Example apparatus and methods providing for the improved chemical conversion of the combustible components of a gaseous medium are disclosed. In some examples, the apparatus includes a guiding body that guides the flow of the gaseous medium within a reaction chamber of the apparatus. In some examples, the guiding body of the disclosed apparatus is configured to stabilize a residence period of the gaseous medium in the reaction chamber. In some examples, the guiding body results in a flow path of the gaseous medium within the reaction chamber being optimized and/or maximized, and/or results in a short circuit flow of the gaseous medium in the reaction chamber being suppressed. In some disclosed examples, the guiding body causes at least a portion of the flow path of the gaseous medium within the reaction chamber to take the form of a cyclone flow.

An insert for a radiant tube of a furnace including a first section adapted to absorb heat from combustion gases passing through the radiant tube and radiantly transfer the heat to a wall of the radiant tube and a second section for directing heat and gases in the radiant tube toward the first section of the insert and a system including a radiant tube and one or more such inserts. Also, a method of improving heat transfer from a radiant tube of a furnace to the material being heated including supplying an insert as described above and placing the insert into the radiant tube such that the first section corresponds to a portion of the radiant tube that is closest to the material being heated. Also, an insert for a radiant tube of a furnace including a ceramic body and a metal deposited on the surface of the ceramic body.

An insert for a radiant tube of a furnace including a first section adapted to absorb heat from combustion gases passing through the radiant tube and radiantly transfer the heat to a wall of the radiant tube and a second section for directing heat and gases in the radiant tube toward the first section of the insert and a system including a radiant tube and one or more such inserts. Also, a method of improving heat transfer from a radiant tube of a furnace to the material being heated including supplying an insert as described above and placing the insert into the radiant tube such that the first section corresponds to a portion of the radiant tube that is closest to the material being heated. Also, an insert for a radiant tube of a furnace including a ceramic body and a metal deposited on the surface of the ceramic body.

An insert for a radiant tube of a furnace including a first section adapted to absorb heat from combustion gases passing through the radiant tube and radiantly transfer the heat to a wall of the radiant tube and a second section for directing heat and gases in the radiant tube toward the first section of the insert and a system including a radiant tube and one or more such inserts. Also, a method of improving heat transfer from a radiant tube of a furnace to the material being heated including supplying an insert as described above and placing the insert into the radiant tube such that the first section corresponds to a portion of the radiant tube that is closest to the material being heated. Also, an insert for a radiant tube of a furnace including a ceramic body and a metal deposited on the surface of the ceramic body.

An insert for a radiant tube of a furnace including a first section adapted to absorb heat from combustion gases passing through the radiant tube and radiantly transfer the heat to a wall of the radiant tube and a second section for directing heat and gases in the radiant tube toward the first section of the insert and a system including a radiant tube and one or more such inserts. Also, a method of improving heat transfer from a radiant tube of a furnace to the material being heated including supplying an insert as described above and placing the insert into the radiant tube such that the first section corresponds to a portion of the radiant tube that is closest to the material being heated. Also, an insert for a radiant tube of a furnace including a ceramic body and a metal deposited on the surface of the ceramic body.

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 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.