Study Of The Characteristics On G-S Magnetically Stabilized Fluidized Bed Under Elevated Pressure

The magnetically stabilized fluidized bed (MSFB) reactors are widely used in industries. Up to now, it lacks of fundamental data for the design and scale-up of these kinds of reactors under elevated pressure. Therefore, the characteristics of gas-solid mass transfer, heat transfer and hydrodynamics of MSFB under elevated pressure have been studied in this dissertation. In this work, the SRNA-4 catalyst particles with different diameter (130～197μm) were used as solid and the compressed air as gas. The hydrodynamics, Gas-Solid mass transfer and heat transfer have been studied under elevated pressure in a upflow magnetically stabilized bed with diameter of 80 mm.The effects of magnetic field intensity, pressure on minimum fluidization velocity Umf and minimum bubble velocity Umb are studied. The results showed that Umf is independent on pressure and field intensity in our experiment. Umb increases as field intensity and pressure increase. The effects of field intensity, pressure, supervelocity on pressure drop were also studied here.Measurement of electrical metal thermo-foil heater surface temperature is used to study the g-s heat transfer characteristic in g-s co-current magnetically stabilized bed. It concludes that g-s heat transfer coefficient in magnetically stabilized bed is smaller than that of conventional fluidized bed. As pressure increases, the heat transfer coefficient increases whereas it decreases when magnetic field intensity gets higher. Heat transfer coefficient also increases with the pressure under different field intensity and it gets smooth as supervelocity increases. When the field intensity is zero, the heat transfer coefficient under 0.9 MPa is about 11.5% higher than that under 0 MPa.Mass transfer between naphthalene cylinder and bed is studied in elevated pressure. The effect of field intensity, supervelocity, pressure, cylinder location on mass transfer coefficient were studied. We conclude that the increase of field intensity and pressure leads to a lower mass transfer coefficient. Mass transfer increases as supervelocity increases, then gets to smoother and then decreases sharply.