U.S. patent application number 09/987154 was filed with the patent office on 2003-03-27 for device for incinerating waste gas.
Invention is credited to Coffey, Clayton G., Markov, Alexander B..
Application Number | 20030059732 09/987154 |
Document ID | / |
Family ID | 25504950 |
Filed Date | 2003-03-27 |
United States Patent
Application |
20030059732 |
Kind Code |
A1 |
Coffey, Clayton G. ; et
al. |
March 27, 2003 |
Device for incinerating waste gas
Abstract
A device for incinerating waste gases has a combustion chamber,
burner for burning waste gas in the combustion chamber, and a
tubular conduit extending substantially vertically from the
combustion chamber so that products of combustion of the waste gas
in the combustion chamber travel vertically upwardly through the
tubular conduit, the tubular conduit being composed of a plurality
of tubular elements located one above the other and arranged
relative to one another so as to form a gap between each two
neighboring tubular elements for introducing air into an interior
of the tubular conduit through the gaps.
Inventors: |
Coffey, Clayton G.;
(Medicine Hat, CA) ; Markov, Alexander B.;
(Medicine Hat, CA) |
Correspondence
Address: |
ROSEANN B. CALDWELL
BENNETT JONES LLP
4500, 855 2nd Street S.W.
Calgary, Alberta
T2P 4K7
CA
|
Family ID: |
25504950 |
Appl. No.: |
09/987154 |
Filed: |
November 13, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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09987154 |
Nov 13, 2001 |
|
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09961757 |
Sep 25, 2001 |
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Current U.S.
Class: |
431/352 ;
431/202; 431/5 |
Current CPC
Class: |
F23G 7/08 20130101 |
Class at
Publication: |
431/352 ; 431/5;
431/202 |
International
Class: |
F23D 001/00; F23D
014/00 |
Claims
1. A device for incinerating waste gas, comprising a combustion
chamber; means for burning waste gas in said combustion chamber;
and a tubular conduit extending substantially vertically from said
combustion chamber so that products of combustion of the waste gas
in said combustion chamber travel vertically upwardly into said
tubular conduit, said tubular conduit being composed of a plurality
of tubular elements located one above the other and arranged
relative to one another so as to form a gap between each two
neighboring tubular elements for introducing air into the interior
of said tubular conduit through said gaps.
2. A device as defined in claim 1, wherein said tubular elements
have different diameters such that a tubular element with a greater
diameter is located above a tubular element with a smaller diameter
to form said gap therebetween.
3. A device as defined in claim 1, wherein said tubular elements
have a cross section other than circular.
4. A device as defined 1, wherein said tubular elements of said
tubular conduits are formed so that said gaps are open outside so
that the air is aspirated through said gaps from outside inwardly
into each of said tubular elements.
5. A device as defined in claim 1, wherein the number, size and
position of said gaps are chosen so that the wall temperature of
the tubular elements does not exceed a specified value.
6. A device as defined in claim 1, wherein the number, size and
position of said gaps are chosen so as to provide the maximize
possible dilution of the combustion products before said products
exit said tubular conduit.
7. A device as defined in claim 1, wherein the number, size and
position of said gaps are chosen so as to ensure the combustion
products exceed a specified temperature for a specified duration
before said products exit said tubular conduit.
8. A device as defined in claim 1; and further comprising means for
forced supply of air through said gaps between said tubular
elements.
9. A device as defined in claim 1, wherein an additional tubular
enclosure is arranged around said tubular conduit so that air is
supplied first in a space between said tubular element and said
tubular enclosure and then travels through said gaps into an
interior of said tubular conduit.
10. A device as defined in claim 1 wherein each of said gaps is
subdivided in a circumferential direction by a plurality of
partitions which form a plurality of slots and also serve for
connecting said tubular elements with one another.
11. A device as defined in claim 1, wherein the partitions of one
gap are circumferentially offset relative to the partitions of the
other gap.
