Rotary cylinders: Solid transport prediction by dimensional and rheological analysis

Abstract

A semi‐experimental model for predicting the axial transport of the granular bed in a rotating cylinder is proposed. It is based on dimensional analysis and on the determination of an apparent viscosity characterizing the flow behaviour of the bed. Unknown constants in the model are determined either by analysis or by tuning with experimental data. An example of such tuning is shown to work well. The model is capable of giving, as a function of filling angle and friction angle, the axial velocity that varies along the cylinder axis. This is important for the control of the process taking place inside the cylinder.

Mixing of granular materials in slowly rotated containers

“…Tumblers are perhaps the most common of solids processing devices; industrial examples include mixers [such as horizontal drum mixers (Carley-Macauly and Donald, 1962); V-blenders (Carley-Macauly and Donald, 1964); and doublecone blenders (Wang and Fan, 197411; rotary furnaces such as coke calcining and alumina calcining kilns (Perron and Bui, 1990;Perron et al, 1992;Bui et al, 19931, as well as a variety of coating operations. A tumbler refers to any hollow vessel which is partially filled with granular material and rotated, so that a circulating flow is produced.…”

Predictive models and operation guidance system for iron ore pellet induration in traveling grate–rotary kiln process

“…Prediction of mean residence time (MRT) in rotary kiln based on particulate trajectory models can be seen in many literatures (Chatterjee et al, 1983;Perron and Bui, 1990;Yan et al, 2002). At the given depth profile, the velocity of the solid materials at any axial position is expressed as Eq.…”

Axial dispersion of solid particles in a continuous rotary kiln

“…Since the axial dispersion is negligible in slipping beds, this work determines axial dispersion only for slumping and rolling flows. Experimental studies of the average residence time in rotating drums (Sullivan et al, 1927;Bayard, 1945;Varentsov and Yufa, 1961;Zablotny, 1965;Chatterjee et al, 1983a,b;Perron and Bui, 1990) yield empirical correlations, valid only for specific materials and operating conditions. Room temperature measurements of the residence time distribution (RTD) in rotating drums were done by tracer techniques, such as counting and weighing of dyed particles (Rutgers, 1965b;Abouzeid et al, 1974;Karra and Fuerstenau, 1977;Sai et al, 1990), or using atomic absorption spectroscopy to measure tracer concentration (Wes et al, 1976;Arlyuk and Shakhov, 1982).…”