U.S. patent application number 16/560121 was filed with the patent office on 2019-12-26 for post-manufacturing processes for submerged combustion burner.
The applicant listed for this patent is JOHNS MANVILLE. Invention is credited to John Wayne Baker, Juan Carlos Madeni.
Application Number | 20190389757 16/560121 |
Document ID | / |
Family ID | 57994467 |
Filed Date | 2019-12-26 |
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United States Patent
Application |
20190389757 |
Kind Code |
A1 |
Madeni; Juan Carlos ; et
al. |
December 26, 2019 |
POST-MANUFACTURING PROCESSES FOR SUBMERGED COMBUSTION BURNER
Abstract
A portion of a submerged combustion burner is disposed into a
pressure vessel. The portion of the submerged combustion burner has
a welded area that has a first microstructure defined by a first
number of voids. The vessel is filled with an inert gas,
pressurized, and heated. Pressurizing and heating operations are
performed for a time and at a temperature and a pressure sufficient
to produce a second microstructure in the welded area of the
burner. The second microstructure is defined by a second number of
voids less than the first number of voids.
Inventors: |
Madeni; Juan Carlos;
(Littleton, CO) ; Baker; John Wayne; (Golden,
CO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
JOHNS MANVILLE |
Denver |
CO |
US |
|
|
Family ID: |
57994467 |
Appl. No.: |
16/560121 |
Filed: |
September 4, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15666762 |
Aug 2, 2017 |
10442717 |
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16560121 |
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14824981 |
Aug 12, 2015 |
9751792 |
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15666762 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F23D 2213/00 20130101;
C03B 2211/22 20130101; C21D 9/50 20130101; F23D 14/76 20130101;
Y02P 40/50 20151101; C21D 9/0068 20130101; C03B 2211/60 20130101;
Y02P 40/57 20151101; C03B 5/2356 20130101; C21D 1/74 20130101; C03B
5/44 20130101; Y02P 40/55 20151101 |
International
Class: |
C03B 5/235 20060101
C03B005/235; C21D 9/00 20060101 C21D009/00; C21D 9/50 20060101
C21D009/50; C21D 1/74 20060101 C21D001/74; F23D 14/76 20060101
F23D014/76 |
Claims
1. A system comprising: a melt vessel configured to receive a
material and melt the material into a matrix, the melt vessel
including: a base; a feed end wall defining a feed port for
receiving the material; an exit end wall defining an exit port
allowing egress of the matrix; and a roof, wherein the base, the
feed end wall, the exit end wall, and the roof form a substantially
closed volume; a transition channel in fluid communication with the
exit port for receiving the matrix from the exit port; a plurality
of burners disposed so as to penetrate the base, wherein at least
one of the plurality of burners comprises: a toroidal burner tip
defining an outlet for delivering the combustion gases into the
substantially closed volume; a portion exposed to the matrix,
wherein the portion of the burner exposed to the matrix includes a
plurality of polished features having heights not greater than 1
micron.
2. The system of claim 1, wherein the portion exposed to the matrix
comprises the toroidal tip.
3. The system of claim 1, wherein the portion exposed to the matrix
comprises a burner body.
4. The system of claim 1, wherein the plurality of polished
features have heights of less than about 0.5 micron.
5. A system comprising: a melt vessel configured to receive a
material and melt the material into a matrix, the melt vessel
including: a base; a feed end wall defining a feed port for
receiving the material; an exit end wall defining an exit port
allowing egress of the matrix; and a roof, wherein the base, the
feed end wall, the exit end wall, and the roof form a substantially
closed volume; a transition channel in fluid communication with the
exit port for receiving the matrix from the exit port; a plurality
of burners disposed so as to penetrate the base, wherein at least
one of the plurality of burners comprises a welded portion having a
void fraction of less than about 1%.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of pending U.S. application
Ser. No. 15/666,762, filed Aug. 2, 2017 which application is a
divisional of U.S. application Ser. No. 14/824,981, filed Aug. 12,
2015, now U.S. Pat. No. 9,751,792 issued Sep. 5, 2017.
BACKGROUND
[0002] In submerged combustion melting (SCM), combustion gases are
injected beneath a surface of a molten matrix and rise upward
through the melt. The matrix may include glass and/or inorganic
non-metallic feedstocks such as rock (basalt) and mineral wool
(stone wool). Regardless of the material utilized, it is heated at
a high efficiency via the intimate contact with the combustion
gases and melts into a matrix. Using submerged combustion burners
produces violent turbulence of the molten matrix and results in a
high degree of mechanical energy in the submerged combustion
melter. In this violent environment, the burners are subjected to
significant thermal and mechanical stresses that may result in
increased likelihood of early failure.
SUMMARY
[0003] In one aspect, the technology relates to a method including
disposing at least a portion of a submerged combustion burner into
a pressure vessel, wherein the portion of the submerged combustion
burner has a first microstructure defined by a first number of
voids; filling the vessel containing the portion of the submerged
combustion burner with an inert gas; pressurizing the vessel
containing the portion of the submerged combustion burner; and
heating the vessel containing the portion of the submerged
combustion burner, wherein the pressurizing and heating operations
are performed for a time and at a temperature and a pressure
sufficient to produce a second microstructure in the burner,
wherein the second microstructure is defined by a second number of
voids less than the first number of voids. In an embodiment, the
portion includes at least one of a burner body, a burner tip, and a
burner base. In another embodiment, the temperature is in a range
from about 2200 degrees F. to about 3000 degrees F. In yet another
embodiment, the temperature is in a range from about 2450 degrees
F. to about 2750 degrees F. In still another embodiment, the
temperature is about 2600 degrees F.
[0004] In another embodiment of the above aspect, the time is in a
range from about 100 minutes to about 1000 minutes. In an
embodiment, the time is in a range from about 200 minutes to about
600 minutes. In another embodiment, the time is about 365 minutes.
In yet another embodiment, the pressure is in a range of between
about 20,000 psi and about 50,000 psi. In still another embodiment,
the pressure is in a range of between about 25,000 psi and about
40,000 psi.
[0005] In yet another embodiment of the above aspect, the pressure
is about 30,000 psi. In an embodiment, the method further includes
weld-repairing a defect in the portion of the submerged burner
before disposing the portion of the submerged burner in the
pressure vessel. In another embodiment, the method further
includes: removing the portion of the submerged burner from the
pressure vessel; non-destructively testing the portion of the
submerged burner for a defect; weld-repairing the defect; and
returning the portion of the submerged combustion burner to the
pressure vessel.
[0006] In another aspect, the technology relates to a method
including: disposing a toroidal tip of a submerged combustion
burner in a vise, wherein the toroidal tip has an average first
surface roughness across an area of the toroidal tip; and polishing
the toroidal tip of the submerged combustion burner to an average
second surface roughness across the area of the toroidal tip,
wherein the average second surface roughness is less than the
average first surface roughness. In an embodiment, the area of the
toroidal tip includes a plurality of initial surface features
having heights of about 10 microns to about 100 microns prior to
polishing. In another embodiment, the area of the toroidal tip
includes a plurality of polished features having heights not
greater than 1 micron after polishing. In yet another embodiment,
the area of the toroidal tip includes a plurality of polished
features having heights between about 1 micron and about 0.1 micron
after polishing. In still another embodiment the average second
surface roughness is about 5% of the first surface roughness.
[0007] In another embodiment of the above aspect, the average
second surface roughness is about 1% of the first surface
roughness. In an embodiment, the average second surface roughness
is about 0.1% of the first surface roughness. In another
embodiment, the polishing operation is performed substantially
circumferentially. In yet another embodiment, the polishing
operation is performed randomly.
