US20260016157A1

US20260016157A1 - Extended orifice for a premixed burner

Info

Publication number: US20260016157A1
Application number: US18/768,505
Authority: US
Inventors: Joeb M. Woodring; Donald W. Cox; Zachery J. Heisler
Original assignee: Accutemp
Current assignee: Accutemp
Priority date: 2024-07-10
Filing date: 2024-07-10
Publication date: 2026-01-15

Abstract

An extended orifice for a premixed burner system is provided, comprising: an inlet section configured to couple to a fuel supply line, the inlet section including an inlet opening; a central body; an outlet section configured to couple to a manifold of a burner tube, the outlet section including a metering orifice; a central bore extending through the inlet section, the central body and the outlet section between the inlet opening and the metering orifice; and an extended tube extending from the outlet section, the extended tube having a tube wall that defines a bore, the bore extending between the metering orifice and an outlet opening at a distal end of the extended tube.

Description

TECHNICAL FIELD

The present disclosure is directed generally to premixed combustion burners, and more particularly to orifices for delivery of fuel into an oxidizer flow stream of a combustion burner.

BACKGROUND

In premixed combustion burners, even distribution of the fuel within the oxidizer flow is critical for producing even, completely combusting flames. In typical designs, fuel is introduced via an orifice oriented perpendicular to an oxidizer flow stream that is significantly higher in velocity as compared to the fuel stream. This velocity disparity causes the fuel stream to be relatively unaffected by lateral diffusion and to remain in largely the same radial location within the newly combined fuel-oxidizer flow. This results in poor mixing of the fuel within the oxidizer flow stream, and thus uneven combustion farther downstream.
It is common to use some sort of protrusion, deflector, or swirler in the combined fuel-oxidizer flow stream to encourage mixing for a more uniform fuel distribution. This, however, is disruptive to the fuel-oxidizer flow stream (or bulk flow) and can reduce performance of the burner and the flow supplying equipment. In some other premixed burner systems, the orifice is mounted on an extended feed tube and oriented to deliver fuel in a direction parallel and opposite to the oxidizer flow stream. This may significantly reduce performance of the orifice due to the fuel flow needing to overcome the counter flow of the oxidizer flow stream. In still other premixed burner systems, a plurality of fuel orifices may introduce fuel into the oxidizer stream at multiple circumferential locations, and perhaps at angles to the bulk flow other than parallel or perpendicular. This method increases complexity by requiring additional fuel supply lines and connection joints between components.
Thus, there exists a need to provide an orifice for delivery of fuel into an oxidizer flow stream of a premixed burner system in a simple, cost-efficient manner that enhances mixing of the fuel with the oxidizer flow stream to provide even combustion without undue disruption to the fuel-oxidizer flow stream.

