WO2000023693A1

WO2000023693A1 - A device at combustion engines and the like

Info

Publication number: WO2000023693A1
Application number: PCT/SE1999/001780
Authority: WO
Inventors: Svein ELFSTRÖM
Original assignee: Elfstroem Svein
Priority date: 1998-10-05
Filing date: 1999-10-05
Publication date: 2000-04-27
Also published as: AU1195400A; SE9803404D0; SE9803404L

Abstract

Method and device for cleaning exhaust gases comprising i.e. volatile fuel rests, particles of soot and carbonized coal, oil mist etc. emitted from combustion engines with crankcase ventilation. The invention is characterised in, that the exhaust gases from the crankcase ventilation is led to a condenser (13), where existing oil and possible water are cooled down to condensation temperature, that the condensed oil and water are separated from each other, that the condensed oil is recycled to the crankcase, and that the exhaust gases and the condensed water are brought to the air filter (12) of the engine, where the solid particles are sorted out and the volatile fuel rests are recycled to the engine.

Description

Title

A DEVICE AT COMBUSTION ENGINES AND THE LIKE

The present invention refers to a method for cleaning exhaust gases comprising i.e. volatile fuel rests, particles of soot and carbonized coal, oil mist etc emitted from combustion engines with crankcase ventilation.

BACKGROUND OF THE INVENTION AND THE PROBLEM

Combustion engines have a cylinder leakage during combustion, at which a flow and oveφressure arise in the engine crankcase. When heating/starting the engine, condensation water and precipitation appear at its internal cold surfaces.

For this reason, a built in crankcase ventilation is always provided, however not in two-stroke engines with compression in the crankcase. Furthermore, oil mist is formed when the engine gets warm, and also volatile oil rests from the engine splash lubrication and cooling of the crankshaft, piston and connecting rods. Normal combustion leakage is about 10 %, which then comprises exhaust gases, fuel rests, particles of soot and carbonized coal.

During the last few years, with greater environmental and exhaust gases demands, whishes and laws have been introduced by authorities around the world, to get the motor manufacturers to again close the crankcase ventilation. Simple and often defective constructions have been done in the matter, specially in petrol engines. Unfortunately, most of this constructions comprise in direct combustion of previous mentioned oil rests/mist (HC), fuel, water, and other exhaust gases. This often result in unsatisfactory exhaust gas values, with dangerous HC exhausts.

However, diesel engines can get serious troubles, if the crankcase ventilation is brought direct back to the combustion, as the engine may "gas" itself by the return of volatile rests of fuel or oil. Practically, all light and heavy diesel engines with crankcase ventilation blow the crankcase air right out in the atmosphere. New engines, both petrol and diesel, have less exhausts (ventilation), but these increase for every hour of wear the engine is running. An old worn turbo motor has a combustion leakage up to 20%, with substances (HC) which are directly dangerous (strongly cancer- and mutation-inducing) to human. In old worn engines, one can often recognise these exhaust gases by their strongly irritating smell, and smarting pain in eyes and nose.

THE OBJECT OFTHE INVENTION AND THE SOLUTION OFTHE PROBLEM

The object of the invention is to provide a device at combustion engines which considerably reduces the environmental burden, specially exhausts of hydrocarbons and exhausts of soot and carbonized coal particles. Another object is to separate oil, water, fuel and particles of soot/carbonized coal from each other, and to return clean oil to the engine, and to recycle the exhaust gases (CO, CO₂, NO etc.) to a new combustion, to obtain a clear NO reduction.

These problems have been solved by the characteristics stated in the claims.

DESCRIPTION OF THE DRAWINGS

In the followin^g the invention will be further described in an embodiment with reference to attached drawings.

Fig. 1 shows a longitudinal section along the device according to the invention and Fig. 2 shows a section along line II-II in Fig. 1.

