U.S. patent application number 13/415716 was filed with the patent office on 2012-09-13 for flare tip having internal spin vanes.
This patent application is currently assigned to HONEYWELL INTERNATIONAL INC.. Invention is credited to Bryan Beck, Matthew Martin, Richard Ray Martin, Walter Swander.
Application Number | 20120231399 13/415716 |
Document ID | / |
Family ID | 46795875 |
Filed Date | 2012-09-13 |
United States Patent
Application |
20120231399 |
Kind Code |
A1 |
Beck; Bryan ; et
al. |
September 13, 2012 |
FLARE TIP HAVING INTERNAL SPIN VANES
Abstract
A flare tip for the burning and disposal of combustible waste
gases including internal spin vanes is provided. By providing a
plurality of internal spin vanes within the waste gas inlet of a
flare tip, the efficiency of combustion of waste gas can be
increased.
Inventors: |
Beck; Bryan; (Tulsa, OK)
; Martin; Richard Ray; (Tulsa, OK) ; Martin;
Matthew; (Tulsa, OK) ; Swander; Walter;
(Tulsa, OK) |
Assignee: |
HONEYWELL INTERNATIONAL
INC.
Morristown
NJ
|
Family ID: |
46795875 |
Appl. No.: |
13/415716 |
Filed: |
March 8, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61452005 |
Mar 11, 2011 |
|
|
|
Current U.S.
Class: |
431/5 ;
431/202 |
Current CPC
Class: |
F23G 5/32 20130101; F23G
7/085 20130101 |
Class at
Publication: |
431/5 ;
431/202 |
International
Class: |
F23G 7/08 20060101
F23G007/08 |
Claims
1. A flare apparatus for burning and disposal of combustible waste
gases, the flare apparatus comprising: a flare tip comprising a
waste gas conduit having a base portion defining a waste gas inlet
and an upper portion defining a waste gas outlet, the base portion
having an outer diameter smaller than an outer diameter of the
upper portion; and a plurality of spin vanes for inducing a spin on
the waste gas entering the flare tip disposed within the base
portion, the spin vanes disposed at an angle relative to a
longitudinal axis of the flare tip.
2. The flare apparatus according to claim 1, further comprising a
plurality of combustion air conduits for supplying combustion air
disposed within and in fluid communication with the upper portion
of the flare tip.
3. The flare apparatus according to claim 1, further comprising an
outer shell defining a plenum surrounding the flare tip.
4. The flare apparatus according to claim 1, wherein the flare tip
is coupled to and in fluid communication with a flare stack.
5. The flare apparatus according to claim 1, wherein the outer
shell has a generally cylindrical lower portion and a frustoconical
upper portion defining an opening wherein the opening of the upper
portion of the outer shell is elevated relative to the waste gas
outlet defined by the upper portion of the flare tip.
6. The flare apparatus according to claim 1, wherein the angle of
the spin vanes relative to the longitudinal axis of the flare tip
ranges is less than about 60.degree..
7. The flare apparatus according to claim 1, wherein the angle of
the spin vanes relative to the longitudinal axis of the flare tip
ranges from about 20.degree. to about 60.degree..
8. The flare apparatus according to claim 1, wherein the angle of
the spin vanes relative to the longitudinal axis of the flare tip
is about 30.degree..
9. The flare apparatus according to claim 1, wherein the plurality
of spin vanes comprises 2 to 36 spin vanes.
10. The flare apparatus according to claim 1, wherein the plurality
of spin vanes comprises 24 to 36 spin vanes.
11. The flare apparatus according to claim 1, wherein the plurality
of spin vanes comprises 12 to 24 spin vanes.
12. The flare apparatus according to claim 1, wherein the plurality
of spin vanes comprises 2 to 12 spin vanes.
13. The flare apparatus according to claim 1, wherein a width of
the spin vanes ranges from about 8 inches to about 18 inches.
14. The flare apparatus according to claim 1, wherein a width of
each of the spin vanes ranges from about 4 inches to about 8
inches.
15. The flare apparatus according to claim 1, wherein a width of
each of the spin vanes ranges from about 1 inch to about 4
inches.
16. A flare apparatus having a flare tip and a number of
distributing features for distributing a waste gas stream in the
flare tip.
17. A method comprising: receiving a waste gas flow; distributing
the waste gas flow within a flare tip.
18. The method of claim 17, wherein the distributing step includes
inducing a spin in the waste gas flow.
