US2838362A - Apparatus for atomizing liquids - Google Patents

Description

June 10, 1958 A. A. ROBERT EIAL 2,833,362 I APPARATUS FOR ATOMIZING LIQUIDS Filed Dec. 22, 1 954 fillin illrlvllllvilvlllllil rlllffl I.

INVENTORS ALAN A. ROBERT BY OTHMAR KECKSTEIN ArToRNEYs APPARATUS non ATOMIZING LIQUIDS Alan A. Robert, Los Angeles, Calif., and Othmar Keckstein, Tradate, Italy, assignors to Coachcraft, Ltd, Hollywood, Calif, a corporation of California Application December 22, 1954, Serial No. 476,950

Claims priority, application Germany December 24, 1953 6 Claims. (Cl. 261-83) This invention relates to improvements in apparatus for atomizing liquids, more particularly in which the atomization is effected by the use of a perforated member to which the liquid to be atomized is applied.

It is a known practice to whirl a liquid such as water to be atomized with air in a tank, for example, by means of an aerator and to subsequently force the mixture through perforated walls of the tank. However, in this procedure, the droplets of water forced through the perforations in the wall of the tank are for the most part separated from the air or mixture at the perforated wall, so that such practices and arrangements do not effectively accomplish their intended function of bringing about the atomization of the liquid.

The primary object, therefore, of the present invention is to overcome the disadvantages of previously known procedures of the foregoing type, and at the same time provide an improved apparatus for atomizing liquids by the use of a perforated member through which the liquid is passed A further object of the invention is to provide an improved apparatus for carbureting fuels for internal conibustion engines.

In accordance with the present invention, the disadvantages and difliculties encountered'in previous efforts to atomize liquids in accordance with the known practice referred to are overcome by providing an apparatus including a perforated member, in which the perforations or apertures receiving the liquid to be atomized are alternately filled with liquid to be atomized and subjected to the action of an atomizing medium. In this operation the only part of the liquid subjected to atomization by the action of the atomizing medium are the liquid droplets present in the perforations or apertures of the perforated member, which droplets are individually blown up and caused to burst, as a result of which a very fine atomization of the liquid droplets in the medium is achieved.

In a preferred construction of the improved apparatus the perforated surface or perforated member is made adjustable with respect to a body of the liquid to be atomized so that the amount of liquid to be atomized, or the rate at which the liquid is atomized can be adjusted in accordance with requirements of the particular operation.

The improved apparatus of the present invention is particularly suitable for use as carburetors for internal combustion engines, as an example. Where this apparatus is used for that purpose, it achieves the finest atomization of the liquid particles of fuel, and in accordance with the invention a carburetor advantageously comprises a stationary tank receiving the liquid fuel to be atomized, an axially displaceable rotatable cylinder surrounding the tank, the cylinder including a band of perforations extending only over a certain area as, for example, a selected area intermediate its ends.

In a preferred construction, the fuel tank is provided with pressed-in pockets terminating in a flat shape toward States Patent 9 the center of the tank, these pockets alternating with tank wall sections provided with slots or openings adapted to register with perforations in the rotatable cylinder. The rotatable cylinder is axially displaceable with respect to the tank in such a way that the overlap of the perforated portion of the cylinder by the tank, or the slotted portion of the tank, and hence the fuel wetted perforated surface of the cylinder is adjustable between zero and the maximum, in order to make the supply of fuel adjust-able according to engine loads.

In the construction and operation of the improved carburetor provision is made for supplying air through the perforations of the rotatable cylinder after they have been wetted with liquid from the fuel oil tank, the air blowing the liquid from the perforations and effecting the atomization, preferably in an extension of the cylinder which communicates with the intake manifold of the engine.

Since only a small proportion of the air for carburetion flows into the intake line or manifold of the engine through the perforated portion of the cylinder, an additional air inlet is provided which is so located that its flow area is adjusted by the axial displacement of the rotatable cylinder. Furthermore in a preferred construction, the outlet portion of the rotatable cylinder is provided with attached guide blades which bring about a tangential inflow of the additional air'into the intake line. These blades also intimately mix the air stream with the fuel-air mixture atomized through the perforated section of the rotatable cylinder.

The invention includes other features, objects and advantages described rnore in detail hereinafter in connection with an illustrative embodiment of the invention described in connection with the accompanying drawings forming a part of this application.

