Experimental study on particle circulation characteristics of external circulating fluidized bed evaporator

In order to solve the particle circulation problem of external circulation fluidized bed evaporator, a new particle circulation device was developed, and a cold experiment device was set up for reference to the principle of gassolid circulating fluidized bed U-loop seal valve. The adjustment characteristics of the particle circulation device were studied experimentally. The effects of different flow combinations on pressure drop, particle circulation rate and particle volume fraction of heat exchange tube were investigated when the main flow and any auxiliary flow of the sealing valve were combined. It was found that when the main flow rate is constant, the pressure drop of the heat exchange tube increases with the increase of the auxiliary flow rate, and the pressure drop trend is stable when the main flow and loose flow are combined. The flow rate of particle circulation can be adjusted by adjusting the flow rate of any auxiliary flow alone, and fluidized flow has the strongest ability to regulate the particle circulation rate. The amplitude of the power spectral density of the pressure differential fluctuation signal is related to the particle circulation rate and volume fraction, so the flow state in the pipe can be studied by this method.