Note: Descriptions are shown in the official language in which they were submitted.
1
Tube Joining
BACKGROUND OF THE INVENTION
Major problems exist in heat exchangers and air conditioning systems. Heat
transfer
tubes with added fins have many connections. Connecting fins to the tubes is
one problem.
Connecting ends of tubes to header tanks is a more serious problem. When
breaks in
connections occur, leaks develop that exhaust internal fluid and kill the heat
exchangers used
in air conditioning, heat, power and refrigeration systems, for example.
Vibrations and
bimetallic cell corrosion cause breaks in the connections.
Ends of heat exchanger tubes are connected to openings in header tanks at the
ends of
the tubes. Connecting the tubes to the header tanks with friction welding is
not a solution
because the relatively thin tube ends deform. The friction temperatures needed
to fuse and
weld the tube ends and the headers distort and destroy the tube ends and
ports/channels.
Needs exist for solutions to the heat exchange leakage problems and to
problems of
tube-to-header joining in heat exchangers.
SUMMARY OF THE INVENTION
The present invention solves the problems of leakage destruction in heat
exchangers
used in heat, power, air conditioning and refrigeration systems, for example.
The present invention provides tubes with relatively thin central sections to
promote
heat exchange and with large, thicker end sections for joining to the headers.
The large ends
of the tubes are machined flat. Material is removed from the flat ends to
leave projections
having material surrounding the channels on the tubes.
Openings are made in the headers to receive the shapes of the material
surrounding the
channels in the tubes. In one embodiment the large tube ends fit together in
the header face
plates. The tube ends themselves are joined together and are joined with the
header face plates
by friction welding or by brazing. The projections of the tube ends are
friction welded or
brazed in the openings in the header plate. When the tube ends are joined
together by brazing,
the projections of the tube ends extend into the header chamber from the side
of the header face
Date Recue/Date Received 2022-03-16
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plate. The brazing extends from sides of the tube ends, between the flat
surfaces of the tube
ends and the header face plates and along the projections that extend through
the openings in
the header face plates.
When the tube ends and projections are welded to the header face plates, the
tube ends
are flush with and are welded to the header plate openings on the header side
of the face plate.
The tube ends and edges of the large flat tube ends are friction welded to the
header face plates.
The intersecting edges of the header face plates and the header body are
friction welded
together.
Important features of the new invention are and include:
= large ends on heat exchange tubes,
= angular or circular patterns at tube material thickness transition
points, when going from
thick to thin portions of the tube and vice versa,
= joining the large ends to heat exchanger face plates and/or,
= joining large ends of the heat exchanger tubes to each other,
= flattening end surfaces of the enlarged ends of heat exchanger tubes,
= removing material from the flattened ends of the heat exchanger tubes to
form
projections surrounding the inner channels within the tubes,
= inserting the projections into openings in heat exchanger header
connector face plates,
= joining the projections and the flat surfaces of the heat exchanger tubes
to the heat
exchanger header face plates,
= friction welding edges of the projections and edges of the large ends to
corresponding
edges of the heat exchanger header face plates,
= when brazing, extending the projections through and beyond the face plate
and brazing
the surfaces of the projections and of the flat large ends of the tubes to the
heat exchanger
face plates,
= joining all enlarged ends together in a fixed pattern,
= wherein the fixed pattern is circular.
The invention provides tubes having one or more channels and having long, thin
central
heat exchange portions and shorter terminal header portions. The terminal
header portions are
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thicker than the thin central heat exchange portions. Having angular or
circular patterns at tube
material thickness transition points. End faces of the terminal portions are
machined or oblated
to provide outward projections extending around and protecting the one or more
channels. The
outward projections extend from smooth, flat end faces on the thick terminal
header portions.
End plates have inner openings for receiving the outward projections. The end
plates
have inner faces lying against, attached and sealed on the end faces of the
terminal header
portions. The inner openings of the end plates are attached and sealed to the
outward
projections of the end surfaces of the terminal portions.