SUMMARY

According to one embodiment, the present disclosure provides an extended orifice for a premixed burner system, comprising: an inlet section configured to couple to a fuel supply line, the inlet section including an inlet opening; a central body; an outlet section configured to couple to a manifold of a burner tube, the outlet section including a metering orifice; a central bore extending through the inlet section, the central body and the outlet section between the inlet opening and the metering orifice; and an extended tube extending from the outlet section, the extended tube having a tube wall that defines a bore, the bore extending between the metering orifice and an outlet opening at a distal end of the extended tube. In one aspect of this embodiment, the extended tube has a length such that the outlet opening at the distal end is positioned adjacent a central longitudinal axis of the burner tube when the extended orifice is coupled to the manifold of the burner tube. In another aspect, the inlet section includes external threads configured to mate with internal threads of the manifold. In another aspect, the inlet section includes a conical surface extending between the inlet opening and the central bore. In a variant of this aspect, the conical surface defines a radial cross-section that decreases with distance from the inlet opening. In another aspect, the bore of the extended tube has a substantially circular radial diameter. In another aspect, a radial diameter of the bore of the extended tube is greater than a radial diameter of the metering orifice.
In another embodiment, the present disclosure provides an extended orifice for a premixed burner system, comprising: an orifice having an inlet section configured to mate with a fuel supply line, an outlet section having an exit opening, and a metering orifice between the inlet section and the outlet section; and an extended orifice adapter, comprising: a head having an orifice opening configured to receive the outlet section of the orifice; a threaded end configured to mate with a manifold of a burner tube and a delivery opening in flow communication with the orifice opening; and an extended tube defining a cylindrical bore extending between an inlet opening at a proximal end of the extended tube and an outlet opening at a distal end of the extended tube, the inlet opening being in flow communication with the delivery opening of the threaded end. In one aspect of this embodiment, the extended orifice adapter further comprises a disk having a central opening, the disk being coupled to an outer end of the threaded end and the central opening being coupled to the proximal end of the extended tube such that the cylindrical bore is in flow communication with the central opening. In a variant of this aspect, the disk is welded to the outer end and the proximal end of the extended tube is welded to the central opening of the disk. In another aspect, the threaded end of the extended orifice adapter includes external threads configured to mate with internal threads of the manifold. In another aspect, the head includes internal threads configured to mate with external threads on the outlet section of the orifice. In yet another aspect, the extended tube has a length such that the outlet opening at the distal end is positioned adjacent a central longitudinal axis of the burner tube when the extended orifice is coupled to the manifold of the burner tube. In another aspect of this embodiment, the head includes a plurality of faces configured to accommodate a wrench to tighten the extended orifice adapter into the manifold.
In yet another embodiment, the present disclosure provides a premixed burner system, comprising: a burner tube including a tube wall defining a flow bore and a manifold having an orifice opening and a fuel opening in flow communication with the flow bore; and an extended orifice, comprising: an inlet section configured to couple to a fuel supply line, the inlet section including an inlet opening; an outlet section configured to couple to the manifold of the burner tube, the outlet section including a metering orifice; a central bore extending through the inlet section and the outlet section between the inlet opening and the metering orifice; and an extended tube extending from the outlet section, the extended tube having a tube wall that defines a bore, the bore extending between the metering orifice and an outlet opening at a distal end of the extended tube; wherein, when the extended orifice is coupled to the manifold of the burner tube, the outlet opening of the extended tube is positioned adjacent a central longitudinal axis of the burner tube to deliver fuel from the extended orifice into an oxidizer flow through the burner tube at a location adjacent the central longitudinal axis of the burner tube. In one aspect of this embodiment, the bore of the extended tube has a radial diameter that is greater than a radial diameter of the metering orifice. In another aspect, a longitudinal axis of the extended orifice is substantially perpendicular to the central longitudinal axis of the burner tube. In another aspect, the bore of the extended tube has a substantially circular radial cross-section. In yet another aspect, a longitudinal axis of the extended orifice forms an acute angle with the central longitudinal axis of the burner tube. In another aspect, a longitudinal axis of the extended orifice is one of above or below the central longitudinal axis of the burner tube. In still another aspect, the extended tube has a length that is based upon an expected oxidizer flow rate and an expected fuel flow rate.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a side, cross-sectional view of a conventional orifice;

FIG. 2 is a side, cross-sectional view of the orifice of FIG. 1 mounted to a burner tube;

FIG. 3 is a side, cross-sectional view of an extended orifice according to one embodiment of the present disclosure;

FIG. 4 is a side, cross-sectional view of the extended orifice of FIG. 3 mounted to a burner tube;

FIG. 5A is a side, cross-sectional view similar to FIG. 2 depicting the flow of fuel, oxidizer and a combination of fuel and oxidizer in a burner tube having the orifice of FIG. 1 mounted thereto;

FIG. 5B is a side, cross-sectional view similar to FIG. 4 depicting the flow of fuel, oxidizer and a combination of fuel and oxidizer in a burner tube having the extended orifice of FIG. 3 mounted thereto;

FIG. 6 is a perspective view of an extended orifice adapter according to one embodiment of the present disclosure;

