wall on one end of the cylindrical wall thereof for forming a first combustion chamber, a second combustion unit having a cylindrical wall and an end wall-on one end of its cylindrical wall for forming a second combustion chamber, a connecting part having a throttled opening for integrally connecting the other end of the two combustion units, at least one inlet means provided to the first combustion unit for introducing gas therethrough tangentially into the first combustion chamber, a fuel supplying device and an igniting device provided in the first combustion unit opposite the connecting part and positioned near the central In the vortex combustor of the present invention, the rotating columnar combustion of yellow flame is carried out in the forced vortex zone in the first combustion chamber, and is projected from the connecting part into the second combustion chamber, and immediately after this process, it spreads into the natural vortex zone of the second combustion. chamber, where it is transformed into a circumferential swirling combustion automatically and rapidly so that stable and violent combustion can be carried out, having very high com bustion efficiency and combustion intensity in a wide range of air-fuel ratio. Thus, difficulty of ignition of the mixture of air and fuel, blow-out of combustion flame, local overheating in the combustion chamber, and the like which were the defects encountered in the various conventional combustors, can be solved.

Now, the structure of the vortex combustor of the present invention'will be explained in detail according to certain embodiments thereof, and the combustion state realized by the combustion in the forced vortex zone in the combustion chamber being transferred to the natural vortex zone automatically and rapidly, will also be explained.

As shown in FIGS. to 8, a first outer cylindrical member 18 and a second outer cylindrical member 19 are axially connected end-to-end to form an outer cylinder 17. The diameters of these two cylinders are usually equal, while the respective lengths thereof in their axial directions are different from one another. On the outer circumferential edges 24 of the

open parts

20, 21 and 22, 23, which open in the axial direction of the first and the second outer

cylindrical members

18 and 19, respectively, integral flanges 26 being perforated with a plurality of attaching holes 25 arranged in a circular array are provided for connection to other parts. On the end surfaces of open parts '20 and 23 of the first and second outer

cylindrical members

18 and 19, respectively, disc

type end plates

27 and 28 are secured by suitable means, such as bolts 29, nuts, or the like, through attaching holes 25' perforated in the outer circumferential edges of the

end plates

27 and 28 which correspond to the attaching holes 25 in the end flanges 26. On the other hand, an annular plate type throttle plate 31, having a connecting hole 30 coaxially with the outer cylinder 17, is fixed by fixing members 29 through attaching holes in its circumferential edge corresponding to attaching holes 25 at the circumferential edge of the outer cylinder, being disposed in a vertical plane with respect to the axial direction of the outer cylinder between the end surface of the open part 21 of the first outer cylindrical member 18 and the end surface of the open part 22 of the second outer cylindrical member 19, which are disposed face-to-face mutually.

An inner cylinder 32 is coaxially inserted into the outer cylinder 17. One end of the cylinder 32 is closed, and the other end is open. The outer diameter of the inner cylinder 32 is made smaller than the inner diameter of the outer cylinder 17 and also is made smaller than the inner diameter of the connecting hole 30 of the throttle plate 31. Between the outer cylinder 17 and the inner cylinder 32, on opposite sides of the throttle plate 31, there are formed an annular chamber 33 and a mixing chamber 34, the volume of the mixing chamber 34 being made smaller than that of the annular chamber 33.

The annular chamber 33 and the mixing chamber 34 are mutually connected by the connecting hole 30 which provides an annular passage between the throttle plate 31 and the inner cylinder 32. An inlet hole 37 is provided in the wall 35 of cylindrical member 18 in such a manner that the axial direction thereof coincides with the tangential direction of the inner peripheral. surface 33' of the annular chamber 33, so that compressed air may be conducted into the annular chamber 33 through a supplying passage 36 connected with a compressed air supply. in the outer cylinder wall part 38forming the mixing chamber 34, an outlet hole 40 is provided in such a manner that the axial direction thereof coincides with the tangential direction of the inner peripheral surface 34 of the mixing chamber 34, so that combustion gas, ignited and burned in the inner cylinder 32, may be exhausted out through an exhaust passage 39 connecting with the mixing chamber 34. The outer side of the closed end 41 of the inner cylinder 32 is attached to one end of a sealed annular bel lows 44 which is fixed to the open end 43 of the outer cylinder 18 side of an open hole 42 perforated in the central part of the end plate 27, to permit stretching of the inner cylinder in its axial direction due to heat expansion, and to prevent leakage from the annular chamber 33. A plurality of radial supporting members 46 are attached integrally to the outer cylinder 17 for supporting the inner cylinder 32 in coaxial relation with the outer cylinder 17, evenif the inner cylinder moves in its axial direction.

