Note: Descriptions are shown in the official language in which they were submitted.
CA 02342425 2004-08-16
30177-1
MULTIPLE TUBE BUNDLE HEAT EXCHANGER
Background of the Invention:
Field of the Invention:
The invention relates to a multiple tube bundle
heat exchanger. In other words, the invention relates to a
heat exchanger configuration that includes a plurality of
flow-interconnected heat exchange tube bundles. The flow
interconnection may relate either to the medium flowing
through the tube bundles or to the medium flowing around the
tube bundles, or to both.
Multiple tube bundle heat exchangers are already
in the prior art. For example, Switzerland Patent
No. CH 586 882 describes a counter-current tube bundle heat
exchanger in the form of an in-series, tube bundle heat
exchanger. In that heat exchanger, a common housing has
disposed in it a plurality of tube bundles that are flow-
connected in series and through which the primary medium
flows in succession. All the tube bundles run between two
tube sheets common to all the tube bundles, and the plenum
chambers above each of the tube sheets are subdivided into
partial chambers to form an inflow distributor chamber for
the primary medium for distribution to the tubes of the
first tube bundle, then a series of connecting chambers,
disposed above the one tube sheet or the other, for
connecting respectively the outlet ends of the tube bundle
to the inlet ends of an adjacent tube bundle, and, finally,
an outlet collecting chamber above the outlet ends of the
last tube bundle in the flow series connection. Between the
individual tube bundles are disposed, in the housing,
partitions that respectively have fluid transfer orifices
-1-
CA 02342425 2004-08-16
30177-1
near one tube sheet or the other so that the secondary
medium flows first into a first tube bundle chamber and then
passes through the fluid transfer orifices from tube bundle
chamber to tube bundle chamber and finally out of the last
tube bundle chamber into an outlet.
Summarv of the Invention:
It is accordingly an object of the invention to
provide a multiple tube bundle heat exchanger that overcomes
the hereinafore-mentioned disadvantages of the heretofore-
known devices of this general type and that provides a
configuration making it possible, on a modular basis, to
construct economically the most diverse tube bundle heat
exchanger configuration that is variable to the greatest
possible extent both in terms of size and in terms of the
flow configuration or of the routing of the primary medium
and secondary medium.
With the foregoing and other objects in view,
there is provided a multiple tube bundle heat exchanger,
comprising: a number of tube bundles, each of said tube
bundles being formed as a self-contained integral unit
having: two axially spaced tube sheets; and a plurality of
heat exchanger tubes each with opposite axial ends, said two
tube sheets mounted at said opposite axial ends of said heat
exchanger tubes; a casing having: a tubular portion
substantially coextending with said tube bundles and having:
an interior subdivided by partitions into a plurality of
axial chambers, a number of said axial chambers
corresponding to said number of said tube bundles, each of
said chambers receiving one of said tube bundles; two
opposite axial ends; and flanges disposed at said two
-2-
CA 02342425 2004-08-16
30177-1
opposite axial ends; and head pieces removably mounted to
said flanges, each of said head pieces having walls defining
at least a first wall portion of a plenum chamber; and said
two tube sheets of each of said tube bundles respectively
sealing an adjacent one of said head pieces and forming at
least a second wall portion of a respective plenum chamber
of said adjacent one head piece.
The concept according to the invention provides
for using standard heat exchanger tube bundles together with
standard housing sub-assemblies that allow a multiplicity of
combination possibilities and, of course, also heat
exchanger configurations of different size.
Other features that are considered as
characteristic for the invention are set forth in the
appended claims.
Although the invention is illustrated and
described herein as embodied in a multiple tube bundle heat
exchanger, it is, nevertheless, not intended to be limited
to the details shown because various modifications and
structural changes may be made therein without departing
from the spirit of the invention.
The construction and method of operation of the
invention, however, together with additional objects and
advantages thereof, will be best understood from the
following description of specific embodiments when read in
connection with the accompanying drawings.
Brief Description of the Drawinas:
Fig. 1 is a cross-sectional view of a counter-
current heat exchanger according to the invention
-3-
CA 02342425 2004-08-16
30177-1
constructed from a multiple configuration of tube bundles
and having a parallel flow connection of the tube bundles;
Fig. 2 is a cross-sectional view of an alternative
embodiment of the counter-current heat exchanger of Fig. 1
with a plurality of tube bundles, flow-connected in series;
Fig. 3 is a cross-sectional view of an alternative
embodiment of the counter-current heat exchanger of Fig. 1
with a plurality of tube bundles, flow-connected in
parallel, and with an alternative housing configuration; and
Fig. 4 is a cross-sectional view of an alternative
embodiment of the counter-current heat exchanger of Fig. 3
with a plurality of tube bundles, flow-connected in series,
and with a housing configuration developed in relation to
the configuration according to Fig. 2.
