| |
| United States Patent
|
6,988,545 |
| Good |
January 24, 2006 |
Heat exchanger systems
Abstract
A heat exchanger system, for transferring waste heat from a
stream of exhaust air produced in a dryer to a stream of fresh air
directed to flow into the dryer, including a retriever, or
retriever, comprising an array of a plurality of substantially
mutually parallel, substantially vertical heat-transfer conduits
having square cross-sections arrayed in alternating staggered rows
relative to a perpendicular to the general direction of the flow of
the stream of fresh air into the dryer, wherein each heat-transfer
conduit is oriented to have one corner facing in the general
direction of the flow of the stream of fresh air into the dryer.
Associated structure for housing the retriever, supporting it in the
flow of fresh air, and directing dryer exhaust air into the
heat-transfer conduits is also included. The heat exchanger system
is adaptable to a wide variety of dryers, and may be built-in.
| Inventors: |
Good; Harold Max
(Phoenix, AZ) |
| Appl. No.:
|
10/766,453 |
| Filed: |
January 27, 2004 |
Related U.S. Patent Documents
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Application Number |
Filing Date |
Patent Number |
Issue Date |
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60443212 |
Jan., 2003 |
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| Current U.S.
Class: |
165/173 ;
165/177 |
| Current
International Class: |
F28F
1/04 (20060101) |
| Field of
Search: |
165/172,173,175,177,110,910,151,153 34/86 |
References Cited
[Referenced By]
U.S. Patent
Documents
Primary Examiner: Walberg; Theresa J.
Attorney, Agent or Firm:
Stoneman Law Offices, Ltd. Stoneman; Martin L. Erlick;
Benjamin K.
Parent Case Text
The present application is related to and claims priority from prior
provisional application Ser. No. 60/443,212 filed Jan. 27, 2003,
entitled "HEAT EXCHANGE SYSTEM", the contents of which are
incorporated herein by this reference and are not admitted to be
prior art with respect to the present invention by the mention in
this cross-reference section. The present application is also
related to applicant's U.S. Pat. No. 4,676,007 issued Jun. 30, 1987,
entitled "HEAT EXCHANGER FOR GRAIN ELEVATORS OR BINS" and
applicant's U.S. Pat. No. 4,821,428 issued Apr. 18, 1989, entitled
"HEAT EXCHANGER FOR GRAIN ELEVATORS OR BINS", the contents of which
are herein incorporated by reference as supporting background and
are not admitted to be prior art with respect to the present
invention by their mention in this section.
Claims
What is claimed is:
1. A heat exchanger system, relating to transferring waste heat from
a stream of exhaust air produced in a dryer to a stream of fresh air
directed to flow into the dryer, comprising: a) at least one heat
transferor structured and arranged to substantially convectively
transfer the waste heat to the stream of fresh air, b) wherein said
at least one heat transferor comprises at least one array structured
and arranged to array substantially vertical, substantially mutually
parallel plurality of heat-transfer conduits adapted to internally
conduct segregated portions of the stream of exhaust air, c) wherein
at least one heat-transfer conduit of said plurality of
heat-transfer conduits comprises at least one thermally-conductive
conduit wall structured and arranged to conduct heat from the
segregated portions of the stream of exhaust air to the stream of
fresh air, d) wherein said at least one heat-transfer conduit
comprises at least one substantially square cross-section; and e)
wherein said at least one substantially square cross-section is
oriented to have one corner of said at least one substantially
square cross-section facing the general direction of flow of the
stream of fresh air through said at least one heat transferor.
2. The heat exchanger system according to claim 1, further
comprising the dryer.
3. The heat exchanger system according to claim 1, wherein said at
least one array comprises staggered alternating rows of said at
least one heat-transfer conduit comprising said at least one
substantially square cross-section oriented to have one corner of
said at least one substantially square cross-section facing the
general direction of flow of the stream of fresh air through said at
least one heat transferor.
4. The heat exchanger system according to claim 1, wherein said at
least one array comprises at least five staggered alternating rows.
5. The heat exchanger system according to claim 1, wherein said at
least one array has at least one dimensional relationship
comprising: a) external side width of said at least one
substantially square cross section of said at least one
heat-transfer conduit; and b) uniform side-to-side spacing apart of
said plurality of said heat-transfer conduits of about one-half of
said external side width of said at least one square cross section
of said at least one heat-transfer conduit.
6. The heat exchanger system according to claim 5, wherein said
external side width is about one-and one-half inches.
7. The heat exchanger system according to claim 1, wherein said at
least one thermally-conductive conduit wall comprises at least one
conduit wall about 0.018'' thick.
8. The heat exchanger system according to claim 1, wherein said at
least one thermally-conductive conduit wall comprises aluminum.
9. The heat exchanger system according to claim 1, wherein said
heat-transferor further comprises at least one side constraint
structured and arranged to constrain the flow of the fresh air over
said heat-transfer conduits to move between first and second
opposing sides of said heat-transferor.
