20.500.12556/RUL-119801 Convective drying of sewage sludge layer in through-flow Konvektivno sušenje plasti odpadnega blata s tokom skozi plast Drying of the sewage sludge layer was investigated in a convective laboratory dryer at air temperatures of 65 °C and 80 °C and air speeds of 0.53 m/s and 0.83 m/s. The sludge layer was formed by loading cylindrical extrudates on a grate of 0.5 m x 0.5 m size. The drying air was directed through the layer, as typically encountered in industrial belt dryers. Under such setup, the sludge layer structure and porosity significantly affect the air flow conditions and thus the drying rates. Shrinkage and cracking of the material during drying caused changes in the layer's porous structure, that affected the pressure drop and the drag force due to passing of air through the layer. The decreasing of drag force over time was modeled by a simple function that showed excellent agreement to the selected measured data. The sludge layer drying kinetics was determined by fitting the measured data to the most common drying models. Two models, the modified Nadhari and the Wang Singh model, were determined as most suitable for modeling of drying curves. The total drying time per kilogram of sludge was modeled as a function of drying air temperature, drying air velocity and initial sludge dry matter content. The coefficient of determination (R2) of the model is 0.944. Total drying times between 43 minutes per kilogram and 76 minutes per kilogram of sludge were obtained for the investigated range of drying air conditions. wastewater sludge thin-layer drying porous layer drying kinetics drag force odpadno blato s čistilnih naprav sušenje v tanki plasti porozna plast sušilna kinetika sila upora modeliranje true false true Angleški jezik Slovenski jezik Članek v reviji 2020-09-11 10:48:12 2020-09-11 10:48:17 2022-08-31 03:54:48 0000-00-00 00:00:00 2020 0 Ljubljana 0 Str. 481-493 no. 9 Vol. 66 Sep. 2020 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 66.047.41(045) 0039-2480 10.5545/sv-jme.2020.6717 27998723 762116 RAZ_Lipolt_Andraz_2020.pdf RAZ_Lipolt_Andraz_2020.pdf 1 75E3B8F57C2E57D19405A003B5F47175 f85945d01c21c9e89452b4b3103226f1e45d7ddee53313ed161aa40c3f94a840 ece92137-a1b9-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=134538 https://www.sv-jme.eu/sl/article/convective-drying-of-sewage-sludge-layer-in-through-flow/ 1 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=134536 Fakulteta za strojništvo Strojniški vestnik 0 0 0