US2708922A - Means for starting internal combustion engines - Google Patents

Description

G. L. NEELY May 24, 1955 MEANS FOR STARTING INTERNAL COMBUSTION ENGINES Filed July 12, 1952 mvrsmon (iearge L. Neey ATTORNEYS United States Patent Office 2,798,922 Patented May 24, 1955 MEANS FOR STARTING INTERNAL COMBUSTION ENGINES George L. Neely, Berkeley, Calif., assignor, by mesne assignments, to California Research Corporation, San Francisco, Calif, a corporation of Delaware Application July 12, 1952, Serial No. 298,629

7 Claims. (Cl. 123-1875) This invention relates to the starting of internal combustion engines and particularly to means for initiating the starting of such engines when they are cold.

It is common knowledge that the starting of internal combustion engines becomes more difficult to accomplish as the temperature of the engine and the surrounding atmosphere becomes lower and that eventually a temperature is reached at which the engine will refuse to start unless auxiliary starting aids are employed.

The minimum starting temperature will vary among engines and depends, among other things, on the design of the engine, its mechanical condition, and the fuel used. Some diesel engines prove difficult to start at what may be considered normal atmospheric temperatures, and substantially all diesel engines are difficult to start on normal fuels when the ambient temperatures approach F. Although this invention is directed primarily to starting internal combustion enegines of all types when the atmospheric temperature is about 0 F. and lower, it has been found beneficial in starting engines which are difiicult to start when the atmospheric temperature is much higher.

It has been proposed heretofore to start a cold engine 1 with a priming fuel which also would be used to keep it running until the engine warmed up to such a temperature that it would operate on its ordinary fuel. Such priming fuels as those disclosed in the U. S. Letters Patent 2,431,322 to R. Wayne Goodale, issued November 25, 1947, have proven beneficial in starting cold diesel engines. Such a fuel may comprise, for example, the following ingredients: approximately 90% by volume of an ether such as diethyl ether; approximately 10% by vol- The vapors from they reach a certain concentration in air. Because of the volatility of the fluid, such a concentration may readily and rapidly be accomplished accidentally when such is not desired, especially if the fluid is handled in an open and improperly sealed container or is poured from a container into auxiliary apparatus on an engine. This is especially so if the operation takes place in a closed or confined space.

It is desirable in starting a cold engine that only a sufficient amount of such a priming fluid be used as will start the engine and keep it running until conditions are reached where the engine will take hold and operate on its normal fuel. The priming fuel is designed to start and operate a cold engine, and if its use is continued after the engine becomes warm, the properties of the priming fuel are such that it may cause detonation in the combustion chambers to such a degree that the engine may be mechanically damaged. Furthermore, from the standpoint of safety, it is not desirable to have any excess amounts of the'priming fuel left over after the engine has been started because of the hazards which can be incurred by spillage or evaporation-thereof. Because of the efiicacy of the priming fuel disclosed by the present invention it is possible to contain in a very compact volume an amount thereof sufiicient to start a cold engine and to confine this volume of fuel in a package which is safe and convenient to store and handle.

This invention presents a novel priming fuel and a means for containing the fuel in a receptacle, hereinafter called a bulb, from which it can be injected into an engine in a manner which enables the fuel to be employed efficiently and causes the engine to start readily at low temperatures with a minimum quantity of starting fuel required. The number of bulbs of priming fuel required to start an engine will vary in accordance with the size of the engine, the starting temperature, and other variables. For a small engine will sufiice to have one discharger mounted on it by which a series of single bulbs can be discharged sequentially into the engine to provide sufficient priming fuel for starting and initial running. In larger engines it may be desirable to provide a plurality of dischargers to enable several bulbs to be discharged simultaneously or in rapid sequence to provide the desirable amount of fuel.

An object of this invention is to provide a priming fuel for starting cold engines, the priming fuel comprising a combination of normally liquid and normally gaseous or vaporous combustible agents, which agents are conditioned to act together to provide improved starting characteristics for the fuel.

