Fluidization Behavior Of Fine Grade Synthetic Rutile Simulation

Fluidized bed is an important technology used in chemical engineering. Fluidized equipment has many advantages, such as more higher efficiency on heat and mass transfer process, better bed temperature distribution, easier for controlling and large-scale. But its hydrodynamics are extraodinary complicated because of the intensity non-linear and coupling between gas phase and solid phase. We still have a lot of dark in the fluidized bed law, and have to explore.In this paper, Eulerian-Eulerian Model is used to research the hydrodynamic behavior of fine artificial rutile particle with a density of 4000 kg/m3 and a diameter of 46μm in several different superficial gas velocity. Simulation is carried out in a two-dimensional fluidized bed with 20 mm in width and 80 mm in height. At the superficial gas velocity of 0.004m/s, it acts as a homogeneous fluidization. When the velocity is 0.005m/s, it performances as an aggregative fluidization and some bubbles turn up with some particles. While the superficial gas velocity is improved to 0.02m/s, the porosity increase. This simulations prove the Eulerian-Eulerian model is credible.Within 1 m/s and 40 m/s, researching characters of single jet with two different apertures and gas velocity indicates that initial bubble equivalent diameter, bubble velocity and jet depth increase when aperture and operating velocity augment. On the contrary, initial bubble frequency have a few decreasing. Only when the still bed height very small, it would affect jet forms.Simulations of the double jet system show that it could be classified into three categories:isolated jets, transitional jets, and interacting jets. With gas velocity rising and aperture distance decreasing, jet interacting aggravating. If its trailing vortex have enough appeal, jet will merge. Three and four jets simulations show that lots of bubbles will appear on the apertures around, with low gas velocity and high gas velocity can obtain a well turbulent flow effect. If the jets velocity unequal, the high velocity jet will pull the low velocity because of differ in appeal.According to the characters of fine artificial rutile, perforated rate of distributors are calculated with stability press drop method which is validated by simulations. It can propound some suggestion that we should adopt high press drop distributor, the velocity of gas pass the distributor is depend on superficial velocity and perforated rate, velocity of gas pass the distributor is equal when the apertures is equal in size, and the distributor which central zone has a low perforated rate but high in marginal area can eliminate wall effect.