DESCRIPTION OF AN EMBODIMENT The device according to the invention comprises a housing 10, in which an air cleaner 1 1 is provided, comprising an air filter 12, which is surrounded by a helical formed tube 13, which forms a condenser. The inlet 14 of the tube 13 is connected to the crankcase (not shown) of the engine. The opposite end 15 of the tube 13 discharge into an air chamber 16, which surrounds the helical formed tube 13 and which outwards is defined by the housing 10. The longitudinal axis of the helical formed tube 13 is arranged substantially horizontal and in the lowe part of the tube winding, holes 17 are provided, which communicate with a collecting tube 18. This i connected to the crankcase by a not shown lead. The condenser 13 is fixed in the air cleaner by mean of a perforated inner wall 19. Suitably, the air filter 12 consists of a material with good heat insulatin characteristics, i. e. metal shavings, which can transmit the lower temperature of the percolatin combustion air to the condenser coils 13.

The device is also provided with security details, such as a presure compensating device 20 between the colleting tube 18 and the upper part of the tube 13, where a thermostat-controlled relief valve 21 is also arranged. The device 11 is connected either directly to the inlet tube of the engine or to a turbo charger 22.

Principially, the object of the invention is to cool down the oil mist in the exhaust gases from the crankcase over the condenser 13, which surrounds the air filter 12. The oil mist has a normal temperature of 70-120 °C and is, at that time, volatile. The stainless tube 13 is cooled down to atmosphere temperature by means of the high speed of the intake air. This results in condensation o oil and water to liquid. Beacause of the higher viscosity and composition of the oil, a certain adherence is obtained on the inside of the tube, while the water is more mobile and therefore follows the air flow, so that an effective separation of these two components is obtained. The condensed oil runs and is blown to the bottom of the tube windings and is leaving the windings through the holes 17 to the collecting tube 18, from where the oil is returned (recycled) direct to the oil system of the engine.

Condensed water (pearls) does not adhere to the inside of the tube 13, because of the oil film, and is blown further out of the tube together with the volatile fuel rests, soot and carbonized coal particles, to then be let out to the circumference of the air filter, which catches the particles. The volatile fuel rests and the exhaust gases are recycled to the "combustion".

Suitably, the air filter may be a cleanable and recyclable filter, which is not sensitive to volatile compounds. This type of air filter is fast making its way towards the motor bransch, thus mostly because of its ability to contribute to an increase of the effect. The device can also be provided with one or several thermovalves (different lengths) which eliminates plugs of ice during extremely cold conditions.

Furthermore, one important function of the helicalformed condenser is that the liquid part of the mist is extracted against the inner wall of the tube, depending on its speed and rotation, which facilitates the separation.

The device must be adapted to respective engine and mounting, and furthermore, it can also be built into a sound absorptive cover. From the invention, where carbonized coal and soot particles are catched by the air filter of the engine, it follows that these must be cleaned somewhat more often and regularly.

Claims

1. Method of cleaning exhaust gases comprising i.e. volatile fuel rests, particles of soot and carboniz coal, oil mist etc emitted from combustion engines with crankcase ventilation, characterised in, that the exhaust gases from the crankcase ventilation is led to a condenser, where existing oil an possible water are cooled down to condensation temperature, that the condensed oil and water are separated from each other, that the condensed oil is recycled to the crankcase, and that the exhaust gases and the condensed water are brought to the air filter of the engine, where t solid particles are sorted out and the volatile fuel rests are recycled to the engine.

2. Device for cleaning exhaust gases comprising i.e. volatile fuel rests, particles of soot and carboniz coal, oil mist etc emitted from combustion engines with crankcase ventilation, characterised in, that the crankcase of the engine is connected to a condenser, which is provided to cool dow combustion air flowing to the engine, that the condenser is designed as separator, for separation of oil from water, that the condenser is provided with tap openings for condensed oil, that the condenser in turn is connected to the air filter of the engine for separation of solid particles i the exhaust gases and recycling of volatile fuel rests to the engine.

3. Device according to claim 2, characterised in, that the condenser consists of a helical formed tube with substantially horizontal helical axis, and th the lower parts of the helical formed tube are arranged with openings for taping of condensate, whic is recyclable to the crankcase.

4. Device according to claim 2, characterised in. that the air filter of the air cleaner is in heat insulating contact, surrounded by said screw line forme condenser, which in turn is surrounded by an air chamber, to which the outlet of the screw line forme tube is connected.