12. A ground flare stack for incinerating waste gases, the stack
having a lower tubular portion and an upper tubular exhaust
portion, comprising: (a) a tubular burn chamber located
intermediate the lower and upper portions and having combustion air
intakes located below the burn chamber, (b) one or more pairs of
waste gas inlet ports and closure ports, the inlet and closure port
of each pair being located on opposing sides of the burn chamber,
(c) a service access port located in the stack at an elevation
equal to or below the waste gas inlet ports; (d) one or more
primary burner assemblies fitted within the burn chamber between
the inlet and closure ports, the burner assemblies accepting waste
gases from the inlet port and discharging waste gases into the burn
chamber for mixing with the combustion air for creating exhaust
gases; and (e) the tubular exhaust stack having one or more axially
displaced tubular exhaust shells, each upwardly adjacent exhaust
shell having a greater diameter than the preceding exhaust shell,
the exhaust shells forming a contiguous bore and being
concentrically spaced for forming one or more annular inlets for
admitting additional annular air into the stack for discharge with
the exhaust gases.
13. The ground flare stack as recited in claim 12 wherein the
annular inlets admit sufficient additional annular air for improved
dispersion of the exhaust gases into the atmosphere.
14. The ground flare stack as recited in claim 12 further
comprising one or more auxiliary burners fitted within the tubular
exhaust stack above at least one of the one or more annular inlets,
the annular inlets admitting additional annular air as primary
combustion air for the one or more auxiliary burners to the
stack.
15. The ground flare stack as recited in claim 13 wherein each
axially displaced tubular exhaust shell has a lower edge at the
annular inlet which is fitted with a bell-mouth intake so as to
result in an improved intake of additional annular air.
16. The ground flare stack as recited in claim 15 wherein the bell
mouth intake comprises a hoop of a circular cross-section.
17. The ground flare stack as recited in claim 16 wherein the two
or more auxiliary burners are fed waste gas from a header.
18. The ground flare stack as recited in claim 17 wherein hoop is
tubular and has a bore so that the hoop's bore forms the header.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 09/961,757, filed Sep. 25, 2001 (with the same title, filed by
Ely Y. Zborovsky, Registered Patent Agent No. 28,563), the entire
disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to devices for incineration of
waste gases.
[0003] There is a frequent need in the oil and gas industry to
dispose of flammable gases. This is usually necessary because small
quantities of gas are either not economical to process or are toxic
and must be neutralized. The most common means for eliminating
these gases is to burn them in the atmosphere using a flare stack.
This device typically is formed as a tall pole with an open
diffusion flame anchored at the top. The orange color of the flame
and the intermittent presence of black soot are evidence that the
combustion process is not particularly efficient with this type of
apparatus. The efficiency can be further adversely affected by the
presence of ambient winds. Some parts of a diffusion flame are
relatively cool and the residency time of the combustibles in the
flame can be quite short. Under some conditions, certain chemical
species may not undergo complete thermal decomposition and
oxidation. This can lead to the release of toxic substances, for
example hydrogen sulphide, into the atmosphere. The results are
obnoxious odors and an unsightly flame, both of which have become
the targets of environmental groups and government regulatory
agencies.
[0004] It is known that efficient burners are used in industrial
incinerators. However, the combustion chamber in these devices is
typically lined with a glass or ceramic refractory liner in order
to protect the chamber walls from the high temperature corrosive
gases. Some methods of minimizing the heat transfer from hot
exhaust gases to the surrounding duct walls for the purpose of
minimizing the emitted infrared radiation from a war ship are
proposed in U.S. Pat. No. 4,355,507 and Canadian patent no.
1,134,827. These methods employ the well known phenomenon of film
cooling.
[0005] It is believed that improvements in waste gas incinerating
devices are both desirable and achievable via the appropriate
application of similar film cooling techniques.
