GB2256457A

GB2256457A - I.c.engine exhaust flow restriction.

Info

Publication number: GB2256457A
Application number: GB9110355A
Authority: GB
Inventors: Iqbal Krishna Bharti
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-05-13
Filing date: 1991-05-13
Publication date: 1992-12-09
Also published as: GB9110355D0

Abstract

A plate 1 between the cylinder head 3 and the exhaust manifold 4 provides between the head and manifold exhaust passages a respective port 9 or ports (10, Fig. 3) of smaller cross-sectional area than the head port. A passage (15, Fig. 4) for the introduction of air may extend to the port (14) in a plate (13) in a pipe (12) connected to the common exhaust outlet pipe 16. <IMAGE>

Description

ANTI POLLUTION THERMAL REACTOR This invention relates to an antipollution therma1 reactor provided in the exhaust system of sn internal combs stion engine The internal combustion engine (hereafter re ferred to as engine) includes all types of spark ignition and compressson ignition engines either stationary or mount ed on any vehicle.

Reactor devices for use with the exhaust gas emission of an engine are known in the art such as described in Itali- an. Patent No. 315424 and U.S. Patent No. 1884915. The devic- es described in British Patent Nos0 623098, 287712 and 221302 for use with the exhaust pipe essentially ùnction as silencers All these devices, which are briefly referred in my Indian Patent No. 162176 are intended to reduce the extent of emission of hazardous pollutants entrained in the exhaust.

The Indian Patent No. 162176 describes an improved antipollu- tion reactor for use with the exhaust gas pipe of a vehicle engine comprising a circular plate or disc fitted by any kaswn manner to a pipe which is fixed to the exhaust gas pipe, the said plate or disc having a central axial opening or hole and a radial passage extending through the plate and terminating at the periphery of the said reactor pipe connecting said opening or hole to the atmosphere. Further it illustrates that the said dtsc has one or a plurality of secondary openings or holes, spaced around said central axial hole, each being connected to atmosphere by a radial passage extend- ing through the disc.

Pollution control devices such as catalatic conv erters are also known which are widely used in the world but these are not able to work with the fuel containing lead and hence lead free fuel is must. The antipollution devices as known in the art besides being costly and complicated in construction are able to control the engine exhaust polLution to a very limited extent.

Further the improved antipollution reactor of In dian Patent No. 162176 is mostly fitted at the Sree end of the exhaust pipe as when it is desired to be fitted at the exhaust manifold end, there is a space problem as sufficient space is not spared near the engine cylinder head in the vehicles.

Further, no engine developed so far throughout the world could achieve complete combustion inside the engine cylinder as all engines are producing CO (Carbon monoxide) and HC (Hydrocarbons) which are the products of incomplete combustion. However, these CO and HC are converted, latter on in the exhaust pipe by using catalatic converters into CO2. (Carbondioxide).

Here I would like to mention that till today, ma- inly carbon monoxide alongwith oxides of Nitrogen, lead and unburnt Hydrocarbons are only considered as hazardous pollutants in the engine exhaust emission, hence efforts have been made only to bring down the CQ level in the exhaust emission within the permissible limits, by supplying atmospheric air to burn the CO thus forming CO2 and hence nobody bothered for the increasing level of C02 in the engine exhaust emission.

But it is hibl time when we should bother for the level of CO2 in the engine exhaust emission considering a very large number of engines/vehicles being used in the world and the day by day irlcrease in their number along with other sources of combustion producing CO29 throughout the world and the world scientists are now very much aware about the global green house (ill) effect of increasin level of CO2 in the earths atmosphere, when CO2 layer thickness will increase further a time will come when the earth may have to face thE nuclear winter. Slerefore I am making continuous efforts to minimise the C02 level in the engine exhaust emission as cell as bringing down the level of hazardous pollutants such as CO and HC to almost nil.

