KR20020092789A - Venturi cluster, and burners and methods employing such cluster - Google Patents

Abstract

PURPOSE: A venturi cluster, a burner, and a method for using the cluster are provided to reduce the discharge of nitrogen oxide by flowing fluid in parallel by installing the venturi cluster having a plurality of venturi tubes and to generate stable flames by considerably reducing the speed of fuel mixture. CONSTITUTION: A burner assembly(20) having a venturi cluster(30) having a plurality of venturi tubes(32) is composed of a multiple venturi assembly using pressurized fuel, as a guiding fluid induces air, supplying very thin-premixed fuel composed of fuel and air, a center burner tube installed with a nozzle with decreasing the speed of the premixed fuel by expanding the fuel not to make the linear speed of the fuel exceed the speed of the flame of the mixture before the fuel reaches the nozzle provided at a separated place, and a deflector arranged adjacent to the nozzle with assisting the stabilization of the flames after the expanding and decelerating process ends.

Description

Venturi cluster, and burners and methods employing such cluster}

The present invention relates to a venturi tube that induces a flow of a fluid when the induced flow of another fluid passes through the venturi tube. The invention further relates to burners using industrial burners and in particular venturi tubes which induce a flow of a mixture of one or more substances which are combustible to produce such a mixture for injection into the combustion zone. The invention also relates to a burner apparatus capable of making and adjusting an oxygen rich combustible mixture.

Venturi tube devices are known which direct the flow of one fluid (derived fluid) into the flow of another fluid (derived fluid). These devices consist entirely of tubes with inlet and neck and outlet ends. In general, the neck has a smaller flow zone than the injection stage to provide a low pressure zone in the neck. Induced fluid flows from the inlet end of the venturi tube through the tube to the outlet end, and the induced fluid source is in fluid communication with the low pressure region created in the wood apparatus by the flow of induced fluid. Therefore, the induced fluid is sucked into the neck and mixed with the induced fluid.

Venturi tube devices are particularly useful in burners where the flow of fluid fuel induces the flow of air to produce a mixture of fuel and air in the venturi tube. On the other hand, combustion air is usefully used to induce the flow of fuel. Alternatively, the flow of air or fuel through the venturi tube causes the flow of recycle flue gas or other diluents to control the flame temperature, thus affecting the production of nitrogen oxides.

Despite its universal use, Venturi tubes still have some limitations. First, the capacity of the venturi tube to direct the flow of induced fluid is limited by the usable pressure of the guide fluid and the quality of the guide fluid required for a given application. Moreover, typically the length of an efficient venturi tube is directly related to the diameter of the neck. Therefore, the physical size of the working environment has a limited effect on the venturi tube's capacity.

More generally, the reduction and alleviation of nitrogen oxides in industrial burners has always been considered a desirable purpose. Some reduction of nitrogen oxides has been achieved in the past by stepping through a portion of the gaseous fuel, using the combined fuel-lean combustible fuel and air mixture. Fuel-lean main mixtures are potentially desirable in some applications because excess air is provided to lower the flame temperature to reduce nitrogen oxides. The stepped gas is injected into the combustion zone from a gas tip arranged around the circumference of the burner or from a central gas tip protruding through the center of the downstream end of the burner nozzle. The second fuel is burned with excess air in an environment where flue gas is used as the diluent. Such assemblies have not always been successful in reducing nitrogen oxide emissions to the desired level.

In some cases, the lean fuel mixture is injected into the combustion zone at relatively high speed due to the excess mass supplied to the excess air. Often these speeds are higher than the flame speed to provide an unstable flame environment.

According to the principles and concepts of the present invention, an important aspect is to provide a composite venturi tube structure having a venturi tube cluster composed of a plurality of venturi tubes. Therefore, according to this aspect of the present invention clearly, the composite venturi tube structure has at least two venturi tubes. Preferably, the structure has at least three, often at least six venturi tubes, and in some cases even six or more venturi tubes, depending on the urgent circumstances of the particular application. An important object of the present invention is to substantially solve the problems currently provided in the field of burners, in particular caused by excess levels of nitrogen oxides. Therefore, the present invention proposes a structure and methodology that solves and alleviates the aforementioned problems. Moreover, the present invention generally solves the problems associated with venturi tubes. Because of the increased surface area provided by the multiple venturi tubes, the volume of a given inducing fluid leads to a greater flow of induced material. Moreover, with a given flow of induction fluid, the neck of the venturi tube bundle has a narrower neck, so that the length is smaller.

Each venturi tube of the cluster has an inlet, a neck and an outlet, and each venturi tube is adapted and arranged to cause the flow of the induced material through the path of the guided fluid through it. This action in each venturi tube creates a mixture of each induced material and induction fluid, with the mixture exiting the outlet of each venturi tube. The structure also preferably includes a collector having an injection stage connected and arranged in fluid communication with the outlet of the venturi tube. Therefore, the mixture of each induction fluid and induced material discharged from the discharge port is discharged from the discharge end of the aggregator and collected and mixed so that a single mixing flow exists. Most derived materials are fluids, but according to the broad aspects and contemplation of the present invention, the derived materials are fluid, eg solids such as powder or flakes.

The venturi tube of the composite venturi tube structure of the present invention is not necessarily required, but is preferably in the form of a long, essentially straight tube. The tubes do not necessarily need to be arranged but are preferably arranged essentially parallel to one another. In addition, venturi tubes have essentially the same physical capacity, which is also not essential or critical of the present invention, and in practice, many applications that are desirable for at least one venturi tube of a given cluster are related to the capacity of venturi tubes of the same cluster. Have different physical capacities.

In another important aspect of the invention, the composite venturi tube structure is a constituent member of the new burner assembly. According to this aspect of the invention, in addition to the venturi tube cluster and the collector, the burner assembly has a burner tip mounted to the discharge end of the collector to communicate fluid. Therefore, the tip is arranged to receive a single mixed flow of fluid from the collector and to direct the single mixed flow of fluid into the combustion zone.

In one important embodiment of the present invention, the tip is elongated and adapted to direct the single mixed flow out of the tip and into the combustion zone in the radial direction as a whole with respect to the longitudinal axis of the tip. Preferably this tip is adapted to create a round and flat flame around the tip.

In another important embodiment of the invention, the tip is elongated and adapted to direct the direction of a single mixing flow out of the tip and into the combustion zone generally axially relative to the longitudinal axis of the tip. Preferably this tip is adapted to produce a cylindrical flame extending along the axis.

Generally, the gaseous fuel or air is an induction fluid, but preferably at least one venturi tube is adapted and arranged to operate with the gaseous fuel as the induction fluid. If gaseous fuel is used as the induction fluid, air or recycled flue gas is the induced fluid. Preferably, the at least one venturi tube is adapted and arranged to operate with air as an induced fluid. Therefore, when gaseous fuel is used as the induction fluid and air is used as the induced fluid, the single mixed flow produced in the collector consists of a mixture of fluid fuel and air. Similarly, when gaseous fuel is used as the induction fluid and recycled flue gas is used as the induced fluid, the single mixture flow consists of a mixture of fluid fuel and flue gas. In some applications, gaseous fuel is used as the induction fluid to induce the flow of air in one venturi tube of a given cluster and the flow of flue gas in another venturi tube of the cluster. Therefore, this single mixture flow consists of a mixture of fluid fuel, air and recycled flue gas. One or more venturi tubes of the cluster are adapted and arranged to operate by diluent with induced fluid, such that a single mixture flow consists of fluid fuel and diluent. Diluents are steam, nitrogen, carbon dioxide, or other usable gas that is inert to the combustion process.

According to an important aspect of the invention, the collector is preferably arranged elongated to have a central axis extending between its ends. Preferably, the assembly has a central fuel tube extending through the collector along the central axis. Ideally, the central fuel tube extends through the burner tip, which has a downstream end projecting through an opening centrally located at the downstream end of the burner tip. According to a preferred aspect of the invention, the assembly has a fuel nozzle located at a downstream end of the central fuel tube.