Description
[0001] This application claims the benefit of U.S. Provisional
Patent Application No. 61/452,005, filed Mar. 11, 2011, and
entitled "Flare Tip Having Internal Spin Vanes". U.S. Provisional
Patent Application No. 61/452,005, filed Mar. 11, 2011, is hereby
incorporated by reference.
TECHNICAL FIELD
[0002] The disclosure relates generally to a flare tip for the
burning and disposal of flammable waste gases and more
particularly, to a flare tip including internal spin vanes.
BACKGROUND
[0003] Gas flares are commonly located at production facilities,
refineries, processing plants, and the like for disposing of
flammable waste gases and other flammable gas streams that are
diverted due to venting requirements, shut-downs, upsets, and/or
emergencies. Such flares are often operated in a smokeless or near
smokeless manner, which can be largely achieved by making sure that
the flammable gas to be discharged and burned ("flare gas") is
admixed with enough air to sufficiently oxidize the gas.
[0004] A typical flare apparatus includes a flare stack, which can
extend high above the ground, and a flare tip mounted on the flare
stack. An elevated flare tip is a device often used in industrial
applications to burn combustible materials in an elevated location.
Advanced flare tips use various methods in an attempt to provide
sufficient oxygen in the combustion zone of the flare tip to help
minimize the formation of smoke. In some larger flare tips, the
exit of the flare tip is larger, and sometimes much larger, than
the size of the waste gas riser that supplies the waste gas that
includes the combustible material. Because the diameter of the
flare tip is often larger than the flare riser, the waste gas
velocity can be much higher in the center of the flare tip than at
the perimeter of the flare tip. The higher flow of waste gas in the
center of the flare tip can increase the oxygen requirements at the
center of the flare tip, which can increase the propensity of the
flare to smoke.
SUMMARY
[0005] The disclosure relates generally to a flare tip for the
burning and disposal of combustible gases and more particularly, to
a flare tip including internal spin vanes.
[0006] In an illustrative embodiment, a flare apparatus for burning
and disposal of combustible waste gases is provided. The flare
apparatus may include a flare tip having a waste gas conduit. The
waste gas conduit may have a base portion defining a waste gas
inlet and an upper portion defining a waste gas outlet. In some
cases, the base portion of the waste gas conduit can have an outer
diameter that is smaller than an outer diameter of the upper
portion, but this is not required. The flare apparatus may include
a plurality of spin vanes for inducing a spin in the waste gas
entering the flare tip. In some instances, the plurality of spin
vanes may be disposed within the base portion of the waste gas
conduit. The spin vanes can be disposed at an angle relative to a
longitudinal axis of the flare tip. The number, size, and angle of
the spin vanes may vary depending upon a variety of factors
including, for example, waste gas composition, waste gas flow rate,
waste gas pressure, the available smokeless medium, the allowable
heat and grade, as well as other factors. The flare apparatus may
also include an outer shell defining a plenum surrounding the flare
tip, if desired.
[0007] The above summary is not intended to describe each and every
example or every implementation of the disclosure. The Description
that follows more particularly exemplifies various illustrative
embodiments.
BRIEF DESCRIPTION OF THE FIGURES
[0008] The following description should be read with reference to
the drawings. The drawings, which are not necessarily to scale,
depict selected illustrative embodiments and are not intended to
limit the scope of the disclosure. The disclosure may be more
completely understood in consideration of the following description
of various illustrative embodiments in connection with the
accompanying drawings, in which:
[0009] FIG. 1 is a partial, cross-sectional view of a flare tip in
accordance with an illustrative embodiment of the present
disclosure;
[0010] FIG. 2 is a side, cross-sectional view of a flare tip in
accordance with an illustrative embodiment of the present
disclosure;
[0011] FIG. 3 is a detailed, plan view of a flare tip base
including a plurality of internal spin vanes in accordance with an
illustrative embodiment of the present disclosure;
[0012] FIG. 4 is an end, cross-sectional view of a flare tip in
accordance with an illustrative embodiment of the present
disclosure;
[0013] FIGS. 5A-5D show the burn profiles of a waste gas stream
using a modified flare tip including spin vanes;
[0014] FIGS. 5E-5F show the velocity contours within a waste gas
stream produced using the same modified flare tip used to produce
the burn profiles of FIGS. 5A-5D.
[0015] FIGS. 6A-6D show the burn profiles of a waste gas stream
using a flare tip including spin vanes and a twenty-four inch
velocity seal;
[0016] FIGS. 6E-6F show the velocity contours within a waste gas
stream produced using the same modified flare tip used to produce
the burn profiles of FIGS. 6A-6D; and
[0017] FIGS. 6G-6H show the velocity contours within the waste gas
stream measured just above the velocity seal of the same modified
flare tip used to produce the burn profiles and velocity profiles
of FIGS. 6A-6F.
