BACKGROUND OF THE INVENTION
The present invention relates to an exhaust gas purification system in a combustion engine and more particularly to an exhaust gas purification system in an internal combustion engine typified by a diesel engine, which suppresses the generation of noxious nitrogen oxides, sulfuric oxides, unburned carbon particles such as soots contained in exhaust gases produced as a result of combustion of fossil fuels.
While the fossil fuels typified by petroleum has brought about an industrial revolution after coal to the human society to make human lives affluent, it is also known that the earth's environment is now subject to a drastic change. The exhaused gases produced by combus-tion of fossil fuels, more particularly, petroleum oil fuels familier to us contain a huge amount of noxious nitrogen oxides, sulfuric oxides, unburned carbon parti-cles such as soots to endanger the existence of animals and plants. Particularly, nitrogen oxides discharged from automobiles are responsible for 70 % of such ex-haust gases so that it is impossible to forestall the pollution of the earth's environment without solving this problem.
In order to solve the above problem, various meas-ures have so far been proposed to cope with the exhaustgases: a process to suppre6s the generation of noxious components after the combustion of the fuel by removing, in the process of purification, components such as sulphur which can become a noxious component after combustion from the contents of the fuel; an approach by improving an engine itself as opposed to the improvement of the fuel, particularly a rarefied combustion proces6 which maintains the combustion temperature lower than the conventional diesel engine to suppres6 the genera-tion of nitrogen oxides; and an exhaust gas treatment to make the molecular structure steady by use of catalysts before discharging the combustion exhaust gas into the air.
Of those measures are included Japanese Pat. Appln.
Kokai Pub. No. 2-119921 and No. 2-103920 which relate to purification of the exhaust gas in the proces6 of being exhausted into the air.
A prior art example of the rarefied combustion method is disclosed in Japanese Pat. Appln. Kokai Pub.
No. 3-134236 as the method of preventing the nitrogen oxides, hydrocarbons or carbon monoxide fro being gener-ated by controlling an air-fuel ratio.
As far as nitrogen oxides are concerned, it i6 con ceived of that ammonia is subjected to thermal decompo-216223~
sition to form NH2 which is further mixed with the exhaust gas for reduction thereof. However, ammonia is needed to be carried by the automobile for this purpose which is not practical as a purifier for an automotive use.
The method of removing sulpher in advance in the process of purification of the fuel can be classified as a preferable measure in view of supplying clean fuels though it lacks the likelyhood of immediate effects in the present imminent environmental situation and has a problem that accomplishment of the purpose seems too time-consuming for an emmergency measure to solve the exhaust gas problem.
On the other hand, the exhaust gas treatment by adding other substances or involving chemical reactions with the use of catalysts are in need of some heavy-duty facilities which may be suited to the exhaust gas puri-fication facilities in plants but not to automotive purposes. Further, while the rarefied combustion method well prevents the production of nitrogen oxides by controlling the combustion in the rarefied air-fuel ratio to suppress the rise of combution temperatures, there is another problem of the reduced combustion power to lower the torque of the engine output.
This forces the users to reduce the payloads of - '~16223 7 freight cars to cope with the lowered output thereof, thus involving another unfavorable problem of the rise of transportation costs.
SUMMARY OF THE INVENTION
In order to cope with the exhaust gas problems with out lowering the automotive payload, a heavy duty engine is in demand. This means that while freight cars equipped with the heavy duty engine to obtain a high power may solve the problem of trasportation costs, the amount of exhaust gas increases with such high exhaust gas emission, creating the problem of increased noxious substances in absolute terms.
It is, therefore, an object of the present invention to provide a system which is capable of purifying the exhaust gas by means of system other than the rarefied combustion method of exhaust gas treatment with cata-lysts.
In order to accomplish the aforementioned object, the present invention provides, in one aspect, an ex-haust gas purification system comprising a fuel supply system for a liquid fuel, metal coil means accommodated in said fuel supply system for activating kinetic movement of molecules of said liquid fuel, whereby the liquid fuel passing therethrough contacts said metal ~62237 coil means to be activated such that said fuel are atomized into parcles having an increased jetting power.
