US3866585A

US3866585A - High energy fuel atomization and a dual carburetion embodying same

Info

Publication number: US3866585A
Application number: US081706A
Authority: US
Inventors: Richard D Kopa
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-10-19
Filing date: 1970-10-19
Publication date: 1975-02-18
Anticipated expiration: 1992-02-18
Also published as: CA950777A

Abstract

A fuel atomizing carburetion system incorporating means for fuel atomization and flash vaporization in a heated evaporation chamber, separated from the main air induction system, and means for transferring the fuel vapor into a cyclonic flow inductor in which a mixing process with the cold inlet air occurs, for the purpose of generating a well-homogenized combustible mixture of completely vaporized fuel, inlet air, and recycled exhaust gas, with a minimal temperature rise of the mixture, in order to avoid the consequent increase of nitric oxide formation during the engine combustion process. A fuel atomizing carburetion system incorporating a pneumatic control system for the continuous control of the air-fuel ratio, exhaust gas recycling rate, and of the heat transfer rate to the atomized vaporizing fuel, in order to obtain an optimal reduction of engine exhaust emission and optimal engine performance.

Description

finite States atent n91 Kopa 1 1 Feb. 18, 1975 HIGH ENERGY FUEL ATOMIZATION AND A DUAL CARBURETION EMBODYING SAME [76] Inventor: Richard D. Kopa, 6014 Wish Ave.,

Encino, Calif. 91316 [22] Filed: Oct. 19, 1970 [21] Appl. No: 81,706

[52] U.S. CL. 123/119 A, 123/127 [51] Int. Cl. F02m 25/06 158] Field of Search 123/119 A, 127

[56] References Cited UNITED STATES PATENTS 3,273,161 9/1966 Di Giorgio 123/119 A 3,384,059 5/1968 Kopa 123/119 R 3,397,682 8/1968 Riggan 123/119 A 3,498,274 3/1970 Chapman... 123/119 A 3,580,233 5/1971 Busse 123/119 A Primary Examiner-Wendell E. Burns [57] ABSTRACT A fuel atomizing carburetion system incorporating means for fuel atomization and flash vaporization in a heated evaporation chamber, separated from the main air induction system, and means for transferring the fuel vapor into a cyclonic flow inductor in which a mixing process with the cold inlet air occurs. for the purpose of generating a well-homogenized combustible mixture of completely vaporized fuel, inlet air, and recycled exhaust gas, with a minimal temperature rise of the mixture, in order to avoid the consequent increase of nitric oxide formation during the engine combustion process. A fuel atomtizing carburetion system incorporating a pneumatic control system for the continuous control of the air-fuel ratio, exhaust gas recycling rate, and of the heat transfer rate to the atomized vaporizing fuel, in order to obtain an optimal reduction of engine exhaust emission and optimal engine performance.