Ideally, the injection end of the collector comprises an opening member for each venturi tube of the cluster, and the outlet of the venturi tube is connected to each opening member. The openings are arranged to extend in series around the central fuel tube so that the mixing flow is evenly distributed around the interior of the collector. If the tip is adapted and arranged to direct a single mixed flow out of the tip and into the combustion zone in a radial direction as a whole relative to the longitudinal axis of the tip, the fuel nozzle preferably provides a second fuel to the combustion zone. Is converted and arranged to be. On the other hand, if the tip is adapted and arranged to direct a single mixing flow out of the tip and into the combustion zone generally axially with respect to the longitudinal axis of the tip, the fuel nozzle is preferably axially at the downstream end of the tip. It is adapted and arranged to provide a continuous coin flame at a location within the spaced area. Ideally, in the latter case, the fuel nozzles should be located at a sufficient distance from the downstream end of the tip of the combustion zone, allowing the single-mix flow to expand and decelerate at a rate no closer than the flame holding speed when adjacent to the fuel nozzles. Is located.

In another aspect, the present invention provides a burner assembly consisting of, but not necessarily, a burner tube assembly having one or more venturi tube tubes. However, the burner tube assembly has a long and long burner conduit with spaced inlet and outlet ends. This conduit is a Venturi tube. Alternatively, it is simply a hollow tube or pipe member. The conduit is adapted and arranged as a whole to direct the combustible gas mixture consisting of fluid fuel, preferably in the form of gaseous fuel, and oxygen, preferably in the form of air, along the outlet from the inlet. According to an aspect of the invention, the burner tip is provided at the outlet end of the conduit, preferably such burner tip has a downstream end spaced from the outlet end of the conduit and the central axis. The tip as a whole is adapted and arranged to receive the combustible mixture from the conduit and to orient the combustible mixture into the combustion zone in a direction along the axis of the tip as a whole through one or more holes downstream of the tip.

In addition, the assembly according to this aspect of the present invention includes an elongated central fuel tube that passes through the tip and extends along an axis. The fuel tube preferably projects out of the tip axially through the downstream end of the tip, the fuel tube having a downstream end located in the combustion zone spaced apart from the downstream end of the burner tip. At the downstream end of the tip, a hole is arranged around the fuel tube so that the mixture directed into the combustion zone is cylindrical in shape, which entirely surrounds the fuel tube and extends outwardly of the downstream end of the tip along an axis towards the downstream end of the fuel tube. . Ideally, the assembly should have a fuel nozzle at the downstream end of the fuel tube, located at a point in the zone sufficiently far from the downstream end of the burner tip, so that after leaving the downstream end of the tip, the mixture expands and comes close to the fuel nozzle. Slow down to slower than flame speed. In this form of the invention, the burner assembly is preferably used with the combustible mixture consisting of a very fuel lean mixture of fuel and air.

Further in accordance with the concepts and principles of the present invention, a burner tip having a hemispherical shape as a whole is provided. The new burner tip of the present invention preferably has a generally annular base having a central axis and a plurality of elongated and parallel circumferentially spaced ribs extending in a direction along the axis. . The rib has a first end mounted at the base and a second end spaced from the base, the second end being located closer to the axis than the first end. The base and rib together define an area inside the tip that is adapted to accommodate the flow of a mixture of air and fluid fuel, with ribs only having two vectors extending along two radial directions and axes from the area inside the tip. Outside the burner tip in a direction defining a plurality of curved slots that allow the mixture to flow into the combustion zone from the outside. According to the invention, the burner tip has a crown portion connected to the second end of the rib, the crown portion having discontinuities aligned with the respective slots extending in a plurality of axial and radial directions, thereby discontinuing the portion. The mixture of air and fluid fuel flowing through has a more axial flow direction for the mixture of air and fluid fuel flowing through the slot. This discontinuity is preferably positioned to flow the mixture of air and fluid fuel through a mixing zone which is preferably stepwise treated outside of the combustion zone. The crown also axially aligns the gas nozzle containing the opening therein.

In one preferred embodiment of the invention, the tip described in the paragraph above is used in combination with a burner assembly composed of a composite venturi tube structure as described above.

The present invention also provides a method of increasing the capacity of a venturi tube to induce a flow of a second fluid into the first fluid as the flow of the first fluid flows through the device. The method comprises the steps of separating the first fluid into at least two, preferably at least three, optionally at least six, separate streams, and each flow to separate the mixture of the first and second fluids, respectively. Passing each separate flow portion of the first fluid through each venturi tube to individually direct the flow of the second fluid into the buoy, passing the total amount of the first fluid passing through the single venturi tube more than is possible. Mixing each separate separation mixture to produce a mixture of the first and second fluids containing a high concentration of the second fluid. According to the invention, preferably the first fluid is a gas fuel and the second fuel is air.

In addition, the present invention provides a method of reducing the length of a venturi tube device adapted to direct the flow of a second fluid into the first fluid as the flow of the first fluid passes through the device. In this form of the invention, the method comprises the steps of separating the first fluid into at least two, preferably at least three, or at least six separate flow sections; Passing each separate flow section of the first fluid through each venturi tube individually directing the flow of the second fluid within each flow section of the first fluid to separate the mixture of the first and second fluids separately; and ; Mixing each separate mixture to pass a total amount of the first fluid through a single venturi tube of the same length to produce a mixture of first and second fluids containing a second fluid that is more concentrated than is possible; Include.

Moreover, the present invention provides a method of operating a venturi tube device, in which each venturi tube consists of an inlet, a neck and an outlet, so as to create a separate mixture of the induced substance and the induced fluid as it is passed. Providing at least two venturi tubes operable to direct the flow of the induced material and to discharge the mixture from the outlet; Passing the first induction fluid through the first venturi tube to direct the induced flow of the first material and to produce a first mixture of the first induction fluid and the induced first material, and from the outlet of the first venturi pipe Discharging the mixture; Passing the second induction fluid through the second venturi pipe to induce the flow of the induced second material and to produce a second mixture of the second induction fluid and the induced second material, and from the outlet of the second venturi pipe Discharging the mixture; And collecting and mixing the first and second mixtures to create a single mixture flow of fluid and material.

In addition, the present invention provides a method of operating a burner installed in a venturi tube device that provides a burner nozzle with a combustible mixture, which is formed when each venturi tube consists of an inlet, a neck and an outlet, and an induction fluid is passed through them. Providing at least two venturi tubes operable to direct the flow of the induced fluid to produce a separate mixture of the fluid and the guide fluid and to discharge the mixture from the outlet; Passing the first induction fluid through the first venturi tube to induce the flow of the induced first fluid and to produce a first mixture of the first induction fluid and the induced first fluid, and from the outlet of the first venturi pipe Discharging the mixture; Induces the flow of the induced second fluid and produces a second mixture consisting of the second induction fluid and the induced second fluid, passes through the second venturi pipe, passes the second induction fluid, Discharging the mixture; Collecting and mixing the first and second mixture to create a combustible single mixture flow of fluids. Ideally, the first and second induction fluids are respective gaseous fuels and the induced first and second fluids are recycled flue gases or diluents such as steam, nitrogen, carbon dioxide or other inert gas.

1 is a front view of a burner assembly having a multiple composite venturi tube cluster implementing the concept and principle of the present invention;

FIG. 2 is a view similar to FIG. 1 except for a partial cross section of the assembly exposing the inner member;

3 is a plan view of the burner assembly shown in FIG.

4 is a cross-sectional view taken along line 4-4 of FIG. 2;

5 is a cross-sectional view taken along line 5-5 of FIG. 2;

6 is a partial cross-sectional view illustrating a part of another multi-composite Venturi tube cluster implementing the concept and principle of the present invention;

FIG. 7 is an enlarged detail view of a portion 7 of the multi-component Venturi tube cluster of FIG. 6;

8 is a perspective view of an embodiment of a burner tip for realizing the concepts and principles of the present invention and used in conjunction with the multiple composite venturi tube cluster of the present invention in a burner assembly;

9 is a plan view of the burner tip shown in FIG.

10 is a perspective view of another embodiment of a burner tip for realizing the concepts and principles of the present invention and used in conjunction with the multi-compound Venturi tube cluster of the present invention in a burner assembly;

11 is a schematic diagram of another embodiment of a burner assembly that realizes the concepts and principles of the present invention;

Figure 11a is a partial view illustrating another structure of the burner assembly shown in Figure 11,

12 is a schematic diagram of another embodiment of a burner assembly in which the concept and principle of the present invention are realized;

13 is a partial cross-sectional view illustrating a downstream portion of another burner assembly in which the concept and principle of the present invention are realized;

14 is an enlarged cross-sectional view illustrating a part of the burner assembly shown in FIG. 13 in detail;

15 is a plan view of the burner assembly shown in FIG. 13;

FIG. 16 is a schematic diagram of a burner assembly similar to the burner assembly of FIGS. 11 and 11A except that the central venturi bundle is surrounded by the surrounding venturi bundle.