SUMMARY OF THE INVENTION
[0006] Accordingly, it is an object of present invention to provide
a device for incinerating waste gases, which avoids the
disadvantages of the prior art. In keeping with these objects and
with others which will become apparent hereinafter, one feature of
present invention resides, briefly stated, in a device for
incinerating waste gases, comprising a combustion chamber; means
for burning waste gas in said combustion chamber; and a tubular
conduit extending substantially vertically from said 110 combustion
chamber so that products of combustion of the waste gas in said
combustion chamber travel vertically upwardly through said tubular
conduit, said tubular conduit being composed of a plurality of
tubular elements located one above the other and arranged relative
to one another so as to form a gap between each two neighboring
tubular elements for introducing air into the interior of said
tubular conduit through said gaps.
[0007] In accordance with another feature of the present invention,
the tubular elements have different diameters such that a tubular
element with a greater diameter is located above a tubular element
with a smaller diameter to form the gap therebetween.
[0008] In accordance with another feature of present invention, the
tubular elements of the tubular conduit are formed so that the gaps
are open outwardly so that the air can be introduced through the
gaps from outside inwardly into each of the tubular elements.
[0009] In accordance with still a further feature of present
invention, means is provided for the forced supply of air through
the gaps between said tubular elements.
[0010] In accordance with still a further feature of present
invention, an additional tubular enclosure is arranged around the
tubular conduit so that air is supplied first in a space between
the tubular conduit and the tubular enclosure and then travels
through the gaps into the interior of the tubular conduit.
[0011] In accordance with still another feature of present
invention, each of the gaps is sub divided in a circumferential
direction by a plurality of partitions which serve to connect the
tubular elements with one another and also to straighten the flow
of air entering the gaps.
[0012] In accordance with still a further feature of the present
invention, the partitions of one gap are circumferentially offset
relative to the partitions of the other gap to form offset slots
therebetween.
[0013] The novel features which are considered as characteristic
for the present invention are set forth in particular in the
appended claims. The invention itself, however, both as to its
construction and its method of operation, together with additional
objects and advantages thereof, will be best understood from the
following description of specific embodiments when read in
connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a view schematically showing a device for
incinerating waste gas;
[0015] FIGS. 2 and 3 are views showing two modifications of the
inventive device for incinerating waste gas; and
[0016] FIG. 4 is a plan view of the inventive device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] A device for incinerating waste gases shown in FIG. 1 has a
combustion chamber which is identified as a whole with reference
numeral 1. It can be provided with a plurality of burners which are
identified with reference numeral 2 and can be formed from known
commercial burners which are used for burning gases. A number and
location of the burners 2 in the combustion chamber 1 is selected
in accordance with the type and volume of waste gas to be
incinerated and other related parameters.
[0018] The device for incinerating waste gases is further provided
with a tubular conduit which is identified as a whole with
reference numeral 3. The tubular conduit 3 extends vertically
upwardly from the combustion chamber 1. It is to be understood that
the combustion chamber 1 is open into the interior of the tubular
element 3. For example a grate 4 can be arranged between the
combustion chamber 1 and the tubular conduit 3 to permit the
products of combustion of the waste gas to flow vertically upwardly
from the combustion chamber 1 into the tubular conduit 3.
[0019] In accordance with the present invention, the tubular
conduit is composed of a plurality of tubular elements 5. The
tubular elements 5 are shown as cylindrical tubular elements.
However, of course, they can also have another cross-section, while
then only being necessary to comply with the main requirement to
have a peripherally closed wall. In accordance with the present
invention, the tubular elements 5 have different diameters. In
particular the diameters of the tubular elements increase
vertically upwardly, so that the tubular element with a smaller
diameter is located lower, and the tubular element with the greater
diameter is located higher, correspondingly. The tubular elements 5
are arranged relative to one another so that a gap 6 is formed
between two neighboring tubular elements. The combustion chamber 1
is provided with an auto ignitor 7 which is known in the art.
