US2704659A - fuchs - Google Patents

Description

G w FUCHS 2,704,659

A. APPARATUS FOR MIXING, ATOMIZING AND PARTIALLY GASIFYING FLUID MATERIALS March 22, 1955 Filed May 19, 1950 2 shee ts-snet 1 FIG! INIfENTOR. Armin Fuchs ATTORNEY March 22, 1955 A. G. w. FUCHS 2,704,659

APPARATUS FOR MIXING, ATOMIZING AND PARTIALLY GASIFYING FLUID MATERIALS Filed May 19, 1950 2 Sheets-Sheet 2 {I l5 7 l8 3 28 -5 l9 -1; l7 8 l4 FIG.2

INVENTOR.

Armin Fuchs ATTORNEY United States Patent APPARATUS FOR MIXING, ATOMIZING AND PARTIALLY GASIFYING FLUID MATERIALS Armin G. W. Fuchs, Karlsruhe-Durlach, Germany Application May 19, 1950, Serial No. 162,836

Claims priority, application Germany October 22, 1949 4 Claims. (Cl. 261-75) This invention relates to an improved method for mixing, atomizing and partially gasifying aeriform materials together with fluid fuels.

More particularly the invention relates to a method of producing improved mixtures of this kind comprising aeriform material and liquid fuel, as light oil, gasoline, etc., for combustion motors, internal combustion engines, etc.

The invention also relates to a new apparatus especially adapted to perform the inventors new method for producing his new fuel mixtures.

In the heretofore known devices of this kind generally designated as carburetors, the fuel is fed from a fuel tank via a main nozzle into a sort of pre-mixing chamber in which the fluid fuel is mixed with air which also enters the pre-mixing chamber via cylindrical ringchannels and valve controlled inlets. This pre-mixing chamber is usually connected with the air funnel by nozzle-like apertures through which the main air stream proceeds to the combustion chambers or cylinders. This known device serves primarily the purpose to mix intimately the fluid fuel with air before it enters the air funnnel in order to form a foam.

It is a well-known fact that this familiar apparatus is unsuccessful in achieving a fairly satisfactory air-fuel mixture. Only a mixture with more or less finely dis persed fuel particles is obtained which will not be completely consumed in the combustion chamber. Consequently, a comparatively great reduction of efliciency (as compared with the efliciency theoretically achievable) and a relatively large fuel consumption results. Moreover, the incomplete combustion entails greater wear of the machine, inasmuch as the unconsumed fuel particles attack the lubricating film in the cylinders and wash it off. Finally, the unconsumed particles also penetrate the lubricating oil, whereby dilution and decomposition of the lubricating oil with detrimental effects on the whole machine is effected.

The inventor has found by considerable study and experimentation that two circumstances essentially cause these phenomena, which are casually connected and mutually influence each other. The fuel-air mixture proceeds from the ejector nozzle or nozzles of the carburetor in the form of a jet into the air funnel and thus into the main air stream, Where the mixture jet, as a result of the usual upward slant of the ejector nozzles, is first thrown against the inner walls of the air funnel and then carried away by the main air stream. In this process a considerable further and more intensive intermingling of the mixture does not take place, aside from the mere addition of the main stream.

Through such exit of the fuel-foam (which is the form of the fuel-air mixture at this stage) from the ejector nozzle or nozzles, a zone of turbulence is also caused which to a certain extent indeed supports the mixing of the mixture but which, on the other hand, results in a very undesirable effect, namely that the mixture reverts again to larger aggregates, or, in other words, that the mixture, within certain bounds, is again un-mixed. This undesirable efiect is, moreover, furthered by the practically unavoidable cooling of the mixture at the outer surfaces of the carburetor (condensation effect).

Essentially, therefore, the problem is to mix more intimately, in the air funnel, the fuel-air mixture coming out of the ejector nozzles and/or to effectively support this mixing by suitable means so that atomization in smallest particles and even a partial gasification occurs,

2,704,659 Patented Mar. 22, 1955 and at the same time to preclude the tendency and the possibility that the fuel-air mixture, which has been mixed in finest particles, atomized, and partially gasified, revert again to larger aggregates.

Thorough tests and consideration have shown that a considerably more permanent and intimate mixture and atomization, as well as a partial gasification of the mixture coming out of the ejector nozzles, is achieved by passing the mixture stream over sharp-edged surfaces which interrupt the flow. In this process, the mixture does not come to rest, but, in its further flow, encounters further sharp-edged surfaces which again interrupt it. Thereby the mixture is given a certain direction and it flows in concentric cylindrical sections.

