US2323525A - Feeding of fuel to engines - Google Patents

Description

July 6, 1943. w K, EBEL ETAL 2,323,525

` EEEDING 0E FUEL To ENGINES Original Filed'April 29, 1938 2 Sheets-Sheet 1 SMM/MA July 6, 1943. w. K. EBEL. ETAL FEEDING` oF FUEL To ENGINES originell Filed April 29, lesa 2 Sheets-Sheet 2 52 tgv Patented .IuIy 6, 1943 FEEDING 0F FUEL T0 ENGINES William K. Ebel, Kingsville, and Arch E. Houstle, Jr., Baltimore, Md., Nathan F. Scudder. Los Angeles, Calif., and William B. ONeal, Balti- Company 2 Claims.

The present invention relates to the feeding of fuel to engines, and particularly to the feeding of gasoline to internal combustion engines in aircraft.

This application is a division of application S. N. 205,032, led April 29, 1938.

In the past, diiiiculties have been experienced with all types of engines in the feeding of fuel thereto, in that at times the feed of fuel has been blocked so that no fuel is supplied to the engine. This has been particularly true in the case of aircraft engines, especially during rapid climbing of the aircraft. It has been noted that this difficulty is more pronounced during hot weather and when the fuel is hot. Various efforts have been made to avoid this trouble by the use of fuel cooling devices, special pumps, and fuel lines of large diameter.

The theory of these prior devices is that they will diminish the tendency of the fuel to vaporize in the fuel lines, supposedly causing what is known as vapor locking. The idea has been that since the fuel contains considerable amounts of 10W boiling hydrocarbons, the reduction in barometric pressure during a rapid climb coupled with the agitation of the fuel and the heat to which it is subjected will cause vaporization of the lighter fractions, thus filling the fuel lines with vapor and preventing the flow of fuel therethrough. The prior art arrangements based on such assumption have reduced the difficulties to some extent, but have not been entirely satisfactory.

Applicants have found that this type of trouble also arises under very low temperature conditions, even though the best of the prior art arrangements for eliminating the difficulty are used. Even at temperatures at which vaporization of the hydrocarbons would be impossible, if caused by temperature alone, during climbing some sort of gas does escape from the fuel in sufilcient amounts to stop the operation of the carresides in the fact that according thereto no eff fort is made to prevent the formation of vapor in the fuel feed lines, but instead an accumulation of gaseous material is permitted to form in the line at a suitable point, and is there separated from the liquid fuel and removed from the more, Md., assignors to The Glenn L. Martin l \Oriinal application April 29, 1938, Serial No.

205,032. Divided and this application February 10, 1941, Serial No. 378,304

(Cl. 18S-2.5)

line. Thus the provision of special types cf pumps, fuel lirios, or the like is unncccessary, and instead it is possible by utilizing a very simple and inexpensive device to avoid the disadvan vapor which upset the operation of the carburetor. The fuel supply to the carburetor is not actually blocked, but the presence of the bubbles creates unsatisfactory operation sufficient at times to stop the engine.

The device is provided wth a vent line which is intended to return the vapor separated from the liquid fuel to the source of fuel supply, so that any useful constituents of such vapor may have an opportunity to condense and will not be wasted.

It is obvious that with such return means, particularly where a pump is used for feeding fuel to the engine. it would be very possible that liquid fuel might be pumped back through the same line. An additional object of the invention, therefore. contemplates thel provision of means for preventing the return of liquid fuel through the vapor return line.

In the preferred form rf the` invention, the Separating device is utilized at a point just before the fuel enfers the carburetor. Thus the gases are separated at the proper time. at which there will be practically no opportunity for further separation or for the absorption of further gases in the form of bubbles within the separator and the carburetor.

Further objects and adrantagrs of the invention will appear more fully from the followingi description of the invention, particularly when taken in conjunction with the accompanying drawings, which form a part thereof.

In the drawings:

Fig. 1 is a diagrammatic showing of a feed system for engines including our novel vapor separator.

Fig. 2 is a vertical cross section through the device;

Fig, 3 is a section on the line 3-3 of Fig. 2;

Fig. 4 is a vertical section through still another form of the device.

Fig. 1 shows the arrangement of the separator A in a fuel system. Fuel from a tank 24 is drawn through pipe 26 by a pump 28 and fed therefrom through pipe 30 to the inlet 2 of the separator A. From the outlet 4 of the separator a pipe 32 runs to the carburetor 34, from which the mixture formed in the carburetor is fed through a pipe 36 to the engine 38. The gas outlet pipe I6 extends to the top of the tank 24.

