In some examples, a gas/air mixing device configured to mix gas and air to provide a gas/air mixture includes a mixer housing with a mounting flange being configured to mount the gas/air mixing device to a fan housing in such a way that a sealing surface of the mounting flange is in contact with a sealing surface of the fan housing. In some examples, the sealing surface of the mounting flange has grooves with a second radius being different from the first radius. In some examples, the sealing surface of the fan housing has a groove, with a second radius being different from the first radius. The mixer housing provides an inlet opening for air, an inlet opening for gas, and an outlet opening for the gas/air mixture. The sealing surface of the mounting flange surrounds the outlet opening of the mixer housing.

A gas furnace according to an embodiment of the present disclosure includes: a mixer for mixing air and a fuel gas, which are introduced through an intake pipe and a manifold, respectively, to form a mixture; a mixing pipe through which the mixture, having passed through the mixer, flows; a burner assembly for producing a combustion gas by burning the mixture having passed through the mixing pipe; a heat exchanger through which the combustion gas flows; an exhaust pipe through which an exhaust gas, as the combustion gas having passed through the heat exchanger, is discharged outside of the gas furnace; and an inducer for inducing a flow of a fluid through the intake pipe, the mixer, the mixing pipe, the burner assembly, the heat exchanger, and the exhaust pipe. In this case, the mixer has a front end connected to the intake pipe, a rear end connected to the mixing pipe, and a side surface connected to the manifold.

In some examples, a gas/air mixing device configured to mix gas and air to provide a gas/air mixture includes a mixer housing with a mounting flange being configured to mount the gas/air mixing device to a fan housing in such a way that a sealing surface of the mounting flange is in contact with a sealing surface of the fan housing. In some examples, the sealing surface of the mounting flange has grooves with a second radius being different from the first radius. In some examples, the sealing surface of the fan housing has a groove, with a second radius being different from the first radius. The mixer housing provides an inlet opening for air, an inlet opening for gas, and an outlet opening for the gas/air mixture. The sealing surface of the mounting flange surrounds the outlet opening of the mixer housing.

A gas furnace according to an embodiment of the present disclosure includes: a mixer for mixing air and a fuel gas, which are introduced through an intake pipe and a manifold, respectively, to form a mixture; a mixing pipe through which the mixture, having passed through the mixer, flows; a burner assembly for producing a combustion gas by burning the mixture having passed through the mixing pipe; a heat exchanger through which the combustion gas flows; an exhaust pipe through which an exhaust gas, as the combustion gas having passed through the heat exchanger, is discharged outside of the gas furnace; and an inducer for inducing a flow of a fluid through the intake pipe, the mixer, the mixing pipe, the burner assembly, the heat exchanger, and the exhaust pipe. In this case, the mixer has a front end connected to the intake pipe, a rear end connected to the mixing pipe, and a side surface connected to the manifold.

A fuel injector is provided for the radial introduction of a fuel/air mixture to a combustor. The fuel injector includes a frame having interior sides defining an opening for passage of a first fluid; at least one fuel injection body; and a conduit fitting. The at least one fuel injection body is coupled to the frame and positioned within the opening, thereby defining flow paths for the first fluid. The at least one fuel injection body defines a fuel plenum, and a set of fuel injection holes are defined through an outer surface of the at least one fuel injection body. The conduit fitting is coupled to the frame and conveys fuel from a fuel supply line to the fuel plenum. Fuel and the first fluid mix in the flow paths and are delivered through the outlet to the combustor.

A premixing device includes a first and a second venturi in which air flows by rotation of a centrifugal fan, first and second communication openings disposed in the venturis, respectively, for allowing fuel gas supplied from a gas supply passage to flow out, a flap valve capable of opening and closing the second venturi on a side downstream of the second communication opening, and an equalizing valve disposed in the gas supply passage on a side upstream of the first and the second communication openings. The gas supply passage, which connects between an outlet of the equalizing valve and the first and the second communication openings, diverges from the outlet of the equalizing valve to independently form a first gas passage and a first straight path, and a second gas passage and a second straight path for the venturis, respectively.

A combustion system includes a fuel distributor configured to output a fuel, an oxidant source configured to output an oxidant, and a mixing tube defining a mixing volume aligned to receive the fuel and oxidant. The mixing tube is shaped to convey the fuel and the oxidant through the mixing volume at a bulk velocity higher than a flame propagation speed. The combustion system includes a flame holder aligned to receive the mixed fuel and oxidant and to support a combustion reaction of the fuel and the oxidant.

A combustion system includes a fuel distributor configured to output a fuel, an oxidant source configured to output an oxidant, and a mixing tube defining a mixing volume aligned to receive the fuel and oxidant. The mixing tube is shaped to convey the fuel and the oxidant through the mixing volume at a bulk velocity higher than a flame propagation speed. The combustion system includes a flame holder aligned to receive the mixed fuel and oxidant and to support a combustion reaction of the fuel and the oxidant.

A premixing device includes a first and a second venturi in which air flows by rotation of a centrifugal fan, first and second communication openings disposed in the venturis, respectively, for allowing fuel gas supplied from a gas supply passage to flow out, a flap valve capable of opening and closing the second venturi on a side downstream of the second communication opening, and an equalizing valve disposed in the gas supply passage on a side upstream of the first and the second communication openings. The gas supply passage, which connects between an outlet of the equalizing valve and the first and the second communication openings, diverges from the outlet of the equalizing valve to independently form a first gas passage and a first straight path, and a second gas passage and a second straight path for the venturis, respectively.

Disclosed herein are methods and systems for burning gaseous ammonia, including receiving a oxidizer gas into a chamber body such that the oxidizer gas generally flows in direction that extends along a longitudinal axis of the chamber body; introducing gaseous ammonia into the chamber body such that swirl is introduced into the gaseous ammonia; mixing the oxidizer gas and the gaseous ammonia to form a combustion mixture; igniting the combustion mixture; and combusting the combustion mixture for a duration such that the gaseous ammonia is converted to combustion products.