FIG. 7 is a perspective, exploded view of the extended orifice adapter of FIG. 6 ;

FIG. 8 is a side, cross-sectional view of the extended orifice adapter of FIG. 6 ;

FIG. 9 is a side, cross-sectional view of the extended orifice of FIG. 3 mounted to a burner tube at an acute angle relative to a longitudinal axis of the burner tube; and

FIG. 10 is a side, cross-sectional view of the extended orifice of FIG. 3 mounted to a burner tube such that a central longitudinal axis of the extended orifice does not intersect a longitudinal axis of the burner tube.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates an embodiment of the invention, the embodiment disclosed below is not intended to be exhaustive or to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiments illustrated in the drawings, which are described below. The embodiments disclosed below are not intended to be exhaustive or limit the disclosure to the precise form disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may utilize their teachings. It will be understood that no limitation of the scope of the disclosure is thereby intended. The disclosure includes any alterations and further modifications in the illustrative devices and described methods and further applications of the principles of the disclosure which would normally occur to one skilled in the art to which the disclosure relates.
Referring now to FIG. 1 , a conventional orifice 10 for a premixed combustion burner is shown. The orifice 10 generally includes an outlet section 12, a central body 14, and an inlet section 16. A central bore 18 extends from a fuel opening 17 of the inlet section 16, through the central body 14 and to the outlet section 12. The outlet section 12 includes a distal end 20, an exit opening 22 in the distal end 20, a metering orifice 26 in flow communication with the exit opening 22, and an inlet opening 28 in flow communication with the metering orifice 26 and the central bore 18. The exit opening 22 includes a conical surface 24 defining a radial cross-section of the exit opening 22 that increases with distance from the metering orifice 26 to the distal end 20 of the outlet section 12. The inlet opening 28 includes a conical surface 30 defining a radial cross-section of the inlet opening 28 that decreases with distance from the central bore 18 to the metering orifice 26. The outlet section 12 also includes external threads 32 for connecting the orifice 10 to a burner tube as is described below. The inlet section 16 also includes external threads 34 for connecting a fuel supply line (not shown) to the orifice 10.
In operation, pressurized fuel is delivered from a fuel supply line to the orifice 10 at the fuel opening 17. The fuel flows through the central bore 18 into the inlet opening 28 of the outlet section 12 where the conical surface 30 compresses the fuel. The compressed fuel flows through the metering orifice 26 and into the exit opening 22 where it expands and exits the orifice 10 through the exit opening 22 at the distal end 20 to mix with an oxidizer flow stream of the burner tube.
FIG. 2 depicts the conventional orifice 10 of FIG. 1 connected to a burner tube 40. As shown, the burner tube 40 includes a substantially cylindrical tube wall 42 defining a flow bore 44. A manifold 46 is formed in the tube wall 42 for receiving fuel from the orifice 10 as is further described below. The manifold 46 includes an opening 48 with internal threads 50. The opening 48 is in flow communication with a fuel opening 68, which is in flow communication with the flow bore 44 of the burner tube 40.
In certain applications, the conventional orifice 10 is coupled to the burner tube 40 using an adapter 52. As shown in FIG. 2 , the adapter 52 in certain embodiments includes a head 54 and a threaded end 56. The head includes an orifice opening 58 with internal threads 60. The orifice opening 58 is in flow communication with a delivery opening 62 formed through the threaded end 56 of the adapter 52. The orifice 10 is connected to the adapter 52 by threading the external threads 32 of the outlet section 12 of the orifice 10 into the internal threads 60 of the head 54 of the adapter 52. The adapter 52 is connected to the burner tube 40 by threading the threaded end 56 of the adapter 52 into the internal threads 50 of the opening 48 of the manifold 46. Finally, a fitting (not shown) of a fuel supply line (not shown) is threaded onto the external threads 34 of the inlet section 16 of the orifice 10.
