US2315847A - High vapor pressure fuel vaporizer-carburetor combination - Google Patents

Description

P 0. L. GAR-RETSON HIGH VAPOR PRESSURE FUEL VAPORIZER-CARBURETOR COMBINATION Filed cm. 6, 1941 HIV INVENTOR OWEN L. GARRETSON 4.N V W A Patented Apr. 6, 1943 men VAPOR PRESSURE FUEL VAPORIZER- I CARBURETOR COMBINATION Owen L. Garretson, Detroit, Mich, assignor to Phillips Petroleum Company, a corporation of Delaware Application October 6, 1941, Serial No. 413,838 4 Claims. (Cl. 261-46) This invention relates to carburetors and more retor is one in which liquid gasoline of from ap-- proximately 9 to 12 pounds Reid vapor pressure is used as fuel. Some stationary internal comparticularly it relates to a type of carburetor bustion engines operate on natural or artificial gases, and in some regions trucks, busses and even motor-cars are propelled by internal combustion engines which are fueled by compressed leum gases or mixtures thereof.

An object of this invention is to devise a carburetor for carbureting high vapor pressure fuels.

A further object is the control of fuel flow to the separating means in accordance with the mass of liquid phase therein.

Another oblectis the "provision of gas responsive means for regulating relative feed of liquid and gaseous phases.

These latter engines are equipped with A still further object of this invention is to devise a carbureting device for use with a high vapor pressure fuel, which upon reduction to slightly above atmospheric pressure, i. e., from 1 to 4 pounds per square inch gauge, is separated into a liquid phase and a vapor phase, and carbureting these two phases in the ratio in which they are present in the original fuel.

Still other objects and advantages will be realized by those skilled in the art by a careful study of the following disclosure. a

The figure illustrates one modification of my invention showing my carburetor for use with high vapor pressure fuel.

Referring to the figure, numeral I represents a vaporizing chamber in which the normally gaseous components of the fuel are separated from the normally liquid components. Liquid fuel is conducted from the fuel pressure tank, not shown. through line 2 through pressure regulator 3 and line 4 into vaporizing chamber I. Valve 5 operated by diaphragm 6 and tension spring I controls the flow of fuel from line! into the vaporizing chamber. The vaporizing chamber i is equipped with a heating coil 9 and .thermoregulator l0. Heating fluid enters heating coil through tube II and leaves the coil through tube l2, the flow being controlled by control valve l3. Vapor tube I4 connects vaporizing chamber l with vapor compartment IS, the bottom wall of which is equipped with a zero pressure regulator valve Hi. This latter passes through passage 11, the valve stem being attached to diaphragm 13. Gas feed chamber l9 receives gas through the the passage II. A spring 20 slightly compressed.

when valve I6 is closed and adjusted to open slightly below atmospheric pressure controls the operation of said diaphragm [8, air chamber 2|. being open to the atmosphere through opening 22 or connected to air inlet 33 to balance air cleaner friction. Tube 23 connects vaporizing chamber I to the throttle regulating apparatus 24. The said throttle regulating apparatus is essentially a diaphragm regulator composed of a housing 25, diaphragm 26, tension spring 21 and push pin 28.

Tube 29 connects the liquid containing portion of vaporizing chamber l with the float chamber 30, the flow of liquid fuel being controlled by the float mechanism 3| and valve 53.

The throttle valve portion 32 of the carburetor comprises the air-fuel mixing apparatus. Air enters this apparatus through air inlet tube 33, the stream of air being divided into two portions,

one passing through theliquid carbureting side 34 of the device and the remainder passing through the gas carburetingportion 35. These carbureting parts are equipped with Venturi sections 36 and 31. Liquid carbureting jet 38 connects the liquid containing portion of float chamber 30 with thepoint of essentially maximum vnected to and controlled by diaphragm 26 through push pin 28 pivoted to lever 42 at one end and pivoted to diaphragm 26 at the opposite end.

The push pin 29 has vertical movement in a slot 52. Any suitable means responsive to gas pressure in the vaporizing chamber may be used in place of the diaphragm and push pin arrangement shown to impart relative movement to lever 42. For example, a piston and cylinder arrangement may be utilized connected to lever 42 by suitable means. The said lever is supported by fulcrum pin 44 and manually operated by the manual throttle control 43. Butterfly throttle valve 49 is connected by arm 45 through pivot 41 to the lower side of lever 42 near one end thereof. Similarly, butterfly throttle valve 59 is connected near the opposite end of lever 42 by pivot 43 and arm 46. The liquid carbureting tube or side 34 and the gas carbureting tube or side 35 join into a common tube at the outlet end of the carburetor.

