Pulverized coal combustion fly ash penetration through the laboratory scale electrostatic precipitators

Laboratory scale set-up including a laminar flow combustion reactor and laboratory scale electrostatic precipitator (LESP), has been constructed to study the effect of coal properties, combustion conditions and ESP operating parameters on fly ash penetration. LESP design was based on the experience achieved in the real scale ESP studies at 300 MW power plant (Ylatalo et al. 1993). Laminar flow reactor as combustion aerosol generator is operated in flow range 60 to 100 lpm to burn pulverised coal particles. The flue gases are cooled and fed into the LESP. In order to avoid corner effects, electric field inhomogenities as well as to keep the flow velocity in industrial range from 0.5 to 1.5 m/s the LESP was designed with tubular geometry and the experiments are carried out in several temperatures between 20-150 C. Fly ash penetration results will be presented as well as size distributions before and after the LESP in the size range 0.01-1=B5m as determined by differential mobility analyser (DMA) and condensation nucleus counter (CNC). We shall present VI-curve results and sub micron number size distributions at the inlet and outlet of the LESP as well as the collection efficiency in several temperatures and electrohydrodynamic numbers for onemore » coal ashes in comparison with the design and laboratory measurements. The penetration of submicron fly ash particles will be studied as the function of the LESP operation conditions.« less