A flue gas analyser for determining the efficiency of a burner burning a supply gas and producing a flue gas by: calculating an efficiency of the burner based on a detected amount of a first target gas in the flue gas and an expected amount of the first target gas in the flue gas; predicting an amount of a second target gas in the flue gas based on the efficiency of the burner; estimating a composition of the supply gas based on a detected amount of the second target gas in the flue gas and the predicted amount of the second target gas in the flue gas; and correcting the calculated efficiency of the burner based on the estimated composition of the supply 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 turn down ratio (TDR) damper which controls an amount of gas and air flowing in the TDR damper and deliver the controlled gas and air to a turbo fan is disclosed. The TDR damper includes: air passages comprising a first air passage and a second air passage, the first air passage and the second air passage separately formed so that the air move through each path; gas passages comprising a first gas passage and a second gas passage, the first gas passage and the second gas passage separately formed so that the gas move through each path; and opening and closing means for opening and closing the second air passage and the second gas passage at the same time. The air passages and the gas passages may be separately formed and reached outlets connected to the turbo fan so that the air and gas may be delivered to the turbo fan through a separate path.

Disclosed is a gas heater, including: a gas bottle for storing a gas, a valve body connector, and a burner. A cavity is provided in the valve body connector, both the regulator and the safety valve are communicated with the cavity, the regulator is connected to the gas bottle, the valve body connector is provided with a valve nozzle, and the valve nozzle is communicated with the cavity. An air inlet pipe is provided between the burner and the valve body connector, one end of the air inlet pipe is connected to the valve nozzle, another end of the air inlet pipe is connected to the burner. The gas enters the cavity of the valve body connector through the regulator, and enters the air inlet pipe through the valve nozzle.

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.

This disclosure relates generally to valves, and more particularly, to gas valve assemblies. In one example, a gas valve assembly may include a valve body with one or more valves movable between an opened position and a closed position, one or more valve actuators configured to operate the valves, and one or more pressure sensors to sense a pressure within a fluid path of the valve assembly. A valve controller may receive a measure related to a sensed pressure from the one or more pressure sensor(s). The valve controller may compare the received measure related to the sensed pressure to an overpressure threshold. In the event the measure related to the sensed pressure surpasses the overpressure threshold value, the valve controller may be configured to provide a signal that indicates an overpressure event has occurred.

The present invention describes a device for delivering a combustible gaseous mixture (M) comprising a first duct for feeding air (A) and a second duct for feeding a gaseous fuel (G), which join in a mixing zone, in which the gaseous fuel (G) and air (A) mix according to a lambda coefficient () before being sent to a burner, a ventilation device for feeding the air (A) and at the same time suctioning gaseous fuel (G) along said ducts, and means for regulating the flow rate of gaseous fuel (G). The invention also concerns a method to use a device for delivering a combustible gaseous mixture (M).

A premixing device which includes a premixing flow path including a first flow path and a second flow path, and a first fuel gas outlet and a second fuel gas outlet includes: a first blade section which is provided in the first flow path, and with which the first fuel gas outlet is provided; a protruding wall section which is provided on the first blade section; and a flapper which oscillates at a position downstream in the air flow direction than the first blade portion of the first flow path. When the flapper is in an open state below a specified opening degree, the flow of air from the first flow path to the first fuel gas outlet is capable of being suppressed by the protruding wall section.

Disclosed is a gas heater, including: a gas bottle for storing a gas, a valve body connector, and a burner. A cavity is provided in the valve body connector, both the regulator and the safety valve are communicated with the cavity, the regulator is connected to the gas bottle, the valve body connector is provided with a valve nozzle, and the valve nozzle is communicated with the cavity. An air inlet pipe is provided between the burner and the valve body connector, one end of the air inlet pipe is connected to the valve nozzle, another end of the air inlet pipe is connected to the burner. The gas enters the cavity of the valve body connector through the regulator, and enters the air inlet pipe through the valve nozzle.