[0001] The invention relates to a fluidized bed heat exchanger as a component of an associated
Incineration apparatus, in particular to a so-called Circulating Fluidized Bed Apparatus
(CFBA). Hereinafter terms like "upper", "lower", "horizontal", "vertical", "inner"
etc. always refer to a regular use position of the heat exchanger and/or the CFBA.
[0002] A CFBA typically comprises a circulating fluidized bed reactor, designed as a combustor,
incineration reactor, boiler, gasifier, steam generator etc., hereinafter called combustor.
[0003] The combustor walls are made of tubes, through which water runs, wherein said tubes
are either welded directly to each other to provide a wall structure or with fins/ribs
between parallel running tube sections.
[0004] As most of corresponding fossil fuels like coal, timber etc. contain sulphur and/or
harmful substances It Is necessary to clean the gases leaving the combustor, In a
suitable way.
[0005] Typically the combustor has at least one outlet port at its upper end, wherein said
outlet port allows a mixture of gas and solid particles (hereinafter called solids
or ash) exhausted from the reactor, to flow Into at least one associated separator.
[0006] The separator serves to disengage the flue gases and solids. Thereafter the separated
flue gases and solids are treated separately. The solids are either directly returned
into the combustor and/or fed Into an intermediate heat exchanger, in particular into
at least one Fluidized Bed Heat Exchanger (FBHE) via a corresponding inlet opening
of said FBHE.
[0007] A syphon along the way from the separator to the FBHE and/or to the combustor allows
decoupling of pressure (fields) between separator and combustor or separator and FBHE
respectively.
[0008] The at least one FBHE allows to use the heat, provided by the solids (particulate
material), for generating power, for example to heat up and/or Increase the pressure
of a steam or water, transported as a heat transfer medium via tubes through said
FBHE and further to turbines or the like.
[0009] The FBHE is equipped with at least one outlet opening, also called return means,
for at least part of the solids on their way out of the FBHE and back Into the combustor.
[0010] The general design of such CFBA and its components is disclosed in
EP 495296 A2.
[0011] The typical electrical capacity range of a generic FBHA is around 50 to 600MW and
the combustor has a height between 30-60m, a width between 13-40m and a depth: 15-40m.
Typical sizes of an FBHA are: height: 3-8 m, width: 3-8 m, depth 3-8 m.
[0012] While the overall functionality and reliability of such CFBA, including the FBHE
(also called ash cooler) has proven successful over years there is a continuous demand
for Improvements.
[0013] Against this background it Is an object of the Invention to provide an FBHE for installation
between a separator and a combustor of a CFBA which provides optimizations in construction,
maintenance, service, efficiency and/or solids' flow (avoidance of plugging).
[0014] The general process engineering of this type of a fluidized bed heat exchanger Is
more or less defined and includes:
- feeding the solids via an inlet opening,
- fluidizing the solids by air, introduced under pressure via corresponding nozzles
In the bottom area of the heat exchanger,
- transferring the energy (heat), stored within the solids, via heat transfer means
(in particular tubes, through which a heat transfer fluid like water or steam flows),
arranged in the heat exchanger, Into said fluid,
- withdrawing the solids from the heat exchanger via a corresponding outlet opening.
[0015] Insofar the invention Is based on the idea to improve the heat transfer within the
heat exchange chamber by optimizing the supply/transport of the solids Into the heat
exchange zone of the heat exchanger, to avoid any plugging within the heat exchange
zone and to extract the solids continuously to allow a continuous flow of the solids
within the heat exchanger.
[0016] In this respect It has been realized that introducing the solids into the heat exchanger
at its bottom end (as disclosed In
EP 495296A2) has the disadvantages that additional power Is required to feed the solids.
[0017] US 6,293,781 discloses an apparatus for decreasing attack of detrimental components of solid particle
suspensions in a heat transfer chamber. The solids are fed into the heat transfer
chamber via a free passage and a transfer chamber, which Is arranged between said
heat transfer chamber and an adjacent dilution chamber, while the solids leave the
heat transfer chamber through a common opening with the associated reactor.
[0018] If the solids are transported into the heat exchanger via an inlet opening at an
upper end of the heat exchange zone It was realized that the thus initiated counter-flow
of the solids and the air introduced by the bottom area of the heat exchange zone
leads to an irregular distribution of the solids within the heat exchange zone and
correspondingly to a loss of heat transfer efficiency.
