U.S. patent application number 13/581912 was filed with the patent office on 2012-12-27 for plate heat exchanger plate and plate heat exchanger.
This patent application is currently assigned to ALFA LAVAL CORPORATE AB. Invention is credited to Fredrik Blomgren, Ralf Blomgren.
Application Number | 20120325434 13/581912 |
Document ID | / |
Family ID | 44626513 |
Filed Date | 2012-12-27 |
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United States Patent
Application |
20120325434 |
Kind Code |
A1 |
Blomgren; Ralf ; et
al. |
December 27, 2012 |
PLATE HEAT EXCHANGER PLATE AND PLATE HEAT EXCHANGER
Abstract
A plate heat exchanger plate with a main heat transfer portion
comprising a first area comprising a first field with first
corrugations arranged substantially on one side of a straight first
line intersecting with second side edges and a second field with
second corrugations arranged substantially on an opposite side of
the first line is provided. The main heat transfer portion
comprises a first outer area arranged between a first area and a
first of the second side edges and extends along the first second
side edge between two distribution portions. In the first outer
area there are arranged first protrusions and recesses directed in
a first general direction in relation to a straight second line
parallel to one of first side edges. A plate with a straight first
second edge may thus be provided when corrugations in the first
area are directed in different directions.
Inventors: |
Blomgren; Ralf; (Skanor,
SE) ; Blomgren; Fredrik; (Malmo, SE) |
Assignee: |
ALFA LAVAL CORPORATE AB
Lund
SE
|
Family ID: |
44626513 |
Appl. No.: |
13/581912 |
Filed: |
April 11, 2011 |
PCT Filed: |
April 11, 2011 |
PCT NO: |
PCT/SE11/50434 |
371 Date: |
August 30, 2012 |
Current U.S.
Class: |
165/104.19 |
Current CPC
Class: |
F28F 2215/04 20130101;
F28F 3/046 20130101; F28F 3/083 20130101; F28F 9/026 20130101 |
Class at
Publication: |
165/104.19 |
International
Class: |
F28D 15/00 20060101
F28D015/00 |
Claims
1. A plate heat exchanger plate delimited by two substantially
parallel first side edges and two substantially parallel second
side edges and provided with port holes adjacent a first
distribution portion at a first end of said plate, port holes
adjacent a second distribution portion at a second end of said
plate, and between said first and second distribution portions a
main heat transfer portion comprising a corrugation pattern,
wherein said main heat transfer portion comprises a first area
comprising a first field with first corrugations arranged
substantially on one side of a straight first line intersecting
with said second side edges and a second field with second
corrugations arranged substantially on an opposite side of said
first line, and wherein said first corrugations comprise ridges and
grooves directed at an angle of between 0-<90 degrees with said
first line measured in a clockwise or counter clockwise angular
direction and said second corrugations comprise ridges and grooves
directed at an angle of between >270-<360 degrees with said
first line measured in said angular direction, wherein said main
heat transfer portion comprises a first outer area arranged between
said first area and a first of said second side edges and extends
along said first second side edge between said first and second
distribution portions, wherein in said first outer area there are
arranged first protrusions and recesses directed in a first general
direction in relation to a straight second line parallel to one of
said first side edges.
2. The plate according to claim 1, wherein said main heat transfer
portion comprises a second outer area arranged between said first
area and a second of said second side edges opposite to said first
outer area and extends along said second of said second side edges
between said first and second distribution portions, wherein in
said second outer area there are arranged second protrusions and
recesses directed in a second general direction in relation to said
second line.
3. The plate according to claim 1, wherein said first area
comprises a third field with third corrugations comprising ridges
and grooves arranged substantially on said one side of said first
line and directed at an angle of between >90-<180 degrees
from said first line in said angular direction and a fourth field
with fourth corrugations comprising ridges and grooves arranged
substantially on said opposite side of said first line and directed
at an angle of between >180-<270 degrees from said first line
in said angular direction.
