Patent ID: 7935179

Claim:
A method for exhausting gas from a coating material comprising the steps of: feeding coating material to a bottom area of a drum rotating around an essentially vertical axis inside a vacuum tank, the vacuum tank having an inner wall, the vertical axis defining a radial direction and a height direction defined as extending vertically parallel to the vertical axis, wherein the drum has an inner wall with a plurality of steps, each step defining a level, which step levels ascend in the height direction as the steps progress outwardly in the radial direction; using forces created by rotating motion of the drum to cause the coating material to rise up the inner wall of the drum and flow over at least two of the plurality of steps; veiling the coating material over a front edge of each step to form a radially extending veil-like thin film of the coating material spaced from the inner wall of the drum, which extends between said front edge of the step to the inner wall of the drum; and conducting the coating material out of the tank.