[0019] These drawbacks can be avoided by a design, characterized by a special feeding channel
(runner) to guide the solids from an inlet opening at an upper end of the heat exchanger
downwardly towards the bottom area of the heat exchanger, wherein no or substantially
no air Is introduced into the solids' stream flowing within the runner, before the
solids leave the runner at a lower end of the runner. The flow direction of the solids
along the runner is therefore substantially downwardly with no or no substantial counterflow
within the runner.
[0020] This outlet end of the runner is close to the bottom of the heat exchanger, and allows
to transfer the solids Into the associated (adjacent) heat transfer zone of the heat
exchanger.
[0021] This heat transfer zone can be designed In a conventional way, namely with a fluidized
bottom (nozzle bottom, grate) to allow a fluidization of the solids and an optimized
heat transfer Into heat transfer means arranged in said heat transfer zone and means
to extract the solids from the heat exchanger. Contrary to the solids' flow direction
within the runner the main flow direction of the solids In the heat transfer zone
is upwardly and again without or with no substantial counterflow, notwithstanding
the fluidizing effect caused by the fluidized bottom of the heat transfer zone.
[0022] The runner is a part and an important component of the heat exchanger and allows
said downwardly oriented flow of the solids. It provides the advantage of an inlet
opening at the upper end of the heat exchanger, in particular close to or in its ceiling
and thus at a short distance to the associated separator which is arranged above the
heat exchanger. The material flow can be affected by gravity with no or little external
power being required,
[0023] As the solids may flow within the runner without any substantial external forces,
in particular without any air supply and as there are no heat transfer means within
the runner space, the solids' stream can be controlled easily and effectively. Any
counter-flows can be avoided along the runner space.
[0024] This design does not exclude means to break up (loosen up) the solids'stream on Its
way along/through the runner. These means can be: mechanical mixing means, vibration
or pulsation means arranged at runner walls or within the runner space, spiral conveyors
within the runner space or air nozzles, blowing air bubbles Into the solids's stream,
whlthout Influencing the main flow direction of the solids through the runner.
[0025] The heat transfer zone and the runner can be arranged side by side and with a common
wall to achieve a compact design.
[0026] A type of a transition region Is arranged beneath the lower end of feeding channel
(runner), which extends into the adjacent heat exchange zone of the heat exchanger.
Along this transition region the material flow makes a substantially 90 degrees turn
(from a substantially vertical and downwardly oriented movement Into a substantially
horizontal flow), before the solids get under the influence of the fluidized bed of
the heat exchange zone, which pushes the solids' stream upwardly, while at the same
time fluidizing the solids. It Is important that the heat exchange zone again is designed
In such a way to avoid any substantial counter flow between air and solids.
[0027] To allow a smooth movement of the solids from the runner into the heat exchange zone
a baffle, In particular a curved baffle, may be provided and installed within the
transition region.
[0028] In Its most general embodiment the Invention provides a fluidized bed heat exchanger
according to claim 1.
[0029] Although the outer shape of the heat exchanger is not crucial, a box-shaped (cubic)
apparatus with 4 vertical outer walls, a horizontal (lower) bottom and a horizontal
(upper) ceiling is a favourable design and is the starting point for the following
disclosure, but not limiting the scope of the invention.
[0030] Accordingly the inlet opening can be arranged in the ceiling, while the outlet opening
is a part of an outlet channel, which outlet channel extends from said heat exchange
zone through said runner to a corresponding aperture In the outer vertical wall of
the heat exchanger. This gives the solids' stream a loop-shape, as will be further
explained with reference to the attached drawing.
[0031] In an embodiment characterized by an Inlet opening at the very top end of the heat
exchanger the outlet channel and the outlet opening are arranged at a lower elevation
than the Inlet opening, which again optimizes the overall flow behaviour of the solids
within the heat exchanger.
[0032] A very compact design provides for a heat exchanger, wherein an outer vertical wall
of the heat exchanger constitutes an outer wall of the runner, I.e. the runner extends
substantially parallel to one of the outer vertical walls while the opposite wall
extends between opposite wall sections of the heat exchanger. This design allows to
build a runner with a horizontal cross section being characterized by a length being
larger than its width, for example 2:1 to 8:1.
[0033] In a similar embodiment, three outer vertical walls of the heat exchanger constitute
three outer walls of the runner and a fourth wall of the runner is provided by a partition
wall, which extends between two opposing outer vertical walls of the heat exchanger.