4. The plate according to claim 1, wherein said ridges and grooves
of said first corrugations are directed at an angle of between
>45-<90 degrees with said first line measured in said angular
direction and said ridges and grooves of said second corrugations
are directed at an angle of between >270-<315 degrees with
said first line measured in said angular direction.
5. The plate according to claim 3, wherein said ridges and grooves
of said third corrugations are directed at an angle of between
>90-<135 degrees with said first line measured in said
angular direction and said ridges and grooves of said fourth
corrugations are directed at an angle of between >225-<270
degrees with said first line measured in said angular
direction.
6. The plate according to claim 2, wherein said first general
direction and/or said second general direction comprise/s one or
more angles between 0-<90 degrees in relation to said second
line.
7. The plate according to claim 2, wherein said first outer area
and/or said second outer area have/has a width measured in parallel
with said second line, which is narrower than said first field
measured in parallel with said second line.
8. The plate according to claim 2, wherein said first and/or second
protrusions and recesses in said first outer area and/or said
second outer area comprise corrugations in the form of ridges and
grooves.
9. The plate according to claim 8, wherein in said first and second
outer areas said ridges have a different width than said grooves
measured across said ridges and grooves.
10. The plate according to claim 2, wherein said first protrusions
and recesses are directed in a first direction in relation to said
second line and/or said second protrusions and recesses are
directed in a second direction in relation to said second line.
11. The plate according to claim 1, wherein said first side edges
are short sides and said second side edges are long sides of said
plate.
12. The plate according to claim 2, wherein said first outer area
and/or said second outer area are/is divided into two or more
fields.
13. A plate heat exchanger comprising a plate package of plate heat
exchanger plates according to claim 1.
14. The plate heat exchanger according to claim 13, wherein said
plate heat exchanger plates are arranged alternately in said plate
package such that a first outer area of one plate abuts a second
outer area of an abutting plate.
15. The plate heat exchanger according to claim 13, which is
adapted for substantially parallel flow of at least two heat
exchange fluid over said main heat transfer portion of plates in
said plate package.
Description
AREA OF INVENTION
[0001] The present invention relates to a plate heat exchanger
plate according to the precharacterizing portion of claim 1 and a
plate heat exchanger comprising such a plate.
BACKGROUND OF INVENTION
[0002] Plate heat exchangers provided with a plate package of plate
heat exchanger plates are utilized for exchange of heat between two
or more heat exchange fluids. The plates form plate interspaces
adapted to be flowed through by the heat exchange fluids. The
plates are provided with port holes which form channels extending
through the plate package. In case of heat exchange between the two
heat exchange fluids each channel communicates with every second
plate interspace. A first heat exchange fluid flows from a first
channel through each alternate plate interspace over heat exchange
surfaces of the plates to a second channel at an opposite end of
the plate package. A second heat exchange fluid flows from a third
channel through every other alternate plate interspace over heat
exchange surfaces on opposite sides of the plates to a fourth
channel at an opposite end of the plate package. The heat exchange
fluids may be e.g. gases, liquids, liquids containing solid matter,
etc.
[0003] The heat exchange surfaces of the heat exchange plates are
provided with corrugations. These corrugations may have many
different forms but generally comprises elevated and depressed
portions. The corrugations may define the width of the plate
interspaces, create a turbulent flow in the plate interspaces and
serve as a support for adjacent plates in the plate package. The
plates are commonly manufactured from sheet metal, which is
provided with the corrugations in one or more pressing
operations.
[0004] There are many different corrugation patterns used for heat
exchange plates. One type of corrugation pattern comprises first
ridges and grooves arranged in a first direction and second ridges
and groove arranged in a second direction such that a V-shaped
pattern resembling a herringbone pattern is formed at least in some
portions of the plate.