10. A heat exchanger system, for transferring waste heat from a
stream of exhaust air produced in a dryer to a stream of fresh air
directed to flow into the dryer, comprising: a) at least one
retriever comprising at least one array of at least one plurality of
substantially mutually parallel, substantially vertical
heat-transfer conduits having square cross-sections arrayed in
alternating staggered rows relative to a perpendicular to the
general direction of the flow of the stream of fresh air into the
dryer, wherein each heat-transfer conduit is oriented to have one
corner facing in the general direction of the flow of the stream of
fresh air into the dryer; and b) at least one structure adapted to
support said at least one array of said at least one plurality of
heat-transfer conduits transverse to the flow of the stream of fresh
air into the dryer.
11. The heat exchanger system according to claim 10, further
comprising at least one structure for assisting receiving the stream
of exhaust air internal to said at least one heat-transfer conduit
of said at least one retriever.
12. The heat exchanger system according to claim 10, further
comprising said at least one retriever adapted to be integrated with
at least one pre-existing particular dryer, wherein said at least
one retriever further comprises said at least one structure
integrated with said at least one array of heat-transfer conduits.
13. The heat exchanger system according to claim 10, further
comprising said at least one retriever integrated with at least one
particular dryer.
14. A heat exchanger system, relating to transferring waste heat
from a stream of exhaust air produced in a dryer to a stream of
fresh air directed to flow into the dryer, comprising the steps of:
a) pre-configuring, responsive to customer requirements, at least
one retriever comprising at least one array of at least one
plurality of substantially mutually parallel, substantially vertical
heat-transfer conduits having square cross-sections arrayed in
alternating staggered rows relative to a perpendicular to the
general direction of the flow of the stream of fresh air into the
dryer, wherein each heat-transfer conduit is oriented to have one
corner facing in the general direction of the flow of the stream of
fresh air through said at least one retriever.
15. The heat exchanger system according to claim 14, wherein the
step of pre-configuring comprises the step of determining at least
one size requirement for said at least one array.
16. The heat exchanger system according to claim 15, wherein the
step of pre-configuring comprises the step of perforating at least
one plate with at least one pattern of a plurality of square
perforations in staggered rows, each square perforation oriented
cornerwise to the general direction of flow of the fresh air over
said at least one plate, responsive to said at least one size
requirement.
17. The heat exchanger system according to claim 16, further
comprising the step of attaching said plurality of heat transfer
conduits to said at least one plate, wherein each said heat transfer
conduit of said plurality of heat transfer conduits is aligned and
oriented to one perforation of said plurality of perforations.
18. The heat exchanger system according to claim 14, further
comprising the step of attaching structural elements to at least
said at least one plate, wherein said structural elements are
structured and arranged to at least maintain structural integrity of
said retriever.
19. The heat exchanger system according to claim 14, further
comprising the step of installing said retriever in at least one
dryer.
20. A heat exchanger system, relating to transferring waste heat
from a stream of exhaust air produced in a dryer to a stream of
fresh air directed to flow into the dryer, comprising: a) heat
transfer means for substantially convectively transferring the waste
heat to the stream of fresh air, b) wherein said heat transfer means
comprises array means for arraying at least five rows of staggered
alternating substantially vertical, substantially parallel
heat-transfer conduit means for internally conducting segregated
portions of the stream of exhaust air, c) wherein said heat-transfer
conduit means comprise thermally-conductive conduit wall means for
conducting heat from the segregated portions of the stream of
exhaust air to the stream of fresh air, d) wherein said
heat-transfer conduit means comprises fluid-dynamic means for
influencing dynamics of the fresh air, and wherein said
fluid-dynamic means comprises heat-transfer conduit means having
substantially square cross-sections; and e) the dryer; f) wherein
said substantially square cross-sections are oriented to have one
corner of said substantially square cross-sections facing the
general direction of flow of the stream of fresh air through said
heat transferor.
Description
BACKGROUND
This invention relates to heat exchanger systems. More particularly,
this invention relates to providing heat exchanger systems for
improved drying of agricultural products, for example, prunes, and
fabrics, for example laundry, using a system of heat recovery.
Typically, tremendous amounts of heat energy are wasted in
conventional crop drying techniques. Conventional drying processes
use large quantities of energy to heat cold ambient air to the
temperature required to dry the crop. Much of this heat/energy is
wasted by the direct discharge of the hot exhaust air exiting the
dryer. FIG. 1 is a diagrammatic sectional view of a conventional
crop dryer 104. Typically, crop dryer 104 comprises an enclosed
tunnel 101 through which heated air 103 passes to dry crop 110, as
shown for, typically, the drying of prunes. In existing systems,
energy is wasted by directly discharging moist, heated moist, heated
exhaust air 105 from enclosed tunnel 101, as shown. Users of
commercial and household laundry dryers suffer from the same waste
heat losses. A need exists for a system that utilizes the large
amount of thermal energy typically discarded with the exhaust air as
waste.
OBJECTS OF THE INVENTION
A primary object and feature of the present invention is to provide
heat exchanger systems to address the above-mentioned problems and
to meet the above-mentioned needs.