[0020] While FIG. 1 shows a general schematic view of the inventive
device for incinerating waste gases, FIGS. 2 and 3 show further
different embodiments of the inventive device. FIG. 2 shows the
device for incinerating waste gases in accordance with the present
invention, which is preferably used in a field remote from urban
areas. As can be seen from FIG. 2 the gaps 6 between the tubular
elements 5 are retained open to the outside. During the operation
of the device shown in FIG. 2, the waste gas is burned by the
burners 2 in the combustion chamber 1 and the products of
combustion flow upwardly into the tubular conduit 3. During upward
movement of the products of combustion, air is aspirated through
the gaps between the tubular elements 5 as a consequence of the low
static pressure that exists inside the tubular conduit 3. each
tubular element is fitted along its lowermost edge with a
peripherally oriented external tube 5' that promotes structural
rigidity of the tubular element and also provides a well rounded
inlet for the air entering gap 6
[0021] The tubular conduit 3 protects the combustion process from
ambient winds. It also removes the combustion process from public
view. The entrained ambient air both protects the inner walls of
the tubular conduit from the hot corrosive gases and also convects
away the heat radiated from the hot gases to the inner walls, and
thereby it is not necessary to provide a refractory liner as in
known devices. Entrained ambient air also ensures well-ventilated
and efficient combustion. Also, the resulting combustion products
are diluted by ambient air before they exit the device. This aspect
of the invention, in conjunction with the fact that the gases
inside the conduit achieve significant vertical velocity, results
in lower ground-level concentrations of combustion products than
for an equivalent conventional flare stack. This is important from
both a regulatory point of view and from the standpoint of
minimizing odours. The device shown in FIG. 2, because of its open
slots 6. of course produces some noise, and therefore, it is not
recommended to be used in urban areas.
[0022] In contrast, the device shown in FIG. 3 is recommended for
urban areas. The device shown in FIG. 3 substantially corresponds
to the device shown in FIG. 2, but in addition it has means for
forced supply of air which is identified with reference 8. The
means for forced supply of air can be formed for example as a
centrifugal air blower. Additionally a tubular enclosure 9 is
provided which surrounds the tubular conduit 3 so as to form a
peripheral space therebetween.
[0023] During the operation of the device shown in FIG. 3, air is
forcedly supplied by the centrifugal blower 8 into a space between
the tubular enclosure 9 and the tubular conduit 3, and then air
flows through the gaps 6 into the interior of the corresponding
tubular elements 5 of the tubular conduit 3, with the results which
were previously explained herein in connection with the device
shown in FIG. 2. Since the device is provided with the enclosure 9
it does not generate excessive noise and, therefore, can be used in
urban areas.
[0024] FIG. 4 shows the structure of the gaps 6 between the tubular
elements 5. As can be seen from this drawing, each gap is
subdivided into a plurality of slots which adjoin one another in a
peripheral direction. The subdivision of the gap 6 into slots 10 is
performed by partitions 11. The partitions 11, in addition to the
subdivision of the gaps 6 into the slots 10, serve for connection
of the two adjoining tubular elements 5 with one another. They are
preferably formed as connecting ribs. These partitions reduce the
adverse effect of cross winds on the flow entering the gaps 6.
[0025] As can be also seen from FIG. 4, the slots 10 of different
gaps 6 are offset relative to one another in a peripheral
direction. This provides a more efficient distribution of air
supply into the interior of the tubular conduit 3.
[0026] Complete thermal decomposition and oxidation of noxious
substances require that the combustible be maintained above a
threshold temperature for a minimum duration. The required
temperature and duration depend on the substances being burned.
With the present invention it is possible to control the
temperature history and residency time of the substances being
combusted by an appropriate selection of the size and position of
the entraining slots 10 relative to one another, and the overall
heights of the conduit 3.
[0027] It will be understood that each of the elements described
above, or two or more together, may also find a useful application
in other types of constructions differing from the types described
above.
[0028] While the invention has been illustrated and described as
embodied in device for incinerating waste gas, it is not intended
to be limited to the details shown, since various modifications and
structural changes may be made without departing in any way from
the spirit of the present invention.
[0029] Without further analysis, the foregoing will so fully reveal
the gist of the present invention that others can, by applying
current knowledge, readily adapt it for various applications
without omitting features that, from the standpoint of prior art,
fairly constitute essential characteristics of the generic or
specific aspects of this invention.
[0030] What is claimed as new and desired to be protected by
Letters Patent is set forth in the appended claims:
* * * * *