The present invention provides several new aspects that can be combined or used independently. In particular these aspects are used in connection with a burner or burner assembly adapted to burn fluid fuel. Fluid fuels are fuel oils or similar materials, preferably natural gas, propane, butane or hydrogen, or similar gaseous fuels.

One burner assembly incorporating the concepts and principles of the present invention is illustrated in FIGS. The burner assembly 20 has an outer, generally cylindrical lid 22, and a series of second fuel nozzles 24 connected to the fuel manifold 26 and mounted circumferentially. As shown in FIGS. 2 and 4 and 5, the assembly 20 further comprises a venturi tube cluster 30 composed of six individually separated venturi tubes 32 as shown. And (28). Each venturi tube 32 has an inlet 34 at the lower or upstream end (as shown in FIG. 2), a neck 36, and an outlet 38 at the upper or downstream end. As shown in FIGS. 2, 4, 6, and 7, the injection end 35 of the venturi tube extending from the inlet 34 to the neck 36 is open to the outside and is essentially conical or longitudinal. It is shaped.

Individually, the venturi tube 32 is a type of conventional venturi tube type structure that is well known to skilled workers in burner technology, and the venturi tube simply passes through the induction fluid to induce the flow of the induced material. Is converted and arranged to be. With this phenomenon, each mixture of induced material and induced fluid is made in the venturi tube and discharged through the outlet 38 at the downstream end of the venturi tube.

The structure 28 also includes a collector 40 having an injection stage 42 connected and arranged as shown in FIG. 2 to communicate fluid to the outlet 38 of the venturi tube 32. As will be apparent to those skilled in the art, the upper end of the venturi tube 32 adjacent the outlet 38 defines a flexible transition zone 41 in which the outlet 38 couples with the injection end 42 of the collector 40. To have a suitable shape as shown schematically in FIG. With the advantage of this arrangement, each mixture leaving the outlet 38 at the downstream end of the venturi tube is gathered in the collector 40 and mixed to form a single mixing flow. In order to promote mixing, the collector 40 has a radially expanded extension 43 as shown.

The venturi tube cluster has six individual venturi tubes shown in FIGS. 2, 4 and 5, but as will be apparent to those skilled in the art, the clusters are made as few as two venturi tubes arranged in parallel. It may be. In contrast, the cluster even has at least 6, such as at least 12 venturi tubes, depending on the needs of the given application.

As will be apparent to those skilled in the art, the induction fluid for venturi tubes is different. In addition, the derived materials do not all need to be identical. In the case of a burner, for example, the induction fluid is a gaseous fossil fuel or a fuel such as hydrogen, while the induced material is for example air or a fluid such as a combustion-inert diluent such as recycled flue gas, steam, carbon dioxide or nitrogen. Alternatively, the induced fluid is air, while the induced material uses fluid fuel or diluent. In some cases, each mixture produced in each venturi tube 32 is well mixed in the collector 40 so that when the venturi tube cluster 30 is used in the burner, it contains a single oxidant, a fluid fuel and a suitable diluent. Create a mixed flow.

In order to use the concepts and principles of the present invention in connection with a burner, preferably the induction fluid is a fluid, more preferably a gaseous fuel, and the induced material is preferably a gas containing oxygen, more preferably air. . For this reason, the burner assembly 20 has a series of fuel gas injection tubes 44 connected to a common fuel source, not shown in the figures. The burner assembly 20 also includes a series of control handles 46, one for each venturi tube 32. The handle 46 can be operated to move each control member 48 in a conventional manner to direct or exit the inlet 34 of the corresponding venturi tube 32, passing the inlet tube 44 through the inlet 34. Control the amount of air drawn from the surrounding air box to the corresponding venturi tube 32 due to the pressurized fuel gas flowing into the). The air box is indicated generally by the reference numeral 50 in FIG.

According to the structure described above, when the fuel gas is discharged into each venturi tube through the corresponding tube 44, the air from the air box 50 is the gap 52 between each inlet 34 and the corresponding member 48 It is drawn through the inlet 34 through. The amount of air drawn into the inlet 34 is controlled by varying the width of the gap 52 by raising or lowering the member 48 using the corresponding handle 46. The air drawn into the inlet 34 due to the fuel gas flowing through the tube 44 to the inlet 34 is combined with the fuel gas discharged from the tube 44, and thus the fuel gas and air flowing through the venturi tube 32. And a mixture is discharged from the venturi tube 32 through the outlet 38.

In particular, a detailed description of the air control is shown very well in FIGS. 6 and 7, with the components of three venturi tube burner assemblies. In this regard, the venturi tube 32 of FIGS. 6 and 7, the tube 44, the handle 46, and the control unit 48 are essentially corresponding components of the assembly 20 of FIGS. 1 and 2. Same as the Therefore, the clearance 52 opens when the handle 46 is turned in the forward direction, and the clearance 52 is narrowed when the handle 46 is turned in the opposite direction. 6 and 7 also have a central fuel supply system to achieve the purpose described below.

Each mixture, independent of the venturi tube 32, is collected and mixed into the collector 40 and burner tip 54 which distributes into the combustion zone 56 surrounding the top end 58 of the burner assembly 20 as a whole. It provides a single mixed flow of oriented fuel gas and air. As shown in FIG. 2, the collector 40 is preferably elongated in that direction along the longitudinal center axis 60 of the burner assembly 20, which has an outlet or downstream end 62. The burner tip 54 is positioned above it.

Preferably, the venturi tubes 32 are arranged to flow in parallel in the cluster 30, and each mixture produced in the venturi tubes is combined together to provide a single combustible premix of air and fuel together. Supplied to the unit 40. This premix is directed to a common premix tip 54 mounted at the downstream end 62 of the collector. The premix tip 54 is essentially in such a way that if only a single venturi tube is used, the pressure inside the tip is equal to the pressure that would normally be provided. This ensures that the pressure drop associated with the velocity of the gas is related to a single venturi tube. The use of multiple venturi tubes allows the use of multiple gas spuds (injectors) which alternately disperse air in simple gas injection at the same rate. The additional surface area of the three single jets (or more, as specially required in a given application) makes it possible to detect an increase in the air dispersed by the jets. In addition, since the entrainment velocity of the induced fluid changes directly with the surface area of the induction flow, it is entrained by the opening of the venturi tube by the momentum of the injection. Additionally entrained air is a function of the momentum of the gas as well as the number of gas injections used once the air leaves the spud (injector).

In one embodiment of the present invention, the venturi tube cluster 30 includes six venturi tubes 32, as described above with respect to FIGS. In other words, in a preferred form of the present invention, the cluster 30 comprises at least two, at least three, or even at least six venturi tubes. For example, a burner assembly using three venturi tubes is illustrated in FIGS. 6 and 7. In this regard, the only limitation is that the venturi tubes of each cluster discharge from each venturi tube to a general collector 40 where the independent mixture is mixed together to form a single mixing flow. In the above embodiment, the induced fluid is described as fuel gas and the induced fluid is described as air.

In a preferred embodiment of the present invention, each capacity of the independent venturi tube is the same. However, according to the broad contemplative aspects of the present invention, the independent venturi tubes of a given cluster need not be identical. That is, the capacity of one or more venturi tubes of a given cluster may be different from the capacity of one or more other venturi tubes of the same cluster. Moreover, the induction fluid of one or more venturi tubes of a given cluster is different from the induction fluid of one or more other Venturi tubes of the same cluster. In addition, the induced fluid of one or more venturi tubes of a given cluster is different from the induced fluid of one or more other Venturi tubes of the same cluster. By way of example only in this respect, the induced fluid of one venturi tube of a given cluster is air, while the induced fluid of another venturi tube of the same cluster is a flue gas or a diluent such as nitrogen or steam. In addition, as in other examples for burners, the induced fluid is air and the induced fluid is fuel gas. As will be readily appreciated by those of ordinary skill in the burner art, many possible combinations of the capacity of venturi tubes and guide fluids and induced fluids are usefully employed in a single venturi tube cluster according to the concepts and principles of the present invention.

The number of venturi tubes used at any given time for a given application is determined by the burner geometry as well as the heat release of the burner. To achieve very low nitrogen oxide emissions, one or more venturi tubes are used to draw flue gas from the furnace, while the remaining venturi tubes are used for gas and air. The flue flue of the furnace is mixed with a mixture of fuel and air from other venturi tubes in the collector 40, thereby adding mass to the overall combustion flow. As the reaction rate slows, the additional load of flame caused by the additional mass lowers the temperature of the flame, thus reducing the release of nitrogen oxides. Depending on the use of a homogeneous premixed mixture of gas and air, such as the main fuel element of other burner structures, this concept can not only reduce the release of nitrogen oxides in other types of burners but also provide a wide range of heat release. .