[0034] The heat exchange zone comprises a number of heat exchange means, preferably designed
as tubes and arranged at a distance to each other to provide chamber like compartments
between adjacent heat exchange tubes. The tubes as such as well as their orientation
within the heat exchange chamber belong to prior art. For example, one or more of
said heat exchange tubes can be arranged in a wall-like pattern and/or mounted in
an outer wall of the heat exchanger.
[0035] The new construction of the heat exchanger allows further improvements with respect
to the heat exchange means. One favourable arrangement is achievable, if one or more
of said heat exchange tubes are mounted in a discrete and detachable section of an
outer wall of the heat exchanger. This allows to dismantle part of the outer wall
of the heat exchanger and thus to pull the heat transfer means out of the heat exchange
zone, for replacement purposes, for maintenance purposes etc.
[0036] At the same time, the fitting of the heat exchange means becomes much easier.
[0037] Another advantage, which results from the described detachable arrangement of the
heat transfer means, is the opportunity to select that part of the outer vertical
wall of the heat exchanger for fitting the heat transfer means, which provides the
largest space adjacent to said wall. In numerous plants that will be the wall which
is arranged parallel to but at a distance to the combustor wall. This Is true In particular
in arrangements where the heat exchanger has a common wall with the combustor. Heat
transfer tubes, arranged in a wall-like pattern and at a distance to each other, then
extend substantially perpendicular to the combustor wall.
[0038] A similar arrangement is achievable if one or more of said heat exchange tubes are
mounted In a discrete and detachable section of a vertical outer wall of the heat
exchanger, In particular the vertical outer wall, which extends opposite to the outer
wall, which is part of the runner.
[0039] The heat transfer means, even If arranged in a so-called "wall like pattern" (which
may be realized, for example, be a meandering profiling of a tube) do allow a substantial
amount of the solids to pass through these "heat exchange walls", for example through
spaces provided between adjacent tube sections. It Is also possible to arrange the
outlet opening of the heat exchanger In a wall section, which extends parallel to
these wall like heat exchangers.
[0040] As already mentioned above the heat exchanger may comprise a baffle downstream of
the runner, to redirect the stream of solids from a predominantly vertical and downwardly
oriented direction within the runner into a predominantly horizontal direction when
entering the heat exchange zone. The baffle can be a discrete construction part of
formed in-situ by a corresponding shape of the outer wall of the heat exchanger.
[0041] The described heat exchanger Is typically used as part of an Incineration apparatus,
comprising a fossil, fuel fired combustor with at least one outlet port at Its upper
end, wherein said outlet port allows a mixture of gas and solids exhausted from said
combustor to flow into at least one associated separator for separating said solids
from said gas, means to transfer at least part of said separated solids from said
separator into at least one of said fluidized bed heat exchangers, wherein the outer
wall of the heat exchanger, comprising the outlet opening, can form a common wall
with an outer combustor-wall. This common wall can be the outer wall of the runner.
[0042] Further features of the Invention are disclosed in the subclaims and the other application
documents.
[0043] The invention will now be described with reference to the attached drawing, showing
in a very schematic away in
Fig 1: a vertical cross section of an embodiment of a heat exchanger
Fig 2:a horizontal cross section of this embodiment of a heat exchanger
[0044] In the Figures identical construction parts or construction parts of same or similar
function are displayed by the same numeral.
[0045] Fig. 1 shows a circulating fluidized bed heat exchanger 10 for use in a circulating
fluidized bed apparatus of the type mentioned above. The heat exchanger is box shaped
with six outer walls, a ceiling (upper wall) 12, four vertical outer walls 14 a, b
,c, d and a lower bottom 16.
[0046] One of the four vertical side wall 14 a,b,c,d, namely wall 14a, displayed on the
left In Fig. 1, is part of an outer wall CW of an associated combustor C.
[0047] Close to the combustor wall CW, the ceiling 12 provides an inlet opening 18 for a
stream of solids (ash), which derives from an associated separator (not displayed,
as known in prior art). The flow direction at Inlet opening 18 is symbolized by arrow
I. The inlet opening 18 is followed by a so-called runner 20, which is a channel along
which the solids flow downwardly until the end of the runner at a distance to the
bottom 16 of the heat exchanger. Typically the solids stream has free-flow properties
on its way through runner 20.
