Screw assembly for disintegration of lignocellulosic material

The present invention relates to a screw assembly comprising an elongated screw for transporting lignocellulosic material， the elongated screw comprising a screw core and a screw blade arranged on said core， and an elongated screw housing comprising an end wall at a first end， the end wall having an outlet opening， and the housing further comprising an inlet portion with a material inlet， wherein the screw is arranged in the housing for transporting the lignocellulosic material from the inlet portion to the outlet opening at the first end， the housing being configured to fit around a circumference of the screw， wherein a center of the inlet portion is arranged at a first distance from the first end， the screw blade extending in said inlet portion and further extending a second distance from the center of the inlet portion towards the first end， said second distance being smaller than the first distance.