In the inner cylinder 32, there are formed a first combustion chamber 49 and a second combustion chamber 50 axially aligned therewith, and the'volume of chamber 50 is made to be larger than that of chamber 49. These chambers are divided by a first connecting part 48 having an inner diameter smaller than that of the inner diameter of the inner cylinder 32. A plurality of connecting holes 53 are provided in the circumferential side wall 51 of the first combustion chamber 49 for connecting the inside part of the first combustion chamber 49 with the annular chamber 33 the'reabout, the holes being made to openthereinto so that their axial direction coincides with the tangential direction of the inner circumferential circle 52 of the first combustion chamber 49. At the axial center of side wall 54 of the closed end 41 of the first combustion chamber 49, the ignition device 7 is provided being connected with an ignition energy source. The ignition part 6 projects into the first combustion chamber 49, and the fuel injection nozzle 9 is disposed along side. This valve 9 connects with the fuel supply source, not shown, and its injection hole 8 is made open so that its axial direction is corresponding to the axial direction of the first combustion chamber 49. The second combustion chamber 50 connecting with the first combustion chamber 49 through the connecting part 48 at one end, has an open end 47 at its other end which connects with the mixing chamber 34 through a throttled open part 55 having an end plate 551 thereon. The part 55 is formed to have an inner diameter smaller than that of inner cylinder 32 while being coaxial therewith, while at the same time being larger than that of the first connecting part 48. An annular cover plate 57 of head cut conical shape is provided in the end plate 28 between the open port 47 of the second combustion chamber 50 case, high efficiency and high intensity combustion are t in demand and a great amount of air flow is necessary. Hereafter, the present invention will be explained with respect to an embodiment designed for gas turbines in automobiles.

A gas turbine G foran automobile includes an air compressor C, the heat exchanger H, a vortex combustor A, and a turbine T. The air compressor C comprises an impeller vane 61 and a diffuser vane 63. The impeller vane 61 is mounted on an axle 60 rotatably driven by a generator or a starting motor through a driving gear, not shown, for introducing high temperature air. On the other hand, the diffuser vane 63 is attached to a side wall 62 of the compressor C, with an upper flow' side 64 of the compressor C being connected with an air inlet opening 65 for introducing air into the compressor C. The lower flow side 66 of the air compressor C is connected with a compressed air conducting passage 67 of the heat exchanger H in order to introduce compressed air from the air compressor C to the heat exchanger H. In the heat exchanger H, the air of low temperature and high pressure from the air compressor C receives heat radiation of the combustion gas of high temperature and low pressure, and is converted to air of high temperature and high pressure in the grid type compressed air inlet passage 67. Combustion gasis introduced through passages 68, having first been ignited and burned in the vortex combustor A, and having carried out expansion work in the turbine T. The passages 67 and 68 are isolated from each other in the heat exchanger H, and the outlet side 69 of the combustion gas-introducing passage 68 is connected to the outside atmosphere. Thus, in the case of the vortex combustor A the supply passage 36 thereof is connected to the exhaust side 70 of the compressed air-introducing passage 67 of the heat exchanger H through an intake conduit 71, and the exhaust passage 39 thereof is connected with an inlet openng 72 of the turbine T. The turbine T has a casing 75 provided with a supply passage part 73 whichconnects with the exhaust passage 39 of the vortex combustor A and an exhaust gas passage 74 through which the combustion gas is introduced to the grid type combustion gas-introducing pas- 1 sage 68 of heat exchanger H. Also, the turbine T has a turbine wheel 76 for the compressor provided on the axle 60 such that it is rotatable as a unit with the impeller vane 61 of the air compressor C, being disposed in mutually spaced coaxial relation, and has a nozzle 77 for the turbine which is attached to the casing 75 opposite the turbine 76.

A power turbine 81 is disposed coaxially with the compressing turbine 76 in the casing 75 and a variable inlet nozzle 82 of increasing cross-section for the power turbine is disposed therebetween. A driving wheel axis 78 being parallel with that of the turbine 76 is connected to the turbine 81 via a set of reduction gears 79 and 80.

The operation of the gas turbine to which the vortex combustor of the present invention is applied will now be explained. When the gas turbine G is operating, air is introduced into the air compressor C through the air inlet hole 65, and is compressed by the impeller vane 61 and diffuser vane 63 thereof. The air compressed by the diffuser vane is introduced into the grid typecompressed air inlet passage 67 of the heat exchanger H, where it becomes air of high temperature and high pressure, by receiving heat radiation from the combustion gas being passed in the combustion gasintroducing passage 68 which is provided adjacent the passage 67, and then it is introduced into the annular chamber 33 of the vortex combustor A,, through the outlet 70, conduit 71 and passage 36, and finally the opening 37 of the vortex combustor A,.

Thus, compressed air of high temperature is introduced into the annular chamber 33 and is given a swirl ing movement therein, the center of which corresponds to the central axis of the annular chamber 33, by means of the introducing hole 37 which opens into the chamber in such a manner that the axial direction thereof coincides with the tangential direction of the inner peripheral surface 33' of the annular chamber 33.

The swirling air of high temperature and high pressure flows between the inner side wall 35 of the outer cylinder 17 and the outer'side wall 45 of the inner cylinder 32 in the annular chamber 33, toward the other end of the chamber, and is throttled by the connecting hole 30 of the throttling plate 31 between the annular chamber 33 and the mixing chamber 34, then being introduced into the mixing chamber 34. Thus, the swirling compressed air of high temperature in the annular chamber 33 is caused to have a pressure drop AP compared with the air in chamber 34 by means of the throttling operation of the throttle plate 31.

