US20230071567A1

US20230071567A1 - Bodies configured for use in radiant tubes

Info

Publication number: US20230071567A1
Application number: US17/929,668
Authority: US
Inventors: Bradley NAKANISHI; Pierre Gougeon; Thomas D. Briselden; Evgeniy E. Esjunin; Catherine Goulas
Original assignee: Saint Gobain Ceramics and Plastics Inc
Current assignee: Saint Gobain Ceramics and Plastics Inc
Priority date: 2021-09-03
Filing date: 2022-09-02
Publication date: 2023-03-09
Also published as: CN117957401A; WO2023034999A1

Abstract

A body to be installed into a radiant tube for reduction of pollutants, the body including a body having a tube shape including a length, an outer diameter and an inner diameter, the body further comprises a proximal surface, a terminal surface, and a circumferential surface extending between the proximal surface and terminal surface, and the body is configured to be disposed at an axial distance from a terminal end of a burner, wherein the axial distance (AD) is at least a 0.1% of the length of the body.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 63/260,902, filed Sep. 3, 2021, by Bradley NAKANISHI, et al., entitled “BODIES CONFIGURED FOR USE IN RADIANT TUBES,” which is assigned to the current assignee hereof and incorporated herein by reference in its entirety for all purposes.

FIELD OF THE DISCLOSURE

The present disclosure relates to bodies for use in or with radiant tubes.

BACKGROUND

Combustion of fossil fuels introduces emissions into the atmosphere, such as nitrogen oxides (NOx). NOx emissions arise from nitrogen present in the combustion air and from fuel-bound nitrogen in coal or fuel oil, for example. Conversion of fuel-bound nitrogen to NOx depends on the amount and reactivity of the nitrogen compounds in the fuel and the amount of oxygen in the combustion area. Conversion of atmospheric nitrogen, N₂, present in the combustion air to NOx is temperature-dependent; the greater the flame temperature in the combustion area, the greater the resultant NOx content in the emissions. Growing environmental concern is leading to even more stringent regulation of NOx emissions.
There exists a need to improve furnace systems to reduce pollutants and improve the efficiency of heat exchange.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure may be better understood, and its numerous features and advantages made apparent to those skilled in the art by referencing the accompanying drawings.

FIG. 1 includes an illustration of a system including a body and an exchanger body according to one embodiment.

FIGS. 2A-2E include illustrations of a body according to an embodiment.

FIGS. 3A-3F include illustrations of a positioning device according to an embodiment.

FIGS. 4A-4E include illustrations of an exchange body according to an embodiment.

