| Popis: |
Experimental investigation on fluidization characteristics of biomass alone and sand-biomass mixture has been carried out in a 3D fluidized bed by means of visual observation and pressure fluctuation analysis. The biomass material employed is cotton stalk, and the sands used are of three different sizes. They together make up of three kinds of mixtures, in which the percentage of biomass particle in each mixture (X w0 are 1.79, 4.36, 8.36, 15.43 and 31.33 by weight. Additionally, the experiment is conducted over a wide range of gas velocity. It is found that regardless of gas velocities, the biomass alone can not archive good fluidization, whereas small additive of sand substantially improves the fluidization quality. The results also show that the fluidization regime is more sensitive to X w0 as compared with sand particle size. The transition velocity (U c) from bubbling to turbulent fluidization regime decreases with X w0 for the same mixture, while increasing the size of sand component leads to a delay transition in different mixture. |
