GB2264073A

GB2264073A - "method of and apparatus for cleaning exhaust emissions"

Info

Publication number: GB2264073A
Application number: GB9202994A
Authority: GB
Inventors: Michael Taylor
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-02-13
Filing date: 1992-02-13
Publication date: 1993-08-18
Also published as: GB9202994D0

Abstract

Exhaust gases from an internal combustion engine first pass through a cooler, in the form of a heat exchanger before passing to a filter. The system preferably is a pressurized system with an appropriate expansion chamber. After being thus cooled, the exhaust gases are passed to a filtering stage which may comprise a passive filter or filters to trap solid particles and liquid droplets in the cooled exhaust gases. Downstream of the cooler and upstream of the passive filter, the system incorporates a scrubbing stage where, for example, the exhaust gases are bubbled through water whereby readily soluble pollutants and, to a significant extent, solid particles, are removed from the exhaust gases and left in the water.

Description

DESCRIPTION OF INVENTION Title: "Method of and apparatus for cleaning exhaust emissions" THIS INVENTION relates to a method of and apparatus for cleaning exhaust emissions from internal combustion engines.

It is already known to minimise the more environmentally damaging components of the exhaust emissions of an internal combustion engine, particularly of motor vehicles, by various means, for example by supplying a particularly lean fuel/air mixture to an engine having combustion chambers designed for efficient burning of such lean fuel/air mixtures (the so-called "lean-burn" approach) or by using so-called catalytic converters to receive the exhaust gases after they have left the engine combustion chambers and to convert noxious components of the exhaust gas to less noxious substances. The use of catalytic converters is currently favoured because it is capable, if used in conjunction with accurate control of the fuel to air ratio of the mixture supplied to the engine, of achieving a lower level of noxious emissions into the atmosphere than other methods.Unfortunately, the catalytic converter is an expensive item of limited life, adds significantly to the cost of operating an internal combustion engine and is, furthermore, readily "poisoned" by components which may be present in exhaust gases from an internal combustion engine, either as a result of human error (for example inadvertent use of leaded fuel) or of failure in the carburation management system.

It is an object of the present invention to provide an effective and economical means of reducing environmentally undesirable components from internal combustion exhaust gas emissions.

According to the present invention there is provided a means for removing pollutants from internal combustion engine exhaust gas emissions comprising cooling means for cooling the exhaust gases and filter means for subsequently filtering the cooled exhaust gases all without producing substantial back pressure.

In a preferred embodiment of the invention, exhaust gases from an internal combustion engine first pass through a cooler, in the form of a heat exchanger which may, for example, utilize engine coolant as a cooling fluid, or atmospheric air. In the case of a motor car or other vehicle powered by an internal combustion engine, such cooling air might conceivably be air circulated within the vehicle interior, whereby the heat exchanger could serve as a source of heat for the vehicle. Of course, no connection of the heat exchanger, used for cooling the exhaust gases, with the engine cooling system or the vehicle is necessary and in preferred embodiments the exhaust-gas-cooling heat exchanger is entirely self contained, without such connection. Of course, the system would preferably be a pressurized system with appropriate expansion chamber(s).

After being thus cooled, the exhaust gases are passed to a filtering stage which may comprise a passive filter or filters to trap solid particles and liquid droplets in the cooled exhaust gases, to prevent these from passing to the atmosphere. Preferably, downstream of the cooler and upstream of the passive filter, the system incorporates a scrubbing stage where, for example, the exhaust gases are bubbled through water whereby readily soluble pollutants and, to a significant extent, solid particles, are removed from the exhaust gases and left in the water. The water used in this scrubbing stage can be retained in the system for very lengthy periods because the water is being filtered. If necessary, this water may incorporate corrosion inhibitors. The arrangement may be such that the filters may readily be changed at occasional service intervals.For example, where the system is fitted to a vehicle powered by an internal combustion engine the arrangement may be such that the filters may be easily changed by the vehicle owner or user, or can easily be changed by a garage, at normal vehicle service intervals, the used filters being disposed of in the normal way.

Alternatively the filters may be capable of being easily cleaned and re-used, for example by the vehicle owner or by a garage.

It will be appreciated that the cooling stage and scrubbing stage may be combined, for example in a stage where the exhaust gases are simultaneously cooled and cleaned by passing through water.

By designing the several stages of the system of the invention with sufficiently large flow cross-sections, and by employing expansion chambers and venturis at appropriate locations it is possible to prevent the system from contributing significantly to the back-pressure at the exhaust manifolds of the internal combustion engine, making it unnecessary to provide any form of positive extraction device such as a fan or impeller to assist removal of the exhaust gases.

It is contemplated that the apparatus of the invention might be produced initially in the form of a kit capable of being fitted easily and inexpensively to existing motor vehicles. Such apparatus may, of course, equally be fitted as a standard production feature during manufacture of motor vehicles.

Claims

1. A means for removing pollutants from internal combustion engine exhaust gas emissions comprising cooling means for cooling the exhaust gases and filter means for subsequently filtering the cooled exhaust gases all without producing substantial back pressure.

2. Means for removing pollutants from internal combustion engine exhaust gas emissions, substantially as hereinbefore described.

3. Any novel feature or combination of features described herein.