In the existing engines during the exhaust stroke, it could not be possible so far, to remove all the burnt gases from the engine cylinder and thus some burnt gases consisting of CO2 are left out in the cylinder, which are at very high temperature during the next stroke (suction stroke) these burnt gases at high temp. are mixed with the fresh charge of air or air fuel mixture and due to the high temp. of left out burnt gases the fresh charge Increases in volume and lesser quantity of fresh charge occupies the whole cylinder volume .Thus not only a less charge is introduced during the suction stroke and the presence of left out CO2 dilutes the charge, giving low power after ignition during. the power stroke, but increase in volume of the fresh charge due to the high temp. of left out burnt gases very much disturbs the desired fuel air ratio, which is about 1:14 for petrol engines and 1:40 for diesel engines, resulting into an inconpiete combustion. The incomplete combustion not only decreases the engine power and increases the fuel consumption of the engine but also increases the smoke nuisance and increases the level of CO, C'02 aad unbnt Hydrocarbons in the exhaust emission.

The main obJect of this invention is to provide a thermal reactor in the exhaust system of the engine which is very simple in construction, easy in use and which sucks out all the burnt gases from the engine cy linger during the exhaust stroke and thus achieving complete combustion inside the engine cylinder resulting into a reduced level o! C02 (about 4.%) as well as CO and HC level almost nil, in the exhaust emission.

According to the present invention, there is provided an antipollution thermal reactor in the exhaust system of an internal combustion engine comprising a plate provided between the cylinder head exhaust port/ outlet and exhaust manifold of the engine, the said plate being provided with one hole against each exhaust port in the cylinder head and iherein the diameter of each hole in the said plate is smaller than the inside diameter of each of the exhaust port in the cylinder head.

Some specific embodiments of the present inve ntion will now be described by way of examples with reference to the accompanying drawings wherein : - Figure 1 shows in part sectional elevation, the thermal reactor fitted to the exhaust port in the engine cylinder head; Figure gt; shows in side view the thermal reactor fitted to the exhaust ports in the cylinder head of a multi-cylinder engine Figure? shows in side view, the thermal reactor provided with a plurality of holes to be adapted against each exhaust port in the cylinder head.

Figure 4- shows in sectional sideview a means of atmospheric air supply fitted on the exhaust pipe or manifold on down-stream side of the thermal reactor plate.

Referring to the figures of the draldng, the antipollution thermal reactor comprises a plate 1 pro-.

vided in the exhaust system of the engine between the exhaust port or outlet 2, in the cylinder head 3 and the exhaust manifold, 4. Fig.lalso shows engine block 5, piston 6, suction and exhaust valves 7 arid 8 respe otively and the cylinder-ll, other details like fuCl supply and ignition system have not been shown as are not required to understand the present invention. The plate 1 is provided with hole/s 9 such that one hole lies against each exhaust port 2. In a multi cylinder engine, the number of holes 9 are equal to the number of ports 2 and the spacing between the holes 9 depends upon the spacing of exhaust ports 29 The diameter 'd' of each hole 9 is smaller than the inside diameter 'D' of each exhaust port 29 Preferably diva. sd' may vary from 52% to 75,6 of the diva. 'D' and the thickness of the plate 1 may vary from 10 u to 25 m. The plate I may be of any shape like rectangular or eliptical.

A plurality of holes 10 as shown in fig. 3 may also be provided in plate iv instead of a single hole 9, against each exhaust port 2. In this case the too tal area of holes 10 should be less than the cross se ctional area of exhaust port 2. The thermal reactor consisting of the plate 1 provided with hole/s 9 is fitted in the leak proof manner with the help of gaskets and bolts (not shown) between the cylinder head 3 and the exhaust manifold 4.

