A premixing apparatus for mixing air with a fuel gas to supply a burner with an air-fuel mixture via a fan includes: a zero governor and a motor-driven type of variable throttle valve, both being disposed in a gas supply passage; and an excess air ratio detecting device for detecting an excess air ratio of the air-fuel mixture, thereby regulating an opening degree of the variable throttle valve so that the excess air ratio of the air-fuel mixture becomes a predetermined value. An arrangement is made to prevent an ignition failure from occurring in an attempt to perform an ignition operation in a state in which, due to a trouble with the variable throttle valve of remaining opened or remaining closed, the excess air ratio of the air-fuel mixture becomes too small or too excessive. The variable throttle valve is provided with a sensing device.

A premixing apparatus for mixing air with a fuel gas to supply a burner with an air-fuel mixture via a fan includes: a zero governor and a motor-driven type of variable throttle valve, both being disposed in a gas supply passage; and an excess air ratio detecting device for detecting an excess air ratio of the air-fuel mixture, thereby regulating an opening degree of the variable throttle valve so that the excess air ratio of the air-fuel mixture becomes a predetermined value. An arrangement is made to prevent an ignition failure from occurring in an attempt to perform an ignition operation in a state in which, due to a trouble with the variable throttle valve of remaining opened or remaining closed, the excess air ratio of the air-fuel mixture becomes too small or too excessive. The variable throttle valve is provided with a sensing device.

In some examples, a gas/air mixing device configured to mix gas and air to provide a gas/air mixture includes a mixer housing with a mounting flange being configured to mount the gas/air mixing device to a fan housing in such a way that a sealing surface of the mounting flange is in contact with a sealing surface of the fan housing. In some examples, the sealing surface of the mounting flange has grooves with a second radius being different from the first radius. In some examples, the sealing surface of the fan housing has a groove, with a second radius being different from the first radius. The mixer housing provides an inlet opening for air, an inlet opening for gas, and an outlet opening for the gas/air mixture. The sealing surface of the mounting flange surrounds the outlet opening of the mixer housing.

In some examples, a gas/air mixing device configured to mix gas and air to provide a gas/air mixture includes a mixer housing with a mounting flange being configured to mount the gas/air mixing device to a fan housing in such a way that a sealing surface of the mounting flange is in contact with a sealing surface of the fan housing. In some examples, the sealing surface of the mounting flange has grooves with a second radius being different from the first radius. In some examples, the sealing surface of the fan housing has a groove, with a second radius being different from the first radius. The mixer housing provides an inlet opening for air, an inlet opening for gas, and an outlet opening for the gas/air mixture. The sealing surface of the mounting flange surrounds the outlet opening of the mixer housing.

A biomass burner includes a hopper, a ventilating chamber, a U-shaped fire box, a feeding cylinder including an output end, an auger, a feeding motor including a driving wheel, an ignition device, an ignition motor, a ventilation plate, a first poking device, a second poking device, a first poking motor configured to drive the first poking device, a second poking motor configured to drive the second poking device, a first fixed plate, and a second fixed plate. The hopper is disposed below the feeding cylinder. The feeding cylinder is disposed through the ventilating chamber and the output end of the feeding cylinder extends into the U-shaped fire box. The auger is disposed in the feeding cylinder and is driven by the feeding motor; one end of the auger is provided with a driven gear, and the driven gear is meshed with the driving wheel of the feeding motor.

A biomass burner includes a hopper, a ventilating chamber, a U-shaped fire box, a feeding cylinder including an output end, an auger, a feeding motor including a driving wheel, an ignition device, an ignition motor, a ventilation plate, a first poking device, a second poking device, a first poking motor configured to drive the first poking device, a second poking motor configured to drive the second poking device, a first fixed plate, and a second fixed plate. The hopper is disposed below the feeding cylinder. The feeding cylinder is disposed through the ventilating chamber and the output end of the feeding cylinder extends into the U-shaped fire box. The auger is disposed in the feeding cylinder and is driven by the feeding motor; one end of the auger is provided with a driven gear, and the driven gear is meshed with the driving wheel of the feeding motor.

A combustion device including a chamber, a burner, a fan case, and a fan is provided. The chamber has a top wall. On the top wall, an inflow port penetrating through the top wall along a first direction and in communication with an internal space of the chamber is formed. The burner is attached to the chamber, so as to be spaced apart from and face the top wall in the first direction. In the fan case, a discharge port and an intake port penetrating through the fan case along the first direction and in communication with an internal space of the fan case are formed. The discharge port is connected with the inflow port. The fan is provided in the internal space of the fan case. A rotation axis of the fan is along the first direction.

A combustion device including a chamber, a burner, a fan case, and a fan is provided. The chamber has a top wall. On the top wall, an inflow port penetrating through the top wall along a first direction and in communication with an internal space of the chamber is formed. The burner is attached to the chamber, so as to be spaced apart from and face the top wall in the first direction. In the fan case, a discharge port and an intake port penetrating through the fan case along the first direction and in communication with an internal space of the fan case are formed. The discharge port is connected with the inflow port. The fan is provided in the internal space of the fan case. A rotation axis of the fan is along the first direction.

A vehicle heater includes a heater housing (12) elongated in a direction of a housing longitudinal axis (L). A housing circumferential wall (34) defines a combustion air flow space (40). A combustion chamber assembly unit (14) is carried on the heater housing and has a combustion chamber (20) receiving combustion air from the combustion air flow space. A combustion air blower (42), with a combustion air blower housing (44), is carried on the heater housing. A combustion air inlet opening (56), in the combustion air blower housing, provides the inlet for combustion air into the combustion air blower. A combustion air connection unit (64), carried on the heater housing, has a combustion air passage duct (74) open outwardly in a first duct opening area (76) for receiving combustion air. The combustion air passage duct is open towards the combustion air inlet opening in a second duct opening area (78).

Exemplary embodiments of a system and method for bimodal air control in a kettle-style grill are configured to be detachably mounted to the exterior of a kettle-styled grill such as, but not limited to, a Weber® charcoal grill. When mounted to the kettle-styled grill, a plenum-like component directs air flows to the interior of the grill's kettle via the kettle's lower body damper holes. A manually adjustable intake damper in the plenum component allows, restricts, or prevents a drawn ambient air flow into the plenum component. Separately, a forced air flow generated by a fan may also be provided into the plenum component. Adjustment of the intake damper may also adjust damper blades inside the grill's kettle. Ash that falls out of the kettle's damper holes falls through the plenum component and is captured in an ash receptacle that is removably mounted to the plenum component.