[0008] In another aspect, the technology relates to a system
having: a melt vessel configured to receive a material and melt the
material into a matrix, the melt vessel including: a base; a feed
end wall defining a feed port for receiving the material; an exit
end wall defining an exit port allowing egress of the matrix; and a
roof, wherein the base, the feed end wall, the exit end wall, and
the roof form a substantially closed volume; a transition channel
in fluid communication with the exit port for receiving the matrix
from the exit port; a plurality of burners disposed so as to
penetrate the base, wherein at least one of the plurality of
burners includes: a toroidal burner tip defining an outlet for
delivering the combustion gases into the substantially closed
volume; a portion exposed to the matrix, wherein the portion of the
burner exposed to the matrix includes a plurality of polished
features having heights not greater than 1 micron. In an
embodiment, the portion exposed to the matrix includes the toroidal
tip. In another embodiment, the portion exposed to the matrix
includes a burner body. In yet another embodiment, the plurality of
polished features has heights of less than about 0.5 micron.
[0009] In another aspect, the technology relates to a system
having: a melt vessel configured to receive a material and melt the
material into a matrix, the melt vessel including: a base; a feed
end wall defining a feed port for receiving the material; an exit
end wall defining an exit port allowing egress of the matrix; and a
roof, wherein the base, the feed end wall, the exit end wall, and
the roof form a substantially closed volume; a transition channel
in fluid communication with the exit port for receiving the matrix
from the exit port; a plurality of burners disposed so as to
penetrate the base, wherein at least one of the plurality of
burners includes a microstructure having a void fraction of less
than about 1%.
[0010] This summary is provided to introduce a selection of
concepts in a simplified form that are further described below in
the Detailed Description. This summary is not intended to identify
key features or essential features of the claimed subject matter,
nor is it intended to be used to limit the scope of the claimed
subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The same number represents the same element or same type of
element in all drawings.
[0012] FIG. 1 is a longitudinal cross-section view of a burner.
[0013] FIGS. 2-11 are schematic longitudinal cross-sectional views
various examples of submerged combustion burners.
[0014] FIGS. 2A, 6A, 7A, 8A, and 11A are detailed cross-sectional
views of various burner features described herein.
[0015] FIGS. 12A and 12B are a view and an enlarged view of a
burner surface.
[0016] FIG. 13 depicts a method of polishing a portion of a burner
after manufacture.
[0017] FIGS. 14A and 14B depict microstructures of a cast precious
metal samples before and after hot isostatic pressing processes,
respectively.
[0018] FIG. 15 depicts a method of hot isostatic processing a
portion of a burner after manufacture.
[0019] FIG. 16 depicts a schematic sectional view of a submerged
combustion melter system.
DETAILED DESCRIPTION
[0020] In the following description, numerous details are set forth
to provide an understanding of various melter apparatus and process
examples in accordance with the present disclosure. However, it
will be understood by those skilled in the art that the melter
apparatus and processes of using same may be practiced without
these details and that numerous variations or modifications from
the described examples may be possible which are nevertheless
considered within the appended claims. All published patent
applications and patents referenced herein are hereby incorporated
by reference herein in their entireties.
[0021] The technologies described herein relate generally to
burners used in a submerged combustion melter (SCM). In general,
all burners require use of robust structure and materials so as to
withstand mechanical and thermal stresses and fatigue while in the
SCM environment. As such, material selection, manufacturing
details, and post-manufacturing processing are all critical to help
ensure a long service life of an SCM burner. The burners described
herein, along with desirable materials, post-manufacturing
processes, and so on, are uniquely suited to the SCM environment.
SCM burners need not display all material, processing or functional
properties described herein; however, it has been discovered that
SCM burners having one or more of these characteristics can display
significant advantages over burners not so constructed. Burners
displaying many such characteristics display even greater
advantages. Given the nature of the SCM process, very robust
burners are desirable to avoid melter system downtime. FIG. 1
depicts a side sectional view of a burner 1 that may be utilized in
conjunction with the examples of the technology described herein.
The burner 1 is a submerged combustion melting (SCM) burner having
a fluid-cooled portion 2 having a burner tip 4 attached to a burner
body 6. A burner main flange 8 connects the burner to an SCM
superstructure or melter system, illustrated below. Burner body 6
has an external conduit 10, a first internal conduit 12, a second
internal conduit 14, and end plates 16, 18. A coolant fluid inlet
conduit 20 is provided, along with a coolant fluid exit conduit 22,
allowing ingress of a cool coolant fluid as indicated by an arrow
CFI, and warmed coolant fluid egress, as indicated by an arrow CFO,
respectively. A first annulus 11 is thus formed between
substantially concentric external conduit 10 and first internal
conduit 12, and a second annulus 13 is formed between substantially
concentric first and second internal conduits 12, 14. A proximal
end 24 of second internal conduit 14 may be sized to allow
insertion of a fuel or oxidant conduit 15 (depending on the burner
arrangement), which may or may not include a distal end nozzle 17.
When conduit 15 and optional nozzle 17 are inserted internal of
second internal conduit 14, a third annulus is formed there
between. In certain examples, oxidant flows through the third
annulus, while one or more fuels flow through conduit 15, entering
through a port 44. In certain other examples, one or more fuels
flow through the third annulus, while oxidant flows through conduit
15, entering through port 44.
[0022] Burners described herein may be air-fuel burners that
combust one or more fuels with only air, or oxy-fuel burners that
combust one or more fuels with either oxygen alone, or employ
oxygen-enriched air, or some other combination of air and oxygen,
including combustion burners where the primary oxidant is air, and
secondary and tertiary oxidants are oxygen. Burners may be
comprised of metal, ceramic, ceramic-lined metal, or combination
thereof. Air in an air-fuel mixture may include ambient air as well
as gases having the same molar concentration of oxygen as air.
Oxygen-enriched air having an oxygen concentration greater than 121
mole percent may be used. Oxygen may include pure oxygen, such as
industrial grade oxygen, food grade oxygen, and cryogenic oxygen.
Oxygen-enriched air may have 50 mole percent or more oxygen, and in
certain examples may be 90 mole percent or more oxygen. Oxidants
such as air, oxygen-enriched air, and pure oxygen may be supplied
from a pipeline, cylinders, storage facility, cryogenic air
separation unit, membrane permeation separator, or adsorption
unit.
[0023] The fuel burned by the burners may be a combustible
composition (either in gaseous, liquid, or solid form, or any
flowable combination of these) having a major portion of, for
example, methane, natural gas, liquefied natural gas, propane,
atomized oil, powders or the like. Contemplated fuels may include
minor amounts of non-fuels therein, including oxidants, for
purposes such as premixing the fuel with the oxidant, or atomizing
liquid fuels.
[0024] The fluid-cooled portion 2 of the burner 1 includes a
ceramic or other material insert 26 fitted to the distal end of
first internal conduit 12. Insert 26 has a shape similar to but
smaller than burner tip 4, allowing coolant fluid to pass between
burner tip 4 and insert 26, thus cooling burner tip 4. Various
types of coolants are described below. Burner tip 4 includes an
inner wall 28, an outer wall 30, and a crown 32 connecting inner
wall 28 and outer wall 30. In examples, welds at locations 34 and
36, and optionally at 38, 40 and 42, connect burner tip 4 to
external conduit 10 and second internal conduit 14, using
conventional weld materials to weld together similar base metal
parts, such as carbon steel, stainless steel, or titanium.
[0025] Selection of burner tip material and type of connections
between the burner tip walls and conduits forming the burner body
may significantly increase the operating life of submerged
combustion burners used to melt materials in an SCM. More
particularly, at least one of the corrosion and/or fatigue
resistance of the outer wall of the burner tip is greater than
material comprising the external conduit under conditions
experienced during submerged combustion melting of materials.
Additionally, the surfaces of the burner (including the burner tip
or burner body) may be further processed after manufacture so as to
increase performance and reduce materials imperfections so as to
improve resistance of these components to fatigue.
