A baffle arrangement disposed within the exhaust flue of a fuel-burning water heater promotes heat transfer from exhausted combustion by-products to the water storage chamber. The baffle arrangement has an elongate planar base and plural exhaust-directing fins spaced along opposite sides of the base. Each fin is a planar body extending perpendicularly from the base at an acute upward angle from a longitudinal centerline to a respective side of the base. The fins deflect combustion by-products laterally outwardly within the flue to promote heat transfer. The fins are of selected configurations generally increasing in surface area upwardly along the planar base for selectively controlling pressure drop within the exhaust flue. Hanger tabs project outwardly from the upper end of the base to suspend the baffle arrangement within the flue. The planar base, hanger tabs and exhaust-directing fins are formed integrally from a unitary body of sheet metal.

A structure of the heat exchange pipe is provided for conducting heat generated by combustion inside a burner to the outside. The structure of the heat exchange pipe includes a receptacle and an insertion. The insertion is disposed in the receptacle. The insertion includes at least three petals, each of which includes a first circular arc section and a second circular arc section. The first circular arc section extends toward a center of the receptacle and has a first arc angle. The second circular arc section has a second arc angle. The second arc section is arranged between two first circular arc sections of two adjacent ones of the petals. The first and second circular arc sections define a flue. As such, the insertion forms a flue baffle device.

A gaseous fuel-air-flue gas burner is described herein. One device includes a housing having a combustion chamber containing a combustion area in which a combination of fuel, air, and flue gas mix to form a flame, a flame arrester having an outer surface for the flame to form, a supply chamber configured to receive the fuel, air, and flue gas mixture at an inlet and provide the combustion area with the fuel, air, and flue gas mixture at an outlet to produce a flame and a quantity of return flue gas, and a return cavity configured to move return flue gas away from the combustion area and into the inlet of the supply chamber.

An internal combustion burner including a combustion chamber supplied with fuel and with oxidant and at least two combustion devices supplied with oxidant and with fuel. Combining two combustion devices of distinct configurations, which respectively generate two distinct types of flames with a system for cooling the walls of the burner by introducing air along the walls, makes it possible to obtain a burner that supplies a combustion gas temperature of up to 1700 C., while at the same time being easily cooled and occupying very little space so that it can, for example, be housed in an existing installation used in the manufacture of rock wool or glass wool.

A water heater appliance for a recreational vehicle includes a tank and a flue disposed within the tank. The flue forms a U-shape that extends to and from an external side of the tank. A gas supply is in fluid communication with the flue. A burner assembly is disposed at an inlet of the flue. A baffle disposed within the flue. The baffle includes a plurality of restrictors configured to the baffle and the flue, and a flue collar mounted to the flue. The flue collar is configured to secure the baffle to the flue.

A system for reducing internal combustion engine emissions includes an engine, a catalytic converter fluidly connected to a combustion chamber via an exhaust line, a glow plug positioned along the exhaust line between the catalytic converter and the combustion chamber, and a flame accelerator, without a fluid connection to a separate fuel supply. Methods of using the system include igniting a mixture of air and fuel in the exhaust line using the glow plug, producing an amount of heated combustion gas.

A windproof structure for the flue outlet includes a flue passage and an air deflector. The flue passage extends in a preset direction and has, in an extension direction, a first port and a second port that are in communication. The first port is configured to be in communication with the outside, and the second port is configured to be in communication with a flue pipe of the gas water heater. The air deflector is disposed outside the flue passage and located on one side of the first port facing away from the second port. The air deflector is spaced apart from the first port by a preset distance, and an orthogonal projection of the air deflector onto the first port covers the first port.