The use of multiple venturi tubes that supply fuel and air premixes facilitates the provision of very fuel lean premixes. These very fuel lean premixes preferably contain only about 55% of the total fuel required, and often even below, while containing all the oxygen needed to burn the total fuel. Then, the residual fuel is fed along with the second fuel past the nozzle treated in stages. The concept of a very thin premix, which maintains the ratio of gas to air above the low combustion limit, provides the maximum load on the heat generated by the main flame. Multiventuri tube arrangements are useful for very thin premixes, while maximizing the ability to stage untreated rich gas streams, such as staged gases. Dispersion premixed gas streams combined with flue gas entrained in staged gas injection offer new opportunities for the reduction of nitrogen oxides. Nitrogen oxide release performance was observed as low as 3 ppm per unit volume in the burner structure.

As illustrated in FIGS. 2, 4, 5 and 6 and described above, the surface area of the multi-spray contained separately in the longitudinally injecting bells 35 concentrating independently is more effective in entrained air. This is due to the surface area of the additional spray and the reduction in diameter created by separating one large spray into many smaller sprays. The size of the injection is reduced as a function of the diameter of the branch and port of the injection in the surrounding fluid. The divergence angle, which is also a function of the structure of the gas port, has a determinant on the surface area of the injection. When supplied at the same fuel pressure, each injection made using separate gas ports and multiple venturi tubes will entrain and diffuse air at the same rate. This rate of diffusion / entrainment will increase the burner's ability to deliver fuel-lean or very thin premixes. Although not required, the composition of the premix from the multiventuri tube cluster can be adjusted to below the flammability limit of the mixture. By maintaining the composition of the premix within the flammable limits of the fired fuel, the mass of air is maximized as much as possible to maximize the thermal load on the flame. The additional thermal load reduces the temperature of the flame, reducing the formation of thermal nitrogen oxides.

An embodiment of another burner assembly that realizes the principles and concepts of the present invention is schematically illustrated in FIG. 11, indicated by reference numeral 120. In Fig. 11, components which are essentially the same as the components shown in connection with Figs. 1 to 5 are denoted by like reference numerals. In FIG. 11, the venturi tube cluster 30 is shown as having only two venturi tubes 32, but as described above, the cluster 30 of FIG. 11 may have three or four or more depending on the available space. It can have more than one venturi tube. As shown in FIG. 11, the venturi tube 32 has an elongated, essentially straight tube 64 extending between the neck 36 and the outlet 38. And, as shown, the tubes 64 are arranged essentially parallel to each other. In particular, the tube 64 is arranged to flow in parallel with the flow of the fluid. In this regard, the structure shown in FIG. 11 is not essential to the performance of the cluster 30. Moreover, as is known to those skilled in the art, downstream 64 of the venturi tube need not be straight and need not be positioned parallel to each other.

Preferably, the burner tip 154 of the burner assembly of FIG. 11, illustrated in more detail in FIG. 10, is elongated along the axis 60 direction, which burner tip is oriented from the collector 40 to the axis 60 direction. And are adapted and arranged to direct a single mixed flow of fuel and air contained in zone 56 outwardly. For this reason, the tip 154 has a plurality of openings 66 in the downstream end, which openings 66 direct the direction of the mixing flow of fuel and air along the axis 60 as shown in FIG. Is positioned to set.

As shown in FIG. 11, the venturi tube 32 provides the supply of fuel gas via an injection pipe or spud 68, and the airflow is as described above using the movable control member 48. Controlled in the same manner (handle 46 is not shown in FIG. 11). Therefore, in the embodiment of Fig. 11, the fuel gas is an induced fluid and air is an induced fluid. In addition, the assembly 120 of FIG. 11 extends along the central axis 60 of the assembly 120 and passes through a hole 69 in the downstream end 67 of the tip 154 as shown. A fuel tube 70 is provided. A small venturi tube 72 is provided at the upstream end 74 of the tube 70, and the supply of main fuel to the tube 70 is supplied via the injection fuel spud or pipe 76. Therefore, the main mixture of air and fuel flows along the tube 70 toward the main nozzle 78 located at the top of the downstream end 80 of the tube 70 located in the combustion zone 56. Here, according to the present invention, the material supplied to the nozzle 78 is preferably a premix of air and fuel, while natural fuel can be supplied to the nozzle 78 for stabilization.

As shown in FIG. 11, the openings 66 are arranged so as to surround the tube 70. Therefore, the combustible mixture of fuel and air exits the opening 66 at the tip 154, which is cylindrical in shape extending toward the nozzle 78 as it surrounds the tube 70. Upon ignition of the combustible mixture, an overall cylindrical flame is created which extends along the axis 60.

The flame holder 82 to be mentioned below is mounted to the tube 70 directly under the nozzle 78. Details of any preferred embodiment of flame holder 82 and nozzle 78 are shown in FIGS. 13 and 14. However, the burner tip 254 illustrated in FIG. 13 is different from the burner tip 154 of FIG. 11, while the burner tip 154 has a plurality of openings 66 in the end wall 156. Burner tip 254 has a cylindrical shape that is essentially wide open at downstream end 256.

Referring to FIG. 13, the flame holder 82 is preferably conical with a peak 84 at a point away from the nozzle 78. As shown in FIG. Preferably, peak 84 is positioned about 8 inches above the top end of tip 254. In a particularly preferred embodiment of the present invention, when the tube 70 is formed of a 1 inch diameter pipe, the flame holder 82 has an outer diameter of about 4 inches, and the flame holder has a tack weld or set screw. Or the like is formed in the shape of a plate attached to the tube (70). The inner angle α between the shaft 60 and the skirt 83 of the cone of the flame holder 82 is preferably 45 °.

In the most preferred form, the holder 82 has a plurality of 1/4 in holes 86 dispersed in a pattern surrounding the tube 70. Ideally, the holes 86 are of sufficient size and number so that the opening area occupies about 30% of the surface area of the holder 82. However, in accordance with the principles and concepts of the present invention, the opening area ranges from less than about 10% to about 75% or more of the surface area of the holder 82. In contrast, according to the present invention, the holder has a different diameter depending on the diameter of the main burner opening in the furnace. Therefore, the diameter of the holder 82 varies from one quarter of the diameter of the main burner opening in the furnace to the same size as the main burner opening in the furnace. In addition, the angle α ranges from about 30 ° or less to about 80 ° or more. In addition, in connection with the foregoing, the shape of the holder 82 is not limited, and the holder can deflect the combustible mixture leaving the tips 154,254, leading to the combustible mixture into a stagnant slow zone where ignition is stabilized and maintained. All arbitrary shapes are used so long as the low pressure portion 300 can be made downstream of the flame holder 82.

The nozzle 78 is preferably in the form illustrated in FIG. 14, with a base 88 consisting of a cylindrical upper cup portion 90 having a perforated and machined hexagonal pole and an open top end 92. Is done. The base portion 88 has a hole 94 and the cup portion 90 has a hole 96, which holes 94 and 96 are necessary to achieve a result suitable for the nozzle 78 providing the desired coin flame. It is located in size. The cup portion 90 protects the flame ejected from the opening tip 87 of the base portion 88 by the ambient gas flow. Without this flow, the cup 90 is not necessary.

The structure schematically illustrated in FIGS. 11 and 13 and 14 has very good nitrogen oxide performance. As mentioned above, the concept of a multiple venturi tube can itself provide a very fuel lean premix that reduces the release of nitrogen oxides. If the concept of a multiple venturi tube is connected to the structures of Figs. 11, 13 and 14, a low release of nitrogen oxides can be achieved with the stabilization of the low speed zone of the very thin premix.

