Abstract: A quadrangular type multi-tube once-through boiler having an arrangement in which a feed path combuation air, combuation chamber, and an exhaust gas channel passing through a flue are alined in substantially the same plane, and provided with a burner duct (5) and a blower (4) each installed in any desired regions in lateral wall portions (s.sub.1, s.sub.2, s.sub.3 and s.sub.4) defining the width of the boiler body (1). The boiler body (1) comprises an assembly (A) of a plurality of substantially vertically disposed water tubes (10), so that combuation gas flows crosswise of the water tubes (10). A burner (3) is disposed in close adjacency to the first row (1.sub.1) of water tubes the water tube assembly (A), whereby even if fuel from the burner is ignited in a space between the first row (1.sub.1) of water tubes and the burner (3), actual combuation does not proceed to completion therebetween but the most of the unburnt gas burns completely while it flows through water tube clearances.

Abstract: A quadrangular type multi-tube once-through boiler having an arrangement in which a feed path combuation air, combuation chamber, and an exhaust gas channel passing through a flue are aligned in substantially the same plane, and provided with a burner duct (5) and a blower (4) each installed in any desired regions in lateral wall portions (S.sub.1, S.sub.2, S.sub.3 and S.sub.4) defining the width of the boiler body (1). The boiler body (1) comprises an assembly (A) of a plurality of substantially vertically disposed water tubes (10), so that combuation gas flows crosswise of the water tubes (10). A burner (3) is disposed in close adjacency to the first row (l.sub.1 of water tubes the water tube assembly (A), whereby even if fuel from the burner is ignited in a space between the first row (l.sub.1) of water tubes and the burner (3), actual combuation does not proceed to completion therebetween but the most of the unburnt gas burns completely while it flows through water tube clearances.

Abstract: A cyclone combustion apparatus includes a combustion chamber having a substantially cylindrical wall, a substantially cylindrical exit throat at the rear end of the combustion chamber, means for supplying fuel into the combustion chamber at a front end thereof, means for supplying air into the combustion chamber and for forming a cyclonic flow pattern of hot gases for combustion within the chamber, and heat exchange means surrounding and extending throughout the axial length of the combustion chamber. The means for supplying air includes a plenum chamber having an air inlet and an annular air supply opening in communication with and coaxial with the combustion chamber. The annular air supply opening has spaced radial vanes tilted at a selected angle from the axis of the combustion chamber. The means for supplying fuel includes a fuel plenum chamber having a fuel inlet and a plurality of radially spaced fuel holes for supplying fuel in the annular air supply opening between the spaced radial vanes.

Abstract: A cyclone combustion apparatus includes a combustion chamber having a substantially cylindrical wall, a substantially cylindrical exit throat at the rear end of the combustion chamber, means for supplying partially preburned fuel into the combustion chamber at a front end thereof, means for supplying secondary air into the combustion chamber and for forming a cyclonic flow pattern of hot gases for combustion within the chamber, and heat exchange means surrounding and extending throughout the axial length of the combustion chamber. The apparatus may also include a substantially cylindrical cooling chamber extending beyond the exit throat from the rear end of the combustion chamber and substantially longitudinally aligned with the combustion chamber. The combustion chamber, the exit throat and the annular secondary air supply opening are dimensioned and configured to effect a cyclonic flow pattern in the combustion chamber.

Abstract: A firetube is mounted in a body of liquid to transmit heat to the liquid. A burner of fluid fuel is attached to one end of the firetube to discharge products of combustion into the firetube. The cooled products are discharged from the other end. The last portion of the firetube in the liquid bath has a series of tubes mounted through its walls. Liquid of the bath passes through the tubes and is heated by the products of combustion in contact with the tubes from within the firetube.