DETAILED DESCRIPTION

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 features is not necessarily limited only to those features but may include other features not expressly listed or inherent to such process, method, article, or apparatus.
As used herein, and unless expressly stated to the contrary, “or” refers to an inclusive-or and not to an exclusive-or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).
Also, the use of “a” or “an” are employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description 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 present disclosure is directed to components that may be used in furnaces, such as radiant tubes and/or heat exchangers. The components herein can be adapted for use in any size or shape of radiant tubes, such as U or W tubes, including for example for steel annealing, coating, or heat treating furnaces. A particular use of the heat exchanger insert of the present disclosure can be for large diameter heat exchangers to recover waste energy.
A non-limiting embodiment of a system is provided in FIG. 1 . FIG. 1 includes a system 100 including a radiant tube 101 and a burner 103 at least partially disposed in the radiant tube. In one embodiment, the system 100 can include an optional body 105 disposed in the radiant tube and configured to reduce the content of pollutants. In another embodiment, the system 100 can include an exchange body 107 having multiple flowpaths for the exchange of heat between two or more different streams of fluids (e.g., gasses) flowing through the exchange body 107.
FIG. 2A includes a side-view illustration of a body 105 configured to be disposed in the radiant tube proximate to the burner 103 and configured to reduce the content of pollutants formed during combustion. FIG. 2B includes a cross-sectional illustration of the body 105 according to an embodiment. FIG. 2C includes an illustration of the body 105 and burner 103 according to an embodiment. According to one embodiment, the body 105 may reduce the content of pollutants (e.g., NOx) by at least 10%, such as at least 12% or at least 15% or at least 18% or at least 20% or at least 25% or at least 30% as compared to state-of-the-art systems that do not use such a body 105 or alternatively use a body made of a metal mesh material or have other less desirable configurations. In one non-limiting embodiment, the body 105 can reduce the content of pollutants by not greater than 100% or not greater than 80% or not greater than 60%. It will be appreciated that the reduction in the content of pollutants can be within a range including any of the minimum and maximum percentages noted above.
In one embodiment, the body 105 may have a generally tubular shape. The body 105 may have a length (L), an outer diameter (OD), and an inner diameter (ID). The outer diameter can be defined by the largest diameter value, which may include the extension of radial members from the body 105. The inner diameter can be defined by the smallest dimension within the central axial opening 207, which can be defined by an inner annular surface 209. The inner diameter can be the smallest dimension between any optional radial members within the central axial opening 207. In one embodiment, the body 105 can include a proximal surface 201, a terminal surface 203, and a circumferential surface 205 extending between the proximal surface 201 and terminal surface 203. In another embodiment, the body 105 can include a central axial opening that may extend for a full length (L) of the body 105.
According to one embodiment, the body 105 can be a monolithic body. In one particular embodiment, the body 105 can have a solid side wall surrounding the central axial opening. Such a configuration may be suitable to define and distinguish two discrete flow streams between the central axial opening 207 and a flowpath along the outside of the tube shape along the outer circumferential surface 205.
In one non-limiting embodiment, the body 105 can include a ceramic material. In one particular instance, the body may include an oxide, carbide, nitride, or any combination thereof. In one embodiment, the body may include a carbide, such as silicon carbide. In one particular embodiment, the body consists essentially of a ceramic, such as consisting essentially of a carbide, and more particularly, may consist essentially of silicon carbide.
In a further embodiment, the material of the body 105 may have a particular density that may facilitate improved manufacturing and/or operation. For example, the material of the body 105 may have an average density of at least 2.50 g/cm³, such as at least 2.55 g/cm³, or at least 2.57 g/cm³, or at least 2.60 g/cm³, or at least 2.70 g/cm³. In a further embodiment, the average density of the material of the body 105 may be not greater than 2.9 g/cm³, or not greater than 2.8 g/cm³, or not greater than 2.75 g/cm³. Moreover, the average density of the material of the body can be within a range including any of the minimum and maximum values noted above.
In a particular embodiment, the body of the heat exchanger component can be manufactured by a powder pressing process as, for example, described in U.S. Pat. No. 8,162,040, of which the entire disclosure is incorporated by reference herein. In another embodiment, the body can be formed through conventional powder or slurry manufacturing methods, including for example, but not limited to, mixing, casting, molding, pressing, drying, sintering, or any combinations thereof.
According to one embodiment, the body 105 can be configured to be disposed in a particular location relative to the burner. More particularly, as illustrated in FIG. 2C, the proximal end 201 of the body 105 may be disposed at a particular axial distance (AD) from a terminal end 211 of the burner, which may facilitate improved reduction of pollutants. In a more particular embodiment, through empirical studies, it has been found that controlling the relationship between the axial distance (AD) relative to the length (L) of the body 105 may be suitable for reducing pollutants. In one embodiment, the use of a body 105 having a solid wall as opposed to another construction (e.g., a mesh tube) may benefit from a particular spacing between the axial distance relative to the length of the body 105, which may be suitable to reduce pollutants. For example, in one non-limiting embodiment, the axial distance (AD) may be at least a 0.1% of the length (L) of the body 105 [(AD/L)×100%], such as at least 1% or at least 2% or at least 3% or at least 4% or at least 5% or at least 6% or at least 7% or at least 8% or at least 9% or at least 10% or at least 15% or at least 20% or at least 25% or at least 30% or at least 35% or at least 40% or at least 45% or at least 50% or at least 55% or at least 60% or at least 65% or at least 70% or at least 75% or at least 80% or at least 85% or at least 90% or at least 95% or at least 100%. In still another non-limiting embodiment, the axial distance may be not greater than 900% of the length of the body, such as not greater than 500% or not greater than 200% or not greater than 100% or not greater than 90% or not greater than 85% or not greater than 80% or not greater than 75% or not greater than 70% or not greater than 65% or not greater than 60% or not greater than 55% or not greater than 50% or not greater than 45% or not greater than 40% or not greater than 35%. In another non-limiting embodiment, the axial distance may be within a range of at least 0.1% and not greater than 900% of the length of the body 105. In another embodiment, it will be understood that the axial distance may be within a range between any percentage between at least 0.1% and not greater than 900% of the length of the body 105.