A further primary object and feature of the present invention is to
provide heat exchanger systems adaptable to a variety of crop
dryers, laundry dryers, and other devices producing dryer exhaust
containing waste heat.
A further primary object and feature of the present invention is to
provide heat exchanger systems having heat-transfer conduits having
large heat-transfer surface areas
A further primary object and feature of the present invention is to
provide heat exchanger systems having and arrangement of square
heat-transfer conduits having effective flow characteristics for
drying applications.
A further primary object and feature of the present invention is to
provide such a system that is efficient, inexpensive, and handy.
Other objects and features of this invention will become apparent
with reference to the following descriptions.
SUMMARY OF THE INVENTION
In accordance with a preferred embodiment hereof, this invention
provides a heat exchanger system, relating to transferring waste
heat from a stream of exhaust air produced in a dryer to a stream of
fresh air directed to flow into the dryer, comprising: heat transfer
means for substantially convectively transferring the waste heat to
the stream of fresh air, comprising array means for arraying
substantially vertical, substantially parallel heat-transfer conduit
means for internally conducting segregated portions of the stream of
exhaust air, wherein such heat-transfer conduit means comprise
thermally-conductive conduit wall means for conducting heat from the
segregated portions of the stream of exhaust air to the stream of
fresh air, wherein such heat-transfer conduit means comprise
fluid-dynamic means for influencing dynamics of the fresh air,
further wherein such fluid-dynamic means comprises heat-transfer
conduit means having substantially square cross-sections; and
structure means for structuring a relationship between such heat
transfer means and the dryer.
Moreover, it provides such a heat exchanger system, wherein such
structural means comprises: base support plate means for supporting
such heat transfer means; top support plate means for supporting
such heat transfer means; and interconnection means for
interconnecting at least two of such heat transfer means, such base
support plate means, such top support plate means, and the dryer.
Additionally, it provides such a heat exchanger system, wherein such
fluid-dynamic means further comprises heat-transfer conduit means
oriented to have one corner of such square cross-section facing the
general direction of flow of the stream of fresh air through such
heat transfer means. Also, it provides such a heat exchanger system,
wherein such array means comprises staggered alternating rows.
In addition, it provides such a heat exchanger system, wherein such
array means has dimensional relationship means comprising: external
side width of such square cross section of such heat-transfer
conduit means; and uniform side-to-side spacing apart of about
one-half of such external side width. And, it provides such a heat
exchanger system, wherein such thermally-conductive conduit wall
means comprise conduit walls about 0.018'' thick. Further, it
provides such a heat exchanger system, wherein such
thermally-conductive conduit wall means comprise aluminum. Even
further, it provides such a heat exchanger system, wherein such
heat-transfer means further comprises side constraining means for
constraining the flow of the fresh air over such heat-transfer
conduit means to move between first and second opposing sides of
such heat-transfer means.
In accordance with another preferred embodiment hereof, this
invention provides a heat exchanger system, related to transferring
waste heat from a stream of exhaust air produced in a dryer to a
stream of fresh air directed to flow into the dryer, comprising: at
least one heat transferor structured and arranged to substantially
convectively transfer the waste heat to the stream of fresh air,
comprising at least one array structured and arranged to array
substantially vertical, substantially mutually parallel plurality of
heat-transfer conduits adapted to internally conduct segregated
portions of the stream of exhaust air, wherein at least one
heat-transfer conduit of such plurality of heat-transfer conduits
comprises at least one thermally-conductive conduit wall structured
and arranged to conduct heat from the segregated portions of the
stream of exhaust air to the stream of fresh air, wherein such at
least one heat-transfer conduit comprises at least one fluid-dynamic
shape for influencing dynamics of the fresh air, further wherein
such fluid-dynamic shape comprises at least one substantially square
cross-section; and at least one structure configured to maintain at
least one structural relationship between such heat transferor and
the dryer.
Moreover, it provides such a heat exchanger system, wherein such
structure comprises: at least one base support plate structured and
arranged to support lower ends of such heat transferor; at least one
top support plate structured and arranged to support upper ends of
such heat transferor; and at least one interconnector structured and
arranged to interconnect at least two of such heat transferor, such
at least one base support plate, such at least one top support
plate, and the dryer. Additionally, it provides such a heat
exchanger system, wherein such at least one fluid-dynamic shape
further comprises at least one heat-transfer conduit oriented to
have one corner of such square cross-section facing the general
direction of flow of the stream of fresh air through such heat
transferor. Also, it provides such a heat exchanger system, wherein
such at least one array comprises staggered alternating rows.
In addition, it provides such a heat exchanger system, wherein such
at least one array has at least one dimensional relationship
comprising: external side width of such at least one square cross
section of such at least one heat-transfer conduit; and uniform
side-to-side spacing apart of such plurality of such heat-transfer
conduits of about one-half of such external side width of such at
least one square cross section of such at least one heat-transfer
conduit. And, it provides such a heat exchanger system, wherein such
external side width is one-and one-half inches. Further, it provides
such a heat exchanger system, wherein such at least one
thermally-conductive conduit wall comprises at least one conduit
wall about 0.018'' thick. Even further, it provides such a heat
exchanger system, wherein such at least one thermally-conductive
conduit wall comprises aluminum. Moreover, it provides such a heat
exchanger system, wherein such heat-transferor further comprises at
least one side constraint structured and arranged to constrain the
flow of the fresh air over such heat-transfer conduits to move
between first and second opposing sides of such heat-transferor.
