US1553477A - Process of and device for vaporizing liquid fuels - Google Patents

Description

Sept l5, 1925.

J. w. SMITH rnocsss or' Am? vvIcE won vAPonIzms LIQUID FUELS Fil'e'd Noir. 20, 1920 2 Sheets-Sheet 1 Yin INVENTOR: hnl/1651111111,

BY ZL-la7 v- ATTORNEYS.

PROCESS lA AND DEVICE FOR VAPORIZIIG LIQUID FUELS Enea Nov. 2o, 1920 2 shun-shut 2 FIC-: I.

NVENTOR: John/ )fl/ Sm iik,

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Y WITNESSES;

Patented Sept. 15, 1925.

UNITED STATES vPATENT OFFICE.

JOHN W. SMITH, OF EHILADELPHIA, PENNSYLVANIA.

PROCESS 0F AND DEVICE FOR VAPORIZING LIQUID FUELS.

Application iled November 20, 1920. Serial Nol 425,533.

Liquid Fuels, whereof the following is aspeciiication, reference being had to the accompanying drawings.

The invention relates in part to an improved process or method of effecting complete and efficientV vaporiz'ation of commercial liquid fuels, such as the hydrocarbons employed in operating internal combustion engines, and in part to devices by aid of which this process may be economically carried out.

In the production of commercial liquid fuels now on the market, the temperature at the end of the distillation is often above 850 F., so that in order to effect complete vaporization of the fuel for use in an internal conbustion engine, it has been customary, heretofore, to heat a portion ofthe intake manifold to a highA temperature (within a range of from 500o F. to 1000 F.) at a region where the less volatile, higher boiling portion of the fuelwas caused to accumulate. As a result, the whole volume of the mixedair and fuel was raised to such a high temperature as to greatly impair the efiiciency of the engine. Many attempts have been made to obtain a fuel mixtureof low temperature, from 100o F. to 150o F., under the above outlined 'principle of carburation, but this hask been found absolutely impossible. y

The primary object of my invention is to overcome this difficulty. This I accomplish to the best advantage by vaporizing the more volatile or lower boiling portion of the fuel at the lowest possible temperature,

. segregating the unvaporized liquid portion of the fuel, separately vaporizing thislatter portion (apart from the rest) at a very high temperature and returning this less volatile portionin a vaporous condition tov mingle and combine with the aforesaid more volatile portion on its way to the engine cylinders.

Both myimproved process, and the device which I employ in practicing the same will be readily understood from the detailed de'-Y scription .which follows.

In the accompanying drawings, Fig. I is a plan view of al vaporizing device convenient for the purposesof my invention;

F ig. II is a sectional view of the device in association with a carbureter and'with the exhaust manifold of anV internal coinbustion engine.

Figs. III and IV are plan sectional views,-

the horizontal planes of which are indicated respectively by the arrows `III-III and IV-IV in Fig. II.4 l

Myimproved device is applicable as an auxiliary to any standard vtype of carbureter, so that no showing of a carbureter is here required save the outlet indicated at 1 in Fig. II.- This outlet is governed or f controlled in the usual manner by a throttle valve 2 under the actuation of a control lever 3. Superposed as an axial continuation of the carbureter 1 is a vertical, cylindrical element 5. The bore of this element 5 is somewhat larger in cross Asection than the carbureter outlet, and is approached through a divergent Hare shown at 6. In passing through the element 5, the air and liquid fuel mixture from the carbureter is permitted to expand somewhat, and caused to swirl by a stationary spiral deflector element 7. The turbulence or agitation thus produced serves to facilitate vaporization of the more volatile portion of the fuel and separation of theunvagorized portion as will hereinafter be more fully explained.

The element 5 is, in turn, surmounted by a fitting 8 formed with a neck 9 aligned as an axial continuation of the element 5. These parts 5 and 9 form a portion of the main intake conduit of the engine. The top of the neck 9 is appropriately faced, `and provided with bolt holes 10 for the attach-- ment of the intake manifold of the gas engine, indicated at 11 in Fig. II. The fitlting 8 has a shallow, hollow, rect-angular pass which comprises the inlet and outlet branches 15V and 16. In the `inlet branch 15 of the by-pass are short spaced vertical partitions 17 and 18, whose forward ends are tapered and curved, as best shown in Fig: IV and an inwardly extending proj ection 19 serve a purpose which will be later explained. n the bottom of the inlet pass as here shown at about the region of the y partitions 17, 1S) is a transverse dani, in

the forno of a downward offset of the floor, over which the fuel traversing said pass falls or cascades.v ln the branch 16 is likewise a single, central, vertical partition 20 of somewhat greater linear extent than the partitions of the branch 15. flat their source, these branches merge respectively with semi annular channels 21, 22 extending part way about the main conduit and separated by a nozzle sleeve threaded axially into an opening in that port-ion of the diaphragm 13 which'extends across thc conduit As clearly shown in Figs. l, lll and 1V, the fit-ting 8 is formed at one side with an eccentric bulge indicated at 24 in Figs. l and Il with the result that the sectional configuration of the channel 21 (Fig. IV) assumes the form of the segment of a gradually expanding spiral. The channel 22 is of the saine. width as the branch 16 of the by pass, and its curved wall 25 is eccentrically disposed with respect to the sleeve nozzle 23, so as to gradually contract the passage toward the front, see Fig. IH. The flattened portion 26 of the wall 25 serves as a reacting surface for deflecting the vapor from the channel 22 into the main conduit, as hereinaf'ter described. i