In another non-limiting embodiment, it has been found through some studies that it may be suitable to control the axial distance relative to a wall thickness of the body. The wall thickness can be defined as the difference between the outer diameter and inner diameter of the body 105, such as wall thickness (T)=OD-ID. According to one embodiment, the axial distance (AD) may be at least 0.1% of a wall thickness (T) of the body 105 [(AD/T)×100%] such as at least 1% or at least 2% or at least 3% or at least 4% or at least 5% or at least 6% or at least 7% or at least 8% or at least 9% or at least 10% or at least 15% or at least 20% or at least 25% or at least 30% or at least 35% or at least 40% or at least 45% or at least 50% or at least 55% or at least 60% or at least 65% or at least 70% or at least 75% or at least 80% or at least 85% or at least 90% or at least 95% or at least 100%. In still another non-limiting embodiment, the axial distance may be not greater than 900% of the wall thickness (T) of the body 105, such as not greater than 500% or not greater than 200% or not greater than 100% or not greater than 90% or not greater than 85% or not greater than 80% or not greater than 75% or not greater than 70% or not greater than 65% or not greater than 60% or not greater than 55% or not greater than 50% or not greater than 45% or not greater than 40% or not greater than 35%. In another embodiment, it will be understood that the axial distance may be within a range between any percentage between at least 0.1% and not greater than 900% of the wall thickness of the body 105.
According to one embodiment, the body 105 may include one or more optional radial members extending radially outward from the outer circumferential surface 205. Referring to the non-limiting embodiment of FIG. 2A, the body 105 includes radial members 221, 222, and 223, (221-223) that extend along the exterior circumferential surface 205 of the body 105. The radial members 221-223 may extend in a non-linear path along the exterior circumferential surface 205, which has both axial and circumferential components defining the pathway. According to one particular embodiment, one or more of the radial members 221-223 may extend in a helical pathway along the circumferential surface 205. In still another non-limiting embodiment, the one or more radial members 221-223 may extend in a helical path with a variable twist, such that the angle of the twist may change along a length of the body 105.
While not illustrated, in another embodiment, one or more optional radial members may extend radially inward from the inner annular surface 209, such that the one or more radial members extend into the central axial opening 207. The one or more radial members may assist with control of the flow of fluids through and around the body 105, which may facilitate reduction in pollutants.
According to one embodiment, the body 105 can have at least one radial member that extends radially outward from the outer circumferential surface 205 that extends for a radial distance (RD) of at least 0.1% of the inner diameter (ID) of the body 105 [(RD/ID)×100%] such as at least 1% or at least 2% or at least 3% or at least 4% or at least 5% or at least 6% or at least 7% or at least 8% or at least 9% or at least 10% or at least 15% or at least 20% or at least 25% or at least 30% or at least 35% or at least 40% or at least 45% or at least 50% or at least 55% or at least 60% or at least 65% or at least 70% or at least 75% or at least 80% or at least 85% or at least 90% or at least 95% or at least 100%. In still another non-limiting embodiment, the radial distance may be not greater than 900% of the inner diameter (ID) of the body 105, such as not greater than 500% or not greater than 200% or not greater than 100% or not greater than 90% or not greater than 85% or not greater than 80% or not greater than 75% or not greater than 70% or not greater than 65% or not greater than 60% or not greater than 55% or not greater than 50% or not greater than 45% or not greater than 40% or not greater than 35%. In another embodiment, it will be understood that the radial distance may be within a range between any percentage between at least 0.1% and not greater than 900% of the inner diameter of the body 105.
In yet another non-limiting embodiment, the body 105 can have at least one radial member that extends radially inward from the inner annular surface 209 that may extend for a radial distance (RD) of at least 0.1% of the inner diameter (ID) of the body 105 [(RD/ID)×100%] such as at least 1% or at least 2% or at least 3% or at least 4% or at least 5% or at least 6% or at least 7% or at least 8% or at least 9% or at least 10% or at least 15% or at least 20% or at least 25% or at least 30% or at least 35% or at least 40% or at least 45% or at least 50% or at least 55% or at least 60% or at least 65% or at least 70% or at least 75% or at least 80% or at least 85% or at least 90% or at least 95% or at least 100%. In still another non-limiting embodiment, the radial distance may be not greater than 900% of the inner diameter (ID) of the body 105, such as not greater than 500% or not greater than 200% or not greater than 100% or not greater than 90% or not greater than 85% or not greater than 80% or not greater than 75% or not greater than 70% or not greater than 65% or not greater than 60% or not greater than 55% or not greater than 50% or not greater than 45% or not greater than 40% or not greater than 35%. In another embodiment, it will be understood that the radial distance may be within a range between any percentage between at least 0.1% and not greater than 900% of the inner diameter of the body 105.