Another object of this invention is to provide a container having its total volume substantially filled with agents beneficial in starting cold engines, the agents being conditioned to be expelled from the container under such pressure and in such a form that they will be carried into the engine in a readily volatilizable spray to form an explosive mixture in the combustion chambers.

A further object of this invention is to provide a fuel which will have an increased elfectiveness for starting cold engines, and to provide a device by which such fuel can be handled and used safely.

Another object of this invention is to provide a measured quantity of a starting fuel hermetically sealed under pressure in a durable container and conditioned to be released therefrom at the will of the operator in the form of a fine spray.

Other objects will be obvious or will become apparent as the description of the invention proceeds.

In order to exemplify one embodiment of the concept of this invention, it shall be described as applied to a starting fuel containing diethyl ether. It has been known to the art for some time past that this ether can be used as a priming fuel to start internal combustion engines under conditions where the fuel used normally to operate the engine is not effective for starting purposes. Particularly is this so when the temperature of the engine and the atmosphere surrounding it are below the point at which the normal fuel will volatilize enough to produce sufficient vapors to form a combustible mixture with air in the combustion chambers, or, in the case of diesel engines, below the point at which the temperature of the mixture in the combustion chambers can be raised a sufiicient amount by the compressive action of the pistons to produce auto-ignition. The high volatility of the ethyl ether and its ready flammability over a wide range of air mixtures lend themselves admirably to the use of this substance as a priming fuel for starting engines under conditions where the normal fuel is ineffective. However, temperatures are reached under normal winter conditions in some parts of the earth where diethyl ether itself ordinarily is not effective for cold starting of some types of engines.

It has now been found that a priming fuel more effective than ether can be produced by combining the ether with a flammable gas under pressure in a device from which the fuel combination can be released in the form of a fine spray in a condition to be more readily volatilized and combined with air to form an explosive mixture. The flammable gas is itself a fuel component which enhances the combustibility of the mixture and is chosen to be compatible with, and to combine with, the ether to produce the enhanced characteristics which result in the improved priming fuel.

Since the priming fuel employed in this invention comprises flammable gases and highly volatile liquids, some of which, as in the case of diethyl ether, may release noxious fumes, a measured charge of the fuel is placed in an appropriate container wherein it can be sealed under pressure in a manner to prevent leakage therefrom. One such container suitable for this purpose is a drawn steel bulb of the general type commonly employed to package charges of CO2 gas under pressure. As is well known, such a bulb comprises a generally cylindrical body portion closed in a unitary manner at one end and necked down at the other end to form an opening of reduced size. When the bulb is filled with its contents, the opening is sealed by a pcrforable closure in a manner to prevent leakage therefrom. The invention is exemplified by reference to the accompanying drawing wherein Figure 1 is a side elevation schematically showing the manner of use of the invention; and

Figure 2 is a sectional view along line 22 of Figure l.

The bulb of priming fuel is discharged by puncturing the perforable closure 11 thereof. to provide an opening through which the contents are released. The puncturing medium may be a hollow needle 12, in which case the opening through the needle provides a conduit for the escape of the contents of the capsule. Preferably, the capsule is placed in a puncturing device 13 which will confine the discharged products and entrain them in tubing 14 or the like, through which they will be conducted to an appropriate part of the engine 15, such as the intake manifold. A suitable discharging apparatus for this purpose is exemplified in U. S. Patent 2,601,211, issued June 17, 1952, to George L. Neely. It is intended that the entire contents of the bulb will be discharged into the engine when the bulb is punctured, and there will be no residue of ether or other combustible substances remaining in the bulb to create hazardous conditions.

