U.S. patent application number 15/338574 was filed with the patent office on 2018-05-03 for system and method for removing ash deposits within a boiler.
This patent application is currently assigned to GENERAL ELECTRIC TECHNOLOGY GMBH. The applicant listed for this patent is GENERAL ELECTRIC TECHNOLOGY GMBH. Invention is credited to AQIL JAMAL, ARMAND LEVASSEUR, TIDJANI NIASS, OLAF STALLMANN, MOURAD YOUNES, WEI ZHANG.
Application Number | 20180119952 15/338574 |
Document ID | / |
Family ID | 60268350 |
Filed Date | 2018-05-03 |
United States Patent
Application |
20180119952 |
Kind Code |
A1 |
LEVASSEUR; ARMAND ; et
al. |
May 3, 2018 |
SYSTEM AND METHOD FOR REMOVING ASH DEPOSITS WITHIN A BOILER
Abstract
A system for removing ash deposits within a boiler is provided.
The system includes a soot blower disposed within the boiler, and a
gas supply line in fluid communication with the soot blower and a
gas source. The soot blower is operative to inject compressed gas
from the gas source into the boiler to remove the ash deposits from
a surface of the boiler.
Inventors: |
LEVASSEUR; ARMAND; (WINDSOR
LOCKS, CT) ; ZHANG; WEI; (SOUTH WINDSOR, CT) ;
STALLMANN; OLAF; (ESSENHEIM, DE) ; NIASS;
TIDJANI; (DHAHRAN, SA) ; YOUNES; MOURAD;
(ABQAIQ, SA) ; JAMAL; AQIL; (RICHMOND,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GENERAL ELECTRIC TECHNOLOGY GMBH |
BADEN |
|
CH |
|
|
Assignee: |
GENERAL ELECTRIC TECHNOLOGY
GMBH
BADEN
CH
|
Family ID: |
60268350 |
Appl. No.: |
15/338574 |
Filed: |
October 31, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F23J 2215/20 20130101;
F22B 37/48 20130101; F28G 9/00 20130101; F23J 3/023 20130101 |
International
Class: |
F23J 3/02 20060101
F23J003/02; F28G 9/00 20060101 F28G009/00 |
Claims
1. A system for removing ash deposits within a boiler comprising: a
soot blower disposed within the boiler, a gas supply line in fluid
communication with the soot blower and a gas source; and wherein
the soot blower is operative to inject compressed gas from the gas
source into the boiler to remove the ash deposits from a surface of
the boiler.
2. The system of claim 1, wherein the compressed gas is carbon
dioxide.
3. The system of claim 1, wherein the gas source is the boiler.
4. The system of claim 3, further comprising: a compressor disposed
downstream of the boiler for compressing a flue gas stream
discharged from the boiler; and wherein the flue gas stream is the
compressed gas.
5. The system of claim 3, further comprising: a compressor disposed
downstream of the boiler for compressing a flue gas stream
discharged from the boiler; a separator disposed downstream of the
compressor that is operative to separate carbon dioxide from the
flue gas stream; and wherein the separated carbon dioxide is the
compressed gas.
6. The system of claim 5, further comprising: a series of
compressors disposed downstream of the separator and operative to
compress the separated carbon dioxide prior to being injected into
the boiler by the soot blower.
7. The system of claim 6, further comprising: a heat exchanger for
heating the separated carbon dioxide prior to being injected into
the boiler by the soot blower; and wherein the heat exchanger heats
the separated carbon dioxide via cooling the flue gas stream.
8. The system of claim 7, wherein the heat exchanger is disposed
downstream of the compressor and upstream of the separator.
9. The system of claim 1 further comprising: a heat recovery system
that includes a particulate remover and a desulferizer, the heat
recovery system operative to recover heat from a flue gas stream
discharged by the boiler; and wherein the compressed gas is heated
by the flue gas stream between the particulate remover and the
desulferizer.
10. The system of claim 1, wherein the boiler is an oxy-fuel
combustion boiler.