Referring to FIGS. 1 and 2 , as indicated above, pressurized fuel (represented by arrow 38) is delivered from the fuel supply line (not shown) into the fuel opening 17 of the orifice 10. The fuel flows through the central bore 18 and the metering orifice 26 and exits the orifice 10 at the distal end 20. The fuel then passes through the delivery opening 62 of the adapter 52 and into the fuel opening 68 of the burner tube 40 where the fuel begins mixing with the oxidizer flow (represented by arrow 64). The combined flow of fuel and oxidizer is represented by arrow 66.
Referring now to FIG. 3 , an extended orifice 70 according to one embodiment of the present disclosure is shown. The extended orifice 70 generally includes an inlet section 98, a central body 90, an outlet section 72 and an extended tube 74. The inlet section 98 includes a substantially cylindrical inlet wall 101 with an inlet opening 104 at an inlet end 102. The inlet opening 104 is defined by a conical surface 106 of the interior of the inlet wall 101. The conical surface 106 of the inlet opening 104 defines a radial cross-section that decreases in diameter with distance from the inlet end 102. The conical surface 106 transitions to a central bore 108 extending through the inlet section 98, the central body 90 and a portion of the outlet section 72 of the extended orifice 70. The inlet wall 101 of the inlet section 98 also includes external threads 100.
The inlet section 98 transitions to the central body 90 at a conical transition 96 of the central body 90. The central body 90 includes an outer surface 92 extending from the conical transition 96 in substantially parallel relationship with the central bore 108. The central body 90 further includes a reduced diameter annular transition 94 connecting the central body 90 to the outlet section 72.
The outlet section 72 of the extended orifice 70 includes an inlet opening 84 in flow communication with the central bore 108. The inlet opening 84 tapers from a diameter substantially corresponding to the diameter of the central bore 108 to a diameter substantially corresponding to a diameter of a metering orifice 82 of the outlet section 72. The taper of the inlet opening 84 is defined by a conical surface 86 of the outlet section 72 that defines a radial cross-section that decreases in diameter with distance from the central bore 108 to the metering orifice 82. The metering orifice 82 is in flow communication with the central bore 108 via the inlet opening 84. The metering orifice 82 is also in flow communication with an exit opening 78 of the outlet section 72 that increases in diameter from a diameter substantially corresponding to the diameter of the metering orifice 82 to a larger diameter substantially corresponding to a diameter of a cylindrical bore 114 of the extended tube 74. The diameter change from the diameter of the metering orifice 82 to the diameter of the cylindrical bore 114 is defined by a conical surface 80 of the outlet section 72. The outlet section 72 also includes external threads 88 and a conical transition 118 to the extended tube 74.
The extended tube 74 includes a tube wall 116 that defines the cylindrical bore 114 mentioned above. As indicated, the cylindrical bore 114 extends from and is in flow communication with the exit opening 78 of the outlet section 72. The cylindrical bore 114 terminates at an outlet opening 112 at a distal end 76 of the extended tube 74. The extended orifice 70 of this embodiment includes a central longitudinal axis 110 that extends through the center of the inlet opening 104, the central bore 108, the inlet opening 84, the metering orifice 82, the exit opening 78, the cylindrical bore 114 and the outlet opening 112.
As should be apparent from the foregoing, pressurized fuel (represented by arrow 38) is delivered by a fuel supply line (not shown) into the inlet opening 104 of the extended orifice 70. The fuel supply line (not shown) is coupled to extended orifice 70 by threading a fitting (not shown) of the fuel supply line onto the external threads 100 of the inlet section 98 of the extended orifice 70. The fuel flows through the central bore 108 and is compressed by the conical surface 86 of the inlet opening 84. The fuel passes through the metering orifice 82 and expands as it exits the metering orifice 82 into the exit opening 78. The fuel then flows through the cylindrical bore 114 of the extended tube 74 and exits the extended orifice 70 through the outlet opening 112 of the extended tube 74.