Tube 55 connects the float chamber 39 to the carbureting side of the carburetor on the downstream side of the throttle valve 49 and 50 and carries the control valve 55. A branch tube connects tube 55 with thevapor'space in the float bowl to prevent liquid from draining into the manifold when the engine stops. The float chamber is vented to the air inlet tube by a passage, not shown.

In the operation of my carburetor, hydrocarbon fuel comprising natural gasoline, high vapor pressure natural gasoline containing substantial quantities of normally gaseous hydrocarbons under pressure, flows from the fuel storage tank, not shown, through line 2, pressure regulator 3 and line 4 into the vaporizing chamber i. Pressure regulator 3 reduces the pressure of the incoming fuel from that of the storage tank to approximately from 1 to 4 pounds per square inch. Fuel 7 at this lower pressure enter vaporizing chamber I through valve 5, which valve is operated by diaphragm 9 and tension spring I. The liquid fuel upon entrance into vaporizing chamber evolves as vapor some of the normally gaseous hydrocarbons, and the amount of vapor formed is dependent upon the speciflc hydrocarbons present in the fuel and upon the pressure and temperature maintained within said chamber. I have found that by maintaining a temperature of approximately 120 F. at between 1 to 4 pounds pressure, excellent gas-liquid separation i obtained when using natural gasoline of from 26 to 40 pounds Reid vapor pressure. Provision for warming of the liquid fuel in the vaporizing chamber is made in the form of the hot water coil 9. Hot water from the motor cooling system, notv shown, passes through line ll, into the The diaphragm 6 serves as the bottom of the vaporizing chamber and the top of the vapor compartment l5, and since the gas pressures in these two chambers are essentially equal, the operating force on said diaphragm is the mass of the accumulated liquid fuel as modified by the active tension-in the tension spring I. Thus when the weight of the residual liquid reaches a certain predetermined value, the said diaphragm closes valve 5 which in turn closes off the flow of liquid fuel into the carburetor. The spring 1 is so adjusted that the valve 5 remains closed during the presence of a preponderance of liquid fuel in the vaporizing chamber and until at least a small portion of the residual liquid fuel has passed through tube 29 to float chamber 34, thereby lessening the weight of liquid upon the diaphragm and causing valve 5 to open admitting more fuel to the vaporizing chamber. In ordinary operation due to the normal sensitivity of the diaphragm and adjusting spring, the level of liquid remains essentially constant or varies only within very narrow limits while valve 5 remains partially open depending on the rate of fuel consumption. When the gas pressure in gas feed chamber 9 becomes less than atmospheric as occasioned by the suction of gas from chamber |9 through tube 39 and gas carbureting jet 4| into venturi 31, the diaphragm l8 rises thereby opening the gas metering valve l5 allowing gas to pass through valve opening I'I into gas feed chamber |9 in accordance with the demand. In gas feed tubing 39 is inserted a valve 40 for the restriction or control of gas flow. When valve I5 is open, the gas pressure in chamber l9 and in tube 39 tends to build up due to the presence of the restricting valve 40 and when the pressure becomes greater than atmospheric the diaphragm l8 acts to close valve l6, thereby shutting off the gas flow. In actual operation when the amount'of gas issuing from ga carbureting jet 4| is constant, a pressure equilibrium results which" holds the metering valve I6 open an amount necessary to furnish the proper flow-of gas.

The vapor-free residual liquid fuel from the bottom of the vaporizing chamber I passes through gasoline feed line 29 to the float chamber 30 under the 1 to 4 pounds pressure heretofore mentioned. When this liquid reaches a certain predetermined level in the float chamber,

the float 3| rises and the attached valve 53 closes off the flow of liquid from fuel line 29. A liquid carbureting jet 33 extends from the bottom of thesaid float chamber 30 through the wall of the venturi 35 on the liquid side of the dual carburetor.

The diaphragm throttle regulating device 24 being connected to the top of vaporizing chamber iproportions the amount of residual liquid and separated gas entering the throttle valve portion 32 of the dual carburetor so that these two fractions of fuel may be used in the same ratio in which they are present in the original fuel. This regulating device operates by pressure variations communicated from the vaporizing chamber I through tube 23. When the pressure in chamber increases, diaphragm 26 within housing 25, moves from left to right according to the drawing, and this movement increases the tension on tension spring 21, and is transmitted through push pin 28 to move lever 42 from left to right.

