Abstract: A combustion system includes a fuel distributor configured to output a fuel, an oxidant source configured to output an oxidant, and a mixing tube defining a mixing volume aligned to receive the fuel and oxidant. The mixing tube is shaped to convey the fuel and the oxidant through the mixing volume at a bulk velocity higher than a flame propagation speed. The combustion system includes a flame holder aligned to receive the mixed fuel and oxidant and to support a combustion reaction of the fuel and the oxidant.

Abstract: A burner comprises: at least one mixing tube extending inside a fuel plenum and having an interior configured to be supplied with an air; and a plurality of fuel injection holes for injecting a fuel supplied to the fuel plenum into the interior of the at least one mixing tube. When the at least one mixing tube is viewed in an axial direction of the mixing tube, a central axis of each of the plurality of fuel injection holes is oblique in a same direction with respect to a circumferential direction of the mixing tube, to a radial direction of the mixing tube.

Abstract: A gas burner for a household appliance includes a burner housing having a mixing chamber for mixing fuel gas with primary air, a gas nozzle accommodated in the burner housing and configured to inject the fuel gas into the mixing chamber, and an annular first primary air inlet provided between the gas nozzle and the mixing chamber for drawing in the primary air. The gas nozzle has a second primary air inlet which is guided through the nozzle for drawing in the primary air. The second primary air inlet is configured in a direction of flow of the primary air through the second primary air inlet to taper at least once and to widen out again. The gas nozzle has an annular fuel gas outlet opening which opens directly into the second primary air inlet.

Abstract: A fuel supply system for an aircraft engine, comprises a gaseous fuel source and a fuel nozzle. The fuel nozzle includes a housing having a housing interior chamber and a fuel swirler disposed inside the housing interior chamber. The fuel swirler is fluidly connected to the gaseous fuel source for directing gaseous fuel to a combustor of the aircraft engine. The fuel swirler defines a gaseous fuel path extending from a fuel inlet to a fuel outlet. The gaseous fuel path includes a plurality of discrete apertures distributed around a circumference of the fuel swirler, each of the plurality of discrete apertures having a cross-sectional area selected to prevent a flame from propagating in an upstream direction through the gaseous fuel path towards the gaseous fuel source.

Abstract: A burner assembly includes a spreader, a burner base, and at least one annular burner cap. The spreader has a bottom and a combustion chamber that is defined by a crenellated wall wherein a plurality of fuel exit portions defines the crenellated wall. The burner base includes a peripheral wall. The at least one annular burner cap is coupled to the peripheral wall of the burner base and is positioned on the crenellated wall.

Abstract: Cooking apparatus for cooking food by a barbecue grilling method, comprises an outer housing receiving an inner housing which defines a heating volume. A chamber for pressurised air is defined between the outer and inner housings. Apertures in the inner housing allow pressurised air to exit the chamber into the heating volume. At least one burner is located in the inner housing. A combustible fuel/air mixture is supplied to the burner and this is separate from the supply of pressurised air to the chamber. A cooking surface is placed across the top of the heating volume to support food to be cooked.

Abstract: A gas burner includes a base with a first body and a raised annular band on an upper surface of the first body. A flange is formed about an outer periphery of the first body wherein the raised annular band and the flange define a first annular recess therebetween. A first notch is formed in a lower surface of the first body and extends through the flange and communicates with the first annular recess. The first notch is adapted to accommodate spark ignitor therein. A slot is formed in the raised annular band. A first cap includes a peripheral side wall having a distal end dimensioned to be received within the first annular recess. A gap between the distal end and a bottom wall of the first annular recess when the first cap is received therein provides fluid communication between the slot and the first notch.

Abstract: Improved orthodontic appliances, along with related systems and methods, are provided. In one aspect, an appliance includes a shell having a plurality of cavities shaped to receive teeth, and a discontinuity formed in the shell. The appliance also includes an elastic member having a first portion directly coupled to the shell at a first attachment point and a second portion directly coupled to the shell at a second attachment point. The elastic member can be positioned to interact with the discontinuity.

