Development of a new type of thermogravimetric analyser with a mini-tapered fluidized bed. Effect of fluidization of particles on the stability of the system

A new type of thermogravimetric analyser (tapered fluidized bed thermal gravimetric (TFBTG) analyser) has been developed, consisting of a balance, tapered fluidized bed and separate gas nozzle. The relations between the gas velocity and pressure drop and between the gas velocity and weight change were studied experimentally. The effect of the fluidization of the particles on the balance is discussed on the basis of a cold model experimental system. The following results were obtained: (1) there are five regions in the experimental system, i.e. (a) fixed bed, (b) fluidized con region with outward fixed bed, (c) fluidized con region with outward moving bed, (d) complete fluidized bed and (e) fluidized bed with emergent particles; (2) regions (c) and (d) can be used for thermal gravimetry, since the particles fluidize very well and both the pressure drop and weight change are almost constant in these regions. (C) 1997 Published by Elsevier Science S.A.