In certain non-limiting instances, the at least one radial member may extend around the outer circumferential surface 205 and/or inner annular surface 209 of the body 105 for a given distance as measured by degrees through which the at least one radial member extends between a proximal end of the radial member and a terminal end of a radial member. For example, one complete turn of the radial member around the entire circumference of the body would be measured as an angle of 360 degrees. According to one embodiment, the at least one radial member extends for a circumferential distance of at least 1 degree on the inner annular surface or outer circumferential surface of the body 105. In other non-limiting instances, the circumferential distance can be greater, such as at least 10 degrees or at least 30 degrees or at least 60 degrees or at least 90 degrees or at least 180 degrees or at least 270 degrees or at least 360 degrees. In one non-limiting instance, the body 105 can have one or more radial members extending for a distance within a range of at least 1 degree and not greater than 3600 degrees.
In one non-limiting embodiment, the one or more radial members may be solid members. That is, the one or more radial members do not necessarily contain internal cavities configured for the flow of fluids (e.g., gasses) therethrough.
Without being bound to a particular theory, it is noted that the position of the body 105 relative to the burner 103 may be suitable to separate the flame from the burner, which may assist in controlling the temperatures in the combustion zone and the formation of pollutants. FIGS. 2D and 2E demonstrate different positions of the body 105 relative to the burner 103, wherein the position of the body 105 in FIG. 2E separates the flame as demonstrated by the colors surrounding the body, whereas in FIG. 2D, the position of the body 105 relative to the burner 103 effectively forces all of the flame from the burner 103 through the body 105.
In another embodiment, controlling the position of the axial distance between the burner 103 and the body 105 may be facilitated by the use of a positioning device. FIG. 3A and FIG. 3B include illustrations of a positioning device 301 according to an embodiment. FIGS. 3C and 3D include illustrations of a positioning device 331. FIGS. 3E and 3F include illustrations of a body 105 including a notch 337 configured to engage the positioning device 331. In one instance, the positioning device may be configured to engage the body 105 and fix the position of the body 105 within the radiant tube 101, and more particularly, fix the position of the body 105 relative to the burner 103.
According to one embodiment, the positioning device 301 can include a positioning element 302 configured to change dimensions of the positioning device 301. In one embodiment, the positioning device 302 can include a first positioning element 303 and a second positioning element 304, wherein the first positioning element 303 comprises a terminal end 311 including an engagement structure 312 configured to engage the body 105, and wherein the second positioning element 304 comprises a terminal end 312 including an engagement structure 313 configured to engage the body 105. The first and second positioning elements 303 and 304 are capable of moving relative to each other, such as sliding relative to each other. In a particular embodiment, the relative movement between the positioning elements 303 and 304 can facilitate containing the body 105 between the engagement structures 312 and 313 at the proximal end 201 and terminal end 203 of the body 105. In one embodiment, the body 105 can be configured to directly or indirectly engage the engagement structures 312 and 313.
As further illustrated in FIGS. 3A and 3B, the positioning device may include a fixing element, configured to be coupled to the radiant tube and fix the positioning device 301 relative to the radiant tube 101. In one embodiment, the first positioning element 303 has a first fixing element 321 that may be in the shape of a semicircle and configured to be coupled to a portion of the radiant tube 101. It will be appreciated that the first fixing element 321 may include other coupling mechanisms for coupling of the positioning device 302 and the body 105, including for example, but not limited to removable coupling elements or permanent coupling elements. A removable coupling element may include an attachment mechanism that is selectively removable from one or both of the positioning device 302 and/or the body 105. A removable coupling element may include a coupling element that can be configured to selectively release the coupling between the body 105 and the positioning device 302 and avoiding damage to the body 105 and positioning device 302 during de-coupling. In one non-limiting embodiment, the removable coupling element may include, but is not limited to a complementary engagement structure, interference fit connection between a portion of the body 105 and the positioning device 302, a fastener or the like. It will be appreciated that in any embodiment, more than one or a combination of different coupling elements may be utilized. In yet another embodiment, a permanent coupling element may include an attachment technique that is not intended to result in de-coupling between the positioning device 302 and the body 105. One example of a permanent coupling element may include a cement, weld, or the like between the body 105 and the positioning device 302.
In another embodiment, the second positioning element 304 may include a second fixing element 322 that may be in the shape of semicircle and configured to be coupled to a portion of the radiant tube 101, such as a flange 341 of the radiant tube 101. It will be appreciated that other shapes of the first and second fixing elements 321 and 322 may be used. In one non-limiting embodiment, the first and second fixing elements 321 and 322 may include one or more openings 351 and 352, respectively. The one or more openings 351 and 352 may facilitate coupling of the first and second fixing elements 321 and 322 to the flange 341 via one or more fasteners.
