Title

Pulsation-assisted fluidized bed for the fluidization of high moisture and irregular particles and its application for brown coal fluidization

Conference Dates

May 22-27, 2016

Abstract

High moisture content and irregular particle is difficult to be fluidized. This is due to the existence of large particles which would affect the fluidization performance. Also, a high moisture content would induce channeling during the fluidization. Pulsation-assisted fluidized bed (PAFB) with the combination of pulsed and steady flow as the fluidized gas was found to be able for the wet biomass particles fluidization [1]. In this study, fluidization performance of high moisture content particle with wide size distribution was investigated in both PAFB and steady fluidized bed.

As shown in Fig. 1, oscillation was more serious and large bubbles were found in PAFB. The bubble size could be controlled in PAFB by adjusting the pulsed flow frequency. Results showed that compared with a steady-flow fluidized bed, pulsation-assisted flow (1~6 Hz) could increase the mass ratio of large particles at the bottom of the fluidized bed by over 10wt% (Fig. 2). Pulsation-assisted flow could also increase the mixing rate and break the liquid bridge between the solid particles by the large generated bubble. This could cause fluidization period 8 times than that with a steady flow, when high moisture content particles were added into the bed semi-continuously. Fluidization finally stopped due to the increasing bed moisture content (Fig. 3). A predicted model was developed to investigate the bubble size effect on the fluidization performance and compared with the experimental results. The optimal operation condition for the pulsed flow in PAFB was investigated based on the developed model.

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Additional Files
Yuping Liu - 55.pdf (220 kB)

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