Activated carbon filter having barrier layer
An activated carbon filter for reducing hydrocarbon emissions, includes a plurality of channels, the channels being suitable for the flow of gases therethrough and at least part of the surface of the channel walls having activated carbon for absorbing and/or adsorbing substances, in particular hydrocarbons; and a filter peripheral wall on the outer periphery of the activated carbon filter; wherein the filter peripheral wall includes a barrier layer, in particular in the form of a coating on the outer surface of the filter peripheral wall, preventing or at least significantly reducing the penetration, in particular the diffusion, of gases and/or substances, in particular hydrocarbon-containing gases, through the filter peripheral wall.
1. An activated carbon filter system as part of a fuel vapor buffer device for reducing hydrocarbon emissions, comprising:
at least one activated carbon filter for reducing hydrocarbon emissions, comprising:
a plurality of channels, wherein the channels are suitable to be flown through by gases, wherein at least part of the surface of channel walls which define said channels has a material for absorbing and/or adsorbing substances; and
a filter peripheral wall on an outer periphery of the activated carbon filter;
wherein the filter peripheral wall comprises a barrier layer, which at least significantly reduces penetration of gases and/or substances through the filter peripheral wall; and
a housing for accommodating the at least one activated carbon filter;
at least one sealing device for tightly closing a gap space between an inner wall of the housing and the filter peripheral wall of the at least one activated carbon filter, so that a penetration of gases and/or substances into the gap space is at least significantly reduced.
2. The activated carbon filter system according to claim 1 ,
wherein the channel walls and the filter peripheral wall include activated carbon; and
wherein the filter peripheral wall comprises a barrier layer in the form of a coating.
3. The activated carbon filter system according to claim 2 , wherein the activated carbon filter has activated carbon over at least a partial area of the coating.
4. The activated carbon filter system according to claim 1 ,
wherein the channel walls and the filter peripheral wall include a carrier material; and
wherein the carrier material of the filter peripheral wall serves as a barrier layer, and the carrier material at least partially has an activated carbon coating.
5. The activated carbon filter system according to claim 4 , wherein only an inner side of the carrier material which at least partially defines the channels has an activated carbon coating.
6. The activated carbon filter system according to claim 4 , wherein the carrier material of the filter peripheral wall has activated carbon on an outer wall of the activated carbon filter at least over a partial area.
7. The activated carbon filter system according to claim 1 ,
wherein the activated carbon filter is substantially cylindrical; and
wherein the channels are aligned in an axial direction of the filter.
8. The activated carbon filter system according to claim 1 , wherein:
said material is activated carbon;
said substances are hydrocarbons; and
said penetration is diffusion; and
said gases and/or substances are hydrocarbon-containing gases.
9. The activated carbon filter system according to claim 4 , wherein the carrier material is one of:
plastic or
ceramic.
10. The activated carbon filter system according to claim 1 , wherein the gases and/or substances are hydrocarbon-containing gases.