Abstract: The present disclosure provides a nozzle structure for a hydrogen gas burner apparatus, capable of reducing an amount of generated NOx. A nozzle structure for a hydrogen gas burner apparatus, includes an outer pipe, an inner pipe disposed concentrically with the outer pipe, and a stabilizer configured to throttle a space between the outer pipe and the inner pipe. The inner pipe includes an inner pipe end part with an axial opening hole and a circumferential opening hole formed therein, the axial opening hole penetrating in an axial direction of the inner pipe, the circumferential opening hole penetrating in a radial direction of the inner pipe. A hydrogen gas flows through the inner pipe. The circumferential opening hole lets the hydrogen gas flow out from the inner pipe in the radial direction of the inner pipe.

Abstract: A vacuum pump with abatement function is used for evacuating a chamber of a manufacturing apparatus. The vacuum pump with abatement function includes a vacuum pump having a discharge port to which one or more abatement parts for treating an exhaust gas discharged from the vacuum pump to make the exhaust gas harmless are attached. The one or more abatement parts are selected, depending on the amount and kind of the exhaust gas discharged from the vacuum pump, from plural kinds of abatement parts which have different treatment types of exhaust gas and/or different treatment amounts of exhaust gas.

Abstract: The present invention relates generally to the field of emission control equipment for boilers, heaters, kilns, or other flue gas-, or combustion gas-, generating devices (e.g., those located at power plants, processing plants, etc.) and, in particular to a new and useful method and apparatus for reducing and/or eliminating various liquid discharges from one or more emission control equipment devices (e.g., one or more wet flue gas desulfurization (WFGD) units). In another embodiment, the method and apparatus of the present invention is designed to reduce and/or eliminate the amount of liquid waste that is discharged from a WFGD unit by subjecting the WFGD liquid waste to one or more drying processes, one or more spray dryer (or spray dry) absorber processes, and/or one or more spray dryer (or spray dry) evaporation processes.

Abstract: A burner case and a burner device provided with the burner case are disclosed. A cover for closing an opening of a case body of the burner case is attached to the case body by a first caulking portion and a second caulking portion. A first caulking direction and a second caulking direction intersect with each other, the first caulking direction is a direction in which a first attachment piece and a first facing portion, those constituting the first caulking portion, face each other and are caulked, the second caulking direction is a direction in which a second attachment piece and a second facing portion, those constituting the second caulking portion, face each other and are caulked. Thus, the case body and the cover are not required to be screwed or the number of the screws is reduced, and leakage of gas from the burner case to outside is prevented.

Abstract: A gas burner apparatus and a cooking apparatus including the same are provided. The gas burner apparatus a first burner, a second burner spaced apart from a lower side of the first burner, a support plate on which the second burner is disposed, and a secondary air supply flow channel to supply secondary air to the first burner, the secondary air supply flow channel including a first secondary air supply flow path formed between the first and second burners and a second secondary air supply flow path starting from an area lower than the support plate, the first and second paths being connected to each other.

Abstract: A burner assembly including a gas inlet fixture for use with a burner tube, the gas inlet fixture including a plurality of tabs to engage a neck of a gas control valve to improve ignition and center the gas flow down the center of the burner tube.

Abstract: A method of providing fuel to a combustion chamber of a combustion can in a radial direction of the combustion can, and a micromixer cap having axially arranged fuel stages that receive fuel from a radial direction, the fuel stages supplies fuel to different radial zones of micromixer tubes arranged in a concentric configuration to provide a mixture of fuel and air for combustion.

Abstract: A flow device for an exhaust system includes a body that defines an interior cavity. An exhaust inlet passage is disposed in the interior cavity. An exhaust outlet passage is disposed in the interior cavity so that at least a portion of the exhaust inlet passage circumferentially surrounds at least a portion of the exhaust outlet passage. A doser is adapted to inject reductants into the interior cavity of the body such that the reductants are injected in the same general direction as the direction of flow of the exhaust gases.

