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EP 0 811 143 B1 |
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EUROPEAN PATENT SPECIFICATION |
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Mention of the grant of the patent: |
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24.11.1999 Bulletin 1999/47 |
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Date of filing: 21.02.1996 |
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International Patent Classification (IPC)6: F28D 19/04 |
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International application number: |
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PCT/SE9600/232 |
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International publication number: |
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WO 9626/407 (29.08.1996 Gazette 1996/39) |
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ROTARY REGENERATIVE HEAT EXCHANGER AND A METHOD FOR OPERATING SUCH HEAT EXCHANGER
UMLAUFENDER REGENERATIVER WÄRMETAUSCHER UND VERFAHREN ZUM BETREIBEN EINES UMLAUFENDES
REGENERATIVES WÄRMETAUSCHERS
ECHANGEUR DE CHALEUR ROTATIF A REGENERATION ET SON MODE D'UTILISATION
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Designated Contracting States: |
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DE DK FR GB SE |
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Priority: |
24.02.1995 SE 9500681
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Date of publication of application: |
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10.12.1997 Bulletin 1997/50 |
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Proprietor: ABB AIR PREHEATER, INC. |
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Wellsville, NY 14895-0372 (US) |
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Inventor: |
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- WESTERLUND, Dag
S-175 73 Järfälla (SE)
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Representative: Waldinger, Ake |
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Svenska Rotor Maskiner AB
Box 15085 104 65 Stockholm 104 65 Stockholm (SE) |
(56) |
References cited: :
WO-A-93/19339 WO-A-95/01541 SE-A- 9 302 301 US-A- 3 232 335
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WO-A-94/01730 DE-C- 973 548 US-A- 3 122 200 US-A- 3 499 480
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- PATENT ABSTRACTS OF JAPAN, Vol. 5, No. 83, M-71; & JP,A,56 030 588 (NISSAN JIDOSHA
K.K.), 27 March 1981.
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Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
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[0001] The present invention in a first aspect relates to a rotary regenerative heat exchanger
of the kind specified in the preamble of claim 1 and in a second aspect to a method
for operating such heat exchanger as specified in the preamble of claim 8.
[0002] SE 176 375 discloses a rotary regenerative heat exchanger with a support in the form
of rolling bodies, mounted in the outer ends of sector-shaped plates closed to both
ends of the rotating part and rolling on a flange along the periphery at the top and
bottom end of the rotor.
[0003] It was therethrough intended that a constant clearance should be possible to be maintained
between the ends of the sector-shaped plates and the top and bottom end, respectively.
The environment for the rollers, however, was found to be to severe. The bearings
of the rollers were worn out rapidly and dirt and particles were by the rolling adhered
on the flanges and the surfaces of the roller with break downs as a consequence.
[0004] It has been suggested to replace the rollers by sliding shoes as disclosed in JP,
A, 63-315 891. These sliding shoes are made of ceramics in order to attain a high
wear resistance. However, problems will occur if the sliding shoe becomes somewhat
slanting due to mounting inaccuracy and/or thermal deformations. There will in such
cases be a risk that the sliding shoe will contact the flange by only a small part
of its sliding surface with unacceptable high contact pressure as a consequence. Furthermore
some kind of external lubrication of the sliding surfaces is required or considerable
friction losses has to be accepted.
[0005] In WO94/01730 an improvement is disclosed by using sliding shoes of carbon or graphite
instead of ceramic sliding shoes. Such a sliding shoe eliminates the drawbacks with
a sliding shoe of ceramics. In particular graphite has excellent lubrication properties
and like carbon has an ability to maintain the flanges of the rotating body clean
when adhering a lubricating layer of carbon or graphite on the flanges. The abrasion
of the sliding shoe also secures a correct contact with parallel contact surfaces
so that the contact takes place on the complete sliding shoe surface. Carbon and graphite
also have a good acceptance of the high temperature and the acid environment that
are present. By the abrasion of the sliding shoes they will gradually be consumed
and have to be replaced. The degree of abrasion, however, will vary widely, so that
one or more sliding shoes might be worn down so much that the clearance reaches zero,
whereas other sliding shoes will be almost unaffected. Each sliding shoe therefore
is adjustable in a direction perpendicular to the contact surface. A similar solution
is disclosed in WO95/00809, in which there is provided a measuring rod adjacent to
the sliding shoe, which measuring rod is directed parallel to the adjustment direction.
