Analytical Treatment on the Reaction Zone of Cement Shaft Kiln, Particulary with Consideration of CO Loss Effect

Abstract

An analytical treatment from the view-point of chemical engineering was made on the reaction zone in the shaft kiln which has been operated almost empirically because of the existence of too many relating factors.
As an example, cement shaft kiln was discussed in this paper with particular attention to the effect of CO loss in the excit gas.
With the use of the available kinetic data on combustion and calcination, and the simplified mathematical model as shown in Eq. (1)-(20), the distribution profiles of temperature and chemical conversion degree of the substance concerned in the direction of kiln axis were calculated numerically using a digital computer.
The rather complex interrelationship of the operating parameters was clarified, taking the effect of CO loss in the exicit gas into consideration, which is a very important factor for the heat consumption of the kiln.
Calculated data were compared with the experimental data obtained by pilot plant (300φ×1500mm), and a corrected factor λ for the effective heat transfer coeff cient was introduced and used in further calculations.
It was found through this study that the influence of operating parameters on the distribution profiles of temperature and chemical conversion degree can be well evaluated quantitatively.