摘要 |
The present invention relates to a plant and a method for producing and treating wood fibres in a plant comprising a fibre-producing part having a chip preheater ( 1 ) and a beater ( 2 ) for freeing fibre from wood chips. Such a plant and such a method are included as parts in a continuous production process of board and the object is to reduce the emission discharges of foremost VOC and formaldehyde, during different parts of the process as well as from the finished product. The method comprises feeding of wood chips (A) into an upper part of the chip preheater ( 1 ), discharge of wood chips in the bottom of the chip preheater to a screw conveyor ( 12 ) for further transportation into the beater ( 2 ), compression of the wood chips in a compression zone ( 15 ) in the screw conveyor, supply of steam (B) into the lower part of the chip preheater for washing fed chips in the counterflow direction, disposal ( 8 ) of flue gases in the form of released organic emissions, steam and air in the upper part of the chip preheater, as well as disposal of flue gases generated during the compression through an outlet ( 13 ) arranged in the compression zone. The plant has the corresponding parts. |