Water Sludge Drying: Modelling of a Solar Thermal Plant for a Solar Vacuum Dryer

Bartali R., BAYER Ö., Pınarlı D., Erdoğan S., Bolognese M., BAKER D. K. , ...More

EuroSun 2020, 01 September 2020 identifier

  • Publication Type: Conference Paper / Full Text
  • Doi Number: 10.18086/eurosun.2020.03.11
  • Keywords: ETC, PTC, solar vacuum dryer, predictive simulation tools, decarbonization, SYSTEMS


The use of dryers that operate at pressures below atmospheric can be a smart technological solution to allow better matching between commercial solar collectors and solar drying applications. At atmospheric pressure, water boils at 100 degrees C, while at 500 mbar, 200 mbar, and 100 mbar water boils at 81.5 degrees C, 60.5 degrees C, and 45.6 degrees C, respectively. For instance, for Evacuated Tube Collectors (ETC) it is challenging to provide a constant heat at temperatures higher than 90 degrees C. Furthermore, the tuning of the boiling temperature allows a better adaptation of the solar heat provided by a solar plant to the heat required for water sludge drying. To understand the technical feasibility of a Vacuum Solar dryer for water sludge, two solar plants with two types of solar collectors with water as the working fluid were modelled: i) ETC ii) parabolic trough collector (PTC). The modelling and design of a vacuum dryer for the drying of water sludges is presented. The results reveal that a light vacuum can improve the performance in terms of the solar fraction of the solar dryer for both ETC and PTC solar fields.