11. A method for removing ash deposits within a boiler comprising:
supplying a compressed gas from a gas source via a supply line to a
soot blower disposed within the boiler; injecting the compressed
gas into the boiler via the soot blower so as to remove the ash
deposits from a surface of the boiler.
12. The method of claim 11, wherein the compressed gas is carbon
dioxide.
13. The method of claim 11, wherein the gas source is the
boiler.
14. The method of claim 13 further comprising: compressing a flue
gas stream discharged from the boiler via a compressor disposed
downstream of the boiler; and wherein the flue gas stream is the
compressed gas.
15. The method of claim 13 further comprising: compressing a flue
gas stream discharged from the boiler via a compressor disposed
downstream of the boiler; separating carbon dioxide from the flue
gas stream via a separator disposed downstream of the compressor;
and wherein the separated carbon dioxide is the compressed gas.
16. The method of claim 15 further comprising: compressing, via a
series of compressors disposed downstream of the separator, the
separated carbon dioxide prior to injecting the separated carbon
dioxide via the soot blower into the boiler.
17. The method of claim 16 further comprising: heating the
separated carbon dioxide via a heat exchanger prior to injecting
the separated carbon dioxide via the soot blower into the boiler;
and wherein the heat exchanger heats the separated carbon dioxide
via cooling the flue gas stream.
18. The method of claim 17, wherein the heat exchanger is disposed
downstream of the compressor and upstream of the separator.
19. The method of claim 11 further comprising: recovering heat from
a flue gas stream discharged by the boiler via a heat recovery
system that includes a particulate remover and a desulferizer; and
heating the compressed gas via the flue gas stream between the
particulate remover and the desulferizer.
20. A system for removing ash deposits within a boiler comprising:
a soot blower disposed within the boiler; a gas supply line in
fluid communication with the soot blower and a carbon dioxide gas
storage vessel; and wherein the soot blower is operative to inject
carbon dioxide gas received from the carbon dioxide gas storage
vessel into the boiler to remove the ash deposits from a surface of
the boiler.
Description
BACKGROUND
Technical Field
[0001] Embodiments of the invention relate generally to boilers,
and more specifically, to a system and method for removing ash
deposits within a boiler.
Discussion of Art
[0002] Many power plants utilize boilers that combust fuels, e.g.,
coal, oil, and/or gas, to generate steam which in turn is used to
produce electricity via a steam turbine generator. Such power
plants typically generate and heat steam by using heating surfaces,
e.g., evaporators, superheaters, etc., to transfer thermal energy
produced from combusting a fuel into water and/or steam.
[0003] In addition to producing a flue gas that contains carbon
dioxide ("CO.sub.2"), combustion of a fuel may also produce dust
and ash that accumulates on one or more heating surfaces within a
boiler so as to form ash deposits. Ash deposits on heating surfaces
of a boiler often act as insulators that restrict the ability of
the heating surfaces to transfer heat into the water/steam. In
other words, ash deposits usually result in less heat being
transferred into the water/steam, and more heat leaving the boiler
via a vented flue gas. Thus, ash deposits typically reduce a
boiler's performance/efficiency. As such, ash deposits usually lead
to higher fuel consumption by the boiler and/or other operational
problems.
[0004] On-line, e.g., occurring during boiler operations, removal
of ash deposits by "soot blowing" is a means to retain desired heat
transfer rates by restoring boiler heating surface area, i.e.,
removing ash deposits. Many boilers often use steam for soot
blowing because of its overall cost and availability. Steam,
however, is expensive in countries/locations where water sources
are costly (e.g., in countries/regions where water is produced from
desalination). Further, in many boilers, the steam utilized for
soot blowing is often drawn/tapped from a supply of steam used to
generate electricity, which in turn may reduce the amount of steam
available to generate electricity and result in a power production
loss in the encompassing power plant.
[0005] What is needed, therefore, is an improved system and method
for removing ash deposits within a boiler.