The lower periphery of the nozzle sleeve 225 has a lip which overhangs the top and a. narrow zone of the inside surface of the element 5 with very slight clearance, thusI affording a comparatively narrow, annular, trap orifice 27. Referring still to Fig. Il, it will be noted that t-he top edge of the element 5 projects above the floor of the channel 21, so as to retain the unvaporized fuel drawn into the Toy-pass during the operation of the. device. The lower portion yof the nozzle sleeve 23 is flared as at 29, while its reduced upper end extends well into the bore ot the neck. 9 of the. fitting 8. .From the illustration, it will be noted that the annular space 30 around the reduced upper portion of the nozzle sleeve 23 is considerably larger in area than the orifice 27. las a consequence, a difference of pressure is maintained between these points under the suction of the cylinders of the engine as the main charge is drawn upwardly through the lgradually contracted area of the nozzle bore. The difference of pressure thus established tends to produce rapid flow through the by'- pass. may be controlled and regulated by a butterfly valve 31, ypreferably coupled, so as to be simultaneously operable with v'the throttle 2 of the carburetor, by means of a link 32. It is to be particularly noted that the size of ther valve disk 31 as compared It desired, this pressure differencev with the area of the opening through the nozzle sleeve 28 is such as to have very limited throttling effect for most speeds of the engine, and none at all for high speeds. lt is also to be noted that the opening through the nozzle sleeve 23 is. o an ar i equal to that of the icarl'iureter outlet 1, and hence capable ont permitting the passage ot the maxi-mum capacity of the carburetor.

ln order to effect vaporization cgt the liquid fuel drawn into the bv-pass of the e2;- tension 12, the latter is almost wholly disposed within an enlarged portion Sie of the exhaust manifold 34 of the engine (shown only in Fig. ll). rllhe enveloped port o the extension is appropriately finned as at 35 to provide an extensive heating snr ace. whereby the rapidity oitthe evapor i is enhanced. in integral head external flange 36 on the tting 8 serves as a cover .tor the opening in the manifold through which the finned end ont the extension 12 1s passed in assembling, and these elements are securedto each other by means ot clamp bolts shown at 37.

T he voperation of the device is as toll The charge liberated by the carbureter drawn upwardly through the outlet into the bore of the element 5 of' the intake conduit, under the suction orn the engine cylinders. The turbulence or agitation set up in the mixture during its passage through the element 5 not only tends to cause evaporation of the more volatile, lower boiling portion of the fuel, but also 'causes the unvaporized liquid fuel of higher boiling point to be separated from the more volatile portion, and collect on the walls of said element. Ordinarily, I prefer'to increase this turbulence or agitation by aid of the spiral 7.. which not only facilitates the evaporation ot the more volatile portion ot the fuel, but

also causes the unvaporized accumulation to be directed upwardly toward the annular trap orice`27, whence it vfinds its way into the channel 21. lhile the spiral' detiector element 7 serves to enhance the turbulence or agitation in theintake conduit andV the efiiciency ot the device,'it is not absolutely essential, and may, if desired, be omitted. lminediately upon entering the channel 21, the liquid flows along` the floor of the branch 1.5 of the by-pass of the extension 12. Any tendency of the liquid to gyrate under the influence of the charge passing through the structure is offset by the curved forwardv ends ofthe vertical partitions 17 and 18 and by the projection 19 of the branch 15 which catch the liquid globules released at a tangent, and thus tend to divert or deflect them and at the same time, to distribute the same, as suggestedhy the arrows in lV. The liquid then flows over thc dani 28. As

soon as it encounters the heated portion of"V ill) the extension i2 within-the manifold 34, the liquid fuel is quickly vaporized, somewhat after the mannerof a flash boiler'. The vapor passes about the outer end of the diaphragm 13 and through the branch 16, and is drawn into the channel 22, whence it finally escapes through the larger annular opening 30 and re-enters the main conduit of the structure to commingle with the main charge.

