Apparatus and a method for dewatering wood chips

A method of dewatering wood material (2), the method comprising:

• passing the wood material (2) through at least a first nip (Ni) formed between a first roll (3) and a second roll (4) such that water in the wood material (2) is pressed out of the wood material (2) when the wood material (2) passes through the first nip (Ni),
• carrying the wood material (2) through the first nip (Ni) on an endless conveyor (5) comprising an endless sheet metal band having a thickness in a range of 0.4 mm to 2.0 mm which is permeable to water through perforations having a diameter in a range of 1.0 mm to 5.0 mm formed in the endless sheet metal band and which forms a single loop around the first roll (3);
• wherein a linear load in kilonewtons (kN) of force per distance in meters (m) of a length of the nip extending in a line parallel to a longitudinal axis of the first roll is applied in the first nip (Ni) which is in the range of 500 kN/m-4000 kN/m,
• wherein the endless conveyor (5) has a speed in a range of 0.6 m/s to 5 m/s, and
• wherein the water that has been pressed out of the wood material is sucked through the perforations formed in the endless conveyor by at least one suction device which is located inside the loop of the endless conveyor and said at least one suction device extends in a direction parallel to the longitudinal axis of the first roll.