Abstract: A tubular burner includes: a mixing tube having an inlet port into which a fuel gas and primary air flow; and a flame hole member having a plurality of flame holes and being fitted into a front end portion of the mixing tube. The flame holes of the flame hole member are made up of a central main flame hole and a plurality of subsidiary flame holes positioned around, and each being smaller than, the central main flame hole. In an annular region of the flame hole member defined between an outer periphery of the flame hole member and the central main flame hole, a plurality of non-flame-hole regions which are free from formation of the subsidiary flame holes are provided at a circumferential distance from one another. The plurality of the subsidiary flame holes are formed in each of flame hole regions defined between the non-flame-hole regions.

Abstract: A selector valve and shutter mechanism for use with a gas burner unit is disclosed. The valve includes a pilot gas manifold which is in communication with two pilot flames and associated ODS for two different kinds of gas fuel. The shutter mechanism opens or closes an opening to a burner mixing chamber to thereby adjust the flow of air into the mixing chamber depending on the fuel selected, and preferably is in the form of a sleeve that in one approach is rotatably mounted on a part of the burner mixing chamber, with a part of the sleeve covering the mixing chamber opening in one orientation and opening it to airflow in another orientation. A first gear is mounted on the sleeve which is engageable with a second gear mounted on part of the valve which is rotatable to one position or another depending on the gas fuel selected, the sleeve thereby adjusting the airflow to the mixing chamber in response to the valve position. In another approach, the cover moves linearly along the burner tube between orientations.

Abstract: A gas stove having an upper work plate with at least one integrated gas burner, said gas burner including a bowl-shaped base body, a burner crown, and an upper cap, with several flame ports provided to let out a gas-air mixture towards a recipient to be heated, and an annular mixing zone, whose cross section incrementally expands towards the flame ports, defined between the burner crown and the upper cap with the burner crown including a Venturi pipe which feeds the gas-air mixture into the mixing zone and is designed to suck primary air from above the upper work plate the flame ports are formed in the upper cap as through-holes, and the bottom side of the upper cap, which defines the upper side of the mixing zone, is at least partially inclined upwardly towards the flame ports to define the incrementally expanding cross section of the mixing zone.

Abstract: A furnace for performing an endothermic process comprises tubes containing a catalyst for converting a gaseous feed, said tubes positioned inside the furnace, inner burners mounted to a furnace roof between the tubes, and outer burners mounted to the furnace roof between the tubes and a furnace wall. The outer burners are positioned close to the furnace wall, and configured to operate with 45-60% of the power of the inner burners and with an inlet velocity between 90 to 110% of the inlet velocity of the inner burners.

Abstract: Provided is a burner. The burner includes a burner body receiving a gas and air, a burner head seated on the burner body, the burner head including an inner burner head and an outer burner head, and a burner cap seated on the burner body to cover the burner head. An outer flame hole through which a mixture gas is discharged and a flame spread space for spreading flame into the inner burner head are defined on the outer burner head, and an inner flame hole through which the mixture gas is discharged and an ignition hole defined under the inner flame hole are defined on the inner burner head.

Abstract: A tubular burner includes a mixing tube and a flame hole member having a plurality of flame holes. The flame hole member is made of a sheet metal plate and has: a circular disk part having the plurality of flame holes formed therein; and a fitting tubular member which is elongated backward from a periphery of the circular disk part and is adapted to be fitted into an inner circumference at the front end region of the mixing tube. A clearance-generating section is formed at a front of the fitting tubular member so as to generate an annular clearance between the clearance-generating section and the inner circumference at the front end region of the mixing tube. A plurality of flame retention holes are formed in the clearance-generating section at a circumferential distance from one another.