Referring again to FIG. 11, a small portion, often less than 10% of the total fuel, and preferably 2% or less, is inserted through the spud 76 and used to release air from the air box 50. Fuel and air are premixed in the tube 70 shown through the center of the burner. As described above, in some cases it is desirable to supply natural fuel via the tube 70. The tube 70 terminates in a shielded nozzle 78 which is passed through the master mixing gas tip 154 and positioned some distance above the master mixing tip 154. This distance varies from about 3 inches or less to 15 inches or more depending on the speed and pressure of the premix leaving the tip 154 and the size of the burner. Therefore, a small coin flame is installed in the nozzle 78 raised at a point above the upper tip 156 of the master mixture tip 154. A cone-shaped flame holder 82 made from a perforated plate is positioned just below the raised nozzle 78 to a position where the master mixture is attracted from the tip 154 to a stable main flame made adjacent to the nozzle 78. to provide. The cone 82 and main nozzle 78 therefore have a mechanism for stably maintaining the flame in the very thin fuel premix supplied from the tip 154. Once the flame has stabilized, the main flame produced at the discharge end 92 of the nozzle 78 is further digested to further reduce the release of nitrogen oxides.

Positioning the main flame in the manner described above at an actual distance from the outlet of the main burner tip 154 provides an opportunity for the main mixture of air and fuel to expand and decelerate after exiting the main burner tip 154. Slowing the premix at a rate slower than the flame speed allows the flame of the premixed fuel to be very lean. An important problem that occurs when very fuel lean combustible mixtures are used is that the flame speed directly changes the fuel content. Therefore, the flame speed becomes very slow in very fuel-lean mixtures. In addition, the temperature of the mixture affects the flame velocity to a higher temperature resulting in a faster flame velocity and vice versa. In other words, when the combustible mixture is very lean, if the excess air content is high, the rate of flow exiting the main burner tip will exceed the flame speed, which will cause the burner tip to burst.

The ignition is delayed, creating a situation where the flame speed exceeds the flow rate until the main mixture of fuel and air exits the tip and expands in the furnace space until the speed is reduced and heated with radiant heat in a high temperature environment. Thereby, the flame is easily maintained in a stable state in the stabilization zone provided with the raised nozzle 78 and the holder 82. With the low-speed zone stabilization method, which is actually distanced from the main mixing tip outlet, the ignition and combustion of the main gas is approximately 5 ppm of natural gas, which is previously unattainable, e.g. 25% hydrogen, 25% propane, 50% methane. Less than 3% of the spent fuel gases are produced with low emissions of nitrogen oxides. In addition to the foregoing, preliminary mixtures already thin in fuel are further diluted before firing by entraining the flue product after exiting the main tip and during expansion and deceleration. It can also further reduce the emission of nitrogen oxides.

According to the structure illustrated in FIG. 11, a very lean but stable mixture of operating the central venturi tube 72 within the flame limits, which is below the flame limits and must be followed by the temperature of the furnace to complete the oxidation of the fuel. It is possible to drive the surrounding multiple venturi tube and the general collector 140.

According to another aspect of the present invention, the mixture of fuel and air in the tube 70 is supplied in a cluster structure having a plurality of venturi tubes 70. This structure is schematically illustrated in FIG. 11A. In this case, the overall assembly is preferably provided with two separate venturi tube clusters, an external one for supplying a premix of air and fuel to the burner tip 154 and an example of air and fuel to the tube 70. It is equipped with the inside which supplies a mixture. The structure of another scheme in which the inner multiventuri tube bundle is completely surrounded by the outer venturi tube bundle is schematically illustrated in FIG. As shown in FIG. 16, the outer venturi tube bundle includes a venturi tube 32 and a general collector 140, while the inner venturi tube includes a venturi tube 72 and a general collector 340. In this case, in a structure with an inner ventilator bundle located within the outer ventilator bundle, the inner cluster operates within a stable flame limit, while the outer cluster is characterized by the use of highly fuel-lean air and lean fuel to maximize the conditions necessary to reduce NOx emissions. It is operated to provide a premix of fuel. This type of arrangement is used for the construction of very large burners with 6 or more venturi tubes in the inner bundle and 12 or more venturi tubes in the outer bundle.

Referring to FIG. 12, the principles and concepts of the present invention are used in radial burners where the premix is directed radially at the tip 354. In this regard, reference is made to US patent application Ser. No. 09 / 803,808, filed and assigned March 12, 2001, which is incorporated herein by reference. Therefore, the burner assembly 320 shown schematically in FIG. 12 has an elongated burner tip 354 extending in the axial direction through the burner assembly and is generally radial to the axis 60 from the collector 40. It is adapted and arranged to direct the direction of the single mixing flow received in the combustion zone 56 in the direction of. Therefore, burner tip 354 is adapted and arranged to produce a round and flat flame surrounding tip 354. Referring to FIG. 12, the assembly 320 includes a center tube 170 to supply a second fuel to the combustion zone via the nozzle 178.

In particular, in a preferred form of the present invention, the burner tip 354 is in the shape illustrated in FIGS. 8 and 9, in which the tip 354 is generally annular base 98 and central axis 100. You can see). In addition, tip 354 has a plurality of elongated, parallel, circumferentially spaced longitudinally curved ribs 102. Rib 102 has a separate first end 104 mounted to base 98 and a separate second end 106 spaced from base 98. As shown, the second end 106 is located closer to the axis 60 than the first end 104. The rib 102 and base 98 define an area 108 inside the tip 354 adapted to receive a flow of fuel and air homogenous from the collector 40. Rib 102 defines a plurality of curved slots 110 therebetween. As shown in FIGS. 8 and 9, the slot 110 has a tip 354 in a direction in which the mixture within the region 108 has a vector extending along the axis 60 and in a radial direction from the region 108. It flows outward into the combustion zone 56 from the outside.

In the preferred form illustrated in FIGS. 8 and 9, the tip 354 also has a crown 112 connected to a separate second end 106 of the tip 354. Preferably, crown 112 has a plurality of axially extending discontinuities 114 aligned with constant slots 110, leaving mixture 108 beyond these discontinuities 114. Directs the flow in the axial direction rather than the mixture leaving slot 110 past slot 110. Ideally, the discontinuity 114 is a region 116 in the direction indicated by the arrow 115 to dilute the flue gas before returning to the continuous zone where the mixture of air and fuel flowing through the discontinuity 114 is combusted. A staged mixing zone 116 (shown in FIG. 12) outside the combustion zone 56, which is the point of circumference, is created and thereby positioned to cause the axially oriented mixture to flow. In comparison, the flow direction of the premix flowing from the slot 110 is schematically illustrated by arrow 117. In a particularly preferred form of the invention, the crown 112 of the tip 354 has an axially aligned central gas nozzle that receives the opening 118.

In one aspect, the present invention has a burner with radial walls with a composite Venturi tube cluster and can achieve high heat release with 100% premix. This was not possible in the prior art of the present invention. Conventionally, high heat emission has been achieved with the second air and 1.7 MMBTU / h. On the other hand, the second air typically emits more nitrogen oxides than when all the air is supplied to the venturi tube as a premix of air and fuel. This problem has been overcome with the new structure described to have a composite Venturi tube cluster consisting of multiple Venturi tubes arranged in a single cluster to flow fluid in parallel.

The present invention provides for the reduction of the release of nitrogen oxides into staged fuels, the reduction of noise in some constructions, the staged gas injection entraining flue gases outside the burner, the rapid reduction of nitrogen oxides, and the action of secondary air. Simplification of operation, short flame profile, high turn down ratio with added premix tip speed, high stability, minimization of carbon dioxide emission, cooling premix tip (adding mass flow and higher heat transfer) And an additional tip speed to provide minimization of flame backflow.

The present invention relates, among other things, to the structure of multiple venturi tubes, providing excess air to very thin fuel mixtures that employ premixes. In particular, the invention is used in connection with a burner with radial walls or a burner providing flame in the axial direction. The present invention is also used in conjunction with a large process for heating burners with flammable premixes consisting of 100% or some premixes as a mechanism for reducing the release of nitrogen oxides. The structure of the multiventuri tube of the present invention has a general application and can be used generally whenever the venturi tube is used. In particular, the multiventuri tube structure of the present invention conventionally operates to entrain air more than increase mass transfer and diffusion. Moreover, the multi-venturi tube structure of the present invention is beneficial for applications to conventional tanks and for the discharge of vessels, for the adjustment of air, for the transport of solids, and for the adjustment of solids, and short venturi tubes are needed to transport large masses of material. Useful anywhere

In the past, burners with radial walls cannot achieve heat release in excess of 1.5 MMBtu / h without the use of other air sources. With the use of parallel multiple venturi tubes, heat releases in excess of 10 MMBtu / h can be achieved by ensuring internal reactions between the transferred mechanical structure and minimized venturi tubes.

