A system for increasing flue gas side draft in a heater or boiler assembly is disclosed utilizing an impeller assembly to enable an increase in firing rates beyond the ability of the exhaust stack and to reduce the size of the low flue gas side pressure drop heat pipe air preheaters.

A movable steam vent system is provided. The system includes a base and at least one pipe member. The base includes a tapered outer surface defined by an outer wall, a frustoconical inner surface defined by an inner wall, a plurality of ribs extending from the inner surface, the inner wall and the outer wall defining a space therebetween, the base further having an opening in an upper surface, the opening having a slot therein, the opening being in fluid communication with a hollow interior defined by the inner wall, the inner wall having an end that is sized to cover the subsurface space opening. The at least one pipe member is removably coupled to the base, the at least one pipe member having a having an outer wall, an inner wall, the inner wall defining a hollow interior that is in fluid communication with the base hollow interior.

A ventilator (10) comprises a ventilator stator (12) for mounting to a structure and a ventilator rotor (14) for mounting and rotation with respect to the stator. One or more wind-drivable elements (44) are mounted to the ventilator rotor. A motor (20) is provided for operation between the ventilator rotor and ventilator stator for selective motor-driven rotation of the ventilator rotor.

The invention provides a motor-driven chimney draft system with a flue gas inlet, a flue gas outlet, a flue gas compartment in fluid communication with the flue gas inlet and with the flue gas outlet, the flow of flue gases in the flue gas compartment having a flow direction from the flue gas inlet to the flue gas outlet, a motor compartment with motor having a motor shaft extending through a separating wall of the flue gas compartment, the motor shaft carrying an impeller for driving the received flow of flue gases in the flow direction; each of the separating wall of the flue gas compartment and the separating wall of the motor compartment extends parallel to the flow direction of flue gases, and they are arranged facing each other so as to define an air space therebetween, where the air space has openings allowing ambient air to flow through the air space.

A high efficiency heating apparatus for heating fluids and cooking mediums, such as oil or shortening within a fryer, includes a natural draft (non powered) combustion chamber that is affixed to an exterior surface of a fry tank.

Systems for controlling an exhaust gas fan system. The control system may control one or more components of the exhaust system to optimize system performance and improve energy efficiency. The control system may be designed to maintain a substantially constant pressure in the exhaust header and provide a substantially constant flow through the exhaust fans. The control system is configured to control one or more of: modulation of one or more by-pass dampers; adjustment of the nozzle outlet area; varying the speed of the fans; the number and staging of fans.

A furnace inducer choke and a gas furnace employing the furnace inducer choke. In one embodiment, the furnace inducer choke includes: (1) a choke body configured to engage a furnace inducer blower, the choke body having an opening extending entirely therethrough to limit an amount of combustion air entering a furnace that the furnace inducer blower is attached, and (2) a tab protruding from the choke body a distance sufficient to identify the opening when the choke body and furnace inducer blower are installed in the furnace.

A water heater capable of cooling a fan by inflow of air while suppressing backflow of combustion gas is provided. A fan includes: a fan case having a back surface wall; an impeller having a first blade and a second blade and housed in the fan case; a drive source rotating the impeller; and a rotation shaft coupling the impeller and the drive source through a through hole provided in the back surface wall. A gap through which air outside the fan case is suctioned into the fan case is provided between the rotation shaft and the back surface wall. The second blade faces the back surface wall without another member interposed therebetween throughout a range from an inner circumferential side to an outer circumferential side of the second plane.

A combined combustion device comprises: a plurality of combustion units (2) each having a burner (4) and an air supply fan (5); an exhaust collecting pipe (10) connecting the plurality of the combustion units (2) to each other; and a check valve (7) which opens by rotation of the air supply fan (5) and prevents backflow of combustion exhaust gas from the exhaust collecting pipe (10) into each of the combustion units (2), wherein when one or more of the combustion units (2) among the plurality of the combustion units (2) are in a combustion operation state and the other one or more of the combustion units (2) are continuously maintained in a non-combustion operation state for a predetermined reference stoppage time or longer, the air supply fans (5) of the other one or more of the combustion units (2) are rotated for a certain time.

A combined combustion device comprises: a plurality of combustion units (2) each having a burner (4) and an air supply fan (5); an exhaust collecting pipe (10) connecting the plurality of the combustion units (2) to each other; and a check valve (7) which opens by rotation of the air supply fan (5) and prevents backflow of combustion exhaust gas from the exhaust collecting pipe (10) into each of the combustion units (2), wherein when one or more of the combustion units (2) among the plurality of the combustion units (2) are in a combustion operation state and the other one or more of the combustion units (2) are continuously maintained in a non-combustion operation state for a predetermined reference stoppage time or longer, the air supply fans (5) of the other one or more of the combustion units (2) are rotated for a certain time.