20.500.12556/RUL-153474 Effects of layer inhomogeneities on the process of sewage sludge convective drying Convective sewage sludge drying is often carried out in belt dryers, where the air flow is directed through the layer. In such a configuration, drying air properties, as well as the structure of the layer and its homogeneity are key factors affecting the drying process. In the present work, these factors were investigated using laboratory experiments on relatively large sludge samples with a mass of several kilograms. Drying was performed at relatively low drying air parameters (time-averaged temperatures of 65 to 80 °C and velocities of 0.44 to 0.78 m/s). The inhomogeneity of the sludge layer drying was observed by measuring the layer surface temperature with an IR camera. The reduction in layer thickness during drying was measured using an optical laser-based method. Analysis of the data included regression and fitting of the data to parametric drying curves, with the modified Nadhari drying law providing the best fit. The standard deviation of the layer surface thermograms (S) was used as a parameter that accounted for the layer homogeneity and consequently drying evenness. Higher values of S corresponded to lower drying rates and consequently longer drying times, highlighting the importance of producing layers with a homogenous structure. The measured layer thickness reduction rate indicated the overall drying intensity almost from the beginning of drying. Both the surface temperature unevenness and the layer height reduction measurement methods were demonstrated as viable approaches for real-time monitoring of the drying process with potential for application in real-scale dryers. wastewater sludge porous layer drying kinetics shrinkage thermography blato čistilnih naprav porozna plast kinetika sušenja krčenje termografija true false true Angleški jezik Slovenski jezik Članek v reviji 2024-01-09 11:58:27 2024-01-09 11:58:35 2024-01-17 03:43:20 0000-00-00 00:00:00 2024 0 0 Str. 34-47 no. 1 Vol. 42 2024 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 628.336.4:66.047 0737-3937 10.1080/07373937.2023.2259974 166496771 Effects_of_layer_inhomogeneities_on_the_process_of_sewage_sludge_convective_drying.pdf Effects_of_layer_inhomogeneities_on_the_process_of_sewage_sludge_convective_drying.pdf 1 BCBB9F56719B756DDE0F8EA20F6F9CFC f40550b92b6fa3551b010f7fd0bb961ea74cd910631dfd6f889d62135be75760 fe686c49-b45e-11ee-9139-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=179645 https://www.tandfonline.com/doi/full/10.1080/07373937.2023.2259974 1 0a70cb28-aede-11ee-8bf0-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=179485 Fakulteta za strojništvo 0 0 0