Production of Well-Controlled Laminar Aerosol Jets and Their Application for Studying Aerosol Combustion Processes

Generation of steady-state solid aerosol jets with controllable parameters is often necessary in experimental studies and industrial processes.Most of the current approaches use a  uidizedbed to produce an aerosol  owandalways introduce initial turbulence into the jet. Toproduce a laminar aerosol jet,  ow straighteners and long tubes are used that make the design cumbersome and in exible. In addition, in a  uidized bed-type system, the aerosol number density andgas  ow rate are inherently interdependent. Ina new apparatus described in this paper, metal aerosol is produced using an electrostatic recharging of particles in a DC electric Ž eld of a parallel plate capacitor, a so-called electrostatic particulate method. The powder is aerosolized within the capacitor without using any gas  ows and only a small velocity, a laminar gas jet is used to carry the aerosol away from the chamber through a small nozzle made in the top plate of the capacitor. It is shown that the aerosol number density is controlled by an electric Ž eld, independently of the gas  ow rate. The usefulness and  exibility of the new technique for the aerosol combustion studies is demonstrated. Preliminary results on characterization of the produced small-scale, laminar, premixed, lifted aluminum-air  ames are reported. The  ame propagation velocities aremeasured and compared to the earlier results; overall  ame dimensions and radiation proŽ les are determined. Individual particle  ame zones are visualized in the aluminum-air aerosol  ame for the Ž rst time.