[0005] When the V-shaped pattern of corrugations comprising ridges
and grooves points in a direction from an edge of a plate towards
the centre of the plate, edge portions of the plate may be deformed
due to the sheet metal material being displaced in the pressing
operation. Also when the V-shaped pattern is arranged in proximity
of a plate edge and points in a different direction, the relevant
edge portion may be affected. Besides not looking good, deformed
edge portions may cause weak edges of the plate. In particular
plate heat exchangers with gaskets arranged between the plates must
have strong stable edge portions to prevent leakage of the plate
heat exchanger. In order to prevent weak edges, the sheet metal
blanks from which the heat exchanger plates are manufactured, must
be cut larger than for heat exchanger plates with other corrugation
patterns. Accordingly, the utilization of sheet metal material is
not optimal.
[0006] WO94/19657 discloses such a heat exchanger plate, where
several such above mentioned V-shaped patterns point towards the
centre of the plate and towards the edges of the plate.
DISCLOSURE OF INVENTION
[0007] An object of the present invention is to provide plate heat
exchanger plates with uniformly displaced edges, thus allowing a
design with efficient use of sheet material for heat transfer
purposes.
[0008] According to an aspect of the invention, the object is
achieved by a plate heat exchanger plate delimited by two
substantially parallel first side edges and two substantially
parallel second side edges and provided with port holes adjacent a
first distribution portion at a first end of the plate, port holes
adjacent a second distribution portion at a second end of the
plate, and between the first and second distribution portions a
main heat transfer portion comprising a corrugation pattern. The
main heat transfer portion comprises a first area comprising a
first field with first corrugations arranged substantially on one
side of a straight first line intersecting with the second side
edges and a second field with second corrugations arranged
substantially on an opposite side of the first line. The first
corrugations comprise ridges and grooves directed at an angle of
between 0-<90 degrees with the first line measured in a
clockwise or counter clockwise angular direction. The second
corrugations comprise ridges and grooves directed at an angle of
between >270-<360 degrees with the first line measured in the
angular direction. The main heat transfer portion comprises a first
outer area arranged between the first area and a first of the
second side edges and extends along the first second side edge
between the first and second distribution portions. In the first
outer area there are arranged first protrusions and recesses
directed in a first general direction in relation to a straight
second line parallel to one of the first side edges.
[0009] Since the first outer area comprises first protrusions and
recesses directed only in a first general direction, the first
second side edge is uniformly affected during a pressing operation,
despite the first area of the main heat transfer portion comprising
corrugations which may displace portions of the sheet material
forming the plate in a pressing operation. As a result, the above
mentioned object is achieved. A straight edge comparatively close
to the main heat transfer portion is achieved. Thus, a larger part
of the plate may be utilized for heat transfer than if the plate
would not be provided with the first outer area of the above
mentioned kind.
[0010] The protrusions and recesses form corrugations of the heat
exchange plate and may have different forms such as singular tips
and dimples or ridges and grooves. In any case, the protrusions and
recesses form a pattern which may be seen to have a direction. The
protrusions and recesses in the first outer area are directed only
in the first general direction in relation to the second line. By
general direction in relation to the second line is meant that the
direction of the protrusions and recesses may vary in different
portions of the outer area but that the general direction in the
different portions is the same, for instance within 90 degrees of
the second line.
[0011] According to example embodiments the main heat transfer
portion may comprise a second outer area arranged between the first
area and a second of the second side edges opposite to the first
outer area and extend along the second of the second side edges
between the first and second distribution portions, wherein in said
second outer area there are arranged second protrusions and
recesses directed in a second general direction in relation to said
second line. In this manner also the second of the second side
edges may be maintained straight during manufacturing of the heat
exchanger plate.
[0012] According to example embodiments the first area may comprise
a third field with third corrugations comprising ridges and grooves
arranged substantially on the said one side of the first line and
directed at an angle of between >90-<180 degrees from the
first line in the angular direction and a fourth field with fourth
corrugations comprising ridges and grooves arranged substantially
on the opposite side of the first line and directed at an angle of
between >180-<270 degrees from the first line in the angular
direction. A plate comprising such third and fourth fields may have
V-shaped corrugation formations pointing towards the centre of the
plate from both sides and thus may benefit from the outer areas
arranged along both second sides.
