Gas extraction apparatus for thermal installations

摘要

Hot gases from a furnace or the like are fed to a core or inner tube that terminates at its downstream end at the upstream end of a larger-diameter mixing tube. A jacket surrounding the inner tube is formed with a plurality of compartments which are of increasing cross-sectional area toward the downstream end of the inner tube. A blower is connected to the upstream ends of the compartments or branches or the jacket and the downstream ends of these compartments are connected to a annular nozzle defined between the outside of the inner tube and the inside of the mixing tube. Thus air in the compartments is heated by the hot gases in the inner tube and expand so as to issue from the nozzle at high speed and entrain the gases in the inner tube in jet-pump fashion.