Under the vacuum that obtains in the engine intake 5 beyond the throttle 2, the more volatile or low boiling portion of the liquid fuel is vaporized at av minimum temperature,-materially lower than at the substantially higher pressure (approaching atmospheric) that exists below the throttle. Again, only a smalll part (by weight) of the air and fuel mixture entering the intake passes through the heating element and this remains in the heating element only until the temperature of Vaporization (under vacuum) is reached being drawn out before any appreciable rise above this point can take place, so that the temperature of the gas entering the engine as a whole is very little affected by the commingling of the high temperature vapor with the main part of the charge. VOwing to the relatively low temperatures at which both portions (more or less volatile) of the liquid Ifuel are vaporized and to the small proportion vaporized at the higher temperature, the average temperature of the gas entering the engine is surprisingly low. Also, thistemperature is remarkably constant. Thus, I have been able to obtain an eiicient dry gas which in practice has been observed to vary only between 100o and 120o Fahrenheit under all conditions of motor performance, notwithstanding temperature variations between 500 and 1000 degrees in the heating element and atmospheric temperature changes of 50 degrees or more.

Having thus described my invention, I claim:

l. The process of producing, from liquid fuel, combustible vapor for internal combustion engines which consists in expanding and agitating the atomized fuel to facilitate vaporization of its more volatile constituent and isolation of the unvaporized portion, vaporizing the more volatile portion under vacnum at the lowest possible temperature, diverting the segregated less volatile portion, separately vaporizing the same under a different vacuum pressure at a very high temperature, and thereafter combining the vaporized more-and-less volatile portions without appreciable rise in `temperature of the resultant mixture.

rlhe process of producing, from liquid fuel, combustible vapor for internal combustion engines which consists in expanding 'and agitating the atomized fuel to facilitate vaporization of its more volatile constituent prises agitation of the mingled air and fuel from the carb'u'reter under the vacuum of the engine intake to vaporize the more volatile constituent and segregate the unvaporized portion; separately vaporizing the latter portion by flash action under the intake vacuuml with a difference of pressure at a' very high temperature; and thereafter combining the portions vaporized without appreciable rise in temperature of the resultant mixture- 4. A device of the character describedy comprising an internal combustion engine intake conduit wherethrough an air and liquid fuel mixture is drawn; and a heating bypass, for vaporizing unvolatilized liquid fuel of said mixture apart from the rest thereof` communicating with said conduit at its inlet end through a relatively small opening and at its outlet end through a larger opening, so as to return the'fuel therein vaporized straightway to said conduit and avoid overheating thereof. i

5.v A device of the character described comprising an internal combustion engine intake conduit wherethrough an air and liquid fuel mixture is drawn; a heating baffled by-pass, for vaporizing unvolatilized liquid fuel of said mixture by flash-action apart from the rest thereof, communicating with said conduit at its inlet end through a relatively small opening and at its outlet end through a larger opening; said conduit having its area reduced between the ends of said ley-pass to cause a difference in pressure for producing flow through' the latter.

G. A device Vof the character described comprising an internal combustion engine intake conduit wheret-hrough an air and liquid fuel mixture is drawn; a heating bypass for vaporizing unvolatilized liquid fuel of said mixture apart from the rest thereof, communicating with said conduit at its inlet end through a narrow annular opening, and at its outlet end through an annular opening of relatively larger area; and a nozzle sleeve in said conduit separating the aforesaid openings and serving to-maintain a difference in pressure between them for producing flow through the by-pass.

7. A device of the character described comprising an internal combustion engine intake conduit Wherethrough an air and liquid fuel mixture is drawn; a heating bypass for vaporizing unvolatilized liquid fuel of said mixture apart from the rest thereof, communicating with said conduit at its inlet end through a narrow annular opening, and at its outlet end through an annular opening of relatively larger area; a nozzle sleeve; anda valve for controlling and regulating the flow through said nozzle sleeve.

8. A device of the character described comprising an internal combustion engine intake conduit wherethrough an air and liqid fuel mixture is drawn; a vaporizer casing projecting laterally from and communicating with said conduit internally subdivided to afford a heating by-pass for vaporizing unvolatilized liquid fuel ofsaid mixture apart from the rest thereof; and means for diverting and passing` such unvolatilized liquid fuel from said conduit through said by-pass. Y v

9. A device of the character described comprising an internal combustion engine intake conduit wheretlirough an air and liquid fuel mixture is drawn; and a flash-action baflied vaporizer projecting laterally from and communicating by a narrow orifice with said conduit, said vaporizer having vertical partitions whose forward ends are tapered and curved, and an external casing for attachment to an exhaust manifold.

l0. In a device of the character described, means affording a main air stream isolated from the vaporizer path as to surrounding walls and mixture communication during the period of vapoi'ization, said vaporizer path having a constricted inlet from the mainstream and a relatively7 larger outlet for returning the vapor to the main air stream, and said inlet and outlet being effective to produce a difference of pressure in the vaporizer whereby constant circulation therethrough obtains.

In testimony whereof, l have hereunto signed my name at Philadelphia, yPennsylvania, this 17 th day of November, 1920.

JOHN W. SMTH.k

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