The measuring rod from a resting position can be momentary brought in contact with
the related flange and indicates when the size of the clearance requires advancement
of the sliding shoe a distance so that the initial clearance is restored.
[0006] Another solution is disclosed in SE 9302301-8 in which the abrasion problems are
overcome in that the sliding shoe is sliding on a gas cushion created by the supply
of pressure gas between the sliding shoe and a flange on the rotor. Abrasion thereby
is avoided in that there will be no contact between the sliding shoe and the flange.
A further heat exchanger where a sliding shoe is sliding on a gas cushion is known
by WO-A-9 501 541.
[0007] Arrangement of the sliding shoes hovering on air cushions, however, increases the
costs. Each shoe will be more sophisticated and thereby circumstantial to manufacture,
and gas piping has to be connected to each individual sliding shoe.
[0008] Common to all the above discussed arrangements of the supports, the contacting as
well as the contact-fee types, is that at least two individual supports are provided
for each sector plate.
[0009] The reason for that is to secure a steady supporting of the sector plate and avoid
tilting thereof. One single support at the middle of the outer periphery of the plate
should theoretically be enough since the plate at its inner end is supported by two
pivot connections to the fixed centre plate. Due to flexibility of the movable sector
plate and/or thermal deformation there will in practice, however, be a risk for the
outer edges of the plate to tilt and hit against the rotor, when there is only one
support.
[0010] However, when using the contact-free type of sliding shoe, which is more expensive
than the traditional type, there is a desire to reduce the number of such sliding
shoes.
[0011] The object of the present invention therefore is to attain a regenerative heat exchanger
of the kind in question in which the number of sliding shoes is as small as possible.
[0012] This has according to the present invention been achieved in that a rotary regenerative
heat exchanger of the kind specified in the preamble of claim 1 has got the features
specified in the characterizing portion of that claim and in another aspect in that
a method as specified in the preamble of claim 8 includes the measures specified in
the characterizing portion of that claim.
[0013] The device according to the invention thus deviates from the traditional concept
of using two or more supports for the sector plate, when supports of the non-contacting
type are used. The problem of avoiding tilting is overcome in that the support is
elongated so that the outer part of the sector plate is stabilized in the circumferential
direction.
[0014] By using only one contact-free support for each sector plate the number of devices
for establishing gas cushions is reduced to the half, which lowers the manufacturing
and maintenance costs and reduces the risk for failure. Due to the elongated shape,
the air cushion will have a larger circumferential extension, and the area of the
air cushion can be increased. Thereby a sufficient raising force from the air cushion
can be attained at a lower pressure of the supplied gas in comparison with a conventional
pair of circular air cushions. Since the requirement on the pressure level of the
gas source thus will be lower, the running costs for the gas supply is reduced.
[0015] The angular extension of the front surface preferably is more than half the angular
extension of the sector plate in order to attain a sufficiently stabilized support
by the air cushion and it should preferably be symmetrically located.
[0016] Preferably the gas outlet has a corresponding elongated shape, whereby a uniform
distribution of the gas is promoted.
[0017] These and other advantageous embodiments are specified in the dependent claims.
[0018] The invention will be further explained through the following detailed description
of a preferred embodiment thereof and with reference to the accompanying drawings,
of which
fig. 1 is a partial axial section through a first preferred embodiment of the invention,
fig. 2 is a view taken along line II-II of fig. 1,
fig. 3 is a view similar to that of fig. 2, illustrating a second embodiment of the
invention,
fig. 4 is a view similar to that of fig. 2, illustrating a third embodiment of the
invention,
fig. 5 is a schematic section along line V-V of fig. 2, and
fig. 6 is a view similar to that of fig. 5, illustrating a fourth embodiment of the
invention.
[0019] The heat exchanger illustrated in fig. 1 is of conventional type having a stationary
casing 1 and a cylindrical rotor 2 containing the regenerative mass 3. The rotor has
a hub 4 and an upper fixed sector shaped centre plate 5 with a movable sector plate
6 pivotally connected thereto and corresponding lower fixed centre plate 7 and movable
sector plate 8. The two sets of plates 5, 6 and 7, 8 have the function to seal against
the upper and lower ends of the rotor 2 as tight as possible and thereby separate
the heat exchanging media flowing to and from the rotor through axial openings connected
to media ducts (not shown).
[0020] For that purpose the radially outer ends of each of the movable sector plates 6,
8 are provided a device, which device forms support means 10 for maintaining a certain
clearances between the ends of the sector plates 6, 8 and an upper and lower annular
edge flange 12 attached to the rotor along its upper and lower peripheries, each flange
having an outer circumferentially continuous end surface 61 for co-operation with
a front surface 62 connected to each of the devices 10.