In the drawings:

Fig. 1 is a diagrammatic view illustrating the method of atomization according to the invention and shows the manner in which the atomization occurs at a perforated surface;

Fig. 2 is a diagrammatic vertical sectional view of a carburetor constructed and operable in accordance with the invention; and

Fig. 3 is a cross-sectional view taken on the line 3--3 of Fig. 2.

Fig. l of the drawings shows a metal wall 1, illustrated as being provided with a number of apertures in which droplets of liquid are shown at various progressive stages of the atomization process from left to right. These various stages or apertures are represented by the letters A, B, C, D and E, respectively. In stage or aperture A, the liquid droplet is at rest and represents a condition in which the blowing or atomizing medium, for example, air, is not yet brought into operation. In this stage the adhesion of the liquid is greater than its cohesion in the aperture of the wall, for which reasons the drop of liquid assumes a biconcave shape. When air is blown against the underside of the plate 1 and becomes operative against the liquid droplets in the apertures, the apertures or stages B, C, D and E represent the progressive changes of the liquid droplet as it is blown out from a slightly bowed condition to a wide bow and finally bursts as in stage E, by an active air pressure.

In the final stage E, short flaps of liquid 2 are left at the periphery of the aperture under the action of adhesion. These flaps 2 withdraw into the aperture on interruption of the air supply but the remainder of the liquid droplet is atomized into a fine mist as illustrated. When the wail 1 is again wetted with liquid the process of atomization is repeated, the droplet in each aperture going quickly through the progressive stages shown in Fig. 1, either upon the application of air or gas pressure below the wall 1, or

upon the application of a suction or vacuum above the wall 1.

The apertures provided in the perforated member are of such a size that adhesion of the particular liquid to be atomized is greater than its cohesion, the physical properties of the particular liquid to be atomized being dccisive. The distance between adjacent apertures is influenced by the time required for wetting or filling of the individual apertures or perforations and can readily be determined in any apparatus intended for a particular purpose.

As an example of an apparatus or device constructed according to the invention, and which is particularly adapted for carrying out the improved method, Figs. 2 and 3 show a carburetor of an internal combustion engine arranged to supply the combustion engine fuel to the intake manifold or intake line of the engine. In this view the carburetor is shown as comprised mainly of a generally cylindrical stationaiy fuel tank 3 surrounded by a rotatable axially movable cylinder 4 shown as having a closed upper end 4' and an open lower end. The cylinder 4 is surrounded by a circular-shaped air filter comprising a body of filtering material 5 of suitable known type carried in a filter housing 9.

The stationary tank 3 is supported by an upwardlyaxially extending hollow shaft 6, to which the tank is fixed, the upper end of the shaft being held in fixed position by a sleeve bracket member 7 carried by a bracket 8 attached to the upper surface of the filter housing 9. The tank 3 is cylindrical in form but portions of the outer and bottom walls are pressed in to provide a number of pockets 1t evenly distributed around the periphery of the tank, one of these pockets being shown in Fig. 2 at the left side of the tank and includes a downwardly and inwardly sloping wall 10, the pockets being open at the periphery and bottom. The peripheral vertical edges of adjacent pockets 10 are bridged by a. cylindrical tank wall segment 11, which remains after the pockets 10 are pressed-in. These segments 11 are provided with vertical slots 12 through which the liquid fuel contained in the tank 3 can flow onto the interior surface of the cylinder 4. The upper part of the tank 3 is cylindrical, while the lower part comprises the alternate pockets 10 and segments 11, p the outer surfaces of the segments 11 being in the plane of or constituting a continuation of the upper cylindrical part of the tank 3. The edges or periphery of the slots 12 are properly packed with respect to the interior surface of the cylinder 4 by means of packing strips indicated at 12.

