GB2073312A - Steam raising to supply an IC engine air intake - Google Patents

Abstract

An engine vacuum controlled valve (32, 42) meters small amounts of water to a vaporisation chamber (56) mounted on the engine exhaust manifold (14) whereby small amounts of superheated steam are passed at virtually all times of the engine operation from the chamber (56) via a pipe (60) into the engine intake system at a location well upstream of the carburettor (15), e.g. into the air cleaner housing (20), whereby any water condensing on engine switch-off is prevented from reaching the carburettor (15). A temperature-responsive switch (58, 59) associated with the chamber (56) controls the vacuum pipe 48 or the water pipe 28 by a solenoid valve (50). <IMAGE>

Description

SPECIFICATION Apparatus for raising steam and introducing it into internal combustion engines The present invention concerns apparatus, saleable in kit-form, for raising steam and introducing it into internal-combustion engines, and such apparatus when installed in an internal combustion engine e.g. a motor car engine. The invention also includes a vacuumcontrolled water flow control device or "carburettor" for controlling the flow of water into a steam raising device forming part of the present system.

It is known from the prior art to introduce steam into internal-combustion engines for which various advantages have been adduced such as reduction in the exhaust gas pollutant content and reduction in the octane requirement of the engine to enable lower leadcontent petrol to be employed. Other reasons mentioned included the benefits of moistening the charge and to increase the mass flow. In yet another prior proposal for injecting steam hydrogenation of the mixture was said to be the aim.

The prior art proposals did not address themselves to the problem of improving the vaporization of the normal air-fuel mixture and better atomization of the fuel by the supplying of additional heat to the fuel through the steam. Moreover, the prior art steam injection systems suffered from the drawbacks of producing steam in situ in the combustion chamber, or adjacent thereto which involved the problems of heat transfer when the water is converted into steam. This had a tendency to cause damage to inlet valves. In other prior proposals the steam was generated a long way from its intended injection point and on its way was permitted to cool to such an extent that it condensed to water and produced corrosion problems.

Yet another prior art proposal involved the problem of boiling large volumes of water leading to high water consumption rates, the inherent safety problem of a storage vessel or tank containing boiling water at pressure and the problem of continuous or intermittent replenishment.

The present invention seeks to improve the efficiency of vaporisation of the fuel whereby to reduce fuel consumption and to overcome or reduce the drawbacks of and objections to the use of steam by using throughout only very small and controlled amounts of superheated, not wet, steam which virtually cannot condense downstream of the location of vaporisation of water and which is so constructed that in effect no water can pass into the carburettor to cause corrosion problems.

According to one aspect of the present invention, there is provided apparatus, saleable in kit form, for introducing steam into an internal-combustion engine comprising a water flow rate control device connectable to a source of water and adjustable to any desired value of flow rate of the water from the water tank; a vaporisation chamber;a valve connected to receive water from said device and connectible to the intake side of the said engine, said valve being responsive to reduced pressure from said intake side to permit or prevent water to pass from the tank to the vaporisation chamber, said vaporisation chamber being mounted at or sufficiently close to a part of the exhaust system of the internalcombustion engine to be heated thereby sufficiently to vaporise water to steam, a steam duct leading from the said vaporisation chamber into the intake system of the internalcombustion engine at a point upstream of the carburettor, and means for preventing any small droplets of water that may condense in said duct on switching the said engine off from passing into the carburettor.

Preferably the last-mentioned means may be a drain hole in the air cleaner housing in which the outlet of said steam duct terminates; alternatively, or additionally, the said means may include or may be constituted by the location of said outlet sufficiently far from the junction of the air cleaner housing and the pipe that leads therefrom to the carburettor.

Preferably the water flow adjustment device is a drip-adjuster in the form of a screwadjustable throttle. In an advantageous embodiment, or alternatively, according to another aspect of the invention, water flow rate control valve comprises a housing, a diaphragm across the housing to divide it into two chambers from one of which projects a rod carrying a valve member for co-operation with a seat-forming a water inlet into the housing, the other chamber containing a spring for biasing the diaphragm to its valve seat closing position, said chamber being open to engine suction and a water outlet whereby in operation flexing of the diaphragm in response to vacuum or reduced pressure in said chamber causes the rod to move towards or away from the valve seat to prevent or permit respectively, water to pass from the said inlet to the said outlet.

