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.

An outer peripheral edge part of the air-fuel mixture permeable member is connected to a portion away outward by a predetermined distance from an inner peripheral edge of the burner frame. Between the burner frame and the air-fuel mixture permeable member a clearance reaching the inner peripheral edge of the burner frame is secured at a position inward of the outer peripheral part of the air-fuel mixture permeable member. Preferably, a bent edge part formed on an inner peripheral edge of the burner frame, in a manner to be bent toward the air-fuel mixture permeable member. The amount of the air-fuel mixture to flow into the clearance is limited to a smaller amount.

A burner includes an oxidant feed passage, a fuel feed passage surrounding the oxidant feed passage, an air feed surrounding the fuel feed passage, a movable air flow diverter and, optionally, a flame nozzle. The movable air flow diverter and/or flame nozzle are independently configured to create one or a plurality of gas recirculation regions adjacent the downstream tip of the burner to improve the mixing and reaction of the fuel and oxidant, and overall combustion process efficiency. A related furnace and method for generating a stable flame with the burner are also provided.

A cylindrical burner apparatus and method which produce low noise levels and are not dependent upon a blower, or natural draft, for providing combustion air flow. A flow of combustion air is induced into a rearward end of a burner tube and a swirling flame is produced in the tube by discharging a gas fuel from a plurality of discharge ports located in the tube.

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. A flow of combustion air is induced into a cylindrical burner lube by discharging a gas fuel from a plurality of discharge ports located inside the rearward end of the tube. At least some of the discharge ports are oriented to direct jets of the gas fuel toward flame stabilization structures positioned downstream of the discharge ports.

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.

The present invention relates to a gas burner assembly (10), in particular for a gas cooking appliance, preferably for a domestic gas cooking hob. The present invention further relates to such a gas cooking appliance comprising at least one gas burner assembly (10). The gas burner assembly (10) comprises a burner head (12) including a plurality of high-power flame ports (32). The gas burner assembly (10) comprises at least one intermediate element (14, 16) including a plurality of low-power flame ports (38). The burner head (12) is arranged above the at least one intermediate element (14, 16). The high-power flame ports (32) are connected to a first gas inlet (30) via a horizontal Venturi pipe (22). The low-power flame ports (38) are connected to a second gas inlet (52) via an annular distribution chamber (46). The low-power flame ports (38) and the high-power flame ports (32) are located on different parts of the gas burner assembly (10) and arranged in super-imposed way. According to a first aspect of the invention, the gas burner assembly (10) comprises at least one base part (20) arranged beneath the at least one intermediate element (14, 16), wherein at least one low-power injector (18), at least one pre-mixing chamber (48) and preferably the second gas inlet (52) are integrated within said base part (20). According to a second aspect of the invention, the gas burner assembly (10) is arranged in the gas cooking appliance in that way that the primary fresh air for the high-power flame ports (32) is sucked from the bottom side and the primary fresh air for the low-power flame ports (38) is sucked from the top side of a work plate (54) of the gas cooking appliance.

A furnace includes a gas burner exposed to a heat-exchange tube. An inducer is fluidly coupled to the heat-exchange tube and configured to induce draft air through the heat-exchange tube. A regulator is fluidly coupled to the gas burner. A rollout shield is disposed adjacent to the gas burner. A rollout switch is disposed in the rollout shield. The rollout switch is electrically coupled to the regulator. At least one vent is formed through the rollout shield adjacent to the rollout switch. The vent provides a path for a rollout flame to the rollout switch. The at least one vent is disposed on at least two sides of the rollout switch.

A flame hole unit structure of a combustion apparatus provided with a plurality of flame holes for forming a flame comprises: a lean flame hole unit including, as a flame hole for jetting lean gas, at least one lean flame hole extending along the longitudinal direction which is a direction perpendicular to the jetting direction of the lean gas; and a rich flame hole unit including, as a flame hole for jetting rich gas, a pair of rich flame hole provided on both sides of the lean flame hole unit with respect to a width direction which is a direction perpendicular to the jetting direction and the longitudinal direction and extending along a direction parallel to the longitudinal direction. When a region, which is defined at the top end of the rich flame hole by means of first and second lines that are arbitrary imaginary lines across the rich flame hole, and by means of a pair of rich flame hole walls spaced apart along the width direction and forming a part of the rich flame hole between the first and second lines, is referred to as a reference region, then the rich flame hole includes a region which is designed such that, at the time of generating the flame by the rich gas, between arbitrary reference regions of the same size, the sum of the amounts of heat transferred to the pair of rich flame hole walls forming each reference region is substantially the same.

A solid fuel burner is provided with a guide member arranged on an outer circumferential section of a distal end of a first gas nozzle so as to guide a fluid flowing through a second flow passage outward in a radial direction; and a contraction forming member that is arranged on an upstream side of the guide member with respect to the flow direction of the second flow passage so as to reduce the cross sectional area of the second flow passage. An outer diameter of the guide member is formed to be smaller than an inner diameter of an outer peripheral wall of a second gas nozzle. The first gas nozzle, the guide member, and the contraction forming member are configured so as to be integrally attachable/detachable along an axial direction of the first gas nozzle toward the outside of a furnace.