Abstract: The present invention relates to a gas combustor, comprising: a gas intake valve, the bottom of a valve tube axially formed in a valve member is installed with a filter member, a first spring is installed above the filter member and inside the valve tube, the top of a valve pin is protruded out of a tube opening formed at and communicated with the top of the valve tube, a plug outwardly protruded at the bottom of the valve pin is abutted against the first spring, the plug is enabled to seal the tube opening through the first spring being stretched, and when the top of the valve pin is axially subject to a force, the valve pin and the plug are downwardly moved, the first spring is compressed thereby enabling the tube opening to be opened.

Abstract: A burner cap and a burner are provided. The burner cap may include a cap body, an opening formed in the cap body, at a location separated from an edge of the cap body, proximate the center of the cap body, a distribution protrusion formed on a bottom part of the cap body, and a connection guide formed on the distribution protrusion.

Abstract: A premix burner is provided for a gas turbine, in the form of a double-cone burner, which has two partial cone shells which are arranged nested one inside the other, forming air inlet ducts between them, through which combustion air from the outside flows into a conical inner space of the premix burner. Linear rows of holes of injection openings, which extend transversely to the flow direction of the combustion air, are arranged on the outer walls of the air inlet ducts and through which a gaseous fuel is injected into the combustion air which flows past transversely to them. A method for reworking such premix burners is also provided.

Abstract: A gas burner has an air-gas mixture distribution section with an open loop geometry and a plurality of sides. The air-gas mixture distribution section has a top heating surface and a plurality of ports are disposed on the top heating surface. An inlet is disposed on one of the plurality of sides of the air-gas mixture distribution section and a distribution diffuser is mounted inside the air-gas mixture distribution section.

Abstract: Gas burner, preferably for domestic use, of the type comprising at least one fuel gas injector and at least one corresponding Venturi effect mixer, wherein the above-mentioned injector faces the intake section of said Venturi effect mixer, and one or more passages for the transit of primary air from above the supporting surface, to which the burner is fixed, to the intake section of the Venturi effect mixer. The burner is also provided with means for preventing flame propagation, of the fluid flow splitting type, which comprises at least one substantially tubular body, with relative lateral walls extending at least between the injector and the intake section of the Venturi effect mixer, advantageously consisting of at least one helically wound filiform element.

Abstract: A method and an apparatus are provided for the combustion of gaseous fuel containing hydrogen or consisting of hydrogen, with a burner which provides a swirl generator, into which liquid fuel is fed centrally along a burner axis, at the same time forming a conically shaped liquid fuel column which is surrounded by a rotating combustion air stream which flows tangentially into the swirl generator and into which, additionally, a gaseous and/or liquid fuel is injected so as to form a fuel/air swirl flow which is transferred downstream of the swirl generator, along a transitional portion, into a mixing zone following the transitional portion downstream and which is ignited and burnt in a combustion chamber following downstream, at the same time forming a backflow zone.

Abstract: In a rich-lean burner, a gap formed between a lean-flame port and a rich-flame port is in fluid communication with a supply passage through which a lean gas is to be supplied to the lean-flame port. One or more projections are provided on at least one of partition plates disposed between the gap and the lean-flame port and between the gap and the rich-flame port. A recessed portion is formed at a region adjacent to the lean-flame ports at an interface between the distal end of at least one of the projections protruding from one of the partition plates and the other of the partition plates, the distal end of the at least one of the projections being partially not in contact with the other of the partition plates to provide a clearance through which the lean gas is allowed to be supplied to the gap.

Abstract: A gas burner for household may include a zone for mixing combustible gas with air to form an air-gas mixture, an inner chamber with an inner table, and including sides with crenellated walls. A vertex may be formed on each end of the sides, which may be formed by intersecting curved surfaces. A port zone may be on an upper face of the crenellated walls. The port zone includes main ports, which may be centric relative to the vertexes. The symmetry axes of the main ports may be aligned towards the vertex closest to a corresponding port. The ports may be equidistant relative to one another. A lid may close the inner chamber and pass the mixture through the ports. The curved surfaces may have different geometries. The lid may include a cavity, where another burner may be placed.