[0013] According to example embodiments the ridges and grooves of
the first corrugations may be directed at an angle of between
>45-<90 degrees with the first line measured in the angular
direction and the ridges and grooves of the second corrugations may
be directed at an angle of between >270-<315 degrees with the
first line measured in the angular direction. Ridges and grooves of
the first and second corrugations with these specified angles form
a corrugation pattern which subjects a heat exchange fluid to a
relatively low flow resistance. In a pressing operation the ridges
and grooves of the first and second corrugations with these
specified angles are particularly prone to displace the sheet
material from which the plate is formed and may benefit from at
least one outer area on the main heat transfer portion.
[0014] According to example embodiments the ridges and grooves of
the third corrugations may be directed at an angle of between
>90-<135 degrees with the first line measured in the angular
direction and the ridges and grooves of the fourth corrugations may
be directed at an angle of between >225-<270 degrees with the
first line measured in the angular direction. In a pressing
operation the ridges and grooves of the third and fourth
corrugations with these specified angles are again, particularly
prone to displace the sheet material from which the plate is formed
and may benefit from a second outer area on the main heat transfer
portion.
[0015] According to example embodiments the first general direction
and/or the second general direction may comprise one or more angles
between 0-<90 degrees in relation to the second line. The first
and second general direction may be the same direction or they may
be directed differently from each other.
[0016] According to example embodiments the first outer area and/or
the second outer area may have a width measured in parallel with
the second line, which is narrower than the first field measured in
parallel with the second line. The first and second outer areas may
thus form peripheral areas of the main heat transfer portion.
[0017] According to example embodiments the first and/or second
protrusions and recesses in the first outer area and/or the second
outer area may comprise corrugations in the form of ridges and
grooves.
[0018] According to example embodiments, in the first and second
outer areas the ridges may have a different width than the grooves
measured across the ridges and grooves. For instance may all of the
ridges be wider than all of the grooves, or all of the ridges may
be narrower than all of the grooves. In this manner different flow
resistances for a heat exchange fluid flowing in a plate interspace
between two plate heat exchanger plates may be created. Thus, an
even distribution of heat exchange fluid over the entire main heat
transfer portion may be promoted.
[0019] According to example embodiments the first protrusions and
recesses may be directed in a first direction in relation to the
second line and/or the second protrusions and recesses may be
directed in a second direction in relation to the second line. The
protrusions and recesses in the first outer area may thus be
directed in one direction only in relation to the second line.
Similarly, the protrusions and recesses in the second outer area
may thus be directed in one direction only in relation to the
second line. In this manner the plate will be uniformly affected
near the second side edges during forming of the plate in one or
more pressing operation.
[0020] According to example embodiments the first side edges may be
short sides and the second side edges may be long sides of the
plate.
[0021] According to example embodiments the first outer area and/or
the second outer area may be divided into two or more fields. This
may stabilize a large plate heat exchanger plate.
[0022] According to an aspect of the invention there is provided a
plate heat exchanger comprising a plate package of plate heat
exchanger plates according to any aspect or example embodiment
mentioned above.
[0023] According to example embodiments the plate heat exchanger
plates may be arranged alternately in the plate package such that a
first outer area of one plate abuts a second outer area of an
abutting plate. In this manner the plate interspaces between the
plates in the areas of the outer areas may be defined by different
outer areas of the two abutting plates. In example embodiments only
one type of plate heat exchanger plate may be required to form the
plate package.
[0024] According to example embodiments the plate heat exchanger
may be adapted for substantially parallel flow of at least two heat
exchange fluid over the main heat transfer portion of plates in the
plate package.