The pipe connected to the diaphragm valve contains in one embodiment of the invention, an electro-magnetic solenoid capable of obturating a pipe connecting said valve and the source of vacuum or reduced pressure, the solenoid valve being controlled in accordance with engine temperature, e.g. by a bimetallic strip mounted on the wail of the vaporisation chamber whereby to prevent suction from being applied to the valve housing and thus water from passing to the vaporisation chamber before the exhaust manifold has reached a predetermined temperature. The solenoid is preferably electrically connected to a relay interposed between the bimetallic strip con tacts mounted on the vaporisation chamber.

Accordingly in the present invention, since at virtually all times of engine operation (apart from the start-up period and at gear changes) there is engine vacuum, suction is applied to the diaphragm valve, to allow an extremely small amount of water to flow past the dripadjuster and the diaphragm valve and to pass into the vaporisation chamber where it is instantly evaporated as superheated steam, passes along the steam duct and issues through a nozzle into the air, the air clearner housing at a position spaced from the downwardly directed pipe leading to the carburettor venturr.

Naturally, for a multi-carburettor engine there is one such apparatus or kit per carburettor, although there may be a single vaporising chamber ("burner") with the appropriate number of steam outlets.

Thus the steam raising operation is operational at all times except during the brief period of start up until the solenoid opens to allow vacuum to be applied to the diaphragm valve and the very brief period indeed while the vacuum in the system collapses while gear change takes place. The diaphragm valve or water carburettor" thus controls the flow of very small amounts of water to the vaporisation chamber or "burner" and has a "pushpull" method of operation which is fully automatic. The main body of the diaphragm valve or water carburettor is sealed to allow a semivacuum operation to take place.When the system is shut off any residual amount of water in the pipe connecting the diaphragm valve to the exhaust vaporising chamber is immediately vaporised initially and as the vaporising chamber cools it merely collects in the bottom of the chamber without being allowed to pass into the intake system. The small amount of steam that is still vaporised passes up into the air cleaner housing and since the amount of steam being passed along at all times is extremely small only a very few droplets of water may condense with the air cleaner housing in an amount quite insufficient to cause corrosion and quite unable to pass into the carburettor for the next start-up.

As already mentioned, a drain hole may be provided for the air cleaner.

The invention will be described with reference to the accompanying drawings which illustrate preferred embodiments of the invention.

Figure 1 is a "system" view or schematic layout of an internal combustion engine fitted with the steam-raising apparatus of the present invention; Figure 2 is a circuit diagram of the electrical components associated with the system shown in Fig. 1, and Figure 3 is a modified circuit diagram of another embodiment of the electrical system.

Referring to the drawings, there is provided a steam raising apparatus 10 for introducing controlled, small amounts of steam into an internal-combustion engine 11, preferably for a motor car. The engine is illustrated generally by reference to an engine block 12, inlet manifold 1 3 and exhaust manifold 1 4. A carburettor 1 5 of the venturi and butterfly type is also shown schematically including a fuel pipe 1 7. Air for combustion is sucked in by an inlet pipe 1 8 through an air cleaner housing 20 provided with a filter 21.

A water tank 22 has a filler cap 24 and a filter 26 from which extends a small-bore water pipe 28. The water pipe 28 is provided with a manually adjustable screw 30 serving as an obturator or dripper so that in effect a very small amount of water flows past the dripper 30 into a water inlet port 32 formed as a valve seat at one end of the housing 34 of a diaphragm valve 36 which will also be referred to as a "water carburettor". Co-operating with the port 32 is a rubber washer 38 backed by a metallic washer 39 mounted at the end of an operating rod 40 attached to a diaphragm or membrane 42 arranged across an enlarged section of the housing 34. The diaphragm 42 is biased by a spring 43 towards its position wherein the water inlet port 32 is sealingly closed by the washer 38.The washer 38 controls the flow of water from the inlet port 32 into a water outlet port 45. The valve housing is povided adjacent the end of the spring 43 remote from the diaphragm 42 with a vacuum port 46 continued as a vacuum or suction pipe 48 open at its other end to the interior of the carburettor 1 5.