BRIEF DESCRIPTION
[0006] In an embodiment, a system for removing ash deposits within
a boiler is provided. The system includes a soot blower disposed
within the boiler, and a gas supply line in fluid communication
with the soot blower and a gas source. The soot blower is operative
to inject compressed gas from the gas source into the boiler to
remove the ash deposits from a surface of the boiler.
[0007] In another embodiment, a method for removing ash deposits
within a boiler is provided. The method includes: supplying a
compressed gas from a gas source via a supply line to a soot blower
disposed within the boiler; and injecting the compressed gas into
the boiler via the soot blower so as to remove the ash deposits
from a surface of the boiler.
[0008] In yet another embodiment, a system for removing ash
deposits within a boiler is provided. The system includes a soot
blower disposed within the boiler, and a gas supply line in fluid
communication with the soot blower and a carbon dioxide gas storage
vessel. The soot blower is operative to inject carbon dioxide gas
received from the carbon dioxide gas storage vessel into the boiler
to remove the ash deposits from a surface of the boiler.
DRAWINGS
[0009] The present invention will be better understood from reading
the following description of non-limiting embodiments, with
reference to the attached drawings, wherein below:
[0010] FIG. 1 is a schematic block diagram of a system for removing
ash deposits within a boiler in accordance with an embodiment of
the present invention;
[0011] FIG. 2 is another schematic block diagram of the system of
FIG. 1 in accordance with an embodiment of the present
invention;
[0012] FIG. 3 is yet another schematic block diagram of the system
of FIG. 1 in accordance with an embodiment of the present
invention; and
[0013] FIG. 4 is still yet another schematic block diagram of the
system of FIG. 1 in accordance with an embodiment of the present
invention.
DETAILED DESCRIPTION
[0014] Reference will be made below in detail to exemplary
embodiments of the invention, examples of which are illustrated in
the accompanying drawings. Wherever possible, the same reference
characters used throughout the drawings refer to the same or like
parts, without duplicative description.
[0015] As used herein, the terms "substantially," "generally," and
"about" indicate conditions within reasonably achievable
manufacturing and assembly tolerances, relative to ideal desired
conditions suitable for achieving the functional purpose of a
component or assembly.
[0016] The term "real-time," as used herein, means a level of
processing responsiveness that a user senses as sufficiently
immediate or that enables the processor to keep up with an external
process.
[0017] As used herein, "electrically coupled", "electrically
connected", and "electrical communication" mean that the referenced
elements are directly or indirectly connected such that an
electrical current, or other communication medium, may flow from
one to the other. The connection may include a direct conductive
connection, i.e., without an intervening capacitive, inductive or
active element, an inductive connection, a capacitive connection,
and/or any other suitable electrical connection. Intervening
components may be present.
[0018] As also used herein, the terms "fluidly connected" and
"fluid communication" mean that the referenced elements are
connected such that a fluid (to include a liquid, gas, and/or
plasma) may flow along a flow path from one to the other.
[0019] The term "stream," as used herein, refers to the sustained
movement of a substance, e.g., a gas, solid, liquid, and/or
plasma.
[0020] Accordingly, the terms "upstream" and "downstream," as used
herein, describe the position of the referenced elements with
respect to a flow path of a gas, solid, liquid, and/or plasma
flowing between and/or near the referenced elements.
[0021] As also used herein, the term "heating contact" means that
the referenced elements are in proximity of one another such that
heat/thermal energy can transfer between them.
[0022] Additionally, while the embodiments disclosed herein are
described with respect to boilers, it is to be understood that
embodiments of the present invention may be applicable to other
systems and/or processes where accumulated ash needs to be removed
from a surface.
[0023] As will be appreciated, disclosed herein is a system and
method of using pressurized CO.sub.2 or flue gas in place of steam
for soot blowing in a boiler. The system and method facilitate
supplying a compressed gas, e.g., a flue gas and/or CO.sub.2, to a
soot blower from which it is discharged to remove ash deposits from
the internal surfaces of a boiler, e.g., tubes, other parts of a
combustion chamber, and/or evaporators, superheaters, etc. Thus,
some embodiments of the present invention may reduce water
consumption in power plants, which as stated above, is usually
costly in dry regions or other locations where water is
expensive.
