Note: Descriptions are shown in the official language in which they were submitted.
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"AIR TO AIR HEAT EXCHANGER"
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BACKGROU~D OF THE INVENTION
This invention relates to an air to air heat
exchanger and particularly to the structure and construc-
tion of a frame and panels therefor.
Heat exchangers of various types and construc-
tions have been manufactured for many years but have
recently become more important in view of increasing fuel
costs. In many cases heat exchangers can be manufactured
of a specific size and construction for a particular end
use and can be shipped and installed as a single unit.
ExampLes of such arrangements are domesti~ heat exchang-
ers where the size of unit necessary for even larger
houses is relatively small and a single design can sati~-
fy many different housing requirements. A further
example is provided by wall mounted units which can be
used in livestock barns and the like and again a single
unit can be used to satisfy many different requirements
with further wall mounted units being applied if neces-
sary at different locations in the barn.
Larger systems for example for apartments,
workshops and hotel or conference facilities often
require a central system which is ducted to various dif-
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ferent locations in ~he building. In such a case the
unit may be of a size which is inconvenient to ship in
assembled f3rm and in addition the large variations in
requirements may make a single design unsatisfactory
since it cannot accommodate the different possible end
uses.
SUMMARY OF THE INVENTION
It is one obj~ct of the present invention,
therefore, to provide an improved structure of air ~o air
heat exchanger which enables ready assembly of the heat
exchanger and variations in the construction thereof to
accommodate different design requirements.
According to the invention, therefore, there is
provided an air to air heat exchanger comprising a frame
structure including a plurality of straight frame ele-
ment~ and me3ns for interlocking the frame elements at
right angle corners to form a frame defining on each side
thereof, a plurality of separate rectangular faces, each
bounded by four such frame elements and defining a
plurality of cells each having six such faces, a core
structure defining first and second separate air paths
therethrough in heat exchanging air impervious relation-
ship, said core structure being mounted in at least one
of said cells and a plurality of panels each adapted to
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fit sealingly in a single face of said frame structure,
at least four of said panels each having an opening
therein whereby the our panels form respectively an
inlet and outlet for said first path and an inlet and
outlet for said second path.
With the foregoing in view, and other advan-
tages as will become apparent to those skilled in the art
to which this invention relates as this specification
proceeds, the invention is herein described by reference
to the accompanying drawings forming a part hereof, which
includes a description of the best mode known ~o the
applicant and of the preferred typical embodiment of the
principles of the present invention, in which:
DESCRIPTION OF THE ~R~WINGS
Figure 1 is an isometric view showing the
exterior of a heat exchanger according to the invention.
Figure 2 is a longitudinal cross sectional view
of the heat exchanger o Figure 1.
Figure 3 is a cross sectional view on an
enlarged scale of a junction ~etween two frame elements
and the associated panel therebe~ween.
Figure 4 is a transverse cross section view of
a heat exchanger of si~ilar construction to that of
Figure 1 but of increased width to provide greater air-
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flow capacity.
In the drawings like characters of reference
indicate corresponding p~r~s in the different figures.
DETAILED D~SC~PTION
A heat exchanger comprises a generally rectang-
ular frame formed to define a plurality of individual
cells. Specifically the frame structure is formed from a
plurality of frame elements lO arranged to interlock at
right angle corner members 11 one of which is shown in
more detail in Figure 3. This arrangement forms a
rectangular cell construction with three columns of four
cells each making a total of twelve cells each of which
is a cube as all of the frame elements lO are of the same
length.
Each of the rame elements comprises a square
section tube cut from an extrusion preferably of aluminum
or similar material. The corner members 11 are of a
commercially available type which defines a central block
12 against which the ends of the tubes lO abut together
with a number of arms 13 each of which projects into a
respective tube or frame element as a press fit or as a
lock fit to hold the frame elements mutually at right
angles. The corner members 11 are available with varying
numbers and arrangements of arms as required for the
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diferent locatiorls in the frame as it will apparent from
a simple study of the s~ructure. In some cases a simple
plastics extension arm 13 can be suitable which is simply
press fit into the tubular frame element. However, more
rigid structures can be obtained by a system commercially
available from Beautiline Systems Ltd. of Downsview
Ontario by which rotation of a tube element through 90
causes a locking movement so that the tubular element is
retained more rigidly on ~he corner member ll.
