Gas-solid fluidized bed dry coal separation is a typical method of coal separation. During its process, the stability of bed pressure fluctuations is an important index affecting the separation effect, and the main frequency of its fluctuations can directly reflect the strength of the stability. This article selects Geldart A particles as the dense medium, based on the theory of periodic fluctuations, extends from the perspective of a single particle to the perspective of the entire bed layer, and uses the principle of energy conservation, combined with suitable operating conditions for gas-solid separation fluidized beds, to establish a prediction model for the main frequency of pressure fluctuations before bubbling fluidization. And the error was controlled within ± 0.15, laying a theoretical foundation for the study of flow pattern transformation. It can be seen that the main frequency is mainly concentrated around 1-1.5 Hz, indicating that the use of Geldart A particles can ensure the stability of separation.
 

Gas-solid fluidized bed,Geldart A dense medium,prediction model