Experimental determination of the particle dynamics into a rotating tube

This paper reports the procedure for analysing the biomass powder bed characteristics realized in an experimental pyrolysis reactor. The reaction apparatus is made of a quartz tube which can rotate, horizontally or slightly inclined, with different speeds. Depending on the tube inclination and rotation, different motion conditions (regime, hold-up, residence time and advancing rate) are possible; also the particle characteristics (nature, shape and size, humidity) and the flow rate affect the bed behaviour. After taking some pictures of the bed from the discharge side, they can be analysed by means of the geometry rules; this procedure is here described. In this way the bed profile can be obtained, and this information can be used to calculate the parameters of a proper model, already developed. The methodology here presented will be used in the future to find data to be used in the development of a whole pyrolysis process model including also heat exchange, gas fluid dynamics and pyrolysis reaction kinetics.