EP0211097A1

EP0211097A1 - Method and carburetor for producing a fuel mixture

Info

Publication number: EP0211097A1
Application number: EP85109784A
Authority: EP
Inventors: Alexander T. Pol
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-08-03
Filing date: 1985-08-03
Publication date: 1987-02-25

Abstract

A method and device for producing a fuel mixture for an internal combustion engine or burner, comprising generators (G1, G2) of microaerosol particles of carrier and fuel substances. The resultant homogeneous fuel mixture and the substantially increased total surface area of the fuel particles enhance considerably the efficiency of combustion of the fuel mixture.

Description

BACKGROUND OF THE INVENTION

Field of the Invention:

This invention relates to methods and devices for producing fuel mixtures, and more particularly, to the production of microaerosol particles of water, fuel and/or oxidizer in an optimum fuel mixture for internal combustion engines or burners.
The process of combustion of liquid fuel in an internal combustion engine or burner is determined by composition and degree of atomization of the fuel mixture. Even when the proportions of fuel and air are optimally chosen, there is still the problem of incomplete combustion and consequent diminished performance of the engine as well as pollution of the environment.
In addition to certain optimal conditions pertaining to the fuel/air mixture, there are also desired optimum conditions relating to the water content in the fuel mixture. The water content in the fuel mixture modifies the process of combustion, and there is ample reason to obtain an optimum water content in a fuel mixture to maximize burning of the fuel and to minimize pollution of the environment.

Prior Art:

Various attempts have been made in the prior art to achieve optimum air/fuel mixtures, including introduction of water into the mixture, and to thoroughly atomize or vaporize the mixture before introducing it into the cylinders of the engine.
For instance, U.S. Patent 3,911,871 describes a system for adding water to the intake system of an engine, and uses a vacuum controlled injector which passes water over an ultrasonic atomizer 52 to atomize the water. U.S. Patent 4,183,338 uses exhaust gas and vacuum conditions at the PCV inlet to achieve a control of the flow of fuel into the engine. Vortex chambers are used as the controlling devices in conjunction with exhaust gas pressure and PCV vacuum. U.S. Patent 4,324, 209 describes an apparatus for obtaining an homogenized fuel/water mixture and then vaporizing it before admixing the mixture into the engine.
Other attempts of supplying water to internal combustion engines are described in U.S. Patents 2,218,522; 2,352,267; 3,325,976; 3,608,529; 3,980,055; 4,005,683; 4,018,192, 4,030,457 4,442,802; 4,448,153; 4,448,170; and 4,463,708. The simple addition of water, however, does not result in significantly higher efficiency of the engine. Thus, although the introduction of water as steam or liquid does reduce atmospheric contamination caused by unburned products of combustion, and results in lowering of temperature of the combustion process, the problem of preparation of the optimal fuel mixture still remains.
An arrangement described in U.S. Patent 4,048,963, does not give completely satisfactory results. The ultrasonic vibration produces an emulsion, but the emulsion burns slowly and does not significantly increase the efficiency of the engine. The inhomogeneity of the emulsion particles of the mixture of fuel and water implies the shortcomings of its application.
The prior art thus describes several methods and devices for the injection of water and/or the control of injection with regard to the cycle of the engine. However, in all cases the fuel and water are separate particles, and the resultant fuel mixture is inhomogeneous.