[0024] Accordingly, FIGS. 1-4 show various embodiments of a system
for conducting soot blowing in accordance with the present
invention. For example, referring now to FIG. 1, a system 1
including a boiler 2 and a flue gas processing/treatment system 3
is shown.
[0025] The boiler 2 includes a furnace 5 and conventional tube
banks disposed downstream of the furnace 5. The boiler 2 has at
least one soot blower 6 for facilitating soot blowing which is
operative to receive gas via supply line 7 that is fluidly
connected through connection 27 to a gas source, e.g, the boiler 2,
such that the gas flows from the gas source/boiler 2 through the
supply line 7 and into the blower 6 where it is injected into the
boiler 2 via a port 11. In embodiments, the gas utilized by the
blower 6 may be a flue gas generated by the boiler 2 and/or
CO.sub.2 recovered from the flue gas via the flue gas treatment
system 3. In embodiments, the gas may be compressed prior to being
injected into the boiler 2.
[0026] As will be appreciated, in embodiments, the soot blower 6
and port 11 may be a single soot blower 6 port 11 pairing and/or a
plurality of ports 11 fluidly connected to one or more soot blowers
6 disposed at different locations within the boiler 2.
Additionally, in embodiments, the furnace 5 may be an oxy-fuel
combustion furnace, i.e., a combustion furnace/system in which fuel
is combusted with a mixture of recirculated flue gas and pure or
substantially pure oxygen, that provides for the generation of a
flue gas having a high CO.sub.2 content, such as between 75% to 85%
or even more. Thus, in embodiments, the gas injected into the
boiler 2 via the blower 6 may be pure, or substantially pure,
CO.sub.2 gas, or a gas mixture containing CO.sub.2.
[0027] As further shown in FIG. 1, the flue gas treatment system 3
includes a compressor 15 disposed downstream of the furnace 5 which
compresses the flue gas discharged from the furnace 5. While not
shown, it will be understood that the system 1 may include various
Environmental Control Systems ("ECS") and/or a heat recovery system
4 having a particulate remover 8 and/or a desulferizers 12, and/or
nitrogen oxide removers (not shown), disposed downstream of the
boiler 2 and upstream of the compressor 15. In embodiments, the
flue gas treatment system 3 may further include a mercury removal
unit 16 and a dryer 17 disposed downstream of the compressor 15. In
such embodiments, one or more heat exchangers 18, 19 may also be
disposed upstream of the mercury removal unit 16 and the dryer
17.
[0028] The flue gas treatment system 3 may further include a
separation stage 20 that is disposed downstream of the compressor
15 which separates CO.sub.2 from other gases contained in the flue
gas. The separation stage 20 may be fluidly connected to a line 21
for venting gas separated from the CO.sub.2, and further fluidly
connected to a line 22 for supplying the separated CO.sub.2 into a
compressor 23 (typically an intercooled, multistage compressor,
and/or a series of compressors), a pump 24 (for supercritical
CO.sub.2), and storage 25, e.g., a CO.sub.2 storage vessel and/or a
pipeline.
[0029] As shown in FIG. 1, in embodiments, the connection 27 may be
disposed downstream of the compressor 15 and upstream of the
separation stage 20 such that the compressed gas is flue gas coming
from the furnace 5. In such embodiments, the gas supply line 7 is
connected immediately downstream of the compressor 15, i.e. without
any components between the compressor 15 and the connection 27. In
such embodiments, the flue gas diverted to supply line 7 may have a
pressure of about 10 to 15 bar and a temperature of about
110.degree. C. As will be further understood,
compressed/pressurized gas for the blower 6 may also be drawn
downstream from the pump 24 via gas supply line 9 or from the
storage 25 via gas supply line 10. As will be appreciated, the gas
drawn downstream from pump 24 and/or the storage 25 may be pure
and/or nearly pure CO.sub.2. Accordingly, each of the gas supply
lines 7, 9 and 10 may be fitted with valves (not shown) that permit
the flow of the CO.sub.2 to the soot blower 6 from the connection
27, the pump 24, the storage 25, or from any two or more of these
sources.