[0026] Burner tips may be manufactured of noble metals or other
exotic corrosion and/or fatigue-resistant materials, such as
platinum (Pt), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver
(Ag), osmium (Os), iridium (Ir), and gold (Au); alloys of two or
more noble metals; and alloys of one or more noble metals with a
base metal. In certain examples the burner tip may be a
platinum/rhodium alloy attached to the base metals comprising the
burner body using a variety of techniques, such as brazing, flanged
fittings, interference fittings, friction welding, threaded
fittings, and the like, as further described herein with regard to
specific examples. Threaded connections may eliminate the need for
third party forgings and expensive welding or brazing
processes--considerably improving system delivery time and overall
cost. It will be understood, however, that the use of third party
forgings, welding, and brazing are not ruled out for burners
described herein, and may actually be preferable in certain
situations. Such connections are described in the examples
below.
[0027] When in alloyed form, alloys of two or more noble metals may
have any range of noble metals. For example, alloys of two noble
metals may have a range of about 0.01 to about 99.99 percent of a
first noble metal and 99.99 to 0.01 percent of a second noble
metal. Any and all ranges in between 0 and 99.99 percent first
noble metal and 99.99 and 0 percent second noble metal are
considered within the present disclosure, including 0 to about 99
percent of first noble metal; 0 to about 98 percent; 0 to about 97
percent; 0 to about 96; 0 to about 95; 0 to about 90; 0 to about
80; 0 to about 75; 0 to about 70; 0 to about 65; 0 to about 60; 0
to about 55; 0 to about 50; 0 to about 45, 0 to about 40; 0 to
about 35; 0 to about 30; 0 to about 25; 0 to about 20; 0 to about
19; 0 to about 18; 0 to about 17; 0 to about 16; 0 to about 15; 0
to about 14; 0 to about 13; 0 to about 12; 0 to about 11; 0 to
about 10; 0 to about 9; 0 to about 8; 0 to about 7; 0 to about 6; 0
to about 5; 0 to about 4; 0 to about 3; 0 to about 2; 0 to about 1;
and 0 to about 0.5 percent of a first noble metal; with the balance
comprising a second noble metal, or consisting essentially of a
second noble metal (for example with one or more base metals
present at no more than about 10 percent, or no more than about 9
percent base metal, or no more than about 8, or about 7, or about
6, or about 5, or about 4, or about 3, or about 2, or no more than
about 1 percent base metal).
[0028] Certain noble metal alloy examples include three or more
noble metals, the percentages of each individual noble metal may
range from equal amounts of all noble metals in the composition
(about 33.33 percent of each), to compositions comprising, or
consisting essentially of, 0.01 percent of a first noble metal,
0.01 percent of a second noble metal, and 99.98 percent of a third
noble metal. Any and all ranges in between about 33.33 percent of
each, and 0.01 percent of a first noble metal, 0.01 percent of a
second noble metal, and 99.98 percent of a third noble metal, are
considered within the present disclosure.
[0029] The choice of a particular material is dictated among other
parameters by the chemistry, pressure, and temperature of fuel and
oxidant used and type of glass matrix to be produced. The skilled
artisan, having knowledge of the particular application, pressures,
temperatures, and available materials, will be able design the most
cost effective, safe, and operable burners for each particular
application without undue experimentation.
[0030] Various metals and metal alloys may display both corrosion
resistance and fatigue resistant resistance. These two terms are
used herein refer to two different failure mechanisms (corrosion
and fatigue) that may occur simultaneously, and it is theorized
that these failure mechanisms may actually influence each other in
profound ways. As such, the present application utilizes a term
that may be used to describe these dual influences, denoted
"cortigue" or "cortigue resistance." These terms refer to a burner
tip material that will have a satisfactory service life of at least
12 months under conditions existing in a continuously operating SCM
adjacent to the burner tip. As used herein the SCM may comprise a
floor, a roof, and a sidewall structure connecting the floor and
roof defining an internal space, at least a portion of the internal
space comprising a melting zone, and one or more combustion burners
in either the floor, the roof, the sidewall structure, or any two
or more of these, producing combustion gases and configured to emit
the combustion gases from a position under a level of, and
positioned to transfer heat to and produce, a turbulent molten mass
of glass containing bubbles in the melting zone. An example of an
SCM system is depicted below in FIG. 16.
[0031] Certain examples may comprise a burner tip insert shaped
substantially the same as but smaller than the burner tip and
positioned in an internal space defined by the burner tip, the
insert configured so that a cooling fluid may pass between internal
surfaces of the burner tip and an external surface of the insert.
In these examples a first or distal end of the first internal
conduit would be attached to the insert. In certain examples, the
inner and outer walls of the burner tip body may extend beyond the
first end of the first internal conduit, at least partially
defining a mixing region for oxidant and fuel.
[0032] Conduits of burner bodies and associated components (such as
spacers and supports between conduits, but not burner tips) used in
SC burners, SCMs and processes of the present disclosure may be
comprised of metal, ceramic, ceramic-lined metal, or combination
thereof. Suitable metals include carbon steels, stainless steels,
for example, but not limited to, 306 and 316 steel, as well as
titanium alloys, aluminum alloys, and the like. High-strength
materials like C-110 and C-125 metallurgies that are qualified
under standards set by NACE International of Houston, Tex., may be
employed for burner body components. Use of high strength steel and
other high strength materials may significantly reduce the conduit
wall thickness required, reducing weight of the burners.
[0033] The melter geometry and operating temperature, burner and
burner tip geometry, and type of glass to be produced, may dictate
the choice of a particular material, among other parameters.
[0034] In certain SCMs, one or more burners in the SCM and/or flow
channel(s) downstream thereof may be adjustable with respect to
direction of flow of the combustion products. Adjustment may be via
automatic, semi-automatic, or manual control. Certain system
examples may comprise a burner mount that mounts the burner in the
wall structure, roof, or floor of the SCM and/or flow channel
comprising a refractory, or refractory-lined ball joint. Other
burner mounts may comprise rails mounted in slots in the wall or
roof. In yet other examples the burners may be mounted outside of
the melter or channel, on supports that allow adjustment of the
combustion products flow direction. Useable supports include those
comprising ball joints, cradles, rails, and the like.
[0035] Certain SCMs and process examples of this disclosure may be
controlled by one or more controllers. For example, burner
combustion (flame) temperature may be controlled by monitoring one
or more parameters selected from velocity of the fuel, velocity of
the primary oxidant, mass and/or volume flow rate of the fuel, mass
and/or volume flow rate of the primary oxidant, energy content of
the fuel, temperature of the fuel as it enters the burner,
temperature of the primary oxidant as it enters the burner,
temperature of the effluent, pressure of the primary oxidant
entering the burner, humidity of the oxidant, burner geometry,
combustion ratio, and combinations thereof. Certain SCMs and
processes of this disclosure may also measure and/or monitor feed
rate of batch or other feed materials, such as glass batch, cullet,
mat or wound roving and treatment compositions, mass of feed, and
use these measurements for control purposes. Exemplary systems and
methods of the disclosure may comprise a combustion controller
which receives one or more input parameters selected from velocity
of the fuel, velocity of oxidant, mass and/or volume flow rate of
the fuel, mass and/or volume flow rate of oxidant, energy content
of the fuel, temperature of the fuel as it enters the burner,
temperature of the oxidant as it enters the burner, pressure of the
oxidant entering the burner, humidity of the oxidant, burner
geometry, oxidation ratio, temperature of the burner combustion
products, temperature of melt, composition of bubbles and/or foam,
and combinations thereof, and may employ a control algorithm to
control combustion temperature, treatment composition flow rate or
composition, based on one or more of these input parameters.
[0036] In the burners described in the below examples, the burner
tip may be joined to burner body using flanges. When joined in this
way, some design considerations include the thickness of the
flange, the width of the flange, and the shape of the area
surrounding the junction as this location is typically cooled with
a coolant fluid and pressure drop needs to be minimized. In
addition, when using flanges, gasket material is selected to ensure
sealing and the ability to expose the flange to an oxygen or
oxygen-enriched environment. In addition, or in certain alternative
examples, plastically deformable features may be positioned on one
or more of the flange faces to enable joint sealing.