As shown in FIG. 10, the air also flows into the first combustion chamber 49 along the tangential direction of the inner peripheral surface 52 thereoffrom the plural connecting holes 53 of the first combustion chamber 49 connected with the annular chamber 33, whereby the air therein is given a swirling motion, the center of which corresponds to the central axis of the first combustion chamber 49. The compressed air of pressure P0 being supplied to the first combustion chamber 49 thus traces a spiral line, and is projected into the second combustion chamber 50 from the first connecting part 48 in the direction composing the tangential velocity Ue and the axial velocity Ve. In this case, in the first combustion chamber 49 the forcedside wall 52 of the first combustion chamber 49. The

pressure energy of the-swirling air flow forming the natural vortex F is gradually converted to velocity energy during its swirling movement, and according to the law of the natural vortex ur=constant, tangential veloc ity u increases in inverse proportion to the radius of the spiral line r, and finally, when the radius decreases to r which is smaller than the radius r of the connecting part 48, the pressure becomes equal to that of the mixing chamber, and so, the pressure drop AP is entirely converted to tangential velocity Uc.

Therefore, the rotating air column, called the vortex eye, is formed near the axial center of the first combustion chamber 49, and the air in the vortex eye becomes the forced vortex which rotates with little relative movement, and there occurs the phenomenon that in the outer circumference, pressure is high, and in the central part, pressure is low, due to the centrifugal force effect. The radius of the forced vortex E is r,., and its pressure becomes lower than that of the outer air pressure, and then there occurs the phenomenon that the outer air is introduced into the central part in the vortex eye by a reverse recirculating flow. The combustion gas, or exhaust gas, is introduced into the central part of the forced vortex E from the second combustion chamber 50 through the first connecting part 48. By means of the fuel injection nozzle 9 and the ignition device 7 provided near the axial center of the side wall 54 of the closed part 41 of the first combustion chamber 49, fuel is injected along the axial direction of the first combustion chamber 49, and an electric spark is generated periodically in the central part of the rotating air column of the forced vortex E swirling around the central axis of the first combustion chamber 49. In the forced vortex E, a fuel lump is placed in the condition of the constant velocity gradient du/dr, so that it rotates by itself without mutual relative movement between the fuel and air. The fuel lump is atomized into'small pieces by means of a shearing force, and gradually mixes with the air in the rotating air column of the forced vortex E, and rotates in the forced vortex E in the condition that its relative velocity with the, air therein is almost zero. In this situation, the fuel mixture is easily ignited and burned by the electric spark of the ignition device 7. The flame generated by the electric spark has little velocity in the axial direction, but has substantial velocity in the tangential direction, and it rotates such that there is substantially no mutual relative movement between the fuel and air. Thus, the flame does not blow out unlike the case of the various conventional combustors in which the combustion is carried out in the supplied air flow, and because the natural vortex F surrounds the forced vortex E at the time fuel is ignited and thereafter, an explosive noise does not occur, since it is much as if it is surrounded by a solid wall. The combustion in the rotating air column of the forced vortex E is very stable and still, being a local rotating column combustion of yellow flame. According to the experiments, this local combustion is very stable without blowout even if the swirling velocity of the natural vortex F around the forced vortex E is made larger, and the rotation speed of the forced vortex E ismade higher.

The combustion condition of the vortex combustor is shown in FIGS. llA-llF. Namely, when a little fuel flow is supplied into the first combustion chamber 49, a short rotating columnar flame appears in the forced vortex E, as shown in FIG. 11A. As fuel flow increases, as shown in FIG. 1 1B, the length of the rotating columnar flame in the axial direction increases to reach to the first connecting part 48 of the first combustion chamber 49, and then the combustion flame spreads into the second combustion chamber 50.

Next, as shown in FIGS. 11C and 11D, the rotating columnar flame spreads radially as well as axially in the second combustion chamber 50, in the zone of the natural vortex F surrounding the forced vortex E. The fuel is atomized to thin small pieces and mixes perfectly with the air in the swirling flow of large velocity gradient in the natural vortex F, for in this flow the mixture is subject to the shearing force occuring because of the difference of the rotating angular velocity along the radius, thus a slip characteristic.

The mixture of air and fuel in the condition of molecule mixture is transmitted by the combustion flame from the first combustion chamber 49, and it can be burned at the highest temperature and with high intensity near the inner circumferential wall of the second combustion chamber 50. Thus, both high combustion efficiency and high combustion intensity can be realized. As shown in FIGS. 11E and 11F, the rotating columnar flame, burning in the zone of the forced vortex E of the first combustion chamber 49, projects into the second combustion chamber 50 from the first connecting part 48, and immediately after spreads in the zone of the natural vortex F of the second combustion chamber 50, both axially and radially, and thus is converted to swirling combustion in the circumferential part so that the combustion can be fully carried out, and since the combustion flame reaches the inner side wall surface of the second combustion chamber 50, the side wall of the second combustion chamber 50 is heated to a high temperature by the combustion therein. In the vortex combustor of the present invention, the cylinder 32 providing

combustion chambers

49 and 50 is disposed in radially spaced relation within the outer cylinder l7, and a swirling air flow is introduced between the inner side wall of the outer cylinder 17 and the outer side wall of the inner cylinder 32, which define the annular space 33. The side wall of the second combustion chamber- 50 is therefore cooled by this swirling air, so that the temperature of the side wall can be held down to prevent damage thereto from overheating. Unlikethe various conventional combustors, it is unnecessary to provide a limitation on the combustion conditions such as to maintain a determined gap between the inner side wall surface and the combustion flame in order to prevent overheating damage of the side wall of the combustion chamber. Therefore, the second combustion chamber 50 can be used with greater efficiency, and the swirling combustion in the circumferential part thereof can be carried out such that the combustion flame can reach the inner side wall of the second combustion chamber at its highest temperature. In this case, the high temperature combustion gas is introduced into the mixing chamber 34 from the open port 47 in the second connecting part 55 of the second combustion chamber 50. The combustion gas is then recycled by reverse flow in the second combustion chamber 50 as the pressure in the central part of the zone of the forced vorted E becomes low because of the cover plate 56 disposed opposite port 47.

