摘要 |
An apparatus is disclosed for discharging material through an elongate aperture in a substantially constant amount per unit length of said aperture. The apparatus comprises a screw discharging unit having an inlet end and including a screw housing with a casing wall and a screw rotatably mounted in the screw housing. The elongate aperture is provided in the casing wall and extends substantially parallel to the axis of rotation of said screw. The screw has a core and at least one screw blade extending around the core and having a predetermined pitch for feeding the material from said inlet end to the elongate aperture. The core and said casing wall define therebetween a space having an annular cross section area successively decreasing in the direction of feed of the screw. |