The liquid fuel for the internal combustion engine is supplied to the tank 3 through a fuel line 6 and the hollow shaft 6 by means of passages 14 within the area of the tank, the passages 14 opening into a narrow annular space or compartment 15 in the upper part of the tank. The compartment 15 communicates with the interior of the tank 3 by means of an opening 15, which is closable by a float valve 13. The arrangement of the fuel supply to the tank 3 and float valve 13 is such that there is always a constant quantity of liquid fuel in the tank, thereby immersing the full length of the slots 12. V

The rotatable cylinder 4 is driven by means of a shaft 16 fixed to a gear wheel 17 which meshes with a gear wheel 18, splined to a hollow displacement shaft 19, fixed axially with respect to the upper wall 4 of the cylinder 4 and fitting around the shaft 6. The gear wheel 18 includes an annular groove 18 engaged by a fork 20 fixed to the brace 8 and arranged to retain the gear wheel 18 against displacement. The cylinder 4 together with the hollow shaft 19 is displaceable with respect to the gear 18, the spline or key of the gear being slidable in a longitudinal groove 19' in the shaft 19.

The axial displacement of the cylinder 4 is effected by means of a fork 21 carried by a rod or lever system 22, the fork 21 engaging in an annular groove 21' provided at the upper end of the hollow shaft 19. The cylindrical wall of the cylinder 4 is perforated only in its longitudinal middle section at 23 intermediate its upper and lower solid wall sections 24 and 25, the perforated band or section of the cylinder wall having a width approximating the length of the slots 12 and always being within the scope of the surrounding filter material 5.

When the internal combustion engine, to which the carburetor shown in Fig. 2 is assembled, is not running, the rotatable cylinder 4 is at rest and is located in its lowermost position so that the slots 12 of the tank 3 are covered and sealed off by the upper solid wall section 24 of the cylinder 4. Under these conditions, in the construo tion illustrated in Fig. 2, the lower end of the solid wall section 25 abuts or extends to the upper end of a suction pipe or intake manifold 26 of the engine. If after the engine has been started, its speed of rotation is to be increased, the now rotating cylinder 4 must be displaced axially by means of rod or lever 22 to increase the overlap of the slots 12 of the fuel tank 3 by the perforated Wall section or band 23 of the rotating cylinder 4. When any change in speed of the engine is desired, the rotatable cylinder 4 is adjusted axially with respect to the tank 3 to increase or decrease the amount of fuel being atomized.

As the cylinder 4 rotates during the operation of the engine, the individual apertures of the perforated section 23 communicate at one instant with the body of liquid fuel in the tank 3, during which the apertures are filled with liquid fuel droplets, and at the next instant with pockets 10, during which the liquid fuel droplets are blown into the pockets 10. Because of the reduced pressure prevailing in the intake manifold and in the space 27, produced by the engine, air is aspirated or drawn through the body of filter material 5, the apertures of the perforated section 23, the pockets 10 and into the lower portion of the cylinder 4 and space 27, with the simultaneous atomization of the droplets of liquid fuel present in the apertures of the perforated section 23, in the manner illustrated in Fig. 1 of the drawings.

This atomization of the fuel droplets in the apertures of the section 23 into the pockets 10 and the space 27 produces an over-rich fuel air mixture. However, a passage or section 28 of the lower portion of the air filter 5 is released or made available because of the position of the lower edge of the section 25 of the cylinder 4, by the upward axial displacement of the cylinder 4 while the engine is running, so that additional air can be drawn into the intake pipe 26. It will be seen that the arrangement is of such a nature that when the cylinder 4 is moved downwardly, there will be a decrease in the amount of fuel supplied to the intake manifold because of the shifting of the perforated section 23. At the same time, the lower end of the imperforate section 25 will reduce the area of the opening 28 for the direct supply of air. When the speed of the engine is increased, the reverse operation takes place.

While air in the filter 5 completely surrounds the rotatable cylinder 4, it will be drawn through the per forations in the section 23 only when they are opposite one of the pockets 10 to which suction is applied from the intake manifold 26.

In the area of the lower imperforate section 25, the internal portion of the cylinder 4 is provided with inwardly extending guide plates or fin surfaces 29 so that air flowing in through the passageway 28 is set in r0- tation and an intimate mixture of this air stream with carburetor the guide surfaces 29 may, for'example, be so shaped that the rotation of the rotatable cylinder 24 is elfected by the action of the air being drawn into the intake manifold.

It is also to be understood that an atomizer device, such as that shown in Figs. 2 and 3 may be used for atomizing water or other liquids for various purposes, such as in refrigerating equipment, in which a large contact surface for the medium to be cooled is provided by the atomization effected by the device.

