Method for operating a device having at least one electrically heatable honeycomb body and device for the catalytic conversion of exhaust gases
View Patent ↗A method is provided for operating a device having at least one electrically heatable honeycomb body through which an exhaust gas can flow. The electrically heatable honeycomb body has at least one current distribution structure to which a plurality of short, successive voltage pulses are initially applied during activation, before a constant heating voltage is applied to the current distribution structure to heat the honeycomb body. A suitable device for the catalytic conversion of exhaust gases in an exhaust system is also provided.
1. A method for operating a device having at least one electrically heatable honeycomb body to be traversed by exhaust gas, the at least one honeycomb body having at least one current distributing structure, the method comprising the following steps:
activating the at least one current distributing structure by initially acting on the at least one current distributing structure with a plurality of short successive voltage pulses; and
then acting on the at least one current distributing structure with a constant heating voltage to heat the at least one honeycomb body.
2. The method according to claim 1 , which further comprises generating three to ten of the voltage pulses before applying the heating voltage.
3. The method according to claim 1 , which further comprises providing the voltage pulses with a duration of 10 to 100 milliseconds.
4. The method according to claim 1 , which further comprises providing the voltage pulses with a voltage level being lower than a voltage level of the constant heating voltage.
5. A method for catalytically converting exhaust gases in an exhaust system, the method comprising the following steps:
providing a device having at least one electrically heatable honeycomb body to be traversed by exhaust gas, the at least one honeycomb body having at least one current distributing structure;
activating the at least one current distributing structure by initially acting on the at least one current distributing structure with a plurality of short successive voltage pulses; and
then acting on the at least one current distributing structure with a constant heating voltage to heat the at least one honeycomb body.
6. A device for the catalytic conversion of exhaust gases in an exhaust system, the device comprising:
a casing tube;
at least one first and one second honeycomb body disposed adjacent one another in said casing tube and configured to be traversed in series by an exhaust gas;
at least said first honeycomb body being electrically heatable, having at least one current distributing structure and being spaced apart from said outer casing tube;
sleeves disposed in said electrically heatable honeycomb body;
support elements disposed in said sleeves, projecting into said honeycomb bodies for mechanically interconnecting said adjacent honeycomb bodies and electrically conductively connected to said second honeycomb body;
electric insulation disposed between said support elements and said sleeves; and
a control unit for said current distributing structures, said control unit configured to initially generate a plurality of short successive voltage pulses upon activation, before acting on said current distributing structure with a constant continuous voltage.
7. The device according to claim 6 , wherein said control unit is configured to generate three to ten voltage pulses.
8. The device according to claim 6 , which further comprises an 18 volt supply for the device.
9. The device according to claim 7 , which further comprises an 18 volt supply for the device.