In one structural form according to the invention, the invention can be used for the modularization of burners in which venturi tube eductors are added to increase the capacity or reduce the release of nitrogen oxides. In this concept, the burner can be installed in multiple venturi tubes and subsequently retrofitted further venturies to increase capacity, add steam or flue gases or inert gases, and reduce emissions of nitrogen oxides. In other structural configurations, the present invention does not limit the use of flue gases such as diluents that reduce the release of nitrogen oxides, but any other diluent may be used that adds mass to extinguish the flame. These diluents can be used for any inert gas such as nitrogen, or carbon dioxide that has lowered the BTU with fuel such as steam or purified PSA gas, or even other lean fuel vapors or gas vapors containing some flammable gas.

In other structural shapes, the present invention may use many different structures in the process of heating burners mounted to the bottom or roof of the furnace instead of sidewalls. As they soar, they create a round, flat, or other shaped flame. This works in furnaces that are not needed for flame heated walls.

In another structural configuration, instead of the fuel used with the moving fluid in one or more outlets, steam or other compressed dilute gases as described above are used as the moving fluid.

A typical radial wall burner uses the power of a single gas spud to entrain air from the atmosphere. The new concept of using multiple venturi tubes or parallel vents adds a new aspect to the combustion industry. In the present invention when used in burner technology,

(1) a short flame due to homogeneity of gas and air;

(2) as high a turndown ratio as possible (10: 1 as opposed to 3: 1 for conventional devices);

(3) low noise around the burner;

(4) tiles unaffected by hot spots made by combustion spray through the tiles;

(5) 100% premix without the need for a second register;

(6) the operation of a very stable burner;

(7) burners operable with additional stoichiometry without flame backflow;

(8) the ability to lower nitrogen oxides in a rapid and thermal manner by injection and mixing of flue gases;

(9) step-by-step processing of fuels easily achieved with a single internal or multiple radiation tip;

(10) countercurrent to volatile fuels to minimize fast tip speeds;

(11) Heat releases that can be achieved greater than ever; are important.

According to the concepts and principles of the present invention, the burner with the new composite venturi cluster is designed to burn up, down or horizontally. Furthermore, the multiple venturi tube burners of the present invention are used by burning flammable liquids such as fuel oil. Therefore, burners that minimize discomfort and minimize physical changes are used in combination with the combustion arrangement. In addition, the burner of the present invention can be easily retrofitted into various shapes. For example, the burner is in the form of a rectangle or other preferred shape that replaces the round flame structure described above.

It is also contemplated that the venturi tube cluster can be used in combination with a central nozzle tube providing pure fuel to a central nozzle supplying a mixture of fuel and air to a central main flame nozzle or a second fuel to a combustion zone. .

In addition, the concepts and principles of the present invention are used to provide a large burner array having an internal multiple venturi tube cluster located within an external multiple venturi tube cluster.

The present invention provides a number of new aspects that are used alone or in combination with a burner or burner assembly suitable for burning fluid fuel. Fluid fuels use fuel oils or the like, preferably gaseous fuels such as natural gas, propane, butane or hydrogen or similar gases.

As described above, according to the present invention, the burner assembly includes a venturi cluster having a plurality of venturi tubes, and the fluid flows in parallel to reduce various problems of the existing burners, in particular, the emission of nitrogen oxides, and the fuel mixture. The rate of deceleration is significantly slowed down to produce a stabilized flame.

Claims (133)

