Title of Invention

CIRCULATING FLUIDIZED BED REACTOR

Abstract The invention relates to a circulating fluidized bed reactor, in particular) for the burning of fuels, consisting of a reactor chamber (2), at least one drawing off device (4) for drawing off a flue gas with the entrained solid particles from the reactor chamber (2), at least cyclone separator (5) that is connected from the flue gas, at least one device for the recirculation of at least a portion of the solid particles separated from the cyclone separator (5) into the reactor chamber (2), whereby the recirculation device exhibits a siphon—trap—like gas seal (7, 8, 9), a device (10) for fluidizing the separated portion and a device (12, 13, 14) for connecting the gas seal (7, 8, 9) with the reactor chamber (2). The riser (9) of the gas seal (7, 8, 9) is designed at its upper end and at the circumference with the outlet openings (11) that point essentially in the direction of the reactor chamber (2), and each outlet opening (11) is connected with the reactor chamber (2) by a device ( 12, 13, 14).
Full Text Description
Circulating Fluidized Bed Reactor
The invention pertains to a circulating fluidized bed reactor.
Such fluidized bed reactors are used in power engineering and power plant engineering, among
other applications. There, coal or other combustible materials, such as trash or biomasses, for
example, are burned in the fluidized bed of the reactor combustion chamber. In order to
separate and recirculate a portion of the solid particles contained in the flue gas back into the
reactor chamber, the fluidized bed reactor exhibits a centrifugal separator, generally a cyclone
separator. In conjunction with this, the separated solid particles are fluidized prior to their
recirculation into the combustion chamber, and are conveyed to the combustion chamber inlet
openings in order to be distributed essentially uniformly over the width of the fluidized bed.
Such a fluidized bed reactor has become known from specification EP 0 161 970 B1. The
technical teaching of this document provides that separated solids are drawn from the cyclone
separator by means of a vertical standpipe. At its lower end, the standpipe leads to the center of
a duct that is placed horizontally and parallel to the back wall of the combustion chamber, and
from each of the two ends of the horizontal duct, a pipe leads first vertically upward and then
inclined diagonally downward into the combustion chamber. In order to distribute the solid
material within the horizontal duct and continue the conveyance, a fluidizing device, which
exhibits multiple air chambers and through which a fluidizing gas, usually air, is supplied, is
provided inside the horizontal duct.
In this known arrangement of the recirculation of solids into the combustion chamber, it proves
to be disadvantageous that, due to the protruding horizontal duct underneath the standpipe,
there is a large space requirement in the area of this duct and as a result, the design cannot be
executed in a compact fashion. This has a negative effect on the placing of the surrounding
components such as the coaling conveyers, for example, which have to be placed at a greater
distance from the coal discharge into the recirculation pipes. In addition, markedly more

fluidizing air is needed for the fluidization of this horizontal
duct than is the case in facilities that have only a
recirculation pipe and thus no horizontal duct.
It is thus the task of this invention to create a fluidized bed
reactor whichexhibitsacompactandspace—saving solids
recirculation pipe, and by means of which the recirculated solids
can be supplied or fed, distributed uniformly across the width of
the combustion chamber, to the fluidized bed.
Using the solution according to the invention) a circulating
fluidized bed reactor is created that exhibits the following
advantages,
- compact design,
- more favorable arrangement of the coalconveyorsin
terms of the coal discharge into the recirculation
Pipe,
- less need for fluidization air,
- more uniform appointment of the recirculated ashto
the two recirculation pipes.

in an advantageous form of the invention, the two outlet openings
of the gas—seal riser are placed at the same height and at an
angle of 60 to 180 to each other. As a result of the placement
of the same height, uniform distribution of the solid particles
to the two pipes can be achieved.
£n an especially advantageous form of the invention, the two
outletopeningsof the gas-seal riser are placedatthesame
height and at an angle of 90 to each other. Along with the
uniform distribution of the solid particles, an especially
compact form of the invention is achieved.