[0025] Further features of, and advantages with, the present
invention will become apparent when studying the appended claims
and the following description. Those skilled in the art will
realize that different features of the present invention may be
combined to create embodiments other than those described in the
following, without departing from the scope of the present
invention, as defined by the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The various aspects of the invention, including its
particular features and advantages, will be readily understood from
the following detailed description and the accompanying drawings,
in which:
[0027] FIGS. 1 and 2 schematically illustrate plate heat exchanger
plates according to example embodiments,
[0028] FIG. 3 illustrates schematically a cross section through
parts of a plate package of a plate heat exchanger, and
[0029] FIG. 4 illustrates a plate heat exchanger according to
example embodiments.
DETAILED DESCRIPTION OF EMBODIMENTS
[0030] The present invention will now be described more fully with
reference to the accompanying drawings, in which example
embodiments are shown. However, this invention should not be
construed as limited to the embodiments set forth herein. Disclosed
features of example embodiments may be combined as readily
understood by one of ordinary skill in the art to which this
invention belongs. Like numbers refer to like elements
throughout.
[0031] Well-known functions or constructions may not be described
in detail for brevity and/or clarity.
[0032] FIG. 1 schematically illustrates a plate heat exchanger
plate 2 according to example embodiments. Several of such plates 2
are arranged in a plate package of a plate heat exchanger. The
plate heat exchanger is arranged for heat exchange between two heat
exchange fluids when the two fluids flow through alternate plate
interspaces formed between the plates 2. The plate 2 is
substantially rectangular and has two first side edges 4a, 4b,
which form short sides of the plate 2 and two second side edges 6a,
6b, which form long sides of the plate 2. The plate 2 is provided
with four port holes 8a, 8b and 10a, 10b. The port holes 8a, 8b,
10a, 10b form four channels extending through the plate package.
Two of the channels communicate with every second plate interspace
and the other two channels communicate with the remaining plate
interspaces. In use, a first heat exchange fluid will flow through
a first port hole 8a over one side of the plate 2 to a second port
hole 8b and a second heat exchange fluid will flow over the other
side of the plate 2 between the third and fourth port holes 10a,
10b. Thus, heat from one of the heat exchange fluids is transferred
through the plate 2 to the other heat exchange fluid.
[0033] With reference to the visible side of the plate 2 in FIG. 1
there is provided in connection with the first port hole 8a a first
distribution portion 12a. In connection with the second port hole
8b there is provided a second distribution portion 12b. Between the
first and second distribution portions 12a, 12b there is arranged a
main heat transfer portion 14. The first distribution portion 12a
serves, in use, to distribute a relevant fluid over the width of
the main heat transfer portion 14. Consequently, the second
distribution portion 12b serves to funnel the fluid from the main
heat transfer portion 14 to the second port hole 8b. The
distribution portions 12a, 12b are provided with a corrugation
pattern, which may provide efficient distribution and funnelling of
the heat exchange fluid.
[0034] On the opposite side of the plate 2 there are provided
distribution portions in connection with the third and fourth port
holes 10a, 10b. These distribution portions, in use, have the same
function as the first and second distribution portions 12a, 12b,
although with respect to a different heat exchange fluid.
[0035] The plate 2 is provided with gasket grooves, which are
adapted to receive one or more gaskets. When one ore more gaskets
are arranged in the gasket grooves between two abutting plates 2,
the gasket/s delimit the port holes, distribution portions and main
heat transfer portion from the ambient environment, and in use seal
the plate interspace and channels formed by the port holes to
prevent leaking of heat exchange fluids. Accordingly, in the view
illustrated in FIG. 1 one gasket 15 is placed in the gasket groove
encircling an area comprising the first and second port holes 8a,
8b, the first and second distribution portions 12a, 12b and the
main heat transfer portion 14. Also, the gasket 15 is arranged
around each of the third and fourth port holes 10a, 10b.
Alternatively, separate gaskets may be used around each of the
third and fourth port holes 10a, 10b.
