The relative change of drying rate as a function of the cumulative ventilation air drying potential in a thin-layer solar drying facility

9th Edition of the International SOLARIS Conference

Krawczyk, P.^1

Division of Power Machines and Devices, Institute of Heat Engineering, Warsaw University of Technology, Nowowiejska st.25, Warsaw

00-665, Poland^1

关键词: Drying process;    Drying rates;    On currents;    Seasonal cycle;    Sewage sludge drying;    Solar drying;    Thin layers;    Ventilation airs;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/556/1/012055/pdf
DOI  :  10.1088/1757-899X/556/1/012055

来源: IOP

【 摘 要 】

Controlling low-temperature drying facilities which utilise non-prepared air is quite difficult, due to very large variability of ventilation air parameters - both in daily and seasonal cycles. The results of experimental studies of sewage sludge solar drying process in thin-layer solar dryer have been presented. It was found that regardless of weather conditions, the rate of sewage sludge drying is significantly changed during drying process. The results showed that the rate of drying decreases with increasing so called cumulative ventilation air drying potential.Knowledge on current dryin rate provides new possibilities for controlling such systems. Based on the results, operating recommendations for analysed type of dryer have been formulated. Experimental data analysed in the paper was collected in 2012 - 2014 during operation of a test solar drying facility in a sewage treatment plant in Blonie near Warsaw, Poland.