DESCRIPTION
[0018] The following description should be read with reference to
the drawings, in which like elements in different drawings are
numbered in like fashion. The drawings, which are not necessarily
to scale, depict selected illustrative embodiments and are not
intended to limit the scope of the disclosure. Although examples of
construction, dimensions, and materials are illustrated for the
various elements, those skilled in the art will recognize that many
of the examples provided have suitable alternatives that may be
utilized.
[0019] FIGS. 1-4 show various cross-sectional views of an
illustrative flare apparatus 10. As shown in FIGS. 1 and 2, the
flare apparatus 10 may include a flare tip 14 having a base portion
18 defining a waste gas inlet 22 and an upper portion 26 defining a
waste gas outlet 30. In certain embodiments, such as shown in FIGS.
1 and 2, the base portion 18 has an outer diameter smaller than an
outer diameter of the upper portion 26, but this is not
required.
[0020] As best shown in FIG. 3, a plurality of spin vanes 36 may be
disposed within, for example, the base portion 18. The spin vanes
36 may induce a spin on the waste gas entering the flare tip 14
through the waste gas inlet 22. The energy needed to produce the
spin comes from the kinetic energy present in the flowing waste
gas. In many instances, no additional equipment is necessary to
induce a spin on the waste gas entering the flare tip 14.
[0021] In many flare tip designs, more oxygen for combustion is
available near the perimeter of the flare tip 14 than is available
near the center of the flare tip 14. When a spin is induced in the
waste gas entering the flare tip 14, the resulting centrifugal
action may distribute the waste gas more toward the outer edges or
perimeter of the flare tip 14. By shifting waste gas flow closer to
the perimeter of the flare tip 14, where more oxygen is often
available, the propensity for the waste gas to smoke when burned
may be reduced.
[0022] Flare tips are often customized depending upon the
application, and it is contemplated that the number, size, and
angle of the spin vanes 36 may vary. The number, size, and angle of
the spin vanes 36 disposed within the flare tip 14 may vary
depending upon a variety of factors including, for example: the
waste gas composition, diameter of the waste gas inlet 22, waste
gas flow velocity, waste gas pressure, the available smokeless
medium, the allowable heat and grade, as well as other factors.
[0023] In general, the larger the diameter of the waste gas inlet
22, the larger the number and/or size of the spin vanes 36 may be
used. Typically, the diameter of the waste gas inlet 22 can range
from about 8 inches to about 72 inches, depending upon the
application, but this is just an example range. Depending upon the
diameter of the waste gas inlet 22 and the amount of spin needed to
distribute the waste gas to the perimeter of the flare tip 14, the
number of spin vanes 36 disposed within the base portion 18 of the
flare tip 14 may range from, for example, 2 to 36 spin vanes. In
other embodiments, the number of spin vanes 36 can range from 24 to
36 spin vanes, from 12 to 24 spin vanes, and from 2 to 12 spin
vanes, or any other suitable range. In the illustrated embodiment
shown in FIGS. 1-3, eight spin vanes 36 are utilized. The size of
the spin vanes 36 can also be varied depending on, for example, the
diameter of the waste gas inlet 22 and the number of spin vanes 36
provided. In some embodiments, the width of the spin vanes 36 can
range from 1 inch to about 18 inches, but again, these are just
examples. In other embodiments, the width of the spin vanes 36 can
range from about 8 inches to about 18 inches, from about 4 to about
8 inches, and from about 1 inch to about 4 inches.
[0024] The angle relative to the longitudinal axis 40 (FIG. 2) at
which each of the spin vanes 36 are disposed within the base
portion 18 of the flare tip 14 can also vary, depending on the
application. In certain embodiments, the angle of the spin vanes 36
relative to the longitudinal axis 40 of the flare tip 14 may be
equal to or less than about 60.degree. and more particularly,
ranges from about 20.degree. to about 60.degree. or from about
20.degree. to about 40.degree.. In other embodiments, the angle of
the spin vanes 36 relative to the longitudinal axis 40 of the flare
tip 14 is about 30.degree.. Thus, it is contemplated that the angle
of the spin vanes may be any suitable value or within any suitable
range. In some cases, it is contemplated that the angle of the spin
vanes 36 may change or vary from the upstream end of the spin vanes
36 to the downstream end, while in other cases, the angle may be
constant. In some cases, waste gas composition can also affect the
angle, size and number of spin vanes 36 that are desired for a
particular application.
