A method and apparatus for providing a general purpose computing platform at a router on a network are disclosed. The upper surface of the rotable disk includes an upper step part and a lower step part connected by a riser part. Consequently, a great attraction force acts on the evaporated fuel adsorbed within the canister. The system further includes a spent storage vessel for receiving and storing spent, and a spent transferring apparatus communicably linked to the spent storage vessel for transferring spent from a user when the user is connected to the transferring apparatus.