[0030] Referring briefly to FIG. 2, as will be appreciated, in some
embodiments wherein the compressor 15 is a multistage compressor,
connection 27 may be disposed at an interstage section of the
compressor 15, i.e., gas supply line 7 may draw flue gas from
regions between stages of compressor 15. In such embodiments, a
part of the flue gas at a pressure of about 10 to 15 bar is
diverted through the gas supply line 7 to the soot blower 6.
[0031] Turning now to FIG. 3, another embodiment of the system 1 is
shown having two separation stages 20a, 20b. As will be
appreciated, the separation stages 20a, 20b can be realised in
different ways and according to different technologies. For
example, each separation stage 20a and 20b may include a
condensation step that includes a cooling process to facilitate
separation of CO.sub.2 from the other gases contained in the flue
gas.
[0032] Moving to FIG. 4, in embodiments, connection 27 may be
downstream of the separation stage 20a, 20b such that the gas is
substantially compressed pure, or near pure, CO.sub.2 coming from
the separation stages 20a 20b. While FIG. 4 depicts two separation
stages 20a and 20b, as stated above, embodiments may have a single
separation stage 20 (FIG. 1). As further shown in FIG. 4, a heat
exchanger 28 may be provided for heating the separated CO.sub.2
downstream of connection 27. For example, in embodiments, the heat
exchanger 28 may be disposed downstream of the compressor 15 and
upstream of the separation stages 20a, 20b with respect to the flue
gas discharged by the boiler 2. In such embodiments, a part of the
compressed CO.sub.2 at a pressure between about 10 to 15 bar is
diverted through connection 27 and heated at the heat exchanger 28,
via cooling of the flue gas passing from the compressor 15 to the
mercury removal unit 16, before being forwarded to the blower 6 via
gas supply line 7. In embodiments, the heat exchanger 28 may be
disposed between the particulate remover 8 (FIG. 1) and the
desulferizer 12 (FIG. 1), e.g., in the oxy boiler island.
[0033] Thus, in a method in accordance with embodiments of the
present invention, flue gas produced at the furnace 5 of the boiler
2 is compressed at the compressor 15, treated at the mercury
removal unit 16 and dryer 17 (after cooling in the heat exchangers
18, 19), and then supplied into the separation stage 20 (FIGS. 1
and 2)/20a, 20b (FIGS. 3 and 4). From the separation stage 20
(FIGS. 1 and 2)/20a, 20b (FIGS. 3 and 4), the CO.sub.2 is
discharged and/or supplied to the compressor 23 and pump 24, and
finally fed into a pipeline for use or storage 25, e.g., a CO.sub.2
storage vessel/container. In addition, the gas separated from the
CO.sub.2, e.g., nitrogen, argon, etc., is vented via line 21.
[0034] Continuing, gas is diverted via connection 27 through the
gas supply line 7 to the blower 6, which in embodiments, may be
performed on demand, i.e., whenever it is desirable for accumulated
ash to be blown away from surfaces of the boiler 2. As stated
above, in embodiments, the gas may be flue gas or CO.sub.2
depending on the location of connection 27.
[0035] Additionally, in embodiments where trace impurities, e.g.,
hydrogen disulfide, in the flue gas at the connection 27 cause
corrosion to the blower, or if higher pressures are desired, the
high pressure CO.sub.2 stream exiting the compressor 23 may be
recirculated, thus providing for a compressed high purity CO.sub.2
to be used in the soot blower 6. In such embodiments, the
compressed high purity of CO.sub.2 may have a pressure between
about 16 to 20 bar and be reheated using flue gas from the boiler 2
between to 60 to 90.degree. C. before being injected into the soot
blower 6.
