Abstract: The invention consists of a pulse combustor, comprising two spaced apart outer plates, the outer plates having flat outer regions, conical regions inside of the flat regions and central hubs, where the volume between conical regions of the plates defines a combustion chamber. The pulse combustor further comprises a plurality of intermediate plates located between the outer plates, the plurality of intermediate plates being spaced apart to form tailpipe regions therebetween and between the outer plates and adjacent ones of the intermediate plates and a burner coupled to one of the hubs, the burner operative to ignite a fuel/air mixture in the combustion chamber. The outer and intermediate plates have spiral coolant passageways therein for conducting cooling fluid to cool expanding gases traveling between the plates through the tailpipe regions. The invention further consists of a burner assembly for use in a combustion chamber.

Abstract: A boiler having a combustor for combusting an air/gas fuel mixture, the combustor including a heat exchanger which conducts coolant therethrough surrounding the combustion chamber and a fan coupled to an air line provides a flow rate of air in the air line. A gas line is coupled at one end to a source of gas and at another end to the air line so as to produce a mixture of gas and air. Means for measuring a property of the air/gas fuel mixture characteristic of its combustibility are utilized. A valve coupled to said gas line is operative to control a flow rate of gas in response to a control signal from the means for measuring. A temperature sensor takes a temperature measurement of the coolant after passing through the heat exchanger and transmits the temperature measurement to the speed control unit. The speed control unit slows down the speed of the fan when the coolant temperature approaches a preset limit.