7 Claims, 7 Drawing Figures HIGH ENERGY FUEL ATOMIZA'IION AND A DUAL CARBURETION EMBODYING SAME This invention relates generally to carburetors for internal combustion engines and has more particular reference to improvements in fuel'atomizing carburetors. It has become apparent from research in automotive air pollution that the three major contaminants present in the exhaust gas emissions from gasoline powered motor vehicle engines are carbon monoxide, hydrocarbons, and nitrogen oxides. The inventions disclosed in my previous U.S. Pat. Nos-3,376,027 entitled Fuel Atomizing Carburetors, 3,336,0l7 entitled Compound Cyclonic Flow Inductor and Improved Carburetor Embodying Same, 3,395,899 entitled Carburetor, and 3,384,059 entitled Carburetion System with Improved Fuel-Air Ratio Control System-propose certain new and unique carburetion techniques which are effective to reduce substantially the air contaminants, particularly the three major contaminants just listed, which are present in automotive gas emissions. More specifically, my prior inventions, just referred to, relate to improved fuel atomizing carburetors which utilize, among others, two effective techniques for reducing exhaust gas contaminants. One of these techniques is that of introducing exhaust gas, or other inert fluid, either liquid or gaseous, into the airfuel mixture entering the engine to reduce the peak combustion temperature of the mixture, and thereby, the formation of nitrogen oxides. It should be noted that when emitted into the atmosphere, the nitric oxide converts to nitrogen dioxidea toxic gaswhich upon exposure to sunlight acts as a photoreceptor and, in the presence of unburned hydrocarbons, triggers the photochemical reactions in contaminated atmosphere leading to the manifestations commonly called smog. The second technique is that of effecting substantially total vaporization of the fuel and substantially complete homogeneous intermixing of the fuel vapor, induction air, and recycled exhaust gas in such manner as to permit engine operation at an air-fuel ratio with a substantial excess of air and thereby achieve more complete combustion of the hydrocarbons in the fuel and reduce the formation of carbon monoxide. To preserve at the same time a good engine operating characteristic, it is necessary to ensure that every cylinder of a multicylinder engine is supplied with a wellhomogenized combustible mixture of the same air-fuel ratio from cylinder to cylinder and from cycle to cycle. The inventions disclosed in my previous patents accomplish this task by the following means: (1) fuel atomization, (2) instant vaporization of fuel droplets, (3) recycling of exhaust gas for the control of nitric oxide, and (4) homogcnation of the combustible mixture by cyclonic mixing of the vaporized fuel, inlet air, and the recycled exhaust gas. In particular, my U.S. Pat. No. 3,336,017, Compound Cyclonic Flow Inductor and Improved Carburetor Embodying Same, describes a carburetion process for complete vaporization of atomized fuel in air which is subjected to compound cyclonic motion in a specially designed flow inductor-mixing chamber. The heat necessary for the vaporization of fuel is supplied by means of a heated fluid jacket enveloping the outer periphery of the mixing chamber.

Evidently, the heating of the inlet air as required for complete vaporization of the supplied fuel will result in a rise in the temperature of the combustible mixture. It is well known, however, that an increase in air-fuel mixture temperature will result in higher combustion temperature and, consequently, in higher emission of nitric oxide. The general objective of the present invention is to eliminate this particular deficiency and further to improve several other aspects of the inventions disclosed in my previous patents.

Briefly, the objects of the invention are attained by providing a means for separating the flow of inlet air into a minor portion passing through an evaporation chamber and the major portion of air passing through the cyclonic flow inductor. In this manner, only that amount of the total air flow is h.eated-about 10%-- which is necessary for the vaporization of fuel in the evaporation chamber, and remains cold, to be later homogenized in the cyclonic flow inductor, along with the recycled exhaust gas, fuel vapor, and the aforementioned small amount of warm air. Thus a reduction in the temperature of the combustible mixture and a concomitant reduction in the formation of nitric oxides is effected. It should be noted that the relationship between the formation ot the nitrogen oxides and the combustion temperature is an exponential one. Accordingly, even a small decrease in the peak combustion temperature results in a substantial reduction in the formation of nitrogen oxides.

Of course, the system must be: effective under twofold conditions, to wit, during steady state engine oper' ation, e.g., cruising and idling, and during transient engine operation, e.g., acceleration and deceleration. To this end, the present carburetor has been provided with a control system which maintains the correct air-fuel ratio for optimum engine performance and optimum emission control throughout the entire operating range of the engine.

With these and other objects in view, the invention consists in the construction, arrangement, and combination of the various parts of the invention, whereby the objects contemplated are attained, as hereinafter set forth, pointed out in the appended claims, and illustrated in the accompanying drawings.

The invention will be now described in greater detail by reference to the attached drawings, wherein:

FIG. 1 illustrates the principle of High Energy Fuel Atomization according to this invention;

FIG. 2 is a vertical section through the carburetor, the cyclonic mixing chamber, and the engine inlet manifold; taken on 2-2 FIG. 3 is a horizontal section through the carburetor and the mixing chamber;

FIG. 4 is a horizontal section through the carburetor main body;

FIG. 5 is a vertical section through the carburetor primary barrel;

FIG. 6 is a vertical section through the carburetor secondary barrel; and

FIG. 7 is a section taken on line 7-7 in FIG. 4.