In another aspect, the invention provides an exhaust gas purification system comprising a fuel supply system for a-liquid fuel, metal coil means accommodated in said fuel supply system for electrically charging molecules of said liquid fuel, whereby the liquid fuel passing through an extra narrow gap in the fuel supply system at a high speed is electrically charged, said liquid fuel being jetted into a high pressure high temperature atmosphere to discharge electricity for ignition there-of.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is an explanatory sectional figure of the fuel supply system incorporating the present invention;
Fig. 2 is an exploded view of the jet nozzle partly in cross section;
Fig. 3 is a perspective view of the metal coil means in a disassembled state thereof in one embodiment of the present invention;
Fig. 4 is a perspective view of the metal coil means in another embodiment used in place of the metal coil means used in the embodiment of Fig. 3;
Fig. 5 is a cross sectinal view of a further modi-2 ~ 7 fication of the metal coil means;
Fig. 6 is a cross sectional view of a still furthermodification of the metal coil means;
Fig. 7 is a cross sectional view of a state in which the attachment of said metal coil means is shown in a still further embodiment; and Fig. 8 is a cross sectional view of a still further embodiment of the invention which is incorporated in the jet nozzle.
Descri~tion of the Preferred Embodiments Hereinafter, embodiments of the present invention will be explained referring to Figs. 1 through 8 at-tached hereto. In the figures, numeral 1 designates a feed pump, by means of which the fuel from the fuel tank is supplied by way of filter 2 to plunger 3. Delivery valve 4 is opened by the delivery power of said plunger 3 so that the fuel is further admitted to jet nozzle 5 to jet out the fuel into the cylinder to complete the fuel supply system.
The passage leading from feed pump 1 to jet nozzle 5 constitutes the fuel supply system in which spiral tube 60 is accommodated in jet nozzle 5 as a means of acti-vating the fuel which will be explained in detail.
Spiral tube 60 ring is accommodated in a space de ~162237 fined in fuel pocket 52 formed in nozzle body 51 which constitutes jet nozzle 5. Since said fuel pocket 52 is in the form of annular groove space, spiral tube 60 is of annular shape, said spiral tube being formed to have an equal or less circumferential size and an equal or width to said fuel pocket 52; that is, sizes permitting engagement thereof within the space in fuel pocket 52 or the maximum sizes permitting accommodation thereof in said groove space are selected.
Said jet nozzle 5 has needle 54 accommodated in a space centrally formed within said nozzle body 51 or in so-called needle guide 53, said fuel being supplied to pocket 56 near the jet exit by way of three supply passages 55 which provide communication between said fuel pocket 52 and fuel pocket 56 such that the prede-termined fuel is jetted into the cylinder when the neelde opens valve seat 57.
Further, a spiral tube ring or composite coil member 60 (hereinafter referred to as "tube ring") formed by winding metal wires into a hollow spiral configuration is nested into said fuel pocket 52 of an annular groove configuration. More specifically, said spiral tube ring 60 is formed by inserting a coil member or counterclock-wise spiral tube 62 into the inside of a coil member or clockwise spiral tube 61 of a slightly larger inside - ~152~37 diameter than said countercloskwise spiral tube 62 and then connecting the free ends of said clockwise spiral tube 61. The winding directions of said spiral tube 61 and said spiral tube 62 are preferably opposite. If unavoidable, however, spiral tubes of the identical winding directions may be used. Further, spiral tube 62 may be omitted in view of a size requirement while a further spiral tube may further be inserted into said spiral tube 62.
It is observed that if copper o~ides (CuO, Cu2O), iron (Fe), nickel (Ni), cobalt (Co) or gold (Au) is used as a material for tube ring 60, a light oil fuel iB preheated under the jet pump pressure of 100 to 300 kg/cm and further heated in the reductive atmosphere with the result that the fuel is activated by some action of said metals.
In this instance, the light oil is transformed into a short molecular structure to accelerate the combustion speed of the fuel after the jetting into the cylinder.
Further, said fuel is passed through a constricted gap at a high speed to be charged with static electricity.
By being admitted into the cylinder at one blast, the fuel discharges electricity to make the ignition speed faster, thus supressing the generation of fuel cinders.
