6.4.4. Catalytic converter

The catalytic converter has the central ceramic part of a cellular design-3-covered with a carrier layer. On a layer of the carrier there are salts of precious metals operating as converters. The catalytic converter is fixed in the case-1-by means of the insulating basic layer-2-compensating at the same time thermal expansions of the catalytic converter (address the illustration Arrangement of Elements of System of Injection in a compartment of the diesel engine of 2.5 l).

Petrol engines

To reduce harmful emissions by means of the catalytic converter, systems of injection has to dose precisely amount of the injectable fuel necessary for combustion. The lambda probe is in a reception pipe in front of the catalytic converter and is washed by a stream of the fulfilled gases. The lambda probe represents the electronic sensor measuring the content of oxygen in final gases and representing its type of fluctuations of tension. Information from a lambda probe is transferred to the control unit of system of injection. The received value allows to regulate composition of air-petrol mix. On the one hand it is necessary as service conditions constantly change (idling, full gas), on the other hand, as optimum reburning of fuel in the catalytic converter happens only in this case if final gases contain enough fuel.

That in the catalytic converter there was a fuel reburning, it is necessary to have temperature of 300 - 800 °C. For this purpose the bigger content of fuel in mix, than is necessary for pure burning.

The catalytic converter of the petrol engine represents the so-called three-functional device. In adjustable process of transformation oxidation of carbon monoxide (SO) and hydrocarbon (NANOSECOND), and also reduction of concentration of nitrogen oxides (NOx) is carried out.

Security measures for an exception of damages of the catalytic converter

For an exception of damages a lambda probe and the catalytic converter it is necessary to fulfill the following requirements:

Petrol engines

Start of cars with AT towage is impossible.

Petrol and diesel engines