Methods and related systems for operating a furnace are disclosed. In an embodiment, the method includes activating a burner assembly and a first fan of the furnace to combust fuel and air and circulate combustion gases along a flow path extending through a heat exchanger of the furnace. In addition, the method includes operating a second fan of the furnace to circulate air across an external surface of the heat exchanger of the furnace and produce a conditioned airflow. Further, the method includes monitoring one or more parameters of a motor of the second fan indicative of an airflow rate of the conditioned airflow, and deactivating the burner assembly, whereby combustion of the fuel and air in the furnace ceases, in response to the one or more parameters indicating that the airflow rate is less than a minimum airflow rate.

This application relates to a method for controlling the combustion in furnace systems, wherein an oxygen coefficient is determined from the temperature in a combustion chamber area and/or in the waste-gas flues of the furnace system and on the basis of an energy balance of the combustion process in the furnace system, the combustion air and the waste gas, and said oxygen coefficient is used to control the combustion material flows and therefore the thermal output and also the combustion quality. The invention relates to a device for feeding combustion air in the furnace system, which device has a chamber, which on a first side has a main duct for feeding ambient air and/or air from the chimney system and on a second side has a pane-washing air duct and a secondary-air duct, both the pane-washing air duct and the secondary-air duct.

A method for continuous firing of combustion chambers with at least three regenerative burners, wherein a first regenerative burner cyclically in the combustion mode conveys supply air and a second regenerative burner in the exhaust mode conveys exhaust air. To avoid escape of hazardous process gases from the combustion chamber into the environment and high carbon monoxide emissions, and to provide energy-efficient firing operation despite use of compact regenerators, the volume flow of the supply or exhaust air through the first or second regenerative burner is reduced continuously and in counter-cycle mode to the volume flow of supply or exhaust air through a third regenerative burner at constant combustion chamber pressure until the first or second regenerative burner is flow-free.

A motor controller for a burner system includes an inverter that supplies current to a motor that rotates a draft inducer fan. A processor is coupled to the inverter and receives a signal from a system controller, and in response instructs the inverter to supply a first current, during a first period, to the motor to rotate the fan to produce a first mass flow through the burner system, the first mass flow having a first mass flow rate greater than a threshold to actuate a vacuum switch. The processor then instructs the inverter to supply a second current, during a second period starting at an expiration of the first period, to the motor to rotate the fan to produce a second mass flow through the burner system, the second mass flow having a target mass flow rate for normal operation of the burner.

A gas burner system has a gas burner with a conduit through which an air-gas mixture is conducted; a variable-speed forced-air device that forces air through the conduit; a control valve that controls a supply of gas for mixture with the air to thereby form the air-gas mixture; and an electrode configured to ignite the air-gas mixture so as to produce a flame. The electrode is further configured to measure a flame ionization current associated with the flame. A controller is configured to actively control the variable-speed forced-air device based on the flame ionization current measured by the electrode so as to automatically avoid a flame harmonic mode of the gas burner. Corresponding methods are provided.

Methods and related systems for operating a furnace are disclosed. In an embodiment, the method includes activating a burner assembly and a first fan of the furnace to combust fuel and air and circulate combustion gases along a flow path extending through a heat exchanger of the furnace. In addition, the method includes operating a second fan of the furnace to circulate air across an external surface of the heat exchanger of the furnace and produce a conditioned airflow. Further, the method includes monitoring one or more parameters of a motor of the second fan indicative of an airflow rate of the conditioned airflow, and deactivating the burner assembly, whereby combustion of the fuel and air in the furnace ceases, in response to the one or more parameters indicating that the airflow rate is less than a minimum airflow rate.

A furnace including: a blower assembly compartment; a blower assembly located within the blower assembly compartment; a blower motor located within the blower assembly compartment, the blower motor operably connected to a fan of the blower assembly; an induced draft blower; an inducer motor operably connected to the induced draft blower; and a dual motor controller located within the blower assembly compartment, the dual motor controller being configured to independently control at least one of a torque or a speed of the blower motor and the inducer motor.

In a premixing apparatus that mixes a fuel gas with air, supplies an air-fuel mixture to a burner through a fan, and carries out a control that regulates an opening degree of a variable throttle valve, which is interposed in a gas supply passage, so that an excess air ratio of an air-fuel mixture becomes an appropriate value, in a case where a detected excess air ratio deviates to one side, e.g., a large side, from an acceptable range, a motor is repeatedly caused to rotate by a unit-angle in an opening-degree increasing direction until the detected excess air ratio becomes an appropriate value. In a case where the detected air ratio deviates to the other side, e.g., a small side, from the acceptable range, the motor is caused to rotate, at a high speed in an opening-degree decreasing direction, till a first position that is anticipated that the excess air ratio will become a value that deviates by a fixed quantity from the acceptable range to a large side, thereafter, the motor is caused to rotate, at the high speed in an opening-degree increasing direction, till a second position that is a short of a target position, and subsequently, the motor is caused to rotate by the unit-angle in the opening-increasing direction.

An electronic control system for a power burner system for use with a heating appliance includes a burner tube, a gas valve for providing gas to the burner tube, an electronic control and a variable speed combustion air blower for mixing air with the gas provided to the burner tube. The electronic control system further includes a control in communication with the gas valve and the combustion air blower. The control may also be in communication with various other devices of an appliance, such as a variable speed air-circulating fan, a variable speed exhaust fan, or various sensors associated with the heating appliance. The control modulates the gas valve and the combustion air blower to maintain substantially stoichiometric conditions of the gas and air provided to the burner tube and as a function of signals from at least one of the devices. In one embodiment, the burner system may be used in a conveyor oven.

In a control method of a washing machine, a primary nephelometric turbidity unit (NTU) of washing water is sensed before a washing course is started in a washing cycle, a second NTU is sensed based on the primary NTU, and a washing time, an amount of washing agent, and/or a number of times of rinsing are varied based on a difference value between the primary NTU and the secondary NTU, thereby improving washing performance and washing efficiency.