[0036] The main heat transfer portion 14 comprises three main areas
namely, a first area 16 arranged between a first outer area 18 and
a second outer area 20. The first area 16 comprises several fields
with corrugations comprising ridges and grooves directed in
different directions. In this example there are twelve such fields
in the first area 16, which are emphasized by continuous lines. The
first outer area 18 extends between the first and second
distribution portions 12a, 12b along a first of the second side
edges 6a and comprises three fields 22a, 22b, 22c. The second outer
area 20 extends between the first and second distribution portions
12a, 12b along a second of the second side edges 6b and comprises
three fields 24a, 24b, 24c.
[0037] A closer look will now be taken at the directions of the
ridges and grooves of the fields of the first area 16. For the
purpose of illustration a straight first line 26 intersects with
the two second side edges 6a, 6b. A first field 30 is arranged one
side of the first line 26. Measured in a clockwise direction the
ridges and grooves in the first field 30 are directed at an angle
of about 60 degrees with the first line 26. A second field 32 is
arranged on an opposite side of the line 26. Measured in the same
direction as the ridges and grooves in the first field 30, the
ridges and grooves in the second field 32 are directed at an angle
of about 300 degrees with the first line 26. On the same side of
the first line 26 as the first field 30 there is arranged a third
field 34 provided with ridges and grooves directed at an angle of
about 120 degrees with the first line 26, measured in the same
direction as before. On the same side of the first line 26 as the
second field 32 there is arranged a fourth field 36 provided with
ridges and grooves directed at an angle of about 240 degrees with
the first line 26, again measured in the same direction as
before.
[0038] The first and second outer areas 18, 20 are provided with
protrusions and recesses. In this embodiment the protrusions and
recesses are formed as ridges and grooves similar to the
corrugations in the first area 16. In the outer areas 18, 20 the
ridges and grooves have the same general direction in all three
fields 22a-c, 24a-c. In the first outer area 18 the ridges and
grooves in the middle field 22b have a slightly different angle
than in the two surrounding fields 22a, 22c. Similarly, in the
second outer area 20 the ridges and grooves do not have the same
direction in all three fields 24a, 24b, 24c. However, in all three
fields 22a-c, 24a-c of the first and second outer areas 18, 20 the
ridges and grooves all have the same general direction, i.e. the
angle of the ridges and grooves in the different fields is within
0-90 degrees of a straight second line 27 parallel to one of the
first side edges 4a.
[0039] In one or more pressing operations when the plate 2 is
manufactured from sheet metal, the corrugations may cause the plate
material to move, i.e. during pressing the plate material may be
displace at least to some extent. The corrugations in the first and
second fields 30, 32 form a V-shaped pattern pointing from the
first second side edge 6a towards the middle of the plate 2. In the
area of this V-shaped pattern the plate material may be moved
towards the middle of the plate 2. Thanks to the first outer field
18 arranged between the first area and the first second side edge
6a, the first second side edge 6a will be affected uniformly in the
pressing operation.
[0040] At other parts of the plate 2 the material may be displaced
in different directions during the pressing operation. However, the
first and second outer fields 18, 20 will ensure that the second
side edges 6a, 6b are displaced uniformly along the main heat
transfer portion 14 of the plate 2 during the pressing operation.
Accordingly, the second side edges 6a, 6b of the plate 2 will
remain substantially even also after the pressing operation.
[0041] FIG. 2 illustrates schematically a plate heat exchanger
plate 2 according to example embodiments. In general layout and
function the plate 2 corresponds to the plate 2 illustrated in FIG.
1. The main difference between the two plates is the first area 16
of the main heat transfer portion 14 of the plate 2. The
corrugation pattern of ridges and grooves in the first area 16 in
FIG. 2 is configured differently than in FIG. 1.