A form of the separator device is shown in Figs. 2 and 3. 2 is the fuel inlet to, and 4 the fuel outlet from, a chamber IDI. This chamber is separated horizontally at a point above the inlet 2 by a wall 40 provided with apertures 42. The fuel inlet 2 enters tangentially into the chamber, so that the fuel forced into the chamber partakes of a swirling movement in which the gases held in the gasoline have an opportunity to escape. These gases rise through the apertures 42 and escape through the passage I4 and gas outlet pipe I6, being returned to the fuel tank.

In the center of the plate 4U is provided a well 44. The tangential injection of the fuel into chamber I' produces a swirling action. The weil portion 44 assists in establishing the swirling action and prevents the direct flow of fuel from the inlet to the outlet. It will be noted that tangential inlet and outlet 4 are mounted on the periphery of chamber I0 in spaced relationship. Upon a condition of low velocity flow, amounting to a trickle, fluid will merely flow into chamber Iii through the inlet and be discharged from the outlet without any particular positive motion of the fluid within the chamber. It is likely that the fluid from the inlet will take the most direct route to the outlet and no gas separation will take place. As the velocity of the fluid increases in the inlet, the motion of the fluid within the chamber becomes more turbulent and applicants have found that the depending well portion extending into the chamber, substantially as shown so that it extends into the path of the incoming fluid, assists in establishing the vortical motion of the fluid. A positive circular path is formed by the walls of the depending well portion cooperating with the walls of the chamber I0' to cause the fluid adjacent the inlet to start on a circular path that will eventually cause the vortex in the chamber as the velocity of the inlet fluid increases.

The depending well portion does not give any motion to the fluid but it does aid in defining a curved path which transforms the linear motion of the uid at the inlet into eventual vortical i motion in the chamber.

The operation is as follows:

When the pump forces fuel through pipe into the separator A, such fuel swirls around the inside of chamber I0. Within the chamber III, any gases which are dissolved or held in the fuel will separate therefrom and will rise to the top of the chamber, whence under the pressure furnished by the pump they will be forced back through the pipe I6 to the tank 24. Some of such gases will probably then condense in the tank 24, but even such as do not are removed from the fuel supply to the engine. The device thus eliminates from the gasoline which is being fed to the engine the gases and vapors which would otherwise be likely to cause vapor locking."

The device shown in Fig. 4 is similar to that of Fig. 3, but is also provided with means for preventing the flow of liquid through the gas outlet pipe I6. Above the plate 40 is provided a second member 45 having mounted thereon an upwardly extending tube 46 provided with apertures 48, so that gas rising through holes 42 may pass up and escape through the openings 48. Concentrically mounted on the tube 48 is a float 50, which supports on its top a ball 52 opposite a conical seat 54 at the entrance to the gas outlet I6. The ends of the strap are secured to the float and the strap is wide enough to rest on top of the perforated tube and supports the ball 52. The sectioned member surrounding the ball with the countersunk opening also rests on the strap and forms a centering device to prevent the ball from rolling off the strap. Obviously, if the liquid fuel should rise in the chamber Ill, it will eventually raise the float 50 and force the ball 52 against the seat 54, thus closing off the gas outlet tube I6.

It should be evident from the foregoing that the invention is not necessarily applied to a p0rtion of the line between the fuel tank and the carburetor, but that any means may be used in which the escape of the gases is effectively permitted.

While we have described herein some embodiments of our invention, we wish it to be understood that we do not intend to limit ourselves thereby except within the scope of the appended claims.

We claim:

l. In a fuel feed system, a gas escape device comprising a chamber, a horizontal partition dividing said chamber into upper and lower compartments, tangentially arranged fuel inlet and outlet conduits arranged in said lower compartment, an integral centrally positioned depending well portion having a closed bottom in said partition extending into the lower compartment of the chamber, a plurality of openings in said partition disposed around said depending well portion and a gas outlet leading from the top of the upper compartment of said chamber.

2. A deaerating device for liquid comprising, a vertical cylindrical chamber, a horizontal partition dividing said chamber into upper and lower compartments, a tangential inlet for fluid to said lower compartment whereby the fluid is caused to assume vortical motion in said compartment, a tangential outlet extending from said lower compartment, in the direction of the motion of the fluid at the point of tangency, said partition having a centrally located well portion having a closed bottom extending into said lower chamber, a plurality of apertures formed in said partition around said well portion, and a gas outlet from the top of said upper compartment.

WILLIAM K. EBEL. ARCH E. HOUS'I'LE, JR. NATHAN F. SCUDDER. WILLIAM B. ONEAL.

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