In accordance with another preferred embodiment hereof, this
invention provides a heat exchanger system, relating to transferring
waste heat from a stream of exhaust air produced in a dryer to a
stream of fresh air directed to flow into the dryer, comprising: a
retriever comprising at least one array of at least one plurality of
substantially mutually parallel, substantially vertical
heat-transfer conduits having square cross-sections arrayed in
alternating staggered rows relative to a perpendicular to the
general direction of the flow of the stream of fresh air into the
dryer, wherein each heat-transfer conduit is oriented to have one
corner facing in the general direction of the flow of the stream of
fresh air into the dryer; and at least one structure adapted to
support such at least one array of such at least one plurality of
heat-transfer conduits transverse to the flow of the stream of fresh
air into the dryer.
Additionally, it provides such a heat exchanger system, further
comprising at least one structure for assisting receiving the stream
of exhaust air internal to such at least one heat-transfer conduit
of such retriever. Also, it provides such a heat exchanger system,
further comprising at least one retriever adapted to be integrated
with at least one pre-existing particular dryer, wherein such at
least one retriever further comprises such at least one structure
integrated with such at least one array of heat-transfer conduits.
In addition, it provides such a heat exchanger system, comprising
such at least one retriever integrated with such at least one
particular pre-existing dryer. And, it provides such a heat
exchanger system, further comprising such at least one retriever
integrated with at least one particular dryer.
In accordance with another preferred embodiment hereof, this
invention provides a heat exchanger. system, relating to
transferring waste heat from a stream of exhaust air produced in a
dryer to a stream of fresh air directed to flow into the dryer,
comprising the steps of: pre-configuring, responsive to customer
requirements, at least one retriever comprising at least one array
of at least one plurality of substantially mutually parallel,
substantially vertical heat-transfer conduits having square
cross-sections arrayed in alternating staggered rows relative to a
perpendicular to the general direction of the flow of the stream of
fresh air into the dryer, wherein each heat-transfer conduit is
oriented to have one corner facing in the general direction of the
flow of the stream of fresh air through such retriever.
Further, it provides such a heat exchanger system, wherein the step
of pre-configuring comprises the step of determining at least one
size requirement for such at least one array. Even further, it
provides such a heat exchanger system, wherein the step of
pre-configuring comprises the step of perforating at least one plate
with at least one pattern of a plurality of square perforations in
staggered rows, each square perforation oriented cornerwise to the
general direction of flow of the fresh air over the plate,
responsive to such at least one size requirement. Even further, it
provides such a heat exchanger system, further comprising the step
of attaching such plurality of heat transfer conduits to such at
least one plate, wherein each such heat transfer conduit of such
plurality of heat transfer conduits is aligned and oriented to one
perforation of such plurality of perforations.
Even further, it provides such a heat exchanger system, further
comprising the step of attaching structural elements to at least
such at least one plate, wherein such structural elements are
structured and arranged to at least maintain structural integrity of
such retriever. Even further, it provides such a heat exchanger
system, further comprising the step of installing such retriever in
at least one dryer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic sectional view of a conventional crop
dryer.
FIG. 2 is a diagrammatic sectional view of a crop dryer utilizing a
heat exchanger system according to a preferred embodiment of the
present invention.
FIG. 3 is a perspective view in partial section illustrating a crop
dryer utilizing the heat exchanger system according to a preferred
embodiment of the present invention.
FIG. 4 is a perspective view of the heat exchanger system according
to the embodiment of FIG. 3.
FIG. 5A is a top view of the base plate of the heat-exchanging
retriever illustrating a typical layout of holes for receiving
heat-exchanging conduits according to the embodiment of FIG. 3.
FIG. 5B is a side view of a portion of the base plate of FIG. 5A, a
portion of a top plate, and a heat-transfer conduit connected there
between by end-flaring according to a preferred embodiment of the
present invention.
FIG. 6 is a side elevation diagrammatic view of a heat-exchanging
retriever adapted for use with a laundry dryer according to a
preferred embodiment of the present invention.
FIG. 7 is a flowchart of a heat exchanger system process according
to a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
FIG. 2 is a diagrammatic sectional view of crop dryer 104 utilizing
heat exchanger system 100 according to a preferred embodiment of the
present invention, as shown. Preferably, retriever 102 of heat
exchanger system 100 acts as a pre-heater, returning wasted heat
from a stream of moist, heated exhaust air 105 to the input stream
of fresh air 116 that then enters the crop dryer 104 as pre-heated
intake air 108, as shown (at least herein embodying heat transfer
means for substantially convectively transferring the waste heat to
the stream of fresh air; and at least herein embodying at least one
heat transferor structured and arranged to substantially
convectively transfer the waste heat to the stream of fresh air).