[0048] This open lower end of runner 20 is provided by a shortened Inner wall 22, which
extends parallel to wall 14a, while side walls of runner 20 are provided by corresponding
sections of the two vertical walls 14b, 14d, being the sections adjacent to wall 14a.
[0049] This channel (runner 20) is free of any heat transfer means, although Its outer walls
14a, 14v, 22, 14d can be designed as heat transfer walls.
[0050] It is further important that no air is blown into the stream of solids passing said
runner 20 and Insofar this embodiment is characterized by a non-fluidized bottom section
16r at Its part beneath runner 20. Nevertheless, if appropriate, means like vibrators
to break up the solids stream (to avoid any clogging effects) may be arranged along
or within the runner section.
[0051] A space between runner 20 and bottom section 16r Is called transition area TR as
the solids are redirected In that zone from a substantially vertical downward-movement
(along runner 20) into a substantially horizontal flow, when passing the gap between
the lower end 22e of inner wall 22 and bottom 16, wherein the solids flow is symbolized
by arrow U.
[0052] That part of bottom 16, which extends after said gap (transfer passage) is designed
as a conventional fluidized bottom and referenced 16c. As a fluidized bottom is state
of the art it will not be explained here in more detail. It is the main object of
such bottom to allow air or gases to pass through said bottom and to enter the space
above said bottom 16c, being the heat transfer zone 40 of the heat exchanger 10. Typically
air is blown In via corresponding nozzles, symbolized in the Figures by arrow A.
[0053] As can best be seen in Fig. 2 a number of wail-like heat transfer tubes 42a-e are
arranged within said heat transfer zone 40, being tubes, through which water or steam
as a heat transfer fluid flows. Each "heat transfer wall" is characterized by a meandering
run of the corresponding tube(s), symbolized In Fig. 1 by six loops 42t for one heat
transfer tube 42a, with a distance between adjacent tubes sections to allow the solids
to pass through said "wall". Each tubes 42a-e is mounted In wall 14c and fluidly connected
to a central feeding line 43 at its end, protruding wall 14c of the heat exchanger
10.
[0054] The tubes 42a-e are arranged at a distance to each other so that chamber like compartments
45 are arranged between adjacent tubes 42a,b; 42b,c; 42c,d; 42d,e.
[0055] Each of said tubes (walls) 42a-e is mounted in the outer vertical wall 14c of the
heat exchanger 10 In a way to allow Individual replacements at any time. For this
purpose the corresponding mounting section for each of said heat transfer tubes 42a-e
is a detachable part of said wall 14c and displayed by numeral 44. This allows to
fit or extract the tubes 42a-e individually or In groups at any time. The preferred
mounting and extracting path Is symbolized by arrow M in Fig. 2.
[0056] This Is the same direction along which the solids leave the heat transfer zone 40,
namely by an outlet channel 46, which extends from an outlet opening 48 in said Inner
wall 22 through said runner 20 to a hole (aperture) 47 within said outer wall 14a.
In this embodiment, the channel 46 extends in a slightly Inclined fashion downwards
between outlet opening 48 and hole 47 and two distinct outlet channels 46 are arranged
at a distance to each other and accordingly two outlet openings 48 and two holes 47
are provided.
[0057] The solids, leaving the heat exchanger zone 40 via this outlet opening 48 (arrow
O), are recycled into the combustor C.
[0058] The new heat exchanger urges the solids to make a kind of a loop, symbolized In Fig.
1 by arrow L.
[0059] It is within the scope of the invention to extract other parts of the solids separately,
for example by one or more further outlet openings in any of the outer walls 14b,c,d.
1. A fluidized bed heat exchanger, which comprises a runner (20), at least one inlet
opening (18), a heat exchange zone (40) and at least one outlet opening (48), arranged
to each other in a way to allow a stream of solids, deriving from an associated combustor
(C), to enter the heat exchanger (10) via said opening (18), to pass through said
heat exchange zone (40) and to leave the heat exchanger (10) via said outlet opening
(48), wherein
a) the Inlet opening (18) is arranged at an upper part of the runner (20),
b) the runner (20) extends downwardly from an upper section of the heat exchanger
towards a bottom-section (16r) of the heat exchanger (10) and ends close to said bottom-section
(16r), thereby allowing a downwardly oriented flow of the solids through said runner
(20),
c) the runner (20) is open at its end close to said bottom-section (16r), thereby
providing at least one passage (TR) for the solids to leave the runner (20) and to
flow into at least one heat exchange zone (40), which is arranged adjacent to said
runner (20) and provided with a fluidized bottom (16c), characterized in that,
d) the outlet opening (48) is arranged at an upper part of the heat exchanger (10)
and extends from the at least one heat exchange zone (40) as part of an outlet channel
(46), which outlet channel (46) extends from said heat exchange zone (40) through
said runner (20) to an aperture (47) in an outer wall (14a) of the heat exchanger
(10).
