US1640690A - Treatment of internal-combustion-motor cylinders for carbon deposit - Google Patents

Description

beams-9C1 Patented Aug. 30, 927.

UNITED STA'F s CROSS REFERENCE JOHN F. GANNING, OF RIC HMOND HILL, NEW YOK TREATMENT OF INTEBNAL-COMBUSTION-MOTOB CYLINDERS FOR CARBON DEPOSIT.

Thisinvention relates to the treatment of cylinders of internal combustion motors to prevent, decrease, or remove the deposits which ordinarily form therein during the operation of the motor, commonly referred to as carbon; to reduce the tendency of the motor to knock from this cause, and to generally improve its operation. The invention comprises anovel composition of matter for the purpose and novel methods of introducing the same and of preventing or reducing the carbonaceous deposit in the cylinders.

In the operation of an internal combustion motor it is well known that owing to the actual combustion of the fuel in the cylinders and the very high temperatures resulting therefrom, there is a more or less rapid accumulation of deposit in the combustion spaces of the cylinders, around the valves, and upon the spark plugs, which seriously inteferes with the proper operation of the motor. This deposit, commonly referred to as carbon, tends to cause pre-ignition of the fuel charge in the cylinder resulting in the phenomenon commonly called a carbon. knock. This trouble has been so serious with the present grades of fuel that it has been necessary to design engines with materially lower compression ratios than would otherwise be desirable, which lowering of the compression decreases the power obtainable from an engine of given size. This deposit in the cylinders also fouls the spark plugs and at times renders them inoperative; and it also lodges upon the valves and valve seats and frequently prevents tight closing of the valves. i This deposit, while commonly referred to as carbon is not entirely carbon, but includes other foreign substances such as, in some instances, iron rust or metallic particles from the walls of thecylinder and piston, and generally a considerable portion of silica or other mineral matter due to 'dust from the road being drawn into the cylinders with the air entering the carbureter. The carbon element of the deposit is formed by soot resulting from incomplete combustion of the fuel, and also from a carbonization of the excess of lubricating oil which finds its way into the combustion spaces of the cylinders. The formation of the sooty part of the deposit is increased if too rich a mixture of fuel and air is used in the cylinder, and the amount and character of this lubricating oil may reach Application filed June 16,1928. Serial No. 645,916.

part of the deposit also varies with the constitutions of different types of gasoline or other fuel which may be used. An excess of the cylinders if the pistons are too loose, or if the design or construction of the pistons and rings is incorrect, or from other causes. The lubricating oil which reaches the combustion spaces of the cylinders is more or less decomposed by the high temperatures, and, in addition to itself providing a source of carbon, it appears when partially carbonized to act as a binder for the foreign elements in the cylinder, and under the high temperaturesit is consolidated with these other elements into a cake'or crust which frequently clings with' great tenacity to the piston head, cylinder walls and valves. In some instances this deposit is very hard and dry; and in other instances it is more or less soft and sooty, and frequently where there is an excess of oil reaching the engine cylinders, the deposit is greasy. The latter condition is very objectionable, as it tends particularly to foul the spark plugs and prevent proper ignition.

The composition of matter which I prefer to employ in accomplishing the objects sought by my invention includes an element, or elements, adapted to be absorbed by the carbon deposit, and to have a solvent action upon the ingredients of the deposit capable of being dissolved, especially the resinous or oily parts of the deposit which act as a binder for the other ingredients. This solvent element is also preferably of a combustible nature. Also included in the composition is an oxidizing agent, preferably one which will also have more or less of a solvent action, the primary purpose of the oxidizing agent being to cause the partially dissolved and loosened carbon with the solvent element which it has taken up, to burn under the high temperatures which occur in the cylinders during operation of the motor. For reasons which will be explained, I prefer to use a composition which is readily soluble in the gasoline or other. petroleum fuel used, and which will not in any way interfere with the proper explosion of the combustible charge in the cylinder, but will, if anything, tend to improve the burning of the charge. Such a composition may be introduced into the fuel and be carried into the cylinders with the fuel charge during the operation of the motor.