The principle of high energy fuel atomization and flash vaporization is schematically presented in FIG. 1. Air enters the inlet 1 of a compound cyclonic flow inductor 2, passes through the main throttle valve 3 and helical veins 4 located circumferentially around the venturi 5. Fuel enters through a duct 6 the pneumatic atomizing nozzle 7 and is atomized by means of preheated atomizing air supplied through a duct 8 and injected into evaporation chamber 9, which is enveloped by a fluid heating jacket I0. A small amount of secondary air, less the 10% of the total air-inlet quantity, passes through the evaporation chamber 9 in order to increase the rate of flow-through and promote the turbulence and fuel evaporation process in the evaporation chamber 9. The rate of flow of the secondary air is controlled by a throttle valve 11 which is synchronized with the main throttle valve 3 by means of linkage 12. Hot recycled exhaust gas, primarily for the control of nitric oxide, is injected in close vicinity to the atomizing nozzle 7 through a duct 13. The heat of the recycled exhaust gas contributes to instant vaporization of the atomized fuel droplets. The mixture of vaporized fuel, secondary air, and recycled exhaust gas is aspirated through the venturi and is discharged into the primary air stream which is spinning cyclonically about a longitudinal axis of the inlet section 14 of the compound cyclonic flow inductor l. The resulting confined cyclonically spinning mixture stream is guided to turn to 'one side and into a circular flow path closing on itself, such that the mixture stream continues its cyclonic spin, and spins additionally around the circular flow path, effecting an intensive turbulent intermixing of all components. The homogenized combustible mixture is drawn off through a large number of holes in a perforated baffle 15 into the inlet barrels 16 of the engine inlet manifold. The cyclonic flow inductor 2 has no heating jacket, and consequently no heat from the heating fluid is transferred, to the primary inlet air entering through the main throttle valve 3. As compared to the carburetion process described in my previous U.S. Pat No. 3,336,0l7, where the entire combustible mixture is heated to the fuel vaporization temperature, the process of this invention represents a substantial reduction of necessary heat input for the total vaporization of atomized fuel and also a substantial reduction in the resulting temperature of the combustible mixture. The magnitude of this reduction becomes evident when one considers that a mass of fifteen, or more,

pounds of air is carbureted with the mass of every one pound of fuel. Since in this process the resulting temperature of the combustible mixture is below the equilibrium temperature of the fuel vapor, the fuel vapor after mixing with the primary cool air becomes super coiled. However, because of the high flow velocity of the combustible mixture in the entire carburetion and engine inlet system, there is not sufficient time for conden sation of the fuel vapor back to liquid state. Therefore, the fuel persists in a gaseous state until it arrives to the individual cylinders of the engine.

A physical embodiment of the above principle is presented in FIG. 2 and FIG. 3. For the reason of compactness, the evaporation chamber 9 is wrapped around the cyclonic flow inductor 2. In this way, the primary air throttle valve 3 and the secondary air throttle valve 11 can be mounted on a common shaft 17 in a single carburetor body 18 containing side by side a primary air inlet barrel 19 and secondary barrel 20. The mixing venturi 5 is replaced by a series of blades 21 located circumferentially around the cyclonic flow inductor 2 in such a fashion that they replace a major part of the outer wall of the flow inductor 2 and permit the flow of the fuel vapor, secondary air, and recycled exhaust gas mixture from the evaporation chamber 9 into the cyclonic flow inductor 2 but prevent, because of aerodynamic forces, the flow in the reverse direction, namely, from the cyclonic flow inductor 2 into the evaporation chamber 9. The evaporation chamber 9 is on its outer circumference and bottom part enveloped by a heating jacket 10, which extends also over the bottom part of the cyclonic flow inductor 2. The heat transfer from the jacket 10 to the combustible mixture in the cyclonic flow inductor 2 is barred by means of a set of circular concentric step-baffles 22 arranged in the vicinity above the sloping bottom wall 23 of the flow inductor 2. The step-baffles 22 permit, however, any liquid fuel which was injected directly into the cyclonic flow inductor 2 and remained unvaporized to flow through the circular clearances 24 between the step-baffles 22 onto the heated sloping wall 23 and have another chance to be vaporized.