The inside of the cylinder is by nature under high ~16~23~
temperature/ high pressure condition so that the the jetting of the charged fuel thereinto remarkably im-proves its ignition performance to speed up the igni-tion. In addition, the high speed passing of the fuel through the gap in tube ring 60 causes the same to vibrate at a high frequency to accelerate a further activation of the fuel molecules.
While the space in fuel pocket 52 is shown as a location to accommodate said spiral tube ring 60 in the above explanation, a member separate from nozzle body 51 in the form of distance piece 58 having fuel pocket 59 therein may be used. Selection of the location may be determined in accordance with various factors such as the assemblage easiness, the engine capacity, etc.
Further, said tube spiral tube ring 60 so far ex-plained may be replaced with a dought-nut shaped coil formed by continuously wining a length of wire into a single coil so that it is accommodated in either one of fuel pockets 52 and 59 or in both thereof. In this embodiment, the piercing power and the ignition perform-ance are not inferior to the previous embodiment.
While the processes leading to the results are not clear enough in the foregoing embodiments, it is rea-soned that part of the light oil is transformed into a short molecular structure with the result that when the ~1622~7 nozzle is opened, the light oil components in the fuel is jetted into the cylinder in the form of methane/butane gas to be burned therein under the above mentioned combustion conditions to accomplishing a practically perfect combustion. This is due to turbu-lence in the latter half phase of combustion discussed by a number of researchers, said turbulence reducing the eneration of nitrogen oxides and smoke together with the cutdown of fuel consumption.
The 10 mode value of a vehicle loaded with the system of the present invention recorded 0.53g., meeting the target NOX emission standard of 0.6g per 1 km trav-elling distance in the light-weight vehicle section (body weight less than 1.7 tons) provided for in the 1993 version of the emission standard regulation laid down by the Environmental Agency (test results measure-ment conducted by Japan Automobile Transportation Engi-neering Society).
While the embodiments in which tube rings 60 are accommodated in fuel pocket 52 and/or fuel pocket 59 in are shown in the forgoing explanations, a coil member or spiral tube 70 of metal material similar to a thin tube may be accommodated in the supply passage 55 of nozzle body 51. In such type, tube 70 inserted into supply passage 55 iB secured at opposite ends 71 thereof to the - ~16223~
ends of the supply passage 55.
Alternatively, said tube 70 may be accommodated in supply passage 59a formed in distance piece 58.
Said tube 70 may be of circular cross section, irregular ellipse cross section containing straight portions or triangular cross section containing rounded angle portions for shaping convenience or counter-emis-sion purposes.
Further, favorable results are obtained if such tubes are accommodated in supply passages 55 and 59a at an angle with respect to the axis thereof as opposed to axially parallelly. This is presumably due to said spiral tube 70 being subject to twist as the fuel pas-sages the gap in spiral tube 70 such that the piercing power within the cylinder is increased.
As clearly explained in the foregoing, a perfect mixture of the fuel and the air is obtained while the fuel is evenly dispersed within the cylinder under high pressure to achieve a practically perfect combustion.
Therefore, an output of conventional level is obtained with a small amount of fuel so that the fuel consumption is maintained low to assure that the generation of nitrogen oxides is suppressed in a mimimum amount. In the diesel engine, it is possible to suppress the gener-ation of black smoke, vibration, noise, etc.
So far, explanations are given in connection with the diesel engine, it is needless to say that the present invention is applicable to the burner of a combustion furnace or the burner of a boiler not to mention a gasoline engine. Further, a spiral tube fomred by winding a mesh material may be adopted in place of a spiral tube formed by metal wire. Further, a similar result is expected o~ a material perforated through an etching process not to mention the mesh material.
According to the present invention, it is possible to atomize the fuel into particles during the supply process of the liquid fuel into the combustion engine.
It is also possible to supply a fuel having a strong jetting power under high pressure such that perfect combustion as well as an even combustion is made possi-ble to suppress the generation of nitrogen oxides, sulfuric oxides and soots. Further, static electricity is discharged from the fuel charged therewith such that the fuel is ignited immediately after being jetted.
Thus, the present invention is useful in that all these achieved performances contributes to preventing the pollution of the environment while the engine outputs are improved without the generation of vibration, black smoke, noise, etc.