Thus, the flame temperature can be lowered and also the generation of harmful nitrogen oxide gascan be markedly prevented because the invasion of air from mixing chamber 34 into the second combustion chamber 50 can be blocked.-

The swirling gas discharged from the open port 47 of the second combustion chamber strikes against the cover plate 56 and has its flow direction radially turned. I

During the swirling flow between the cover plate 56 and the end plate 551 of the throttled connecting part 55, the tangential velocity of exhaust gas gradually decreases and the pressure increases by the diffuser action. Thus the pressure loss in the combustor due to the swirling flow is somewhat recovered.

The exhaust gas mixes with the air in the mixing chamber 34 being passed thereinto through the throttle plate 31. The swirling flow of the mixing air passed through the throttle plate 31 helps to keep the temperature distribution in the mixing chamber uniform. Moreover, the cover plate 56 is heated to a high temperature because its surface facing the port 47 is directly contacted by the flowing combustion gas, but since the pposite surface of the cover plate 56 is exposed to the outer atmospheric air.directly, its temperature is prevented from rising too significantly..Also, because its contact area with outer atmosphere is quite large because of its configuration, the cooling effect of the covered part 57 to prevent overheating caused by the combustion gas, and therefore damage thereto, is greatly enhanced. I

i The combustion gas is cooled to a certain temperature after the mixing operation in the mixing chamber 34, and the gas is conducted out tangentially along the inner peripheral surface 34' of the mixing chamber 34 from the outlet hole 40 which is made open in such a manner that its axial direction coincides with the tangential direction of the inner peripheral surface 34' of the mixing chamber 34. The combustion gas then flows into the turbine nozzle 77 for the compressor of the turbine T and into the variable nozzle 82 for output therefrom.

Expansion work is carried out in the turbine T, by means of the energy of the combustion gas, and thus the turbine 76 for the compressor and the power turbine 81 are rotatably driven. After the expansion work in the turbine T has been completed, the combustion gas is conducted through the grid type gas conducting passage 68 of the heat exchanger H, for pre-heating the compressed air which passes through the compressed air conducting passage 67 isolatedly disposed in the heat exchanger from the combustion gas conducting passage 68, and then the combustion gas is exhausted from the exhaust hole 69 of the combustion gas conducting passage 68 through an exhaust pipe, not shown.

Furthermore, in a vortex combustor constructed according to the present invention, preferably values can be selected according to the various objects and uses.

These values are as follows:

1. The ratio of the diameter D of the first connecting part. 48 to the inner diameter D, of the first combustion chamber 49, D lD 2. The ratio of the cross-sectional area S; of the connecting hole of the first combustion chamber to the product of the inner diameter D of the first combustion chamber and the diameter D of the first connecting part, S,/D D

' 3. The values of D and D in a relation of D, D where D, is the diameter of the open port 47 of the second combustion chamber 50 and D is the diameter of the connecting part 48 of the first combustion chamber; and

4. The ratio of the diameter D, of the open part of the second combustion chamber 50 to the inner diameter D of the second combustion chamber, D /D Namely by our experiments and analysis with the vortex combustors of the present invention, it was found that D /D should be less than or equal to 0.6, and S /D D should be less than 0. l

Thus, the rotating columnar flame can be positively provided in the first combustion chamber 49 in the zone of the forced vortex where the pressure loss is very small, because of the constant velocity gradient therein. On the contrary, in the case of the second com-.

bustion chamber 50, it was found that the diameter D, of the open port 47 should be made to be larger than the diameter D of the connecting part 48 of the first combustion chamber 49, and the ratio between the inner diameter D of the second combustion chamber 50 and the diameter D of its open port 47,- D /D should roughly be taken to be less than 0.8. Thus, the rotating columnar flame burning in the zone of the forced vortex E in the first combustion chamber 49 is projected into the second combustion chamber 50 from the first connecting part 48, where the flame immediately spreads radially into the zone of the natural vortex F in the second combustion chamber 50, and can then be transmitted to the circumferential and swirling combustion state automatically and rapidly; In the case of the combustors of the present embodiment, the conducting hole is not provided at the second combustion chamber to conduct air for combustion, but when a connecting hole of sectional area S is provided, in other embodiments, the condition S IDQD S ,/D,D must be satisfied.

The vortex combustor of the present invention has various superior effects which will be described hereinafter: I

l. The fuel injection nozzle and the ignition, device are provided closely to one another in the region of the forced vortex E near the centralaxis of the first combustion chamber 49 and the fuel is supplied in a mist condition in a wide angle being directed in the axial direction of the first combustion chamber. The fuel is easily ignited by the electric spark without any explosive noise, even if the natural vortex F surrounding the forced vortex E rotates'very rapidly. If the combustion flame is blown out by some factor, the fuel can be ignited very easily again.