At light and medium loads of engine operation,,the major portion of the supplied fuel (about 90percent) is atomized by means of the pneumatic atomizing nozzle 7 located in the secondary barrel 20 and injected into the evaporation chamber 9. The minor portion of the supplied fuel, about l0%, is atomized by means of the pneumatic atomizing nozzle 25 located in the primary barrel l9 and injected directly into the cyclonic flow inductor 2. At the same time, the inlet air flow distribution ratio is the reverse. That is, in the same way as indicated in FIG. 1, a major portion of inlet air (about 90%) flows through the primary barrel 19, and the minor portion of inlet air flows through the secondary barrel 20. The minor portion of fuel atomized directly into the cyclonic flow inductor 2 vaporized partially or completely by means of heat which it extracts from the surrounding (major) inlet air, which in turn is efficiently cooled below its original ambient temperature. On the other hand, the major portion of fuel atomized into the evaporation chamber 9 is instantly vaporized by the efficient heat transfer from the recycled hot exhaust gas, injected through openings 26 circumferentially distributed at the entrance of the evaporation chamber 9, and from the super-heated minor portion-or secondaryinlet air and the fuel vapor. The optimal super-heating of the combustible mixture inside the evaporation chamber can be attained by the design for optimal ratio of the mixture mass flow rate through the jacket-heated evaporation chamber 9 to the flow rate of the heating fluid through the heating jacket 10. The heating jacket 10 has inlet and exhaust flanges 27, which are connected to short bypass ducts 28. The bypass ducts 28 are fitted into the openings drilled in the cross-over heating passage 29 of the engine inlet manifold 30. The ducts 28 are sealed against a leakage by means of copper sleeves 31 clamped to the inlet manifold 30. The inserted portions of the ducts 28 are shaped in such a way as to block off the flow of exhaust gases through the crossover heating passage 29 and divert the flow through the heating jacket 10. By these means, first, an undue heating of the already homogenized combustble mixture in the engine inlet manifold 30 is prevented, and, secondly, because of the short length of the bypass ducts 28, the radiation heat losses of the heating fluid are minimized. Between one flange 27 and duct 28 is mounted a throttle valve 32. The opening position of valve 32 is set by a pneumatic actuator 33 which responds to the controlled vacuum from controller 34. The controller 34 responds to several pertinent input signals, such as the engine manifold vacuum 35, engine temperature 36, exhaust gas emis- During engine acceleration and or high engine load operation, the ratio of air flow through secondary barrel 26 to air flow through primary barrel 19 is increased in order to intensify the mixing process in chamber 9 as well as in the cyclonic flow inductor 2. This is accomplished by a special shape of the throttle valve 11 as shown in FIG. 6. At the same time, the ratio of fuel injection rate from the atomizing nozzle 25 to the fuel :njection rate from the atomizing nozzle 7 is increased inorder to obtain good acceleration response and maximum power at full load operation. This is accomplished by the mechanism described in FIG. 4 through FIG. 7. The rate of exhaust gas recycling is adjusted by n throttle valve 38, which is positioned by a pneumatic actuator 39 responsive to the regulated vacuum from the controller 34. The controller 34 optimizes the exhaust recycling rate to achieve the lowest nitric oxide emission and the best engine performance trade-off. During engine deceleration, the over-all air-fuel ratio is adjusted to obtain the lowest emission of unburned hy drocarbons by means of the controller 34 and the

regulators

40 and 41, as described in detail in FIG. 6 and FIG. 7.

The engine cylinder inlet and exhaust valve timing, the inlet manifold configuration and volume, and the conventional carburetor have to be tuned together in order to obtain a reliable idling of the engine at low RPM. If the conventional carburetor is replaced by a fuel atomizing carburetor with a cyclonic mixing chamber of considerable volume, the original gasdynamical tune-up of the induction system is likely to be upset, and the engine will not satisfactorily idle at factory specified RPM. To eliminate this problem, the fuel atomizing carburetor described herein is provided with auxiliary throttle valves 42 attached to the shaft 43 in exactly the same location in respect to the inlet manifold 30 as were the throttle valves of the original conventional carburetor. The motion of shaft 43 of the auxiliary valves 42 is synchronized by means of linkage with the motion of the shaft 17 of the primary throttle valve 3 and the secondary throttle valve 11. The link age is designed so as to allow a small advance in the opening motion to the auxiliary valves 42 in order to transmit a full manifold vacuum to the space inside the flow inductor and evaporation chamber assembly. To prevent eventual damage of the carburetor from accidental backfire in the induction system, the cyclonic mixing chamber is provided with a spring-loaded lid 43 for instantaneous release of the explosion pressure.

