A cylindrical burner apparatus and method which produce low NO.sub.x emissions and low noise levels without being dependent upon a blower, or natural draft, for providing air flow or flue gas recirculation. A flow of combustion air is induced into the initial tube pass of the burner by discharging a gas fuel from a plurality of discharge ports located in the initial tube pass. At the same time, a flow of recycled flue gas is induced through a bypass duct between a subsequent tube pass of the burner and the initial tube pass by discharging one or more jets of gas fuel through the bypass duct.

A cylindrical burner apparatus and method which produce low NO.sub.x emissions and low noise levels without being dependent upon a blower, or natural draft, for providing air flow or flue gas recirculation. A flow of combustion air is induced into the initial tube pass of the burner by discharging a gas fuel from a plurality of discharge ports located in the initial tube pass. At the same time, a flow of recycled flue gas is induced through a bypass duct between a subsequent tube pass of the burner and the initial tube pass by discharging one or more jets of gas fuel through the bypass duct.

A welding torch having a nozzle assembly with multiple attachment methods is disclosed. The nozzle assembly includes a nozzle shell, an electrically insulating sleeve, and a nozzle insert. The nozzle insert is configured for attachment to gas diffuser assemblies with different attachment mechanisms (e.g. a slip-on mechanism relying on frictional force, and/or screw-on mechanism relying on torque).

A welding torch having a nozzle assembly with multiple attachment methods is disclosed. The nozzle assembly includes a nozzle shell, an electrically insulating sleeve, and a nozzle insert. The nozzle insert is configured for attachment to gas diffuser assemblies with different attachment mechanisms (e.g. a slip-on mechanism relying on frictional force, and/or screw-on mechanism relying on torque).

A method of controlling a premixing apparatus that mixes fuel gas with air and supplies thus obtained air-fuel mixture, through a fan to a burner, includes at a time of changing over to a small-capacity state in which a first ventilation resistance in an air supply passage is increased and also in which a second ventilation resistance in a gas supply passage is increased, rotating a butterfly valve down to a closing side stop angle; and at a time of changing over to a large-capacity state in which the first ventilation resistance in the air supply passage is decreased and also in which the second ventilation resistance in the gas supply passage is decreased, rotating the butterfly valve up to an open-side stop angle.

A method of controlling a premixing apparatus that mixes fuel gas with air and supplies thus obtained air-fuel mixture, through a fan to a burner, includes at a time of changing over to a small-capacity state in which a first ventilation resistance in an air supply passage is increased and also in which a second ventilation resistance in a gas supply passage is increased, rotating a butterfly valve down to a closing side stop angle; and at a time of changing over to a large-capacity state in which the first ventilation resistance in the air supply passage is decreased and also in which the second ventilation resistance in the gas supply passage is decreased, rotating the butterfly valve up to an open-side stop angle.

An innovative oxyhydrogen (HHO) burner system including one or more burner systems is provided to eliminate emissions through total combustion. Each burner system includes at least one HHO gas supply and an external natural gas supply, both of which are connected to a gas mixer. A controller regulates the amounts of incoming HHO gas and the natural gas through being mixed. The mixed gas is supplied to each burner assembly with a predetermined pressure and flowrate to generate a flame for the total combustion of the exhaust stream inside the exhaust pipe. With feedback from an exhaust measuring system inside the exhaust pipe adjacent the outlet, the controller can adjust the burner system for optimal operations and achieve total combustion. Thus, by passing the exhaust or gases through a substantial cross-section covered by each flame, emissions can be greatly reduced or eliminated.

An innovative oxyhydrogen (HHO) burner system including one or more burner systems is provided to eliminate emissions through total combustion. Each burner system includes at least one HHO gas supply and an external natural gas supply, both of which are connected to a gas mixer. A controller regulates the amounts of incoming HHO gas and the natural gas through being mixed. The mixed gas is supplied to each burner assembly with a predetermined pressure and flowrate to generate a flame for the total combustion of the exhaust stream inside the exhaust pipe. With feedback from an exhaust measuring system inside the exhaust pipe adjacent the outlet, the controller can adjust the burner system for optimal operations and achieve total combustion. Thus, by passing the exhaust or gases through a substantial cross-section covered by each flame, emissions can be greatly reduced or eliminated.

A premixing device for a water heater and the water heater having the same are provided. The premixing device for the water heater has a housing and a turning plate. A first airflow passage, a second airflow passage, a first gas passage and a second gas passage are formed in the housing. The turning plate is rotatably disposed on the housing to adjust an opening degree of the first gas passage and an opening degree of the first airflow passage. An air guide hole directly opposite to the first airflow passage is formed on the turning plate.

A premixing device for a water heater and the water heater having the same are provided. The premixing device for the water heater has a housing and a turning plate. A first airflow passage, a second airflow passage, a first gas passage and a second gas passage are formed in the housing. The turning plate is rotatably disposed on the housing to adjust an opening degree of the first gas passage and an opening degree of the first airflow passage. An air guide hole directly opposite to the first airflow passage is formed on the turning plate.