SUMMARY OF THE INVENTION

The primary object of the invention is to provide a fuel mixture having an extremely high degree of dispersion of fuel particles with a high total surface area of the fuel particles.
Another object of the invention is to provide a fuel mixture in which a uniform and homogeneous mixture of particles of fuel and carrier is obtained, and in which the carrier comprises water, oxidizer, or other compounds.
A further object of the invention is to provide a fuel mixture for internal combustion engines or burners, by using series-connected microaerosol generators of the carrier substance, water or oxidizer, and subsequently fuel.
These objects and other advantages are accomplished by the carburetor and method as described herein, in which the carrier for the fuel, high degree of atomization and homogeneity of the mixture improve the burning process of the fuel and maximizes the power of the internal combustion engine or burner.
Applying the technique of aerosol production enables an ideal mixture to be approached. Since the life time of microaerosol particles exceeds considerably the duration of time required to introduce the fuel mixture into the cylinder of the engine up to the moment of ignition, the microaerosol mixture remains homogeneous. A mixture of finely atomized fuel and air exhibits all desirable characteristics such as high homogeneity, high total surface area, low combustion temperature, less knocking tendency, high volumetric efficiency and uniform distribution of the mixture, resulting in higher performance of the engine. As a result of the uniform distribution of the fuel and oxidizer obtained by the described method, the combustion mixture is characterized by a high degree of homogeneity of the particles and by the optimum ratio of the fuel film to the carrier core of the particle. This implies optimal conditions for the dynamics of combustion of the fuel mixture.
The microaerosol carburetor of the invention produces particles having a small size in the range of from about 1 x 10⁻⁶ to about 5 x 10⁻⁸m. Additionally, the sedimentation rate coefficient is below 1. The high number (over billions of particles per ml of solution) and the great total surface area imply a significant increase in the efficiency of the engine working with the herein described mode of carburetion of the fuel mixture as compared to a conventional atomization. The carburetor of the invention comprises series-connected microaerosol generators which produce microaerosol particles of a carrier and fuel, with the fuel forming a layer or film on cores of the carrier substance. The series-connected generators of the invention may be pressure driven, for example, as described more fully hereinafter, and may be of any suitable type.

BRIEF DESCRIPTION OF THE DRAWINGS

Advantages of this invention will appear in the following description and appended claims, reference being made to the accompanying drawings forming a part of the specification, and wherein like reference characters designate like parts throughout the several views.

Figure 1 is a somewhat schematic cross-sectional view of a preferred embodiment of carburetor according to the invention;
Figure 2 is a schematic circuit diagram of an electronic control device for maintaining the optimal water content in the fuel mixture; and
Figures 3a and 3b present graphic representations of the combustion dynamics of the fuel mixture produced by a carburetor according to the invention (upper record on Fig. 3a) as compared to conventional fuel dispersion (lower curve on Fig. 3a) and with increasing concentrations of water in the mixture (Fig. 3b).