To a certain extent this process also prevents a reversion of the mixture to larger aggregates, which reversion is, however, practically completely inhibited only if one can prevent major turbulence of the flow by regulating said flow according to aerodynamic principles. The fuel-air mixture then flows, on the whole as well as in the individual interruption phases, in such a manner that, on the one hand, the mixing, atomizing, and partial gasification is furthered by the repeated interruptions, and, on the other hand, undesirable turbulence in the air funnel, which might lead to un-mixing of the mixture, is precluded.

In accordance with this invention, the fuel-air mixture or fuel-air foam is prepared in a pre-mixing chamber in the well-known manner and introduced into the air funnel to be atomized and partially gasified, after the addition of the main air stream, by passing the mixture stream over sharp-edged surfaces at which it is repeatedly interrupted and prevented from re-uniting to larger aggregates by having the repeatedly interrupted mixture stream flow, according to aerodynamic principles, without appreciable turbulence, in concentric mixture cylinders the diameters of which become smaller in the direction of flow.

In my new device for carrying out this method, the repeated interruption of the mixture stream is achieved by sharp-edged rings arranged over or under each other in the direction of flow, while the reversion of the mixture to larger aggregates is prevented by a body formed according to aerodynamic principles and arranged above and below in the direction of flow of the mixture stream. Said body may, for instance, be in the form of a drop with its tail-end pointing down stream. Preferably, one of the ring surfaces is formed by a surface conical or otherwise bent in the direction of flow of the mixture, its exterior edge having sharp cutting-edges.

According to whether the carburetor is pump or gravity fed, the drop-shaped body, or head, is introduced above or below the above-mentioned ring surfaces in the direction of flow of the mixture, and may be com bined with said ring surface to form a single unit. Said body has a plurality of curved ring surfaces, which, seen from the side, are similar to saw-blades, their sharp edges, seen in the direction of flow, becoming smaller in diameter and forming concentric rings when viewed from the point of the body.

The ring surfaces of said body exhibit different angles of incidence to the horizontal plane which are preferably variable in the direction of flow of the mixture and the angle of incidence can be made to increase towards the point of the drop-shaped body. The size of the angle of incidence results in a correspondingly greater or lesser interruptive effect on the part of the ring surfaces. One can alter the mixing and atomizing effect of the sharp-edged surfaces as desired by suitable selection and variation of the angle of incidence as well as of the variable extent to which the ring surfaces extend above the kern of the drop-shaped body. Hereby, the greater the angle of incidence is, the less is the interruptive eflfect of the ring surfaces and vice versa, whereas the interruptive effect is greater, the further the ring surfaces extend above the kern of the drop-shaped body, and vice versa.

Preferably, one ring surface and the drop-shaped body are connected with a piece of pipe which forms the premixing chamber and which is provided with slanting bored holes or can be made in one piece with it, the lower end being capable of being screwed on to a pipe flange of the carburetor case. On this pipe flange is set a cylindrical jacket of greater diameter than the pipe section forming the pre-mixing chamber, bored at the upper end and forming a ring-chamber with the pipe section. On the upper end of the cylindrical jacket a cap is placed which is open at the bottom and likewise of larger diameter and which, in turn, together with the cylindrical jacket forms a ring chamber interconnected with the above-mentioned inner ring chamber. Finally, the upper part of the pipe section forming the pre-mixing chamber has a ring flange of any desired form whose lower bearing surfaces rest against the upper surface of the closing cap. Above or in the ring flange, borings are provided which connect the pre-mixing chamber with the air funnel.

In this manner a pre-mixing chamber of the commonly known type is achieved, whose construction parts consist of the simplest elements which are easily combined, and which is essential and cheap for mass-production and facilitates servicing.

Preferably the interior chambers of the device, in particular the air funnel, are given an aerodynamically advantageous form, whereby the latter, for instance, can consist of several parts easily interchangeable with others of different shape. By this means as well, one can influence the course of the mixture stream and thus the mixing and atomizing effect. In the case of pump-fed carburetors, the device or devices for foaming the mixture may be arranged inside or outside the air funnel, whereas in the case of gravity fed carburetors the device or devices for foaming the mixture must be arranged outside the air funnel.

In the drawing:

Figure 1 is a vertical section through a carburetor according to this invention;

Fig. 2 is a vertical section through another embodiment of a carburetor according to this invention. Similar numerals refer to similar parts in both figures.

The carburetor case is represented only schematically. All details have been left out or merely indicated.

