Aerodynamic separation of fly ashes of selective sampling from pulverized combustion of coals of different ranks

This paper reports on the results of the investigation of fly ashes from pulverized combustion of coals of two ranks, i.e., the B2 (sub C) rank, which is taken from Fields 1−4 of the electrostatic precipitators at the BSDPS -1 (the Bfa series), and the T (sa) rank, which is taken from Fields 1 and 2 of the electrostatic precipitators at the MPP-22 (the Mfa series). It has been shown that fly ashes of the Bfa series have a lower bulk density and a higher dispersity and a unimodal particle size distribution. The size of particles increases along the gas-and-dust flow, in particular from the Field 1 to the Field 2 of the electrostatic precipitators. Fly ashes of the Mfa series are characterized by a higher density, a substantially lower dispersity, a bimodal particle size distribution and have rather close size characteristics for ashes from the Fields 1 and 2 of the electrostatic precipitators. The use of the aerodynamic separation has made it possible to obtain three products from fly ashes of both series which differ significantly in the bulk density and size of particles. Combination of selective sampling and aerodynamic separation of fly ashes from pulverized combustion of coals are promising techniques for manufacturing ash products with a controlled density and dispersity.