2. The heat exchanger of claim 1, wherein the outlet opening (48) is arranged at a lower
elevation than the Inlet opening (18).
3. The heat exchanger of claim 1, wherein an outer vertical wall (14a) of the heat exchanger
(10) constitutes an outer wall of the runner (20),
4. The heat exchanger of claim 1, wherein three outer vertical walls (14a,b,d) of the
heat exchanger (10) constitute three outer walls of the runner (20) and a fourth wall
of the runner (20) is provided by a partition wall (22), which extends between two
opposing outer vertical walls (14b, 14d) of the heat exchanger (10).
5. The heat exchanger of claim 1, wherein the heat exchange zone (40) comprises a number
of heat exchange tubes (42a-e), arranged at a distance to each other to provide chamber
like compartments (45) between adjacent heat exchange tubes (42a-e).
6. The heat exchanger of claim 5, wherein one or more of said heat exchange tubes (42a-e)
are arranged in a wall-like pattern.
7. The heat exchanger of claim 5, wherein one or more of said heat exchange tubes (42a-e)
are mounted in an outer wall (14c) of the heat exchanger (10).
8. The heat exchanger of claim 5, wherein one or more of said heat exchange tubes (42a-e)
are mounted in a discrete and detachable section (44) of a vertical outer wall (14c)
of the heat exchanger (10), which outer vertical wall (14c) extends opposite to the
outer wall (14a), which is part of the runner (20).
9. The heat exchanger of claim 1, wherein the runner (20) is free of any heat exchange
tubes.
10. The heat exchanger of claim 1, comprising a baffle (20b) at a downstream end of the
runner (20) to redirect the stream of solids from a predominantly vertical and downwardly
oriented direction within the runner (20) into a predominantly horizontal direction
when entering the heat exchange zone (40).
11. An incineration apparatus, comprising a fossil, fuel fired combustor (C) with at least
one outlet port at its upper end, wherein said outlet port allows a mixture of gas
and solids exhausted from said combustor (C) to flow into at least one associated
separator for separating said solids from said gas, means to transfer at least part
of said separated solids from said separator into at least one fluidized bed heat
exchanger (10) according to claim 1, wherein the outer wall (14a) of the heat exchanger
(10), through which the solids leave the heat exchanger (10), is a common wall with
an outer combustor-wall (CW) and a common wall (CW) with an outer wall of the runner
(20).
1. Wirbelschichtwärmetauscher, der einen Zugangsbereich (20), mindestens eine Einlassöffnung
(18), eine Wärmeaustauschzone (40) und mindestens eine Auslassöffnung (48) aufweist,
die so zueinander angeordnet sind, dass ein von einer zugeordneten Brennkammer (C)
stammender Feststoffstrom über die Öffnung (18) in den Wärmetauscher (10) eintritt,
die Wärmeaustauschzone (40) durchströmt und den Wärmetauscher (10) über die Auslassöffnung
(48) verlässt, wobei
a) die Einlassöffnung (18) an einem oberen Teil des Zugangsbereichs (20) angeordnet
ist,
b) der Zugangsbereich (20) sich von einem oberen Abschnitt des Wärmetauschers nach
unten zu einem Bodenabschnitt (16r) des Wärmetauschers (10) erstreckt und nahe dem
Bodenabschnitt (16r) endet, wobei eine nach unten gerichtete Strömung der Feststoffe
durch den Zugangsbereich (20) ermöglicht wird,
c) der Zugangsbereich (20) an seinem Ende nahe dem Bodenabschnitt (16r) offen ist,
wodurch mindestens ein Durchgang (TR) für die Feststoffe bereitgestellt wird, um den
Zugangsbereich (20) zu verlassen und in mindestens eine Wärmeaustauschzone (40) zu
fließen, die benachbart zum Zugangsbereich (20) angeordnet und mit einem durchströmbaren
Boden (16c) versehen ist,
dadurch gekennzeichnet, dass
d) die Auslassöffnung (48) an einem oberen Teil des Wärmetauschers (10) angeordnet
ist und sich von der mindestens einen Wärmeaustauschzone (40) als Teil eines Austrittskanals
(46) erstreckt, wobei sich der Austrittskanal (46) von der Wärmeaustauschzone (40)
durch den Zugangsbereich (20) zu einer Öffnung (47) in einer Außenwand (14a) des Wärmetauschers
(10) erstreckt.
