ISSN Online: 2379-1748
ISBN Flash Drive: 978-1-56700-517-2
5-6th Thermal and Fluids Engineering Conference (TFEC)
NOVEL SOLAR DRYER FOR OLIVE MILL WASTEWATER
After the third stage of the olive oil extraction process, Olive mills produce environmentally hazardous wastewater called blackwater. Due to residual oils accumulating at the top layer, the water content cannot evaporate when the blackwater is kept in ponds. Since the contents are biologically active, to prevent accidental or otherwise blackwater discharges into streams and groundwater contamination, recent regulations limit the amount of on-site blackwater storage. Hot air dryers that can be used for drying blackwater burn fossil fuels and olive stones, leading to a high carbon footprint. A novel solar dryer that can effectively dry blackwater using concentrated solar energy is developed within this study. The dryer heats the drying surface to 150-170°C using the hot thermal oil stream coming from a parabolic through collector (PTC) or from a PTC simulator equipment for lab testing. The blackwater is sprayed onto the hot drying surface, shaped to collect the residue at the bottom. Numerical analyses of different flow patterns of thermal oil are done to select an effective channel geometry and flow direction. Experimental testing of four different flow arrangements is also performed to increase the temperature uniformity of the dryer surface. The selected six different brass nozzles are tested at various spray cone angles by changing the spray line pressure. As a result of the experiments and accompanying numerical analyses, the best combination of thermal oil flow arrangement and spray system combination is selected for the prototype solar dryer.