At least two venturi tubes, each venturi tube having an inlet, a neck, and an outlet and adapted and arranged to induce a flow of the induced material through the induced fluid through the inlet fluid; A venturi tube cluster for discharging the individual mixture from the outlet port; An injection stage is connected and arranged in fluid communication with the outlet of the venturi tube, whereby a separate mixture of inducer and induced material discharged from the outlet is collected and mixed to provide a single mixing flow of the fluid and material. Composite venturi tube structure having a. The composite venturi tube structure according to claim 1, wherein the cluster has at least three venturi tubes. 3. The composite venturi tube structure according to claim 2, wherein the cluster has at least three venturi tubes. 2. The composite venturi tube structure according to claim 1, wherein each venturi tube is an elongated tube, and an injection end of the venturi tube is a ball shape. 5. The composite venturi tube structure according to claim 4, wherein the tubes are arranged essentially parallel to one another. 3. The composite venturi tube structure according to claim 2, wherein each venturi tube is an elongated tube, and the injection end of the venturi tube is a ball shape. 7. The composite venturi tube structure according to claim 6, wherein the tubes are arranged essentially parallel to each other. 4. The composite venturi tube structure according to claim 3, wherein each of the venturi tubes is an elongated tube, and the injection end of the venturi tube has a ball shape. 9. The composite venturi tube structure according to claim 8, wherein the tubes are arranged essentially parallel to one another. The composite venturi tube structure according to claim 1, wherein each venturi tube has essentially the same physical capacity. The composite venturi tube structure according to claim 1, wherein at least one venturi tube has a different physical capacity than the other venturi tube. 3. The composite venturi tube structure according to claim 2, wherein each venturi tube has essentially the same physical capacity. 3. The composite venturi tube structure according to claim 2, wherein at least one venturi tube has a different physical capacity than the other venturi tube. 4. The composite venturi tube structure according to claim 3, wherein each venturi tube has essentially the same physical capacity. 4. The composite venturi tube structure according to claim 3, wherein at least one venturi tube has a different physical capacity than the other venturi tube. At least two venturi tubes, each venturi tube having an inlet, a neck, and an outlet through which are adapted and arranged to direct the flow of the induced material through the induced fluid, thereby providing a separate A venturi tube cluster for discharging the mixture from the outlet port; An inlet end is connected and arranged in fluid communication with the outlet of the venturi tube such that a collector and the individual mixture of induced and discharged substances discharged from the outlet are gathered and mixed to provide a single mixing flow of the fluid and ; A burner tip attached to the discharge end of the collector to communicate with the fluid and arranged to receive the single mixed flow of fluid from the collector and to direct the single mixed flow of fluid in a combustion zone; Burner assembly. 17. The device of claim 16, wherein the tip is elongated in shape and adapted and arranged to direct the single mixed flow into the zone and out of the tip in a generally radial direction with respect to the longitudinal axis of the tip. Burner assembly. 18. The burner assembly of claim 17, wherein the tip is adapted and arranged to create a round and flat flame surrounding the tip. 17. The burner of claim 16, wherein the tip is elongated in shape and adapted and arranged to direct the single mixed flow into the zone and out of the tip as a whole relative to the longitudinal axis of the tip. Assembly. 20. The burner assembly of claim 19, wherein the tip is adapted and arranged to produce a cylindrical flame extending along the axis. 17. The burner assembly of claim 16, wherein said cluster comprises at least three said venturi tubes. 22. The burner assembly of claim 21, wherein said cluster comprises at least six said venturi tubes. 17. The burner assembly of claim 16, wherein each venturi tube comprises an elongated tube, the injection end of the venturi tube being longitudinal. 24. The burner assembly of claim 23, wherein the tubes are arranged essentially parallel to each other. 22. The burner assembly of claim 21, wherein each venturi tube consists of an elongated tube, the injection end of the venturi tube being ball shaped. 26. The burner assembly of claim 25, wherein the tubes are arranged essentially parallel to one another. 23. The burner assembly of claim 22, wherein each venturi tube consists of an elongated tube, the injection end of the venturi tube being ball shaped. 28. The burner assembly of claim 27, wherein the tubes are arranged essentially parallel to one another. 17. The burner assembly of claim 16, wherein the venturi tubes have essentially the same physical capacity. 17. The burner assembly of claim 16, wherein the at least one venturi tube has a different physical capacity than the other venturi tube. 22. The burner assembly of claim 21, wherein the venturi tubes have essentially the same physical capacity. 22. The burner assembly of claim 21, wherein at least one venturi tube has a different physical capacity than the other venturi tube. 23. The burner assembly of claim 22, wherein the venturi tube has essentially the same physical capacity. 23. The burner assembly of claim 22, wherein at least one venturi tube has a different physical capacity than the other venturi tube. 31. The burner assembly of claim 30, wherein the at least one venturi tube is adapted and arranged to operate using gaseous fuel as an induction fluid. 36. The burner assembly of claim 35, wherein the at least one venturi tube is adapted and arranged to operate using air as an induced fluid such that the single mixture flow consists of fluid fuel and air. 36. The burner assembly of claim 35, wherein said at least one venturi tube is adapted and arranged to operate using recycled flue gas as an induced fluid such that said single mixed flow consists of fluid fuel and recycled flue gas. 37. The system of claim 36, wherein the other venturi tube is adapted and arranged to operate using gaseous fuel as induction fluid and recycled flue gas as induced fluid such that the single mixture flow is fluid fuel, air and recycled. Burner assembly consisting of flue gas. 36. The burner assembly of claim 35, wherein said at least one venturi tube is adapted and arranged to operate using an inert diluent for combustion as an induced fluid such that said single mixture flow consists of a fluid fuel and said inert diluent for combustion. 40. The burner assembly of claim 39, wherein said diluent is vapor. 40. The burner assembly of claim 39, wherein said diluent is nitrogen. 34. The burner assembly of claim 33, wherein the venturi tube is adapted and arranged to operate using gaseous fuel as induction fluid and air as induced fluid, such that the single mixture flow consists of gaseous fuel and air. 17. The burner assembly of claim 16, wherein said induction fluid is a gas fuel. 17. The burner assembly of claim 16, wherein said induction fluid is fuel oil. 17. The burner assembly of claim 16, wherein said induced fluid consists of air. 44. The burner assembly of claim 43, wherein said induced fluid consists of air. 17. The burner assembly of claim 16, wherein the collector is elongated and has a central axis extending between the tips of the collector. 48. The burner assembly of claim 47 having a central fuel tube extending along the axis through the collector. 49. The burner assembly of claim 48, wherein the opening end of the collector comprises at least two opening members and the outlet of the venturi tube is connected to each member, respectively. 22. The burner assembly of claim 21, wherein the collector is elongated and has a central axis extending between the tips of the collector. 51. The burner assembly of claim 50 having a central fuel tube extending along the axis through the collector. 52. The burner assembly of claim 51, wherein the opening end of the collector comprises at least three opening members and the outlet of the venturi tube is connected to each opening member, the opening members being arranged to extend in series around the central fuel tube. 23. The burner assembly of claim 22, wherein the collector is elongated and has a central axis extending between the tips of the collector. 54. The burner assembly of claim 53, comprising a central fuel tube extending through the collector and along the axis. 55. The burner assembly of claim 54, wherein the injection end of the collector comprises at least six openings and the outlet of the venturi tube is connected to each opening, respectively, wherein the openings are arranged to extend in series around the central fuel tube. 50. The burner assembly of claim 49, wherein the central fuel tube extends through the burner tip and has a downstream end projecting through an opening positioned centrally at the downstream end of the burner tip. 59. The burner assembly of claim 56, further comprising a fuel nozzle at a downstream end of the central fuel tube. 53. The burner assembly of claim 52, wherein the central fuel tube has a downstream end extending through the burner tip and protruding through an opening positioned centrally at the downstream end of the burner tip. 59. The burner assembly of claim 58, further comprising a fuel nozzle at a downstream end of the central fuel tube. 56. The burner assembly of claim 55, wherein the central fuel tube extends through the burner tip and has a downstream end projecting through an opening positioned centrally at the downstream end of the burner tip. 61. The burner assembly of claim 60, further comprising a fuel nozzle at a downstream end of the central fuel tube. 59. The apparatus of claim 56, wherein the tip is elongated in shape and adapted and arranged to direct the single mixed flow into the zone and out of the tip in a generally radial direction with respect to the longitudinal axis of the tip. Burner assembly. 63. The burner assembly of claim 62, wherein the tip is adapted and arranged to produce a round and flat flame surrounding the tip. 59. The burner of claim 56, wherein the tip is elongated in shape and adapted and arranged to direct the single mixed flow into the zone and out of the tip as a whole about the longitudinal axis of the tip. Assembly. 65. The burner assembly of claim 64, wherein the tip is adapted and arranged to produce a cylindrical flame extending along the axis. 59. The device of claim 58, wherein the tip is elongated in shape and adapted and arranged to direct the single mixed flow into the zone and out of the tip in a generally radial direction with respect to the longitudinal axis of the tip. Burner assembly. 67. The burner assembly of claim 66, wherein the tip is adapted and arranged to produce a round and flat flame surrounding the tip. 59. The burner of claim 58, wherein the tip is elongated in shape and adapted and arranged to direct the single mixed flow into the zone and out of the tip as a whole relative to the longitudinal axis of the tip. Assembly. 69. The burner assembly of claim 68, wherein the tip is adapted and arranged to produce a cylindrical flame extending along the axis. 61. The apparatus of claim 60, wherein the tip is elongated in shape and adapted and arranged to direct the single mixed flow into the zone and out of the tip in a generally radial direction with respect to the longitudinal axis of the tip. Burner assembly. 71. The burner assembly of claim 70, wherein the tip is adapted and arranged to produce a round and flat flame surrounding the tip. 61. The burner of claim 60, wherein the tip is elongated in shape and adapted and arranged to direct the single mixed flow into the zone and out of the tip as a whole about the longitudinal axis of the tip. Assembly. 73. The burner assembly of claim 72, wherein the tip is adapted and arranged to produce a cylindrical flame extending along the axis. 64. The burner assembly of claim 63, wherein the fuel nozzle is adapted and arranged to supply a second fuel to the combustion zone. 68. The burner assembly of claim 67, wherein the fuel nozzle is adapted and arranged to supply a second fuel to the combustion zone. 72. The burner assembly of claim 71, wherein the fuel nozzle is adapted and arranged to supply a second fuel to the combustion zone. 66. The burner assembly of claim 65, wherein the fuel nozzle is adapted and arranged to provide a continuous flame in position in a region axially spaced from the downstream end of the tip. 78. The burner assembly of claim 77, wherein said location is sufficiently spaced from said downstream end in said zone such that the rate of single mixed flow directed out of the tip adjacent to the fuel nozzle is not faster than the flame holding speed. 70. The burner assembly of claim 69, wherein the fuel nozzle is adapted and arranged to provide a continuous flame in position in a region axially spaced from the downstream end of the tip. 80. The burner assembly of claim 79, wherein said position is sufficiently spaced apart from said downstream end in said zone such that the rate of monomixed flow directed outside of the tip adjacent the fuel nozzle is not faster than the flame holding speed. 