CA1052643A - Method of oxidizing fuels in internal combustion engines - Google Patents

Abstract

SPECIFICATION

DONALD E. VIERLING and HOWARD S. ORR
A METHOD OF OXIDIZING FUELS

ABSTRACT OF THE DISCLOSURE

A method of substantially completely oxidizing a fuel in a combustion chamber of an engine in which a mixture of oxygen, air and exhaust gases is added to the fuel. The proportions by weight in the mixture are between 4 and 16% oxygen, between 85 and 25% air and between 11 and 59% exhaust gases from the combustion chamber. The fuel and mixture in these proportions are fed to the combustion chamber during substantially all operation of the engine.

Description

This invention relates to a method of oxidizing fuels such as hydrocarbons, hydrogen, carbon and carbon monoxide and more particularly to burning gasoline or hydrogen in an automobile engine with a reduction in the amount of toxic substances produced.
It is well known that toxic nitric oxides are formed when fuels are oxidized in the presence of air. When hydrocarbons are oxidized other toxic substances, particularly carbon monoxide and unburned hydrocarbons are also usually formed. The situation is such that legal standards have been adopted by the United States Government limiting the percentage of nitric oxides, carbon monoxide and unburned hydrocarbons which may be discharged from automobile engines to the air. To meet these standards numerous ., _I_ : ,:: : : ::: - : : . - . , :
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Il 1 105~643 ¦ devices and methods have been proposed and some have been installed ¦ on automobiles. Those commonly used consist mainly of catalysts ¦ and filters which are costly to install and maintain. In addition ¦ they reduce the engine efficiency so that the gasol~ne consumption ¦ per mile increases as much as 50%. Thus the reduction in air pollution is much less than hoped for and the energy crisis is expanded.
Other systems have been suggested such as shown in Cettin et al Patent No. 3,709,203 dated January 9, 1973, 1~ Cooper ~ atent No. 3,792,690 dated February 19, 1974 and Nakajima et al~Patent No. 3,817,232 dated June 18, 1974. The systems disclosed therein overcome some of the disadvantages of the other systems, but they are relatively expensive to install and operate.

It is therefore an object of our invention to provide a method of oxidizing hydrocarbons, particularly in a gasoline ~; engine, which reduces the total amount as well as the percentage of toxic materials produced without reducing engine efficiency.
, Another object is to provide such a method which is relatively inexpensive to install and operate.
These and other objects will become more apparent after referrlng to the following specification and drawings, in which the single Figure shows apparatus suitable for carrying out our method.

Referring more particularly to the drawings, reference numeral 2 indicates an oxidizing or combustion chamber, such as a gasoline engine. Fuel, such as gasoline, is fed from a tank 3 . through a temperature control 4 and valve 5 to a proportional mixer 6. Commercially pure oxygen is also fed to the mixer 6

- 2 - Vierling and Orr l ~05Z643 ¦ throuqh valve 7 from an oxygen storage tank 8, having a heating chamber 9 which is used to vaporize the oxygen when it is in liquid form. Exhaust gases pass from chamber 2 through a conduit l 12. A pressure control valve 14 in conduit 12 bypasses part of the hot exhaust gases from conduit 12 to the heating chamber 9 of tank 8 through conduits 16 and 18 in order to vaporize the oxygen. The operation of valve 14 is controlled by a pressure control line 20 leading from the tank 8.
An air conduit 24 with a shut-off valve 26 therein leads to the mixer 6. A pressure control valve 28 in conduit 12 controls flow of exhaust gases through conduit 30 and cooler 32 to a tank 34. A pump 35 is installed in conduit 30 to obtain the desired pressure. Pressure in tank 34 controls operation of valve 28 through lead 36. A conduit 38 having a shut-off valve 40 therein leads from tank 34 to mixer 6. If desired, the flow of the fuel may be controlled by a temperature control valve 42 operated by the temperature in chamber 2 to prevent overheating.
In operation, valves 26 and 40 are opened. The mixer 6 and the flow of fuel, oxygen, air and exhaust gases thereto are adjusted so that the amount of nitric oxide in the exhaust gases i will be within acceptable limits and so that the heat produced in chamber 2 will be sufficiently low to prevent deterioration of the chamber. The fuel-oxygen ratio is adjusted so that most of the fuel will burn to carbon dioxide and steam. In order to reduce the amount of nitric oxide to acceptable limits it is necessary that the mixture of air, oxygen and exhaust gases which are substantially inert must be in the proportions of 85%, 4% and , 11~ by weight. In order to operate at acceptable temperatures and also to have efficient operation it is necessary that these proportions be changed to 25% air, 16% oxygen and 59%
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- 3 - Vierling and Orr ~05'~643 exhaust gases and that the engine be run substantially at all times within the two limits. Any combination within the upper and lower limits of each addition may be used. Operation for any extended period outside the ranges will result in too much pollutic n, high costs or engine damage. It will be seen that in this operation the inert gases are partially in the form of nitrogen and partially in the form of exhaust gases, while a large part of the oxygen is supplied in the air. In addition if the fuel is not completely burned it will be recycled through the chamber 2, thus giving it additional chances to burn and reducing the amount of carbon monoxide and unburned hydrocarbons exhausted to the atmosphere.
While one embodiment of our invention has been shown and described, it will be apparent that other adaptations and modifications may be made without departing from the scope of the f 1~wing claims.

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- 4 - Vierling and Orr

Claims (4)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN
EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. The method of substantially completely oxidizing a fuel in an engine having a combustion chamber which comprises adding to said fuel a mixture of oxygen, air and exhaust gases, individually controlling the flow of oxygen, air and exhaust gases, so as to provide a mixture in which the proportions by weight are between 4 and 16%
oxygen, between 85 and 25% air, and between 11 and 59%
exhaust gases from said combustion chamber, feeding said fuel and controlled mixture to said combustion chamber and burning the fuel and mixture therein, and continuing addition of said fuel and controlled mixture to said combustion chamber during substantially all operation of said engine.

2. The method of claim (1) in which the fuel is hydrogen.

3. The method of claim (1) in which the fuel is of the class consisting of hydrocarbons, hydrogen, carbon and carbon monoxide.

4. The method of claim (3) in which the fuel is hydrogen.