Conditions and characteristics of the coal-water fuel droplets fragmentation in high-speed airflow

Abstract

The article presents the results of experimental studies of the processes of crushing typical droplets of coal-water fuel in an air flow. Fragmentation modes have been established depending on the concentration (φ) of the solid combustible component in the fuel composition. It has been established that the critical Weber number (We) significantly depends on the concentration of coal in the suspension. In this case, the We(φ) dependence has a significantly nonlinear “hockey stick” type with a threshold value of φ≥50 %. When the concentration of coal in suspension is up to 50 % (by weight), the characteristics and fragmentation conditions (floating speed) of the drops are practically no different from the similar characteristics of the process of fragmentation water drops. At φ≥50 %, the values of critical Weber numbers for CWF droplets increase significantly. The influence of the type of coal on the characteristics and conditions of fragmentation droplets of coal-water fuel was also analyzed. It has been established that an increase in the degree of coal metamorphism leads to an improvement in the process of fragmentation a drop of coal-water fuel.