Abstract: A lean-rich burner is provided, in which an air-rich flame and a fuel-rich flame are formed by a simple structure, thereby reducing the emission of noxious gas and enabling stable combustion. The lean-rich burner includes: a main flame part (110) for burning a fuel-rich mixture in which primary air, which is some of air supplied by a blower, and fuel are mixed; auxiliary flame parts (120) installed on left and right sides of the main flame part (110) to burn an air-rich mixture; a main mixture channel (130) for supplying the fuel-rich mixture to the main flame part (110); a mixture distribution hole (140) formed along the main mixture channel (130) to supply some of the mixture flowing along the main mixture channel (130) to the auxiliary flame parts (120); and a Venturi part (150) having a Venturi structure in which secondary air inflow holes (151) are formed to mix secondary air, which is some of the air supplied by the blower, with the mixture introduced through the mixture distribution hole (140).

Abstract: In various implementations, a burner assembly may include a body coupled to burner heads. The body may include one or more converging and/or diverging parts. For example, the body may include a diverging part proximate one or more of the burner heads of the burner assembly. The body may allow a predetermined fuel/air ratio to be provided to the burner head, in some implementations.

Abstract: The burner preferably exclusively burns substantially explosible solid fuels and preferably has instant ON-OFF thermostat control, wastes no energy preheating the enclosure or external air supply, achieves stable combustion the moment the powder-air mix is ignited in our burner, is used in the upward vertical mode except for oil burner retrofits, burns a solid fuel in a single-phase regime as if it were a vaporized liquid or gas, is designed to complete combustion within the burner housing itself rather than in a large, high temperature furnace enclosure which it feeds, has an ultra-short residence time requirement, is a recycle consuming burner with self-contained management of initially unburned particles, is much smaller, simpler and lower cost, has a wider dynamic range/turndown ratio, is more efficient in combustion completeness and thermal efficiency, and operates with air-fuel mix approximately at the flame speed.

Abstract: The present invention relates to a gas burner in which a burner body and a side plate are assembled together without a welding process, to thereby simplify manufacturing procedures and reduce manufacturing costs. To accomplish this, the gas burner of the present invention includes a plurality of burner units (110), each of which has a burner body (111) with a main flame being formed at the top thereof, a side plate (112) which forms auxiliary flame holes (116) in the spaces between both side surfaces of the burner body (111) and the side plate (112), and a plurality of supports (113, 114) protruding from the side plate (112). Both ends of each of the burner units (110) are supported by first and second brackets (200a, 200b), respectively. The supports (113, 114) formed at the side plate (112) of the burner unit are brought into contact with and are supported by supports (123, 124) formed at a side plate (122) of an adjacent burner unit (120).

Abstract: A burner assembly for and method of producing ethylene having a mechanism to inject either primary fuel, staged fuel, or both by premix methods before combustion in a furnace. The burner assembly has at least one premix injection assembly for either exclusively primary fuel or exclusively staged fuel injection paired with a nozzle mix injection or injection means for primary and staged fuel both by premix methods. The primary fuel premix assembly associates with a burner tile that consists of multiple inlets and outlets connected by venturi channels to direct and combine combustion air and staged fuel coming from staged fuel orifice spuds. Primary fuel and combustion air are mixed in a premix assembly and directed inside the furnace, and above the burner tile to complete the reaction with the staged fuel and combustion air mixture in a combustion zone inside of the furnace.

Abstract: In various implementations, a burner may include two venturi inlets coupled to one or more burner heads. The venturi inlets may be opposingly disposed. During use, fuel may be provided to the burner via the two venturi inlets and at least partially combusted proximate the burner heads.