, Slotted lever 42 may move in the above given direction until pivot 41 is directly under fulcrum pin 44, then upon downward movement of the manual throttle control 43, pivot 48 and arm 45 move downward, thereby opening butterfly throttle valve 59. When this gas-side throttle valve is open, air from'inlet 33 passes through the gas side 35 and the corresponding venturi 31 and the vacuum set up at the gas jet 4| communicates backward through tube 39, valve 40 and through tube 39 extended and tends to evacuate the gas feed chamber I! in the lower part of the vaporliquid separator I. This pressure drop cause! diaphragm I8 to open the gase metering valve I which permits the separated gas to-fiow from the vapor containing portion of the vaporizing chamber I into the vapor compartment I5,

- through valve I6 and into vapor feed chamber I9,

thence through tube 39, valve 40, jet 4| and into All during this mains open, that is control 43 is held depressed.

When slotted lever 42 moves from right to left, pivot 41 and arm 45 move upward while pivot 48 and arm 45 likewise move upward, thereby opening butterfly throttle valve 49 and permitting more inlet air to pass through the liquid side 34 ofthe dual carburetor and closing valve 50. As inlet air passes through this section of the carburetor, and thrugh venturi 36, vacuum or suctionis communicated through jet 38 which action draws residual vapor-free liquid fuel through said jet .38 into contact with the flowing air for mixing and passage through the outlet end of the dual carburetor SI and into the intake manifold, not shown. Upon continued consump tion of residual liquid fuel the liquid level in float chamber 30 drops until float 3Icauses valve 53 to open, thereby permitting vapor-free residual liquid to flow from the vaporizing chamber I into the float chamber 39. This liquid continues to flow in this direction as long as float valve 53 remains open. If during this flow the liquid in vaporizing chamber I becomes lowered to a predetermined level or whatamounts to the same thing, the weight of the residual liquid is lessened to a predetermined amount, diaphragm 6 opens the fuel valve 5, thus permitting raw fuel to flow from the pressure storage tank, not shown, through the pressure regulator 3 into the vaporizing chamber I, thereby increasing the weight of-liquid on the said diaphragm and valve 5 closes. Upon the addition of this raw fuel to the vaporizing chamber, vaporization occurs thereby increasing the gas pressure within said chamber. This pressure increase acts through tube 23 on the throttle regulating apparatus 24 to move the push link from left to right to open the gas side butterfly valve 50 for consumption of the vapors evolved in said vaporizing chamber. The gas side of the carburetor functions as long as the gas pressure-in the vaporizing chamber remains within a certain pressure range, say from 1 to 4 pounds per square inch, then when this pressure drops to less than 1 pound the tension spring 21 contracts pulling the diaphragm 26 and connected parts from right to left and feeding more liquid fuel to the carburetor. Thus when the mass of the residual liquid on diaphragm 6 is lessened to a predetermined value, valve 5 ope ns wider permitting more raw fuel to enter the vaporizing chamber at which time the pressure in said chamber increases to open up the gas side of the carburetor as heretofore explained.

When the motor is operating at a constant load and at constant speed, the operation of the carburetor reaches a state of equilibrium in which raw liquid fuel enters the vaporizing chamber I in a small but essentially continuous flow through valve 5, the slight gas pressure increase in said chamber I holds diaphragm 2B in such a position that the push link 42 is held at an intermediate position allowing both throttle valves 49 and 50 to be partiallyopened, thereby permitting consumption of residual gas-free liquid and separated gas in the same proportion in which they occur in the original high vapor pressure fuel. The tension spring 20 is so adjusted that the diaphragm I8 plays its part in maintaining the operating equilibrium under the above mentioned conditions.

3 During periods of acceleration when the manually controlled throttle is opened, the separated gas may be consumed more rapidly in proportion than the residual liquid fuel and the valve 5 is so arranged, as explained heretofore, that the flow of original fuel through line 4 into the vaporizing chamber is controlled solely by the mass of residual gasoline on the diaphragm I5 and not by the pressure of the liberated vapor or gas in v the upper portion ofv the said vaporizing chamber.

The pressure of the liberated gas or vapor in the vaporizing chamber controls the relative position of link 42 so that under certain conditions only separated gas will be carbureted, while under other conditions only residual gas-free liquid fuel will be carbureted, and under still other conditions both the separated gas and the residual liquid are carbureted simultaneously, the overall separate .andindividual carburetion of said gas and said liquid being in the ratio in which these components are present in the original liquid fuel.

For idling of the motor, there may be suflicient air leakage through the butterfly valves to draw sufflcient fuel or definite provision may be made.