[0036] Finally, returning back to FIG. 1, it is also to be
understood that the system 1 may include the necessary electronics,
software, memory, storage, databases, firmware, logic/state
machines, microprocessors, communication links, displays or other
visual or audio user interfaces, printing devices, and any other
input/output interfaces to perform the functions described herein
and/or to achieve the results described herein. For example, the
system 1 may include at least one processor 30, and system
memory/data storage structures 31 in the form of a controller 32.
The memory 31 may include random access memory (RAM) and read-only
memory (ROM). The at least one processor 30 may include one or more
conventional microprocessors and one or more supplementary
co-processors such as math co-processors or the like. The data
storage structures discussed herein may include an appropriate
combination of magnetic, optical and/or semiconductor memory, and
may include, for example, RAM, ROM, flash drive, an optical disc
such as a compact disc and/or a hard disk or drive.
[0037] Additionally, a software application that provides for
control, which may be in real-time, over one or more of the various
components of the system 1, e.g., the boiler 2, blower 6, etc., may
be read into a main memory of the at least one processor 30 from a
computer-readable medium. The term "computer-readable medium," as
used herein, refers to any medium that provides or participates in
providing instructions to the at least one processor 30 of the
system 1 (or any other processor of a device described herein) for
execution. Such a medium may take many forms, including but not
limited to, non-volatile media and volatile media.
[0038] While in embodiments, the execution of sequences of
instructions in the software application causes the at least one
processor 1 to perform the methods/processes described herein,
hard-wired circuitry may be used in place of, or in combination
with, software instructions for implementation of the
methods/processes of the present invention. Therefore, embodiments
of the present invention are not limited to any specific
combination of hardware and/or software.
[0039] It is further to be understood that the above description is
intended to be illustrative, and not restrictive. For example, the
above-described embodiments (and/or aspects thereof) may be used in
combination with each other. Additionally, many modifications may
be made to adapt a particular situation or material to the
teachings of the invention without departing from its scope.
[0040] For example, in an embodiment, a system for removing ash
deposits within a boiler is provided. The system includes a soot
blower disposed within the boiler, and a gas supply line in fluid
communication with the soot blower and a gas source. The soot
blower is operative to inject compressed gas from the gas source
into the boiler to remove the ash deposits from a surface of the
boiler. In certain embodiments, the compressed gas is carbon
dioxide. In certain embodiments, the gas source is the boiler. In
certain embodiments, the system further includes a compressor
disposed downstream of the boiler for compressing a flue gas stream
discharged from the boiler. In such embodiments, the flue gas
stream is the compressed gas. In certain embodiments, the system
further includes a compressor disposed downstream of the boiler for
compressing a flue gas stream discharged from the boiler; and a
separator disposed downstream of the compressor that is operative
to separate carbon dioxide from the flue gas stream. In such
embodiments the separated carbon dioxide is the compressed gas. In
certain embodiments, the system further includes a series of
compressors disposed downstream of the separator and operative to
compress the separated carbon dioxide prior to being injected into
the boiler by the soot blower. In certain embodiments, the system
further includes a heat exchanger for heating the separated carbon
dioxide prior to being injected into the boiler by the soot blower.
In such embodiments, the heat exchanger heats the separated carbon
dioxide via cooling the flue gas stream. In certain embodiments,
the heat exchanger is disposed downstream of the compressor and
upstream of the separator. In certain embodiments, the system
further includes a heat recovery system that includes a particulate
remover and a desulferizer, and the heat recovery system is
operative to recover heat from a flue gas stream discharged by the
boiler. In such embodiments, the compressed gas is heated by the
flue gas stream between the particulate remover and the
desulferizer. In certain embodiments, the boiler is an oxy-fuel
combustion boiler.