Preferably, burner 106 of crop dryer 104 adds thermal energy to the
pre-heated intake air 108 to achieve the temperature for the dryer
air 103 required to dry crop 110, as shown (at least one retriever
adapted to be integrated with at least one pre-existing particular
dryer; and at least herein embodying retriever integrated with said
at least one particular pre-existing dryer; and at least herein
embodying retriever integrated with at least one particular dryer).
Heat exchanger system 100 preferably returns much of the wasted heat
to crop dryer 104, as shown. Upon reading the teachings of this
specification, those with ordinary skill in the art will now
understand that, under appropriate circumstances, considering such
issues as dryer configuration, required flow rates, convenience,
economics, user preference, etc., other positions for retriever 102,
such as an external position connected by ductwork, variation of
position within crop dryer 104, etc., may suffice.
FIG. 3 is a perspective view in partial section illustrating crop
dryer 104 utilizing heat exchanger system 100 according to a
preferred embodiment of the present invention. Preferably, before
moist, heated exhaust air 105 is allowed to leave dryer system 100,
moist, heated exhaust air 105 enters retriever 102, preferably
containing an array of about 600 heat-exchanging conduits 112 about
six feet in length, as shown (at least herein embodying array means
for arraying substantially vertical, substantially parallel
heat-transfer conduit means for internally conducting segregated
portions of the stream of exhaust air; and at least herein embodying
at least one array structured and arranged to array substantially
vertical, substantially mutually parallel plurality of heat-transfer
conduits adapted to internally conduct segregated portions of the
stream of exhaust air). Walls of the heat-exchanging conduits 112
are heated as moist, heated exhaust air 105 is exhausted through
them into the environment as cooled exhaust air 114, as shown.
Preferably, fresh air 116 entering crop dryer 104 is pulled across
the exterior surfaces of the walls of the heated heat-exchanging
conduits 112, thereby producing pre-heated air 108 to reduce the
required energy input required at burner 106, as shown (at least
herein embodying thermally-conductive conduit wall means for
conducting heat from the segregated portions of the stream of
exhaust air to the stream of fresh air; and at least herein
embodying at least one thermally-conductive conduit wall structured
and arranged to conduct heat from the segregated portions of the
stream of exhaust air to the stream of fresh air). Upon reading the
teachings of this specification, those with ordinary skill in the
art will now understand that, under appropriate circumstances,
considering such issues as dryer configuration, type of crop or
material to be dried, temperature requirements, required flow rates,
convenience, economics, user preference, etc., other numbers of
heat-exchanging conduits 112 and other lengths of heat-exchanging
conduits 112 for retriever 102, such as longer or shorter
heat-exchanging conduits 112 adapted to a particular dryer
configuration or more or fewer heat-exchanging conduits 112 adapted
to flow rates and temperature requirements, etc., may suffice.
FIG. 4 is a perspective view of the heat exchanger system 100
according to the embodiment of FIG. 3. Preferably, a structure 120
and 126, such as rigid steel framing, supports retriever 102 in the
stream of fresh air 116, as shown (at least herein embodying
structure means for structuring a relationship between said heat
transfer means and the dryer; and at least herein embodying at least
one structure configured to structure a relationship between said
heat transferor and the dryer). Preferably, structure 120 includes
flow constraints 118 and 119, such as canvas sidewalls, as shown (at
least herein embodying side constraining means for constraining the
flow of the fresh air over said heat-transfer conduit means to move
between first and second opposing sides of said heat-transfer means;
and at least herein embodying at least one side constraint
structured and arranged to constrain the flow of the fresh air over
said heat-transfer conduits to move between first and second
opposing sides of said heat-transferor). Preferably, structure 126
includes a frame for receiving the retriever 102, as shown (at least
herein embodying structure means for structuring a relationship
between said heat transfer means and the dryer; and at least herein
embodying at least one structure adapted to support said at least
one array of said at least one plurality of heat-transfer conduits
transverse to the flow of the stream of fresh air into the dryer).
In an alternate embodiment, retriever 102 is preferably supported,
at least partially, by pre-existing structure of the crop dryer 104,
as shown in FIGS. 1 2 (at least herein embodying at least one
retriever adapted to be integrated with at least one pre-existing
particular dryer; and at least herein embodying retriever integrated
with said at least one particular pre-existing dryer; at least
herein embodying retriever integrated with at least one particular
dryer).