It is expedient to place the two outlet openings of the gas-seal riser symmetrical to the
longitudinal axis of the recirculation device. Along with the compact design, a simple structural
solution is thus achieved as well.
An advantageous further development of the invention provides that the devices for connecting
the gas-seal riser outlet openings with the reactor chamber inlet openings each essentially
exhibit, starting from the outlet openings, a connecting piece that is inclined downward and at an
angle of 30 to 90° to the longitudinal axis of the recirculation device, a connecting part that
adjoins the connecting piece and runs perpendicularly downward, and adjoining that, a
connecting part that is inclined downward. By means of this development, a design is made
available that is easy to produce and extremely reliable during operation of the facility.
A further advantageous form of the invention provides for placing the connecting pieces after
the riser symmetrical to each other in order thereby to achieve a solution that is simple in design
and operation.
Embodiments of the invention are described below in more detail with the aid of the (drawing and
the description.
The following are shown:
Fig. 1 a schematic representation of a fluidized bed reactor in section across its height,
Fig. 2a schematic representation of a fluidized bed reactor in cross section according to
section A-A in Figure 1,
Fig. 3 the front view of a portion of the recirculation pipe according to view B in Figure 2,
Fig. 4 the side view of a portion of the recirculation pipe according to view C in Figure 2,

Fig. 5 the cross section of a portion of the recirculation pipe according to section D-D in
Figure 4.
Figure 1 shows a schematic representation of a circulating fluidized bed reactor 1 that exhibits a
reactor chamber or combustion chamber 2. The fluidized bed reactor 1 can be a gasification
reactor, a combustion reactor, a steam generator or another reactor or device known to the
person skilled in the art. Primary and secondary gases or air are sent to the reactor chamber 2
through the bottom and the side walls by means of facilities that are not shown. Each of the two
cyclone separators 5 is connected by means of an opening 3 with the upper end of the reactor
chamber 2. Ducts 4 connect the outlet openings 3 with the cyclone separators 5. The flue gas
that is generated in the reactor chamber 2 is directed from the reactor chamber 2 through the
outlet openings 3 and through the ducts 4 into the cyclone separators 5. In conjunction with that,
the ducts 4 are placed in such a way that they direct the solids-charged flue gas into the cyclone
separators 5 tangentially. The cyclone separators 5 separate the hot flue gas from the solid
particles, which arrive at the lower, conical region of the cyclone chambers 6 as the result
of gravity.
Each of the lower, conical regions of the chambers 6 of the two cyclone separators 5 is
connected to a standpipe 7, through which the solids collected in the conical region are drawn
off and sent to a siphon-trap-like gas seal 7, 8, 9. In that regard, the gas seal 7, 8, 9 is formed
by two essentially vertical pipes, first by the standpipe 7 and second by the riser 9, which are
connected to each other by a horizontal duct 8 and which both communicate with each other. In
an advantageous form of the invention, the longitudinal axis of the horizontal duct 8, which also
corresponds to the recirculation device longitudinal axis 17, is aligned parallel to the longitudinal
axis 16 of the reactor chamber 2. If design measures require it, it would also be possible to
place the recirculation device longitudinal axis 17 at an angle to the longitudinal axis 16 of the
reactor chamber 2. The gas seal 7, 8, 9, in which solids collect up to the height of the lower
edge of the outlet openings 11 located at the upper end of the riser 9 and placed at the
circumference, prevents an unwanted escape of flue gases from the reactor chamber 2 through

the solids recirculation pipe in the direction of the cyclone separators 5. The axial upper end of
the riser 9 is made leakproof.
In order that the solid particles to be recirculated that are collecting in the gas seal 7, 8, 9 do not
become compacted and deposited, fluidizing gas or air is supplied by means of a fluidizing
device 10 essentially from beneath the gas seal or horizontal duct 8. Compacting of the solid
particles is prevented in this way, and the transport of the solids in the direction of the reactor
chamber 2 is maintained.
According to Figures 2 through 5, the riser 9 is designed at its upper end with two outlet
openings 11 that are placed at the circumference and advantageously located at the same
height. In conjunction with that, the outlet openings 11 are placed essentially in the direction of
the reactor chamber 2, and specifically, starting at the recirculation device longitudinal axis 17,
advantageously to both sides at 30 to 90°, and especially advantageously at 45°, so that the two
outlet openings 11 are placed at an angle to each other of between 60 and 180° or 90°,
respectively. From the outlet openings 11 in an extension of the outlet angle, downwardly
inclined connecting pieces 12 lead to connecting parts 13 that run vertically downward and that
in turn lead to downwardly inclined connecting parts 14. The two connecting parts 14 can be
placed parallel to each other and, in an advantageous further development of the invention,
parallel to the reactor chamber longitudinal axis 16 or the recirculation device longitudinal axis
17, and are at a distance from each other. The lower end of each of the connecting parts 14
runs into the reactor chamber 2 inlet openings 15, through which the solid particles that are to
be recirculated by means of the recirculation pipe are returned to the reactor chamber 2.
Both of the inlet openings 15 are placed at the same height in the lower region of the reactor
chamber 2, and the distances of the inlet openings 15 viewed across the width of the reactor
chamber 2, and thus the placement of the connecting parts 14 as well, are formed in such a way
that an essentially uniform distribution of the solid particles returned to the reactor chamber 2
takes place. Along with the returned ash or solid particles, the fuel that is fed into the connecting