[0037] In other examples, brazing compounds and methods may be used
to attach burner tip to burner body. Brazing allows the joining of
dissimilar metals and also allows for repairs to be made by
removing the braze material. For these examples to be successful,
the mating surfaces must be parallel or substantially so, and of
sufficient overlap to ensure that the brazing material may properly
flow between the portions of the burner tip and burner body being
joined. This may be achieved in certain examples using a flange at
right angles to both the burner tip walls 28, 30 (depicted in FIG.
1 and described in more detail below), and the conduits forming
burner body. In other examples brazing may be successfully achieved
by making the burner tip walls 28, 30 and conduits 14, 10 overlap
with sufficient gaps to allow brazing material to enter the
gaps.
[0038] Braze compounds, sometimes referred to as braze alloys, to
be useful in certain examples, must have liquidus and solidus
temperatures above the highest temperature of the burner tip. The
highest temperature of the burner tip will be a temperature equal
to the melt temperature existing in the SCM reduced by the flow of
coolant through the burner tip, as well as by the flow of
combustion gases through the burner tip. The highest temperature of
the burner tip during normal operating conditions depends on the
type of matrix being melted, which makes the selection of braze
alloy not a simple matter. For Na--Ca--Si soda-lime window glass
(Glass 1), typical melt temperature may range from about
1275.degree. C. to about 1330.degree. C.; for Al--Ca--Si E glass
having low sodium and zero boron (Glass 2), the melt temperature
may range from about 1395.degree. C. to about 1450.degree. C.; for
B--Al--Si glass, zero sodium, zero potassium, high Si (Glass 3),
the melt temperature may be about 1625.degree. C.; and for
B--Al--Ca--Si E glass used for reinforcement fiber (Glass 4), the
melt temperature maybe about 1385.degree. C. This information was
taken from Rue, D., "Energy Efficient Glass Melting--The Next
Generation Metter", p. 63, GTI Project Number 20621, March, 2008
(U.S. Dept. of Energy). Based on these temperatures, and assuming a
drop in burner tip temperature of 300.degree. C. due to coolant and
gas flow through the burner tip, Table 1 lists the possible braze
alloys that may be used.
TABLE-US-00001 TABLE 1 Braze Alloys Glass Melt Solidus Glass Type
T, (.degree. C.) Possible Braze Alloys T, (.degree. C.) 1 1275-1330
Pt 1769 Pd 1555 Ti 1670 Au/Pd (92/8, PALORO (BAU-8)) 1200 Ni/Pd
(40/60, PALNI) 1238 Pd/Co (65/35, PALCO BPD-1) 1219 Pd/Ni/Au
(34/36/30, PALNIRO 4 1135 (AMS-4785)) Cu 1083 Au 1064 2 1395-1450
Pt 1769 Pd 1555 Ti 1670 Au/Pd (92/8, PALORO (BAU-8)) 1200 Ni/Pd
(40/60, PALNI) 1238 Pd/Co (65/35, PALCO BPD-1) 1219 3 1625 Pt 1769
Ti 1670 4 1385 Pt 1769 Pd 1555 Ti 1670 Au/Pd (92/8, PALORO (BAU-8))
1200 Ni/Pd (40/60, PALNI) 1238 Pd/Co (65/35, PALCO BPD-1) 1219
Pd/Ni/Au (34/36/30 PALNIRO 4 1135 (AMS-4785))
[0039] In yet other examples, burner tip walls and conduit 14, 10
may be threaded together, in certain examples accompanied by a
sealant surface of flange upon which sealants, gaskets or O-rings
may be present. Threaded joints may be straight or tapered such as
NPT. In certain threaded examples the sealing surfaces of burner
tip walls 28, 30 may be malleable enough compared to conduits 14,
10 to deform and form their own seals, without sealants, gaskets,
or O-rings.
[0040] In still other examples, burner tip walls 28, 30 may be
interference or press fit to their respective conduit 14, 10 of
burner body 6. In these examples, the walls and/or conduits are
machined to sufficiently close tolerances to enable deformation of
one or both surfaces as the two parts are forcefully joined
together.
[0041] In yet other examples, burner tip walls 28, 30 may be
friction welded together. In these examples, either the burner tip
walls or burner body conduits, or both, may be spun and forced into
contact until sufficient temperature is generated by friction to
melt a portion of either or both materials, welding walls 28, 30 to
conduits 14, 10, respectively. These examples may include one or
more additional metals serving as an intermediate between walls 28,
30 and conduits 14, 10 to facilitate friction welding.
[0042] Specific non-limiting burner, burner tip, SCM and process
examples in accordance with the present disclosure will now be
presented in conjunction with FIGS. 1-11. The same or similar
numerals are used for the same or similar features in the various
figures. In the views illustrated in FIGS. 1-8, it will be
understood in each case that the figures are schematic in nature,
and certain conventional features are not illustrated in order to
illustrate more clearly the key features of each example.
[0043] Referring now again to the figures, FIGS. 2-11 are schematic
longitudinal cross-sectional views of non-limiting examples of
fluid-cooled portions of various examples of SC burners in
accordance with the present disclosure, while FIGS. 2A, 6A, 7A, 8A,
and 11A are detailed cross-sectional views of various burner
features described herein. Embodiment 100 illustrated schematically
in FIG. 2 includes a Pt/Rh or other corrosion and fatigue resistant
inner flange portion 50 mated with a base metal inner flange
portion 52. Flange portions 50, 52 serve to connect inner wall 28
of the burner tip to second internal conduit 14. Also illustrated
are Pt/Rh or other corrosion and fatigue resistant outer flange
portion 54 mated with a base metal outer flange portion 56. Flange
portions 54, 56 serve to connect outer wall 30 of the burner tip to
external conduit 10. Bolting is not illustrated for clarity, but it
is understood that flange portions 50, 52 are bolted together, as
are flange portions 54, 56. Bolting may be of the
threaded-bolt-and-nut type, or simply a threaded bolt that passes
completely through one flange portion and partially or completely
through the mating flange portion. Bolting of the latter type is
illustrated schematically in embodiment 200 of FIG. 4, illustrating
bolts 62, 64, 66, and 68.
[0044] The dimensions of thickness "T" and width "W" of the flange
connection formed by flange portions 50, 52 are illustrated
schematically in FIG. 2A, as well as a shape feature, "5", in
dashed lines, indicating that flange portion 50, 52 may have some
other shape to minimize pressure drop of coolant fluid through the
first and second annuli, discussed herein. Note that "W" must be a
value that allows a gap between the flange formed by flange
portions 50, 52 and the first internal conduit 12 depicted in FIG.
1 (not shown in FIG. 2) to allow warmed coolant fluid to flow out
of the fluid-cooled portion of the burner. Depending on the inner
diameter of first internal conduit 12 in the location of flange
portions 50, 52, "W" may range from 1 or more centimeters, in
certain examples up to 30 centimeters or more. "T" may range from
about 1 to about 10 centimeters, or from about 1 to about 5
centimeters. "S" may be rounded, ovoid, or angled, chamfered,
beveled, and the like.
[0045] FIG. 3 is a perspective view of the burner tip of embodiment
100, illustrating schematically the inclusion of deformable
features 58, 60 on the faces of flange portions 50, 54. In the
embodiment illustrated in FIG. 3, deformable features 58, 60 are
raised linear areas of Pt/Rh or other corrosion/fatigue resistant
material, but the format of the deformable areas may be any format
that will deform the areas to form a seal, such as a plurality of
discrete circular areas ("dots"), or dashed areas. Another
embodiment, not illustrated, is to provide machined or molded
non-deformable areas or regions on the mating faces of base metal
flange portions 52, 56 (FIG. 2) and allow these non-deformable
features to deform mating regions of corrosion/fatigue resistant
flange portions 50, 54, it being understood that the hardness
and/or ductility of the base metal are generally greater than the
hardness and/or ductility of the corrosion/fatigue resistant
material of the burner tip.