In order to complete the heat exchanger and the
frame structure, a plurality of panels is arranged with
each fitted in a face of the cell defined by four such
frame elements. Each panel has a square ~ront face
generally indicated at 14 and four flanges 15 which are
turned at right angles to the front face so as to extend
rearwardly into the area between the frame elements. The
flanges 15 as shown best in Figure 3 are screwed to the
frame elements by screws 16 which pass through the flange
and engage a drilled hole in the frame element 10 partic-
ularly on an inside face of the square tubing indicated
at lOl. Between the flange 15 and the face 101 is mount-
ed a gasket 17 of thin rubber or the like by which the
structure is given resilience and by which vibration
between the different components is dampedO Various
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different types of panels are provided as will be ex-
plained hereinaf~er but each is mounted in the manner
shown in most detail in Figure 3.
A basic panel indicated at 18 cornprises simply
a plain sheet which closes the area between the frame
elements. A second type o panel indicated at 18 in-
cludes an access door. The acce~s door is square and
-only slightly smaller than the basic panel with ou~side
flanges 19 (see Figure 4) for cooperating with inner
flanges 20 of the access door panel 21. The access door
includes a handle 22 which can be actuated to lock or
release the access door and pivots on pins 23 arranged at
the bottom of ~he door for cooperation with side edges of
the access door panel portion 21.
A third type of panel is indica~ed at 24 in
Figures 1 and 2 and comprises an inlet panel having
flanges ~or a~tachment to a square feed duct particularly
of clean outside air. Thus the panel 24 comprises the
flange 15 as previously explained, a narrow surrounding
strip portion 25 at right angles to the flange 15 and an
upstanding flange 26 for receiving in close fit the walls
of a square duct 27. The remainder of the panel central-
ly of the 1anges 26 is of course open as indicated at 28
so that the inlet air from the duct 27 can pass into the
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heat exchanger~
A further type of panel indicated at 29 is of
basically the same construction as the panel 24 but also
it includes a filter screen 30 mounted in an area between
the flanges 15 for filtering stale exhaust air taken from
inside the building through a duct 31, the filter acting
to extract impurities from the air prior to passage of
the air through the core as is described hereinafter to
avoid deposit of the impurities on the core.
A further type of panel is indicated at 32 and
carries a fan 33 and motor 34. The fan as shown in the
top left hand and bottom left hand cells of Figure 2
comprises a centrifugal type fan of generally convention-
al design and shown schematically. The panel 32 provides
a flange 26A similar to the flange 26 of the panel 24 for
receiving an outlet duct 35. Inside the flange 26A, the
panel provides an inwardly extending surrounding rim
portion for receiving a mounting flangè 36 of the fan
housing with a gasket 37 between the flange 36 and the
inwardly projecting surrounding rim portion indicated at
38, the gasket providing sound deadening and vibration
dampening properties. The fan housing is therefore
mounted wholly upon the panel 32 and in turn the motor 34
is support upon a bracket 38 schematically indicated and
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attached to the fan housing. The fan is driven by a belt
39 from the motor so that air drawn in through the ends
of the fan axlally thereto is ejected through the opening
defined inside the surrounding rim portion 38 into the
duct 35.
A yet further panel type generally indicated at
40 in Figure 2 comprises a motoriæed damper panel which
carries moveable flaps 41 which can be turned from an
open position indicated generally at 42 to a closed posi-
tion indicated generally at 43. These flaps can be
actuated by a suitable motor mechanism (not shown).