parts 13 and 14 of the recirculation pipe by means of a feed pipe 18 after the siphon-trap-like
gas seal is also distributed uniformly in the combustion chamber 2.
Through the inventive design of the recirculation pipe and the separation of the recirculation
pipe first at the riser 9, a significantly more compact design is achieved because a wide solids
distribution station or distribution duct is no longer required, and as a result the fuel transport
system (not shown) into the recirculation pipe is simplified substantially. In addition, no complex
fluidization device 10 is needed at the horizontal duct 8, and in comparison with the known
design according to the state of the art, substantially less fluidization air is needed as well,
which results in a reduction of the need for electric power for the fluidization compressor.
Figure 2 shows a fluidized bed reactor 1 according to the invention with two cyclone separators
5. Depending on the design of the reactor 1, more specifically, its width, the reactor 1 can also
be equipped with one or more than two cyclone separators 5.

WE CLAIMS
1.Circulating fluidized bed reactor, in particular,for
the burning of fuels, consisting of a reactor chamber at least one drawing off device (4) for drawing off a
flue gas with the entrained solid particles from the reactor
chamber (2),
at least one cyclone separator (5) that is connected
with the drawing off device (4) for separating solid particles
from the flue gas*
at least one device for the recirculation of at least a
portion of the solid particles separated from the cyclone
separator (5) into the reactor chamber (2)»
whereby the recirculation device exhibits a siphon-
trap-like gas seal (7, 8, 9), a device (10) for fluidizing the
separated portion and a device ( 12, 13, 14) for connecting the
gas seal (7, 8, 9) with the reactor chamber (2),
characterized in that

List of Reference Symbols:
1 Circulating fluidized bed reactor
2 Reactor chamber or combustion chamber
3 Outlet opening
4 Duct between reactor outlet opening and cyclone separator
5 Cyclone separator
6 Separator chamber
7 Standpipe
8 Horizontal duct
9 Riser
10 Fluidizing device
11 Outlet opening
12 Connecting piece
13 Connecting part
14 Connecting part
15 Inlet opening
16 Reactor chamber longitudinal axis
17 Recirculation device longitudinal axis
18 Fuel feed

the ristr (9) of the gas seal (7, 8, 9) is designed at
its upper and and at the circumference with two outlet openings
(11) that point essentially in the direction of the reactor
chamber (2), and each outlet opening (11) is connected with the
reactor chamber (2) by a device (12, 13* 14).
2. Circulating fluidized bed reactor as claimed in claim
1* wherein the two outlet openings (11) are placed at the same
height and at an angle of between 60 and 180°to each other.
3. Circulating fluidized bed reactor as claimed in claim
1, wherein the two outlet openings (11) are placed at the same
height and at an angle of90°to each other.
4. Circulating fluidized bed reactor as claimed in one of
the claims1 to 3, wherein the two outlet openings (11)are
placed symmetrical to the recirculation device longitudinal axis
(17) .
5. Circulating fludized bed reactor as claimed in one of
the claims 1 to 4, wherein the devices for connecting the outlet
openings (11) with the reactor chamber inlet openings (15),
startingfromtheoutletopenings(11),eachcomprises a

connecting piece (12) that is inclined downward and at an angle
of 30 to 90° to the recirculation device longitudinal axis (17),
a first connecting part (13) that adjoins the connecting piece
(12) and runs perpendicularly downward* and adjoining that, a
second connecting part (14) that is inclined downward.
6. Circulating fluidized bed reactor as claimed in claim
5* wherein the connecting pieces (12) are placed symmetrically to
each other.
7. Circulating fluidized bed reactor as claimed in one of
the claims 5 or 6* wherein the second connecting parts (14) are
placed parallel to the reactor chamber longitudinal axis (16) or
the recirculation device longitudinal axis (17).
8. Circulating fluidized bed reactor as claimed in one of
the preceding claims* wherein the reactor chamber inlet opening
(15) is placed in the lower region of the reactor chamber (2).