[0021] In fig. 2 the sector plate 6 is seen from the outside and co-operates with the end
surface 11 of the rotor end flange 9. Through a sleeve 15 pressure gas is supplied
to a sliding shoe forming gas cushion means with a front surface facing the end surface
11 of the flange 9. The front surface 12 of the sliding shoe is arc-shaped and limited
by two concentric circular arcs 14 and 15. The sliding shoe is symmetrically arranged
in relation to a symmetry line 19 of the sector plate 6 and extends along the flange
9 about two thirds of the angular extension of the sector plate. The gas supplied
through the sleeve 15 is distributed through channels in the sliding shoe to an arc-shaped
groove 16 in the front surface 12 of the sliding shoe, and creates an air cushion
between the front surface 12 of the sliding shoe and the end surface 11 of the flange
9. Although only one gas cushion supports the sector plate 6 the support will be stable
and without risk for tilting due to the elongated shape of the gas cushion.
[0022] Fig. 3 illustrates the support 10 through a section therethrough. The arc-shaped
sliding shoe 17 is rigidly attached to the sector plate 6 and projects a short distance
from the internal surface 28 of the sector plate 6.
[0023] In the front surface 12 of the sliding shoe 17 the groove 16 forming the gas outlet
means extends along almost the entire length of the front surface. Through a plurality
of channels 27 the groove 16 communicates with the opposite side of the sliding shoe.
This side is covered by a closure member 18 of the same shape as the sliding shoe
17. The closure member has a gas inlet opening 25 and a distribution groove 26 through
which the inlet opening 25 and the channels 27 communicate. A circular sleeve 15 is
attached to the closure member 18 around the gas inlet opening 25, which sleeve extends
out through a circular hole in the casing 1, and the opposite end of the sleeve 15
is through a gas conduit 23 connected to a pressure gas source 22. Between a flange
20 attached to the sleeve 15 and the casing 1 a sealing bellow 21 is provided, so
that a predetermined axial force will be applied downwards on the plate 6 due to the
spring effect of the bellow 21.
[0024] In operation pressure gas flows through conduit 23, the interior 24 of the sleeve
15, the inlet opening 25, the distribution groove 26 and the channels 27 to the groove
16. The pressure of the gas keeps the front surface 12 of the sliding shoe 17 raised
from the end surface 11 of the flange 9 against the action of the force from the bellow
21, so that the gas is allowed to escape through these surfaces, thereby creating
the elongated air cushion.
[0025] Fig. 6 illustrates an alternative embodiment of the support 10, in which the front
surface 12"' co-operating with the end surface 11 of the flange 9 is formed by a part
of the inner surface 28 of the sector plate 6. The clearance S between the sector
plate 6 and the end flange thereby will be more narrow. In order to avoid contact
between the plate 6 and the flange the groove 12' extends circumferentially almost
to the ends of the sector plate so that the air cushion will receive a corresponding
extension.
[0026] Figs. 3 and 4 illustrate alternative shapes ofthe front surface 12', 12", respectively.
In fig. 3 the front surface 12' is rectangular, limited by two straight lines 13',
14', and in fig. 4 the front surface is crescent-shaped, limited by two non-concentric
circular arcs 13", 14".
1. Rotary regenerative heat exchanger having a substantially cylindrical rotor (2) mounted
in a casing (1), which rotor (2) at at least one of its ends is provided with a circumferentially
continuous external end surface (11), and which casing (1) is provided with plates
(5, 6, 7, 8) at at least one of said rotor ends in an orientation substantially perpendicular
to the axis of said rotor (2) and closed to the related rotor end, said plates (5,
6, 7, 8) including movable sector plates (6, 8), each said sector plate (6, 8) being
affected by a resultant axial force towards the related rotor end and being provided
with support means (10) for maintaining a certain clearance (S) between said sector
plates (6, 8) and the related rotor end, said support means (10) including gas cushion
means (17), each said gas cushion means (17) having a front surface (12) facing said
end surface (11), said front surface (12) having gas outlet means (16), said gas outlet
means communicating through gas conduit means (23, 24, 25, 26, 27) with a pressurized
gas source (22) of a pressure sufficient to establish a gap between said front surface
(12) and said end surface (11) against the action of said axial force, thereby creating
a gas cushion between said front surface (12) and said end surface (11) as said gas
escapes from said gas outlet means (16) through said gap, characterized in that the
support means (10) of at least one of said sector plates (6, 8) consists of one single
gas cushion means (17) and that the front surface (12) of said gas cushion means has
an elongated shape, having its longer extension directed circumferentially along said
end surface (11).