As one embodiment of this invention, a steel bulb having a capacity of approximately 10 cc. has placed in it approximately 7.5 cc of diethyl ether. The open bulb then has introduced into it a flammable gas or vapor under pressure, and the bulb is sealed. The gaseous medium is chosen to be one which will be readily ignitable at low temperatures, so that substantially the total contents of the bulb will be made up of substances which will enhance the cold starting function of the priming fuel. Also, the gaseous medium is chosen to be one which will combine with the ether to prdduce a finely divided spray when the bulb is pierced and its contents released. The priming fuel therefore will encompass both the liquid and gaseous mediums.

It has been found that if the normally gaseous medium is one which is soluble to some degree in the ether under the conditions of pressure which exist in the sealed bulb, a desirable spray form is achieved when the contents of the bulb are released. One gaseous agent which has been found beneficial for use in this invention is methane. This gas is soluble in ethyl ether in an amount of ap proximately 0.05 moles of methane per liter of ether per atmosphere of pressure at 70 F. Methane is a cornbustible substance, and has a range of flammability at about 70 F. and 1 atmosphere pressure from about 5% to 15% on a percentage by volume basis when mixed with air. Natural gas, which is essentially methane, may

be used as the gaseous fuel component of this invention.

An open steel bulb of the capacity described heretofore containing 7.5 cc of other is exposed to methane or natural gas at about 600 lbs. per sq. in. pressure for two seconds, and, while still under pressure is sealed. The amount of pressure placed on the gaseous medium while filling the bulb and the time of exposure of the contents of the bulb before sealing it may be varied. However, it is desirable to inject sufficient gas into the bulb so that after it combines in part with the ether there will still remain sufficient pressure at low temperatures, which may be- F. or lower, to expel the contents of the bulb into the engine system.

Another embodiment of this invention comprises a priming fuel in which the liquid constituent is made up of the following components:

Diethyl ether percent by volume 60-95 Methyl alcohol do 1-5 Propylene oxide polymer do 5-30 Ether anti-oxidant percent by weight 0.05 to 0.5

Dye sufficient for desired strength of color.

The propylene oxide polymer component of the above combination contributes several beneficial effects to the fuel. One of these effects results from the high solubility of the ether in the polymer. When this priming fuel is sprayed into an engine, a portion of the ether will be carried in solution in the polymer with which it will be deposited on the walls of the chambers and conduits through which the fuel passes. The ether will be released from solution over an appreciable period of time to make ether vapors continuously available to enrich the fuel mixture in the combustion chamber after initial firing is achieved but while the engine is still warming up to an operating temperature sufiiciently high to use normal fuels efficiently. Another purpose of the propylene oxide polymer is to provide upper cylinder lubrication for the engine during initial starting, before the lubricating system of the engine is effective to provide adequate lubrication in this region. In the case of diesel engines especially, the polymer not only lubricates the metal frictional surfaces from which the normal lubricant has drained prior to starting, but it also provides a liquid sealing medium between the piston rings and cylinder walls to reduce blow-by on the initial strokes of the pistons and hence makes available the full compressive effect of the pistons for creating suitable temperatures in the combustion chambers for compression-ignition starting. Although the use of a mineral oil has been suggested in the past to achieve some of these purposes, such materials have proven not to be suitable, and in fact deleterious to use in priming fuel injection systems which have rubber or rubber-like seals and elements in the apparatus, because the rubber will be attacked by the lubricant and render the discharging device useless.

The methyl alcohol component of the fuel com-bination is provided to be available to combine with any water or water vapors that may be present in the system to prevent the formation of ice crystal in the cofined passages of the apparatus at the depressed temperatures associated with cold starting. Obviously the priming fuel can be effective for starting a cold engine only if it reaches the combustion chambers thereof in the proper form, at the proper time, in sufiicient amounts, and icing in the system will materially affect its operation. It may be noted that both the methyl alcohol and the propylene oxide polymer mentioned above will be combustible in the engine under ordinary running conditions.

The ether anti-oxidant component is added to the fuel combination to prevent the formation of peroxides in the other base fuel during storage thereof.

The dye is added for inspection purposes.

The preferred composition of the liquid constituent de scribed immediately heretofore is as follows:

gallon of fluid.

