U.S. patent application number 12/957266 was filed with the patent office on 2012-05-31 for moisture removal for gasification quench chamber assembly.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. Invention is credited to Judeth Brannon Corry, Gregory Michael Laskowski, Prashant Tiwari.
Application Number | 20120131852 12/957266 |
Document ID | / |
Family ID | 46125694 |
Filed Date | 2012-05-31 |
United States Patent
Application |
20120131852 |
Kind Code |
A1 |
Tiwari; Prashant ; et
al. |
May 31, 2012 |
MOISTURE REMOVAL FOR GASIFICATION QUENCH CHAMBER ASSEMBLY
Abstract
A gasification assembly that includes a quench chamber and
downstream transfer piping is disclosed. The gasification assembly
includes the quench chamber and a liquid coolant disposed therein,
and a dip tube that is configured to couple a combustion chamber to
the quench chamber and also configured to direct syngas from the
combustion chamber to the liquid coolant and produce a cooled
syngas. The assembly further includes a transfer pipe that is in
fluid communication with the cooled syngas and configured to
transfer the cooled syngas to a downstream scrubber component. The
transfer pipe further includes an excess moisture removal device,
which is configured to remove moisture from the cooled syngas.
Inventors: |
Tiwari; Prashant; (Clifton
Park, NY) ; Corry; Judeth Brannon; (Manvel, TX)
; Laskowski; Gregory Michael; (Saratoga Springs,
NY) |
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
46125694 |
Appl. No.: |
12/957266 |
Filed: |
November 30, 2010 |
Current U.S.
Class: |
48/87 |
Current CPC
Class: |
C10J 3/526 20130101;
C10J 3/84 20130101; C10K 1/00 20130101; B01D 45/16 20130101; C10J
2300/1807 20130101 |
Class at
Publication: |
48/87 |
International
Class: |
C10J 3/72 20060101
C10J003/72 |
Claims
1. A gasification assembly comprising: a quench chamber having a
liquid coolant disposed therein; a dip tube configured to couple a
combustion chamber to the quench chamber and configured to direct
syngas from the combustion chamber to the liquid coolant and
produce a cooled syngas; and a transfer pipe in fluid communication
with the cooled syngas, configured to transfer the cooled syngas to
a downstream scrubber component, wherein the transfer pipe further
comprises an excess moisture removal device, configured to remove
moisture from the cooled syngas.
2. The gasification assembly of claim 1, wherein the excess
moisture removal device is configured to employ centrifugal action
to remove moisture from the cooled syngas.
3. The gasification assembly of claim 2, wherein the excess
moisture removal device comprises a baffle.
4. The gasification assembly of claim 1, further comprising a
return line in fluid communication between the moisture removal
device and the quench chamber configured to return a portion of the
removed moisture to the liquid coolant.
5. The gasification assembly of claim 1, wherein the excess
moisture removal device injects a fluid at the exiting syngas,
wherein the fluid has a higher temperature than the exiting syngas,
thereby evaporating a portion of the moisture.
6. The gasification assembly of claim 5, wherein the fluid is a hot
syngas.
7. The gasification assembly of claim 6, wherein the fluid is
provided from a gas turbine.
8. The gasification assembly of claim 1, wherein the excess
moisture removal device comprises a plurality of perforations
configured to allow egress of the removed moisture from the
transfer pipe.
9. The gasification assembly of claim 8, further comprising a
return line in fluid communication between the plurality of
perforations and the quench chamber configured to return a portion
of the removed moisture to the liquid coolant.
10. The gasification assembly of claim 8, wherein the plurality of
perforations are in fluid communication with a reservoir.
11. The gasification assembly of claim 8, further comprising a
cooling device in fluid communication with one of the transfer pipe
and the excess moisture removal device, configured to condense
moisture from the cooled syngas.
12. The gasification assembly of claim 11, wherein the cooling
device comprises a sleeve partially surrounding a portion of the
transfer pipe, further wherein the sleeve has a fluid therein
having a temperature less than a temperature of the cooled syngas
in the transfer pipe.
Description
BACKGROUND
[0001] The invention relates generally to gasifiers, and more
particularly to moisture removal at or near the exit of a quench
chamber.