The

fuel atomizing nozzles

7 and 25 are described in FIG. 4 through FIG. 7. Both nozzles are of the external mixing type; this means that the atomizing air which enters the carburetor body 18 through a channel 44, and isdistributed by means of the branch 45 to nozzle 7 and branch 46 to nozzle 25, expands at high velocity through

clearances

47 and 48, respectively, and atomizes by a mechanism of molecular collision the fuel emerging from

nozzle mouths

49 and 50, respectively. The rate of fuel flow is controlled by means of the needle 51 positioned in the metering orifice 52 of the atomizing nozzle assembly 7 and by the needle 53 and orifice 54 for the nozzle 25, FIG. 7, as well as by the suction pressure maintained in the space 55 on the discharge side of the orifice 52 and in the space 56 on the discharge side of the orifice 54. The suction pressure is regulated by means of the pressure regulator 40 or the regulator 41, selectively, in the following way: If the teflon sliding valve 57 is in closed position in respect to channel 58, then the atmospheric air can enter only the bottom side of the regulating diaphragm 59 of the regulator 40 by means of the channel 60. The suction pressure existing in the space 61 is communicated to the upper side of the diaphragm 62 by means of the feedback channel 63. The pressure difference between the atmospheric pressure on the bottom side of 59 and the suction pressure at the upper side of 62 exerted over the area of the

diaphragms

59 and 62 balances the spring 64, which forces the diaphragm 59 against the seat 65, in such a way that a nearly constant suction pressure in the space 52 and the space 56 is maintained independently of the manifold vacuum fluctuation in the evaporation chamber 9 and the cyclonic flow inductor 2. The tension of the spring 64 in the regulator 40 is adjusted by means of screw 66, so as to maintain a certain suction pressure level corresponding to a desired air-fuel ratio setting of the carburetor at cold start and cold engine operation. As the engine warms up, a conventional thermostat rotates the shaft 67 to pull the teflon valve in the open position so that the atmospheric air is transferred by means of channel 58 to the regulator 41. The tension of the spring 68 is adjusted by means of screw 69 to a substantially lesser value, and consequently the suction pressure in the spaces 52 g and 56 will be maintained at a level corresponding to a leaner air-fuel ratio setting as required during hot engine operation. The system described above maintains a constant air-fuel ratio over a wide range of the manifold vacuum, with a progressive enrichment of the airfuel ratio as the manifold vacuum approaches lowest values at high load engine operation. It is essential, however, that the air-flow as regulated by the

pressure regulator

40 or 41 is directed against the discharge side of the metering orifices 52 and 54 in such a way that a stagnation pressure corresponding to the regulated pressure level exists at the metering orifices. The geometry of the

spaces

56 and 52 is apparent in FIG. 6 and FIG. 7.

Since the atomizing nozzle 25 is remote from the metering orifice 54, the mixture of fuel and air emerging from the apace 56 is transferred by means of channel 70, which merges tangentially into the swirl cavity 71 located in the proximity of the atomizing nozzle discharge mouth 50. By the resulting swirling motion in cavity 71, the air bubbles are separated from the aspirated fuel, as is essential for even discharge and smooth atomization of fuel by the atomizing nozzle 25. At full throttle operation, the manifold. vacuum reduces to nearly atmospheric pressure, and consequently both