The end plates and the outward projections are co-extensive from the end faces
of the
tubes in one embodiment. The end plates are welded to the end faces and to the
outward
projections on the end faces of the terminal header portions.
In another embodiment the outward projections extend beyond the face plates
and the
face plates are brazed to the outward projections. Extension of the
projections beyond the face
plates prevents migration of the brazing material into the tube channels.
The tubes are extruded, and opposite surfaces of the middle portions of the
tube are
machined or ablated to remove sections of the tube material and to leave
spaced fins integrally
formed on the thinned middle portion. The fins are slanted with respect to
longitudinal
directions of the middle portions of the tubes, and the one or more channels
are one or more
microchannels.
Plural similar extruded tubes have channels within the tubes. Material is
removed from
the middle portions of the tubes, and spaced fins are left on the thin middle
portions. Thick
terminal header portions are left on ends of the plural tubes having angular
or circular patterns
at tube material thickness transition points. The plural tubes are aligned
horizontally or
vertically or are curved, twisted and sloped with the twisted and tilted tubes
in parallel helical
relationship. The terminal header portions of the plural tubes are aligned and
joined together
by welding before machining or ablating ends of the plural joined terminal
header portions to
create plural end faces and plural outward projections on the plural end
faces. The plural
outward projections extend around and protect the channels. The plural outward
projections
are joined to either flat end plates or inner and outer perimeter rings. The
end plates have
Date Recue/Date Received 2022-03-16
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plural inner openings receiving the plural outward projections on the plural
end faces of the
joined terminal header portions. The plural inner openings of the end plates
are welded or
otherwise joined to the plural outward projections. The end plates are welded
or otherwise
joined to the plural end faces.
The new method includes extruding wide and thick tubes with channels in the
tubes,
and then machining or oblating central portions of the tubes, removing
material in spaced
sections from the central portions, thinning the central portions, forming
fins across the tubes
and leaving thicker terminal header portions at ends of the tubes, having
angular or circular
patterns at tube material thickness transition points, arranging the tubes
parallel to each other,
and welding or otherwise joining the terminal portions of adjacent tubes.
Machining or oblating ends of the joined terminal header portions forms end
faces with
outward projections extending around and protecting the channels.
Providing end plates with openings for receiving the outward projections, and
welding
or otherwise joining the end plates to the end faces and to the projections
readies the end plates
to be joined to header tanks at the ends of the tubes, or providing inner and
outer perimeter rings
and welding or otherwise joining the inner and outer perimeter rings readies
the rings to be
joined to header tanks at the end of the tubes.
Extending the outward projections through and even with a thickness of the end
plates
readies the end plates for welding to the end faces and the projections by
friction stir welding
or hybrid friction diffusion welding.
Extending the outward projections through and beyond the end plates readies
the end
plates and the projections for brazing. The end plates may be brazed or welded
to the end
faces.
Joining thin heat exchanger tubes to manifold header tanks is improved first
by
extruding thick tubes having channels or microchannels. Tube material is
removed from
spaced areas of central portions, leaving fins on thinner heat exchanger
central portions and
thicker terminal header portions. The finned central portions of the tubes are
curved, sloped,
tilted and twisted. The tubes are aligned horizontally, vertically or
angularly, and the terminal
header portions are welded together. Tube material may be removed from the
ends of the
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header portions to form end faces with projections extending from the end
faces and
surrounding the channels or microchannels. End plates with openings to receive
the
projections are attached and sealed to the projections and end faces by
welding or brazing. The
face plates are attached and sealed to openings in the header tanks by welding
or brazing,
solving the problem of thin heat exchanger tubes joined to manifold header
tanks.
Tubes have one or more channels extending through the tubes and have an
elongated
central portions and shorter header portions. The header portions are thicker
than the central
portions. In one embodiment, end faces of the header portions have outward
projections
extending around the one or more channels. The outward projections extend
outward from the
end faces of the thick terminal header portions. The one or more channels are
one or more
microchannels.
