Abstract: A combustion head for a fluid fuel, particularly a liquid fuel, which is burnt particularly in the presence of a gas having an oxygen concentration substantially less than that of air, comprises, adjacent to the actual burner, a generally cylindrical box containing an inlet aperture designed to create a substantial pressure drop on injecting the oxygen-containing gas into the box, and a disc situated at the outlet of the box and dimensioned to create a second and lower pressure drop. The intense combustion produced in the box heats its walls to a temperature substantially above the final point of the distillation curve for the fuel, so preventing coke deposition.

Abstract: A burner for combustible fluids has a distribution opening adapted to feed a combustion chamber and supplied by a source of a comburant (combustion-sustaining gas such as air or a mixture of air and combustion products), a swirl generator between this source and the opening, an injection nozzle for the combustible fluid extending coaxially through this opening, and a constriction located immediately ahead of the discharge end of the nozzle and adjacent an outwardly diverging passage adapted to generate a toroidal vortex in the region of the end of the nozzle.

Abstract: Formation of nitrogen oxides and/or soot is obviated by mixing recycled combustion gas with incoming comburant supplied to a burner via a distribution opening and controlling the mass flow rate of combustion gas being recycled with respect to the mass flow rate necessary for the gaseous comburant, the mixture being passed to the burner as a turbulent flow in which the ratio between the kinetic momentum flux of the mixture and the product of the radius of the said distribution opening times the axial movement quantity flux of the mixture has a value at least sufficient so that the said turbulent flow produces a recirculation of the said mixture within the combustion chamber in the form of a toroidal vortex.

Abstract: A process and apparatus for mixing two fluids by generating a pressure drop across a pair of surfaces each forming a wall of a mixing chamber and confronting one another while separating a respective source of fluid from the mixing chamber. The surfaces being provided with mutually aligned and opposing apertures thereby accelerating the respective gases through the apertures in opposing jets. The resulting mixture of the fluids is conducted away from the chamber in a direction substantially parallel to the surfaces.

Abstract: A fluid fuel boiler having a combustion chamber having an opening for introducing a combustion supporting gaseous fluid. A burner introduces a liquid fuel into the combustion chamber mixed with the gaseous fluid for combustion thereof. Water-heating flow paths are disposed circumferentially and axially of the combustion chamber. Axial hot gas flow paths deliver hot gases from a downstream portion of the combustion chamber to a plurality of nozzles for diverting some of the hot gases along axially spaced paths in a direction circumferentially of the combustion chamber. These latter hot gas flow paths are immersed in the flow paths of the water to improve heat transfer.BACKGROUND OF THE INVENTIONThis invention relates generally to boilers and more particularly to a new and improved modular boiler.

Abstract: A modular boiler having a cylindrical combustion chamber made of three modules and a module comprising a cover and a module comprising an expansion vessel mounted coaxially on the boiler adjacent the combustion chamber at opposite ends thereof. The cover has a frustro-conical configuration with the inner walls thereof diverging from an opening in the cover toward the interior of the combustion chamber at an angle of between 30.degree. and 110.degree.. The combustion chamber is formed of three castings that define the cylindrical combustion chamber and six axial hot gas flow paths spaced circumferentially from each other and disposed axially of and radially of the combustion chamber. Hot gases from the downstream end of the combustion chamber are recirculated to the upstream end of the combustion chamber to improve the combustion.