During the exhaust stroke when the exhaust vao lve is opened the burnt gases are pushed by the piston into the exhaust port 2 in the cylinder head 3. And as the thermal reactor is provided between the port 2 and the exhaust manifold 4 the burnt gases have to pass through the hole 9 in the plate 1. Now while passing through the hole 9 the velocity of the burnt gases is increased too much due to contriction and thereby su efficient drop in pressur in the exhaust system is achieved which causes the sucking out from the cylinder 11, all the burnt gases.Thus there is complete scavenging and no high temp, burnt gases or CO are 2 left out in the engine cylinder and thus there is no heating or dilution of the fresh charge entering the engine cylinder during the next suction stroke and hence a proper fuel air mixture is maintained and Co- mplete combustion of the fusel is achieved inside the engine cylinder itself Though the construction and working of the thermal reactor of the present invention is very simple but the resuLt obtained by it are wonderful. Fu- el saving is 15% to 206, due to increase in thermal efficiency as well as volumetric efficiency.CO and HC levels in the exhaust emission are brought down quite below the permissible levels, which indicates that the complete combustion of fuel is taking place in the engine cylinder itself. CO2 emission is quite less about 4% only and smoke nuisance is also elimino ated thereby increasing the engine life. There is increase in engine power by- 40% or more and vehicle runs smoothly particularly in steep inclined gradient surfaces.

Further* particularly in case of a petrol engine an atmospheric air supply is provided in the exhaust system, down-stream side of the thermal reactor, plate l This air supply will burn the negligible remaining parts of CO and , thus making CO and HC level in exhaust em ission almost zero. The air supply means as shown in figo 4, consists of a pipe 12 fitted inside with a plate 13. The plate 13 is provided with an axial hole 14 and 2 radial hole 15 which is extended through the pipe 12 and connects the hole 14 to atmosphere.The pipe 12 is preferably fitted in a known manner to the common exhaust pipe 16 (shown in fig. l). The plate 13 may be provided more than one axial holes each being connected to the at- mosphere through radial passages/holes. Instead of radar al hole 15, a nipple may also be provided in its places The radial hole 15 or nipple (not shown) may be provided with a cock, which can be opened or closed in a known manner. When this cock is open air will be sucked from atmosphere to burn CO into C02 and C02 level in the exhaust will increase marginally. But if we want Co2 level in the exhaust low, the cock may be closed1 in that case there will be negligible amount of CO and HC in the exhaust emission.

While the present invention has been described and ilLustrated with reference to specific embodiments thereof, it will be understood that numerous modificati- ons may be made by those skilled in the art without actually departing from the scope of the claimed inven tion. Accordingly all modifications and equivalents may be resorted to which fall within the scope of the presto nt invention as claimed in the appended claim90

Claims

CLAIMS q) An antipollution thermal reactor provided in the exhaust system of an internal combustion engine comprising a pl ate provided between the cylinder head exhaust port/out- let and exhaust manifold of the engine, the said plate being provided with one hole against each exhaust port in the cylinder head and wherein the diameter of each hole in the said plate is smaller than the inside diam eter of each of the exhaust port in the cylinder head.
2) A thermal reactor as claimed in claim 1 wherein the dia meter of each of the hole in the said plate is 50% to 75? of the inside diameter of each of e exhaust port in the cylinder head.
3) A thermal reactor as claimed in claim 1 or 2 wherein the thickness of the said plate is 10 @@ to 25 wn.
4) A thermal reactor as claimed in claim 1 or 2 or 3 wherein the spacing between the holes in the said plate depends upon the spacing between the exhaust ports in the cylin der head, in case of a multicyLinder engine.
5) A thermal reactor as claimed in claim 1 or 2 or 3 or 4 wherein the said plate is fixed between the cylinder head and the exhaust manifold in a leak proof manner, with the help of gaskets and bolts or the like means.
6) A thermal reactor as claimed in claim 1 wherein the said plate is provided with a plurality of holes against each exhaust port in the cylinder head wherein the total area of the plurality of holes in the said plate is smaller than the area of each exhaust port.
7) A thermal reactor as claimed in any of the above cla ims wherein a means to supply the atmospheric air is provided in the exhaust system, downstream side of the said plate.
8) A thermal reactor as claimed in claim 7 wherein the said means comprises a pipe fitted inside with a plate te, an axial hole provided in the said plate and a radial hole/passage provided in the said plate exten ding through the pipe for sucking in the atmosphetic air.
9) An antipollution thermal reactor provided in the exh aust system of an internal combustion engine subs and tially as herein described and illustrated with refer rence to the accompanying drawings.
10) An internal combustion engine provided with antipollo ution thermal reactor in the exhaust system as claim ed in claims 1 to 9.