Inserted in the vacuum pipe 48 is a T-piece 49 connected to the distributor and thus open to the vacuum. However, as an optional feature, the vacuum or suction pipe 48 is also provided with a solenoid-controlled obturating valve 50 which can permit or prevent, depending on its position, and in the manner described below, the application of suction of the diaphragm 42.

Reverting to the water outlet port 45, it continues as a pipe 52, the outlet of which terminates in a small metallic hollow cylinder, herein referred to as the burner or vaporising chamber 56 which is closed at the bottom end and is secured on the exhaust manifold 14 of the engine. The drops of water passing from the tank 22 past the dripper 30 and the washers 38 of valve 34 drop into the burner 56 where they are instantly vaporised to form superheated steam.

In the embodiment where the solenoid-controlled valve 50 is provided, the housing of the vaporisation chamber or burner 56 is provided with a bimetallic strip 58 the contacts 59 of which are arranged to close when the temperature of the exhaust manifold 14 has reached a pre-set value whereby to close an electric circuit and energise the solenoid to open the pipe 48 to allow suction to be applied to the diaphragm 42. It will therefore be appreciated that before such time as it takes for the engine to get sufficiently hot no suction is applied to the diaphragm valve and therefore no water is dispensed into the burner 56 and thus no steam can be generated therein.

The outlet from the burner 56 is formed by a steam pipe 60 which terminates in a nozzle 62 inside the air cleaner chamber 20. This nozzle 62 is so disposed with respect to the tube 64 connecting the outlet of the air cleaner 20 with the carburettor 1 5 that any small droplets of water that may condense at the nozzle on switching off the engine will collect inside the air cleaner housing 20 and cannot pass into the said tube 64. A small drain hole schematically indicated at 66 may also be provided.

In fact, on engine switch-off, suction is applied via 64, 20, 60 and 56 to the water pipe 52 and thus very little, if any, water can pass into the burner 56 for vaporisation and subsequent condensation. Here one must bear in mind also the role of the dripper 30 allowing only a very small water flow rate.

Figure 2 shows one embodiment of the electrical circuit associated with the apparatus described in Fig. 1. The battery associated with the motor vehicle internal-combustion engine is shown only schematically at (70) and is associated with a relay 71 one terminal of which goes to the ignition switch (72), another to the usual condenser 73, and the other side of which is earthed. The bimetallic strip 58 fixed to the wall of the burner 56 is connected to the same terminal of the relay 71 as the condenser 73. Of course, the bimetallic strip could be replaced by a thermocouple.

From the relay 71 a connection is made to the solenoid 50, the other side of which is earthed. An optional connection may be made to a warning light 75 and to an electric fan 76.

It is emphasized, however that the electrical components of the system or kit are purely optional and it would be perfectly possible for the system or kit to operate efficiently and well without the solenoid since as already stated above, the amount of water being vaporised at any one time is very little and the nozzle is so far from the pipe leading to the carburettor that the chances of water from condensation of steam passing into the carburettor to cause expensive corrosion problems is highly reduced or eliminated.

Fig. 3 shows an alternative embodiment in which like parts have been designated by like reference numbers. In this embodiment, there is no vacuum solenoid but instead the dripper is replaced by an electric water metering or dosing valve 80 connected upstream of the diaphragm valve 36-42.

It will accordingly be appreciated that the present invention provides an extremely simple and reliable system for adding dry superheated steam to the conventional fuel-air mixture in an internal-combustion engine in which the hot steam is used for better vaporisation of the fuel and thereby greater combustion efficiency and savings in economy. In view of the very small amount of steam utilised there is no problem in safety in that there are no large amounts of water boiling; moreover, corrosion problems are substantially eliminated because of the location of the parts and the way in which water is substantially prevented from reaching the carburettor intake.

The beneficial effect of the steam is exploited throughout substantially the entire operating range of the engine and the amount of water vaporised is so small that substantially no problem arises with regard to replenishing the water tank in that long journey can be undertaken, with the use of a water tank of no greater volurne that that of a screen-wash bottle, for which there should be no problem of accommodation within the engine compartment of a motor vehicle.

In a non-illustrated embodiment, the "burner" 56 may be provided with a windshield to prevent the air flow induced by the usual cooling fan from cooling the "burner" 56.