End plates have inner openings receiving the outward projections. The end
plates have
inner faces lying against and attached to the end faces of the header
portions. The inner
openings of the end plates are attached to the outward projections of the end
surfaces of the
terminal portions.
In some embodiments the end plates and the outward projections are co-
extensive from
the end faces of the tube, and the end plates are welded to the end faces and
to the outward
projections on the end faces of the header portions. In other embodiments the
outward
projections extend beyond the face plates and the face plates are brazed to
the outward
projections.
The tubes are extruded, and opposite parallel surfaces of the middle portions
of the tubes
are machined, removing material of the tube and leaving spaced fins integrally
formed on the
middle portions. In some embodiments the fins are slanted with respect to a
longitudinal
direction of the middle portion of the tube.
Plural similar extruded tubes have channels in the tubes and have material
removed
from the middle portions and spaced fins left on middle portions of plural
similar tubes and
thick header portions left on ends of the plural tubes. The header portions of
the tubes are
aligned and welded or otherwise joined together before machining ends of the
plural joined
header portions of the tubes and creating plural end faces and plural outward
projections on the
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plural end faces. The plural outward projections extend around the channels in
the tubes. End
plates have plural inner openings receiving the plural outward projections on
the end faces of
the joined header portions. The plural inner openings of the end plates are
welded, brazed or
otherwise joined to the plural outward projections, and the end plates are
welded or otherwise
joined to the plural end faces.
The plural tubes are aligned horizontally, vertically, or are aligned in
curved, sloped,
twisted and tilted parallel helical relationship.
The tubes are curved, at least partially twisted and sloped and at least
partially wound
and twisted and are adapted for form at least part of a helical structure in
an overall cylindrical
structure having a cylindrical shape. The fins are curved, at least partially
twisted and sloped
and at least partially wound and twisted and are adapted for form at least
part of a helical
structure in an overall cylindrical structure having a cylindrical shape.
In some embodiments the tubes have curved middle sections and end sections,
and the
fins on at least one side of the tube are formed slightly concave with center
parts of the fins
offset inward from outer parts of the fins. The fins on one other side of the
tube are slightly
convex with center sections of the fins offset outward from outer sections of
the fins.
The invention provides a method of extruding wide, thick tubes with channels
in the
tubes, machining central portions of the tubes, thereby removing material in
spaced sections
from the central portions, forming fins across the tubes. The method provides
thinner central
portions of fins, leaving header portions at ends of the tubes and having
angular or circular
patterns at tube material thickness transition points. The tubes are arranged
parallel to each
other and are joined at the thicker portions of adjacent tubes. Machining ends
of the joined
terminal header portions forms end faces. Some end faces have outward
projections extending
around the channels. Some end plates have openings for receiving the outward
projections.
The end plates are then joined to the end faces and some embodiments to the
projections.
Extending the outward projections through and even with a thickness of the end
plates,
the joining of the end plates with the end faces and the projections, if any,
is by friction stir
welding or hybrid friction diffusion welding.
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The outward projections extend through and beyond the end plates when the
joining of
the end plates to the projections is by brazing. The joining of the end plates
to the end faces is
by welding.
In one form, the method of the invention curves the tubes longitudinally after
forming
the thinner central portions with fins, curves the thinner curved tubular
central portions and
curves the thicker curved tubular end portions. The projections from the end
faces are curved,
and curved openings in the end plates receive the curved projections. The end
plates are
welded to the end faces and welding or brazing joins the end plates to the
projections.
In another form, the method of the invention curves the tubes longitudinally
after
forming the thinner central portions with fins, curved the thinner curved
tubular central portions
and curves the thicker curved tubular end portions. The projections from the
end faces are
curved and curved inner and outer perimeter rings receive the curved
projections. The inner
and outer perimeter rings are welded to the end faces and welding or brazing
joins the inner and
outer perimeter rings to the projections.