A still further panel type indicated at 44
comprises a back draft damper in which a plurality of
flaps 45 depend downwardly from hinge points 46 so that
they can be opened by movement of the air in an intended
direction and are closed by movement of air in the oppo-
site direction t~ pre~ent a back drat. It will be
appreciated that the panels 40 and 44 are of course
constructed in the same manner a~ ~he basic panels ~ith
the necessary interconnections and support for the flaps
as will be apparent to one skilled in the art.
Yet further panels are indicated at 47 and 48
and comprise respectively water injection panels and
drain panels. A construction of the basic panel is as
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g
r.
previously described. The water injection panel 47
proYides a manifold 49 for attachment to a hose supply 50
of wat.er or suitable cleaning agent and a plurality of
nozzles 51 for directing the water onto the core general-
ly indicated at 52. The drain panel 48 has a central
opening 53 and is indented slightly so that water runs
from the core to the opening 53 for suitable collection.
The core fills the two central cells and is of
the type described in more detail in U.S. Patent
4,512,392 (Benning and Van Ee), (Canadian Patents
1,177,821 and 10179,323). The core is formed from Coro-
plast (trademark) sheets which are a polypropylene extru-
sion shown best in Figure 4. Each extrusion generally
indicated at 54 comprises a pair of plastic sheetq 55, 56
interconnected by transverse dividers 57 forming small
square cell~ longitudinally of the sheet through which
air can pass. Each extrusion 54 is separated from a next
adjacent extrusion by spaces 58 so that air can pass
between the sheet 56 of a first extrusion and the ad]a-
~0 cent sheet lndicated at S5A of the next extrusion in the
construction of the core. As shown in Figures 2 and 4,
the core is constructed with the extrusions arranged in
vertical planes and so that the small cells run in a
horizontal direction.. Thus the wider areas defined
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between the widely spaced sp~cers 58 run in a vertical
direction also divided by the vertical planes of the
extrusions. As shown best in Figure 2, the ~pacers 58
are arranged only at widely spaced points for example at
the extreme edges of the core and possibly with one addi-
tional space centrally depending upon strength and design
requir~ments. t
In operation of the core shown par~icularly in
Figure 2, air is drawn from outside of the building that
is clean cold air through the duct 27 downwardly into the
upper right hand cell through the normally open baffle
plate 42 and into the small cells of the core. The
normally closed baffle plate 43 prevents the air from
passing urther downwardly so the air has to turn through
a right angle into the core as indicated by the arrow 60.
Downstream of the core, the air is confined by the plane
panels 17 to turn downwardly as indicated by the arrow 61
to the fan 33 which causes the movement of the air in the
path as described and ejects the air into the duct 35 for
communication into the building through conventional duct
work.
An exhaust path of air under a motor force from
the fan 33 in the upper left hand cell moves from the
duct 31 through the filter 30 and through the back draft
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damper 44 to turn as indicated at 62 into the wider
channels of the ~ore~ After moving vertically through
the core, the air turns as indicated at 63 toward the fan
33 for ejection into the duct 35.
In order to provide de-icing of the core, the
baffles 42 and 43 can be operation for example by a timer
so that when a de-icing cycle is required, the baffle 42
is closed and the baffle 43 opened so that warm exhaust
air is drawn through the core in both paths of the core
as explained in more detail in the above Patents.
The above layout of the fans and various panels
is of course only one possible design. It will be
appreciated that, in accordance with requirements of the
ducting and necessary airflows, the layout can be modi~
fied or enlarged as required simply by locating the
various panel types at different positions in the frame
construc~ion.
The construction of frame formed by the frame
elements and panels can therefore be supplied in
assembled form or as a kit of parts for assembly on site.
In addition the construction can be specifically tailored
to requirements with a design being provided either by
the supplier or by a user.
Since various modifications can be made in my
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inven~ion as hereinabove described, and many apparently
widely different embodiments of same made within the
spirit and scope ~f the claims without departing from
such spirit and scope, it is intended that all matter
contained in the accompanying specification shall be
interpreted as illustrative only and not in a limiting
sense.
