Note: Descriptions are shown in the official language in which they were submitted.
CA 03014091 2018-08-09
WO 2017/137054 Al
CROSS-FLOW PLATE HEAT AND/OR MOISTURE EXCHANGER
The invention relates to a cross-flow plate heat and/or
moisture exchanger having plates which are arranged above,
below or next to one another and form alternating flow
passages for a first and a second fluid.
Based on the above-mentioned state of the art the invention
is based on the requirement to provide an improved cross-flow
plate heat and/or moisture exchanger, which on the one hand
exhibits better transfer performance during the transfer of
heat and/or moisture between the two fluids and which
moreover has increased pressure stability in relation to
differential pressures between the two fluid flows.
According to the invention this requirement is met in that
each plate of the cross-flow plate heat and/or moisture
exchanger has a first cross-flow region, a counter-flow
region following the first cross-flow region in flow
direction and a second cross-flow region following the
counter-flow region in flow direction, in that the cross-flow
regions of neighbouring plates form flow channels running
approximately perpendicular to each other, in that the
counter-flow regions of neighbouring plates form flow
channels running approximately parallel to one another, in
that the first or the second cross-flow region of each plate
in terms of its dimensions corresponds to the second or first
cross-flow region of each neighbouring plate and is arranged
above, below or next to the same, and in that the counter-
flow region of each plate in terms of its dimensions
corresponds to the counter-flow region of each neighbouring
plate and is arranged above, below or next to the same.
CA 03014091 2018-08-09
- 2 -
Due to this design of the two differently constructed plates,
which are combined to form the cross-flow plate heat and/or
moisture exchanger, it is achieved that the two fluids
flowing through the cross-flow plate heat and/or moisture
exchanger flow essentially anti-parallel to one another, as a
result of which the efficiency of the cross-flow plate heat
and/or moisture exchanger is considerably improved in
comparison to corresponding aggregates known from the state
of the art. Due to the flow channels running perpendicular to
one another a mechanically stable design of the cross-flow
plate heat and/or moisture exchanger is obtained. Since a
counter-flow region is provided in each flow passage of the
cross-flow plate heat and/or moisture exchanger according to
the invention, it is ensured that the two fluids in this
counter-flow region are guided past each other in an
approximately anti-parallel manner. According to the
invention it has become possible to steer the flow direction
of the first fluid in direction of the entry of the second
fluid so that the temperature or the moisture of the first
fluid can move closer to the entry temperature or moisture of
the second fluid. Similarly the temperature and/or the
moisture of the second fluid can move closer to the entry
temperature or moisture of the first fluid. By proceeding in
this way high degrees of transfer are achievable which lie in
the range of up to 90%.
The first cross-flow region of each plate causes the
respective fluid flow to be evenly distributed across the
counter-flow region of each plate. Due to the difference in
design of the neighbouring plates, these can mutually support
each other very well, wherein nevertheless, in the area of
the respective counter-flow regions, an approximately
parallel progression of the respective flow channels is made
possible.
CA 03014091 2018-08-09
- 3 -
In order to ensure that the stability of the plate packet of
the cross-flow plate heat and/or moisture exchanger according
to the invention also in the area of the counter-flow regions
of the plates is of high quality even for the most varied
pressures in the different fluids, it is advantageous if the
counter-flow channels of the cross-flow region of each
neighbouring plate extend at a slight incline of preferably 5
to 25 degrees. This ensures an approximately parallel
progression of the counter-flow channels formed by the
neighbouring plates in the neighbouring flow passages,
wherein moreover it is ensured that the neighbouring plates
are mechanically firmly supported against each other.
When the direction of counter-flow channels of the counter-
flow regions of the plates changes, turbulences can be
initiated in the flows of the two fluids, which can
contribute to an improvement of the transfer conditions of
heat and/or moisture right through the plates between the two
fluids.
In order to keep the installation cost for the cross-flow
plate heat and/or moisture exchanger according to the
invention to a minimum and in order to be able to ensure
reliable sealing on the plate edges at a minimum of
engineering effort, it is advantageous if the plates are
shaped in the form of a rectangle or a square.