[0002] In a normal coal gasification process, wherein a
particulated carbonaceous fuel such as coal or coke or a
carbonaceous gas is burned, the process is carried out at
relatively hot temperatures and high pressures in a combustion
chamber. When injected fuel is burned or partially burned in the
combustion chamber, an effluent is discharged through a port at a
lower end of the combustion chamber to a quench chamber disposed
downstream of the combustion chamber. The quench chamber contains a
liquid coolant such as water. The effluent from the combustion
chamber is contacted with the liquid coolant in the quench chamber;
so as to reduce the temperature of the effluent.
[0003] When the fuel is a solid such as coal or coke, the gasifier
arrangement permits a solid portion of the effluent, in the form of
ash, to be retained in the liquid pool of the quench chamber, and
subsequently to be discharged as slag slurry. A gaseous component
of the effluent is discharged from the quench chamber for further
processing. The gaseous component, however, in passing through the
quench chamber, will carry with it a substantial amount of the
liquid coolant. A minimal amount of liquid entrained in the exiting
gas is not considered objectionable to the overall process.
However, excessive liquid carried from the quench chamber and into
downstream equipment, is found to pose operational problems.
[0004] In conventional systems, a baffle is placed in the gas
exiting path in the quench chamber. Consequently, as
liquid-carrying gas contacts the baffle surfaces, a certain amount
of the liquid will coalesce on the baffle surfaces. However, the
rapidly flowing gas will re-entrain liquid droplets by sweeping
droplets from the baffle's lower edge.
[0005] There is a need for an improved quench chamber assembly
configured to more effectively remove entrained liquid content
substantially from the effluent gas.
BRIEF DESCRIPTION
[0006] In accordance with one exemplary embodiment of the present
invention, a gasification assembly comprises a quench chamber
having a liquid coolant disposed therein; a dip tube configured to
couple a combustion chamber to the quench chamber and configured to
direct syngas from the combustion chamber to the liquid coolant and
produce a cooled syngas; and a transfer pipe in fluid communication
with the cooled syngas, configured to transfer the cooled syngas to
a downstream scrubber component, wherein the transfer pipe further
comprises an excess moisture removal device, configured to remove
moisture from the cooled syngas.
DRAWINGS
[0007] These and other features, aspects, and advantages of the
present invention will become better understood when the following
detailed description is read with reference to the accompanying
drawings in which like characters represent like parts throughout
the drawings, wherein:
[0008] FIG. 1 depicts a sectional elevation view of a gasification
quench chamber assembly in accordance with an exemplary embodiment
of the present invention;
[0009] FIG. 2 depicts a close-up sectional elevation view of a
transfer pipe portion of a gasification quench chamber assembly in
accordance with an exemplary embodiment of the present
invention;
[0010] FIG. 3 depicts a top sectional view of the transfer pipe
portion of a gasification quench chamber assembly in FIG. 2 in
accordance with an exemplary embodiment of the present
invention;
[0011] FIG. 4 depicts a close-up sectional elevation view of a
transfer pipe portion of a gasification quench chamber assembly in
accordance with an exemplary embodiment of the present
invention;
[0012] FIG. 5 depicts an end sectional view of the transfer pipe
portion of a gasification quench chamber assembly in FIG. 4 in
accordance with an exemplary embodiment of the present
invention;
[0013] FIG. 6 depicts a sectional elevation view of a transfer pipe
portion of a gasification quench chamber assembly in accordance
with an exemplary embodiment of the present invention; and
[0014] FIG. 7 depicts a sectional elevation view of a gasification
quench chamber assembly in accordance with another exemplary
embodiment of the present invention.
DETAILED DESCRIPTION
[0015] In accordance with the exemplary embodiments disclosed
herein, a gasifier having a quench chamber assembly configured to
reduce temperature of syngas downstream of a gasification chamber
is disclosed. The gasifier includes a quench chamber containing a
liquid coolant disposed downstream of the gasification chamber. A
syngas generated from the gasification chamber is directed via a
dip tube to the quench chamber to contact the liquid coolant and
produce a cooled syngas. A baffle is disposed proximate to an exit
path of the quench chamber. In some embodiments, a draft tube may
be disposed surrounding the dip tube such that an annular passage
is formed between the draft tube and the dip tube. The cooled
syngas is directed through the annular passage (if present) and
impacted against the baffle so as to remove entrained liquid
content from the cooled syngas before the cooled syngas is directed
through the exit path. In some embodiments, a deflector plate is
disposed between the liquid coolant and the exit path of the quench
chamber and configured to remove entrained liquid content from the
cooled syngas and prevent sloshing of liquid content to the exit
path. In some embodiments, the baffle is asymmetric or symmetric,
either open or angular, to remove entrained liquid content from the
cooled syngas. In other embodiments, the baffle itself can have
channels or cut-outs and overlays to remove entrained liquid and
prevent sloshing of liquid content to the exit path. In other
embodiments only dip tube is present and the annular section is
formed between the dip tube and the quench chamber wall. The
provision of asymmetric or symmetric shaped baffle, deflector
plate, swirl generator, or combinations thereof substantially
reduces entrainment of liquid content in the syngas directed
through the exit path to the downstream components (e.g., scrubber
assembly, etc.). An entrainment mitigation mechanism, or moisture
removal device, is provided at, or along, the transfer pipe exiting
the quench chamber. Specific embodiments are discussed in greater
detail below with reference to FIGS. 1-7.
