Various embodiments of the teachings herein include a mixer disposed in a fuel gas combustion system and mixing air and fuel gas to form flammable mixed gases. The mixer may include: a Venturi tube having an air inlet, a fuel gas inlet, a gas mixture outlet, a central axis direction, and a throat positioned between the air inlet and the gas mixture outlet in the central axis direction, wherein the fuel gas inlet is disposed at the throat; and an adjustment component disposed in the Venturi tube downstream of the throat, the adjustment component drivable to move towards or away from the throat in the central axis direction, thereby changing a flow area of gas in the Venturi tube. The adjustment component comprises a conical valve plug with a conical outer surface thereof at a side facing towards the throat and fitting an inner surface of the Venturi tube.

Provided is an RPM control method for an inducer for a gas furnace that induces a flow of combustion gas produced in a burner from a heat exchanger to an exhaust pipe. The RPM control method for an inducer for a gas furnace includes: (a) initiating a heating operation for the gas furnace; (b) determining whether the operation time during which the heating operation is performed is equal to or longer than a first time period; (c) if it is determined that the operation time is equal to or longer than the first time period, detecting whether a pressure switch is turned OFF; and (d) if the pressure switch is detected as turned OFF, increasing the RPM of the inducer by a first value.

A method of calibrating a furnace includes determining a first flame stabilization period for the furnace that avoids detachment of a flame from a burner within a burner box of the furnace, determining a second flame stabilization period that is longer than the first flame stabilization period and avoids emission of a combustion tone from the furnace, and configuring a controller of the same or another furnace to utilize a flame stabilization period that has a duration between the first and second flame stabilization periods. Each flame stabilization period commences upon ignition of a premixed mixture of air and fuel at the burner while an inducer fan operates within a first range of fan speeds, and terminates when the rotational speed of the inducer fan increases to a second range speeds that is greater than the entire first range.

A reactor safety device includes a leg and a well. The leg includes an inlet and an outlet. The inlet is in fluid communication with an outlet of a reactor configured to operate at a pressure less than atmospheric pressure at a location of the reactor safety device. The well includes an inlet in fluid communication with the outlet of the leg. There is a first level in the leg and a second level in the well. The outlet of the leg is vertically lower than the second level. A level sensor is configured to monitor the first level and a controller in communication with the level sensor, a fuel inlet into the reactor, and an oxidant inlet into the reactor. The controller is configured to close the fuel inlet and the oxidant inlet when the first level changes by a predetermined amount.

A method for controlling a combustion apparatus having a combustion state in which a parameter related to the combustion state reflects a chaotic behavior is provided. The method includes the steps of measuring the parameter and determining a time series of the parameter, shifting the time series by a variable time delay for determining a time-shifted signal, and forming a difference between the time-shifted signal and the time series for determining a time dependent first signal, so that a norm of the difference is lowest. A time dependent second signal is determined, wherein determining the time dependent second signal includes at least one of using a frequency of a desired oscillating combustion state, and shifting the time series by a set time delay. The first signal and the second signal are combined to determine a control signal. The control signal is used to influence the combustion apparatus.

A burner appliance is disclosed. The burner appliance includes a byproduct sensor in an exhaust flue and/or a barometric pressure sensor to detect an environmental pressure at the burner appliance. By calculating concentrations of combustion byproducts in the exhaust with the byproduct sensor, a controller can adjust blower speed and/or fuel rate to modify combustion efficiency. By calculating the environmental pressure at the burner with the barometric pressure sensor, the controller can adjust blower speed and/or fuel rate to modify combustion efficiency. The barometric-pressure data can also be used to adjust blower speed control bands, thereby calibrating the control bands based on environmental pressure. The environmental pressure can be indicative of altitude and/or weather conditions. Methods of operating said burner appliance are also disclosed.

The invention refers to a method for detecting anomalies associated with a gas appliance (1), the gas appliance (1) comprising at least a gas inlet (2), at least one gas burner (3) and gas distribution means (4) coupling the gas inlet (2) with said at least one gas burner (3), the method comprising the steps of: —gathering information regarding the gas flow or the operational state based on detection means (5.1, 5.2) (S20); —evaluating said gathered information in order to detect gas flow anomalies or operational anomalies, thereby obtaining evaluation information (S21); —providing alert information from a communication interface of the gas appliance (1) to a user device (6) depending on said evaluation information (S22).

The present invention relates to a boiler which determines a clogging degree of an exhaust flue through which combustion gas is discharged and adjusts gas supply amount to maintain its combustibility, and a combustion control method thereof, the method of the present invention including a) setting a target heat value for achieving a target temperature, b) applying a first database on the basis of the target heat value, c) measuring a rotational speed of an air blower and a pneumatic pressure of air introduced by rotation of the air blow, d) applying a second database on the basis of a rotational speed difference, a pneumatic pressure difference, and the target heat value to calculate an estimated flue clogging value according to the target heat value, and a) applying a third database according to the estimated flue clogging value to calculate an opening amount of a gas valve and control gas supply amount.

A mounting system for mounting a pressure switch to a mounting body without using screws or brackets. The mounting system includes a support physically supporting the pressure switch on the mounting body, a conduit carrying a pressure signal from the mounting body to the pressure switch, and a connector extending between and connecting the support to the conduit. The support and conduit may have ends constructed of synthetic rubber to frictionally engage support and conduit mounts, and the support and conduit may have approximately the same length and/or the same cross-sectional shape. The mounting body may be a draft inducer, a condensate collector box, or a drain trap in a furnace.

A fluid heating system including a burner unit is operated based on feedback control loops. The fluid heating system comprises a burner unit configured to heat a fluid, a sensor configured to sense a characteristic of the appliance, and a controller coupled to the burner unit and the sensor. The controller includes an electronic processor and a memory. The controller is configured to receive a first signal corresponding to the characteristic from the sensor, determine, based on the first signal, a first feedback loop control, control combustion of the burner unit based on the first feedback loop control, determine, based on the first feedback loop control, a second feedback loop control, and control combustion of the burner unit based on the second feedback loop control.