NOVELTY - In a centrifuge (40) for separating the solid and liquid components of a dispersion containing biological material, comprising a drum (42), rotatable about an axis (R) and having a casing (42b) or base (42a) permeable to liquids but impermeable to solids, a dispersion inlet (44), a solids outlet (45) and a liquid outlet (47), the casing widens at the upper end (in the direction away from the base) and is inclined upwards from the horizontal plane at an angle (gamma) of less than 90degrees.    USE - The centrifuge is typically used in fermentation (e.g. biogas production), clarified sludge treatment and water clarification sectors. The dispersion to be separated is specifically a dispersion broth; and/or a dispersion containing one or more of liquid manure, clarified sludge or dispersed silage, green cuttings or slaughterhouse waste (all claimed).    ADVANTAGE - The widening of the drum increases the cetrifugal force relative to the shear force on the casing, increases the centrifugal force towards the top of the drum, provides a favorable weight distribution and reduces stress on the centrifuge and the forces on the drum and its bearing. Almost complete separation of the solid and liquid components is attained, so that risk of contamination of the solids by harmful components in the liquid is minimized (even in the case of dispersions with a very high liquid content) and disposal of recycling of the solids is inexpensive.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) a plant for treating a dispersion containing biological material, comprising a treatment apparatus in which at least part of the biological material is degraded and a centrifuge as described above for separating the solid and liquid components of the dispersion (21) formed in the degradation process; and    (2) a method for separating the solid and liquid components of a dispersion containing biological material, involving supplying the dispersion continuously or quasi-continuously in portions to the upright or inclined drum of a centrifuge and discharging the dispersion on a continuously ascending casing of the centrifuge.    DESCRIPTION OF DRAWING(S) - The figure shows a centrifuge for separating solids from water.    Dispersion (21)    Centrifuge (40)    Centrifuge container (41)    Drum (42)    Base (42a)    Casing (42b)    Motor (43)    Dispersion inlet (44)    Solids outlet (45)    Stored solids (46)    Liquid outlet (47)    Angle of inclination (gamma)    Rotational axis (R)