[0042] The first area 16 comprises several fields, in which the
ridges and groves of the corrugations are directed in different
directions. A straight first line 26 intersects with second side
edges 6a, 6b of the plate 2. A first field 30 is arranged on one
side of the first line 26. Measured in a clockwise direction the
ridges and grooves in the first field 30 are directed at an angle
of about 40 degrees with the first line 26. A second field 32 is
arranged on an opposite side of the line 26. Measured in the same
direction as the ridges and grooves in the first field 30, the
ridges and grooves in the second field 32 are directed at an angle
of about 320 degrees with the first line 26. The corrugations in
the first and second fields 30, 32 form a V-shaped pattern pointing
from a first of the second side edges 6a towards a second of the
second side edges 6b. Again, a first outer area 18 extends between
first and second distribution portions 12a, 12b along the first
second side edge 6a and a second outer area 20 extends between the
first and second distribution portions 12a, 12b along the second of
the second side edges 6b. In this embodiment the outer areas 18, 20
each comprise one field of protrusions and recesses in the form of
ridges and grooves. The ridges and grooves in the first outer area
18 are directed in one first direction only and the ridges and
grooves in the second outer area 20 are directed in one second
direction only.
[0043] Again, each of the first outer area 18 and the second outer
area 20 with their protrusions and recesses directed in one
direction in relation to a straight second line 27 parallel to a
first side edge 4a ensure that the second side edges 6a, 6b are
maintained essentially straight when the plate 2 is provided with a
corrugation pattern during manufacturing.
[0044] The first and second outer areas 18, 20, respectively, are
narrower that the first field 30 or the second field 32 in a
direction parallel to the second line 27. Thus, the first and
second outer areas 18, 20 form a smaller portion of the main heat
transfer portion 14 than the first area 16.
[0045] FIG. 3 illustrates schematically a cross section through
parts of a plate package 40 of a plate heat exchanger. The parts
illustrated correspond to portions of first and second outer areas
18, 20 of heat transfer plates 2. The plates 2 are provided with
ridges and grooves of different widths in the first and second
outer areas 18, 20. In an outer area 18, 20 e.g. all the ridges may
have the same width and all grooves may have the same widths, which
is narrower than the width of the ridges. Because of the ridges and
grooves having different widths, a plate interspace 42 between two
abutting plates 2 will be differently shaped at different sides of
the same plate interspace 42. A heat exchange fluid flowing through
the plate interspace 42 will thus be subject to different flow
resistances at the different sides of the same plate interspace
42.
[0046] In the following reference will be made to upper, left and
right sides of the plates 2 in the plate package 40. This is purely
for ease of explanation with reference to FIG. 3 and is in no way
limiting for aspects of the present invention. The ridges and
grooves of each plate 2 are differently formed on the left side and
the right side. That is, for instance the second plate 2 from the
top in the plate package 40, on its left side forms a first area
18, and on the right side forms a second outer area 20. In the view
illustrated in FIG. 3, the first area 18 is provided with wide
ridges and narrow grooves and the second area 20 is provided with
narrow ridges and wide grooves. The plate interspace 42 between two
abutting plates 2 is different on the left and right sides of the
plate package 40. As illustrated in FIG. 3, e.g. the two upper
plates 2 are arranged such that on the left side a second outer
area 20 of the top plate 2 abuts a first area 18 of the second
plate 2 from the top. Since wide ridges abut wide grooves, the flow
resistance will be high. Consequently, on the right hand side, the
flow resistance between the two uppermost plates 2 is low, because
here narrow ridges abut narrow grooves.
[0047] The plates 2 in the plate package 40 may be of the same
sort. The above mentioned arrangement of first and second outer
areas 18, 20 of different plates 2 may be achieved by rotating
every alternate plate 2 of the same sort 180 degrees about a
vertical axis 44. By arranging the gaskets in a suitable manner the
channels formed by the port holes through the plate package 40 and
the plate interspaces 42 are sealed.
[0048] As explained in connection with FIG. 1, the heat exchange
fluids are intended to flow in so called parallel flow over the
plates 2, i.e. one heat exchange fluid flows between the first and
second port holes 8a, 8b and the other heat exchanged fluid flows
between the third and fourth port holes 10a, 10b. In parallel flow
the distances a heat exchange fluid has to flow to pass a heat
exchange surface of the plate 2 varies over the width of the plate
2, the shortest distance will be along the second side edge 6a
closest to the first and second port holes 8a, 8b and the longest
distance will be from the first port hole 8a across the plate 2 to
the opposite second side edge 6b, along this second side edge 6b
and back across the to plate 2 to the second port hole 8b.