According to another embodiment, the positioning device 331 may include a terminal end 333 and a proximal end 332 wherein the proximal end 332 terminates closest to the burner 103. In a particular embodiment, the terminal end 333 terminates within the radiant tube 101. In still another embodiment, the terminal end 333 terminates outside of the radiant tube 101 such that it can be accessed easily by an outside user. In still another embodiment, the terminal end 333 terminates outside of the radiant tube 101 such that it can be accessed easily by an outside user at a safe distance from a combustion source (i.e. the burner 103). In one non-limiting embodiment, the positioning device 331 may include a first cross bar 334, a second cross bar 335 and a third cross bar 336 between the terminal end 333 and proximal end 332. In still other embodiments, the positioning device may include multiple cross bars extending between the terminal end 333 and proximal end 332, such as at least two cross bars such as at least three cross bars, or at least four cross bars, or at least five cross bars or even at least six cross bars. In a particular embodiment, the cross bars (334, 335, 336) are configured to engage a notch 337 in the radial member 222 of the body 105. In a non-limiting embodiment, the notch 337 of the body 105 is configured to engage the first cross bar 334. It will be appreciated that in any embodiment, the body 105 may have multiple notches throughout the body 105 to engage multiple cross bars of the positioning device 331 such as at least two notches, or at least three notches, or at least four notches, at least five notches, or even at least six notches. While not illustrated, positioning device 331 may include a locking mechanism configured to lock the position of cross bars (334, 335, 336) to the body 105. The locking mechanism is configured to avoid the decoupling of the positioning device 331 to the notches of the body 105.
According to another embodiment, the positioning device 301, 331 is configured to adjust an axial distance between the body and a combustion source (i.e. the burner). In a particular embodiment, the positioning device 301, 331 is configured to adjust the body between a first position and a second position along an axial length of the radiant tube 101. In one non-limiting embodiment, the first position is at least 0.01 cm from the combustion source or at least 0.1 cm or at least 0.2 cm or at least 0.5 cm or at least 1.0 cm or at least 2 cm or at least 3 cm or at least 4 cm or at least 5 cm or at least 6 cm or at least 7 cm or at least 8 cm or at least 9 cm or at least 10 cm. In still another embodiment, the first position is not greater than 100 cm from the combustion source or not greater than 90 cm or not greater than 80 cm or not greater than 70 cm or not greater than 60 cm or not greater than 50 cm or not greater than 40 cm or not greater than 30 cm. It will be appreciated that the distance can be within a range including any of the minimum and maximum values noted above. In still another embodiment, the second position is at least 0.02 cm from the combustion source or at least 0.1 cm or at least 0.2 cm or at least 0.5 cm or at least 1.0 cm or at least 2 cm or at least 3 cm or at least 4 cm or at least 5 cm or at least 6 cm or at least 7 cm or at least 8 cm or at least 9 cm or at least 10 cm. In still another embodiment, the second position is not greater than 100 cm from the combustion source or not greater than 90 cm or not greater than 80 cm or not greater than 70 cm or not greater than 60 cm or not greater than 50 cm or not greater than 40 cm or not greater than 30 cm. It will be appreciated that the distance can be within a range including any of the minimum and maximum values noted above.
In still another embodiment, the first position and the second position are spaced at least 0.01 cm away from one another or at least 0.02 cm or at least 0.05 cm or at least 1 cm or at least 2 cm or at least 3 cm or at least 4 cm or at least 5 cm or at least 6 cm or at least 7 cm or at least 8 cm or at least 9 cm or at least 10 cm or at least 11 cm or at least 12 cm or at least 13 cm or at least 14 cm or at least 15 cm or at least 16 cm or at least 17 cm or at least 18 cm or at least 19 cm or at least 20 cm. In still another embodiment, the first position and the second position are spaced not greater than 100 cm away from one another or not greater than 90 cm or not greater than 80 cm or not greater than 70 cm or not greater than 60 cm or not greater than 50 cm or not greater than 40 cm or not greater than 30 cm. It will be appreciated that the distance can be within a range including any of the minimum and maximum values noted above. In one non-limiting embodiment, at least one portion of the positioning device, 301, 331 can be configured to be adapted between a first position and a second position without changing a state of the combustion source wherein a state of the combustion source can include the temperature of a heat source. In a particular embodiment, the heat source comprises a flame.
While not illustrated, at least one portion of the positioning device 301, 331 is configured to be accessible by a user at a safe distance from the combustion source (i.e. the burner). A safe distance can be defined as a distance far enough away as to not affect the well-being of the user due to excessive high heat from the combustion source. In still another embodiment, at least one portion of the positioning device 301, 331 is configured to be accessible by a user from a position behind the combustion source. In yet another embodiment, at least one portion of the positioning device 301, 331 is configured to be accessible by a user from an exterior wall behind the combustion source.
According to one embodiment, the positioning device 301, 331 may include a metal, metal alloy, a ceramic, or any combination thereof. In one particular embodiment, the positioning device 301, 331 can include or be made of any of the same materials as used in the body 105. In certain embodiments, it will be appreciated that the positioning device 301, 331 is a separate object from the body 105. Moreover, while some systems may use solid material surrounding the body 105 to control the position of the body 105 in the radiant tube 101, the positioning device is a separate object and does not necessarily surround the body 105 in the radiant tube 101, thus allowing some flow of fluids around the exterior of the body 105, which may facilitate improved operation and performance of the body 105 and/or system 100.
A non-limiting embodiment of a method for reducing pollutants of a combustion assembly is disclosed herein. In a particular embodiment, the method includes measuring pollutants from a combustion reaction within a combustion assembly including at least one combustion source 103 contained within a radiant tube 101 and changing a position of a body 105 within the radiant tube 101 relative to the combustion source 103 while the combustion source 103 is combusting. In still another embodiment, the body 105 comprises a length (L), an outer diameter (OD), and an inner diameter (ID), a proximal surface 201, a terminal surface 203, and a circumferential surface 205 extending between the proximal surface 201 and terminal surface 203. In still another embodiment, changing a position of the body 105 includes adjusting the position without interrupting the combustion source. In a particular embodiment, the combustion source 103 may include a burner. In still another embodiment, the burner remains in a fully-assembled state. In yet another embodiment, the combustion source 103 may include a terminal end 211 configured for the combustion of gases and formation of a flame in the radiant tube.
