Sludge thickening or dewatering process, uses combination of sludge weight and solids content measurements and disposal and operating cost values to optimize a total cost value

摘要

Sludge input and exit flow measurements relating to weight and dry solids content are carried out and combined with disposal and operating cost factors to give a total cost value which is used to regulate the control parameters in order to reduce this total cost value. A sludge thickening and/or dewatering process comprises the following steps : (b) carrying out measurements to determine the output weight (Moe) representing the weight of the sludge exit flow per unit time ; (c) determining sludge disposal cost (Ks-afz.) by multiplying the output weight value with a pre-determined disposal tariff (fafz) per weight of sludge ; (d) determining a dry solids end value (Vuit) giving the weight of dry solids per unit time for the exit flow of sludge ; (e) determining the dry solids disposal costs (Kds-afz.) by dividing the sludge disposal cost by the dry solids end value ; (f) determining the operating costs (Kbedr.) per dry solids output by adding up at least one fixed operating cost (Kvast) per time unit and/or at least one variable operating cost (Kvar) per time unit depending on process parameters, and then dividing this sum by the dry solids end value ; (g) determining total cost (Ktot) by adding the cost values obtained in steps (e) and (g) ; and (h) regulating control parameters in order to reduce the total cost value obtained in step (g). Independent claims are also included for (a) the process apparatus, (b) a signal processing device for this apparatus, and (c) a data carrier for the signal processing device, provided with computer-readable instructions.