Description of the Preferred Embodiments:
In all the figures of the drawing, sub-features
and integral parts that correspond to one another bear the
same reference symbol in each case.
Referring now to the figures of the drawings in
detail and first, particularly to Fig. 1 thereof, there is
shown a heat exchanger having a casing and a plurality of
tube bundles disposed therein.
The casing is made of a tubular casing portion 1,
on which are disposed an inlet connection piece 11 and an
outlet connection piece 12 respectively introducing and
discharging a secondary medium into and out of the casing
spaces. On both axial ends of the tubular casing portion 1
are flanges 13 and two head pieces 2, 3, which are disposed
-4-
CA 02342425 2004-08-16
30177-1
adjacent to the opposite axial ends of the tubular casing
portion 1. The head pieces 2, 3 respectively have an inlet
and an outlet connection piece 21, 31 for a primary medium
to be conducted through the tube bundles. The head
pieces 2, 3 each have an associated cover plate 22, 32 that
can be clamped together with the flanges 13 of the casing 1
by screws or threaded rods 23, 33.
A plurality of tube bundles 5, specifically, in
the exemplary embodiment illustrated, three tube bundles,
which are designated 5A, 5B, and 5C, are installed in the
casing. Each tube bundle includes a number of parallel heat
exchanger tubes 51 disposed at distances from one another
and two tube sheets 52 are respectively connected to these
and located at the two opposite axial ends of the tube
bundle.
Each tube bundle comprising a number of heat
exchanger tubes 51 and the associated tube sheets 52 forms a
separate module in the form of an integral unit and is
installed as such in the casing. The seals 53 used for
sealing off between the tubular casing portion 1, head
pieces 2, 3, and the tube sheets 52 are illustrated only
schematically in the drawings and can be implemented as
0-ring seals or any other desired way, as required.
The interior of the tubular casing portion 1 is
subdivided by partitions 14 into a number of chambers 10A,
lOB, lOC corresponding to the number of tube bundles 5. The
partitions 14 are provided at the top and bottom with
passage orifices 15 through which the individual chambers
10A, 10B, lOC are connected to one another. The passage
orifices can be selectively closed.
-5-
CA 02342425 2004-08-16
30177-1
As can be seen, the plenum chambers, which are
formed in the head pieces 2, 3, are not subdivided, but
extend over all three tube bundles, so that a parallel flow
through the three tube bundles 5A, 5B, 5C takes place. The
three tube bundles 5A, 5B, 5C are, therefore, flow-connected
in parallel.
Fig. 2 shows a configuration that, again, includes
a tubular casing portion 1 with three tube bundles 5A, 5B,
5C installed therein. The construction of the casing with a
tubular casing portion 1, head pieces 2, 3, and connection
pieces 11, 12, 21, 31 for the media involved in the heat
exchange and the subdivision of the casing interior by
partitions 14 into three chambers 10A, lOB, lOC correspond
to the configuration according to Fig. 1.
The three tube bundles 5A, 5B, 5C in Fig. 2 are
constructed in the same way as those in Fig. 1 and, again,
respectively include heat exchanger tubes 51 and two tube
sheets 52 at the two opposite axial ends of each tube bundle
5A, 5B, 5C, again, constituting an integral unit or separate
module made up of these parts.
However, as compared with the configuration
according to Fig. l, in the configuration according to
Fig. 2, the head pieces 2, 3 and the partitions 14 in the
casing 1 are modified such that, in the configuration in
Fig. 2, the three tube bundles are flow-connected in series.
