Bubbles And Dense Phase Mass Transfer In The Fluidized Bed Experiments And Theoretical Studies,

Today, the fluidization technology has been extensively applied in chemical engineering, oil industry, metallurgy and electric power industry in China. With regard to the fluidized technology, one of the most important problems is the phenomenon of bubbles. The research of bubbles plays an important effect in analyzing the heat transfer and mass transfer in a fluidized bed.The installation of experiment is founded based on two-dimensional beds model and three-dimensional beds model in the test. The purpose is to produce a single bubble in a fluidized bed and to get the mass transfer coefficient from bubbles to the dense phase. The paper tells the establishment of a fluidized bed and the installation of bubbles in detail. The mass transfer coefficient between bubble and dense phase has been investigated both experimentally and theoretically. The bubble size, its velocity and the mass transfer coefficient have been measured for FCC catalyst and glass beads of Group A powders. The results show that the bubble velocity is in proportion to bubble size in the power of about 0.27, and the mass transfer coefficient is about proportional to bubble size. From streamline function around a sphere and the mass transfer equation, a theoretical equation for the mass transfer coefficient between bubble and dense phase has been derived by introducing effective molecular mass transfer coefficient in fluidized beds as(two-dimension) and the effective molecular mass transfer coefficient in fluidized beds has been obtained as...