It consists of a plurality of easily assembled parts, as, for instance, the upper part 1, the middle parts 2 and 3, the air suction tube 4. and the float case with the cover 6. The interior of the carburetor case including the ingress and egress connections and particularly the air funnel 7 are preferably shaped according to aerodvnamic principles in order that the flow of the fuelair mixture may proceed as smoothlv as possible. The air funnel 7 mav consist of a plurality of parts which can be connected with the middle part 3 of the case by screwing or other means. In that all or individual parts of the air funnel may easily be exchanged for parts of a different form, account may be taken of whatever conditi ns may prevail in the air funnel 7 also. In the embodiments shown in the drawings, the main fuel nozzle 9 is arranged between the suction elbow 4 and the float casing 5 on the one hand and the s ace 8 of casing part 3 in su h a manner that the main fuel nozzle 9 is easily accessib e from the outside and can be rep aced at anv time. To this e d it is necessary onl to loosen Screw 10, whereupon the nozzle 9 can be easily removed. The foaming device is situated in space 8. It consists of a cvlinder jacket 11 which rests on a ring or i e flange 12 of casing part 3, a gasket intervening which is only indicated on the drawing. Concentric with the cylinder jacket 11. but of smaller diameter. a pipe section is arranged which may be screwed into the ring or pipe flange 12. At the upper end of pipe section 14 the headpiece 13 is connected or made of one piece with it. On the cylinder jacket 11 a cylindrical cap 16 is provided. The cylinder jacket 11 forms with pipe section 14 the ring chamber 19, and the cap 16 with cylinder jacket 11 forms the ring chamber 21. The ring chambers 19 and 21 are interconnected by the apertures 20 to be found at upper end of cylinder jacket 11. In pipe section 14 there are furthermore, in the vertical and horizontal plane, nozzle-like apertures 17 which, in the horizontal plane or slanting upward, may run radially or partly tangentially. The inner chamber 18 of the pro-mixing and foaming chamber is thus in connection with the outer atmosphere via the apertures 17, the ring chamber 19, the borings 20 and the ring chamber 21. Between the head-like body 13 and the upper end of pipe section 14 is a flange-like thickening 15 whose lower surfaces lie against the upper surface of the cap 16. When, therefore, the pipe section 14 is screwed into the pipe flange 12, the pre-mixing chamber consisting of the parts 11, 13, 14, and 16 is held together by the ring flange 15. In the ring flange 15 or head 13 are nozzle-like apertures 22 which connect the chamber 18 of the pro-mixing chamber with the air funnel 7.

The head-like body 13 exhibits, according to Fig. 1 a ring surface 24, conical or otherwise curved in the direction of discharge whose outer edges come to a sharp edge. Above this ring surface 24, other ring surfaces 26 are provided in the head-like body 13. Ring surface 24 can also, as shown in Fig. 2, be combined with the head-like body 13 in one piece. The ring surfaces 26, seen in vertical longitudinal section are saw-like, and, seen from above are of decreasing diameter towards the point of the head-like body 13. The exterior edges of these surfaces 26 are also sharp-edged. The head-like body 13 is preferably of aerodynamic shape, as dropshaped, with the point in the direction of discharge of the mixture.

The ring surfaces, as shown in the left half of Fig. 2, may be level, or, as shown in the right half of Fig. 2, be at an angle to the horizontal. This angle a is termed angle of incidence. This angle a is variable, i. e. it may be different in the various ring surfaces arranged one above the other. Preferably the angle of incidence a increases towards the point of the drop-shaped body 13. The amount to which the ring surfaces 26 extend over the core of body 13 is also variable and preferably decreases towards the point of body 13.

Reference numeral 27 designates the idling valve, 28 the idlling channel, and 29 the main valve, 30 the throttle va ve.

In so-called up-stream carburetors, as shown in Figs. 1 and 2, the pre-mixing chamber 18 can be arranged in space 8 or outside it. If there are a plurality of premixing chambers, they may be arranged partly inside and partly outside space 8.

In the case of gravitv-fed carburetors. the pre-mixing chamber or chambers 18 must be arranged outside space 8 as they would otherwise hinder the discharge of the mixture.

