A water heater includes a vessel (20) provided with a burner (3) having a downward combustion surface, a fan casing (10) accommodating a fan (10a) for supplying a mixture gas of primary combustion air and fuel gas to the burner, an annular packing connecting a first connection end surface at a downstream end of a first passage forming a downstream-side passage of the fan casing with a second connection end surface at an upstream end of a second passage forming an upstream-side passage of the vessel in airtight state, and a check valve (5) disposed near the upstream end in the second passage (2).

A fuel supply system for a gas burner assembly. The gas burner assembly includes an inner burner stage positioned concentrically within an outer burner stage. The fuel supply system includes a fuel supply for providing a primary flow of fuel through a primary fuel conduit and a single outlet control valve operably coupled to the primary fuel conduit. A first and second fuel supply conduit split off of the primary fuel conduit and are fluidly coupled with the outer burner stage and the inner burner stage, respectively. A shutoff valve is operably coupled to one of the first fuel supply conduit and the second fuel supply conduit and is configured for closing when a flow rate of fuel through the shutoff valve drops below a predetermined flow rate.

A system and method for recycling flare gas back to a processing facility that selectively employs different numbers of ejector legs depending on the flare gas flowrate. The ejector legs include ejectors piped in parallel, each ejector has a flare gas inlet and a motive fluid inlet. Valves are disposed in piping upstream of the flare gas and motive fluid inlets on the ejectors, and that are selectively opened or closed to allow flow through the ejectors. The flowrate of the flare gas is monitored and distributed to a controller, which is programmed to calculate the required number of ejector legs to accommodate the amount of flare gas. The controller is also programmed to direct signals to actuators attached to the valves, that open or close the valves, to change the capacity of the ejector legs so they can handle changing flowrates of the flare gas.

A system and method for recycling flare gas back to a processing facility that selectively employs different numbers of ejector legs depending on the flare gas flowrate. The ejector legs include ejectors piped in parallel, each ejector has a flare gas inlet and a motive fluid inlet. Valves are disposed in piping upstream of the flare gas and motive fluid inlets on the ejectors, and that are selectively opened or closed to allow flow through the ejectors. The flowrate of the flare gas is monitored and distributed to a controller, which is programmed to calculate the required number of ejector legs to accommodate the amount of flare gas. The controller is also programmed to direct signals to actuators attached to the valves, that open or close the valves, to change the capacity of the ejector legs so they can handle changing flowrates of the flare gas.

A combustion apparatus having: an upstream-side air supply chamber and a downstream-side mixing passage, both being respectively interposed between a fan and a burner; and a zero governor which is interposed in a gas supply passage and which adjusts a secondary gas pressure to a pressure equivalent to an internal pressure in the air supply chamber, thereby enabling to maximize a turndown ratio to the extent possible. The combustion apparatus has: first and second, totally two, mixing passages; a first gas outlet which is in communication with a narrowed part of the first mixing passage; a second gas outlet which is in communication with a narrowed part of the second mixing passage; a first air valve which varies an opening degree of an air inlet of the first mixing passage; a second air valve which varies an opening degree of an air inlet of the second mixing passage; and a gas valve.

A system for controlling activity in a combustion chamber. The system does not necessarily need to be mechanically adjusted and yet may provide precise control of a fuel air mixture ratio. A sensing module of the system may have a mass flow sensor that relates to air flow and another sensor that relates to fuel flow. Neither sensor may need contact with fuel. Fuel and air to the system may be controlled. Pressure of the fuel and/or air may be regulated. The sensors may provide signals to a processor to indicate a state of the fuel and air in the system. The processor, with reliance on a programmed curve, table or the like, often based on data, in a storage memory, may regulate the flow or pressure of the fuel and air in a parallel fashion to provide an appropriate fuel-air mixture to the combustion chamber.

Provided is a safety valve that can be satisfactorily closed. A safety valve includes a first valve port (13) and a first valve body (4) that are provided in a gas flow channel. The safety valve further includes an attracting part (3) that attracts the first valve body (4) by magnetic force. The safety valve further includes an electric drive mechanism (2) that moves the attracting part (3). The safety valve further includes a second valve port (14) and a second valve body (34) that are provided upstream of the first valve port (13). The second valve body (34) is provided on the attracting part.

A device for controlling a combustible gas supply to a heating apparatus burner includes: a valve with a respective valve seat which is associated with a corresponding closure member provided with a respective control rod for opening the valve seat, a system for amplifying movement of the control rod which has a snap-fit spring which acts on the rod and a pushing element which in turn acts on the spring, a first end of a lever acts on the pushing element which is hinged at a fulcrum location which is positioned at an opposing second end of the lever, actuator which moves the lever, operationally associated with the lever in a position between the opposing lever ends to control the lever about the fulcrum location resulting in movement of the closure member away from and towards the valve seat, the actuator comprising a linear actuator element with converse piezoelectric effect.

An apparatus for generating electricity via thermophotovoltaic (TPV) energy conversion is described. High efficiency is obtained by introducing a material into a combustion chamber that emits bright near-monochromatic visible light upon heating. This light is then directed to fall on an array of photovoltaic (PV) cells which convert the light to electricity. Heat and infrared radiation that is not absorbed by the PV cells is returned to the combustion chamber to further improve conversion efficiency.

A burner includes a hot gas zone and an outer zone, a primary air feed line, a secondary air feed line, and a fuel feed line. The secondary air feed line includes three concentric cylindrical tubes. The fuel feed line is arranged concentrically around the secondary air feed line. A first dead volume exists inside the burner between the secondary air feed line and the fuel feed line. The fuel feed line has a nozzle construction on the hot gas side. A second dead volume is arranged between the secondary air feed line and the fuel feed line on the outer side zone. The primary air feed line is arranged concentrically around the fuel feed line.