For purposes of comparing the efiicacy of priming fuels made in accordance with this invention with a priming fuel of diethyl ether pressurized with an inert .gas, similar steel bulbs have been filled as follows:

Bulb Liquid Gas A Ethern; Methane. B Ether base fuel described above Methane. C Ether '00:. D Ether base fuel described above CO2.

Each bulb contained 7.5 cc. of the designated liquid fuel component and each was exposed'to the designated gas fortwo seconds at 600 pounds pressure and sealed under pressure in the same manner, as described heretofore.

Comparative tests were run in engines to evaluate the starting abilities of the various bulbs. One engine used for testpurposes was a six cylinder, four stroke cycle Caterpillar diesel engine with a 4 inch bore and 5 /2 inch stroke rated at 65 H. P. at 1200 R. P. M.

The engine was placed in a cold room and the temperature dropped to approximately 30 F.,- sufiicient time being provided so that the engine and its components, as well as the surrounding atmosphere were at substantially equilibrium temperatures, both initially and prior to each attempted starting of the engine, in accordance with the usual practice for this type of testing. A discharging device of the type shown in the aforesaid Patent 2,601,211 was connected to the engine so that the priming fuel would be discharged into the air intake manifold.

With the cold room at approximately -30 F., seven type A bulbs, i. e., the ethyl ether-methane combination priming fuel, discharged sequentially into the air intake manifold of the engine, started it in seconds cranking time at 188 R. P. M. cranking speed. However, when seven bulbs containing ether pressurized with CO2 gas, i. e., type C bulbs, were discharged sequentially through the same discharger on the same engine at a cranking speed of 175 R. P. M., the engine did not start, and it was necessary to continue cranking the engine for sixty seconds while a total of eleven bulbs were discharged be fore the engine could be started.

Further tests were made in another, but similar engine to that described above, also at approximately F. where six type B bulbs started the engine in 24 seconds at a cranking speed of 119 R. P. M. whereas eleven type D bulbs failed to start the engine after a cranking time of seconds at 128 R. P. M.

The cold room was next dropped in temperature to 40 F. and an attempt was made to start the first described engine with type D bulbs. Twenty-four bulbs were discharged into the engine during a cranking time of 240 seconds at 137 R. P. M. and the engine failed to start. Four type A bulbs were then discharged into the engine at the same cranking speed and it started in 30 seconds.

To illustrate the superior effectiveness of a priming fuel which comprises liquid and gaseous components in comparison with that of the liquid component thereof used alone, starting tests were made in a cold room on a 2 stroke cycle, 6 cylinder diesel engine of 4% inch bore and 5 inch stroke rated at 225 horsepower and 2100 R. P. M. maximum speed. This engine has proven difficult to start on normal diesel fuels at |20 F. The engine had connected to the intake manifold a discharger for the pressurized bulbs and also a device by which the liquid component alone could be manually pumped in atomized form into the system. The liquid component of the priming fuel as detailed in the formula set forth hereinbefore was employed for test purposes.

With the engine at approximately 2 F. an attempt was made to start it with the liquid component of the fuel, wherein 51 ml. of the liquid were pumped into the engine before and during cranking. The engine did not start during a thirty second cranking period. However, when bulbs containing the liquid component and methane under pressure were used, the engine was started on two bulbs (approximately 20 cc. of fuel) in 5 seconds cranking time.

As a further exemplification of this invention, the liquid component of the priming fuel has been combined with ethyleen as the gaseous or vaprous component, and bulbs similar to those described have been made in which the liquidcontent comprises the constituents of the formula detailed heretofore and the gaseous component was ethylene. Ethylene is readily soluble in ethyl ether, and has a range of flammability at about F. and l atmosphere pressure from about 2.75 to 28.6 on a percentage by volume basis when mixed with air. Such bulbs were tested in a 4 cylinder 4 stroke cycle diesel engine of 4 /2 inch bore and 5 /2 inch stroke, rated at 48 horsepower at 1200 R'. P. M. At approximately 30 F. the engine was started by seven bulbs in 60 seconds cranking time at 128 R. P. M.