[0041] Other embodiments provide for a method for removing ash
deposits within a boiler. The method includes: supplying a
compressed gas from a gas source via a supply line to a soot blower
disposed within the boiler; and injecting the compressed gas into
the boiler via the soot blower so as to remove the ash deposits
from a surface of the boiler. In certain embodiments, the
compressed gas is carbon dioxide. In certain embodiments, the gas
source is the boiler. In certain embodiments, the method further
includes compressing a flue gas stream discharged from the boiler
via a compressor disposed downstream of the boiler. In such
embodiments, the flue gas stream is the compressed gas. In certain
embodiments, the method further includes: compressing a flue gas
stream discharged from the boiler via a compressor disposed
downstream of the boiler; and separating carbon dioxide from the
flue gas stream via a separator disposed downstream of the
compressor. In such embodiments, the separated carbon dioxide is
the compressed gas. In certain embodiments, the method further
includes compressing, via a series of compressors disposed
downstream of the separator, the separated carbon dioxide prior to
injecting the separated carbon dioxide via the soot blower into the
boiler. In certain embodiments, the method further includes heating
the separated carbon dioxide via a heat exchanger prior to
injecting the separated carbon dioxide via the soot blower into the
boiler. In such embodiments, the heat exchanger heats the separated
carbon dioxide via cooling the flue gas stream. In certain
embodiments, the heat exchanger is disposed downstream of the
compressor and upstream of the separator. In certain embodiments,
the method further includes: recovering heat from a flue gas stream
discharged by the boiler via a heat recovery system that includes a
particulate remover and a desulferizer; and heating the compressed
gas via the flue gas stream between the particulate remover and the
desulferizer.
[0042] Yet still other embodiments provide for a system for
removing ash deposits within a boiler. The system includes a soot
blower disposed within the boiler, and a gas supply line in fluid
communication with the soot blower and a CO.sub.2 gas storage
vessel. The soot blower is operative to inject CO.sub.2 gas from
the CO.sub.2 gas storage vessel into the boiler to remove the ash
deposits from a surface of the boiler.
[0043] Accordingly, by supplying compressed gas containing CO.sub.2
withdrawn from part of flue gas at an interstage during multistage
compression and/or downstream of the compressor and/or upstream of
the separator, and/or withdrawing at least a part of the separated
CO.sub.2, some embodiments provide for the ability to blow
accumulated ash off of surfaces in a boiler without the use of
steam. Thus, some embodiments provide for a more efficient system
and method for soot blowing in arid environments where it may be
desirable to conserve water.
[0044] While the dimensions and types of materials described herein
are intended to define the parameters of the invention, they are by
no means limiting and are exemplary embodiments. Many other
embodiments will be apparent to those of skill in the art upon
reviewing the above description. The scope of the invention should,
therefore, be determined with reference to the appended claims,
along with the full scope of equivalents to which such claims are
entitled. In the appended claims, the terms "including" and "in
which" are used as the plain-English equivalents of the respective
terms "comprising" and "wherein." Moreover, in the following
claims, terms such as "first," "second," "third," "upper," "lower,"
"bottom," "top," etc. are used merely as labels, and are not
intended to impose numerical or positional requirements on their
objects. Further, the limitations of the following claims are not
written in means-plus-function format and are not intended to be
interpreted as such, unless and until such claim limitations
expressly use the phrase "means for" followed by a statement of
function void of further structure.
[0045] This written description uses examples to disclose several
embodiments of the invention, including the best mode, and also to
enable one of ordinary skill in the art to practice the embodiments
of 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 one of ordinary skill 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.
[0046] As used herein, an element or step recited in the singular
and proceeded with the word "a" or "an" should be understood as not
excluding plural of said elements or steps, unless such exclusion
is explicitly stated. Furthermore, references to "one embodiment"
of the present invention are not intended to be interpreted as
excluding the existence of additional embodiments that also
incorporate the recited features. Moreover, unless explicitly
stated to the contrary, embodiments "comprising," "including," or
"having" an element or a plurality of elements having a particular
property may include additional such elements not having that
property.
[0047] Since certain changes may be made in the above-described
invention, without departing from the spirit and scope of the
invention herein involved, it is intended that all of the subject
matter of the above description shown in the accompanying drawings
shall be interpreted merely as examples illustrating the inventive
concept herein and shall not be construed as limiting the
invention.
* * * * *