regulators

40 and 41 will maintain the same suction pressure in

spaces

56 and 52, resulting in the same airfuel ratio. To compensate for this deficiency, an air valve 72 is provided in the primary barrel 19. The air valve 72 is mounted on shaft 73 with attached torsional spring 74. The end of the spring 74 engages with a pin 75 located on a slide 76, which is positioned by arm 77 attached to the thermostat shaft 67. At cold engine operation, the thermostat shaft 67 is rotated clockwise, closing the teflon valve 57 and moving the slide 76 to a position in which the pin 75 engages with the spring 74. The air valve 72 which is opened in proportion to air flow through the primary barrel 19 must rotate against the tension of spring 74, and therefore exerts a choking effect on the air flow through the barrel 19. At hot engine operation, the thermostat shaft 67 is rotated counterclockwise, and the pin 75 is disengaged from the spring 74 so that the air valve 72 can rotate freely. A hydraulic dashpot can be attached to the shaft 73 so that at a sudden opening of the throttle valve 3 the air valve 72 opens progressively, thus effecting a temporary enrichment of the air-fuel mixture during acceleration. An additional enrichment of the air-fuel mixture during acceleration and high load operation is provided by means of an auxiliary power nozzle 78, which is supplied with fuel from a conventional diaphragm fuel chamber 79. The diaphragm 80 becomes inoperative, however, at high inlet manifold vacuum, corresponding to lighter engine load. This is accomplished by immobilizing the diaphragm 80 on the seat 81 by means of suction in the conduit 82. The suction in the conduit 82 results when the air bleeder flow through the orifice 83 is unbalanced by the suction flow through the orifice 84 at elevated manifold vacuum.

As mentioned above, the emission of unburned hydrocarbons during deceleration can be substantially reduced if the air-fuel ratio of the combustible mixture is temporarily increased. Such transient increase of airfuel ratio can be conveniently accomplished by means of a controller with a built-in variable-lead function, as shown in FIG. 7. A controller 85, which represents a simplified version of a more complex controller system 34 as indicated in FIG. 2, is connected to the inlet manifold by means of a threaded port 86. The sudden rise in, manifold vacuum during engine deceleration is transmitted to the cavity 87 below the diaphragm 88, and through a restricting orifice 89 to the cavity 90 above the diaphragm 88. Because the cavity 90 is larger than cavity 87 and communicates with the manifold vacuum through the restriction 89, any change in pressure signal at 86 will manifest itself more slowly in cavity 90 than in cavity 87. Consequently, a sudden increase of manifold vacuum will cause the diaphragm to move downward and to open the valve 91. Therefore, the manifold vacuum will be transmitted to the channel 91, and by means of conduit 93 to the space between the

diaphragms

59 and 62 of the

pressure regulators

41 and 40. The diameter and corresponding surface of the diaphragm 59 is larger than that of diaphragm 62. Therefore, the supplied vacuum will result in a differential pressure upward against the tension of the

springs

64 and 68, with the effect of a leaner adjustment of the air-fuel ratio. As soon as the pressure in caivity 90 equalizes with the pressure in cavity 87, the

spring 94 closes the valve 91, and the vacuum in the conduit 93 dissipates through the bleeder orifice 95 so that the steady state condition is reestablished. The duration and timing function of this transient leaning can be modified by the choice of the volume ratio of

cavities

87 and 90, and by the choice of the proper size of .

orifices

89 and 95. Superimposed on this method can be a steady state modification of the air-fuel ratio as a function of the manifold vacuum by means of a bleeder orifice 96 continuously communicating the manifold vacuumsignal to the channel 92.

It is evident that similar controller-regulator systems can be employed to control the exhaust recycling valve 38 or the heat input control valve 32 of the jacket 10. All such components can be combined in one integral controller unit 34, as suggested in FIG. 2 and FIG. 3, and developed to the desired degree of sophistication in order to satisfy best the trade-off of requirements for 8 low emmission, engine performance, and simplicity of the whole system.

The positioning motion of the needle valves 51 and 53 is synchronized with the opening motion of the

throttle valves

3 and 11, so as to maintain a nearly constant opening ratio of the total air flow area to the total fuel flow area throughout the entire operating range. The motion from the shaft 17, FIG. 4 through FIG. 7, is transmitted by means of the attached arm 97 and a roller 98 to a pivoted actuating arm 99. The arm 99 rests against an actuating pin 100, which is supported by a compression spring 101. At the lower extension of the pin 100 is attached needlle valve 53, and by means of brace 102 is attached needle valve 51. Needle valve 53 penetrates through the fuel metering orifice 54 into a fuel collector 103, and needle valve 51 penetrates through fuel metering orifice 52 into fuel collector 104.

