Abstract: This disclosure relates to a heat exchanger including a plurality of cylindrical walls that are joined together to form at least one annular chamber. A plurality of tubes spiral through the chamber, each of the tubes forming a coil and the coils being axially separated. A fluid is moved in one direction through the coiled tubes, and simultaneously another fluid is moved through the chamber, thereby producing a transfer of heat between the two fluids. In the instance where the heat exchanger is used as a boiler or steam generator, the fluid in the tubes is water or water vapor, and the fluid in the chamber is hot exhaust gases from a burner mounted at the center of the exchanger.

Abstract: This disclosure relates to an external combustion engine including an engine housing forming at least one pair of opposed cylinders, a piston mounted for reciprocating motion in each cylinder, a rotatable power output shaft mounted between the pistons, and a roller assembly connecting the pistons with the shaft. A boiler and a condenser are connected to supply a pressurized vapor to the cylinders in order to reciprocate the pistons and rotate the shaft. The moving pistons operate as an air pump for moving air through the condenser and the boiler.