[0046] Careful selection of gasket material is a feature of
embodiment 200 illustrated in FIG. 4, which does not employ
deformable features in the flange faces. In these examples, the
gasket material used is resistant to oxygen attack, the required
resistance level being greater as the percentage of oxygen in the
oxidant stream increases. Suitable metallic gasket materials depend
on the temperature, oxygen concentration, and expected life, but
may include INCONEL (an alloy comprising 77 percent Ni, 15 percent
Cr and 7 percent Fe) and titanium. Silica fabrics and silica tapes,
such as those known under the trade designation MAXSIL (McAllister
Mills, Inc., Independence, Va.), may be used.
[0047] FIG. 5 illustrates schematically embodiment 300 employing
the same or different braze materials 70 and 72 between flange
portions 54, 56 and 50, 52, respectively. The braze materials may
be independently selected from any metallic braze materials having
a solidus temperature at least 10.degree. C., preferably at least
20.degree. C. greater than the burner tip temperature, cooled by
flowing coolant and flowing combustion gases, oxidant and/or fuel.
Some non-limiting examples are provided in Table 1 herein. In
certain examples it may not be necessary that the braze material
fill the entire width "W" of the flange joint or joints, however,
those examples having 100 percent fill are exemplary examples.
[0048] FIG. 6 illustrates schematically embodiment 400, an
alternative wherein the same or different braze materials 74, 76,
78, and 80 are used in joints that are substantially parallel to
the conduits of the burner and walls of the burner tip. Braze
materials 74, 76, 78, and 80 may be independently selected from any
metallic braze materials having a solidus temperature at least
10.degree. C., preferably at least 20.degree. C. greater than the
burner tip temperature, cooled by flowing coolant and flowing
combustion gases, oxidant and/or fuel. Some non-limiting examples
are provided in Table 1 herein. In certain examples it may not be
necessary that the braze material fill the entire overlapping area
of the joined parts, however, those examples having 100 percent
fill of the overlapping areas are exemplary examples. A more
detailed view of the braze area 74 is illustrated schematically in
FIG. 6A. In these examples, the corrosion/fatigue resistant
material of burner tip walls 28, 30 do not deform substantially,
although they may deform slightly.
[0049] FIG. 7 illustrates schematically embodiment 500, an
alternative wherein the same or different threaded joints 82, 84,
86, and 88 may be present. FIG. 7A illustrates a detailed view of
threaded joint 82, a straight thread. Tapered threads may also be
employed. As mentioned herein, threaded joint may utilize sealants,
gaskets, O-rings, and the like, or may simply utilize deformable
threads. Certain threaded examples may use a combination of two or
more of these sealing techniques.
[0050] FIG. 8 illustrates yet another embodiment 600, embodiment
600 featuring interference fittings 90, 92, 94, and 96 between
inner and outer walls 28, 30 of the corrosion/fatigue resistant
burner tip, and conduits 10 and 14 of the base material burner
body. FIG. 8A is a detailed schematic illustration of interference
fit joint 90, illustrating in a slightly exaggerated manner the
deformation of out wall 30.
[0051] FIG. 9 illustrates schematically yet another embodiment 630,
featuring inner and outer threaded rings 29, 31, O-rings 33, 35,
and weld, solder, or braze areas 37, 39. Arrows on the left portion
of FIG. 9 illustrated schematically repositioning of conduit 12 so
that insert 26 will fit between threaded rings 29, 31 upon assembly
and disassembly. Two positioning pins 27 are illustrated (more or
less than two may be used), which function to maintain a gap
between insert 26 and crown 32 for coolant flow. In embodiment 630,
burner tip inner and outer walls 28, 30, and crown 32 may be a
single noble metal piece, or may be separate pieces welded,
soldered, or brazed together. Issues of possible crossthreading of
noble metal threads of inner and outer walls 28, 30 of the burner
tip to noble metal or non-noble metal threads of rings 29, 31 may
disfavor this design, as well as the need to reposition conduit 12.
In one variation, threads may instead be press-fit locking dog
connections.
[0052] FIG. 10 illustrates schematically yet another embodiment 650
featuring lower and upper flange connectors 41, 43, which may be
fastened together using one or more clips 45. O-rings, gaskets, or
other seals 91, 93, with or without one or more grooves in flange
faces, may be used if necessary. Lower flange connector 41 may be
welded, soldered, or brazed to conduit 10 at 25, and to conduit 14
at 38. Upper flange connector 43 may be welded, soldered, or brazed
to burner tip outer wall 30 at weld or braze area 34, and to burner
tip inner wall 28 at weld or braze area 36. As with embodiment 630,
embodiment 650 may be disfavored due to the need to reposition
conduit 12 as illustrated by arrows (12a indicates possible new
position, and 12b original position), and possible need to remove
portions of insert 26, as indicated at 49, so that insert 26 will
fit between flanged areas during assembly and disassembly.
[0053] FIG. 11 illustrates schematically yet another embodiment 680
featuring locking dog or other type of shaped connectors 57, 59
(such as ribs, knurls, scallops, and the like) used to connect a
lower area 53 of burner tip outer wall 30 to a shaped "grip ring"
51, as perhaps more evident in the detail of FIG. 11A. This type of
connection, or a different type, may be used to connect a lower
area of burner tip inner wall 28 to another shaped grip ring 63.
Shaped grip ring 51 may be welded, soldered, or brazed to conduit
10 at area 55, and shaped grip ring 63 may be welded, soldered, or
brazed to conduit 14 at area 61. To effect coolant seals, areas 65
maybe welded, soldered, or brazed using appropriate materials for
the service and conduit materials. As with examples 630, 650,
embodiment 680 may require a slight repositioning of conduit 12 as
illustrated by arrows (12a indicates possible new position, and 12b
original position), however there should be less need to remove
portions of insert 26 so that insert 26 will fit between flanged
areas during assembly and disassembly, as insert 26 and conduit 12
need only clear grip rings 51, 63. Burner tip walls 28, 30, and
crown 32 may comprise noble metal. Grip rings 51, 63 may each
comprise a base metal with noble metal rolled thereon to form
shaped connectors 57.
[0054] Those of skill in the art will appreciate that examples
within the present disclosure may include a combination of the
joining methods described herein, for example, in embodiment 300
illustrated schematically in FIG. 5, braze material 72 may be
replaced with deformable features forming a seal, as described in
relation to embodiment 100 illustrated schematically in FIGS. 2-3.
Another embodiment may include, for example, interference fittings
92, 94 between second internal conduit 14 and inner wall 28 as
illustrated schematically in FIG. 8, and brazed joints 74, 80, as
illustrated schematically in FIG. 6. Yet other examples may include
flange joints formed by flange portions 50, 52 and interference
fittings 90, 96. Other various combinations of the techniques of
joining burner tips and burner bodies of dissimilar metals
disclosed herein are deemed within the present disclosure.
[0055] Those of skill in the art will also appreciate that outside
of the burners described herein the warmed heat transfer fluid
would be cooled so that it may be reused. As may also be
appreciated, burner examples described herein define a mixing
region 150 (FIG. 8) where fuel "F" and oxidant "0" mix, the mixing
region 150 being partially formed by the through passage through
burner tip, defined by burner tip inner wall 28. In certain
examples, fuel emanates from the distal end of central conduit 15
(FIG. 1), and oxidant traverses through a third annulus 19 between
central conduit 15 and second internal conduit 14, however, as
mentioned herein, these flows could be changed so that fuel
traverses third annulus 19 and oxidant traverses through central
conduit 15.
[0056] The thickness of crown 32 and inner and outer walls 28, 30
in the various examples illustrated herein is not critical, and
need not be the same for every region of the crown and walls.
Suitable thicknesses may range from about 0.1 cm to about 1 cm, or
larger. It is theorized there may be a balance between corrosion
and fatigue resistance, and thickness, with the thickness
requirement generally being increased if the "cortigue" resistance
of the crown and/or wall material is reduced. Thicker crowns and
walls, or thicker regions of crowns and walls, will generally be
stronger and exhibit more fatigue resistance, but may be more
difficult to install, for example if deformable interference
fittings are to be employed.