Similarly, on an opposite side of the plate a heat exchange fluid
will flow the shortest distance directly between the third an
fourth port holes 10a, 10b and for the longest distance the heat
exchange fluid has to cross the plate twice on its way between the
third and fourth port holes 10a, 10b. Thanks to the different flow
resistances in each one and the same plate interspaces 42, in use,
the distribution of the heat exchanged fluids in each plate
interspace 42 will be affected. If high flow resistance is provided
for the shortest path and low flow resistance for the longest path,
the heat exchange fluid will be distributed more evenly over the
entire relevant surface of the plate 2 than if the flow resistance
would equal in the shortest and longest paths.
[0049] FIG. 4 illustrates a plate heat exchanger 50 according to
example embodiments. The plate heat exchanger 50 comprises a plate
package 40 of plates 2 according to any of the above example
embodiments. Between the plates 2 there are arranged gaskets (not
visible). The plate package 40 is arranged in a frame 52 comprising
a frame plate 54, an upper bar 56 and a lower bar 58. The plate
package 40 is clamped between the frame plate 54 and a pressure
plate 60 by means of bolts 62 and nuts 64. The frame plate 54 is
provided with four openings 66, each one leading to a channel
formed by the four port holes 8a, 8b, 10a, 10b of the plates 2 in
the plate package 40.
[0050] Example embodiments may be combined as understood by a
person skilled in the art. For instance may an outer area
comprising several fields have one direction for the protrusions
and recesses in all fields. It is also understood by those skilled
in the art that the present invention may be utilized for plates of
other types of plate heat exchangers than plate heat exchanger
provided with gaskets, such as welded and brazed plate heat
exchangers.
[0051] Although the invention has been described with reference to
example embodiments, many different alterations, modifications and
the like will become apparent for those skilled in the art.
Different fields in the main heat transfer portion of a plate, i.e.
fields in the outer areas and/or the first area may be
distinguished from each other by different corrugation patters or
directions of corrugation patterns. Such fields may also be
separated by dedicated formations in the plate. Each field may be
separate or the fields may be separated two or more together. Also,
the plates may be adapted for diagonal flow of heat exchange fluids
instead of parallel flow. That is, the heat exchange fluids may be
intended to flow over the plate surface between port holes arranged
diagonally, at opposing ends of the plates. In this case the first
and second outer areas of the main heat transfer portions of the
plates may be formed such that the plate interspaces adjacent the
first and second outer areas are substantially similar along both
second side edges of the plate.
[0052] Therefore, it is to be understood that the foregoing is
illustrative of various example embodiments and the invention is
not to be limited to the specific embodiments disclosed and that
modifications to the disclosed embodiments, combinations of
features of disclosed embodiments as well as other embodiments are
intended to be included within the scope of the appended
claims.
[0053] As used herein, the term "comprising" or "comprises" is
open-ended, and includes one or more stated features, elements,
steps, components or functions but does not preclude the presence
or addition of one or more other features, elements, steps,
components, functions or groups thereof.
[0054] As used herein, the term "and/or" includes any and all
combinations of one or more of the associated listed items.
[0055] As used herein, the common abbreviation "e.g.", which
derives from the Latin phrase "exempli gratia," may be used to
introduce or specify a general example or examples of a previously
mentioned item, and is not intended to be limiting of such item. If
used herein, the common abbreviation "i.e.", which derives from the
Latin phrase "id est," may be used to specify a particular item
from a more general recitation.
[0056] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the invention. As used herein, the singular forms "a", "an" and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise.
[0057] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which this
invention belongs. It will be further understood that terms, such
as those defined in commonly used dictionaries, should be
interpreted as having a meaning that is consistent with their
meaning in the context of the relevant art and will not be
interpreted in an idealized or overly formal sense unless expressly
so defined herein.
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