2. Rotary regenerative heat exchanger according to claim 1, wherein said front surface
(12) is radially limited by two concentric circular arcs (13, 14) and having substantially
a sausage-shape.
3. Rotary regenerative heat exchanger according to claim 1, wherein said front surface
(12') is radially limited by two parallel straight lines (13', 14'), and having a
substantially rectangular shape.
4. Rotary regenerative heat exchanger according to claim 1, wherein said front surface
(12") is radially limited by two non-concentric circular arcs (13", 14") and having
substantially a crescent-shape.
5. Rotary regenerative heat exchanger according to any of claims 1 to 4, wherein the
angular extension of said front surface (12) is more than half the angular extension
of said sector plate (6, 8), and said front surface (12) is symmetrically located
relative to a radial symmetry (19) line in the plane of said sector plate (6, 8).
6. Rotary regenerative heat exchanger according to any of claims 1 to 5, wherein said
gas outlet means (16) is a groove extending in the longitudinal direction of said
front surface (12).
7. Rotary regenerative heat exchanger according to claim 1 or 2, wherein said front surface
(12'") is a part of the internal surface (28) of said sector plate (6, 8).
8. A method for operating a rotary regenerative heat exchanger to maintain a certain
clearance (S) between one end of a substantially cylindrical rotor (2) of the heat
exchanger and a movable sector plate (6, 8) located closed to said rotor end in an
orientation substantially perpendicular to the axis of said rotor (2), said rotor
end having a circumferentially continuous end surface (11), said rotor (2) being mounted
in a casing (1) and said sector plate (6, 8) being connected to said casing and being
affected by a resultant axial force towards said rotor end, said clearance (S) being
maintained by supplying gas to support means (10) on said sector plate (6, 8) said
support means (10) including gas cushion means (17) having a front surface (12) with
gas outlet means (16) and facing said end surface (11), the pressure of said supplied
gas being sufficient to establish a gap between said front surface (12) and said end
surface (11) against the action of said axial force, thereby creating a gas cushion
between said front surface (12) and said end surface (11) as said gas escapes from
said gas outlet means (16) through said gap, characterized by supplying said gas to
one single support means (10) and arranging said single support means (10) to form
an elongated gas cushion, having its longer extension directed circumferentially along
said end surface (11).
1. Rotierender, regenerativer Wärmetauscher mit einem im wesentlichen zylindrischen Rotor
(2), der in einem Gehäuse (1) montiert ist und an wenigstens einem seiner Enden mit
einer über den Umfang durchgängigen äußeren Endfläche(11) versehen ist, wobei das
Gehäuse (1) an wenigstens einem der Rotorenden mit Platten (5, 6, 7, 8) mit im wesentlichen
senkrecht zur Achse des Rotors (2) liegender Ausrichtung nahe des zugehörigen Rotorendes
versehen ist, die bewegliche Sektorplatten (6, 8) aufweisen, die durch eine resultierende
Axialkraft in Richtung des zugehörigen Rotorendes beaufschlagt und zur Aufrechterhaltung
eines bestimmten Spiels (S) zwischen den Sektorplatten (6, 8) und dem zugehörigen
Rotorende mit Stützmitteln (1C) versehen sind, die Gaskissenmittel (17) aufweisen,
die jeweils eine Frontfläche (12) besitzen, die der Endfläche (11) zugewandt ist und
Gasauslaßmittel (16) aufweist, die durch Gasleitungsmittel (23, 24, 25, 26, 27) mit
einer Druckgasquelle (22) mit einem Druck in Verbindung stehen, der ausreichend ist,
um einen Spalt zwischen der Frontfläche (12) und der Endfläche (11) gegen die Wirkung
der Axialkraft aufzubauen, wodurch ein Gaskissen zwischen der Frontfläche (12) und
der Endfläche (11) entsteht, da das Gas aus den Gasauslaßmitteln (16) durch den Spalt
austritt, dadurch gekennzeichnet, daß die Stützmittel (10) wenigstens einer der Sektorplatten (6, 8) aus einzelnen,
alleinigen Gaskissenmitteln (17) bestehen und daß die Frontfläche (12) der Gaskissenmittel
eine Langform besitzt, deren längere Erstreckung über den Umfang entlang der Endfläche
(11) ausgerichtet ist.
