An immersion-type burner heater includes a heater protection tube that is installed so as to penetrate a furnace wall or an upper lid of the molten-metal holding furnace with the tip end thereof being closed; an inner cylindrical member arranged inside the tube so as to define a combustion flow passage S between the tube and itself with the tip end side thereof being open and the inside thereof serving as an exhaust gas flow passage; and a gas burner part supplying fuel gas and air to the combustion flow passage. A helically extending projecting part is provided on at least one of the outer peripheral surface of the member and the inner peripheral surface of the tube at a position that is closer to its tip end side than to the part penetrating the furnace wall or the upper lid.

Methods and devices for gas mixture combustion on a surface of a permeable matrix are provided which produce or result in surface stabilized combustion (SSC) with increasing amounts of radiation energy emitted by the matrix surface and decreasing concentrations of pollutant components in the combustion products. The gas mixture is fed to a burner that includes a permeable matrix material having a first thermal conductivity and configured to preheat the combustible gas mixture as it travels through the matrix. The burner includes a plurality of thermal elements having a thermal conductivity higher than and disposed in thermal transfer communication with the matrix base material. The permeable matrix base material forms a combustion surface with at least a portion of the thermal elements exposed above the combustion surface. The gas mixture is combusted at or near exit pores and channels formed at the permeable matrix material combustion surface.

A burner module that can be used in combusting an air/fluid fuel flow is described. The burner module may be incorporated in an appliance. The burner module comprises a burner face comprising catalytic material for combusting the air/fluid fuel flow and a perforated screen having a plurality of micro-perforations where the perforated screen is positioned upline to the burner face to increase combustion; an integrated gas burner for connection to a pressurised fluid fuel flow where the integrated gas burner comprises a burner module and a gas train. The gas train comprises (a) an ejector for entraining air with the fluid fuel flow; and (b) a diffusor for converting the air/fluid fuel flow kinetic energy into pressure and for performing flow expansion.

The invention provides a burner module for use in combusting an air/fluid fuel flow wherein the burner module comprises a burner face comprising catalytic material for combusting the air/fluid fuel flow and a perforated screen having a plurality of micro-perforations wherein the perforated screen is positioned upline to the burner face to increase combustion; an integrated gas burner for connection to a pressurised fluid fuel flow wherein the integrated gas burner comprises a burner module and a gas train wherein the burner module comprises a burner face comprising catalytic material for combusting the air/fluid fuel flow and a perforated screen having a plurality of micro-perforations wherein the perforated screen is positioned upline to the burner face to increase combustion; and the gas train comprises: (a) an ejector for entraining air with the fluid fuel flow; and (b) a diffusor for converting the air/fluid fuel flow kinetic energy into pressure and for performing flow expansion;
and an appliance comprising the integrated burner.

A thermophotovoltaic (TPV) system, comprises a substrate, an emitter material adhered to the substrate, and a thermophotovoltaic (TPV) cell. The emitter material is a typically a metal oxide doped nickel oxide sol-gel material, in which the metal is magnesium or zirconium, and in which the sol-gel material comprises 97-99 mol % metal oxide, and about 1-3 mol % nickel oxide dopant. Providing an emitter material as a sol-gel allows the material to be coated on to surfaces providing better adherence to the surface, and also provides excellent heat stability. A sol-gel material is also described.