A non-return valve for a flow channel has a housing and an outflow opening that can be closed by a pivoting blocking flap. The blocking flap has a dome-shaped bulge. An opening edge of the outflow opening has a hinge region for the blocking flap that transitions into a blocking flap stop region circumferentially opposite the hinge region. The blocking flap stop region is offset so that the opening edge has a progression that is curved in the circumferential direction and in the outflow direction. The housing has an indentation in the circumferential direction, which is not closed by the blocking flap such that the indentation forms a condensate chamber when the housing is inserted into the surrounding flow channel. The indentation is equipped with a flow opening, through which a condensate accumulating in the condensate chamber delimited by the indentation can flow in the interior of the housing.

A furnace including a combustion chamber for burning fuel can have increased fuel burning efficiency, increased heating efficiency, and decreased harmful emissions of combustion byproducts. A combustion air delivery system delivers primary and secondary combustion air to the combustion chamber. Primary and secondary combustion air may be delivered at amounts that increase burning efficiency. An amount of secondary combustion air can be controlled by a valve system. A heat transfer device efficiently transfers heat from products of combustion for heating an enclosed space.

A damper regulator for controlling the opening/closing characteristics of an HVAC damper has a swing arm coupled to the shaft on which the damper pivots. The swing arm has an arm carriage mounted to translate on the swing arm as the swing arm pivots, and a biasing spring connects the arm carriage to the damper regulator's housing, or to another suitable anchor. The translation of the arm carriage effectively adapts the characteristics of the biasing spring so that the damper need not be subjected to ever-increasing pressure to achieve greater airflow, or so that other damper opening characteristics can be achieved.

Disclosed in the present disclosure is a biomass fuel burning furnace, including: a furnace body, provided with a first air inlet and a fuel inlet, provided with a first combustion chamber, a second combustion chamber, and a third combustion chamber sequentially communicating within the furnace body, wherein the first combustion chamber is used to receive biomass fuel, the second combustion chamber is used for a combustion of the flue gases and for obtaining a mixture to be combusted, and the third combustion chamber is used for directing a flame resulting from the combustion of flue gases in the mixture to be combusted; a fuel-input funnel for feeding biomass fuel; and a revolving door for an opening or a closure of the adjustable air inlet on the fuel-input funnel.

A damper assembly for minimizing heat loss through an exhaust stack includes a housing mountable within the stack and an umbrella received within the housing. The umbrella is selectively movable between a first position in which the umbrella is received within the housing, and second position in which the umbrella is extended from the housing such that a peripheral edge of the umbrella is in close association with an interior sidewall of the exhaust stack to minimize a flow of fluid past the umbrella and out of the stack.

A damper assembly for minimizing heat loss through an exhaust stack includes a housing mountable within the stack and an umbrella received within the housing. The umbrella is selectively movable between a first position in which the umbrella is received within the housing, and second position in which the umbrella is extended from the housing such that a peripheral edge of the umbrella is in close association with an interior sidewall of the exhaust stack to minimize a flow of fluid past the umbrella and out of the stack.

In a stack leading from a fired heater, a plurality of damper blades are positioned at a longitudinal location, each blade being at least partly rotatable around its longitudinal axis to regulate flow through the stack. A plurality of controllers is operatively associated with the plurality of parallel blades to effect rotation of the blades. At least one of the controllers is decoupled from the rest of the plurality of controllers and used to independently control at least one but not all of the plurality of damper blades. The damper blades can be parallel or opposed.

In a stack leading from a fired heater, a plurality of damper blades are positioned at a longitudinal location, each blade being at least partly rotatable around its longitudinal axis to regulate flow through the stack. A plurality of controllers is operatively associated with the plurality of parallel blades to effect rotation of the blades. At least one of the controllers is decoupled from the rest of the plurality of controllers and used to independently control at least one but not all of the plurality of damper blades. The damper blades can be parallel or opposed.

Methods, burner, apparatuses, and systems are provided for controlling a velocity of a jet of gas exiting a burner when the gas is heated or not and at a corresponding second higher temperature or lower first temperature. Through the use of a temperature-sensitive magnetic valve, the flow of a gas can be redirected to maintain velocity of the gas as delivered to a combustion chamber based on the temperature of the gas. The temperature-sensitive magnetic valve can redirect flow of the gas based on the magnetic state of a ferromagnetic material. The state of the temperature-sensitive magnetic valve changes based on the temperature of the gas to maintain the velocity of the gas delivered through an outlet of the burner to the combustion chamber. Thus, heated gases and standard temperature gases can be delivered at approximately equal velocities thus maintaining flame size and shape.

Methods, burner, apparatuses, and systems are provided for controlling a velocity of a jet of gas exiting a burner when the gas is heated or not and at a corresponding second higher temperature or lower first temperature. Through the use of a temperature-sensitive magnetic valve, the flow of a gas can be redirected to maintain velocity of the gas as delivered to a combustion chamber based on the temperature of the gas. The temperature-sensitive magnetic valve can redirect flow of the gas based on the magnetic state of a ferromagnetic material. The state of the temperature-sensitive magnetic valve changes based on the temperature of the gas to maintain the velocity of the gas delivered through an outlet of the burner to the combustion chamber. Thus, heated gases and standard temperature gases can be delivered at approximately equal velocities thus maintaining flame size and shape.