[0057] Regardless of the types of structure used to join the burner
tip to the burner body, several examples of which are described
above, it has been discovered that the burners or portions thereof
may be subjected to one or more post-manufacturing processes that
may reduce fatigue points on those structures or otherwise improve
the microstructure thereof. These post-manufacturing processes may
be performed before or after the portions of the burner are joined.
In that case, the processes may be performed on either or both of
the burner tip or the burner body, either before or after these two
elements are joined at flanges, welds, or other structures.
[0058] FIGS. 12A and 12B are a view and an enlarged view of a
burner surface 200 and are described simultaneously. FIG. 12A,
depicts a burner surface at approximately 20.times. magnification,
while FIG. 12B depicts a burner surface at 200.times.
magnification, to further illustrate the characteristics described
herein. Common fatigue points are evident in FIGS. 12A and 12B,
where machining lines and post-machining surface scratches may
become mechanical or thermal fatigue crack initiation sites during
service life of the burner. A plurality of machining lines 202 are
depicted, substantially parallel to the machining line arrow 204.
Additionally, a plurality of surface scratches 206 are depicted
substantially parallel to surface scratch line arrow 208. Both
machining lines 202 and surface scratches 206 may propagate into
fatigue cracks. For example, fatigue crack 210 is depicted
emanating from machining line 202a, while fatigue crack 212 is
depicted emanating from surface scratch 206a. Although the
measurements may vary from burner to burner, surface scratches and
common machined component surface finish features are typically
about 10 to about 100 microns in depth, and vary depending on
machining technology and machine settings. Within the burner,
stress exists not only through the material thickness, but also at
the burner's surface. A rough surface condition results in stress
risers at any discontinuity, those stress risers result in
decreased time to onset of fatigue cracks. Once such fatigue cracks
210, 212 are initiated, they deepen and lengthen due to the
burner's volatile thermal conditions and resulting stress
cycling.
[0059] It has been discovered, however, that polishing of the
burner after manufacture may mitigate the onset of fatigue
initiation. The polishing decreases the microscopic surface
variation, and thus delays the onset of fatigue. The portions of
the burner that may benefit from polishing to remove surface
discontinuities include any areas of the burner that are exposed to
the volatile thermal conditions in the SCM. As such, polishing of
the toroidal burner tip may significantly improve performance.
However, polishing of the burner body, especially the areas thereof
disposed proximate the burner tip or the connection points to the
burner tip, may also improve performance. In examples, a preferred
surface finish is less than about 1.0 micron or less than about 0.5
micron. More specifically, the surface finish may be between about
1.0 to about 0.1 micron. The polishing may have a circumferential
or multiple random orientations of the microscopic as-finished
surface texture. However, any amount of finishing which reduces
surface roughness from the as-machined or as-scratched condition is
beneficial, whether circumferential or randomly oriented.
[0060] The polishing processes reduce the surface roughness of the
burner (or a portion thereof) from a first, higher surface
roughness, to a second, lower surface roughness. It may be
advantageous to measure the first surface roughness across an
entire area of the burner, or discrete portions thereof (either
randomly or specifically). This enables a determination of an
average first surface roughness. As the polishing process proceeds,
the roughness of the same surface may be measured (again, across
the entire area of the burner, or portions thereof). Re-measuring
of the surface roughness may determine an average second surface
roughness. If the average second surface roughness is still not
desirable, polishing of the burner may continue until the desired
surface roughness is achieved. The amount of polish may be measured
based on surface roughness measurements, surface features
measurements, other measurements, or combinations thereof. One or
more polishing operations (separated by measuring operations to
determine surface finish) may reduce the average surface roughness
such that a post-polishing surface roughness is about 5% of the
pre-polishing surface roughness. In other examples, polishing
operations may reduce the average surface roughness such that a
post-polishing surface roughness is about 1% of the pre-polishing
surface roughness. A post-polishing surface roughness about 0.1% of
the pre-polishing surface roughness may also be desirable.
[0061] FIG. 13 depicts a method 300 of polishing a portion of a
burner after manufacture. The method 300 begins with disposing a
portion of an SCM burner in a vise in operation 302. Securing in a
vise specifically is not required. Instead, the portion to be
polished must be generally fixed in position such that it resists
movement during polishing processes. In examples, the portion of
the burner secured is the toroidal tip, although other portions of
the burner, e.g., the burner body, could be secured for polishing
purposes. Before polishing begins, the portion of the burner may be
characterized as having an average first surface roughness across
an area of the burner. The area may be the entire exposed surface
of the portion of the burner to be polished. In other examples, the
area may be a defined area contained within a boundary that may be
measured before and after polishing to quantify results of
polishing. In operation 304, the portion of the burner is polished
to an average second surface roughness across the area of the
portion of the burner. Of course, the average second surface
roughness is less than the average first surface roughness. Example
heights of surface features before and after polishing are
described above. When comparing the two surface roughnesses, the
differences may be significant as described above. It is often
advantageous to perform operation 304 in a random pattern about the
surface to be polished. Circumferential polishing is also
contemplated.
[0062] FIGS. 14A and 14B depict microstructures of cast precious
metal samples 400, 400' before and after hot isostatic pressing
processes, respectively. Post-processing of a burner or a part
thereof (e.g., a burner body or a burner tip), as part of the
manufacturing process improves the microstructure of the processed
part by minimizing morphological differences through the part and
eliminating defects of the exposed part, providing operational
service life or mechanical property advantage. Post-manufacturing
processing (as used herein "post-processing") includes heat
treatments, hot-isostatic pressing (HIP), and similar timed
temperature and/or pressure treatments. These processes, described
in the context of FIGS. 14A, 14B, and 15, may be performed before
or after the polishing processes described above. Alternatively,
the polishing processes need not be performed at all for a part of
a burner to benefit from the heat treatment process described
herein.
[0063] By subjecting the burner part to post-processing, part life
is extended by manipulating the size, aspect ratio, range, and/or
orientation of the grains, as well as by eliminating voids,
chemical micro-segregation, and other defects within the
microstructure of the processed part. This helps the part withstand
the volatile thermal environment and fatigue failures which may
onset therein. In an un-processed part, defects and grains which
are columnar (especially when columnar grains are aligned
perpendicular to stress) enable rapid crack initiation and
propagation while experiencing thermal and/or mechanical loads
during service. Therefore, service life and mechanical properties
such as ductility and strength are improved (and therefore are more
accurately tailored) to the specific condition of the part during
service. Another advantage is that post-processing of the part does
not significantly change its geometry, therefore little or no
additional machining is required to meet dimensional
specifications.
[0064] In welded areas, morphological differences between the weld
metal and the base metal provides higher probability for failure at
the fusion line or heat affected zone, therefore post-processing
any parts of the burner that have been welded minimizes or
eliminates these differences, which greatly reduces the chances for
failure, and improves the integrity of that part, therefore
extending service life. The post-processing technologies described
herein may be applied to metallic materials such as superalloy,
precious, and other non-precious metal systems. The technology may
be further applied to most any forming technologies including cast,
wrought, forged, pressed, rolled, direct metal laser sintered, or
other methods which generate less-than-desired morphology or
non-uniformity within the burner. This also applies to both the raw
part and within the burner around any repaired, welded, jointed, or
otherwise discontinuous morphology as a result of the means used to
manufacture the burner. In the context of SCM burners, the
technology is particularly desirable since those burners are
typically formed from cast precious metal parts. Cast precious
metal display superior ductility and other properties that provide
relatively high thermal shock resistance. Such precious metals also
display risk of inferior attributes due to the localized
non-uniformities (such as casting gates) required to form a cast
burner.