According to an advantageous embodiment of the cross-flow
plate heat and/or moisture exchanger according to the
invention the counter-flow regions of each plate are shaped
as an approximate oval or ellipse extending between two
opposing corners of the plate.
CA 03014091 20113--09
,
- 4 -
According to a further advantageous embodiment of the cross-
flow plate heat and/or moisture exchanger according to the
invention the general flow direction A, B through the cross-
flow plate heat and/or moisture exchanger, of the two fluids
separated from each other by the plates, is chosen such that
the two fluids flow through the counter-flow regions of the
cross-flow plate heat and/or moisture exchanger in counter
direction, i.e. approximately anti-parallel.
If walls of the flow channels of the cross-flow regions,
which are arranged between the plates, are formed in a steady
or uninterrupted manner, the flow conditions in the cross-
flow regions of the cross-flow plate heat and/or moisture
exchanger according to the invention are comparatively regular
and orderly, which for certain requirement profiles on the
cross-flow plate heat and/or moisture exchanger is convenient
and advantageous.
If the requirement profiles for the cross-flow plate heat
and/or moisture exchanger according to the invention are of a
different kind, i.e. if more turbulent flow conditions are
desired in the cross-flow regions thereof, it is convenient
if walls of the flow channels of the cross-flow regions
arranged between the plates comprise interruptions.
Particularly advantageous materials for the plates of the
cross-flow plate heat and/or moisture exchanger according to
the invention have proved to be aluminium and plastic,
preferably PET plastic, in particular then, when the cross-
flow plate heat and/or moisture exchanger according to the
invention is to be used merely for temperature transfer
between the two fluids.
CA 03014091 2018-08-09
,
- 5 -
If the cross-flow plate heat and/or moisture exchanger
according to the invention is to be used also or
predominantly for moisture or enthalpy exchange between the
two fluids, it is advantageous if the plates are configured
as membrane plates. In this case each membrane plate
comprises a membrane layer and a carrier layer. By means of
the membrane layer enthalpy can be transferred between the
two fluids. The at least one carrier layer is configured
perforated. By means of the perforated carrier layer the
membrane plate can be given a specifiable mechanical strength
and a spatial structure, wherein both the mechanical strength
and the spatial structure can be permanently maintained.
The membrane layer of the plates is conveniently formed of a
suitable plastic material, preferably a polyurethane or a
polymer material.
The carrier layer of the plates is conveniently formed of a
suitable fleece material, preferably a polyester material.
The invention will now be described in detail by way of an
embodiment with reference to the drawing, in which
figure 1 shows an embodiment of a plate of the first design
for a cross-flow plate heat and/or moisture exchanger
according to the invention comprising two differently
constructed plates;
figure 2 shows an embodiment of a plate of the second design
for a cross-flow plate heat and/or moisture exchanger
according to the invention comprising two differently
constructed plates; and
figure 3 shows a schematic diagram of a cross-flow plate heat
and/or moisture exchanger according to the invention
comprising embodiments of plates depicted in figures 1 and 2.
CA 03014091 2018-08-09
- 6 -
A cross-flow plate heat and/or moisture exchanger 1 according
to the invention shown in a schematic diagram in figure 3
consists of a plate packet composed of plates 2, 3 of
different design or construction. Within the plate packet the
plates 2 and the plates 3 are arranged in an alternating
manner, i.e. a plate 2 of the first construction type is
followed respectively by a plate 3 of the second construction
type. Accordingly each plate 2 of the first construction type
has two neighbouring plates 3 of the second construction type
and vice-versa. In the case of the embodiment shown in figure
3, the plates 2, 3 are arranged on top of each other. It is,
of course, possible to arrange the plates 2, 3 adjacently to
each other.
The two sides of the plates 2, 3 facing each other limit flow
passages for a first fluid which flows through the cross-flow
plate heat and/or moisture exchanger 1 of figure 1 in a
general direction indicated by arrows A, and for a second
fluid, which flows through the cross-flow plate heat and/or
moisture exchanger 1 of figure 2 in a general direction
indicated by arrows B. The general direction A of the first
fluid is approximately perpendicular to the general direction
B of the second fluid.
