GB2078297A

GB2078297A - Internal combustion engines

Info

Publication number: GB2078297A
Application number: GB8107855A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-06-17
Filing date: 1981-03-12
Publication date: 1982-01-06
Also published as: GB2078297B

Abstract

It is known from United Kingdom Patent Specification No. 1,513,051 to provide an internal combustion engine with a supply of a "mineral oil" paraffin, kerosene or white spirit in a vaporised condition, with the customary petrol/air mixture, to drive the engine. As the temperature(s) to which the "mineral oil" is heated to vaporise it was lead to residue build-up and eventual blockage of the tubing, the present invention provides coaxial tubes 9 between the "mineral oil" tank 8 and a trap 10, said tubes 9 extending into the exhaust manifold to effect vaporisation of the oil, the outertube being of stainless steel and the inner tube being of copper. This avoids "cracking" of the "mineral oil" and therefore prevents blockage of the tubing. <IMAGE>

Description

SPECIFICATION Internal combustion engine This invention relates to internal combustion engines.

One object of the present invention is to improve upon the engine disclosed in our earlier United Kingdom Patent Specification No. 1,513,051, and another object of the present invention is to improve the performance of a compression-ignition engine.

The term "mineral oil" as employed herein covers only paraffin, kerosene and white spirit.

Accordingly, the present invention consists in a multi-cylinder internal combustion engine having means operable to feed fuel to the engine, a tank for the storage of a quantity of a mineral oil (as defined above), a trap connected directly to said tank by first piping which consists of coaxial tubes of stainless steel and copper with the copper tube being disposed within the stainless steel tube, second piping connecting the trap to the cylinders of the engine by way of an intermediate element, third piping connecting the trap directly to the tank, and means operable to heat a part of the length of said first piping in order to vaporise at least some of the mineral oil which flows into said first piping from the tank, whereby, in use, vaporised mineral oil is drawn into said intermediate element and becomes mixed with at least air, any mineral oil which is in its liquid phase being returned directly from the trap to the tank by way of said third piping.

The feed of said mineral oil from said tank to said means may be effected by gravity; alternatively, said feed may be effected by an electric pump.

In a preferred embodiment of said engine, said means is an exhaust manifold which is connected to the exhaust ports of said engine, said part of said first piping being enclosed by said exhaust manifold.

In a spark-ignition i.c.e., said intermediate element is a carburettor and said vaporised mineral oil becomes mixed with a combustible mixture of vaporised petrol and air. In a compression-ignition i.c.e., said intermediate element is an air intake device such as an air intake manifold.

The present invention will now be more particularly described with reference to the accompanying diagrammatic drawing which illustrates one generally preferred embodiment by way of example only. In said drawing, there is illustrated a cylinder head 1 of a four-cylinder internal combustion engine whose cylinders are indicated by the reference numerals 2, 3,4 and 5. Each cylinder has an inlet port and an exhaust port. As illustrated, the exhaust ports of cylinders 2 and 4 are the left-hand ports whereas the inlet ports of the cylinders 2 and 4 are the right-hand ports. Also, as illustrated, the exhaust ports of the cylinders 3 and 5 are the right-hand ports whereas the inlet ports of the cylinders 3 and 5 are the left-hand ports.This well-known arrangement permits the inlet ports and two of the exhaust ports to be "siamesed", the inlet ports being connected to an inlet manifold 6 which has onlytwo branches and the exhaust ports being connected to a threebranched exhaust manifold 7.

A tank 8 for the storage of, for example, one litre of a mineral oil (as defined above) is connected to one end of a length of piping 9 which consists of seamless stainles steel tubing in which there is coaxially arranged a length of copper tubing. The opposite end of the piping 9 is connected to a trap 10 which has a cap 11 to which is fitted one end of piping 12 whose other end is connected to the cylinders of the engine by way of an intermediate element. Said intermediate element is a carburettor (not illustrated) if the engine is of the spark-ignition type but may be an air intake device (for example, the manifold 6) if the engine is of the compressionignition type. The carburettor may be mounted, for example, on the inlet manifold 6 equidistantly from the branches thereof. The trap 10 is connected directly to the tank 8 buy a pipe 13.

The piping 9 is of such length as to enable the portion thereof intermediate its ends to be caused to extend inside the exhaust manifold 7 to a location whereat the burnt gases are very hot, if not at their highest temperature(s). Thus, it will be seen that said piping 9 has been illustrated as having been shaped into a loop 14 which is disposed within the middle branch of the three branches of the exhaust man ifold. In one embodiment, the stainless steel tubing is 3/16 inch outside diameter, 24 gauge, whereas the copper tube is 1/8 inch outside diameter, 20 gauge; this combination of coaxial tubing is applicable to engines up to and including 1100 cc capacity.In another embodiment, the stainless steel tubing is 1/4 inch outside diameter, 24 gauge, whereas the copper tube is 3/16 inch outside diameter, 16 gauge; this combination of coaxial tubing is applicable to engines of larger capacity than 1100 cc. These two examples of coaxial tubing combinations are not to be taken to be exhaustive of the possible combinations of tubing sizes/dimensions.

