Apparatus and a method for dewatering wood chips

An apparatus (1) for dewatering wood material (2), the apparatus (1) comprising a first roll (3) and a second roll (4) that form a first nip (N1) in which water can be pressed out of the wood material (2);

• an endless conveyor (5) which is permeable to water and forms a loop around the first roll (3) and which is arranged to pass through the first nip (N1) such that the endless conveyor (5) can carry wood material (2) through the first nip (N1), which is arranged to press water out of the wood material (2) through the endless conveyor (5) in the nip (N1), characterised in that the endless conveyor (5) is a metal band with a thickness in the range of 0.3 mm-2.5 mm, preferably a thickness in the range of 0.4 mm-2 mm.

A method of dewatering wood material (2) which method comprises passing the wood whips (2) through at least a first nip (N1) 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) pass through the first nip (N1), the wood chips (2) being carried through the first nip (N1) on an endless conveyor (5) which is permeable to water and forms a loop around the first roll (3);

• characterised in that a linear load is applied in the first nip (N1) which is in the range of 500 kN/m-4000 kN/m, in combination with the use of a metal band conveyer (5), wherein preferably the endless conveyor (5) has a speed in the range of 0.3 m/s-10 m/s, preferably a speed in the range of 0.6 m/s-5 m/s.