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring more specifically to the drawings, a preferred embodiment of carburetor according to the invention is indicated generally at 10 in figure 1 and comprises first and second series-connected microaerosol generators G₁ and G₂ for producing a microaerosol of the carrier (water) and the fuel.
The constructional materials and dimensions of the carburetor depend upon the particular requirements of the use to which the carburetor is put. In the particular example chosen, the carburetor operates by positive pressure derived from a suitable source such as a compressor or the like, not shown. In operation, air under pressure is introduced through nozzle or jet 11 and into venturi 12, drawing water up from the reservoir defined in housing 13.
Water is supplied to the reservoir through an inlet 14 from a suitable source, not shown. Due to the action of the venturi, microaerosol particles of water are produced and are then dispersed and subjected to the action of the perforated upper cylindrical section 15 of the venturi housing. These particles of water are caused to impact many times against the perforated housing and upon passing through the perforations 16, are caused to impact against the cylindrical baffle 17, further breaking up the particles. Larger particles fall down into the reservoir and are again drawn into the venturi by the action caused by the flow of air through it. Smaller, microaerosol particles pass upwardly into a second nozzle or jet 18, comprising a part of the second microaerosol generator.
The microaerosol particles of water flow through a second venturi 19 after exiting the jet 18, pulling liquid fuel into the venturi from fuel reservoir 20 defined in housing 21. Liquid fuel is supplied to the reservoir from a suitable source, not shown, via an inlet 22. The pressure difference generated in the venturi causes the fuel to break up into microaerosol particles which form a film or layer on the water particles. The resultant water-fuel mixture is homogenous, uniformly dispersed and very finely atomized. The resultant microaerosol mixture is then passed through perforations 23 in cylindrical housing 24, impacting many times against the walls of the housing resulting in further break-up of the particles of water and fuel. Upon passing through the perforations, the particles strike cylindrical wall 25. Droplets and larger particles fall back down into the reservoir for recycling through the venturi. The smaller water-fuel microaerosol particles in air pass upwardly through an outlet 26 from which the mixture is directed to a burner or to the combustion chamber of an internal combustion engine.
The pressure difference across the jets 11, 18 and the outlet 26 causes the fuel and water to be drawn into the venturi and is broken up into small particles. The series connection of the generators results in forming a fuel film on the water particles.
An additional inlet 27 is provided into the water reservoir 13 for adding of the fuel, or various compounds and an inlet 28 is provided into the fuel reservoir 20 for adding a fuel-water emulsion or other substances to the microaerosol generator G₂.
The ratio between water and fuel, as well as the respective composition of the water-fuel microaerosol in air are determined by the size of the generator chambers and the amounts of liquids supplied as well as by the developed head pressure across the air jet 11 and outlet 26. These values are determined by the given constructional demands of the burner or engine. The concentration ratio of the fuel to air of the mixture can also be regulated by using an air C₁ and mixture C₂ containers connected through respective valves with said microaerosol generator.
The optimal level of water in the fuel mixture in conditions of various air humidity is controlled by means of any type of humidity sensitive apparatus, such as that shown in Fig. 2. The control system shown in figure 1 at 29 comprises a generator G of electrical oscillations, which, in the simplest case, may be the engine alternator or electrical power line supplying AC oscillations. The signal from the generator is then brought to bridge B which contains a humidity transducer C with thermistor T. From the bridge a signal is forwarded to differential amplifier D, and to power transistors P, from which the resultant signal through coil M operates a needle valve N to control flow of water W from a suitable source to the water inlet 14 or, respectively, 38, of the microaerosol generators.
The dielectric constant of the capacity transducer C undergoes changes according to the actual humidity of air and, respectively, alters the amplitude of oscillations in the bridge. The voltage difference is amplified by the differential amplifier D and finally by the two push-pull power transistors P. The position of the needle N in the tube is determined by the electromagnetic field between coils M.
The particular construction requirements and operation conditions of the engine or burner decide the accuracy of the control device 29.
A hybrid active-passive mode of operation of the described carburetor is possible. The carburetor of the invention may operate synchronously and in dependence on the engine, or independently, driven by a separate compressor, as in the case of a turbo-charged engine.
In the case of reaction type engines, the microaerosol generators described herein operate with water, fuel and a respective oxidizer combined in series, regardless of the type of generator used. However, the pressure-driven generators described are the simplest. A plurality of series-connected microaerosol generators of fuel, water and oxidizer may be arranged in parallel if necessary, particularly for jet-type internal combustion engines.
The fuel mixture prepared according to the invention has an extremely high degree of dispersion (to a fraction of 1 m), a very high total surface area of the particles, a uniform and homogeneous mixture of the carrier fuel particles; a low sedimentation rate coefficient of particles carrying static charge enables the mixture to be fully evaporated or subjected to compression without coalescence of constituent particles of the mixture and subsequently introduced into the burner or engine. The prepared mixture may be injected to the combustion chamber.
The greater total surface area of the liquid phase of the fuel and the high degree of homogeneity of the microaerosol particles according to the described method as compared to the conventionally dispersed fuel droplets result in a significant increase in the efficiency of the engine. The power increase of the engine is due to a considerable enhancement of the developed pressure change (dp/dt, where p-pressure and t-time) during combustion of the microaerosol fuel mixture, and to an acceleration of the first phase of the combustion of the mixture.
Testing of the dynamics of combustion of the microaerosol water-fuel mixture produced in accordance with the invention from both leaded and unleaded fuels, showed that the advantages apply to both types of fuels. These advantages achieved with the carburetor of the invention include significant lowering of combustion pollutants such as hydrocarbons, carbon monoxide, nitric oxides, and the like. The conversion of carbon monoxide to carbon dioxide, due to the presence of water in the mixture, results in the production of some amount of burnable hydrogen:
CO + H₂O = CO₂ + H₂.
Other advantages of the described type of carburetor include the following: lower combustion temperature of the microaerosol mixture, lower combustion of lubricating oil and anti-knock features (greater solubility of anti-detonants in water than in gasoline).
The optimal content of water in the fuel mixture (Fig. 3b) with preservation of the optimal gasoline/air ratio in the described carburetion is possible and independent of the work conditions of the engine. This results especially in considerable power increase in the use of high gasoline content of the mixture. The invention permits an elimination of some of the auxiliary elements of contemporary carburetor. The carburetor of the invention controls the power of the engine only by means of the amount and concentration of the fuel mixture supplied thereto.
The feature of the described process of carburetion by means of series-connected generators of microaerosol particles of water, fuel and oxidizer may be especially valuable where the moisture content of ambient air is very low - such as at high altitude or in desert conditions or in cold climate.
If the air has a very high relative humidity, water need not be added in the carburetor of the invention. This does not detract from the other advantages of the invention resulting from the atomization of the fuel. In this case operates only the second-step generator, or simply in such case the carburetor is provided with only one generator.
The described method and carburetor enable also production of a dual fuel mixtures. For instance, heavy evaporating fuel can be introduced to the first-step generator wherein it is converted to carrier microparticles, covered subsequently in the second-step generator by other type of fuel.

