| 摘要 |
This invention relates to a procedure concerning dewatering of suspensions, in particular, suspensions with a relatively low concentration of organic matter or having a dry solid content of less than 15 %. A distinguishing feature of this invention is that dewatering promoting agents are mixed simultaneously with the suspension as thickening occurs. Examples of materials that increases the concentration of organic matter are among others sawdust, synthetic materials that preferably consist of pulverous polyurethane, ground peat or alternatively ground bark. The weight proportion of the additives amounts to at least 5 weight% and preferably to at least 10 weight-% of the total weight of the organic matter. The simultaneous dewatering and mixing is performed with the aid of known dewatering mechanisms. An example of this is the water extracting screw. After the partial dewatering the material is transferred to a press for further dewatering to solid contents above 45 %. |
