Fuel vapor storage and recovery apparatus

A fuel vapor storage and recovery apparatus including a fuel vapor storage canister, said fuel vapor storage canister comprising;

• first and second vapor storage compartments, said first and second vapor storage compartments filled with an absorbent material to form a vapor storage bed;
• at least one vapor inlet port connected to a fuel tank;
• an atmospheric vent port and a purge port;
• said fuel vapor storage canister defining an air flow path between said at least one vapor inlet port and said atmospheric vent port and between said atmospheric vent port and said purge port;
• said first storage compartment being closer in proximity to the vapor inlet port than said second storage compartment and the first compartment to receive vapor from said fuel tank;
• wherein said first and second vapor storage compartments in flow direction are separated from each other by an air gap diffusion barrier and wherein said first and second vapor storage compartments are arranged in concentric relationship;
• wherein said apparatus further comprises a purge heater which is activated during purging;
• wherein the purge heater is located in a purge heater compartment directly communicating with said purge port;
• and
• wherein the purge heater compartment is at least concentrically surrounded by one of the vapor storage beds in a non-insulated fashion, thus allowing heat radiation into the surrounding vapor storage bed.