[0065] Other advantages of post-processing are that the burner may
be cast, weld-repaired, welded, or otherwise formed in ways that
result in undesirable non-uniform or unintended voids or defects in
the microstructure. Such burners, and especially the areas of the
burner that have been welded, may be post-processed to eliminate
such defects and still provide advantageous microstructure for
improved part performance. Types of post-processing include heat
treatments that approach a melting temperature of the metal, or at
least at a combination of sufficient temperatures and times to
promote nucleation, recrystallization, and grain growth-in. By
utilizing these treatments, the microstructure is managed to a
preferred condition. In an example, the post processing is hot
isostatic pressing (HIP) that provides both the desired
microstructure and also causes any defects or voids in the
microstructure to be closed while grains recrystallize. This, in
essence, mends any defects, including those caused by welding. Any
such mended defects are one less potential failure site of the
component during its life in the volatile thermal and mechanical
loading environment of an SCM system.
[0066] FIG. 14A depicts a microstructure of a metal sample 400,
prior to any post-processing. In this as-cast condition, the sample
400 displays unfavorable elongated grains 402 protruding inwards
from the exterior surface, and also exhibits a high concentration
of voids 404. In FIG. 14B, a post-processed sample 400' is
depicted. The sample 400' has been subjected to HIP, which results
in the grains 402' being no longer elongated inwards from the outer
surface. Virtually all voids have been eliminated.
[0067] Table 2 depicts a range of HIP parameters, as well as
parameters that produced particularly desirable results (identified
as Example 1). In Example 1, a burner formed by a precious metal
having a combination of about 80% Pt and about 20% Rh was utilized
and subjected to HIP processing. Burners manufactured from
combinations of Pt and Rh are particularly desirable because such
combinations maintain a single phase regardless of temperature.
This single phase performance may apply to any percentage
combination of Pt and Rh (e.g., 0%-100% Pt through 100%-0% Rh). For
example, burners manufactured from about 70% Pt and about 30% Rh,
as well as burners manufactured from about 90% Pt and about 10% Rh,
are expected to perform similarly. Other precious metals having
different percentages of Pt and Rh are contemplated for
burners.
TABLE-US-00002 TABLE 2 HIP parameters for burner post-processing
Parameter Range Example 1 Temperature 2200 to 3000.degree. F.
2600.degree. F. Time 100 to 1000 minutes 365 minutes Pressure
20,000 to 50,000 psi 30,000 psi
[0068] It has also been discovered that multiple post-processing
cycles (e.g., HIP cycles) may be performed on a burner to achieve
more desirable results. Table 3, below, depicts example pressures,
temperature, and times for HIP processing of test parts that have
been subjected to both laser welding and gar tungsten arc welding
(GTAW), for multiple HIP cycles. Laser welding and GTAW produce
different defects to the microstructure adjacent the weld. For
example, laser welding causes a significant number of voids
directly adjacent a very fine weld area, whereas GTAW creates a
significant number of elongated grains over a fairly large area,
with a large number of voids disposed just outside the area of
grains. Removing these defects through HIP processing helps
increase the life of the part. Prior to each HIP cycle,
nondestructive defect detection techniques (such as dye penetrant
inspection and radiography) may be performed to identify any
defects for potential weld repair. This multi-step process brings
additional mending to defects in the microstructure. Care should be
taken so as not to cause overly large grains (and direct paths
through grain boundaries) for cracks to propagate.
TABLE-US-00003 TABLE 3 Example HIP parameters Thickness No. Sample
[in] Pressure [psi] T [.degree. F.] t [min] 1 As Cast 0.06 n/a n/a
n/a 2 As Cast 0.09 n/a n/a n/a 3 HIP-1 0.06 30,000 +/- 250 2417 +/-
25 365 +/- 15 2417 4 HIP-1 0.09 30,000 +/- 250 2417 +/- 25 365 +/-
15 2417 5 HIP-1 0.06 29,750 +/- 250 2600 +/- 25 365 +/- 15 2600 6
HIP-1 0.09 29,750 +/- 250 2600 +/- 25 365 +/- 15 2600 7 HIP-2 0.06
30,000 +/- 250 2417 +/- 25 365 +/- 15 2417 8 HIP-2 0.09 30,000 +/-
250 2417 +/- 25 365 +/- 15 2417 9 HIP-2 0.06 29,750 +/- 250 2600
+/- 25 365 +/- 15 2600 10 HIP-2 0.09 29,750 +/- 250 2600 +/- 25 365
+/- 15 2600
[0069] In the above Table 3, Samples 1 and 2 were as-cast test
pieces having two different thicknesses that were not subjected to
any HIP processing. Samples 3-5 are test parts having thicknesses
as indicated and subjected to HIP processing with under the
parameters indicated. All of Samples 3-5 were welded with both
laser and GTAW welds. After one cycle of HIP processing, testing
was performed to observe the remaining defects in the part.
Proximate the laser weld, a significant number of the voids had
been removed from the part and some voids had combined into single,
rounder voids. This indicated that further processing would likely
completely remove these rounder voids from the material. Proximate
the GTAW welds, elongated grains had become more equiaxed and
regular in shape, and very few voids were present. After subjecting
the samples to a second cycle of HIP processing (Samples 7-10),
nearly all voids were removed from the samples proximate the laser
welds, while the grains proximate the GTAW weld were further
equiaxed and the voids eliminated.
[0070] FIG. 15 depicts a method 500 of hot isostatic processing a
part after manufacture. The method 500 begins with operation 502,
where a part is disposed within a pressure vessel. The burner part
may be the burner body, the toroidal burner tip, or the burner
itself (e.g., the combined burner tip and burner body). The part
has a first microstructure defined by, among other characteristics,
a first number of voids. The first microstructure may also be
defined by elongated grains or other structures. Once the part is
disposed in the pressure vessel, the vessel is sealed and filled
with an isostatic gas such as argon or another inert gas, as in
operation 504. In operation 506, the vessel is pressurized and in
operation 508, the vessel is heated. These operations may occur
substantially simultaneously. Example pressures may be between
about 20,000 psi and about 50,000 psi; between about 25,000 psi and
about 40,000 psi; and about 30,000 psi. Examples temperatures may
be between about 2200 degrees F. to about 3000 degrees F.; between
about 2450 degrees F. to about 2750 degrees F.; and about 2600
degrees F. The part may be held at the elevated temperature and
pressure for a time sufficient to produce a second microstructure
in the burner part. The second microstructure is defined by a
second number of voids that is less than the first number of voids.
As with the first microstructure, the second microstructure may
also be characterized by elongated grains or other structures.
[0071] In testing performed on a burner part prior to HIP
processing, it has been determined that the size and number of
voids are significant. Testing has revealed that, prior to
processing, voids can be as much as 500 microns in diameter. Void
fraction in the first microstructure (again, prior to processing)
can be as high as 20% or higher in welds. After HIP processing,
void fraction can be reduced to significantly less than 1%
(effectively 0%). Any remaining voids, however infrequent, may be
much less than 5 microns in diameter. Regarding microstructure, the
first microstructure can be dictated at least in part by the
thickness and shape of the part in the region of interest, and the
manufacturing methods to form the part. In the example above in
FIG. 14A, the first microstructure reveals highly columnar grains
before HIP. After HIP, the second microstructure is significantly
more equiaxed and regular in shape. Specific analytical tools are
known to quantify grain size, aspect ratio, size distribution,
etc., and such tools would be known to a person of skill in the
art. In general, the goal after HIP is to produce a microstructure
that is more equiaxed and regular, with fewer voids, grains having
more rounded edges, etc. As such, the microstructure is more
normalized and is not simply heterogeneous with voids and defects.
A more normalized microstructure displays advantages over a
microstructure having elongated grains, which are unstable and have
large driving force due their geometry to re-form at high
temperatures. As such, elongated grains more easily form cracks,
since the grain boundaries are highly aligned for cracks to
propagate. Sufficient times to achieve the second microstructure
may be between about 100 minutes to about 1000 minutes; between
about 200 minutes to about 600 minutes; and about 365 minutes.