Preferably, some flow constraints are integral to the crop dryer
104, such as steel-framed pivoting canvas doors 122 which provides
crop 110 access to crop dryer 104 and directs air into retriever
102, as shown (at least herein embodying structure means for
structuring a relationship between said heat transfer means and the
dryer; and at least herein embodying at least one structure
configured to structure a relationship between said heat transferor
and the dryer). In some alternate embodiments, steel-framed pivoting
canvas doors 122 may be integral to structure 120, structure 126 or
to retriever 102 (at least herein embodying said at least one
structure integrated with said at least one array of heat-transfer
conduits). In such an alternate embodiment, the canvas is preferably
a PVC coated fabric having a substantially polyester plain weave
substrate. Upon reading the teachings of this specification, those
with ordinary skill in the art will now understand that, under
appropriate circumstances, considering such issues as dryer
configuration, available installation sites, type of crop 110 or
material to be dried, temperature requirements, required flow rates,
convenience, economics, user preference, etc., other adapted
structures for supporting the retriever 102 in the stream of fresh
air 116, such as more or less structure 120, adapted configurations
and sizes of flow constraints 118, 119, and 122, or various adapted
materials for the flow constraints 118, 119, and 122 or structure
120, etc., are included within various embodiments of the present
invention adapted to specific dryer-related requirements.
FIG. 5A is a top view of support plate 124 used as the base plate
124a and the top plate 124b of the heat-exchanging retriever 102
illustrating an exemplary layout and orientation of openings 113 for
receiving the array of heat-exchanging conduits 112 according to the
preferred embodiment of FIG. 3, as shown (at least herein embodying
base support plate means for supporting said heat transfer means;
and at least herein embodying top support plate means for supporting
said heat transfer means; and at least herein embodying at least one
base support plate structured and arranged to support lower ends of
said heat transferor; and at least herein embodying at least one top
support plate structured and arranged to support upper ends of said
heat transferor). Preferably, the array of heat-exchanging conduits
112 has staggered alternating rows of square heat-exchanging
conduits 112 each oriented to have a corner facing the general
direction of the flow of fresh air 116 through the retriever 102, as
shown (at least herein embodying fluid-dynamic means for influencing
dynamics of the fresh air, further wherein said fluid-dynamic means
comprises heat-transfer conduit means having substantially square
cross-sections; and at least herein embodying heat-transfer conduit
means oriented to have one corner of said square cross-section
facing the general direction of flow of the stream of fresh air
through said heat transfer means; and at least herein embodying
staggered alternating rows; and at least herein embodying at least
one fluid-dynamic shape for influencing dynamics of the fresh air,
further wherein said fluid-dynamic shape comprises at least one
substantially square cross-section; and at least herein embodying at
least one heat-transfer conduit oriented to have one corner of said
square cross-section facing the general direction of flow of the
stream of fresh air through said heat transferor; and at least
herein embodying at least one array of at least one plurality of
substantially mutually parallel, substantially vertical
heat-transfer conduits having square cross-sections arrayed in
alternating staggered rows relative to a perpendicular to the
general direction of the flow of the stream of fresh air into the
dryer, wherein each heat-transfer conduit is oriented to have one
corner facing in the general direction of the flow of the stream of
fresh air into the dryer). Preferably, the heat-exchanging conduits
112 are frictionally retained within support plates 124a and 124b by
end-flaring of the aluminum heat-exchanging conduits 112, as shown
in FIG. 5B (at least herein embodying the step of attaching said
plurality of heat transfer conduits to said at least one plate).
Structure 120 further supports plates 124a and 124b and
interconnects plates 124a and 124b in relation to the array of
heat-exchanging conduits 112, as shown (at least herein embodying
interconnection means for interconnecting said heat transfer means,
said base support plate means, and said top support plate means; and
at least herein embodying at least one interconnector structured and
arranged to interconnect said heat transferor, said at least one
base support plate, and said at least one top support plate; and at
least herein embodying wherein said at least one retriever further
comprises said at least one structure integrated with said at least
one array of heat-transfer conduits).
Preferably, heat-exchanging conduits 112 comprise uncoated, square
aluminum tubing having a wall thickness of about 0.018'', as shown
(at least herein embodying substantially square cross-sections; and
at least herein embodying wherein said thermally-conductive conduit
wall means comprise conduit walls about 0.018'' thick; and at least
herein embodying wherein said at least one thermally-conductive
conduit wall comprises at least one conduit wall about 0.018''
thick; and at least herein embodying wherein said
thermally-conductive conduit wall means comprise aluminum; and at
least herein embodying wherein said at least one
thermally-conductive conduit wall comprises aluminum). Preferably,
to improve the heat transfer efficiency of the system,
heat-exchanging conduits 112 are 11/2''.times.11/2'' square, as
shown (at least herein embodying external side width of said square
cross section of said heat-transfer conduit means). Preferably, the
spacing between heat-exchanging conduits 112 is one-half the width
of the sides of heat-exchanging conduits 112, or three-quarters of
an inch, as shown (at least herein embodying wherein said
heat-transfer conduits are uniformly spaced-apart three-quarters of
an inch side-to-side; and at least herein embodying uniform
side-to-side spacing apart of said plurality of said heat-transfer
conduits of about one-half of said external side width of said at
least one square cross section of said at least one heat-transfer
conduit; and at least herein embodying uniform side-to-side spacing
apart of about one-half of said external side width). Preferably,
the heat-exchanging conduits 112 are oriented such that one corner
faces the general direction of flow of fresh air 116 (at least
herein embodying heat-transfer conduit means oriented to have one
corner of said square cross-section facing the general direction of
flow of the stream of fresh air through said heat transfer means;
and at least herein embodying at least one heat-transfer conduit
oriented to have one corner of said square cross-section facing the
general direction of flow of the stream of fresh air through said
heat transferor). Applicant has found that, for such aluminum
heat-exchanging conduits 112, the above preferred wall thickness
provides an unexpectedly and exceptionally desirable combination of
heat exchange efficiency and structural stability. Upon reading the
teachings of this specification, those with ordinary skill in the
art will now understand that, under appropriate circumstances,
considering such issues as dryer configuration, temperature
requirements, required flow rates, material costs, material
heat-transfer rates, convenience, economics, user preference, etc.,
other materials, heat-exchanging conduit 112 sizes and relative
spacing, etc., may suffice.