The flow passages for the first fluid and for the second
fluid are arranged in an alternating manner in the plate
packet shown in figure 3 made up of plates 2, 3.
The flow passages for the first fluid are determined by the
design shown in figure 1 of the plate 2 of the first
construction type. The flow passages for the second fluid are
determined by the design shown in figure 2 for the plate 3 of
the second construction type.
CA 03014091 2018-08-09
- 7
The plates 2, 3 of the cross-flow plate heat and/or moisture
exchanger I may be made of any suitable material, e.g.
aluminium or a PET material.
If the cross-flow plate heat and/or moisture exchanger 1 is
also to be used essentially for moisture or enthalpy exchange
between the two fluids which flow through the same, the
plates 2, 3 of the cross-flow plate heat and/or moisture
exchanger I are configured as membrane plates. The respective
membrane plates consist of a membrane layer by means of which
enthalpy can be transferred between the two fluids, and at
least one perforated carrier layer by means of which a
specifiable mechanical strength and a spatial structure can
be imparted to the membrane plate and be maintained therein.
The membrane layer of plates 2, 3 is then formed from a
suitable plastic material, in particular a polyurethane or a
polymer material.
The carrier layer of the plates 2, 3 is then formed from a
suitable fleece material, preferably from a polyester fleece
or similar.
The flow passages, which are provided in the cross-flow plate
heat and/or moisture exchanger 1 for the first fluid, are
designed according to the structure of plate 2 of the first
construction type as depicted in the following in figure 1.
In case of the embodiment shown in figure 1 the plate 2 has a
first cross-flow region 4, into which the first fluid enters.
The first cross-flow region 4 comprises flow channels 5
extending in parallel, through which the first fluid is
guided to a counter-flow region 6 following the first cross-
flow region 4. In the embodiment shown the counter-flow
CA 03014091 2018-08-09
- 8 -
region 6 comprises a larger number of counter flow channels 7
in comparison to the number of flow channels 5 of the first
cross-flow region 4. The counter-flow channels 7 are arranged
at an incline to the flow channels 5. Moreover the counter-
flow channels 7, as from a certain length, comprise length
portions of varying direction. The varying length of the
counter-flow channels 7 stems from the fact that the counter-
flow region 6 of the first plate 2 extends from the right
upper corner 8 thereof in figure 1 to the left lower corner 9
thereof in figure 1 and comprises an elliptical or oval shape
tapering in direction of the corners 8, 9.
The first fluid is guided through the multiplicity of
counter-flow channels 7 to a second cross-flow region 10 of
the plate 2. The second cross-flow region 10 comprises flow
channels 11, which extend in parallel to the flow channels 5
of the first cross-flow region 4 and which respectively
extend in the general direction A, in which the first fluid
flows through the cross-flow plate heat and/or moisture
exchanger 1.
The flow passages, which are provided in the cross-flow plate
heat and/or moisture exchanger 1 for the second fluid, are
designed according to the structure of plate 3 of the second
construction type as depicted in the following in figure 2.
In case of the embodiment shown in figure 2 the plate 3 has a
first cross-flow region 12, into which the second fluid
enters. The first cross-flow region 12 comprises flow
channels 13 extending in parallel, through which the second
fluid is guided to a counter-flow region 14 following the
first cross-flow region 12. In the embodiment shown the
counter-flow region 14 comprises a larger number of counter
flow channels 15 in comparison to the number of flow channels
13 of the first cross-flow region 12. The counter-flow
CA 03014091 2018-08-09
k
- 9 -
channels 15 are arranged at an incline to the flow channels
13. Moreover the counter-flow channels 15, as from a certain
length, comprise length portions of varying direction. The
varying length of the counter-flow channels 15 stems from the
fact that the counter-flow region 14 of the second plate 3
extends from the right upper corner 16 thereof in figure 2 to
the left lower corner 17 thereof in figure 2 and comprises an
elliptical or oval shape tapering in direction of the corners
16, 17.
