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 burner 100 comprising a burner body 110 having a burner chamber with a backing plate 122 and having a burner element received in the burner chamber, the burner element having a plurality of gas nozzles 117 for supplying gas into the burner, the gas nozzles 117 each ending in a tip through which the gas exits and gas nozzle 117, and each gas nozzle being rotatable such that the direction of gas exiting the gas nozzle can be adjusted. The burner has means for rotating the gas nozzles 117 provided on the backing plate and by releasable means for retaining each gas nozzle 117 in a plurality of rotational configurations provided outside the burner chamber. The gas nozzles 117 further comprise first and second parts which are detachable from each other, the first part comprising the tip and the second part being upstream of the first part with respect to the flow of gas into the gas nozzles in use. The burner allows for tuning of gas flow from outside the burner while it is in use.

A humidifier includes a base configured to retain a body of liquid therein, a top cover, and a seal disposed between the top cover and the base. At least a portion of the base is constructed of a heat conducting material. The top cover defines both an inlet and an outlet communicated with an interior of the base. The inlet is configured to receive pressurized breathable gas and the outlet is configured to deliver the pressurized breathable gas with added humidity.

Provided is a boiler for heating fluid by a heat generation unit including heat generation bodies in a container, the boiler being able to moderately heat fluid according to various situations while heat generated by the heat generation bodies can be efficiently utilized. A boiler for heating fluid by using heat generated by heat generation bodies includes the heat generation bodies and a container having the heat generation bodies inside and configured such that the inside of the container is filled with gas with higher specific heat than that of air. The boiler includes a controller configured to control a heat generation amount of the heat generation body under a situation where the gas has been supplied into the container.

A fluid mixer configured to stably supply a mixed fluid having a desired mixing ratio, and which can be reduced in size. This fluid mixer includes a Venturi tube having a constriction section at which the flow path area is reduced, the Venturi tube having formed therein a first inflow opening and a second inflow opening through which a second fluid flows into a low-pressure region produced due to an increase in fluid velocity when a first fluid passes through the constriction section. A valve body that is disposed within the Venturi tube, the valve body closing due to the pressure of the first fluid passing through the Venturi tube and changing the flow path area of the Venturi tube, blocking off the first inflow opening when closed, and opening the first inflow opening when opened; and a biasing part (elastic body) applying a biasing force in the valve closing direction of the valve body.

A fluid mixer configured to stably supply a mixed fluid having a desired mixing ratio, and which can be reduced in size. This fluid mixer includes a Venturi tube having a constriction section at which the flow path area is reduced, the Venturi tube having formed therein a first inflow opening and a second inflow opening through which a second fluid flows into a low-pressure region produced due to an increase in fluid velocity when a first fluid passes through the constriction section. A valve body that is disposed within the Venturi tube, the valve body closing due to the pressure of the first fluid passing through the Venturi tube and changing the flow path area of the Venturi tube, blocking off the first inflow opening when closed, and opening the first inflow opening when opened; and a biasing part (elastic body) applying a biasing force in the valve closing direction of the valve body.

An air swirler arrangement comprises a coaxial arrangement of an inner and an outer air swirler passage. Each air swirler passage comprises a radial flow swirler. Air swirler arrangement comprises a coaxial arrangement of first, second and third members. Second member has radially extending upstream portion spaced axially from first member and a convergent portion. Third member has a radially extending upstream portion spaced axially from the upstream portion of second member and a radially inner surface having convergent and divergent downstream portions and a radially outer surface having a divergent downstream portion. First, second and third members the vanes of the radial flow swirlers is a monolithic structure. Plurality of circumferentially spaced passages are provided within the third member and each passage has an inlet in the surface and an outlet arranged to direct fluid onto the divergent portion of the surface or the surface of the third member.

An air swirler arrangement comprises a coaxial arrangement of an inner and an outer air swirler passage. Each air swirler passage comprises a radial flow swirler. Air swirler arrangement comprises a coaxial arrangement of first, second and third members. Second member has radially extending upstream portion spaced axially from first member and a convergent portion. Third member has a radially extending upstream portion spaced axially from the upstream portion of second member and a radially inner surface having convergent and divergent downstream portions and a radially outer surface having a divergent downstream portion. First, second and third members the vanes of the radial flow swirlers is a monolithic structure. Plurality of circumferentially spaced passages are provided within the third member and each passage has an inlet in the surface and an outlet arranged to direct fluid onto the divergent portion of the surface or the surface of the third member.

A combustion tube assembly of a water heater includes a combustion tube having an open end, a closed end, and an outflow opening located between the open end and the closed end. A cavity of the combustion tube provides a chamber for a combustion of a water heater fuel that produces an exhaust gas that flows down toward the closed end. The combustion tube assembly further includes a diverter structure positioned inside the combustion tube to divert the exhaust gas such that the exhaust gas flows toward the closed end on a first side of the diverter structure and flows from the first side of the diverter structure to the second side of the diverter structure through a flow opening proximal to the closed end. The outflow opening provides an outlet for the exhaust gas that flows to the second side of the diverter structure to exit the combustion tube.

A heat exchanger for a cooking system is provided. The heat exchanger includes a central axis, an inlet module, and a heat exchanger module removably coupled to and adjacent the inlet module along the central axis. A fluid duct is provided that extends through the inlet module and the heat exchanger module along the central axis. The inlet module includes a plurality of headers positioned about an outer perimeter of the inlet module, a plurality of tubes extending radially across the fluid duct between the plurality of headers, and a plurality of caps coupled to the plurality of headers, wherein each cap is configured to be removed from a corresponding one of the plurality of headers to expose one of the plurality of tubes through the corresponding one of the plurality of headers.