低料位操作下气固挡板流化床的压力脉动特性

毕业设计（论文）外文摘要Title Pressure pulsation characteristics of gas-solid bafflefluidized bed under low level operationAbstractBased on the present series of mechanical fluidized bed cold model experimentalapparatus,it is still necessary to convert the crp-1 catalytic cracking catalyst directlyinto the internal solid medium and use ambient air as a fluidizing medium for passingthe gas velocity.The internal components are installed in the operating mode above thebed height in order to analyze the pressure pulsation characteristics within the bed bycontinuously adjusting under the initial load height (H)450 mm operating conditions.The results show that the mean pressure in the single component layer increases withincreasing surface gas velocity in three steps:the average pressure increases slowlywith increasing surface gas velocity;the mean pressure increases rapidly.It is almostunchanged.As the axial height increases,the pressure gradually decreases.As theheight of the bed increases gradually,the pressure pulsation criterion also decreasessharply.In particular,the standard deviation of pressure pulsation at the bottom of thebed shows the standard deviation of the pressure pulsation at the center of the bed,when the standard deviation of the pressure pulsation increases first and then decreasesin the process of increasing the height of the 0.6 m bed,which is hardly changed by theheight of the bed.When the gas velocity is in the range of 0.04M/s Ug =0.44M/s,gas-solid two-phase flow in a single component fluidized bed is at the stage ofTurbulent Fluidization.In the case of 0.44m/s =Ug 0.83M/s,the gas-solid phase inthe fluidized bed is in bubbling bottle transition fluidization,and the pressure ripplepower spectral density curve appears as a single dominant frequency and is much largerthan the density value corresponding to the other frequency density value.When