Heat Transfer Characteristics in Liquid-Solid Circulating Fluidized Beds

• Published in: Nihon Kikai Gakkai rombunshuu. B hen Vol. 73; no. 732; pp. 1704 - 1709
• Main Authors: HASHIZUME, Kenichi, KIMURA, Yoichi
• Format: Journal Article
• Language: Japanese; English
• Published: The Japan Society of Mechanical Engineers 2007
• Subjects: Fluidized Bed; Heat Transfer; Liquid-Solid Two-Phase Flow
• ISSN: 0387-5016; 1884-8346
• DOI: 10.1299/kikaib.73.1704

An experiment was conducted to obtain heat transfer data in liquid-solid circulating fluidized beds. In the experiment, 2 kinds of riser tube having a diameter of 24mm and 12mm were used. Tested particles were of glass and ceramics, and their diameter range was from 2.10 to 4.95mm. Water at ambient conditions was used as the fluidizing fluid. The experimental data showed that the heat transfer coefficient increases gradually with increasing liquid velocity (heat transfer enhanced region), and approaches to the liquid single-phase value. Heat transfer coefficient in the heat transfer enhanced region was found to be a function of the slip verocity between the liquid and the particles. Based on the experimental data, a correlation was proposed to predict the heat transfer coefficient of a liquid-solid circulating fluidized bed, which could reproduce the experimental data with an accuracy of 15%. Comparisons of existing data with the proposed correlation showed also good agreements.