Process and apparatus for drying moist material

摘要

A waste water treatment assembly produces sludge (16) which is de-watered and dried on a drying unit (2) which has a sludge drying bed (3) and a dying air blower (4). The air is pre-heated using especially heat drawn from effluent water via a heat exchanger or heat pump (7). Heat is recovered from a settlement basin forming part of the waste water treatment installation. Heat may also be covered from trapped rainwater or a rainwater overflow basin. The pre-heated air is ambient air, the temperature and humidity of which is dependent upon ambient conditions. The drying action is supported by solar radiation. The drying bed is a modular construction perforated sheet metal panel. Drying sludge is advanced along the bed by a mixer/transporter (10). The assembly is also surrounded by a transparent cavity-walled shell. Recovered heat energy is also further employed for space heating of buildings. Also claimed is an outlet pipe for clear treated water which also serves as part of a heat exchanger.