Claims

1. The method of producing a fuel mixture , comprising the steps of:
atomizing a carrier substance in a first-step microaerosol generator to produce microaerosol particles thereof having a particle size in the range of from about 1 x 10⁻⁶m to about 5 x 10⁻⁸m;
atomizing fuel in a second-step microaerosol generator causing all of the atomized carrier substance to flow through said second-step microaerosol generator to entrain said atomized fuel; and
covering the carrier substance particles with a fuel film when the carrier particles and fuel pass through the second-step microaerosol generator, thereby producing a homogeneous mixture consisting of particles of carrier substance with a fuel film thereon.

2. The method as claimed in claim 1, wherein the carrier substance is water, oxidizer, or other compounds in the liquid, or gaseous phase or dispersion of solid particles.

3. A carburetor, as claimed in claim 1, for producing a microaerosol fuel mixture, comprising:
a housing having first- and second-step series-connected microaerosol generators therein;
said microaerosol generators each including labyrinth passage means for precluding flowing through of particles having a size greater than a predetermined range;

4. A carburetor for producing a microaerosol fuel mixture comprising one fuel microaerosol generator, two in series-connected microaerosol generators or a parallel setup of in series-connected generators of the carrier substance and fuel, wherein said generators as claimed in claim 3, are any type of microaerosol generators such as cascade, ultrasonic, jet, turbo, and other types.

5. Said generators, as claimed in claim 3, of the carrier and fuel substances operate under positive pressure,
wherein an air inlet nozzle and venturi of the first-step generator is under positive pressure supplied by a separate compressor and its outlet is connected subsequently with a respective nozzle and venturi of the second-step generator, or by a negative pressure,
wherein the outlet of the second-step generator is connected with the source of negative pressure produced in the combustion chamber or cylinder, and the nozzle and venturi of the generator are connected with the outlet of the respective first-step generator, or by ultrasonic jet or turbo generators,
wherein the outlet of the first-step generator is connected to the inlet of the second-step generator.

6. A carburetor, as claimed in claim 3, producing fuel mixture during operation of the engine or independently driven by a separate compressor with additional container for prepared mixture or in combination of both.

7. A carburetor as claimed in claim 3, wherein the produced composition of the produced fuel mixture is determined by the size and performance capacity of the first and the second-step generators.

8. A carburetor as claimed in claim 3, wherein control means are connected with the means supplying water for controlling the amount of water supplied in response to ambient humidity.

9. A carburetor as claimed in claim 3, wherein the produced fuel mixture is then forwarded to a combustion chamber (cylinder) instantly during operation of the engine, or injected periodically or continously to the combustion chamber.

10. A carburetor as claimed in claim 3, consisting of said generators and parallel means comprising containers and conduits for air and produced fuel mixture or additional substances.