Discharge screw arrangement

A discharge arrangement for discharging lignocellulosic material, said discharge arrangement comprising:

• a screw conveyor section comprising an inlet for receiving lignocellulosic material from a treatment reactor;
• an outlet section configured to receive lignocellulosic material from the screw conveyor section;
• a conveyor screw rotatably arranged within the screw conveyor section for transporting the material in a material transport direction from the inlet to the outlet section;
• a material spreader rotatably arranged in the outlet section, which material spreader is rotatable in at least a first rotational direction around a rotational axis extending substantially in the material transport direction the material spreader;
• a drive unit configured to rotate the material spreader around the rotational axis in at least said first rotational direction;
• wherein:
• a first opening and a second opening are arranged peripherally of the material spreader in a side wall of the outlet section, said first and second openings being arranged at a distance from one another along an inner perimeter of the side wall,
• the material spreader is configured to, during rotation of the material spreader in said first rotational direction, transport the lignocellulosic material in the first rotational direction and radially outwards towards the first opening for discharge of the lignocellulosic material from the outlet section,
• the second opening is connected to a steam line connectable to a steam source to provide discharge steam into the outlet section, and
• the material spreader is further rotatable in a second rotational direction being opposite the first rotational direction, and wherein the drive unit is further configured to rotate the material spreader in said second rotational direction, wherein the material spreader is configured to, during rotation of the material spreader in said second rotational direction, transport the lignocellulosic material in the second rotational direction and radially outwards towards the first opening and/or the second opening for discharge of the lignocellulosic material from the outlet section.