In this latter case, tube connects the carbureting portion of the carburetor at a point on the downstream side of the throttle valves 49 and 50 to the float chamber 30 for liquid fuel idling and to the top of the vaporizing chamber I for gaseous fuel idling. In either case an vapor pressure hydrocarbons will be vaporized therefrom. Such an amount of said high vapor pressure hydrocarbons should be removed from the liquid so that there will not be a tendency of the residual liquid to form vapor in tubes and chambers in which there should only be liquid fuel, or in other words the vapor pressure of the liquid fuel should be so reduced that there will be no tendency to form vapor lock. While the temperature of the liquid fuel in this vaporizing chamber may be varied within not too wide limits, some variation is permissible. I have found that under normal operating conditions a vaporizing chamber temperature of F. gives excellent operation when using a natural gasoline of 26 to 40 pounds Reid vapor pressure. When using fuel of higher vapor pressure, the vaporizing chamber temperature may be lower than 120 F. and for lower vapor pressures the tem erature should be somewhat higher. By controlling the pressure and temperature in the vaporizer, I can obtain the volatility characteristic desired in the residual liquid fuel.

alterations of the component parts may be made.

and yet remain within the intended scope of my invention.

I claim.

1. In a carburetion system for internal combustion engines adapted for handling higher than normal vapor pressure fuel, including a vaporization chamber normally containing a body of liquid and a volume of gaseous fuel, a dual branched carburetor, each branch including a Venturi tube and fuel nozzle, a passage for liquid fuel leading from the vaporization chamber connected with one nozzle and a passage for gaseous fuel leading from the vaporization chamber connected with the other nozzle, to induce liquid and gaseous fuel flow in accordance with air flow through said Venturi tubes, the improvement comprising a valve in each branch of the dual carburetor to control the air flow and thereby the relative fuel flow thereto, a fulcrum, a manually operable lever adjustable with respect to said fulcrum, arms pivoted to said lever on opposite sides of the fulcrum and operably connected with said valves and pressure responsive means for shifting the pivots toward and from the fulcrum to vary the position of the valves and thereby the relative proportions of liquid and gaseous fuel induced in the branches by air flow through the Venturi tubes.

2. In a carburetion system for internal combustion engines adapted for handling higher than normal vapor pressure fuel, including a vaporization chamber normally containing a body of liquid and a volume of gaseous fuel, a dual branched carburetor, each branch including a Venturi tube and fuel nozzle, a'passage for liquid fuel leading from the vaporization chamber connected with one nozzle and a passage for gaseous fuel leading from the vaporization chamber connected with the other nozzle, to induce liquid and gaseous fuel flow in accordance with air flow through said Venturi tubes, the improvement comprising a valve in each branch of the dual carburetor to control the air flow and thereby the relative fuel flow thereto, a fulcrum, a manually operable member adjustable with respect to said fulcrum, means pivoted to said member on opposite sides of the fulcrum operably connected with said valves and means for shifting the pivots toward and from the fulcrum to vary the position of the valves and thereby the relative proportions of liquid and gaseous 'fuelinduced in the branches by air flow through the Venturi tubes.

3. In a carburetion system ,for internal combustion engines adapted for handling higherjhan normal vapor pressure fuel, including -a vaporization chamber normally containing a body of liquid and a volume of gaseous fuel, a dual branched carburetor, each branch including a Venturi tube and fuel nozzle, a passage for liquid fuel leading from the vaporization chamber connected with one nozzle and a passage for gaseous fuel leading from the vaporization chamber connected with the other nozzle, to induce liquid and gaseous fuel flow in accordance with air flow through said Venturi tubes, the improvement comprising a valve in each branch of the dual carburetor to control the air flow and thereby the relative fuel flow thereto, a fulcrum, a

manually operable lever adjustable with respect to said fulcrum, arms pivoted to said lever on opposite sides of the fulcrum and operably connected with said valves and means responsive to pressure of the gaseous phase in the vaporization chamber for shifting the pivots toward and from the fulcrum to vary the position of the valves and thereby the relative proportions of liquid and gaseous fuel induced in the branches by air flow through the Venturi tubes.

4. In a throttling arrangement for an internal combustion engine carburetion system adapted for handling higher than normal vapor pressure fuel including means separating said fuel into liquid and gaseous phases, a dual branched carburetor, each branch including a Venturi tube and a fuel nozzle, a passage for liquid fuel leading from the separating means connected with one nozzle and a'passage for gaseous fuel leading from the separating means connected with the other nozzle, to induce liquid and gaseous fuel flow in accordance with air flow through said Venturi tubes, the improvement comprising a valve in each branch of the dual carburetor to control the air flow and thereby the relative fuel flow thereto, a fulcrum, a manually operable lever adjustable with respect to said fulcrum, arms pivoted to said lever on opposite sides of the fulcrum and operably connected with said valves and means for shifting the pivots toward and from the fulcrum to vary the position of the valves and thereby the relative proportions of liquid and gaseous fuel induced in the branches by air flow through the Venturi tubes.

OWEN L. GARRE'ISON.

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