2. Rotierender, regenerativer Wärmetauscher nach Anspruch 1, dadurch gekennzeichnet, daß die Frontfläche (12) durch zwei konzentrische Kreisbögen (13, 14) radial begrenzt
ist und im wesentlichen eine Wurstform besitzt.
3. Rotierender, regenerativer Wärmetauscher nach Anspruch 1, dadurch gekennzeichnet, daß die Frontfläche (12') radial durch zwei parallele, gerade Kanten (13', 14') begrenzt
ist und eine im wesentlichen rechteckige Form besitzt.
4. Rotierender, regenerativer Wärmetauscher nach Anspruch 1, dadurch gekennzeichnet, daß die Frontfläche (12") radial durch zwei nicht konzentrische Kreisbögen (13",
14") begrenzt ist und im wesentlichen eine Sichelform besitzt.
5. Rotierender, regenerativer Wärmetauscher nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, daß die Winkelerstreckung der Frontfläche (12) mehr als die Hälfte der Winkelerstreckung
der Sektorplatte (6, 8) beträgt und die Frontfläche (12) symmetrisch mit Bezug auf
eine radiale Symmetrielinie (19) in der Fläche der Sektorplatte (6, 8) angeordnet
ist.
6. Rotierender, regenerativer Wärmetauscher nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß die Gasauslaßmittel (16) aus einer Nut bestehen, die sich in der Längsrichtung
der Frontfläche (12) erstreckt.
7. Rotierender, regenerativer Wärmetauscher nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß die Frontfläche (12"') ein Teil einer inneren Fläche (28) der Sektorplatte (6,
8) ist.
8. Verfahren zum Betreiben eines rotierenden, regenerativen Wärmetauschers, um ein bestimmtes
Spiel (S) zwischen einem Ende eines im wesentlichen zylindrischen Rotors (2) des Wärmetauschers
und einer nahe des Rotors angeordneten beweglichen Sektorplatte (6, 8) in einer Richtung
im wesentlichen senkrecht zur Achse des Rotors (2) aufrechtzuerhalten, wobei das Rotorende
eine über den Umfang durchgängige äußere Endfläche (11) besitzt, der Rotor (2) in
einem Gehäuse (1) montiert ist, die Sektorplatte (6, 8) mit dem Gehäuse verbunden
und durch eine resultierende Axialkraft in Richtung des Rotorendes beaufschlagt ist,
und das Spiel (S) durch Zuführen von Gas zu an der Sektorplatte (6, 8) befindlichen
Stützmitteln (10) aufrechterhalten wird, die Gaskissenmittel (17) mit einer der Endfläche
(11) zugewandten Frontfläche (12) mit Gasauslaßmitteln (16) aufweist, wobei der Druck
des zugeführten Gases ausreichend ist, einen Spalt zwischen der Frontfläche (12) und
der Endfläche (11) gegen die Wirkung der Axialkraft aufzubauen, wodurch ein Gaskissen
zwischen der Frontfläche (12) und der Endfläche (11) erzeugt wird, da das Gas von
den Gasauslaßmitteln (16) durch den Spalt ausströmt, dadurch gekennzeichnet, daß das Gas einzelnen, alleinigen Stützmitteln (10) zugeführt wird und diese einzelnen
Stützmittel (10) so angeordnet werden, daß sie ein langförmiges Gaskissen bilden,
dessen längere Erstreckung über den Umfang entlang der Endfläche (11) ausgerichtet
ist.