[0016] Aspects of the present invention relate to a gasification
component, namely, a gasification quench chamber assembly, which
includes the quench chamber, proper, and other appurtenances such
as the quench chamber exit pipe, or transfer line. Quench is
typically presented downstream of the gasification chamber and used
to reduce the temperature of the manufactured syngas as well as
remove (at least partially) solids/fines. In some embodiments,
there may be a radiant syngas cooler located intermediate the
gasification chamber and the quench chamber. As is typical, the
syngas is introduced into the quench chamber via a dip tube. The
quench chamber contains a liquid coolant, which reduces the
temperature of the syngas. After quenching, the syngas rises up,
due to buoyancy. Other features found in quench chambers include an
entrainment baffle(s), or splash plate(s), present near the exit of
the dip tub. The purpose of the entrainment baffle(s) is ostensibly
to knock off water droplets, which are entrained with the outgoing
syngas. As the entrainment baffle(s) is not 100% efficient in
removal of the liquid from the syngas, liquid is still present in
the syngas exiting the quench chamber via the exit pipe. The amount
of fines and liquid entrainment in the outgoing syngas also poses a
significant challenge in the instrumentation and/or measuring the
amount of liquid getting entrained in the quench chamber exit
pipe.
[0017] Aspects of the present invention increase the overall
effectiveness and efficiency of the gasification system by
improving upon the removal of entrained liquid from the generated
syngas. Further aspects of the present invention address improved
removal of entrained liquid while reducing manufacturing costs
and/or operating expenses. Aspects of the present invention offer a
simplified design, which additionally improve the life of the
assembly and reliability, availability, and maintenance of the
gasification plant.
[0018] The entrainment mitigation mechanisms depicted in FIGS. 1-7
may be employed separately or in combination with one another.
Moreover, as may be appreciated, the relative sizes, shapes, and
geometries of the entrainment mitigation mechanisms may vary. The
entrainment mitigation mechanisms may be employed along with a
quench chamber during the initial manufacturing, or the entrainment
mitigation mechanisms may be retrofit to existing quench units.
Further, the entrainment mitigation mechanisms may be adjusted
based on operational parameters, such as the type of carbonaceous
fuel, the system efficiency, the system load, or environmental
conditions, among others to achieve the desired amount of flow
damping.
[0019] Referring to FIG. 1 depicts an exemplary embodiment of
portions of a gasification system in accordance with aspects of the
present invention. As shown, a gasification quench chamber
assembly, or gasification assembly, 800 comprises a quench chamber
802 and a transfer pipe 870. The quench chamber 802 is in fluid
communication with a gasification chamber 900, upstream, and quench
chamber 802 is in fluid communication with a scrubber assembly 920,
downstream, via the transfer pipe 870. In embodiments, the transfer
pipe 870 may be additionally in fluid communication with the quench
chamber 802 via a return tube 874. Similarly, in another
embodiment, the transfer pipe 870 may additionally be in fluid
communication with a heat source 910 (e.g., gas turbine, etc.) via
a supply line 878 as shown in FIG. 7.
[0020] The quench chamber 802 comprises a dip tube 806 which is
configured to couple the gasification chamber 900 to the quench
chamber 802 and is further configured to direct syngas 1000 from
the combustion chamber 900 to a liquid coolant 804 contained in a
portion of the quench chamber 802. The quench chamber 802 may
further include an inlet line 805 for providing any requisite
liquid coolant 804 to the quench chamber 804. By introducing the
syngas 1000 to the liquid coolant 804, the syngas 1000 is cooled
and exits the quench chamber as cooled syngas 1002 via the transfer
pipe 870 towards the scrubber assembly 920. Upon the cooling of the
syngas 1000 in the quench chamber 802, slag or fines 810, may
precipitate out of the syngas 1000 thereby settling at the bottom
of the quench chamber 804. The quench chamber 804 may further
comprise at least one baffle 808 that aids in knocking out and/or
off water droplets entrained in the exiting syngas 1002.
