Screw housing and plug screw feeder

A material transport arrangement for transporting biomass material in a system for treatment of biomass material, said material transport arrangement comprising:

• a plug screw feeder being a force-fed plug screw feeder and comprising a screw housing, a plug screw and a screw pipe, wherein said plug screw comprises different sections along its length direction whereof a first section is at least partly enclosed by the screw housing and a second section is at least partly enclosed by the screw pipe, and
• a feeding device comprising a force-feeding screw connected to a screw housing inlet provided in one side of the screw housing of the plug screw feeder for feeding material from one side into the screw housing, said screw housing comprising a substantially cylindrical inner compartment,
• wherein the screw housing comprises at least one long anti-rotation bar provided to an inner surface of the screw housing and reaching along at least ¾ of a length of the screw housing, wherein said at least one long anti-rotation bar is provided in a lengthwise section of the inner surface, wherein said lengthwise section is provided along the whole length of the screw housing and does not comprise the screw housing inlet, and
• wherein a closest distance along a circumference of the inner compartment between said at least one long anti-rotation bar and a center of the screw housing inlet is less than ⅖ of the circumference of the inner compartment.