In another embodiment, the body 105 is configured to be disposed at an axial distance from the terminal end 211 of the combustion source 103. For example, in one non-limiting embodiment, the axial distance (AD) may be at least a 0.1% of the length (L) of the body 105 [(AD/L)×100%], such as at least 1% or at least 2% or at least 35% or at least 104% or at least 5% or at least 6% or at least 7% or at least 8% or at least 9% or at least 10% or at least 15% or at least 20% or at least 25% or at least 30% or at least 35% or at least 40% or at least 45% or at least 50% or at least 55% or at least 60% or at least 65% or at least 70% or at least 75% or at least 80% or at least 85% or at least 90% or at least 95% or at least 100%. In still another non-limiting embodiment, the axial distance may be not greater than 900% of the length of the body, such as not greater than 500% or not greater than 200% or not greater than 100% or not greater than 90% or not greater than 85% or not greater than 80% or not greater than 75% or not greater than 70% or not greater than 65% or not greater than 60% or not greater than 55% or not greater than 50% or not greater than 45% or not greater than 40% or not greater than 35%. In another embodiment, it will be understood that the axial distance may be within a range between any percentage between at least 0.1% and not greater than 900% of the length of the body 105.
In still other embodiment, changing a position of the body 105 may include adjusting the body between a first position and a second position along an axial length of the radiant tube 101. In one non-limiting embodiment, the first position is at least 0.01 cm from the combustion source 103 or at least 0.1 cm or at least 0.2 cm or at least 0.5 cm or at least 1.0 cm or at least 2 cm or at least 3 cm or at least 4 cm or at least 5 cm or at least 6 cm or at least 7 cm or at least 8 cm or at least 9 cm or at least 10 cm. In still another embodiment, the second position is at least 0.02 cm from the combustion source 103 or at least 0.1 cm or at least 0.2 cm or at least 0.5 cm or at least 1.0 cm or at least 2 cm or at least 3 cm or at least 4 cm or at least 5 cm or at least 6 cm or at least 7 cm or at least 8 cm or at least 9 cm or at least 10 cm. In still another embodiment, the first position and the second position are spaced at least 0.01 cm away from one another or at least 0.02 cm or at least 0.05 cm or at least 1 cm or at least 2 cm or at least 3 cm or at least 4 cm or at least 5 cm or at least 6 cm or at least 7 cm or at least 8 cm or at least 9 cm or at least 10 cm or at least 11 cm or at least 12 cm or at least 13 cm or at least 14 cm or at least 15 cm or at least 16 cm or at least 17 cm or at least 18 cm or at least 19 cm or at least 20 cm. In still another embodiment, the first position and the second position are spaced not greater than 100 cm away from one another or not greater than 90 cm or not greater than 80 cm or not greater than 70 cm or not greater than 60 cm or not greater than 50 cm or not greater than 40 cm or not greater than 30 cm. It will be appreciated that the distance can be within a range including any of the minimum and maximum values noted above.
In one non-limiting embodiment, changing a position of the body 105 may include using a positioning device 301, 331. The positioning device 301, 331 may include any of the features as disclosed herein. In still another embodiment, the position device 301, 331 is configured to be accessible by a user at a safe distance from the combustion source (i.e. the burner). A safe distance can be defined as a distance far enough away as to not affect the well-being of the user due to excessive high heat from the combustion source. In still another embodiment, at least one portion of the positioning device 301, 331 is configured to be accessible by a user from a position behind the combustion source. In yet another embodiment, at least one portion of the positioning device 301, 331 is configured to be accessible by a user from an exterior wall behind the combustion source.
In still other embodiment, measuring the pollutants may include measuring a content of nitrogen oxides (NOx). It will be appreciated that the content of nitrogen oxides (NOx) can be measured using methods known to those skilled in the art. In another non-limiting embodiment, the method for reducing pollutants of a combustion assembly may further include reducing the nitrogen oxide (NOx) content by at least 10%, such as at least 12% or at least 15% or at least 18% or at least 20% or at least 25% or at least 30%.
FIGS. 4A-4C include illustrations of an exchange body according to an embodiment.
FIG. 4A includes a side view of an exchange body according to an embodiment. FIG. 4B includes a cross-sectional view of the exchange body of FIG. 4A. FIG. 4C includes a cross-sectional view of the exchange body in a plane perpendicular to the view of FIG. 4B for the exchange body of FIG. 4A. According to an embodiment, the exchange body 107 can be contained in the radiant tube 101 and configured to facilitate the exchange of heat between multiple flow paths of fluids flowing through and around exchange body 107.
In one embodiment, the exchange body 107 may include a central cavity 401 extending along a length (L) of the exchange body 107, a plurality of spirals 403 extending around the central cavity 401, and a plurality of interspiral channels 405 disposed between the plurality of spirals 403. As depicted, the plurality of spirals 403 and the plurality of interspiral channels 405 may extend in a non-linear pathway along the length (L) of the exchange body 107. According to one particular embodiment, the plurality of spirals 403 may extend in a helical pathway around the exchange body 107 and the central cavity 401. In still another non-limiting embodiment, the plurality of spirals 403 may extend in a helical path with a variable twist, such that the angle of the twist may change along a length of the exchange body 107.
In another embodiment, the exchange body 107 may also include intraspiral channels 407 extending within the spirals 403. The intraspiral cavities 407 can be completely isolated from the interspiral channels by the side walls 409, which allows the separation of fluids along separate flow paths defined by the interspiral channels 405 and the intraspiral cavities 407.
As depicted, the intraspiral channels 407 may extend in a non-linear pathway along the length (L) of the exchange body 107. According to one particular embodiment, the intraspiral channels 407 may extend in a helical pathway around the exchange body 107 and the central cavity 401. In still another non-limiting embodiment, the intraspiral channels 407 may extend in a helical path with a variable twist, such that the angle of the twist may change along a length of the exchange body 107.