In its preferred form, my composition of FUEL & IGNITING DEVICES,

matter comprises entirely coal tar derivatives. The primarily solvent part of the composition consists of coal tar oils from which the tar acids have been substantially removed, and preferably including elements having a distri utive range of boilmg points, the greater portion of which preferably boils at a somewhat higher temperature than the larger part of ordinary gasoline. 'A

' amount of heavier coal tar oil of the fraction sometimes referred to as coal tar creosote oil, and boiling approximately between 150 C. and 350 C. As the primarily oxidizing agent of my composition, I may employ a nitrated coal tar derivative or other aromatic nitro compound, preferably nitrobenzol (or oil of mirbane as it is called commercially). The portions of the different elements of my composition may be considerably varied, but as an example of a composition which I find highly satisfactory, I may employ about 67% of the lighter coal tar oils, about l of the hea coal tar oils, and about 28 72, of the nitro enzol, (percentages by volume). The nitrobenzol has a more or less solvent actionupon the carbon deposit in addition to its oxidizing action, and the percentage of it employed may be considerably varied so long as enough is used to produce the desired oxidizing effect. Other oxidizing agents ma be substituted for it, but nitrobenzol is esirable, because it appears to be the most effective for the purposes intended, because it does not contain inorganic substances which might leave a residue, because it has a suitable boiling point and is not too volatile, and because it is readily soluble in the petroleum fuels commonly employed in internal combustion engines.

The coal tar oils mentioned are particularly suitable for the solvent element of my composition because they are very effective in eatin into the carbon deposit by more or less direct solvent action on the oily bindmg elements of the deposit, and are readily combustible in the presence of the oxidized agentso as to produce the burning off of the combustible parts of the deposit. By using oils having different or graded boiling points, it is possible to employ solvent -constituents of high boiling point, which will not volatilize quickly, but will remain in contact with the deposit so as to penetrate more thoroughly, and produce a more powerful action than is the case with more ighly volatile constituents. The lighter iiross Reference constituents however, in addition to their solvent and burning action, act as carriers for the heavier constituents, and enable them to more thoroughly permeate the deposit. The presence of lighter elements also promotes the proper volatilization or atomizing of the heavier constituents when introduced with the fuel into the carbureter and engine cylinders. Thelighter elements also carry the heavier into-the gasoline in the tank, and prevent such heavier elements from tending to separate out. A characteristic of the coal tar oils which makes them especially suitable for the purpose is that they do not themselves tend to detonate in the cylinders. Other oils could for some purposes be substituted for the coal tar oils mentioned; for instance, petroleum oils of similar boiling points can be employed, but are less eii'ective and would be less satisfactory, among other reasons because they would tend to themselves increase detonation in the cylinders.

Inmentioning the use of the difi'erent percenta es of the lighter and heavier coal tar oils, it will be understood that these percentages may be varied in accordance with the characteristics of the particular oils available. The high flash, solvent, or heavy naptha referred to, and the heavy coal tar oil, or coal tar creosote oil, having substantially the boiling points mentioned, are specified because readily obtainable in the market. As it is desirable not to have too high a proportion of the heavier oils, a much greater percentage of the naptha fractions is used than the heavier fractions. It might be possible to obtain a single coal tar distillate containing the proper range of fractions for use in my composition, but under present commercial practice, the described mixture is satisfactory.

