Effects of liquid feed rate and impeller rotation speed on heat transfer in a mechanically fluidized reactor

作     者：Dhiraj Kankariya Cedric Briens Dominic Pjontek Stefano Tacchino 

作者机构：Department of Chemical and Biochemical Engineering University of Western Ontario London Ontario N6A 5B9 Canada 

出 版 物：《Particuology》 (颗粒学报（英文版）)

年 卷 期：2018年第16卷第4期

页      面：25-32页

核心收录：

学科分类：082903[工学-林产化学加工工程] 0817[工学-化学工程与技术] 08[工学] 0829[工学-林业工程] 0805[工学-材料科学与工程（可授工学、理学学位）] 082701[工学-核能科学与工程] 0827[工学-核科学与技术] 0703[理学-化学] 082201[工学-制浆造纸工程] 0822[工学-轻工技术与工程] 0702[理学-物理学] 

基　　金：the Natural Sciences and Engineering Research Council of Canada (NSERC) for their financial support 

主　　题：Mechanical fluidization Induction heating Impeller rotation Heat transfer Particle size 

摘      要：A mechanically fluidized reactor （MFR） is a novel and compact reactor used for biomass pyrolysis. Endothermic biomass pyrolysis requires heat provided from the wall of the MFR. Meanwhile, mixing with a vertical stirrer helps achieve effective heat transfer from the wall to the bed. Here, the heat trans- fer characteristics between the wall of a 1.0-L MFR and its bed of mechanically fluidized sand particles were studied. An induction heating system was used to heat the wall, while a vertical blade stirrer was used for mixing. Heat transfer measurements were carried out using silica sand particles, having three average Sauter mean diameters： 190, 300, and 600 p.m. The overall wall-to-bed heat transfer coeffi- cients were estimated using temperature measurements taken during continuous injection of water onto the fluidized bed. The overall heat transfer coefficient for bed temperatures of 500-700℃ increased as particle size increased or superficial velocity of the vaporized liquid increased. Effect of impeller rotation speed also was investigated. Typically, the overall heat transfer coefficient increased as rotation speed increased. The wall-to-bed heat transfer coefficients obtained in this study are comparable to estimates from traditional bubbling fluidized beds, even at vapor velocities below the minimum fluidization veloccity.