Liquid affects particle circulation in spray gas-solid fluidization by forming different extent of particle agglomerates and directly reduce heat and mass transfer of the reactor. Ethylene glycol solutions of various viscosities were sprayed onto fluidized bed to artificially create agglomerates. The results showed that liquids of different viscosities would form different agglomerates in fluidized bed

which can be divided into four groups by agglomerate size

including microaggregation

nucleation agglomerates

coherence agglomerates

and paste agglomerates. Recursive analysis of differential pressure fluctuation signal in flow process indicated some obvious differences in recursive pattern structure under different agglomeration conditions. Further analysis finding on distribution of recursive feature indices of 50 flow conditions was used to identify agglomeration structures which 96.39% overall recognition rate was achieved. Therefore

agglomerated state in fluidized bed was quickly identified by recursive analysis of differential pressure signal.