FIG. 4 depicts the extended orifice 70 according to the embodiment depicted in FIG. 3 connected to a burner tube 40, thereby forming a premixed burner system 71. The burner tube 40 is substantially the same as that described above with reference to FIG. 2 . The burner tube 40 includes a substantially cylindrical tube wall 42 defining a flow bore 44. A manifold 46 is formed in the tube wall 42 for receiving fuel from the extended orifice 70 as is further described below. The manifold 46 includes an opening 48 with internal threads 50. The opening 48 is in flow communication with a fuel opening 68, which is in flow communication with the flow bore 44 of the burner tube 40.
The extended orifice 70 is connected to the manifold 46 of the burner tube 40 by threading the external threads 88 of the outlet section 72 of the extended orifice 70 into the internal threads 50 of the opening 48 of the manifold 46. Referring to FIGS. 3 and 4 , as indicated above, a pressurized fuel flow (represented by arrow 38) is delivered from the fuel supply line into the inlet opening 104 of the extended orifice 70. The fuel flows through the central bore 108 and the metering orifice 82 and exits the extended orifice 70 through the outlet opening 112 of the extended tube 74. The fuel is routed through the fuel opening 68 of the burner tube 40 by the extended tube 74. As best shown in FIG. 4 , the fuel is introduced into the oxidizer flow (represented by arrow 64) at a location near a central, longitudinal axis 103 of the flow bore 44 of the burner tube 40. The fuel combines with the oxidizer to form a combined fuel/oxidizer flow represented by arrow 66.
The configuration of the extended orifice 70, and in particular the extended tube 74, extends into the oxidizer flow 64 and shields the fuel flow 38 from the oxidizer flow 64 until the fuel flow 38 exits the extended tube 74. The length of the extended tube 74 is calculated to allow the fuel flow 38 to be placed at a desired radial position within the oxidizer flow 64. As would be understood by a skilled artisan, the length of the extended tube 74 is not simply calculated to place the outlet opening 112 at a desired radial position within the flow bore 44 of the burner tube 40. The length is calculated based upon the combined vectorized velocities of the fuel flow 38 and the oxidizer flow 64 and is thus dependent upon the expected oxidizer flow 64 rate and the expected fuel flow 38 rate. Typically, the oxidizer flow 64 rate is measured in terms of volume per time unit and the fuel flow 38 rate is measured in terms of pressure units. The outer diameter of the extended tube 74 is calculated to minimize the disturbance to the expected oxidizer flow 64. It should further be understood that the inner diameter of the extended tube 74 (i.e., the diameter of the cylindrical bore 114) is larger than the diameter of the metering orifice 82 to prevent unnecessary flow disturbance of the fuel flow 38 and maintain the performance of the extended orifice 70.
Referring now to FIGS. 5A and 5B, a comparison of the mixing of fuel and oxidizer using a conventional orifice 10 and an extended orifice 70 according to one embodiment of the present disclosure is shown. In FIG. 5A a conventional orifice 10 is coupled to the burner tube 40 in the manner described above with reference to FIG. 2 . The pressurized fuel is shown in black and labeled 120. As shown, the fuel 120 exits the exit opening 22 at the distal end 20 of the outlet section 12 of the orifice 10 and flows into the fuel opening 68 of the burner tube 40. The oxidizer flow is shown in light gray and labeled 122. As shown, as the fuel 120 exits the fuel opening 68 it begins mixing with the oxidizer flow 122 and the various shades of gray labeled 124 represent a mixture of fuel 120 and oxidizer flow 122. This mixture 124 flows primarily along one side of the burner tube 40 (i.e., the left side as shown in the drawing) and the composition of the mixture 124 increasingly consists of fuel 120 with radial distance from the longitudinal axis 103 of the burner tube 40. As such, the mixture 124 is substantially non-uniform across the radial diameter of the burner tube 40, which results in undesirable and incomplete combustion.