2. Wärmetauscher nach Anspruch 1, bei dem die Auslassöffnung (48) unterhalb einer Ebene
der Einlassöffnung (18) verläuft.
3. Wärmetauscher nach Anspruch 1, bei dem eine äußere vertikale Wand (14a) des Wärmetauschers
(10) eine äußere Wand des Zugangsbereichs (20) bildet.
4. Wärmetauscher nach Anspruch 1, bei dem drei äußere vertikale Wände (14a,b,d) des Wärmetauschers
(10) drei äußere Wände des Zugangsbereichs (20) bilden und eine vierte Wand des Zugangsbereichs
(20) von einer Trennwand (22) gebildet wird, die sich zwischen zwei gegenüberliegenden
äußeren vertikalen Wänden (14b, 14d) des Wärmetauschers (10) erstreckt.
5. Wärmetauscher nach Anspruch 1, bei dem die Wärmeaustauschzone (40) eine Vielzahl von
Wärmetauschrohren (42a-e) umfasst, die mit Abstand zueinander angeordnet sind, um
kammerartige Räume (45) zwischen benachbarten Wärmetauschrohren (42a-e) zu bilden.
6. Wärmetauscher nach Anspruch 5, bei dem ein oder mehrere Wärmetauschrohre (42a-e) in
einer wandartigen Anordnung konfektioniert sind.
7. Wärmetauscher nach Anspruch 5, bei dem ein oder mehrere Wärmetauschrohre (42a-e) in
einer äußeren Wand (14c) des Wärmetauschers (10) befestigt sind.
8. Wärmetauscher nach Anspruch 5, bei dem ein oder mehrere Wärmetauschrohre (42a-e) in
einem diskreten und abnehmbaren Abschnitt (44) einer vertikalen äußeren Wand (14c)
des Wärmetauschers (10) befestigt sind, wobei die vertikale äußere Wand (14c) sich
gegenüber der Wand (14a) erstreckt, die Teil des Zugangsbereichs (20) ist.
9. Wärmetauscher nach Anspruch 1, bei dem der Zugangsbereich (20) frei von Wärmetauschrohren
ist.
10. Wärmetauscher nach Anspruch 1 mit einem Umlenkelement (20b) an einem stromabwärts
gelegenen Ende des Zugangsbereichs (20), um den Feststoffstrom von einer im wesentlichen
vertikalen und nach unten gerichteten Strömungsrichtung im Zugangsbereich (20) in
eine im wesentlichen horizontale Richtung beim Eintritt in die Wärmetauschzone (40)
umzulenken.
11. Verbrennungsvorrichtung mit einer mit fossilem Brennstoff befeuerten Brennkammer (C)
mit mindestens einer Auslaßöffnung an ihrem oberen Ende, wobei die Auslaßöffnung eine
Mischung aus Gas und Feststoffen, die von der Brennkammer (C) abgesaugt werden, in
mindestens einen zugehörigen Separator zum Abtrennen der Feststoffe von dem Gas fließen
läßt, Mitteln zum Überführen wenigstens eines Teils der abgetrennten Feststoffe aus
dem Separator in wenigstens einen Wirbelschichtwärmetauscher (10) nach Anspruch 1,
wobei die Außenwand (14a) des Wärmetauschers (10), durch die die Feststoffe den Wärmetauscher
(10) verlassen, eine gemeinsame Wand mit einer äußeren Brennkammerwand (CW) und eine
gemeinsame Wand (CW) mit einer Außenwand des Zugangsbereichs (20) ist.