[0072] Once the appropriate amount of time has elapsed, the vessel
is depressurized and cooled. Thereafter, in operation 510, the
burner part is removed from the vessel. As described above, the
part may be non-destructively tested so as to identify a burner
defect, operation 512. In operation 514, defects may be
weld-repaired. In operation 516, if desired, the part of the burner
may be returned to the vessel and operations 502-508 repeated.
[0073] FIG. 16 depicts a side sectional view of a melter system 600
that may be utilized in conjunction with the examples of the
burners described above. The melter system 600 is a submerged
combustion melter (SCM) and is described in more detail in U.S.
Patent Application Publication No. 2013/0283861, the disclosure of
which is hereby incorporated by reference herein in its entirety.
Melter apparatus or melt vessel 601 of FIG. 6 includes a floor 602,
a roof or ceiling 604, a feed end wall 606A, a first portion of an
exit end wall 606B, and a second portion of the exit end wall 606C.
Each of the floor 602, the roof 604, and walls 606A, 606B, and 606C
comprise a metal shell 617 and a refractory panel 609, some or all
of which may be fluid-cooled. Exit end wall portion 606C may form
an angle with respect to a skimmer 618.
[0074] The melt vessel 601 may be fluid cooled by using a gaseous,
liquid, or combination thereof, heat transfer media. In certain
examples, the wall may have a refractory liner at least between the
panels and the molten glass. Certain systems may cool various
components by directing a heat transfer fluid through those
components. In certain examples, the refractory cooled-panels of
the walls, the fluid-cooled skimmer, the fluid-cooled dam, the
walls of the fluid-cooled transition channel, and the burners may
be cooled by a heat transfer fluid selected from the group
consisting of gaseous, liquid, or combinations of gaseous and
liquid compositions that function or are capable of being modified
to function as a heat transfer fluid. Different cooling fluids may
be used in the various components (e.g., wall portions of the melt
vessel 601, the burners 612, etc.), or separate portions of the
same cooling composition may be employed in all components. Gaseous
heat transfer fluids may be selected from air, including ambient
air and treated air (for air treated to remove moisture), inert
inorganic gases, such as nitrogen, argon, and helium, inert organic
gases such as fluoro-, chloro- and chlorofluorocarbons, including
perfluorinated versions, such as tetrafluoromethane, and
hexafluoroethane, and tetrafluoroethylene, and the like, and
mixtures of inert gases with small portions of non-inert gases,
such as hydrogen. Heat transfer liquids may be selected from inert
liquids, which may be organic, inorganic, or some combination
thereof, for example, salt solutions, glycol solutions, oils and
the like. Other possible heat transfer fluids include water, steam
(if cooler than the oxygen manifold temperature), carbon dioxide,
or mixtures thereof with nitrogen. Heat transfer fluids may be
compositions including both gas and liquid phases, such as the
higher chlorofluorocarbons.
[0075] The melt vessel 601 further includes an exhaust stack 608,
and openings 610 for submerged combustion burners 612, which create
during operation a highly turbulent melt matrix indicated at 614.
Examples of SCM burners 612 are described above. Highly turbulent
melt matrix 614 may have an uneven top surface 615 due to the
nature of submerged combustion. An average level 607 is illustrated
with a dashed line. In certain examples, burners 612 are positioned
to emit combustion products into molten matrix in the melting zone
614 in a fashion so that the gases penetrate the melt generally
perpendicularly to floor 602. In other examples, one or more
burners 612 may emit combustion products into the melt at an angle
to floor 602.
[0076] In an SCM, combustion gases emanate from burners 612 under
the level of a molten matrix. The burners 612 may be floor-mounted,
wall-mounted, or in melter examples comprising more than one
submerged combustion burner, any combination thereof (for example,
two floor mounted burners and one wall mounted burner). These
combustion gases may be substantially gaseous mixtures of combusted
fuel, any excess oxidant, and combustion products, such as oxides
of carbon (such as carbon monoxide, carbon dioxide), oxides of
nitrogen, oxides of sulfur, and water. Combustion products may
include liquids and solids, for example soot and unburned liquid
fuels.
[0077] At least some of the burners may be mounted below the melt
vessel, and in certain examples the burners may be positioned in
one or more parallel rows substantially perpendicular to a
longitudinal axis of the melt vessel. In certain examples, the
number of burners in each row may be proportional to width of the
vessel. In certain examples the depth of the vessel may decrease as
width of the vessel decreases. In certain other examples, an
intermediate location may comprise a constant width zone positioned
between an expanding zone and a narrowing zone of the vessel, in
accordance with U.S. Patent Application Publication No.
2011/0308280, the disclosure of which is hereby incorporated by
reference herein in its entirety.
[0078] Returning to FIG. 6, the initial raw material may be
introduced into melt vessel 601 on a batch, semi-continuous or
continuous basis. In some examples, a port 605 is arranged at end
606A of melt vessel 601 through which the initial raw material is
introduced by a feeder 634. In some examples, a batch blanket 636
may form along wall 606A, as illustrated. Feed port 605 may be
positioned above the average matrix melt level, indicated by dashed
line 607. The amount of the initial raw material introduced into
melt vessel 601 is generally a function of, for example, the
capacity and operating conditions of melt vessel 601 as well as the
rate at which the molten material is removed from melt vessel
601.
[0079] The initial raw material may include any material suitable
for forming a molten matrix, such as glass and/or inorganic
non-metallic feedstocks such as rock (basalt) and mineral wool
(stone wool). With regard to glass matrices, specifically,
limestone, glass, sand, soda ash, feldspar and mixtures thereof may
be utilized. In one example, a glass composition for producing
glass fibers is "E-glass," which typically includes 52-56%
SiO.sub.2, 12-16% Al.sub.2O.sub.3, 0-0.8% Fe.sub.2O.sub.3, 16-25%
CaO, 0-6% MgO, 0-10% B.sub.2O.sub.3, 0-2% Na.sub.2O+K.sub.2O,
0-1.5% TiO.sub.2 and 0-1% F.sub.2. Other glass compositions may be
used, such as those described in U.S. Published Patent Application
No. 2008/0276652, the disclosure of which is hereby incorporated by
reference herein in its entirety. The initial raw material may be
provided in any form such as, for example, relatively small
particles.
[0080] As noted herein, submerged combustion burners may produce
violent turbulence of the molten matrix and may result in a high
degree of mechanical energy (e.g., vibration V in FIG. 6) in the
submerged combustion melter that, without modification, is
undesirably transferred to the conditioning channel. Vibration may
be due to one or more impacts from sloshing of the molten matrix,
pulsing of the submerged combustion burners, popping of large
bubbles above submerged burners, ejection of the molten matrix from
main matrix melt against the walls and ceiling of melt vessel 601,
and the like. Melter exit structure 628 comprises a fluid-cooled
transition channel 30, having generally rectangular cross-section
in melt vessel 601, although any other cross-section would suffice,
such as hexagonal, trapezoidal, oval, circular, and the like.
Regardless of cross-sectional shape, fluid-cooled transition
channel 630 is configured to form a frozen matrix layer or highly
viscous matrix layer, or combination thereof, on inner surfaces of
fluid-cooled transition channel 630 and thus protect melter exit
structure 628 from the mechanical energy imparted from the melt
vessel 601 to melter exit structure 628. This disclosure described
some aspects of the present technology with reference to the
accompanying drawings, in which only some of the possible aspects
were shown. Other aspects can, however, be embodied in many
different forms and should not be construed as limited to the
aspects set forth herein. Rather, these aspects were provided so
that this disclosure was thorough and complete and fully conveyed
the scope of the possible aspects to those skilled in the art.
[0081] Although specific aspects were described herein, the scope
of the technology is not limited to those specific aspects. One
skilled in the art will recognize other aspects or improvements
that are within the scope of the present technology. Therefore, the
specific structure, acts, or media are disclosed only as
illustrative aspects. The scope of the technology is defined by the
following claims and any equivalents therein.
* * * * *