According to one embodiment, the exchange body 107 may have a particular exchange ratio as defined by the surface area (mm²)/volume (mm³) that facilitates improved heat exchange between the fluids flowing through the exchange body 107. For example, in one embodiment, the exchange ratio can be at least 0.09 mm⁻¹, such as at least 0.10 mm^-1or at least 0.11 mm⁻¹or at least 0.12 mm⁻¹or at least 0.13 mm⁻¹. Still, in a non-limiting embodiment, the exchange ratio can be not greater than 0.5 mm⁻¹or not greater than 0.4 mm⁻¹or not greater than 0.3 mm⁻¹. It will be appreciated that the exchange ratio can be within a range including any of the minimum and maximum values noted above.
In another embodiment, the exchange body 107 may have a particular hot/cold flowpath area (HCFA) ratio, which may facilitate improved heat exchange between the fluids flowing through the exchange body 107. For example, in one embodiment, the HCFA ratio can be at least 1, such as at least 1.05 or at least 1.10 or at least 1.15 or at least 1.2 or at least 1.25. Still, in another embodiment, the HCFA ratio can be not greater than 5, such as not greater than 4 or not greater than 3 or not greater than 2.8 or not greater than 2.5. It will be appreciated that the HCFA ratio can be within a range including any of the minimum and maximum values noted above.
The HCFA ratio is measured by evaluating the cross-sectional area of the hot and cold pathways in the exchange body as viewed in cross-section. For example, as shown in FIG. 4C, the exchange body 107 can have hot flow paths as defined by the central cavity 401 and the interspiral channels 405. The cold flow paths can be defined by the intraspiral cavities 407. The cross-sectional area of all of the channels and/or cavities as viewed in cross-section at the midpoint of the exchange body 107 (i.e., the bisecting axis along the length) is used for the calculation of the ratio. More particularly, the cross-sectional area of all of the channels and/or cavities for the flow of hot fluids (as viewed in cross-section) is divided by the surface area of the channels and/or cavities for the flow of cold fluids to calculate the HCFA ratio. The HCFA ratio of the embodiments herein can facilitate improved heat exchange between the hot and cold fluid pathways by controlling the pressure drop with the exchange body 107.
In another non-limiting embodiment, the central cavity 401 of the exchange body 107 can include at least one groove 43 lextending in a non-linear pathway along the inner annular surface 432, such as a helical pathway along the inner annular surface 432 that defines the central cavity 401. In one non-limiting embodiment, the at least one groove 431 may extend circumferentially for a distance of at least 1 degree as measured by an angle extending through a circumferential distance of the exchange body 107. In other non-limiting instances, the circumferential distance can be greater, such as at least 10 degrees or at least 30 degrees or at least 60 degrees or at least 90 degrees or at least 180 degrees or at least 270 degrees or at least 360 degrees. In one non-limiting instance, the circumferential distance can be within a range of at least 1 degree and not greater than 3600 degrees (i.e., 10 full turns around the circumference of the exchange body 107). For example, one complete turn of the at least one groove 431 through the entire circumference of the exchange body 107 would be measured as an angle of 360 degrees.
According to one embodiment, the at least one groove 431 can extend into the body for a radial depth 435 of at least 0.1% and not greater than 49% of an inner diameter (ID) of the exchange body 107. In another embodiment, the radial depth 435 can be within a range including any percentages between at least 0.1% and not greater than 49% of the ID.
According to one embodiment, the at least one groove 431 can extend into the body for a radial depth 435 of at least 0.1% and not greater than 100% of a length of the exchange body 107. In another embodiment, the radial depth 435 can be within a range including any percentages between at least 0.1% and not greater than 100% of the length of the exchange body 107.
FIG. 4D includes a cross-sectional illustration of the exchange body 107 in a radiant tube 101. As illustrated, a radial gap 441 may exist between the inner surface of the radiant tube 101 and the outer circumferential surface of the exchange body 107, which is defined by the outer surfaces of the spirals 403. In one embodiment, the radial gap 441 can define a gap distance 442, which is measured radially between the objects, may be within a range of at least 0.1% and not greater than 1000% of an interspiral channel width 443. The interspiral channel width 443 is measured as the largest gap between immediately adjacent spirals as viewed in cross-section. In still another embodiment, the gap distance 442 may be within a range of at least 0.1% and not greater than 400% of the interspiral channel width 443.
In one non-limiting embodiment, it may be suitable that the radial gap 441 defining the gap distance 442 is free of any solid materials, which may allow greater fluid flow and may facilitate improved exchange of heat between flow paths. In one particular embodiment, the radial gap 441 may be free of solid material. In another embodiment, the radial gap 441 may be unobstructed and define an opening or open space between the radiant tube 101 and the exchange body 107.
According to one embodiment, the exchange body may be made of a ceramic material, such as an oxide, carbide, nitride, boride, or any combinations thereof. In one particular embodiment, the exchange body 107 may include silicon carbide and may consist essentially of silicon carbide. The exchange body 107 can be made using any of the same techniques described herein to make the body 105.
The exchange body 107 can have a flange 451, which is fastened or coupled to the radiant tube 101 to fix the relative positions between the radiant tube 101 and the exchange body 107. In some instances, one or more gaskets can be coupled to the surfaces of the flange 451. The gaskets can be compressible members, which seal the system and avoid leakage of fluids. In one embodiment, the gasket can have a maximum compression (i.e., reduction in thickness as compared to original thickness) by at least 10% of its original thickness, such as at least 20% or at least 30% or at least 40% or at least 50% or at least 60% of the original thickness.
In the foregoing specification, the concepts have been described with reference to specific embodiments. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the invention.