1. Échangeur thermique à lit fluidisé que comprend un passage (20), au moins une ouverture
d'entrée (18), une zone d'échange thermique (40) et au moins une ouverture de sortie
(48), agencés les uns par rapport aux autres de façon à permettre à un flux de solides,
dérivant d'une chambre de combustion (C) associée, de pénétrer dans l'échangeur thermique
(10) par le biais de ladite ouverture (18), de passer à travers ladite zone d'échange
thermique (40) et de quitter l'échangeur thermique (10) par le biais de ladite ouverture
d'entrée (48), dans lequel
a) l'ouverture d'entrée (18) est agencée sur une partie supérieure du passage (20),
b) le passage (20) s'étend vers le bas depuis une section supérieure de l'échangeur
thermique en direction d'une section inférieure (16r) de l'échangeur thermique (10)
et finit près de ladite section inférieure (16r), permettant ainsi un flux orienté
vers le bas des solides à travers ledit passage (20),
c) le passage (20) est ouvert à son extrémité proche de ladite section inférieure
(16r), fournissant ainsi au moins un passage (TR) pour que les solides quittent le
passage (20) et circulent jusque dans au moins une zone d'échange thermique (40) qui
est agencée adjacente audit passage (20) et dotée d'un fond fluidisé (16c),
caractérisé en ce que
d) l'ouverture de sortie (48) est agencée sur une partie supérieure de l'échangeur
thermique (10) et s'étend à partir de l'au moins une zone d'échange thermique (40)
en tant que partie d'un canal de sortie (46), lequel canal de sortie (46) s'étend
depuis ladite zone d'échange thermique (40) à travers ledit passage (20) vers une
percée (47) dans une paroi extérieure (14a) de l'échangeur thermique (10).
2. Échangeur thermique selon la revendication 1, dans lequel l'ouverture de sortie (48)
est agencée à une élévation inférieure à l'ouverture d'entrée (18).
3. Échangeur thermique selon la revendication 1, dans lequel une paroi verticale extérieure
(14a) de l'échangeur thermique (10) constitue une paroi extérieure du passage (20).
4. Échangeur thermique selon la revendication 1, dans lequel trois parois verticales
extérieures (14a, b, d) de l'échangeur thermique (10) constituent trois parois extérieures
du passage (20) et une quatrième paroi du passage (20) est fournie par une cloison
de séparation (22) qui s'étend entre deux parois verticales extérieures opposées (14b,
14d) de l'échangeur thermique (10).
5. Échangeur thermique selon la revendication 1, dans lequel la zone d'échange thermique
(40) comprend un nombre de tubes d'échange thermique (42a-e), agencés à une distance
l'un de l'autre pour fournir des compartiments (45) semblables à des chambres entre
des tubes d'échange thermique (42a-e) adjacents.
6. Échangeur thermique selon la revendication 5, dans lequel un ou plusieurs desdits
tubes d'échange thermique (42a-e) sont agencés dans un schéma semblable à une paroi.
7. Échangeur thermique selon la revendication 5, dans lequel un ou plusieurs desdits
tubes d'échange thermique (42a-e) sont montés dans une paroi extérieure (14c) de l'échangeur
thermique (10).
8. Échangeur thermique selon la revendication 5, dans lequel un ou plusieurs desdits
tubes d'échange thermique (42a-e) sont montés dans une section discrète et séparable
(44) d'une paroi extérieure verticale (14c) de l'échangeur thermique (10), laquelle
paroi verticale extérieure (14c) s'étend à l'opposé de la paroi extérieure (14a) qui
fait partie du passage (20).
9. Échangeur thermique selon la revendication 1, dans lequel le passage (20) est exempt
de tout tube d'échange thermique.
10. Échangeur thermique selon la revendication 1, comprenant un déflecteur (20b) à une
extrémité en aval du passage (20) pour rediriger le flux de solides d'une direction
principalement orientée verticalement et vers le bas à l'intérieur du passage (20)
dans une direction principalement horizontale lorsqu'il pénètre la zone d'échange
thermique (40).
11. Appareil d'incinération, comprenant une chambre de combustion fossile fonctionnant
au carburant (C) comprenant au moins un port de sortie sur son extrémité supérieure,
dans lequel ledit port de sortie permet à un mélange de gaz et de solides évacué de
ladite chambre de combustion (C) de circuler jusque dans au moins un séparateur associé
pour séparer lesdits solides desdits gaz, un moyen pour transférer au moins une partie
desdits solides séparés dudit séparateur jusqu'à au moins un échangeur thermique à
lit fluidisé (10) selon la revendication 1, dans lequel la paroi extérieure (14a)
de l'échangeur thermique (10), par laquelle les solides quittent l'échangeur thermique
(10) est une paroi commune avec une paroi de chambre de combustion extérieure (CW)
et une paroi commune (CW) avec une paroi extérieure du passage (20).