For a reliable start of the cold engine, a large amount of fuel has to be supplied during the cranking operation. This is accomplished in the present invention in the following way: During cold start, the teflon slide valve 57, FIG. 6, closes off the channel 58. A similar valve actuated from the thermostat shaft 67 located beside the valve 57 closes off channel 105, FIG. 7. Channel 105 communicates with the well 106 and the discharge channel 107, FIG. 4. The well 106 is vented by a bleeder vent 1076. During cranking of the engine, the spring 108 holds the diaphragm 109 away from the seat 110, and fuel is aspirated from the fuel float chamber 111 into the discharge channel 107, and through the discharge port 112 into the conduit 113. Conduit 113, FIG. 4, delivers the fuel directly to inlet barrels 16, FIG. 3, above the engine inlet manifold 30. Once the engine starts, the manifold vacuum is transmitted through the conduit 113 into the cavity 114 above the diaphragm 109, which is pulled against the seat and shuts off further delivery of the startingfuel. As soon as the engine warms up, the thermostat shaft 67 rotates counterclockwise and a teflon slide valve opens the channel 105. If the engine is being restarted, no starting fuel is aspirated, since the suction in the discharge channel 107 is abosrbed by the air flow through the open channel 105.

While the invention has herein been shown and described in what is conceived to be its most practical and preferred embodiments, it is recognized that departures may be made therefrom within the scope of the invention, which is not to be limited to the details disclosed herein, but is to be accorded the full scope of the.

claims so as to embrace any and all equivalent devices.

I claim: 1. A liquid fuel and air carburetion process for an internal combustion engine, that comprises:

providing one confined minor and one confined major stream of intake air spinning cyclonically about a longitudinal spin axis; jetting into the minor air stream, in the downstream direction thereof, an expanding major spray of liquid fuel that is atomized by impingement by a stream of pressurized gas directed downstream along said axis so as to mix the atomized and vaporizing liquid fuel with said minor air stream, and the recycled hot exhaust gas, injected in close proximity of said expanding major spray of liquid fuel; guiding the resulting confined turbulent mixture stream through a heated space where a complete vaporization of liquid fuel takes place and transferring said mixture stream into another unheated space where a mixing with a confined cyclonically spinning major stream of unheated intake air takes place;

guiding the final confined cyclonically spinning mixture stream to turn to one side and into a circular flow path closing on itself, such that the mixture stream continues its cyclonic spin, and spins additionally around said circular flow path;

drawing off vaporized and homogenized mixture from the mixture stream travelling around said circular flow path.

2. The subject matter of claim 1, including jetting, into the spinning major stream of inlet air, in the downstream direction thereof, an expanding minor spray of liquid fuel that is atomized by impingement of pressurized gas.

3. A carburetor for supplying a combustible, wellhomogenized air-fuel mixture to the intake manifold of an internal combustion engine, comprising:

a housing having a dual induction air passage and a dual fuel discharge means, a means for introducing recycled exhaust gas, a means for evaporation of the atomized fuel and a means for cyclonic homogeneous mixing of all gaseous components,

said dual induction air passage separating the flow of inlet air into avminor portion of air entering into a fuel evaporation chamber, and into a major portion of air entering directly into a cyclonic flow inductor, said dual fuel discharge means delivering the major portion of atomized fuel into said fuel evaporation chamber and the said minor portion of atomized fuel into the inelt of said cyclonic flow inductor, in order to further reduce the temperature of said major portion of inlet air, said means for introducing recycled exhaust gas into the said fuel evaporation chamber, in order to increase the rate of vaporization of the atomized fuel due to heat transfer from the hot recycled exhaust gas to the atomized fuel droplets,

and means for transferring of the mixture of vaporized fuel, recycled exhaust gas and of the minor portion of inlet air into the said cyclonic flow inductor where the homogeneous intermixing of all said gaseous components with said major portion of unheated inlet air takes place, in order to produce well-homogenized combustible mixture, substantially below the equilibrium temperature of said vaporized fuel, persisting in super cooled" state of the fuel vapor.