Referring now to FIG. 5B, an extended orifice 70 according to one embodiment of the present disclosure is coupled to the burner tube 40 in the manner described above with reference to FIG. 4 . The pressurized fuel is shown in black and labeled 120. As shown, the fuel 120 exits the outlet opening 112 at the distal end 76 of the extended tube 74 of the extended orifice 70. The fuel 120 is introduced into the oxidizer flow (shown in light gray and labeled 122) near the longitudinal axis 103 of the burner tube 40. As shown, as the fuel 120 exits the outlet opening 112 it begins mixing with the oxidizer flow 122 and the various shades of gray labeled 124 represent a mixture of fuel 120 and oxidizer flow 122. This mixture 124 disperses substantially uniformly across the radial diameter of the burner tube 40 and thereby provides improved combustion.
Referring now to FIGS. 6 through 8 , an alternative approach for achieving enhanced mixing of the fuel and oxidizer flows is shown. In this approach, an extended orifice adapter 130 is provided for use with a conventional orifice 10. The combination of the extended orifice adapter 130 and the conventional orifice 10 may be referred to herein as “an extended orifice.” The adapter 130 generally includes a head 132, a threaded end 134, a disk 146 and an extended tube 150. The head 132 and the threaded end 134 are substantially similar to the head 54 and the threaded end 56 of the adapter 52 depicted in FIG. 2 and are configured for mounting to the manifold 46 of the burner tube 40 as described above. The head 132 includes a plurality of faces 160 for accommodating use of a wrench to tighten the adapter 130 into the manifold 46. The head 132 further includes an orifice opening 136 and internal threads 138 configured to mate with the external threads 32 of the outlet section 12 of the orifice 10.
The threaded end 134 includes external threads 140 which are configured to mate with the internal threads 50 of the manifold 46 of the burner tube 40. The threaded end 134 also includes a delivery opening 142 which is in flow communication with the orifice opening 136. The delivery opening 142 terminates at an outer end 144 of the threaded end 134. As best shown in FIG. 7 , the disk 146 is shaped like a washer and includes a central opening 148. As shown in FIGS. 6 and 8 , when the adapter 130 is fully assembled, the disk 146 is attached (e.g., by welding) to the outer end 144 of the threaded end 134. The extended tube 150 in this embodiment is simply an elongated cylindrical tube having a tube wall 152 forming a cylindrical bore 158 and having a proximal end 153 forming an inlet opening 155 and a distal end 154 forming an outlet opening 156. When the adapter 130 is fully assembled, the proximal end 153 of the extended tube 150 is attached (e.g., by welding) to the central opening 148 of the disk 146. In this manner, the cylindrical bore 158 of the extended tube 150 is in flow communication with the delivery opening 142 of the threaded end 134 of the adapter 130.
In use, the adapter 130 is mounted to the manifold 46 of the burner tube 40 in the manner described above with reference to the adapter 52. An orifice 10 is threaded into the orifice opening 136 of the adapter 130 and a fitting (not shown) of a fuel supply line (not shown) is threaded onto the external threads 34 of the inlet section 16 of the orifice 10. Pressurized fuel provided from the fuel supply line flows through the orifice 10 in the manner described above, through the orifice opening 136 of the head 132 of the adapter 130, through the delivery opening 142 of the threaded end 134 of the adapter 130, into the inlet opening 155 of the extended tube 150, through the cylindrical bore 158 and finally out the outlet opening 156 of the extended tube 150.
Referring now to FIG. 9 , it should be understood that the extended orifice 70 or the extended orifice adapter 130 may be mounted to a manifold 46 of a burner tube 40 that orients the extended tube 74, 150 at an angle relative to the longitudinal axis 103 of the burner tube 40 other than perpendicular. As shown, in this example the central longitudinal axis 110 of the extended orifice 70 is positioned at an acute angle 172 relative to the longitudinal axis 103 of the burner tube 40. It should be understood that in other embodiments, the angle may be less than or greater than the angle 172 shown. In still other embodiments, the angle may be an obtuse angle such that the fuel flow initially flows partially against the direction of the oxidizer flow.