FIG. 6 is a side elevation diagrammatic view of a heat-exchanging
system 600 showing retriever 602 pre-configured for use with a
laundry dryer 604. Laundry dryer 604 produces exhaust air 605, which
enters the heat-exchanging conduits 612 of retriever 602. Moist,
heated exhaust air 605 heats the heat-exchanging conduits 612 which
conduct the heat to outer surfaces of the heat-exchanging conduits
612, where the heat is transferred, mostly by convection, to the
input stream of fresh air 616. The input stream of fresh air 616 is
thereby pre-heated to become pre-heated air 608. Pre-heated air 608
is conducted to the dryer heater 606, which may include a burner or
heater coil or the like, where it is heated to become dryer air 603.
Upon reading the teachings of this specification, those with
ordinary skill in the art will now understand that, under
appropriate circumstances, considering such issues as dryer type,
matter to be dried, convenience, economics, user preference, etc.,
other retriever 602 configurations and applications, such as a model
configured for home laundry use, a model configured for drying died
fabrics, a model configured for timber drying, etc., may suffice.
Preferably, heat exchanger systems 100 and 600 are easily
pre-configured to be integrated to any one or more of a wide range
of dryer systems, as shown. Although energy savings potential is
dependent on a variety of factors (such as type of product dried,
local climate, etc.), The applicant has determined through field
testing that a fuel use savings of between 30 and 60 percent is
possible for most drying applications.
FIG. 7 is a flowchart of a heat exchanger system process 700
according to a preferred embodiment of the present invention.
Process 700 preferably begins with determining 710 the requirements
of the customer. Such requirements typically include moist, heated
exhaust air 105 flow rates, fresh air 116 flow rates, desired
temperature of drying air 103, and information about the crop or
material to be dried. For example, prunes must be dried slowly in
relatively humid air to prevent premature drying of the exterior
surface, which may form a barrier to drying the interior of the
fruit. In contrast, raisins may be dried more rapidly because they
do not exhibit the dry-surface-barrier effect of prunes.
Accordingly, an array size for drying prunes would typically be
smaller than an array for drying raisins, given identical dryers
104. Physical size limits on the retriever 102 may also be imposed
by customer requirements related to facility limitations. For
example, the retriever 102 may be required to fit within
pre-existing spaces or ductwork in the dryer 104. Upon reading the
teachings of this specification, those with ordinary skill in the
art will now understand that, under appropriate circumstances,
considering such issues as dryer operational parameters, matter to
be dried, convenience, economics, user preference, etc., other
customer requirements, such as noise abatement, portability,
materials compatibility, etc., may influence further steps of
process 700.
Array size requirements are preferably determined 720 from the
customer requirements, as shown (at least herein embodying
determining at least one size requirement for said at least one
array). Upon reading the teachings of this specification, those of
skill in the art of analyzing heat transfer in fluid flows will
understand how to calculate, from the customer's requirements, the
desired array size for the above-disclosed preferred array of square
heat-transfer conduits 112.
Preferably, once the array size requirements are determined 720, top
and bottom support plates 124a and 124b, adapted to the determined
720 array size, may be perforated 730 with a pattern of square holes
113 in staggered rows with preferably each square hole 113 oriented
to have a corner facing the general direction of fresh air 116 flow
through the retriever 102, as shown (at least herein embodying
perforating at least one plate with at least one pattern of a
plurality of square perforations in staggered rows, each square
perforation oriented cornerwise to the general direction of flow of
the fresh air over the plate, responsive to said at least one size
requirement). The holes 113 may be made by any conventional means,
such as stamping, machine cutting, laser cutting, or other method
that may minimize cost at the time of manufacture. The array of
holes 113 is preferably centered on the support plates 124a and
124b, and the patterns of holes 113 on each plate 124a and 124b are
preferably substantially identical. Upon reading the teachings of
this specification, those with ordinary skill in the art will now
understand that, under appropriate circumstances, considering such
issues as customer requirements, materials availability,
convenience, economics, user preference, etc., minor variations in
shape, size, and arrangement of holes 113, adaptive to customer
requirements, may suffice.