[0021] It should be noted that various configurations of quench
chamber could be employed without departing from aspects of the
present invention. For example, although FIGS. 1 and 7 depict a
quench chamber 802 having a dip tube-only configuration, the quench
chamber 802 may alternatively employ a dip/draft configuration, a
dip only configuration, a dip/draft with a quench ring
configuration, and the like.
[0022] The transfer pipe 870 is configured to provide a means for
transmitting the cooled syngas 1002 to the scrubber assembly 920
and other downstream components (not shown). The transfer pipe, or
line, 870 further comprises an excess liquid removal device, or
entrainment mitigation mechanism, 872 that is configured to further
remove excess liquid (e.g., water, etc.) from the cooled syngas
1002 so that a cooled syngas 1006, with an even smaller amount of
liquid, ultimately is conveyed to the downstream scrubber assembly
920 and other downstream components.
[0023] As shown in FIG. 1, the excess liquid removal device 872
employed by aspects of the present invention include one or more of
applying a centrifugal action or force to remove excess liquid from
the cooled syngas 1002; and/or perforating at least a portion of
the transfer pipe 870 to provide an egress means for excess liquid
(e.g., water droplets) in the cooled syngas 1002. In any event,
excess liquid is effectively removed from the syngas prior to it
reaching the scrubber assembly 920, resulting in an improved
gasification process.
[0024] In an embodiment a water injection line may also be
provided, as denoted by 950 and 960. In this manner, water may be
added along the line 870 in one or more locations. For example, as
shown, the injection line may be located anterior to the 876 as
denoted by 950. The injection line may be located within the
moisture removal device 870. The water injection line may be
located in either of these locations, or both locations, as well as
any location along the transfer line 870.
[0025] Referring to FIGS. 2 and 3, an excess liquid removing device
872 that employs perforations is shown. The transfer line 870
includes an excess liquid removing device 872 that comprises a
plurality of perforations 880 configured to allow egress of
moisture from the transfer pipe 870. To aid in the removal of
moisture from the syngas 1004 a sleeve 889, such as a cold-water
sleeve, may be provided, wherein the sleeve 889 partially or
substantially surrounds a portion of the transfer pipe 870. The
sleeve 889 may contain a cooling fluid (e.g., water) therein that
has a temperature that is less than a temperature of the cooled
syngas 1004 within the transfer pipe 870. In this manner, the
sleeve 889 aids in further condensing moisture in the travelling
syngas 1004 so that the moisture may drop or settle out via the
plurality of perforations 880 and be collected via collection pipe
882 and returned via return line 874 back to the quench chamber 802
(FIG. 1).
[0026] Clearly other configurations than those depicted in FIGS. 2
and 3 may be provided without departing from aspects of the present
invention. By way of example, and without limitation, other
configurations of perforations may be provided. For example, the
perforations may have different quantities, shapes, configurations,
patterns, and the like, from those shown. Similarly, the sleeve may
surround the transfer line 870 in a different manner. For example,
the sleeve may fully or partially surround the transfer line 870.
Similarly, the cooling fluid used in the cooling sleeve may be any
suitable fluid that assists in condensing moisture out of the
syngas 1004.
[0027] Referring to FIGS. 4 and 5, an excess liquid removing device
872 that employs centrifugal force or action is shown. The transfer
line 870 includes an excess liquid removing device 872 that
comprises a baffle 876 or similar means for exerting or employing
centrifugal force to the syngas 1004. The baffle 876 may, for
example, include one or blades or vanes that are curved or warped
in relationship to the direction of travel of the syngas 1004
through the transfer line 870 (See e.g., FIG. 5). In consort with
the baffle 876, a plurality of perforations 880 may be located on a
wall of the transfer line 870 thereby providing an egress means for
the moisture (e.g., water droplets) that is spun or forced towards
the periphery of the transfer line 870 by the centrifugal force
caused by the baffle 876. As shown, a return line 874 may be used
to return any collected moisture from the perforations. The return
line 874 maybe in fluid communication with the quench chamber 802
(FIG. 1).