Referring now to FIG. 10 , it should be understood that the extended orifice 70 or the extended orifice adapter 130 may be mounted to a manifold 46 of a burner tube 40 that orients the extended tube 74, 150 such that the central longitudinal axis 110 of the extended orifice 70 (or extended orifice adapter 130) does not intersect the longitudinal axis 103 of the burner tube 40. In the example shown in FIG. 10 , the central longitudinal axis 110 of the extended orifice is positioned below the longitudinal axis 103 of the burner tube 40. In other embodiments, the manifold 46 may be configured to position the central longitudinal axis 110 of the extended orifice 70 above the longitudinal axis 103 of the burner tube 40. In still other embodiments, the distance between the central longitudinal axis 110 of the extended orifice 70 and the longitudinal axis 103 of the burner tube 40 may be greater or less than that shown in FIG. 10 .
The above descriptions all reference terms that imply circular cross sections of the extended tube 74 and the burner tube 40, such as “circumferential,” “axis,” “axial,” and “radial.” However, it should be understood that the extended tube 74, the fuel flow stream, the burner tube 40, the oxidizer flow stream, the combined fuel-oxidizer flow stream, or any combination of those may be a shape other than circular in cross-section, such as oval, rectangular, n-sided polygon, irregular or amorphous shapes, tapered or non-uniform cross-sections, etc.
Any directional references used with respect to any of the figures, such as right or left, up or down, or top or bottom, are intended for convenience of description, and do not limit the present disclosure or any of its components to any particular positional or spatial orientation. Additionally, any reference to rotation in a clockwise direction or a counter-clockwise direction is simply illustrative. Any such rotation may be implemented in the reverse direction as that described herein.
Although the foregoing text sets forth a detailed description of embodiments of the disclosure, it should be understood that the legal scope of the invention is defined by the words of the claims set forth at the end of this patent and equivalents. The detailed description is to be construed as exemplary only and does not describe every possible embodiment. Numerous alternative embodiments may be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims.
The following additional considerations apply to the foregoing description. Throughout this specification, plural instances may implement components, operations, or structures described as a single instance. Although individual operations of one or more methods are illustrated and described as separate operations, one or more of the individual operations may be performed concurrently, and nothing requires that the operations be performed in the order illustrated. Structures and functionality presented as separate components in example configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements fall within the scope of the subject matter herein.
As used herein any reference to “one embodiment” or “an embodiment” means that a particular element, feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
Some embodiments may be described using the expression “coupled” and “connected” along with their derivatives. For example, some embodiments may be described using the term “coupled” to indicate that two or more elements are in direct physical or electrical contact. The term “coupled,” however, may also mean that two or more elements are not in direct contact with each other, but yet still co-operate or interact with each other. The embodiments are not limited in this context.
As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
In addition, use of the “a” or “an” are employed to describe elements and components of the embodiments herein. This is done merely for convenience and to give a general sense of the description. This description, and the claims that follow, should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.
The patent claims at the end of this patent application are not intended to be construed under 35 U.S.C. § 112 (f) unless traditional means-plus-function language is expressly recited, such as “means for” or “step for” language being explicitly recited in the claim(s).