2. Since the fuel stays for a long period of time in the first and the second combustion chambers because of the swirling flow pattern, the combustion efficie'ncy becomes as high as nearly percent, whether the combustion condition in the combustion chamber is the yellow flame combustion or the blue flame combustion.

3. The fuel and air are mixed together perfectly in the zone of the natural vortex F in the-second combustion chamber 50, so the combustion-intensity becomes large when the blue flame combustion spreads into the entire second combustion chamber.

4. From the rotating columnar combustion in the forced vortex zone in the first combustion chamber 49, to the high. intensity blue flame combustion in the zone in the second combustion chamber of the natural vortex, complete combustion is carried out in a continuous and stable condition, so an air-fuel ratio of very wide range, Wa/Wf E l5-300, which is wider than that of the usual combustors, Wa/ Wf E 17-23 is permitted.

5. The cover plate 56 is disposed between the open port 47' of the second combustion chamber 50 and the outlet hole 40 of the mixing chamber 34. The cover plate 56 part also is near and opposite to the open port 47. Thus, the combustion gas is exnitrogen-oxide gas is prevented from occurring.

The volume of re-circulating gas depends on the ratio D,/D of the diameter D, of the open port to the inner diameter D; of the second combustion chamber and it increases as the ratio D,/D becomes larger. Generally speaking, if complete combustion is carried out in the combustors of high efficiency, no harmful gas such as hydrocarbon and carbon monoxide exists, but when the combustion flame temperatureis high, nitrogen oxides will be produced. As complete combustion also takes place in the vortex combustor of the present invention, no hydrocarbon and no carbon monoxide exists. But, the likely production of nitrogen oxides also disappears because of the recirculation of the exhaust gas, by which the flame temperature is lowered to about l,600 C.

6. Moreover, a high intensity combustion is carried out in the combustion chamber of the vortex combustor, so that all kind of fuels, such as gas fuel,

gasoline, lamp oil, light oil, heavy oil and the like, can be equally burned in a wide range of air-fuel ratio.

7. As shown in FIGS. 1 1Al lC, in the forced vortex of the first combustion chamber, local combustion is carried out using a central combustion chamber, without directly contacting the outside wall of the combustion chamber. Therefore, high temperature combustion from 1,500 to 3,000 C can be carried out by mixing oxygen in fuel for practical use. In this case, heat caused by heat radiation at the side walls ofthe first and the second

combustion chambe rs

49 and 50, is cooled by means of the swirling air flow flowing into the

annular chambers

33 and 34 in the outer cylinder 17 surrounding the inner cylinder. Therefore, the side wall surface of the combustion chamber is not damaged by overheat- The combustion flame in the first and the

second combustion chambers

49 and 50 of the vortex combustor rotates rapidly, so the temperature distribution becomes uniform along the circular direction of each combustion chamber, and unlike the case of the usual combustors, local overheating does not occur.

9. The combustion gas is discharged from the open 10. In the case of the conventional combustors, a first air and a second air are supplied from many air holes, so various experience and many experiments are necessary to determine the number, the diamev 16 ter, and the arrangement of the air holes, but the vortex combustors of the present invention can be easily designed;

While in the first embodiment described in detail above, the vortex combustor of the present invention is shown being applied as separate apparatus from the gas turbine engine itself for automobiles, the present invention is not limited to this arrangement and type of turbine for a gas turbine engine, but it may be made for any type. For example, the present combustor can be applied to small and simple gas turbine engines-for aviation. The combustor itself is combined into an engine in one body, and the length in the axial direction of the combustor is made short. in this case, the vortex combustor of the present invention can be applied, as shown in FIG. 12, by varying the design and size of various components of the vortex combustor from those of the first embodiment.

Now referring to FIG. 12, a second embodiment of the present invention will be explained.

' A gas turbine engine 6,, is composed of an air compressor C, a vortex combustor A, and a turbine T, all

being disposed respectively in coaxial relation in an engine casing of circular cylindrical design. The air compressor C and the turbine T are respectively fixed to a rotating axle 86 for rotation therewith as a unit. An annular outer cylinder 170, of the vortex combustor A of which both ends are closed, is provided between the air-compressor C and the turbine T, and both side circumferential walls thereof are supported by'the engine casing 85, while the inner circumferential wall thereof is axially supported by the rotating axle 86. An annular inner cylinder 320, one end thereof being closed and the other end being open, is coaxially disposed within the outer cylinder 170. Between the inner side wall of the outer cylinder and the outer side wall of the inner cylinder 320, a throttled plate 310 is provided, and an annular chamber 330 and a mixing chamber 340, being connected with each other, are formed by the throttled plate 310. An annular conducting hole 370 is open at a side wall part 350 of the outer cylinder 170 forming the annular chamber 330. The hole 370 connects with the air compressor C and air is conducted through hole 370 along a tangential direc: tion of the inner circumferential circle of the annular chamber. An annular exhaust hole 400 opens at the side wall part of the outer cylinder 170 forming the mixing chamber 340. The combustion gas is thus conducted out of the inner cylinder 320 to the mixing chamber 340, and then is exhausted from the mixing chamber 340 to the turbine T through the hole 400.