What we claim is:

1. An apparatus for atomizing liquids, comprising a container for holding the liquid to be atomized, a cylinder surrounding the periphery of the container in close relation and being provided with a band of perforations adapted to surround the container, the peripheral wall of the container being provided with liquid distributing means closely adjacent to the cylinder and registering with said band of perforations for supplying liquid to the perforations when the band surrounds the peripheral wall of the container at the position of the distributing means, a gas flow pocket carried by the container open through the periphery of the container to the surrounding cylinder but closed off with respect to the interior of the container, means for effecting relative rotation of the cylinder and container to bring liquid-filled perforations of the cylinder and the gas flow pocket of the container into register with each other, means for effecting relative axial movement of the cylinder and container to vary the extent of overlap between the band of perforations and the liquid distributing means, and means for conducting a gaseous atomizing medium to the perforated band of the cylinder to effect atomization of the liquid in the liquid-filled perforations of the cylinder when they are in register with the gas flow pocket in the container.

2.'An apparatus as claimed in claim 1, in which the peripheral wall of the container is provided with a plurality of liquid distributing means and gas flow pockets, the plurality of liquid distributing means respectively alternating with the plurality of gas flow pockets around the periphery of the container. 7

3. A carburetor for internal combustion engines, comprising a fuel tank for liquid fuel having a cylindrical portion at one end, a rotatable cylinder surrounding the tank in close relation to its cylindrical portion and provided with an annular band of perforations intermediate its ends, means for rotating the cylinder, a portion of the tank within the rotatable cylinder being provided with alternating segments and pockets, the segments having outer surfaces constituting continuations of the cylindrical portion of the tank and being provided respec- Lively with slots for supplying liquid to the perforations of the cylinder, said pockets opening out to the cylinder and through the end portion of the tank opposite said cylindrical portion into the end of the cylinder thereat and providing passages for the flow of air through the perforations of the cylinder, said cylinder and tank being axially displaceable with respect to each other for varying the overlap of the band of perforations with respect to the slots in the segments of the tank, and means for effecting relative axial displacement of the cylinder and tank.

4. A carburetor as claimed in claim 3, including a fuel inlet line for the engine arranged to receive the fuel-air mixture from the end of the cylinder into which the pockets of the tank open, said cylinder including imperforate end portions on the respective sides of the band of perforations, said end of the cylinder being adapted to register with the inlet end of the fuel inlet line when the cylinder is shifted axially to a position where the opposite imperforate end portion of the cylinder covers the slots of the tank and to admit air between the cylinder and inlet line when the cylinder is shifted away from the inlet line in addition to the air passing through the perforations.

5. A carburetor as claimed in claim 4, including guide blades attached to and projecting inwardly from the inner periphery of the portion of the cylinder adjacent the inlet line.

6. A carburetor for internal combustion engines, in which the intake manifold of the engine opens upwardly and the carburetor is mounted thereon, comprising a stationary liquid fuel tank in the form of an upright container mounted in fixed position above the inlet of the intake manifold, a rotatable cylinder axially arranged with respect to the tank and extending therearound in close relation thereto, said tank including a plurality of regularly spaced vertical slots opening to the inner periphery of the cylinder, said cylinder being provided with an annular band of perforations intermediate its ends and adapted to register with the slots of the tank for the supply of liquid from the tank to the perforations in the cylinder, said cylinder including imperforate sections above and below the band of perforations and arranged with respect to the inlet of the intake manifold so that its lower end registers with said inlet when the upper imperforate portion of the cylinder covers the slots in the fuel tank, said tank being provided with exterior pockets respectively alternating with the peripheral slots, said pockets opening out to the cylinder and downwardly toward the intake manifold, thereby providing passages for the flow of air through the perforations of the cylinder to atomize liquid droplets therein, and means for shifting the cylinder axially with respect to the tank for varying the proportion of theband of perforations registering with the slots of the fuel tank.

References Cited in the file of this patent UNITED STATES PATENTS 581,294 Lorillard Apr. 27, 1897 951,923 Van Buren Mar. 15, 1910 1,640,291 Perkins Aug. 23, 1927 2,210,429 Pietzsch Aug. 6, 1940 2,265,500 Stuart Dec. 9, 1941 2,586,692 Morel Feb. 19, 1952 FOREIGN PATENTS 7,767 Great Britain Apr. 2, 1913

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