In operation, a liquid mineral oil (for example paraffin) is fed by gravity into the piping 9 and, as the liquid paraffin passes along the piping 9, it is heated and becomes at least partially vaporised by heat exchange between the burnt gases issuing from the exhaust ports and the piping 9. The vaporised paraffin and any paraffin which is still in liquid form is fed into the trap 10. Any paraffin in liquid form is returned by gravity directly to the tank 8 by way of the pipe 13 whereas the vaporised paraffin is drawn from the trap 10 into the intermediate element to be mixed with the combustible mixture of vaporised petrol and air in the case of a spark-ignition engine or with air in the case of a compression-ignition engine.

It has been found, from extensive road tests which we have made, that the exhaust gases emitted from the exhaust pipe into the atmosphere are very clean and certainly well below pollution-producing levels.

We attribute the improved thermal efficiency of the engine to the metered induction of the vaporised paraffin. Moreover, we estimate that one litre of paraffin is sufficient for over 4000 miles of motoring.

We found that "flooding" could occur in the arrangement disclosed in Patent Specification No.

1,513,051 when the needle valve 13 and the float 14 of that prior arrangement were used. The elimina tion of said needle valve and float has cured that problem. Moreover, we found that "cracking" of the liquid mineral oil occurred at certain temperatures and that this resulted in a build-up of residue which led, in turn, to eventual blockage of the piping.This latter disadvantage has been avoided by the use of the coaxial tubes constituting the piping 9 because (a) the use of two coaxial tubes has meant that the heat of the exhaust gases becomes dissipated by the two thicknesses of metal of the inner and outer tubes, with the result that the temperature within the inner tube is high enough to vaporise the mineral oil without "cracking" it, and (b) the copper of the inner tube is a good conductor of heat which achieves quickvaporisation of the liquid mineral oil whilst the stainless steel of the outer tube is able to withstand the high temperatures occurring in the exhaust manifold and thus protect the copper tube against erosion.

In a spark-ignition engine, the piping 12 is connected at the air-intake of the carburettor, namely, upstream of the jet through which the petrol is supplied to the choke tube or venturi. It is thought that sufficiently good results could be obtained if said piping 12 were to be connected downstream of said choke tube.

Referring again to the drawing, if the particular vehicle in which the additional equipment is to be installed does not have space sufficient to permit the tank for the storage of the mineral oil to be placed to permit gravity-feed of said oil, an electricallyoperated pump may be connected in the piping 9.

When sold in kit form to the public, the kit would desirably include compression glands and any other items necessary to enable the vehicle owner to effect a proper and safe installation.

When used in connection with a spark-ignition engine having twin carburettors, the other end of piping 12 will be connected to each carburettor by means of a T-piece.

The Claims defining the present invention are not intended to provoke contravention of the Hydrocarbon Oil (Customs & Excise) Act, 1971 and any use of the present invention which will contravene said Act is hereby disclaimed.

Claims

1. A multi-cylinder internal combustion engine having means operable to feed fuel to the engine, a tankforthe storage of a quantity of a mineral oil (as defined above), a trap connected directly to said tank by first piping which consists of coaxial tubes of stainless steel and copper with the copper tube being disposed within the stainless steel tube, second piping connecting the trap to the cylinders of the engine by way of an intermediate element, third piping connecting the trap directly to the tank, and means operable to heat a part of the length of said first piping in order to vaporise at least some of the mineral oil which flows into said first piping from the tank, whereby, in use, vaporised mineral oil is drawn into said intermediate element and becomes mixed with at least air, any mineral oil which is in its liquid phase being returned directly from the trap to the tank by way of said third piping.

2. An engine as claimed in Claim 1, wherein the relative positions of the tank and said means operable to heat a part of the length of said first piping are such that the feed of said mineral oil from said tank to said means is effected by gravity.

3. An engine as claimed in Claim 1, wherein the feed of said mineral oil to said means operable to heat a part of the length of said first piping is effected by an electric pump.

4. An engine as claimed in any one of Claims 1 to: 3 wherein said means operable to heat a part of the length of said first piping is an exhaust manifold which is connected to the exhaust ports of said engine, said part of said first piping being enclosed by said exhaust manifold.

5. An engine as claimed in any one of the preceding Claims, wherein said intermediate element is a carburettor and wherein the engine is a spark-ignition engine.

6. An engine as claimed in any one of Claims 1 to 4, wherein said intermediate element is an air intake device and wherein the engine is a compressionignition engine.

7. A multi-cylinder internal combustion engine, constructed, arranged and operable substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.

8. Any features of novelty, taken singly or in combination, of the embodiment(s) of the invention hereinbefore described with reference to the accompanying drawing.