Sludge drying in CO2 heat pump dryer / Agnieszka Flaga-Maryańczyk, Jacek Schnotale // W: The 23rd International Conference on Solid Waste Technology and Management : March 30 - April 2, 2008 Philadelphia, ... więcej

Sludge drying in CO2 heat pump dryer / Agnieszka Flaga-Maryańczyk, Jacek Schnotale // W: The 23rd International Conference on Solid Waste Technology and Management : March 30 - April 2, 2008 Philadelphia, PA U.S.A. – Chester, PA : Dept. of Civil Engineering. Widener University, 2008. – (Journal of Solid Waste Technology and Management, ISSN 1088-1697). – Il. – Bibliogr. 12 poz., Abstr.

Thermal drying of sludge significantly enhances the number of possibilities of its further usage. The traditional methods of sludge drying are based on the process of evaporation of water in a temperature ... więcej

Thermal drying of sludge significantly enhances the number of possibilities of its further usage. The traditional methods of sludge drying are based on the process of evaporation of water in a temperature of minimum 100 oC. Consequently a significant amount of energy is required and the process has a high environmental impact. The heat pump drying system is an alternative for the traditional method of sludge drying. It is energy efficient and avoids emissions from the drying installation. Sludge is dried by closed loop circulating air treated in the heat pump. A novelty is applying carbon dioxide (CO2) as a refrigerant. CO2 as a natural working fluid in heat pump systems is increasingly important in view of the HFC (Hydrofluorocarbons) alternatives. Due to the critical parameters of CO2 (Tc = 304,13 K and pc = 7,38 MPa) the process in the CO2 heat pump is the transcritical cycle. It provides the possibility of additional hygienization of the dried product which becomes sanitary safe. The article introduces the idea of CO2 heat pump dryer for sewage sludge drying and presents data from laboratory measurements of sludge drying in controlled temperature and humidity environment.