Monitoring fluidization dynamics for detection of changes in fluidized bedcomposition and operating conditions

In many industrial applications of gas-solids fluidized beds, it is worthwh ile to have an on-line monitoring method for detecting changes in the hydro dynamics of the bed (due for example to agglomeration) quickly, In this pap er such a method, based on the short-term predictability of fluidized bed p ressure fluctuations, is examined. Its sensitivity is shown by experiments with small step changes in the superficial gas velocity and by experiments with a gradual change in the particle size distribution of the solids in th e bed. Furthermore, it is demonstrated that rite method is well able to ind icate ifa stationary hydrodynamic state has been reached after a change in the particle size distribution (a 'grade change').