Preferably, heat-transfer conduits 112 are attached 740 to plates
124a and 124b to form a retriever 102 by extending each end of each
heat-transfer conduit 112 through an aligned pair of holes 113 (one
hole 113 on base plate 124a and one hole 113 on top plate 124b) and
end-flaring the heat-transfer conduits 112 to secure them to the
base plate 124a and the top plate 124b, as shown in FIG. 5B (at
least herein embodying attaching said plurality of heat transfer
conduits to said at least one plate, wherein each said heat transfer
conduit of said plurality of heat transfer conduits is aligned and
oriented to one perforation of said plurality of perforations; and
at least herein embodying pre-configuring, responsive to customer
requirements, at least one retriever comprising at least one array
of at least one plurality of substantially mutually parallel,
substantially vertical heat-transfer conduits having square
cross-sections arrayed in alternating staggered rows relative to a
perpendicular to the general direction of the flow of the stream of
fresh air into the dryer, wherein each heat-transfer conduit is
oriented to have one corner facing in the general direction of the
flow of the stream of fresh air through said retreiver). In an
alternate embodiment, only base support plate 124a is attached 740
to heat-transfer conduits 112 during manufacture, with the function
of top support plate 124b being provided by some portion of a dryer
104 or 604. In another alternate embodiment, neither support plate
124a nor 124b is attached 740 during manufacture, with the functions
of both being provided by some portion of a dryer 104 or 604. Upon
reading the teachings of this specification, those with ordinary
skill in the art will now understand that, under appropriate
circumstances, considering such issues as, materials availability,
fastener technology, convenience, economics, user preference, etc.,
other methods of attaching 740 heat-transfer conduits 112 to plate
124a and 124b, such as welding, gluing, fusing, bolting, screwing,
etc., may suffice.
Once heat-transfer conduits 112 are attached 740 between perforated
support plates 124a and 124b, structures 120 are preferably attached
750 at least between the support plates 124a and 124b to maintain
structural integrity of the retriever 102 (at least herein embodying
attaching structural elements to at least said at least one plate,
wherein said structural elements are structured and arranged to at
least maintain structural integrity of said retriever). Structures
120 are preferably made of steel. Sidewalls 119 preferably serve as
additional structural support to the retriever 102 as well as side
constraints for the flow of fresh air 116 through the retriever 102.
Sidewalls 119 are preferably made of a rigid material, more
preferably a lightweight rigid material, and most preferably
fiberglass. In an alternate embodiment, sidewalls 119 are made of a
flexible, wind-resistant fabric, preferably canvas, and attach to
structures 120.
Additional structure 120 is preferably used to position and support
retriever 102 in the flow of fresh air 116. For example, structure
120 may be used to elevate retriever 102 to engage the flow of fresh
air 116 into dryer 104 as shown in FIG. 4. Preferably, additional
structure 118 assists in directing moist, heated exhaust air 105
into the retriever 102. Structure 118 is preferably made of a rigid
material, more preferably a lightweight rigid material, and most
preferably fiberglass. Preferably, structure 126 supports the bottom
edge of retriever 102. Structure 126 is preferably made of steel.
The methods of attachment 750 are preferably adapted to the various
materials of structures 118, 119, 120, and 126. Preferably the steel
is welded, more preferably bolted. Preferably the fiberglass is
attached to steel with bolts, less preferably with screws, still
less preferably with glue. Upon reading the teachings of this
specification, those with ordinary skill in the art will now
understand that, under appropriate circumstances, considering such
issues as, materials availability, fastener technology, convenience,
economics, user preference, etc., other methods of attaching 750
structures 118, 119, 120, and 126 to each other, such as riveting,
clamping, pressing, etc., may suffice.
Once the retriever 102 has the necessary structure 118, 119, 120,
and 126 attached 750, the retriever 102 is preferably installed 760
in relation to a dryer 104, as shown (at least herein embodying
installing said retriever in at least one dryer). Installation 760
is preferably near enough to dryer 104 to connect by structure 118,
119, and 120,which preferably includes ductwork, more preferably
directly adjacent to dryer 104, and most preferably within dryer
104. In some alternate embodiments, the retriever 102 is built-in to
a dryer 104 during manufacture of the dryer 104, wherein some or all
structure 118, 119, 120, and 126 is preferably common to the
retriever 102 and the dryer 104. For example, the retriever 102
shown in FIG. 2 could have been built in at the time the dryer 104
was constructed. Upon reading the teachings of this specification,
those with ordinary skill in the art will now understand that, under
appropriate circumstances, considering such issues as, dryer
configuration, facility configuration, convenience, economics, user
preference, etc., other relationships of the retriever 102 to dryer
104, such as over, under, beside, integral with the burner 106,
integral with a fresh air 116 inlet vent, vehicle-mounted
transportable with at least partially flexible ductwork, integral
with an exhaust air 114 fan (not shown), etc., may suffice.
Although applicant has described applicant's preferred embodiments
of this invention, it will be understood that the broadest scope of
this invention includes such modifications as diverse shapes and
sizes and materials. Further, many other advantages of applicant's
invention will be apparent to those skilled in the art from the
above-disclosed matters.
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