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.

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.

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.

The present invention relates to a gas burner system (10) for a gas cooking hob, in particular for a domestic gas cooking hob. Said gas burner system (10) comprises a gas burner assembly (12) including a plurality of flame ports. At least one pot support (14) is arranged above and/or around the gas burner assembly (12) and defining a distance between said gas burner assembly (12) and a bottom of a cooking pot. At least one supply air fan (16) is provided for generating an air flow (24) to the gas burner assembly (12). A gas inlet (38) is connectable or connected to a gas supply. A gas regulator (18; 30; 36; 38) is provided for regulating a gas flow from the gas inlet (38) to the gas burner assembly (12). A control unit (20) is provided for controlling the supply air fan (16) and the gas regulator (18; 30; 36; 38). At least one thermocouple (22) is provided for detecting flames above the gas burner assembly (12) and for providing a flame signal (28) to the control unit (20).

A pressure probe assembly for attachment to a venturi of a gas-fired appliance, where the venturi includes a body having an inlet end, an outlet end, and a wall defining a mixing chamber extending from the inlet end to the outlet end about an axis. A support member is detachably coupled to the mixing chamber. A first pressure probe is coupled to the support member and has a first pressure tap disposed substantially adjacent the axis. A second pressure probe is coupled to the support member and has a second pressure tap disposed substantially adjacent the mixing chamber wall. Also disclosed is a gas-fired appliance, such as a water heater, including the pressure probe assembly.

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 variable orifice flow meter system includes a housing defining a flow passage and at least one plate extending into the flow passage and defining an orifice. The at least one plate is movably supported such that a size of the orifice may be adjusted. Upstream and downstream pressure sensors may measure fluid pressures upstream and downstream of the orifice and a drive mechanism may move the at least one plate. A controller may instruct the drive mechanism to move the at least one the plate such that a predetermined orifice size is defined in response to detecting an upstream pressure within a predetermined pressure range, determine a pressure differential across the orifice and calculate a flow rate through the flow passage based on the pressure differential when the pressure differential meets a predetermined threshold.

Exemplary embodiments are disclosed of systems including electronic differential pressure sensors for electronically controlling stepper gas valves to modulate fuel flow in PAM combustion systems (e.g., PAM furnace systems, etc.). Also disclosed are exemplary methods for electronically modulating fuel flow in pressure augmented modulation (PAM) combustion systems.

A method and a boiler for burning a liquid or gaseous fuel. The boiler comprises a boiler housing with a cylindrical heat exchanger arranged therein and has slot-like pass-through openings for the combustion gases and has a flame tube. A flame-deflecting part for deflecting the combustion gases at a right angle is provided at an axial distance from the flame tube. The flame tube contains a baffle plate with a faceplate through which combustion air is fed into the flame tube. A blower ensures the supply of combustion air into the combustion chamber. Blower pressure is so that a differential pressure zone with a differential pressure of at least 0.25 mbar is generated between the flame tube and the heat exchanger, downstream of the faceplate at full load of the burner in relation to the pressure in the combustion chamber in the region of the recirculation slots.

The disclosed technology includes systems and methods for detecting an obstructed air filter in a furnace. The disclosed technology can include a method and system that includes an air inlet, an air filter for filtering particles from air passing through the air inlet, an air moving device, a fuel valve, a burner, a pressure sensor, and a controller in communication with the pressure sensor and configured to output an alarm signal when the controller receives differential pressure data from the pressure sensor that indicates that the air filter is obstructed.