As has been stated heretofore the concept of this invention encompasses starting fuels for internal combustion engines of all types, and because the specific examples ofengine operations set forth above are limited to diesel engines, it is not intended that the invention be limited to'diesel engine operation. To illustrate the advantages of priming fuels made in accordance with this invention when applied to gasoline engine operation, comparative tests of priming fuels were made on such an engine in a cold room. For this purpose 'a four cylinder, four stroke cycle gasoline engine of 3% inch bore and 3 /2 inch stroke, rated at 15 horsepower at 3000 R. P. M. was used. A discharger for pressurized bulbs Was connected to the intake manifold of the engine.

Similar steel bulbs, each containing approximately 7.5 cc. of the liquid starting fuel component detailed hereinbefore combined under pressure with, respectively, CO2 gas, methane, and ethylene, were compared for their relative abilities to initiate starting of the gasoline engine. With the cold room at approximately 40 F. seven bulbs having a C02 content were discharged into the engine during a cranking period of 126 seconds at 239 R. P. M. Without starting of the engine being initiated. Under comparable temperature conditions two bulbs having a methane content initiated starting in 8 second cranking time at 241 R. P. M., and on a separate test three bulbs having a methane content initiated starting in 39 seconds cranking time at 241 R. P. M. Still under comparable temperature conditions, three bulbs having an ethylene content initiated starting of the engine in 84 seconds cranking time at 253 R. P. M.

On other and different tests from those delineated above, and using other gasoline engines, starting has been accomplished in cold rooms at temperatures as low as 65 F. with bulbs containing the previously detailed liquid component and ethylene gas under pressure.

It is not intended that this invention be limited to the specific substances, proportions, or conditions set forth in the above described exemplary embodiments thereof. Other flammable gases or vapors than those above specified which may be used as the gaseous constituent of the priming fuel are, by way of example, ethane, acetylene, and hydrogen. Also bulbs of priming fuels have been made in accordance with this invention whereinpressures exceeding 1200 pounds per square inch were employed on the gaseous medium. Therefore it is intendedthat the invention embrace all equivalents within the definitions of the appended claims.

I claim:

1. A priming device for an internal combustion engine of the recoprocating piston type comprising a charge of priming fuel for combustion under compression in an internal combustion engine, said charge beingv maintained under superatmospheric autogenous pressure in a sealed the form of a finely divided spray of diethyl ether and flammable gas into the air intake system of an internal combustion engine when said closure is perforated where said spray is mixed with air to form a combustible mixture and thence delivered into the cylinder upon cranking of the engine to be fired after compression therein thereby starting the engine.

2. The invention defined by claim 1 wherein the flammable gasis methane.

3. Theinvcntiondefined by claim 1 wherein the llammable gas is natural gas.

4. The invention defined by claim 1 wherein the flammable gas is ethylene.

5. The invention defined by claim 1 wherein the flammable gas is acetylene.

6. The invention defined by claim 1 wherein the flammable gas is hydrogen.

7. The invention defined by claim- 1 wherein the diethyl ether is present in the form of a liquid component containing 60% to 95% by volume of diethyl ether, 1% to 5% by volume of methyl alcohol, and 5% to 30% by volume of a propylene oxide polymer of lubricating viscosity.

References Cited in the file of this patent UNITED STATES PATENTS 1,990,499 Odell Feb. 12, 1935 2,364,356 Greathou'se Dec. 5, 1944 2,404,094 Robertson July 16, 1946 2,431,322 Goodale Nov. 25, 1947 2,516,787 Moody July 25, 1.950 2,559,605 Drouilly July 10, 1,951 2,575,543 Young Nov. 20, 1951 2,601,211 Neely June 17, 1952 FOREIGN PATENTS 2,252 Great Britain Jan. 28, 1913

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