The influence of operating variables on the residence time distribution for material transport in a continuous rotary drum

Rotary kiln transport processes

“…The bulk concentration is sampled experimentally. We see that analysis of such samples can again lead to D, or to other measures of mixing effectiveness (Abouzied et al, 1974;Hogg et al, 1974;Mu and Permutter, 1980;Rutgers, 1965;Wes et al, 1976).…”

A Model for Residence Time Distribution of Solids in a Rotary Kiln

“…This is because the type of tracer has no signifi cant effect on the mean residence time but has a strong effect on the dimensionless variance of the RTD (Sai et al, 1990). Abouzeid et al (1974) reported that there is no signifi cant effect of the particle size on the mean residence time and dimensionless variance of the RTD. On the other hand, Lebas et al (1995) reported that coal and coke with similar particle size distribution, but with different densities, behaved similarly in the kiln giving the …”

Axial dispersion of solid particles in a continuous rotary kiln

“…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). High temperature RTD measurements were done using radioactive tracers (Costa and Peterman, 1959;Groen et al, 1986).…”

“…High temperature RTD measurements were done using radioactive tracers (Costa and Peterman, 1959;Groen et al, 1986). The measured range of the Pe numbers varies from 10-100 for short mixing drums (Abouzeid et al, 1974;Wes et al, 1976), to lo3 for calcination kilns (Groen et al, 1986;Sai et al, 1990). Figure 2 is a schematic of rotary kiln.…”

“…Previous models described the flow in the kiln by a network of ideal flow systems, the parameters of which are adjusted to fit the experimental RTD data. Fan and Ahn (19611, Rutgers (1965a), Abouzeid et al (1974), Wes and Drinkenburg (19761, Karra and Fuersenau (1977), Hehl et al (1978) and Sai et al (1990) proposed the use of an axial dispersion model with an appropriate Pe number determined by experiments. Rutgers (1965a), Groen et al (1986) and Sai et al (1990) used the n tanks-in-series model to fit experimental RTD curves.…”