Industrial & Engineering Chemistry Research, Vol.56, No.31, 8995-9005, 2017
Heat Transfer and Fluidization Characteristics of Lignite in a Pulsation-Assisted Fluidized Bed
To address the problem of low drying efficiency increasing lignite dryer size, a pulsation-assisted fluidized bed with horizontal tube bundles was built for investigating the heat transfer in lignite particles with the goal of enhancing the lignite drying rate by introducing a pulsed flow to increase the heat transfer rate. Results showed that the pulsation-assisted flow increased the heat transfer rates by a maximum. of 50-100%. The heat-enhancement effect increased as the gas velocity increased, with 3 and 5 Hz pulsation-assisted flows demonstrating higher heat transfer rates than a 1 Hz flow. Local heat transfer rates showed a maximum. Value at the tube top for lignite. Simulation was concluded to analyze the details of the lignite particles and bubble movements to explain the heat transfer rate enhancement effect.