The second fluid is guided through the multiplicity of
counter-flow channels 15 to a second cross-flow region 18 of
the plate 3. The second cross-flow region 18 comprises flow
channels 19, which extend in parallel to the flow channels 13
of the first cross-flow region 12 and which respectively
extend in the general direction B, in which the second fluid
flows through the cross-flow plate heat and/or moisture
exchanger 1.
As already explained, the plate packet of the cross-flow
plate heat and/or moisture exchanger 1 is constructed by
arranging the differently constructed plates 2, 3 depicted in
figure 1 and figure 2 in an alternating manner on top of each
other. As can be seen in figure 1 and figure 2, the first
cross-flow region 4 of plate 2, in terms of its layout and
its dimensions, corresponds to plate 3 depicted in figure 2.
Analogously the second cross-flow region 10 of plate 2
depicted in figure 1, in terms of its shape and its
dimensions, corresponds to the first cross-flow region 12 of
plate 3 depicted in figure 2. The first fluid and the second
fluid, in the cross-flow regions 4, 10, 12, 18 of the two
plates 2, 3, flow in their general directions A or B and thus
approximately perpendicular to each other.
CA 03014091 2018-08-09
- 10 -
The plates 2, 3 in the embodiments shown in figures 1 and 2
are shaped approximately as a square. Since the contours and
the layout of the cross-flow regions 4 and 18 / 10 and 12 of
plates 2, 3 correspond to each other, this also applies to
the contours and the layout of the counter-flow regions 6, 14
of the two plates 2,3.
In the counter-flow regions 6 and 14 the first fluid and the
second fluid flow in an opposite or anti-parallel flow
direction. The directional changes of the counter-flow
channels 7 and 15 provided in the counter-flow regions 6, 14
cause irregularities or turbulences of the flows of the first
fluid and of the second fluid, which contributes to an
improvement in the heat and/or moisture transfer between the
fluids 1, 2.
The general flow direction of fluid 1 in the counter-flow
region 6 as well as of fluid 2 in the counter-flow region 14,
with the plates 2, 3 shown in figures 1 and 2, occurs at an
angle of approximately 45 degrees to the general directions A
and B of fluid 1 and fluid 2, respectively. The counter-flow
channels 7 of the counter-flow region 6 of plate 2 are, in
the case of plates 2, 3 depicted in figures 1 and 2, inclined
by a comparatively small angle, which may be between 5
degrees and 25 degrees, in relation to the counter-flow
channels 15 of the counter-flow region 14 of plate 2. This
ensures that the mechanical structure of the plate packet
forming the cross-flow plate heat and/or moisture exchanger 1
is stable with the distances between plates 2, 3 remaining
unchanged even in the area of their counter-flow regions 6,
14. When assembling the plate packet of the above-described
cross-flow plate heat and/or moisture exchanger 1 it must be
ensured that the entry section associated with the first
fluid and the entry section associated with the second fluid
CA 03014091 2018-08-09
- 11 -
are arranged in relation to one another in such a way that
the first and the second fluid flow in opposite directions in
the counter-flow regions 6, 14.
In the exemplary embodiment shown walls 20 of the flow
channels 5 of the first cross-flow region 4 of plate 2, walls
21 of the flow channels 11 of the second cross-flow region 10
of plate 2, walls 21 of the flow channels 13 of the first
cross-flow region 12 of plate 3 and walls 23 of flow channels
19 of the second cross-flow region 18 of plate 3 are
constructed without interruptions, i.e. in a steady and
continuous manner. Interruptions between the said walls, in
the case of plates 2, 3 depicted in figures 1 and 2, exist in
particular at the transitions between the cross-flow regions
4, 10, 12, 18 and the counter-flow regions 6, 14.
Where more turbulent flow conditions are desired or necessary
in the cross-flow regions 4, 10, 12, 18, the walls of flow
channels 5, 11, 13, 19 may, of course, also have
interruptions.