Also, the secondary medium flowing in through the connection
piece 11 and flowing out through the connection piece 12 is
routed, in all three tube bundles, in counter-current to the
primary medium that flows in through the connection piece 21
and flows out through the connection piece 31 and that flows
-6-
CA 02342425 2004-08-16
30177-1
in succession through the heat exchanger tubes 51 of the
three tube bundles. For that purpose, the head pieces
2 and 3 are modified such that an inlet plenum chamber 24 is
formed above the inlet end of the first tube bundle 5C, as
seen in the direction of flow of the primary medium. Also,
a transfer chamber 35, 25 is formed respectively in the head
pieces 3, 2 for transferring the primary medium between the
adjacent ends of two fluidically successive tube bundles
(from 5C to 5B through the transfer chamber 35 or from
5B to 5A through the transfer chamber 25), and an outflow
plenum chamber 36 is formed above the outflow end of the
last tube bundle, as seen in the direction of flow of the
primary medium, that is to say 5A. Partitions 27, 37 for
appropriately subdividing the head piece interior spaces
into the corresponding chambers are, therefore, formed in
the head pieces 2, 3.
Only one transfer orifice 15 is provided in each
of the partitions 14 and is located near the respective tube
plates so that a secondary medium must in each case flow, in
counter-current to the medium flowing through the tube
bundles, through essentially the entire axial length of the
respective casing chamber until it can pass through the
respective transfer orifice 15 into the adjacent casing
chamber.
For constructing configurations according to
Figs. 1 and 2, standard partitions 14 may be used, which, as
illustrated in Fig. l, may have, at both axial ends,
transfer orifices, one of which is closed in each case to
produce a configuration according to Fig. 2.
Different head pieces with or without
partitions 27, 37 may also be kept ready, so that
_7_
CA 02342425 2004-08-16
30177-1
configurations according to Figs. 1 and 2 can be produced,
as required, from such elements in a modular manner.
Figs. 3 and 4 show configurations similar to those
according to Figs. 1 and 2, of a multiple tube bundle heat
exchanger with tube bundles flow-connected in parallel
(Fig. 3) or with tube bundles flow-connected in series
(Fig. 4). Identical or corresponding parts are, again,
given the same reference symbols as in Figs. 1 and 2.
The tube bundles 5A, 5B, 5C (of which there are,
again, for example, three in each case) correspond to those
according to Figs. 1 and 2. The head pieces 2, 3 also
correspond to those according to Figs. 1 and 2. The same
applies to the tubular casing portion 1 with the connection
pieces 11, 12.
The configurations according to Figs. 3 and 4,
however, differ from the configurations according to
Figs. 1 and 2 in a modification or development of the casing
structure. For, in the configurations according to
Figs. 3 and 4, the partitions 14 are configured without
transfer orifices, that is to say, are completely closed.
Instead, in the configurations according to Figs. 3 and 4,
the head pieces 2, 3 are each supplemented by an
intermediate piece 4 that is disposed between the respective
head piece and the flange 13 of the tubular casing portion 1
and that forms prolongations of the partitions 14, or, where
fluid shall pass between adjacent casing chambers, have a
transfer orifice 41.
As a result, the tubular casing portion 1 of the
casing, together with the partitions 14, can be configured
as a standard part, while different intermediate pieces 4
_g_
CA 02342425 2004-08-16
30177-1
can be kept ready, as required, as parts to be used in a
modular manner to produce transfer orifices between the
casing chambers.
In configurations according to Figs. 3 and 4, if
the intermediate pieces 4 have sufficient axial length, the
connection pieces for the tubular casing portion (in the
embodiments illustrated, designated by 11 and 12 and
disposed on the tubular casing portion 1) may also be
disposed on the intermediate pieces 4. In such a case, it
is possible not only to mount one or both connection pieces
laterally on the respective intermediate piece 4, but also
to configure it axially and lead it through the respective
head piece 2, 3.
The above embodiments were described as counter-
current heat exchangers by virtue of the arrows indicated in
the drawings. It goes without saying that they may also be
operated in the same way as co-current heat exchangers, for
which purpose only the direction of flow of one of the two
media needs to be reversed.
The concept according to the invention makes it
possible to construct any desired heat exchangers using
standard components. In particular, the tube bundles may be
configured as standard components, from which any desired
multiple tube bundle heat exchanger configurations of
different size can be constructed, regardless of the
intended operation as co-current or counter-current heat
exchangers. For heat exchangers of different sizes,
different housing structural parts, to be precise casings
and head pieces, may be kept ready, these respectively being
configured to receive a specific number of tube bundles, or
-9-
CA 02342425 2004-08-16
30177-1
variable block configurations of such casing structural
parts may be provided. By using appropriate head pieces, to
be precise, one for the tube bundles operating in parallel
and one for the tube bundles connected in series, heat
exchanger configurations can be constructed as required from
relatively few basic components in a modular manner and,
therefore, highly economically.
-10-