My improved composition of matter may be introduced into the engine cylinders or brought in contact with the deposit in any suitable manner. For instance a small amount might be directly injected into each cylinder, or into the manifold. I greatly prefer, however, and it is one of the features of my invention, to introduce the substance into the engine cylinders by mixing it with the gasoline or other fuel before the same passes through the carbureter to the engine. For instance, in an ordinary gasoline operated automobile,-I merely pour a small amount of the composition into the gasoline in the ordinary storage tank. The proportion of the composition to the fuel can be considerably varied and will depend upon whether the composition is to be used in a new or clean engine, primarily for the purpose of preventing the formation of a carbon deposit, or whether it is to be used in a very dirty engine, in which case, a larger proportion should be employed. Or-

Search Room dinarily I find that the use of one part of the composition to about 640 parts of gasoline is sufiicient to procure satisfactory results in a new or clean motor, while under unfavorable conditions, I recommend the use of one part of the composition to about 320 parts of the fuel. A somewhat larger amount of the composition may be employed for certain conditions of carbon deposit without objectionable results. The composition may be employed steadily or may be used from time to time as needed, but I recommend that a small quantity of it be used at all times, preferably beginning before there is any deposit formed in the motor.

My preferred composition being entirely and readily soluble in petroleum fuels, is readily carburettable with a petroleum fuel such as gasoline. -When used with such a fuel it passes directly into the engine cylinders with the explosive mixture, and being somewhat less volatile than the gasoline it condenses more or less and is deposited on the walls of the combustion space where it attacks the deposit thereon.

A very efiective method of causing the composition to be brought into intimate contact with the surface of the combustion space consists in introducing the composition into the fuel as described and then, when stopping the motor, actuating the carburetor choker so as to leave the engine cylinders completely filled with a very rich charge of fuel with the composition carried thereby. This'provides a concentration of the composition sufiicient to cause it to act most effectively and thoroughly in permeating the carbon deposit while the engine is at rest. During this time, the soluble ingredients of the deposit will be dissolved or softened and u on starting the motor, the

softened and oosened parts of the de osit will be blown out by the explosions ta ing place within the cylinders and the high temperature produced will cause the combustible parts of the deposit to burn.

My composition appears to be most effective under the action of heat and therefore tends especially to keep the hottestthat when my composition is used in a cylinder in which the deposit is of an oily nature, as when there is an excessive amount of lubricating oil reaching the combustion space, this condition is quickly changed and the oiliness of the deposit disappears. This is particularly noticeable about the spark 'plugs which will be kept very clean.

For the purpose of improving the lubrication between the upper part of the pistons and the cylinder walls, where lubrication is often insufiicient, particularly in new motors, I ma introduce into my composition a lubricating ingredient, such. for instances, as a small amount of petrolatum or other heavy, non-volatile grease, soluble in the composition. A composition including such a lubricant may be advantageously employed, for instance, while the motor is bemg operated for its first two thousand miles, after which the composition may be utilized without the grease. The introduction of the lubricant into the engine cylinders with the composition is particularly desirable because the composition prevents the lubricant from tending to objectionably carbonize the motor and foul the spark plugs, a result which frequently occurs when it is attempted to introduce lubricant only with the fuel. For like reasons the composition with a lubricant may be advantageously used in the fuel of small boat engines, motor cycle engines, or other engines which are lubricated by introducing oil with the fuel.

The ingredients which I have mentioned as preferred for use in my composition are the most effective now known to me for the purpose, but it will be understood that other suitable ingredients capable of producing the same, or similar action, may be substituted.

What I claim is:

1. A- petroleum fuel additioned by a relatively small quantity of a carbon removing agent, consisting of coal tar distillates, from which the tar acids have been substantially removed, a relatively large portion of said distillates boiling between 130225 (3., and an oxidizing agent comprising a nitrated cyclic h drocarbon soluble in said distillates and sai fuel.

2. A composition of matter for treating internal combustion engine cylinders for carbon, consisting of a coal tar distillate boilin approximately between 130 and 225 i, approximately 67%; coal tar distillate boiling approximatel between 150 and 350 0., approximate y 4 92,; an nitrobenzol approximatel 28 75.

In testimony whereof I have affixed my signature to this specification.

JOHN F. CANNING..