Abstract: The present invention relates to a residual gas burner (13) for a fuel cell system (1) having to educt gas feeds (11, 12) for feeding an educt gas each to a combustion chamber (14) of the residual gas burner (13). An improved operation of the residual gas burner (13) is obtained when the educt gas feeds (11, 12) each comprise outlet openings (22, 27), wherein the outlet openings (22, 27) face the combustion chamber (14) and the outlet openings (22, 27) of one of the educt gas feeds (11, 12) face a first bottom surface (29) of the other educt gas feed (11, 12). In addition, the invention relates to a fuel cell system (1) having such a residual gas burner (13).

Abstract: An apparatus includes a gas burner assembly which includes a gas burner and a gas supply conduit. The gas burner includes a gas supply opening and a substantially cylindrical socket formed on the exterior of the gas burner around the gas supply opening. The gas supply conduit includes an opening at an end and a substantially tubular adjoining section proximate to the opening. The adjoining section is configured to mate with the socket and includes a substantially radial protrusion. The socket includes a substantially radial depression for receiving the protrusion. As the gas supply conduit is connected with the gas burner to establish fluid communication at the gas supply opening, the protrusion is engaged in the depression thereby aligning the adjoining section in a predetermined manner about the socket and restricting rotational movement of the adjoining section about the socket.

Abstract: The finding concerns a multi-gas burner head with sucked or blown air, from which the mixture of fuel gas and comburent air comes out and the combustion occurs. Such a head is made from a metallic sheet in which there is at least one row of aligned slits (2), substantially rectangular-shaped; such a sheet is folded so as to have a series of flat flaps (3) in succession, each of the slits being arranged so as to be closed like a “sandwich” between two flat portions of the sheet, once the flaps of the structure are mutually compressed. The gas mixture is intended to pass from the bottom (5) of the flaps and then through the slits and finally to come out at two side by side crests (6) of the structure where the combustion occurs.

Abstract: A premix burner arrangement for safely oxygen-enriching a premix air-fuel combustion system is disclosed. In the disclosed burner arrangement, a first conduit is arranged and disposed to provide a first gas stream. The first gas stream is a self-reactive or self-flammable premixture comprising air and a combustible gas. At least one second conduit is arranged and disposed to provide a second gas stream circumferentially around the first gas stream. The second gas stream includes oxygen. The premix burner arrangement is configured to combust or react the first stream at a temperature at least 1000° F. greater than the temperature of the second stream. A method and combustion system including the premix burner arrangement are also disclosed.

Abstract: A gas burner, which is particularly suitable for flame treatment of substrates having large surfaces, e.g. for coating such surfaces in a combustion chemical vapor deposition (CCVD) process, includes a burner body with a gas supply connection and a nozzle plate, wherein the burner body and the nozzle plate constitute together a gas plenum and the nozzle plate constitutes a perforated wall section of the plenum. The nozzle plate includes a large number of nozzles extending from a plenum side to a flame side of the nozzle plate and it is made of a plurality of sheets which are arranged in a stack and extend substantially perpendicular or substantially parallel to the nozzle extension. The sheets include through openings, wherein the through openings of all sheets are at least partly aligned with each other, or they have a comb-like form.

Abstract: A burner insert for use with a burner is provided. The burner insert includes a cylindrical body member having an inlet end and an outlet end. The cylindrical body includes a central passage and a plurality of openings disposed about the central passage. One or more fins are axially disposed within the central passage. A plurality of rib members are coupled to the body, each of the plurality of rib members axially disposed within one of the plurality of openings.

Abstract: A fuel-fired furnace incorporates specially designed fuel/air mixing and combustion structures. The fuel/air mixing structure is of a mixing sound-attenuating design and comprises a venturi having a perforated sidewall portion and being surrounded by a noise-damping housing chamber communicating with the interior of the venturi via its sidewall perforations. During use of the mixing structure, air is flowed through the venturi in a swirling pattern while fuel is transversely injected internally against the swirling air. The combustion structure comprises a burner box housing into which the fuel/air mixture is flowed, combusted, and then discharged as hot combustion gas into and through the heat exchanger tubes. The fuel/air mixture entering the burner box housing initially passes through a non-uniformly perforated diffuser plate functioning to substantially alter in a predetermined manner the relative combustion gas flow rates through the heat exchanger tubes.