Claims

What is claimed is:

1. An extended orifice for a premixed burner system, comprising:

an inlet section configured to couple to a fuel supply line, the inlet section including an inlet opening;

a central body;

an outlet section configured to couple to a manifold of a burner tube, the outlet section including a metering orifice;

a central bore extending through the inlet section, the central body and the outlet section between the inlet opening and the metering orifice; and

an extended tube extending from the outlet section, the extended tube having a tube wall that defines a bore, the bore extending between the metering orifice and an outlet opening at a distal end of the extended tube.

2. The extended orifice of claim 1, wherein the extended tube has a length such that the outlet opening at the distal end is positioned adjacent a central longitudinal axis of the burner tube when the extended orifice is coupled to the manifold of the burner tube.

3. The extended orifice of claim 1, wherein the inlet section includes external threads configured to mate with internal threads of the manifold.

4. The extended orifice of claim 1, wherein the inlet section includes a conical surface extending between the inlet opening and the central bore.

5. The extended orifice of claim 3, wherein the conical surface defines a radial cross-section that decreases with distance from the inlet opening.

6. The extended orifice of claim 1, wherein the bore of the extended tube has a substantially circular radial diameter.

7. The extended orifice of claim 1, wherein a radial diameter of the bore of the extended tube is greater than a radial diameter of the metering orifice.

8. An extended orifice for a premixed burner system, comprising:

an orifice having an inlet section configured to mate with a fuel supply line, an outlet section having an exit opening, and a metering orifice between the inlet section and the outlet section; and

an extended orifice adapter, comprising:

a head having an orifice opening configured to receive the outlet section of the orifice;

a threaded end configured to mate with a manifold of a burner tube and a delivery opening in flow communication with the orifice opening; and

an extended tube defining a cylindrical bore extending between an inlet opening at a proximal end of the extended tube and an outlet opening at a distal end of the extended tube, the inlet opening being in flow communication with the delivery opening of the threaded end.

9. The extended orifice of claim 8, wherein the extended orifice adapter further comprises a disk having a central opening, the disk being coupled to an outer end of the threaded end and the central opening being coupled to the proximal end of the extended tube such that the cylindrical bore is in flow communication with the central opening.

10. The extended orifice of claim 9, wherein the disk is welded to the outer end and the proximal end of the extended tube is welded to the central opening of the disk.

11. The extended orifice of claim 8, wherein the threaded end of the extended orifice adapter includes external threads configured to mate with internal threads of the manifold.

12. The extended orifice of claim 8, wherein the head includes internal threads configured to mate with external threads on the outlet section of the orifice.

13. The extended orifice of claim 8, wherein the extended tube has a length such that the outlet opening at the distal end is positioned adjacent a central longitudinal axis of the burner tube when the extended orifice is coupled to the manifold of the burner tube.

14. The extended orifice of claim 8, wherein the head includes a plurality of faces configured to accommodate a wrench to tighten the extended orifice adapter into the manifold.

15. A premixed burner system, comprising:

a burner tube including a tube wall defining a flow bore and a manifold having an orifice opening and a fuel opening in flow communication with the flow bore; and

an extended orifice, comprising:

an outlet section configured to couple to the manifold of the burner tube, the outlet section including a metering orifice;

a central bore extending through the inlet section and the outlet section between the inlet opening and the metering orifice; and

an extended tube extending from the outlet section, the extended tube having a tube wall that defines a bore, the bore extending between the metering orifice and an outlet opening at a distal end of the extended tube;

wherein, when the extended orifice is coupled to the manifold of the burner tube, the outlet opening of the extended tube is positioned adjacent a central longitudinal axis of the burner tube to deliver fuel from the extended orifice into an oxidizer flow through the burner tube at a location adjacent the central longitudinal axis of the burner tube.

16. The premixed burner system of claim 15, wherein the bore of the extended tube has a radial diameter that is greater than a radial diameter of the metering orifice.

17. The premixed burner system of claim 15, wherein a longitudinal axis of the extended orifice is substantially perpendicular to the central longitudinal axis of the burner tube.

18. The premixed burner system of claim 15, wherein the bore of the extended tube has a substantially circular radial cross-section.

19. The premixed burner system of claim 15, wherein a longitudinal axis of the extended orifice forms an acute angle with the central longitudinal axis of the burner tube.

20. The premixed burner system of claim 15, wherein a longitudinal axis of the extended orifice is one of above or below the central longitudinal axis of the burner tube.

21. The premixed burner system of claim 15, wherein the extended tube has a length that is based upon an expected oxidizer flow rate and an expected fuel flow rate.