Abstract: A burner assembly including a housing having an air inlet and a burner end. An impeller that is mounted in the housing is in communication with the air inlet and adapted to direct air toward the burner end of the housing. The burner assembly also includes an inner air tube that is mounted in the burner end of the housing so as to define an inner combustion zone and an outer combustion zone.

Abstract: A combination burner for selectively firing oil, natural gas and liquid propane. A modular first section has primary and secondary air tubes coaxially arranged therein and communicates with the main combustion air supply fan. A modular section is joined by bolts or the like to the first section and into which the primary and secondary air tubes extend. A center air spin vane rack is upstream of the secondary air tube in the first section. An adjustable spin vane rack is located radially outwardly of the secondary air tube for selectively spinning the main combustion air for flame adjustability. An air diverter is provided at a downstream end of the primary air tube. A compressed air atomizer is also at the downstream end of the primary air tube.

Abstract: As electronic programmable valve positioning linkage for a burner used in a hot mix asphalt plant is associated with fuel, air and optionally flue gas recirculation valve motors. To avoid an undesired rich condition which might result in an explosive condition, the linkage employs a program logic which changes a valve position, depending on increase or decrease of the burner output, in response to a temperature controller and thereby maintain an acceptable lean condition. The air valve motor is controlled by the temperature controller when burner output is to be increased with the fuel valve motor following the air valve motor, and the fuel valve motor is controlled when the burner output is to be decreased with the air valve motor following the fuel valve motor. In conjunction with the linkage, a mass flow system can be provided to calculate fuel/air and/or flue gas recirculation ratios based upon measurement of air flow, fuel flow and flue gas flow.

Abstract: A combination burner which uses primary and secondary fuel injection and improves liquid propane combustion. The burner supplies primary air, while secondary air is swirled to shape and mix the flame when the burner is firing "on oil". When the burner is firing "on gas", primary air enters the burner through an annulus at the atomizing air pipe or conduit so as to have the primary gas enter that pipe; secondary gas is injected radially into the air stream at a downstream location relative to an atomizing nozzle. In using liquid propane (butane) to fire the burner, two stage fuel injection is used, with a stream of fuel being injected upstream and toward the burner centerline and another stream of fuel being injected downstream and outwardly away from the burner centerline.

Abstract: A burning method provides a versatile burner by promoting rapid mixing and a stable flame to reduce NO.sub.x and CO emissions over a wide operating range. The burner includes a primary fuel supply, a combustion air supply arranged to supply combustion air at low pressure, and a swirler for swirling the combustion air. When the primary fuel supply is gaseous fuel, the gaseous fuel is introduced axially into the swirling combustion air. Secondary gas nozzles are arranged at the exit of the burner to supply and mix boost gas for combustion with the combustion air when the gaseous fuel is the primary fuel supply. An atomizer is arranged for atomizing liquid fuel when the primary fuel supply is a liquid fuel.

Abstract: A burner and burner firing method and system for a furnace combustion chamber in which a burner, having an ignition chamber for discharging an ignited combustible mixture of primary air and fuel into the furnace combustion chamber, and a plurality of nozzle ports for directing a high velocity stream of secondary air into the furnace combustion chamber in a direction generally parallel to the direction of flow from said ignition chamber, is operated in a first mode at furnace combustion chamber temperatures up to a transitional temperature by accelerating a burning mixture of fuel and air to moderately high velocities into the furnace combustion chamber, and in a second mode at furnace combustion temperatures above said transitional temperature by introducing a relatively low velocity stream of fuel mixed with a minor amount of air needed for stoichiometric combustion and accelerating a separate stream of air to high velocities into the furnace combustion chamber for mixture with said low velocity stream downs

Abstract: A burning method promotes rapid mixing and a stable flame in a burner to reduce NO.sub.x and CO emissions and to provide a smoother, quieter operation. The burner includes a primary fuel supply, a combustion air supply arranged to supply combustion air at low pressure, and a swirler for swirling the combustion air. When the primary fuel supply is gaseous fuel, the gaseous fuel is introduced radially into the swirling combustion air. A bluff body cone is arranged near the exit of the burner so as to be encountered by at least the swirling combustion air. An atomizer is arranged within the bluff body cone for atomizing liquid fuel when the primary fuel supply is a liquid fuel. Boost gas nozzles are arranged toroidily at the exit of the burner to supply and mix swirling boost gas for combustion with the combustion air when the gaseous fuel is the primary fuel supply, and mixer tabs are disposed around the periphery of the exit.

Abstract: A draft control for material processing apparatus, such as asphalt plants, having a chamber through which material to be processed is passed for contact with combustion gases and heat originating in a fuel supplied burner which may require a draft to draw air into the chamber for complete combustion of burner supplied fuel and to exhaust the products of combustion and other gaseous materials from the chamber. The air pollutants and the percent oxygen in the exhausted gases are monitored, and the draft is adjusted between minimum and maximum values for a given burner set point when the air pollutant content of the stack gases exceeds a predetermined maximum limit. The direction of draft adjustment is determined by the percent oxygen in the exhaust gases.