Note: Descriptions are shown in the official language in which they were submitted.
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_late Heat Exchanger
This invention relates to a plate heat exchanger, which
comprises a plurality of plates arranged to the side of each
other and each consisting of two metal sheets, which are welded
5 one to the other along two parallel edges cmd have longitudinal
bulgings in parallel with said edges. The present invention has
the object to produce a plate heat exchanger where the medium
flowing within the plate is guided in a direction in parallel
with the extension of the bulgings and back in the same direction.
10 This arrangement implies the further gain that substantially all
surfaces of the plates flown through by a medium participate in
the heat exchange. This is not the case, for example, when at
one end of the plate a box is used for turning the medium flowing
through the plates.
In general terms, the present invention provides a plate
heat exchanger comprising a plurality of plates, which are ar-
ranged to the side of each other and each of which consists of
two metal sheets, which are welded one to the other along two
parallel ed~es and are corrugated forming longitudinal bulgings
20 in parallel with said edges, whereby longitudinal passages are
formed in the plates/ characterized in that each plate at one end
is formed with a turning zone in that the bulgings in pairs meet
in such a manner, that in the sheet plane two outermost bulgings
meet along a semicircle line, thereafter the two bulgings next
25 to the outermost ones, a.s.o., and the number of hulgings is an
integer number, whereby the one half of the number of passages
of each of the parallel plates are connected to a common maniEold
and the second half of the number of passages are connected to a
common collecting main. The bulgings connected in pairs are
30 either symmetrical in cross-sectional shape and reversed one
relative to the other.
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An embodiment of the invention is described in the fol-
lowing,with reference to the accompanying drawings, in which
Fig. 1 is a perspecti~e view seen obliquely from below of
four plates with associated intakes, the casing about
the heat exchanger being omitted,
Fig. 2 is a lateral view on an enlarged scale of the plates
seen against the edge joints of the plates,
Fig. 3 is a section along the line III~-III in Fig. 2 and,
thus, a horizontal view of a metal sheet comprised
in a plate.
Fig. 1 thus, shows in a perspective way four plates, which
are arranged to the side of each other and provided with an in-
take. The plates 1 at the embodiment shown are four in number
and assembled of two metal sheets 2 and 3 so as to Eorm a hollow
flow body, see Fig. 2. Each plate has four passages ~, 5, 6 and
15 7. At the upper end of the plates a turning zone is formed so
that the passage ~ turns into the passage 7, and the passage 5
turns into the passage 6. The design of the passages will be-
come apparent in greatex detail from the following. At the
lower edge of the plates a distribution connecting piece 8 is
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attached, wi hin which a partition sheet 9 is located to s~pa-
rate the passages 4 and 5 from the passages 6 and 7. A medium
is hereby caused to flow into the plates according to arrow 10
and out of the plates according to arrow 11. In Fig. 1 the dist-
ribution connecting piece 8 is shown on an enlarged scale rela-
tive to the plates in order to simplify the illustration. The
length of the plates 1, of course, can be varied entirely as
desired in respect of the size of the heat surfaces. The second
medium participating in the heat exchange flows between the
plates 1, for example according to arrow 12. The flow path may
also be from above according to arrow 13 and thereafter ou~ward
at the arrows 14 and 15. ~ casing of sheet metal`is then placed
about the`plate package with an inlet provided a~ the upper edge
and one or several outlets provided close to the areas marked
1S by the arrows 14 and 15.
Figs 2 and 3 illustrate the structure of the plates and of
the metal sheets constituting the same. Fig. 3 is a section a-
long the line III-III in Fig. 2 and, thus, may be said to illu-
strate a metal sheet 3 seen ~rom the inside. The metal sheet
has longltudi~al bulgings 16, 17, 18 and 19, which may consist
o valleys o symm~tric shape, ~or example a portion of an arc.
~n Figs 2 and 3 a special shape is shown where the valle~s have
a cross-~ectional shape resembling half a pear, see the dashed
lines 20. This shape, thuA, is asymmetrlc relative to a central
line in the valley. In order to render it possible, for example,
for the passages 16 and 19 to meet in the turning zone, i.e.
at the upper end of the plates, the asymmetric shape for the
passages 16 and 19 must be identical but reversed, as also
appears from Fig. 3.
The cross-sectional shape of the valley 17 is equal but re-
versed to that o the valley 16, and the cross-sectional shape
or the valley 18 is reversed relative to the cross-sectional
shape ~or the valley 17. A cross-section along the line II-II
in Fig. 3 thereby yields the dashed lines in the upper part o~
Fig. 2 which are designated by 20 in order to make it understood
that they are in agreement with the dashed lines 20 in Fig. 3O
In Fig. 3, thus, an underlying metal sheet with the valleys 16-
19 ls shown. In order to obtain a plate, an overlying me~al
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sheet formed with corresponding valleys is placed thereon. When
the metal sheets are~positioned one against the other, the
valleys are closed and form passages. In each plate, thus, our
passages 4-7 according to Fig. 1 are formed. The cross~sectio-
nal shape of the passages in the turning zone is apparent romthe dashed lines in the upper part of Fig. 2.
In ~ig. 2, the numeral 21 designates a sheet metal casing
about the plate package, and in said casing the medium is inclu-
ded whith flows about and between the plates.
The distribution connecting piece 8 is shown in ~ig t 3 by
a cross-section through the lateral wall~ and also a cross-~ec-
tion through the partition wall 9. For connecting the side walls
in the distribution connecting piece 8 to the plates, the lower
; edges of the plates have been flattened, so that a cross-section
through the plate has V-shape. Said V-shape 22, which appears
from Figs 1 and 2, implies that the plates have a V-shaped open-
ing with straight edges. The sides 8 are cut open to correspond-
ing V-shape, so that "teeth" 23 are formed which are welded on
corresponding edges of the plates. The walls 8 preferably aLe
designed with substantial thiakness, and in the "teeth" 23 re-
cesses 24 with corresponding V-shape are made, so that an upright
edge,25 extending in V-shape is formed. Said edge 25 abuts the
ree edge o the plates, and oW~n~ to the edge 25 projecting
rom the side 8 the po~sibility o welding to the lateral edge
of the plate is improved~ The plates in general are ~ointed
all about along the edges 26.
The structure has a good strength, and high temperature di-
ferences can be permitted. The plates bend only slightly, and
attachments in turning boxes or the like are not afected.
The 10w unction of the medium 10wing in the plates is
shown in Fig. 1~ The medium flows in at arrow 10, is distributed
in the passages 4 and 5, flows upward to the upper end of the
plates, turns in the so-called turning zone, flows back in the
passages 6 and 7 and out through the distribution connecting
piece 8 according to arrow 11. See also Fig. 3. ~he medium flow-
ing outside the plates can be guided in that a gasket strip, or
example of teflon, is laid in between the outer surfaces o two
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plates along the valley line between the passages 5 and G,
i.e. between the valleys 17 and 18. ~ereby a pure countercur-
rent between tha media can be obta.ned.
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