Abstract: The invention relates to a streamlined body for influencing the flow dynamics of a fluid, wherein the streamlined body at least partly corresponds to a rotationally symmetrical airfoil. A streamlined body of this kind can be used in a number of ways, for example as an impact member, as a flow regulator or as a heat exchanger. It also evens out and accelerates flows. It is used to particular advantage in a mixing and reaction chamber for burning fuels.

Abstract: A burner has a fuel/oxidant nozzles and a pair of dynamical lances spaced on either side thereof that inject a jet of fuel and primary oxidant along a fuel injection axis, and jets of secondary oxidant, respectively. Jets of actuating fluid impinge against the jets of secondary oxidant to fluidically angle the jets of secondary oxidant away from the fuel injection axis. The action of the angling away together with staging of the oxidant between primary and secondary oxidant injections allows achievement of distributed combustion conditions.

Abstract: A gaseous fuel-oxygen burner is described herein. One device includes a flame zone in which combustion of gaseous fuel and oxygen occurs to form a flame, a coaxial gaseous fuel jet configured to provide the flame zone with gaseous fuel, and a coaxial oxygen jet configured to provide the flame zone with oxygen, wherein the coaxial gaseous fuel jet and the coaxial oxygen jet are separate such that the gaseous fuel from the coaxial gaseous fuel jet and the oxygen from the coaxial oxygen jet do not mix before entering the flame zone.

Abstract: A natural draft combustion mixer in which the primary air intake is positioned downstream from the point of fuel introduction and also consists of a heat return port for orifice freeze protection that is located adjacent to the orifice, as well as a removable orifice holder for ease of access to the orifice during maintenance and set-up of a combustion system.

Abstract: The present invention relates to a method for operating combustion process in a furnace whereby a primary fuel and a secondary fuel are burnt, to an apparatus for injecting liquid oxygen into the furnace and also to the corresponding furnace. The method comprises at least the following steps: the primary fuel and a primary oxidizer are injected into the furnace to create a primary combustion zone, liquid oxygen is injected in as secondary oxidizer such that the secondary fuel combusts with the secondary oxidizer thereby creating a distinct secondary combustion zone. The invention makes it possible for a secondary fuel having a significantly lower calorific value than the primary fuel to be burnt completely in the furnace, such that a product to be produced in the furnace has an improved quality.

Abstract: A dual venturi having a tubular part having primary and secondary passageways, wherein a primary gas inlet is provided on the side wall of the primary passageway; a body part, for opening/closing the flow of secondary air by rotating in horizontal plane and vertical plane directions, the horizontal plane direction being the cross-sectional direction of the tubular part and the vertical plane direction being perpendicular to the horizontal plane; a damper part having a damper part-side secondary gas outlet; a driving part, for rotationally driving the damper part in the horizontal and vertical planes; and a secondary gas inlet, which openly connects selectively to the damper part-side secondary gas outlet on the basis of the rotational position of the damper part, and for forming the rotational shaft of the damper part along with the rotational shaft of the driving part.

Abstract: Provided is a dual venturi having: a tubular part; a body part, for opening/closing the flow of secondary air by rotating in the horizontal plane and vertical plane directions, the horizontal plane direction being the cross-sectional direction of the tubular part and the vertical plane direction being perpendicular to the horizontal plane; a central passageway, becoming the passageway for primary air; a damper part, and a damper part-side secondary gas outlet; a driving part, for rotationally driving the damper part in the horizontal and vertical planes; a gas inlet-side primary gas outlet connected openly to the damper part-side primary gas outlet; and a gas inlet for introducing gas into the tubular part via the damper part, which openly connects selectively to the damper part-side secondary gas outlet on the basis of the rotational position of the damper part, and for forming the rotational shaft of the damper part along with the rotational shaft of the driving part.