4. The subject matter of claim v3, including auxiliary throttle valves mounted in the outlet of said cyclonic flow inductor in exactly the same location in respect to the engine inlet manifold as the throttle valves of a con ventional carburetor,

said auxiliary throttle valves synchronized by means of a lost motion linkage with the primary and secondary throttle valves, located in said dual induction air passage of the carburetor, in such a way as to allow a small advance in the opening as well as in the closing motion of the auxiliary throttle valves, in order to obtain smooth idling of the engine and to decrease the emission of unburned hydrocarbons during the deceleration mode of'operation.

5. The subject matter of claim 3, including step baffles arranged in the vicinity above the heated sloping of said cyclonic flow inductor in such a way as to prevent the heat transfer from said heated wall tothe combustible mixture, however, to permit any liquid fuel which remained unvaporized to flow between the step-baffles onto a heated wall and have another chance to be vaporized.

6. The subject matter of claim 3, including means for aerodynamical draw-off of the gaseous mixture from said evaporation chamber into said cyclonic flow inductor.

7. The subject matter of claim 3, including means for additional control of air flow through said dual induction air passage at cold as well as hot engine operation during sudden opening and the wide open position of said primary throttle valve.

Claims

1. A liquid fuel and air carburetion process for an internal combustion engine, that comprises: providing one confined minor and one confined major stream of intake air spinning cyclonically about a longitudinal spin axis; jetting into the minor air stream, in the downstream direction thereof, an expanding major spray of liquid fuel that is atomized by impingement by a stream of pressurized gas directed downstream along said axis so as to mix the atomized and vaporizing liquid fuel with said minor air stream, and the recycled hot exhaust gas, injected in close proximity of said expanding major spray of liquid fuel; guiding the resulting confined turbulent mixture stream through a heated space where a complete vaporization of liquid fuel takes place and transferring said mixture stream into another unheated space where a mixing with a confined cyclonically spinning major stream of unheated intake air takes place; guiding the final confined cyclonically spinning mixture stream to turn to one side and into a circular flow path closing on itself, such that the mixture stream continues its cyclonic spin, and spins additionally around said circular flow path; drawing off vaporized and homogenized mixture from the mixture stream travelling around said circular flow path.

3. A carburetor for supplying a combustible, well-homogenized air-fuel mixture to the intake manifold of an internal combustion engine, comprising: a housing having a dual induction air passage and a dual fuel discharge means, a means for introducing recycled exhaust gas, a means for evaporation of the atomized fuel and a means for cyclonic homogeneous mixing of all gaseous components, said dual induction air passage separating the flow of inlet air into a minor portion of air entering into a fuel evaporation chamber, and into a major portion of air entering directly into a cyclonic flow inductor, said dual fuel discharge means delivering the major portion of atomized fuel into said fuel evaporation chamber and the said minor portion of atomized fuel into the inelt of said cyclonic flow inductor, in order to further reduce the temperature of said major portion of inlet air, said means for introducing recycled exhaust gas into the said fuel evaporation chamber, in order to increase the rate of vaporization of the atomized fuel due to heat transfer from the hot recycled exhaust gas to the atomized fuel droplets, and means for transferring of the mixture of vaporized fuel, recycled exhaust gas and of the minor portion of inlet air into the said cyclonic flow inductor where the homogeneous intermixing of all said gaseous components with said major portion of unheated inlet air takes place, in order to produce well-Homogenized combustible mixture, substantially below the equilibrium temperature of said vaporized fuel, persisting in ''''super cooled'''' state of the fuel vapor.

4. The subject matter of claim 3, including auxiliary throttle valves mounted in the outlet of said cyclonic flow inductor in exactly the same location in respect to the engine inlet manifold as the throttle valves of a conventional carburetor, said auxiliary throttle valves synchronized by means of a ''''lost motion linkage'''' with the primary and secondary throttle valves, located in said dual induction air passage of the carburetor, in such a way as to allow a small advance in the opening as well as in the closing motion of the auxiliary throttle valves, in order to obtain smooth idling of the engine and to decrease the emission of unburned hydrocarbons during the deceleration mode of operation.

5. The subject matter of claim 3, including step-baffles arranged in the vicinity above the heated sloping of said cyclonic flow inductor in such a way as to prevent the heat transfer from said heated wall to the combustible mixture, however, to permit any liquid fuel which remained unvaporized to flow between the step-baffles onto a heated wall and have another chance to be vaporized.