The invention relates to a circulating fluidized bed

reactor, in particular) for the burning of fuels, consisting of a
reactor chamber (2), at least one drawing off device (4) for
drawing off a flue gas with the entrained solid particles from
the reactor chamber (2), at least cyclone separator (5) that is
connected from the flue gas, at least one device for the
recirculation of at least a portion of the solid particles
separated from the cyclone separator (5) into the reactor chamber
(2), whereby the recirculation device exhibits a siphon—trap—like
gas seal (7, 8, 9), a device (10) for fluidizing the separated
portion and a device (12, 13, 14) for connecting the gas seal (7,
8, 9) with the reactor chamber (2). The riser (9) of the gas seal
(7, 8, 9) is designed at its upper end and at the circumference
with the outlet openings (11) that point essentially in the
direction of the reactor chamber (2), and each outlet opening (11)
is connected with the reactor chamber (2) by a device ( 12, 13,
14).

Documents:

15-KOL-2004-(06-03-2012)-ASSIGNMENT.pdf

15-KOL-2004-(06-03-2012)-CERTIFIED COPIES(OTHER COUNTRIES).pdf

15-KOL-2004-(06-03-2012)-CORRESPONDENCE.pdf

15-KOL-2004-(06-03-2012)-FORM-13.pdf

15-KOL-2004-(06-03-2012)-FORM-6.pdf

15-KOL-2004-(06-03-2012)-PA-CERTIFIED COPIES.pdf

15-KOL-2004-(07-06-2013)-CORRESPONDENCE.pdf

15-KOL-2004-(09-03-2012)-CORRESPONDENCE.pdf

15-KOL-2004-(09-03-2012)-OTHERS.pdf

15-KOL-2004-(18-10-2013)-CORRESPONDENCE-1.2.pdf

15-KOL-2004-(18-10-2013)-FORM-13.pdf

15-KOL-2004-(18-10-2013)-PA.pdf

15-KOL-2004-(20-05-2013)-CORRESPONDENCE.pdf

15-KOL-2004-(20-12-2013)-AMANDED CLAIMS.pdf

15-KOL-2004-(20-12-2013)-CORRESPONDENCE.pdf

15-KOL-2004-(20-12-2013)-FORM-1.pdf

15-KOL-2004-(20-12-2013)-FORM-2.pdf

15-KOL-2004-(28-02-2013)-CORRESPONDENCE.pdf

15-KOL-2004--(20-12-2013)-AMANDED CLAIMS.pdf

15-KOL-2004--(20-12-2013)-CLAIMS.pdf

15-KOL-2004--(20-12-2013)-CORRESPONDENCE.pdf

15-KOL-2004--(20-12-2013)-FORM-1.pdf

15-KOL-2004--(20-12-2013)-FORM-2.pdf

15-kol-2004-abstract.pdf

15-kol-2004-claims.pdf

15-KOL-2004-CORRESPONDENCE 1.1.pdf

15-kol-2004-correspondence.pdf

15-kol-2004-description (complete).pdf

15-kol-2004-drawings.pdf

15-kol-2004-examination report.pdf

15-kol-2004-form 1.pdf

15-kol-2004-form 18.pdf

15-kol-2004-form 2.pdf

15-kol-2004-form 26.pdf

15-KOL-2004-FORM 3 1.1.pdf

15-kol-2004-form 3.pdf

15-kol-2004-form 5.pdf

15-KOL-2004-OTHERS.pdf

15-kol-2004-priority document.pdf

15-kol-2004-reply to examination report.pdf

15-kol-2004-specification.pdf

15-kol-2004-translated copy of priority document.pdf


Patent Number 263568
Indian Patent Application Number 15/KOL/2004
PG Journal Number 45/2014
Publication Date 07-Nov-2014
Grant Date 31-Oct-2014
Date of Filing 09-Jan-2004
Name of Patentee ALSTOM TECHNOLOGY LTD.
Applicant Address BROWN BOVERI STRASSE 7, CH-5400 BADEN
Inventors:
# Inventor's Name Inventor's Address
1 SEEBER, JOACHIM GOETHESTR. 64 D-73249 WERNAU
PCT International Classification Number C10J3/54,F23C11/02
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10300838.1 2003-01-10 Germany