Patent ID: 8920547

Claim:
An adsorbent canister comprising: a casing defining a first adsorption chamber, a second adsorption chamber, and a diffusion chamber therein, and having on a side wall thereof, a fuel introducing port configured to introduce fuel vapor into the first adsorption chamber and an air communicating port configured to introduce air into the second adsorption chamber, the first adsorption chamber and the second adsorption chamber communicating with each other via the diffusion chamber and each extending in a horizontal direction to allow fuel vapor to flow therein in the horizontal direction, the horizontal direction being perpendicular to a direction of gravitational force, the diffusion chamber having at least one of a first diffusion chamber and a second diffusion chamber configured to allow fuel vapor to flow therein in the horizontal direction, the first diffusion chamber positioned on the first adsorption chamber and extending in the horizontal direction over the entire length of the first adsorption chamber, the second diffusion chamber positioned under the second adsorption chamber and extending in the horizontal direction over the entire length of the second adsorption chamber; and an adsorbent capable of adsorbing the fuel vapor and filled in the first adsorption chamber and the second adsorption chamber, wherein: the first adsorption chamber has a first width in a direction perpendicular to a flow direction of the fuel vapor through the first adsorption chamber; the first diffusion chamber has a second width in a direction perpendicular to a flow direction of the fuel vapor through the first diffusion chamber; the second adsorption chamber has a third width in a direction perpendicular to a flow direction of the fuel vapor through the second adsorption chamber; the second diffusion chamber has a fourth width in a direction perpendicular to a flow direction of the fuel vapor through the second diffusion chamber; the second width is the same as the first width; and the fourth width is the same as the third width.