The annular inner cylinder 320 is divided into a first combustion chamber 490 and a 'second combustion chamber 500 by an annular connecting part 480 which is disposed between a closed end part 410 and an open end part 470 thereof. The first combustion chamber 490 is composed of a pre-combustion section 87 and a combustion section 88, the pre-combustion section 87 and the combustion section 88 being mutually connected by means of a connecting hole 530. This connecting hole 530 conducts the combustion gas from the pre-combustion section 87 along a tangential direction of the inner circumferential circle of the combustion section 88, with one end being closed while the other end is open.

The ignition device 7 and the fuel injection nozzle 9 of this embodiment are disposed side-by-side near the axial center of the closed end of the pre-combustion section 87. The ignition device.7 is connected with an ignition energy source, and its ignition part projects into the inside of pre-combustion section 87. The fuel injection nozzle 9 connects with a fuel supply source, and its jet hole 8 opens toward the pre-combustion section 87,. A plurality of air inlet holes 3 are provided in the pre-combustion section 87, the insideof the air inlet holes 3 connecting with the annular chamber 330 and conducting air along a tangential direction of the inner circumferential circle of the pre-combustion section 87. On the other hand, an annular open port 470 is provided in the second combustion chamber 500, which connects with the mixing chamber 340, and its outer diameter is the outer circumferential edge of the inner cylinder 320. Also, a closed wall 90 is formed in the second combustion chamber 500 in the same plane with the annular open port 470, so that the closed wall 90 covers the area near the axial center of the second combustion chamber 500, and at the same time, a second annular connecting part 550 is formed near the said annular open port 470.

According to this second embodiment of the present invention, as described above, near the central part of the rotating air column of the forced vortex in the precombustion section 87 of the first combustion chamber 490, fuel from the fuel jet injection nozzle 9 is mixed with swirling air flow and it is ignited and burned by generating periodically an electric spark with the ignition device 7. Then, a rotating columnar flame in the region of the forced vortex is jetted into the combustion section 88 of the first combustion chamber 490 through the connecting hole 530 At this time, the flame is given the swirling movement along a tangential direction of the inner circumferential circle of the combustion section 88. Immediately after this process, the rotating columnar combustion carried out in the zone of the forced vortex E in the combustion section 88 is jetted into the second combustion chamber 500 from the first annular connecting part 480, and then is widened in the zone of the natural vortex F in the second combustion chamber 500, where it is converted to the circumferential swirling combustion automatically and rapidly. Thus, high intensity combustion can be carried out at the highest temperature. The inner circumferential wall of the second combustion chamber 500 -is used as the reaction surface. The combustion efficiency and the combustion intensity in this case, are very high, and therefore, the apparatus of the second embodiment has a good effect, essentially the same as the case of the first embodiment. Moreover, the vortex combustor itself can be constructed to be of small size, and thus a compact and simplified gas turbine engine can be obtained.

In the first and the second embodiments of the present invention, the inlet holes and the connecting holes are made to open tangentially along the inner circumferential circle of the annular chamber, or the first combustion chamber, so that air for combustion, to be supplied into the annular chamber, or the first combustion chamber, of the vortex combustor, is given a swirling movement the center of which is corresponding to the axial center of the annular chamber, or the first combustion chamber. For this purpose, any construction can'be employed if it is within the effect of the present invention.

For example, air for combustion can be conducted tangentially into the annular chamber, or the first combustion chamber, by giving it swirling movement through a spiral wing, a tangential groove, or a tangential pipe.

In the first embodiment, the first and the second combustion chambers are disposed mutually in series and in coaxial relation, and in the second embodiment the first combustion chamber is disposed in a vertical or perpendicular plane with respect to the axial direction of the second combustion chamber. But the disposition is not limited to the case mentioned above. Namely, any design variation can be permitted about the disposition and formation of the various components of the vortex combustor of the present invention, according to its objects and its purposes as long as it is within the range of the effect of the present invention.

biles and for aircraft, which are described herein with relation to the first and second embodiments. For example, they can be used as various combustors using heat energy, such a boilers, burners, steam motors, heating apparatus and water boilers. They can also be used as the combustors for heat motors using mechanical energy which is converted from heat energy, such as various steam turbines, gas turbines, jet engines and steam engines, which can be employed in many fields, for example, for aircraft, ships, motor vehicles, electric generation and for industrial motive force in various works.

Obviously, many modifications and variations of the present invention are possible in light of these teachings. It is to be understood therefore, that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.

. Accordingly, what is claimed as new and desired to be secured by Letters Patent of the United States is:

l. A vortex-combustor comprising:

a first combustion unit having a cylindrical wall and an end wall on one end thereof for forming a first combustion chamber;

a second combustion unit having a cylindrical wall and an end wall on one end thereof for forming a second combustion chamber; I

a connecting part having a throttled opening for integrally connecting said two combustion units;

at least one inlet means in said first combustion unit for introducinggas tangentially into said first combustion chamber;'

a fuel supplying device and an igniting device connected to said first combustion unit positioned near the central axis of said first combustion chamber; and

said second combustion chamber having a throttled open part in said second combustion unit opposite said connecting part.

2. A vortex combustor according to claim 1, furthe comprising:

an outer casing having a cylindrical wall and two closed end walls;

means for supporting said first and second combustion units in said outer casing in spaced relation thereto;

at least one inlet passage means provided in said outer casing for introducing gas tangentially within said outer casing; and

at least one outlet passage means provided on said outer casing for discharging combustion gas from said outer casing.