1. Echangeur de chaleur rotatif à régénération comportant un rotor essentiellement cylindrique
(2) monté dans une enveloppe (1), lequel rotor (2) à au moins l'une de ses extrémités,
est muni d'une surface d'extrémité externe continue suivant la circonférence (11),
et laquelle enveloppe (1) est munie de plaques (5, 6, 7, 8) à au moins une desdites
extrémités du rotor suivant une orientation pratiquement perpendiculaire à l'axe dudit
rotor (2) et rapprochée de l'extrémité de rotor associée, lesdites plaques (5, 6,
7, 8) comprenant des plaques en secteur mobiles (6, 8), chaque dite plaque en secteur
(6, 8) étant affectée par une force axiale résultante en direction de l'extrémité
de rotor associée et étant munie d'un moyen de support (10) afin de conserver un certain
espacement (S) entre lesdites plaques en secteur (6, 8) et l'extrémité de rotor associée,
ledit moyen de support (10) comprenant un moyen de coussin de gaz (17), chaque dit
moyen de coussin de gaz (17) présentant une surface avant (12) en regard de ladite
surface d'extrémité (11), ladite surface avant (12) comprenant un moyen de sortie
de gaz (16), ledit moyen de sortie de gaz communiquant par l'intermédiaire d'un moyen
de conduite de gaz (23, 24, 25, 26, 27) avec une source de gaz sous pression (22)
d'une pression suffisante pour établir un interstice entre ladite surface avant (12)
et la surface d'extrémité (11) en s'opposant à l'action de ladite force axiale, en
créant ainsi un coussin de gaz entre ladite surface avant (12) et ladite surface d'extrémité
(11) lorsque ledit gaz s'échappe dudit moyen de sortie de gaz (16) par l'intermédiaire
dudit interstice, caractérisé en ce que le moyen de support (10) d'au moins l'une
desdites plaques en secteur (6, 8) est constitué d'un seul moyen de coussin de gaz
(17) et en ce que la surface avant (12) dudit moyen de coussin de gaz présente une
forme allongée, présentant son étendue plus longue orientée suivant la circonférence
le long de ladite surface d'extrémité (11).
2. Echangeur de chaleur rotatif à régénération selon la revendication 1, dans lequel
ladite surface avant (12) est limitée radialement par deux arcs de cercle concentriques
(13, 14) et présente essentiellement la forme d'une saucisse.
3. Echangeur de chaleur rotatif à régénération selon la revendication 1, dans lequel
ladite surface avant (12') est limitée radialement par deux lignes droites parallèles
(13', 14'), et présente une forme essentiellement rectangulaire.
4. Echangeur de chaleur rotatif à régénération selon la revendication 1, dans lequel
ladite surface avant (12") est limitée radialement par deux arcs de cercle non concentriques
(13", 14") et présente essentiellement la forme d'un croissant.
5. Echangeur de chaleur rotatif à régénération selon l'une quelconque des revendications
1 à 4, dans lequel l'étendue angulaire de ladite surface avant (12) est supérieure
à la moitié de l'étendue angulaire de ladite plaque en secteur (6, 8), et ladite surface
avant (12) est située de façon symétrique relativement à une ligne de symétrie radiale
(19) dans le plan de ladite plaque en secteur (6, 8).
6. Echangeur de chaleur rotatif à régénération selon l'une quelconque des revendications
1 à 5, dans lequel ledit moyen de sortie de gaz (16) est une gorge s'étendant suivant
la direction longitudinale de ladite surface avant (12).
7. Echangeur de chaleur rotatif à régénération selon la revendication 1 ou 2, dans lequel
ladite surface avant (12"') fait partie de la surface interne (28) de ladite plaque
en secteur (6, 8).
8. Procédé de mise en oeuvre d'un échangeur de chaleur rotatif à régénération de façon
à conserver un certain espacement (S) entre une extrémité d'un rotor pratiquement
cylindrique (2) de l'échangeur de chaleur et une plaque en secteur mobile (6, 8) située
près de ladite extrémité de rotor suivant une orientation essentiellement perpendiculaire
à l'axe dudit rotor (2), ladite extrémité de rotor présentant une surface d'extrémité
continue suivant la circonférence (11), ledit rotor (2) étant monté dans une enveloppe
(1) et ladite plaque en secteur (6, 8) étant reliée à ladite enveloppe et étant affectée
par une force axiale résultante en direction de ladite extrémité de rotor, ledit espacement
(S) étant conservé en alimentant un gaz vers un moyen de support (10) sur ladite plaque
en secteur (6, 8), ledit moyen de support (10) comprenant un moyen de coussin de gaz
(17) présentant une surface avant (12) comportant un moyen de sortie de gaz (16) et
en regard de ladite surface d'extrémité (11), la pression dudit gaz alimenté étant
suffisante pour établir un interstice entre ladite surface avant (12) et la surface
d'extrémité (11) en s'opposant à l'action de ladite force axiale, en créant ainsi
un coussin de gaz entre ladite surface avant (12) et ladite surface d'extrémité (11)
lorsque ledit gaz s'échappe depuis ledit moyen de sortie de gaz (16) par l'intermédiaire
dudit interstice, caractérisé par l'alimentation dudit gaz vers un unique moyen de
support (10) et l'agencement dudit unique moyen de support (10) de façon à former
un coussin de gaz allongé, dont l'étendue la plus longue est orientée suivant la circonférence
le long de ladite surface d'extrémité (11).