Disclosed is a gas furnace for indoor heating. The gas furnace includes a burner to generate high-temperature exhaust gas, an exhaust flow path, a blower to suction indoor air through a recovery flow path, a supply flow path to guide the indoor air to the indoor space after undergoing heat exchange in the exhaust flow path, and a fuel supply unit including a fuel supply line and a fuel discharge line, configured to supply fuel to the burner, and a valve between the fuel supply line and the fuel discharge line. The valve includes a step motor, and a blocking member coupled to a rotating shaft of the step motor and configured to move straight via by driving of the step motor, and an opening degree of the valve between the fuel supply line and the fuel discharge line is adjusted by the straight movement of the blocking member.

An assembly includes an injection system and an injector for an aircraft turbomachine combustion chamber. The system includes an aerodynamic bowl including a first end widening toward the downstream end and centered on a central axis of the injection system, this also including a central body along which a film of fuel is intended to flow in the downstream direction. The central body includes a second end widening toward the downstream end, the first and second widening ends between them delimiting an air through duct and the system includes motion inducing a device allowing a relative movement between the first widening end which is stationary and the second widening end, along the central axis of the injection system, by moving the central body relative to the injector.

The present disclosure seeks to provide a metallic burner tile for use in industrial processes such as cracking. The tile is substantially metallic (e.g. more than 80%) with the balance being ceramic coating on surfaces exposed to high temperature. The tile is lighter and more durable than the current ceramic burners.

The invention relates to a burner unit for a furnace, in particular a continuous furnace, a tunnel furnace or the like, to a furnace and to a method for operating a furnace, the burner unit having at least two burners which are configured for burning a combustion gas, the burner unit having a gas pipe and an air pipe for supplying the burners with combustion gas, the burner unit having at least one gas metering valve in the gas pipe and at least one air metering valve in the air pipe, the gas metering valve and the air metering valve being controllable by means of a shared control device, the gas metering valve being a magnet valve and the air metering valve being a magnet valve as well.

A premixing apparatus in which a downstream end of a gas supply passage is connected to a gas suction section disposed in an air supply passage on an upstream side of a fan, is provided with: a butterfly valve driven by a stepping motor, for changing over, between high and low, a ventilation resistance in that section of the air supply passage which is on an upstream side of the gas suction section; a changeover valve for changing over, between high and low, a ventilation resistance in that section of the gas supply passage which is on an upstream side of a flow control valve; and an interlocking mechanism which opens or closes the changeover valve in interlocking with the rotation of the butterfly valve and which maintains the changeover valve in a closed state until the butterfly valve has rotated from the closed posture toward the opening side by a predetermined angle. Flame failure and poor combustion are prevented at the time of changing over the butterfly valve and the changeover valve from closed posture to opened posture. When the butterfly valve is rotated from the closed posture into the opened posture, a driving frequency of the stepping motor is made higher, until the butterfly valve has rotated from the closed posture toward the opening side by a predetermined set angle, than the driving frequency during the subsequent operation of the butterfly valve.

Sensing of gas species characteristics within a process chamber includes selectively projecting a beam of a first select lasing frequency therethough. The beam is optically coupled to a detector to detect a process transmission spectrum having an absorption dip at a select lasing frequency caused by a gas species characteristic. The beam is selectively projected through a fiber Bragg grating which is formed in an optical fiber core to partially reflect at least a portion of the beam of the first select lasing frequency while passing a remainder of the beam. The remainder of the beam has an FBG transmission spectrum mimicking the absorption dip at or near the select lasing frequency caused by a gas species characteristic of interest. It is optically coupled the detector. Outputs of the detector are monitored to compare the FBG transmission spectrum to any process transmission spectrum produced in the process chamber.

Method for operating a gas burner appliance (10), the gas burner appliance com-prising: a combustion chamber (11) in which a defined gas/air mixture is combusted after combustion has been started; a mixing device (25) to provide said gas/air mixture by mixing an air flow provided by an air duct (15) with a gas flow provided by a gas duct (16); a fan (14) to provide the air flow or the flow of the gas/air mixture; a gas safety valve unit (19) assigned to the gas duct to open or close the gas duct; a gas flow modulator (18) or a gas flow regulator (28) assigned to the gas duct to keep a mixing ratio of the defined gas/air mixture constant over the modulation range of the gas burner appliance; an absolute pressure sensor (21) positioned between the gas safety valve unit and the mixing device, wherein the gas burner appliance is operated to determine the air flow resistance of the same by executing the following steps before combustion becomes started: Measuring a first absolute pressure by the absolute pressure sensor (21) when the gas safety valve unit (19) is closed and when the fan (14) is stopped. Measuring a second absolute pressure by the absolute pressure sensor (21) when the gas safety valve unit (19) is closed and when the fan (14) is running. Determining a pressure difference between the first absolute pressure and the second absolute pressure. Determining on basis of the pressure difference the air flow resistance of the gas burner appliance.

A controller for use in a gas appliance system includes a circuit board, a plurality of connectors and a processor mounted on the circuit board. The processor controls operation of the gas appliance using, in part, at least one connector of the plurality of connectors and control settings for an intermittent pilot (IP) system in response to a user selection to configure the controller to control an IP system, and controls operation of the gas appliance using, in part, at least one connector of the plurality of connectors and control settings for a direct spark ignition (DSI) system in response to a user selection to configure the controller to control a DSI system.

An electrical step-down converter comprises a circuit input and a circuit output, which have a common reference potential, furthermore a flow-control valve having an inlet and an outlet, the inlet being connected to the circuit input; a coil, which is connected between the outlet of the flow-control valve and the circuit output; a diode, which is inserted in the forward direction from the reference potential to the outlet of the flow-control valve; an output capacitor between the circuit output and the reference potential; and a control device for periodically opening and closing the flow-control valve. A Zener diode is inserted between the anode of the diode and the reference potential with a forward direction to the reference potential and a resistor is provided in parallel to the diode.

A gas burner assembly for a cooktop appliance includes a normally aspirated primary burner and a concentrically-positioned forced air boost burner. A dual-outlet solenoid valve receives fuel from a fuel source and selectively directs the fuel to a first solenoid outlet in fluid communication with the primary burner and a second solenoid outlet in fluid communication with the boost burner. The solenoid valve is positionable in a first position where the first solenoid outlet is substantially open and the second solenoid outlet is substantially closed and a second position where the first solenoid outlet is partially open and the second solenoid outlet is substantially open.