In carrying out my invention, the operation of the pertinent devices described above is as follows:

At rest. the fuel goes from the float case 6 via the main valve 9, 29. to space 18 and through the aperture 17 into the ring chamber 19. In all these chambers the level of the fluid seeks that of the float case. When the throttle valve 30 is opened, atmospheric air streams into chamber 8. passing the head-like bodv 13 throu h air funnel 7 and into the combustion chamber or chambers. As a result of this air stream there arises below the ring surface 24 and/or the head-like body 13 a ring-shaped vacuum which sucks the already foamed fuel-air mixture in chamber 18 via borings 22. Through the exhaustion of the fuel-air mixture out of the chamber 18 and because the fuel cannot flow quickly enough out of the float-case, a certain partial vacuum also arises in chamber 18 which sucks in. via boring 17, the inner ring chamber 19. the boring 20, and the outside ring chamber 21, atmospheric air. This suction is aided by the air stream from tube 4 which sweeps the device. The air thus sucked in proceeds, as already described, via ring chamber 21 and bore-holes 20 into the ring chamber 19, there breaks through the surface of the fuel and goes, via the bore-holes 17 into the pre-mixing chamber 18, Where, as a result of the comparatively small bore-holes 17, it reaches the fuel in comparatively fine dispersion, mixes with it and causes it to foam. The thus formed mixture of fuel and air is foamy and proceeds, in this condition, through the valve-like aperture 22 into the air funnel 7, where it is taken up by the main air. A further considerable mixing, aside from the addition of the main air does not take place in the air funnel 7, so that the mixture reaches the combustion chambers with more or less finely divided fuel particles.

In order, however, to enhance the mixing of the fuel-air mixture issuing from the nozzles 22 in the air funnel 7 and in order to achieve maximum atomization and partial gasification of the mixture, the mixture is now passed over the sharp-edged ring surfaces 24, 26, where it is again and again interrupted in its flow. By this constant interruption, the mixture is further mixed, atomized and partly gasified. Moreover, this constant interruption of the mixed stream imparts to it a certain direction towards the throttle valve 30 as the mixture, in the various interruption phases, discharges through quasi ring-shaped mixture cylinders of ever decreasing diameter. Thus, there arises, in this zone (which usually exhibits strong turbulence) a certain steadiness of flow which prevents turbulence and the undesirable reconcentration of the finely divided mixture particles to larger aggregates. If, as indicated schematically in Fig. 2, the head-like body 13 is shaped according to aerodynamic principles, as in the shape of a tear, the discharge of the fuel-air mixture becomes practically free of turbulence without hindering the mixing through the interruption of the mixture stream at the sharp-edged ring surfaces.

Through the variability of the shape of the head and of the number and shape of the ring surfaces, of the angle of incidence of the ring surfaces and of the amount the ring surfaces protrude over the core of the body 13, it is possible to alter and improve the mixing, atomizing and partial gasification of the mixture so as to achieve the best mixture, whereby the initially mentioned disadvantages of incomplete combustion of the mixture are prevented or at least greatly minimized.

The reduction of fuel consumption achieved with this process and the pertinent apparatus amounts surely and constantly to from 15 to 25 per cent, whereby the output of the machine is increased. This success can be achieved with any motor and any fuel.

Although the invention has been described in connection with specific details of preferred embodiments thereof, it must be understood that such details are not intended to be limitative of the invention except as set forth in the accompanying claims.

Having thus described my invention, I declare that what I claim is:

1. In an apparatus for mixing, atomizing and partially gasifying aeriform materials and fluid fuels of the carburator type, comprising an atomizing chamber including an atomizer and a discharge pipe for the gaseous mixtures outflowing from said atomizer, a body of substantially aerodynamic drop-shape arranged in the center of said discharge pipe, the point of said drop-shaped body pointing in the direction of the flow of said gaseous mixtures and being provided with annular concentrical sharp-edged grooves of saWteeth-like sections, wherein the sharp edges of said grooves point in the direction of the gas-liquid mixture led through said device.

2. The apparatus set forth in claim 1, wherein the lower surfaces of the different projections formed by the grooves provided in said body form different angles from the horizontal.

3. The device set forth in claim 1, wherein the different projections formed by said grooves become smaller in the direction of the point of the body.

4. The apparatus set forth in claim 1, in which the diameter of said annular grooves becomes larger in the flow direction of the gas-liquid mixture.

References Cited in the file of this patent UNITED STATES PATENTS 1,483,634 Guelbaum Feb. 12, 1924 1,510,366 Whiteman Sept. 30, 1924 1,583,692 Kousnetzofl. May 4, 1926 1,656,155 Alexandrescu Jan. 17, 1928 1,929,234 Anderson Oct. 3, 1933 1,934,840 Claudel Nov. 14, 1933 1,949,031 Weber Feb. 27, 1934 2,347,427 Mock et al. Apr. 25, 1944 FOREIGN PATENTS 353,189 Great Britain July 23, 1931

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