74. The burner assembly of claim 73, wherein the fuel nozzle is adapted and arranged to provide a continuous flame in position in a region axially spaced from the downstream end of the tip. 84. The burner assembly of claim 81, wherein said location is sufficiently spaced from said downstream end in said zone such that the rate of unitary flow directed outside of the tip adjacent the fuel nozzle is not faster than the flame holding speed. An elongated burner conduit having an injection end and an outlet end spaced apart, wherein the conduit is a burner tube structure adapted and arranged to direct the gas mixture of fluid fuel and oxygen passing from the injection end to the discharge end; ; A combustion zone located at the distal end of the conduit, having a central axis and a downstream end spaced from the distal end of the conduit, receiving the mixture from the conduit and passing one or more clearances in the downstream end along the axis A burner tip adapted and arranged to orient the mixture into; A fuel tube having a downstream end extending in the region along the axis and protruding outward of the tip through the downstream end in the axial direction and spaced apart from the downstream end of the burner tip; Wherein the at least one gap is disposed around the fuel tube such that the mixture directed through the at least one gap into the combustion zone is entirely cylindrical in shape surrounding the fuel tube and downstream of the tip along the axis towards the downstream end of the fuel tube. An elongated central fuel tube extending outwardly; A fuel nozzle located on the downstream end of the fuel tube, within a zone sufficiently far from the downstream end of the burner tip allowing the mixture to expand after leaving the downstream end of the tip and to decelerate at a rate slower than the flame speed entering the fuel nozzle And a fuel nozzle positioned at the point. 84. The burner assembly of claim 83, wherein said mixture consists of a mixture of gaseous fuel and air and said burner tube structure includes a venturi tube that uses said gaseous fuel flow to direct air flow. 84. The apparatus of claim 83, wherein the mixture consists of a mixture of gaseous fuel and air and the burner tube structure includes a plurality of venturi tubes arranged for parallel flow, each venturi tube configured to direct the flow of air. A burner assembly adapted and arranged to use a flow of gaseous fuel to produce the mixture, such as a very sparse fuel mixture of fuel and air. 84. The burner assembly of claim 83, wherein said burner tip has a tip wall at said downstream end of said burner tip, said tip wall having a plurality of said clearances and a central opening for said fuel tube. A generally annular base with a central axis; Extending along the axis and having a first end mounted on the base and a second end spaced from the base, the second end positioned closer to the axis than the first end, Defining an area inside the tip adapted to receive a flow of a mixture of air and fluid fuel, the outside of the burner tip in a direction with a direction extending from the area and a vector extending along the axis. And a plurality of elongated, parallel and circumferentially spaced ribs that are longitudinally curved to define a plurality of curved slots allowing the mixture to flow into the combustion zone. 88. The burner tip of claim 87 having a crown connected to a second end of said rib. 89. The air flow of claim 88 wherein the crown comprises a plurality of discontinuities extending in the axial and radial directions aligned in each slot such that a mixture of air and fluid fuel flowing through the discontinuities flows through the slot. Burner tip having a more axial flow direction for the mixture of. 90. The burner tip of claim 89, wherein the discontinuity is positioned to create a mixing zone for preprocessing stepwise outside the combustion zone to thereby flow the mixture of air and fluid fuel. 89. The burner tip of claim 88, wherein the crown portion axially aligns a gas nozzle receiving an opening therein. At least two venturi tubes, each venturi tube having an inlet, a neck, and an outlet and adapted and arranged to induce a flow of the induced fluid through the induced fluid through each of the induced fluid and the induced fluid The mixture of the venturi tube cluster and the discharge from the outlet; With an upstream end arranged and connected in fluid communication with the outlet of the venturi tube, each mixture of induced fluid and induced fluid is gathered and mixed to provide a single mixing flow of the fluids, and the burner tip is A collector configured to be in communication with the fluid at the distal end of the collector and to receive the single mixed flow of fluids from the collector and to distribute the single mixed flow into a combustion zone; A burner assembly having a burner tip of claim 87 and a composite venturi tube structure positioned downstream. 93. The composite venturi tube cluster of claim 92, wherein said single mixed flow of fluids comprises fluid fuel and air. 95. The composite ventilator cluster of claim 93, wherein said monomixed flow of fluids comprises a very sparse fuel mixture of fluid fuel and air. Separating the first fluid in at least two separate flow sections; Passing the first fluid through each separation flow section through each venturi tube to create a separate mixture of the induced material and the induced fluid to direct the flow of the induced material in each flow section. And; Mixing each separate mixture to form a mixture of said induced fluid and said induced material containing said derived material at a higher concentration than is possible in the total amount of said induced fluid passing through a single venturi tube; and However, the method of increasing the capacity of the venturi tube device to induce the flow of the material induced in the guide fluid when the flow of the guide fluid passes through the device. 95. The method of claim 95, wherein the draw fluid is separated in at least three separate flow sections. 95. The method of claim 95, wherein the draw fluid is separated in at least six separate flow sections. 96. The method of claim 95, wherein the induction fluid is gas fuel. 99. The method of claim 98, wherein said derived material is air. Separating the induction fluid in at least two separate flow sections; Passing each of the induction fluids through each separation flow portion through each venturi tube to create a separate mixture of the induced material and the induction fluid, thereby inducing the flow of the induced material in each of the flow portions; ; Mixing each separate mixture to produce a mixture of the induced fluid and the induced material containing the induced material at a higher concentration than is possible in the total amount of the induced fluid passing through a single venturi tube of equal length Including; but reducing the length of the modified venturi tube device to induce the flow of the material induced in the induction fluid when the flow of the induction fluid passes through the device. Having an inlet, a neck, and an outlet, and operable to induce a flow of the induced material as it passes through it, providing at least two venturi tubes producing a respective mixture of the induced material and the induced fluid; Discharging the mixture from the outlet; The first venturi tube is passed through the first inducing tube to induce a flow of the first induced substance and to produce a first mixture consisting of the first inducing fluid and the first inducing substance. Discharging said first mixture from an outlet; To induce the flow of the induced second material and pass the second induction fluid through the second venturi tube to produce a second mixture of the second induction fluid and the induced second material. Discharging said second mixture from an outlet; Collecting and mixing the first and second mixtures to provide a single mixture flow of fluid and material. Having an inlet, a neck and an outlet, and operable to induce the flow of the induced fluid as it passes through it, providing at least two venturi tubes producing a respective mixture of the induced fluid and the induced fluid Discharging the mixture from the outlet; To induce the flow of the induced first fluid and to pass the first induction fluid through the first venturi tube to produce a first mixture consisting of the first induction fluid and the induced first fluid. Discharging said first mixture from an outlet; To induce the flow of the induced second fluid and to pass the second induction fluid through the second venturi tube to produce a second mixture consisting of the second induction fluid and the induced second fluid. Discharging said second mixture from an outlet; Collecting and mixing the first and second mixtures to provide a single combustible mixture flow of the fluid; wherein the burner is provided in a venturi tube device for supplying a combustible mixture to a burner nozzle. 103. The method of claim 102, wherein the first and second induction fluids are each gaseous fuel. 109. The method of claim 103, wherein the induced first and second fluids are each air. 109. The method of claim 103, wherein the induced first fluid is air and the induced second fluid is recycled flue gas. 103. The burner of claim 102, wherein one of the induced fluids is a diluent. 107. The burner of claim 106, wherein the diluent is vapor. 107. The burner of claim 106, wherein the diluent is nitrogen. Delivering a flow of a combustible mixture of fuel and air to the combustion zone at a point where the flame speed of the mixture from the nozzle is slower than the speed of the mixture, such as the mixture leaving the nozzle; Expanding the mixture to allow a decrease at a rate no faster than the flame rate; Igniting a mixture after said rate is no faster than said flame rate already achieved. 109. The method of claim 109, wherein the mixture is a very lean fuel. 107. The method of claim 104, further comprising: expanding the mixing flow to allow deceleration at a rate no faster than the flame speed; Igniting the mixture after the rate is no faster than the flame speed already achieved, wherein the single combustible mixture flow of the fluid is a lean fuel and burns at a rate above the flame rate of the mixture. How to get to the zone. The composite venturi tube structure according to claim 1, wherein the substance is a fluid. The composite venturi tube structure according to claim 1, wherein the substance is a fluidized solid. 97. The method of claim 95, wherein the substance is a fluid. 97. The method of claim 95, wherein said substance is a fluidized solid. 101. The method of claim 100, wherein said substance is in fluid. 101. The method of claim 100, wherein said substance is a fluidized solid. 102. The method of claim 101, wherein said substance is in fluid. 102. The method of claim 101, wherein said substance is a fluidized solid. 40. The burner assembly of claim 39, wherein said diluent is carbon dioxide. 49. The burner assembly of claim 48, wherein the upstream tip of the central fuel tube is adapted to connect to a source of material. 49. The burner assembly of claim 48, wherein the upstream end of the central fuel tube is adapted to connect to a premixed source of air and fuel. 124. The burner assembly of claim 122, wherein said burner assembly includes a venturi tube connected to said upstream end of a central fuel tube. 123. The burner assembly of claim 122, wherein the burner assembly includes a multiventuri tube cluster connected to the upstream end of a central fuel tube. 55. The burner assembly of claim 54, wherein the upstream end of the central fuel tube is adapted to be connected to a fuel source. 55. The burner assembly of claim 54, wherein said upstream end of said central fuel tube is adapted to connect to a premixed source of air and fuel. 129. The burner assembly of claim 126, wherein said burner assembly includes a venturi tube connected to said upstream end of a central fuel tube. 126. The burner assembly of claim 126, wherein the burner assembly includes a multiple venturi tube cluster connected to the upstream end of a central fuel tube. The composite venturi tube structure according to claim 1, wherein the collector is elongated and has a central axis extending between the tips of the collector. 131. The composite venturi tube structure of claim 129, having a central tube extending along the axis through the collector. 133. The composite venturi tube structure according to claim 130, wherein the structure has a venturi tube connected to an upstream end of the central tube. 133. The composite venturi tube structure of claim 130, wherein the structure has multiple venturi tube clusters connected upstream of the central tube. And a first and second venturi tube cluster array, each arrangement comprising at least two venturi tubes, each venturi tube having an inlet, a neck, and an outlet through which an induced fluid is introduced. A venturi tube cluster adapted and arranged to induce a flow of material, wherein each mixture of the induced material and the induced fluid is discharged from the outlet; An injection stage is connected and arranged in fluid communication with the outlet of the venturi tube, whereby each mixture of induced material and induced fluid discharged from the outlet is gathered and mixed to provide a single mixing flow of the fluid and material. And venturi tubes of the first venturi tube cluster are spaced apart and the collectors thereof are annular so as to provide a central space, and the second cluster array is disposed in the central space.