Claims

What is claimed is:

1. A body configured to be installed into a radiant tube for reduction of pollutants, the body comprising:

a body having a tube shape including a length, an outer diameter, and an inner diameter, wherein the body further comprises a proximal surface, a terminal surface, and a circumferential surface extending between the proximal surface and terminal surface; and

wherein the body is configured to be disposed at an axial distance from a terminal end of a burner, wherein the axial distance (AD) is at least a 0.1% of the length of the body.

2. The body of claim 1, wherein the axial distance is within a range of at least 0.1% and not greater than 1000% of the length of the body or any percentage therebetween.

3. The body of claim 1, wherein the axial distance is within a range of at least 0.1% and not greater than 100% of a wall thickness of the body or any percentage therebetween, wherein the wall thickness is the difference in the outer diameter of the body relative to the inner diameter.

4. The body of claim 1, wherein the body consists of a single monolithic body having a single axial opening extending the length of the body and a solid side wall surrounding the axial opening for the length of the body.

5. A system configured to be installed into a radiant tube for reduction of pollutants, the system comprising:

a body having a tube shape including a length, a width, an outer diameter, and an inner diameter, wherein the body further comprises a proximal surface, a terminal surface, and a circumferential surface extending between the proximal surface and terminal surface; and

a positioning device configured to engage the body, wherein the positioning device is configured to adjust an axial distance between the body and a combustion source.

6. The system of claim 5, wherein the positioning device comprises a first positioning element and a second positioning element, wherein the first positioning element comprises a terminal end including an engagement structure configured to engage the body, and wherein the second positioning element comprises a terminal end including an engagement structure configured to engage the body.

7. The system of claim 5, wherein the positioning device comprises a proximal end and a terminal end and a first cross bar between the proximal end and the terminal end configured to engage the body.

8. The system of claim 7, wherein the body comprises a notch configured to engage the first cross bar of the positioning device.

9. The system of claim 7, wherein the terminal end of the positioning device terminates outside of the radiant tube.

10. The system of claim 9 wherein the terminal end of the positioning device is accessible to an outside user.

11. The system of claim 5, wherein the positioning device is configured to adjust the body between a first position and a second position along an axial length of the radiant tube.

12. The system of claim 11, wherein the first position is at least 0.01 cm and not greater than 100 cm from the combustion source.

13. The system of claim 11, wherein the second position is at least 0.02 cm and not greater than 100 cm from the combustion source.

14. The system of claim 11, wherein the first position and the second position are spaced at least 0.01 cm and not greater than 100 cm away from one another.

15. The system of claim 5, wherein at least one portion of the positioning device is configured to be accessible by a user at a safe distance from the combustion source.

16. The system of claim 11, wherein at least one portion of the positioning device is configured to be adapted between a first position and a second position without changing a state of the combustion source.

17. A method for reducing pollutants of a combustion assembly comprising:

measuring pollutants from a combustion reaction within a combustion assembly including at least one combustion source contained within a radiant tube; and

changing a position of a body within the radiant tube relative to the combustion source while the combustion source is combusting; wherein the body comprises a length, an outer diameter, and an inner diameter, wherein the body further comprises a proximal surface, a terminal surface, and a circumferential surface extending between the proximal surface and terminal surface.

18. The method of claim 17, wherein changing a position of the body comprises adjusting the position without interrupting the combustion source.

19. The method of claim 17, wherein changing a position of the body comprises adjusting the body between a first position and a second position along an axial length of the radiant tube.

20. The method of claim 17, wherein changing a position of the body comprises using a positioning device.