In order to enhance the solid-gas contact

a new bubbling fluidized bed with tower reactor is designed. The fuel reactor is divided into several chambers along the bed height direction by internal air distributor with caps. In the period of fluidization

a special phenomenon is caused by slugging

which could be named “gushing”. The forming and disappearing of gushing can be recorded on the basis of image with a digital video camera. By using fast Fourier transform (FFT) and wavelet packet transform methods

the pressure fluctuation signal is analyzed to investigate the characteristics on gushing

including fluidization conditions

dominant frequency and energy mode of gushing. The results showed that gushing fluidization appears under the fluidization number of 3.47 in this reactor. Its cycle period is lasting 1-2 s and dominant frequency is around 0.1-0.5 Hz. Changing of reactor structure

like adding one distributor to reach two chambers

adjusting the aspect ratio of lower chamber to be 3:1 and enlarging the valve opening on caps of distributors

is the better structures for gushing fluidization. Therefore

in order to obtain a satisfactory gushing property in the reactor

the inlet gas velocity and reactor structure must be kept in a suitable condition.