Prediction of axial velocity profiles and solids hold‐up in a rotary kiln

Abstract

Axial bed depth profiles were experimentally measured in a rotary kiln containing ilmenite particles under steady state and transient conditions. The variables include feed rate of solids, inclination and rotational speed of the kiln. and dam height. The variation of the axial velocity with kiln axis was estimated. The semi-experimental model proposed by Perron and Bui (1990) was modified to include the effect of the variables of the present study. The mean residence time of solids was estimated from the fractional hold-up and expressed in terms of the process variables. The transients induced by a step change in any of the operating conditions were measured as variation of discharge rate of solids with time.

Solid transport in a pyrolysis pilot-scale rotary kiln: preliminary results—stationary and dynamic results

“…(1). However in spite of this modification, the predictive ability of the Seaman equation is good: the predicted volumetric filling ratios are very close to the experimental ones (results for cases [1][2][3][4][5][6][7][8]. When the grid is rolled inside the kiln, the rolling regime was observed and the comparison between experimental and simulation results stays good.…”

“…Many theoretical and experimental studies carried out in the past deal with the study of the solid motion inside a rotary cylinder, drum or kiln [1][2][3][4][5][6][7][8]. Saeman's model, developed in 1951, is undoubtedly the first attempt for modelling such motion [1]: this mechanistic model is widely used nowadays because of its good predictive ability and its simplicity.…”

“…More recent attempts to improve the description of the solid phase motion exist but the developed models tend to be rather complex to use [5,6]. The majority of the studies conducted are concerned with steady-state studies [1][2][3][4][5][6] and there is little published work dealing with the time dependent axial flow of a granular solid through an inclined rotating cylinder [7,8].…”

Fours rotatifs: Modèle dynamique du mouvement du lit

“…Le modble met it contribution plusieurs rCsultats antdrieurs, disparates et variCs mais complCmentaires. Disparates, car plusieurs auteurs se sont prCoccupCs de la dynamique du lit tout en travaillant sur des matkriaux diffirents comme l'alumine (Tscheng, 1978), le sable (Saeman, 1951;Perron, 1990) ou I'ilmCnite (Sai, 1992). ComplCmentaires, car certains se prtoccupaient d'un aspect du mouvement du lit et d'autres suivaient en s'attaquant A d'autres aspects.…”

Numerical prediction of the mean residence time of solid materials in a pilot-scale rotary kiln

“…Since the experimental determination of the MRT is often time consuming, several models have been developed to predict the bed depth and MRT of the solids in the kiln: e.g. the widely used Saeman's model and several axial transport models [6][7][8][9]. The Saeman's model is based on a mechanism for granular flow through the kiln, based on an average particle motion which is determined by the dynamic angle of repose and by the bulk density of the solid material [10].…”