3. A vortex combustor according to claim' 1, wherein said first and second combustion units are disposed coaxially in series.

4. A vortex combustor according to claim 1, further comprising:

a cover plate positioned adjacent said second combustion unit in opposed relation to said throttled open part thereof.

A vortex combustor according to claim 2, further comprising:

a throttle member having at least one opening hole therein disposed between said outer casing and second combustion unit adjacent said throttled open part, being arranged to divide the annular space between said outer casing and said first and second combustion units into an annular chamber connected to said inlet passage means and a mixing chamber connected to said outlet passage means.

6. A vortex combustor according to claim 2, further comprising:

7. A vortex combustor according to claim 6, further comprising: i

a throttle member having atleast one opening hole therein disposed between said outer casing and said cylindrical wall of said second combustion unit Y near said throttled open part thereof, and being arranged to divide the annular space between said outer casing and said first and second combustion units into-an annular chamberconnected to said inlet passage means and a mixing chamber connected to said outlet passage means and an opening between said throttled open part of second combustion unit and said cover plate within said outer casing.

8. A vortex combustor according to claim 3, further comprising: I

an outer casing having a cylindrical wall and two closed end walls being disposed about said first and second combustion units in surrounding relation therewith; at least one inlet passage means provided in said outer casing for introducing gas tangentially within said outer casing; and at least one outlet passage means provided in said outer casing for discharging combustion gas from said outer casing. 9. A vortex combustor according to claim 8, further comprising:

a throttle member having at least one opening hole therein disposed between said outer casing and sec-' ond combustion unit, near said throttled open part thereof, being arranged to divide the annular space between said outer casing and said first and second combustion units into an annular chamber connected to said inlet passage means and a mixing chamber connected to said outlet passage means.

5 10. A vortex combustor according to claim 9, further comprising:

11. A vortex combustor according wherein:

said outer casing is composed of first and second cylinders-each having outward extending flanges on both ends thereof;

one of said end walls of said outer casing being a circular plate fixed on the flange of one end of said first cylinder;

the other end of said first cylinder and one end of said second cylinder being fixed together by their flanges with said throttle member interposed therebetween;

the other of said end walls of said outer casing being said cover plate integrally fixed to the flange of the other end of said second cylinder;

said inlet passage meansis a pipe tangentially arranged into one end of said first cylinder at a position near said circular plate; V

said outlet passage means isa pipe tangentially arranged into one end of said second cylinder at a position near said cover plate; and

said first and second integrally connected combustion units are positioned in the interior of said outer casing, in such a manner that said end wall of said first combustion unit is supported elastically to said circular plate and said throttled open part of said second combustion unit is in opposed relation to said cover plate.

12. A vortex combustor according to claim 10,

wherein:

said outer casing and said first and second combus tion units are annular cylinders.

13. A vortex combustor according to claim 1, where to claim 10,

said first and second combustion units are disposed such that the axes of said two cylindrical walls intersect at a right angle.

14. A vortex combustor according to claim 13, further comprising: i

an outer casing having a cylindrical wall and two closed end walls surrounding said first and second combustion units;

at least one inlet passage meansin said outer casing for introducing gas tangentially into said outer casing; and

at least one outlet passage means in said outer casing for discharging combustion gas from said outer casing.

15. A vortex combustor according to claim l4, further comprising:

a throttle member having at least one opening hole disposed between said outer casing and second combustion unit near said throttled open part of said second combustion unit and being arranged to form an annular chamber connected to said inlet passage means and a mixing chamber connected to said outlet passage means within said outer casing.

16. A vortex combustor according to claim 15, furwherein: ther comprising: the ratio of the diameter of said throttled opening of a co er plate position jace t a d opp t Said said connecting part to the inner diameter of said throttled open part of said second combustion unit. fi combustion i i l s h or equal to Q6; the diameter of said throttled open part in said sec- A 3? combustor according Claim 0nd combustion unit is larger than or equal to the ther compnsmg: v I I diameter of said throttled opening of said connecta wall member extending substantially radially from ing part; and

the cylindrical wall of said second combustion unit and forming a throttled opening surrounded by the 10 inner wall surface thereof for dividing said second combustion chamber into a combustion chamber connected to said first combustion chamber through said throttled opening of said connecting part and a combustion chamber having said throttled open part.

18. A vortex combustor according to claim 17,

the ratio of the cross-sectional area of said at least one inlet means in said first combustion unit to the product of the inner diameter of said first combustion unit and the diameter of said throttled opening of said connecting part is less than 0.1.

20. A vortex combustor according to claim 19,

wherein:

the ratio of the diameter of said throttled open part in said second combustion unit to the inner diamewhcrcin: i

said outer casing and said second combustion unit te 0f Said Second Combustion Unit is less than or are annular cylinders. 7 equal to 0.8.

19. A vortex combustor according to claim 1,

Claims

1. A vortex combustor comprising: a first combustion unit having a cylindrical wall and an end wall on one end thereof for forming a first combustion chamber; a second combustion unit having a cylindrical wall and an end wall on one end thereof for forming a second combustion chamber; a connecting part having a throttled opening for integrally connecting said two combustion units; at least one inlet means in said first combustion unit for introducing gas tangentially into said first combustion chamber; a fuel supplying device and an igniting device connected to said first combustion unit positioned near the central axis of said first combustion chamber; and said second combustion chamber having a throttled open part in said second combustion unit opposite said connecting part.

