Process and apparatus for determining the dry matter content of a sludge and application to obtain a display and control signal

摘要

In order to provide a process and an apparatus for determining the dry matter content of a sludge and to create an application for controlling sludge dewatering which permit a reliable indirect dry matter content determination in the sludge feed stream in a simple manner, the dry matter content of the feed stream is determined from the volumetric flow rate in the outlet of the dewatering apparatus as a first parameter, the volumetric flow rate in the feed to the dewatering apparatus as a second parameter, the dry matter content in the thickened sludge outlet as a third parameter and the specific gravity of the solid sludge in the thickened sludge outlet according to the relationship <IMAGE> in a computing circuit. In accordance with the apparatus, inductive flow meters are used to measure the volumetric flow rates. A display and control signal is also obtained from this which can be used for the metered feed of flocculants to a sludge to be dewatered, the rate of flocculant addition being changed in accordance with the signal.