[0028] Referring to FIG. 6, a cross section elevation view of
another embodiment of a excess liquid removing device 2000 is
depicted. The moisture removal device 2000 may comprise a pipe 2012
having one or more tees 2010 (e.g., two tees shown in embodiment in
FIG. 6) extending therefrom. The pipe 2012 conveys outgoing syngas
3000 from a quench chamber 802 (FIG. 1) towards a scrubber assembly
920 (FIG. 1). The one or more tees 2010 along the pipe 2012 provide
a fluid communication connection with an entrainment vessel 2020.
Alternatively to having tees 2010 there may be one or more
perforations, openings, and the like, that allow excess moisture to
escape from the syngas that is travelling along the pipe 2012. In
any event, the entrainment vessel 2020 gathers moisture 3030
therein and may have a controlled water level. The moisture 3030
may be continually flushed back to the quench chamber 802 by a
water flow 3015 that is provided into the entrainment vessel 2020
via an input line 2030. The flushing back to the quench chamber 802
via return line 2035 may be continual or periodic so as to prevent
plugging. The entrainment vessel 2020 may be designed so that any
transient excess water flow (i.e., liquid entrainment) may flow
back, as denoted by 3020, to the quench chamber 802 while
maintaining an appropriate pressure drop. The return line 2035 may
include a raised loop 2025 having a height, denoted by D, above the
water level of the entrainment vessel 2020. The height, D, may be
adjustable as required by the particular application in use. In
this manner, excess moisture removed from the syngas may be readily
removed and returned to the quench chamber 802 for reuse.
[0029] Referring to FIG. 7, the excess liquid removal device 872 in
another embodiment of the present invention includes any
combination of: applying a centrifugal action or force to remove
excess liquid from the cooled syngas 1002; and/or, perforating at
least a portion of the transfer pipe 870 to provide an egress means
for excess liquid (e.g., water droplets) in the cooled syngas 1002;
and/or, heating the exiting cooled syngas 1002 so as to evaporate
out moisture droplets held in the exiting cooled syngas 1002. In
any event, excess liquid is effectively removed from the syngas
prior to it reaching the scrubber assembly 920, resulting in an
improved gasification process.
[0030] The centrifugal action or force and perforation embodiments
are discussed above, in reference to FIG. 1. As shown in FIG. 7,
under another aspect of the present invention the excess liquid
removing device 872 may use evaporation or evaporative means to
remove moisture from the syngas 1002. The evaporative means may
comprise injecting a fluid 912 at the existing syngas 1004, wherein
the fluid 912 has a higher temperature than the temperature of the
exiting syngas 1002, thereby aiding in evaporating at least a
portion of the remaining moisture in the existing syngas 1002. In
this manner, additional moisture is removed from the existing
syngas 1002. As shown, the fluid 912 may comprise injecting, via an
injection line 878, a hot syngas provided from a heat source 910 or
the like. In an embodiment, the supplied hot syngas 912 is supplied
from a heat source 910 that may be a gas turbine, a syngas cooler,
a gasifier, and the like.
[0031] In accordance with one exemplary embodiment of the present
invention, a gasification assembly comprises a quench chamber
having a liquid coolant disposed therein; a dip tube configured to
couple a combustion chamber to the quench chamber and configured to
direct syngas from the combustion chamber to the liquid coolant and
produce a cooled syngas; and a transfer pipe in fluid communication
with the cooled syngas, configured to transfer the cooled syngas to
a downstream scrubber component, wherein the transfer pipe further
comprises an excess moisture removal device, configured to remove
moisture from the cooled syngas.
[0032] This written description uses examples to disclose the
invention, including the best mode, and also to enable any person
skilled in the art to practice the invention, including making and
using any devices or systems and performing any incorporated
methods. The patentable scope of the invention is defined by the
claims, and may include other examples that occur to those skilled
in the art. Such other examples are intended to be within the scope
of the claims if they have structural elements that do not differ
from the literal language of the claims, or if they include
equivalent structural elements with insubstantial differences from
the literal languages of the claims.
[0033] While only certain features of the invention have been
illustrated and described herein, many modifications and changes
will occur to those skilled in the art. It is, therefore, to be
understood that the appended claims are intended to cover all such
modifications and changes as fall within the true spirit of the
invention.
* * * * *