METHOD FOR DRAINING A PEAT-BATH SUSPENSION

摘要

For the purpose of recovering and transporting in a non-environ-mentally polluting economical manner the solid substance of a peat bath suspension or of a similar aqueous, homogeneous suspension having a low 2 to 5% solid content principally of organic fibres, the present invention provides a method for draining the said suspension by passing it continuously through a static filtration stage having curved or inclined screens where at least a part of the present free water is separated from the suspension to a resulting water content of 90 to 94% therein; a first mechanical double belt screen pressure stage where the remainder of the free water and some of the combined water which is bound and latent in the fibres is separated from the suspension to a resulting water content of less than 90% merely by the pressure arising from the tension of the belt screens; and a second double belt screen pressure stage where the belt screens pass between pressure rollers and where more of the combined water of the fibres is separated from the material to a water content of 80.%, the filtrate arising in the first stage being first purified and then fed to a sewage system with a solid content of at the most 1 gram per litre of water. The fraction still containing fines, separated during purification, is returned to the process for draining.