The bimetallic strip could be dispensed with and the water valve 80 or the solenoid valve 50 could be controlled by a timing device, relay or the like.

Purely by way of example and not of limitation, the following dimensions and parameters may be given as typical: the outside diameters of water pipe 28, vacuum or suction pipe 48 and steam pipe 60 are 6 mm, 3mrn and 1 9mm respectively; the capacity of the water tank 22 is 3 2 pints (2 litres); water consump- tion 100 miles/pint (282 km/l); and the horizontal distance (as viewed in Fig. 1) between the outlet of nozzle 62 and the inlet to the pipe 64 leading to the carburettor venturi may be between about 1" (2.5cm) and and about 6 (46 cm). With these dimensions and parameters, a motor could thus travel some 350 m (563 km) without the need to replenish the water tank. Of course, even if the water tank were emptied in spite of the fact that the warning light 75 would be lit, the vehicle could safely be operated without steam.

Claims (11)

1. Apparatus or kit of parts for raising steam for use in improving the vaporisation of liquid fuel in an internal-combustion engine, the apparatus comprising a pipe connec.able or connected to a water reservoir; a control valve provided with a water inlet port connected or connectable to said pipe, a water outlet port, and a vacuum port connectable or connected to a source of engine vacuum, said valve being effective to prevent or to permit water to pass from the said water inlet port to said water outlet port in dependence upon the vacuum conditions in said engine; a vaporisation chamber adapted to be heated by the exhaust gases from the engine and to vaporise water received therein from said outlet port, a steam pipe connectable to the vaporisation chamber and connectable to terminate or terminating in the air intake system of the internal combustion engine at a position upstream of the fuel-air carburettor of the latter, and means effective, on engine switch-off, to prevent water of condensation from passing into said carburettor.

2. Apparatus or kit according to claim 1, wherein the last-mentioned means is a drain hole in the air cleaner housing in which said steam pipe terminates.

3. Apparatus or kit according to claim 1 or 2, wherein said means is constituted by the location of the outlet of the steam pipe sufficiently far from the junction of the air cleaner housing and the pipe that leads from it to the carburettor.

4. Apparatus or kit according to any preceding claim, wherein the said control valve is a diaphragm valve open on one side to engine vacuum and carrying on its otherside a resilient sealing member movable on flexing of the diaphragm towards and away from the water inlet port.

5. Apparatus or kit according to any preceding claim, wherein the steam pipe from the vaporisation chamber terminates in a nozzle located inside the air cleaner housing of the engine but spaced from the pipe connecting the air cleaner housing outlet with the air inlet carburettor.

6. Apparatus or kit according to any preceding claim, wherein a drip adjuster is interposed within the pipe connecting water reservoir to the said valve.

7. Apparatus or kit according to any preceding claim, wherein the drip adjuster is an electrically controlled valve, the valve being operated in response to engine temperature so that no water may pass therepast before the engine has reached a sufficient temperature.

8. Apparatus according to any one of claims 1 to 6, wherein a temperature-sensitive valve is provided in the suction pipe connecting the engine intake with the said diaphragm valve, said temperature-sensitive valve being adapted to close the suction pipe when the engine temperature is below a predetermined value.

9. Apparatus according to claim 6 wherein said temperature-sensitive valve is controlled by a bimetallic strip or like thermo-electric device mounted on the vaporisation chamber.

10. A control valve for controlling the amount of water that may pass in a water circulation system independently of the vacuum conditions in an internal combustion engine, said valve comprising a housing divided into two chambers by a flexible diaphragm, one chamber having a water inlet provided with a diphragm-movement-transmitting rod at the end of which is a resilient sealing member adapted to engage with or disengage from a water inlet, a water outlet from said housing spaced from the water inlet, and a spring in the other chamber for biasing the diaphragm into a water inlet-closing position, the other chamber having an outlet port connectable to the intake system of the engine so that when vacuum prevails therein the diaphragm flexes to uncover the water inlet port.

11. Apparatus or kit according to claim 1 substantially as herein described in Figs. 1 and 2 or Fig. 3 of the accompanying drawings.

1 2. An internal combustion engine provided with apparatus or kit according to any preceding claim.