The Energy Efficiency of Burners for High-Velocity GAS-Flame Spraying

Y.I. Yevdokimenko, V.M. Kysil, G.A. Frolov

Increase of energy efficiency of burners for high velocity gas-flame (HVGF) spraying is the primary goal of improvement them. A criterion for assessing the energy efficiency HVGFS-burner in the form of a conditional its efficiency is proposed. As criteria of energy efficiency of HVGFS-burner a particles conditional total enthalpy is accepted. Burner energy efficiency determines by the part supplied energy, which was converted into heat and kinetic energy of the dispersed phase. The effectiveness of the nozzle channels of various configurations of existing HVGFS-burners is considered. It is shown that under equal thermal power feeds from subsonic flows are long provide more efficient heating of the particles, and the supersonic – more effective to disperse them, and the energy efficiency of the latter is much smaller. Combined channels, consisting of long cylindrical subsonic and supersonic regions, have energy efficiency nearly equal to that of subsonic channel at a velocity of particles, exceeding attainable supersonic channels. It is shown that the maximum energy efficiency has a gas-dynamic channel with consumption control parameters of the gas flow, which provides maximum temperature and velocity.

Key words: high-velocity flame spraying, burner, energy efficiency, burners gas-dynamic configuration, conditional coefficient of efficiency of burner.