DE9014660U1 - Catalyst for two-stroke engines - Google Patents

Description

Gerd Waschkuttis Kreutzerstr. 69

8500 . Nuremberg 7

17.10.1990

UTILITY MODEL REGISTRATION

I hereby register a catalytic converter for two-stroke engines.

It is known that catalysts coated with platinum and rhodium can drastically reduce the pollutants emitted from engines at an exhaust gas temperature of at least 230° - 250° C.

In the case of Trabant and Wartburg vehicles, which have an extremely high oil mixture in the petrol and low exhaust temperatures, it is very difficult to reduce the pollutants: carbon monoxide (CO) and hydrocarbons (HC) to a minimum.

The EC has set limits for petrol and diesel engines. However, if you equip the two-stroke engine with a catalytic converter, the pollutants are reduced by around 50% when it is warm. However, this still falls far short of the EC limits. Using a catalytic converter increases the exhaust back pressure, which damages the engine and the catalytic converter. The biggest problem with two-stroke engines with a petrol-oil mixture is the cold phase, when most pollutants are emitted.
My invention represents:

In the cold phase, i.e. immediately during the start-up process, an additional burner is installed in the exhaust gas flow in front of the catalyst. This burner is intended to ensure that the exhaust gases are heated up immediately.

In order not to increase the exhaust back pressure, I used a catalyst of size 5.66 x 6 inches and a cell width of 200 cells per 1 square inch.

Tests were carried out in accordance with Annex XXV. Result: The pollutants were reduced to such an extent that they fell below the values of a four-stroke engine with a regulated catalytic converter.
In summary:

When the engine is started, the additional burner starts at the same time and quickly heats the exhaust gases to over 250° C. At this temperature, the catalyst converts the pollutants. The oil that comes out of the engine is burned before and after the catalyst. This is possible if the catalyst is large enough and has a large cell width. I also chose a large pre-chamber in front of the catalyst, in which the petrol-oil mixture that comes out of the exhaust manifold can collect and slowly be gasified and burned. Behind the catalyst there is also a large chamber where any remaining exhaust gases are burned further.

At the same time, the catalyst is coated and serves as a heat exchanger.

The additional burner, also called the starter burner, is designed to ensure that the burner only starts working when the engine and catalytic converter are cold. I therefore attached a heating thermostat to the catalytic converter. The thermostat prevents the starter burner from starting when the engine and catalytic converter are warm.

If the temperature falls below the selected temperature set by the thermostat, the burner starts immediately during the start-up process. The burner is controlled by a timer. You can also start the starter burner beforehand and then let the engine start.

When the starter burner starts before the engine is started, the catalyst is heated up.

The advantage is that the pre-chamber and the catalyst are already heated up. When the engine is then started, the exhaust gases are immediately reduced. The starter burner can also be installed in the exhaust or directly in the pre-chamber of the catalyst. The burner can be operated with all liquid fuels, e.g. gas, petrol, diesel, petroleum, methylated spirits, heating oil, methanol, ethyl alcohol and other flammable liquids.

Figure I shows the catalyst complete with heat exchanger and burner,

Figure II shows

5 the starter burner with check valve in the exhaust pipe.

6 the starter burner in the pre-chamber in front of the catalyst

7 the catalyst

8 the casing for the heat exchanger

9 the nozzle for air injection for the heat exchanger

10 the exit of warm air

11 Exhaust gas inlet

12 Exhaust gas outlet

Figure III shows the burner

13 the spark plug

14 the line for the fuel supply

15 the line for air injection

16 the combustion body

17 the burner jacket for air circulation

18 the burner nozzle

19 the air intake openings with multiple openings

20 Fiberglass mat with knitted fabric

Claims (3)

Protection claims 1. Catalyst with starter burner and heat exchanger, characterized in that a starter burner is connected in the exhaust gas flow or directly before or after the catalyst and is made to burn during the start-up phase or before or after the start. The burner can be operated with gas, petrol, petroleum, methylated spirits, heating oil, methanol, ethyl alcohol and other flammable liquids. The burner is controlled by a time relay. 2. Device according to claim 1, characterized in that the starter burner (Figure III) has an air jacket (No. 17) and is provided with air inlet into the combustion chamber through several openings. 3. Device according to claim 1 and 2, characterized in that in the Trabant and Wartburg vehicles the pre-silencer is replaced by the catalyst with heat exchanger and starter burner.