2. A vortex combustor according to claim 1, further comprising: an outer casing having a cylindrical wall and two closed end walls; means for supporting said first and second combustion units in said outer casing in spaced relation thereto; at least one inlet passage means provided in said outer casing for introducing gas tangentIally within said outer casing; and at least one outlet passage means provided on said outer casing for discharging combustion gas from said outer casing.

3. A vortex combustor according to claim 1, wherein said first and second combustion units are disposed coaxially in series.

4. A vortex combustor according to claim 1, further comprising: a cover plate positioned adjacent said second combustion unit in opposed relation to said throttled open part thereof.

5. A vortex combustor according to claim 2, further comprising: a throttle member having at least one opening hole therein disposed between said outer casing and second combustion unit adjacent said throttled open part, being arranged to divide the annular space between said outer casing and said first and second combustion units into an annular chamber connected to said inlet passage means and a mixing chamber connected to said outlet passage means.

6. A vortex combustor according to claim 2, further comprising: a cover plate positioned adjacent said second combustion unit in opposed relation to said throttled open part thereof.

7. A vortex combustor according to claim 6, further comprising: a throttle member having at least one opening hole therein disposed between said outer casing and said cylindrical wall of said second combustion unit near said throttled open part thereof, and being arranged to divide the annular space between said outer casing and said first and second combustion units into an annular chamber connected to said inlet passage means and a mixing chamber connected to said outlet passage means and an opening between said throttled open part of second combustion unit and said cover plate within said outer casing.

8. A vortex combustor according to claim 3, further comprising: an outer casing having a cylindrical wall and two closed end walls being disposed about said first and second combustion units in surrounding relation therewith; at least one inlet passage means provided in said outer casing for introducing gas tangentially within said outer casing; and at least one outlet passage means provided in said outer casing for discharging combustion gas from said outer casing.

9. A vortex combustor according to claim 8, further comprising: a throttle member having at least one opening hole therein disposed between said outer casing and second combustion unit, near said throttled open part thereof, being arranged to divide the annular space between said outer casing and said first and second combustion units into an annular chamber connected to said inlet passage means and a mixing chamber connected to said outlet passage means.

10. A vortex combustor according to claim 9, further comprising: a cover plate positioned adjacent said second combustion unit in opposed relation to said throttled open part thereof.

11. A vortex combustor according to claim 10, wherein: said outer casing is composed of first and second cylinders each having outward extending flanges on both ends thereof; one of said end walls of said outer casing being a circular plate fixed on the flange of one end of said first cylinder; the other end of said first cylinder and one end of said second cylinder being fixed together by their flanges with said throttle member interposed therebetween; the other of said end walls of said outer casing being said cover plate integrally fixed to the flange of the other end of said second cylinder; said inlet passage means is a pipe tangentially arranged into one end of said first cylinder at a position near said circular plate; said outlet passage means is a pipe tangentially arranged into one end of said second cylinder at a position near said cover plate; and said first and second integrally connected combustion units are positioned in the interior of said outer casing, in such a manner that said end wall of said first combustion unit is supported elastically to said circular plate and said thRottled open part of said second combustion unit is in opposed relation to said cover plate.

12. A vortex combustor according to claim 10, wherein: said outer casing and said first and second combustion units are annular cylinders.

13. A vortex combustor according to claim 1, where said first and second combustion units are disposed such that the axes of said two cylindrical walls intersect at a right angle.

14. A vortex combustor according to claim 13, further comprising: an outer casing having a cylindrical wall and two closed end walls surrounding said first and second combustion units; at least one inlet passage means in said outer casing for introducing gas tangentially into said outer casing; and at least one outlet passage means in said outer casing for discharging combustion gas from said outer casing.

15. A vortex combustor according to claim 14, further comprising: a throttle member having at least one opening hole disposed between said outer casing and second combustion unit near said throttled open part of said second combustion unit and being arranged to form an annular chamber connected to said inlet passage means and a mixing chamber connected to said outlet passage means within said outer casing.

16. A vortex combustor according to claim 15, further comprising: a cover plate positioned adjacent and opposed to said throttled open part of said second combustion unit.

17. A vortex combustor according to claim 15, further comprising: a wall member extending substantially radially from the cylindrical wall of said second combustion unit and forming a throttled opening surrounded by the inner wall surface thereof for dividing said second combustion chamber into a combustion chamber connected to said first combustion chamber through said throttled opening of said connecting part and a combustion chamber having said throttled open part.

18. A vortex combustor according to claim 17, wherein: said outer casing and said second combustion unit are annular cylinders.

19. A vortex combustor according to claim 1, wherein: the ratio of the diameter of said throttled opening of said connecting part to the inner diameter of said first combustion unit is less than or equal to 0.6; the diameter of said throttled open part in said second combustion unit is larger than or equal to the diameter of said throttled opening of said connecting part; and the ratio of the cross-sectional area of said at least one inlet means in said first combustion unit to the product of the inner diameter of said first combustion unit and the diameter of said throttled opening of said connecting part is less than 0.1.

20. A vortex combustor according to claim 19, wherein: the ratio of the diameter of said throttled open part in said second combustion unit to the inner diameter of said second combustion unit is less than or equal to 0.8.