Authors: K. Adham, C. Lee
Canadian Metallurgical Quarterly; Volume: 43; No.1;January 2004; Pages: 67-74
Abstract
Fluidized systems (fluid beds and flash tubes) are gaining new applications in preheating the feed into energy efficient electric furnaces. The main incentive is to lower the electrical energy consumption in the furnace and replace it with less expensive fuel combustion. Additional advantages of preheating to the furnace operation can be pre-calcination or pre-reduction of the furnace charge. A number of options are available for charge preheating such as rotary kilns, shaft furnaces and fluidized preheaters (FP). The main advantages of FP over the other options are the ability to process fine ore, a compact design for installation above the furnace, relatively low capital cost and high energy efficiency. Three key FP systems are investigated and modelled: flash tube (FT), fluidized bed (FB), and multi-stage fluid bed (MSFB). The key physical aspects of each system are identified and incorporated into a process simulation software in order to benchmark its main operating features and its overall energy efficiency. In addition to energy efficiency considerations, it is shown where each FP process is more advantageous than the others depending on the physical and chemical characteristics of the furnace charge.
