Abstract: A screw press in which a screw continuously dewaters a suspension. The screw has a threaded section and a downstream compression section with a variable squeeze, and the screw is powered to forward the suspension. A housing accommodates the threaded section and the compression section with the variable squeeze. The suspension is admitted in dilute form at an intake at one end of the press. At another end of the press, the suspension is delivered in dewatered form downstream of the compression section through an outlet. The housing is in the form of a wire basket permeable to liquids and impermeable to solids, and is axially displaceable back and forth adjacent the unthreaded compression section between a non-operating position and an operating position to vary an effective length of the basket. This effective length is zero in the non-operating position for emptying the press.

Abstract: In a disk-type decker that is employed to drain suspensions and that has axially distributed suspension chambers and filtrate chambers that are separated by rotating screen disks and open into a stationary tub, the filtrate chambers are evacuated to increase the throughput of the decker and improve and accelerate drainage. The filtrate chambers are for this purpose divided by radial and axial transverse partitions into individual filtrate-chamber sections distributed along the circumference and sealed off from one another. When the screen disks and hence the filtrate-chamber sections rotate and the sections enter into flow engagement with filtrate outlets at the bottom of the decker, they are simultaneously evacuated, accelerating drainage through the disks. The results are a higher throughput, a lower material density in the filtrate, and lower specific investment costs at the same throughput or material density in the filtrate.