[0025] As shown in FIGS. 1-4, the flare apparatus 10 can also
include a one or more combustion air conduits 44 for supplying
combustion air to the flare tip 14. In some embodiments, as
illustrated, the combustion air conduits 44 may be disposed within
and in fluid communication with the upper portion 26 of the flare
tip 14. In some instances, spaces are provided between the
combustion air conduits 44 to, for example, allow the waste gas to
travel up and past the combustion air conduits 44. In some
embodiments, the combustion air conduit(s) 44 may be provided
external to, but still in fluid communication with the flare tip
14. The combustion air conduits 44 can be fabricated from, for
example, carbon steel or stainless steel piping, and may be capable
of delivering air and/or steam to the flare tip 14, depending upon
the application.
[0026] In some instances, the flare apparatus 10 may include an
outer shell 48 defining a plenum 52 surrounding the flare tip 14
(FIGS. 1 and 2), but this is not required. According to one
embodiment, as illustrated, the outer shell 48 can include a
generally cylindrical lower portion 52 and a frustoconical upper
portion 56 defining an opening 60. In certain embodiments, such as
shown in FIG. 1, the opening 60 of the upper portion 56 of the
outer shell 48 can be elevated relative to the waste gas outlet 30
defined by the flare tip 14. In some cases, atmospheric air can be
forced through the plenum 52 surrounding the flare tip 14.
[0027] Spin vanes, as discussed herein, may be combined with other
tips of flare tip internal structures such as, for example,
velocity seals.
EXAMPLES
Example 1
[0028] A computational fluid dynamic study (CFD) of the combustion
of a propane gas stream was conducted using a modified flare tip
including five-inch wide internal spin vanes. The operating
parameters utilized to conduct this study are provided in Table
1.
TABLE-US-00001 TABLE 1 Parameter Propane Flow 60,000 lbs/hr Propane
Temp 100.degree. F. Air Flow 100,000 ACFM Air Temp 100.degree. F.
Wind Speed/Direction 10 ft/sec left-right
[0029] FIGS. 5A-5D show the burn profiles of a combustion gas
stream using the modified flare tip. FIGS. 5A-5B show the air
volume fraction within the gas stream, and FIGS. 5C-5D show the
volume fraction of propane within the combustion gas stream. FIGS.
5E-5F show the velocity contours within the gas stream produced
using the modified flare tip.
[0030] The burn profiles shown in FIGS. 5A-5F exhibit improved
velocity profiles when comparing the modified flare tip including
the internal spin vanes to a flare tip without spin vanes (not
shown). Additionally, the burn profiles shown in FIGS. 5A-5F show
improved mixing between the waste gas (propane gas) and the
surrounding atmosphere.
Example 2
[0031] A similar CFD study to that discussed in Example 1 was
conducted using a modified flare tip including five-inch wide
internal spin vanes and a twenty-four inch velocity seal. The
operating parameters utilized to conduct the study are provided
below in Table 2.
TABLE-US-00002 TABLE 2 Parameter Propane Flow 60,000 lbs/hr Propane
Temp 100.degree. F. Air Flow 100,000 ACFM Air Temp 100.degree. F.
Wind Speed/Direction 10 ft/sec left-right
[0032] FIGS. 6A-6D show the burn profiles of a combustion gas
stream using the modified flare tip including a twenty-four inch
velocity seal. FIGS. 6A-56B show the air volume fraction within the
gas stream, and FIGS. 6C-6D show the volume fraction of propane
within the combustion gas stream. FIGS. 6E-6H show the velocity
contours within the gas stream produced using the modified flare
tip including a twenty-four inch velocity seal.
[0033] Again, the burn profiles and velocity profiles shown in
FIGS. 6A-6H show improved mixing between the waste gas (propane
gas) and the surrounding atmosphere.
[0034] As a result of the CFD studies, it is believed that by
providing internal spin vanes within the flare tip, the velocity
profile within the flare tip is improved, improving mixing between
the waste gas and the surrounding atmosphere.
[0035] The disclosure should not be considered limited to the
particular examples described above. Various modifications,
equivalent processes, as well as numerous structures to which the
disclosure can be applicable will be readily apparent to those of
skill in the art upon review of the instant specification. Other
steps may be provided, or steps may be eliminated, from the
described methods, and other components may be added to, or removed
from, the described devices. Also, in the present specification,
some of the matter may be of a hypothetical or prophetic nature
although stated in another manner or tense.
* * * * *