Pulse combustion apparatus

Abstract

The disclosure relates to pulse combustion apparatus generally and to air furnaces of the pulse combustion type. In one aspect, the invention provides a furnace which includes a combustion chamber and an exhaust system disposed in a passageway for air to be heated. The exhaust system includes a primary exhaust pipe, a manifold to which the primary exhaust pipe is coupled, and a plurality of heat exchange pipes which extend from the manifold across the air passageway. The primary exhaust pipe, manifold and heat exchange pipes form a reasonant system with the combustion chamber so that the ignition of successive fuel charges in the chamber causes pressure waves to oscillate throughout said exhaust system including the heat exchange pipes for promoting transfer of heat from the pipes to air flowing through the passageway in use. According to another aspect of the invention there is provided a control system for a pulse combustion apparatus in which the air velocity in a combustion air intake is sensed and used for controlling the apparatus. The system responds to a first air intake velocity as indicating satisfactory operation of a starting blower and activates the gas supply and ignition means, and to a second air intake velocity as indicating establishment of combustion; the circuit will then de-activate the ignition means and blower. The system also includes a timer which will shut off the gas supply if the second velocity is not achieved after a predetermined time interval from initiation of a starting attempt.

Dependencies are inferred from the claim text.