Patent ID: 8814005

Claim:
A mixing tube for use in a foam assembly wherein the foam assembly has an air chamber, a liquid chamber, a means for pressurizing the air chamber and the liquid chamber, and a porous member, the mixing tube comprising: an elongate mixing channel having an upstream end and a downstream end, the elongate mixing channel having a cross sectional area substantially the same from the upstream end to the downstream end; an exit zone at the downstream end of the elongate mixing channel, the exit zone is a chamfer expanding to a cross sectional area that is larger than the cross sectional area of the elongate mixing channel and continuously increases to a downstream end of the exit zone, and the downstream end of the exit zone being configured to be upstream of the porous member; wherein the elongate mixing channel has a length greater than the exit zone; and wherein the mixing tube is configured such that when positioned in the foam assembly, the upstream end of the elongate mixing channel is in flow communication with the liquid chamber, the elongate mixing channel is in flow communication with the air chamber and air from the air chamber is injected into the mixing channel spaced upstream of the downstream end thereof such that liquid combined with air passes through the substantially the same cross sectional area of the elongate mixing channel and then into the expanding cross sectional area of the exit zone.