These and further and other objects and features of the invention are apparent
in the
disclosure, which includes the above and ongoing written specification, with
the claims and the
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 shows a tube extrusion with micro channels.
Figure 2 shows making perpendicular fins by cutting away material.
Figure 3A shows making angular fins by cutting away material and thereby
forming a
monoblock finned tube with square pattern at tube material thickness
transition points.
Figure 3B shows making angular fins by cutting away material and thereby
forming a
monoblock finned tube with angled pattern at tube material thickness
transition points.
Figure 3C shows making angular fins by cutting away material and thereby
forming a
monoblock finned tube with circular pattern at tube material thickness
transition points.
Figure 4 shows an extrusion of a tube having a single port.
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Figure 5 shows the extrusion of the tube shown in Figure 4 after cutting away
material
and forming perpendicular fins.
Figure 6 shows the extrusion after cutting away material to form angular fins.
Figure 7 shows arranging tubes horizontally between flat vertical header
connector
plates.
Figure 8 shows arranging tubes vertically between flat horizontal header
connector
plates.
Figure 9 shows arranging the tubes cylindrically between flat annular header
plates.
Figure 10 shows cylindrically arranged curved tubes.
Figure 11 shows curved, twisted, tilted, helically arranged tubes with sloped
ends.
Figure 12 shows joining adjacent tube ends by friction stir welding or hybrid
friction
diffusion bonding.
Figure 13 shows machining projections on tube ends.
Figure 14 shows a flat header connector plate with openings for receiving tube
end
projections.
Figure 15 shows joined tube ends with projections.
Figure 16 shows tube ends with projections frictionally welded in the plate.
Figures 17A and 17B show flattening ends at angles with respect to the tube
slope.
Figure 18 shows joining flattened angular ends.
Figures 19A and 19B show machining joined flat ends to form projections.
Figures 20A and 20B show a flat ring plate with openings for receiving the
projections.
Figures 21A and 21B show joining end projections within the flat ring plates
by friction
welding.
Figure 22 shows a tube with a large end.
Figure 23 shows machining a projection on a tube end for brazing.
Figure 24 shows a flat header connector plate for receiving machined ends with
the
projections.
Figure 25 shows tubes with the large ends and projections ready to be mounted
on and
in the header connector plate.
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Figure 26 shows brazing and end in the plate after insertion of the
projections through
the plate.
Figure 27 shows a brazed assembly to compare to fusion welding.
Figure 28 shows fusion welding compared with brazing in Figures 26 and 27.
Figure 29A shows the flattening steps of Figures 17A, 17B and 18.
Figure 29B shows an embodiment in the form of the curved, sloped, tilted and
twisted
tubes in a helical cylindrical arrangement of many tubes without machining.
Figure 30 shows inner and outer machined perimeter sections of the tube ends
already
welded.
Figure 31 shows a helical coil assembly with machined upper and bottom
perimeters for
connecting corresponding rings.
Figure 32 shows the end rings attached to the header portions and welded
areas.
Figures 33A and 33B show upper and bottom solid state coil polished flat
surfaces for
further attachment to header tanks or vessels.
Figures 34 to 38 show Story Telling Charts illustrating the forming and
joining of tube
ends in accordance with the present invention.
DETAILED DESCRIPTION
Figure 1 shows a tube extrusion with micro channels. The solid extrusion 10
has
multiple through ports or channels 11 and sloping sides 13 with side
connecting walls 15.
Figure 2 shows making perpendicular films by cutting away material. Material
portions 17 have been removed to leave perpendicular fins 19. The resulting
tubes 20 have
relatively smaller middle portions 21 and larger ends 23.
Figure 3A shows making angular fins by cutting away material and thereby
forming a
monoblock finned tube with square pattern at tube material thickness
transition points.
Figure 3B shows making angular fins by cutting away material and thereby
forming a
monoblock finned tube with angled pattern at tube material thickness
transition points.
Figure 3C shows making angular fins by cutting away material and thereby
forming a
monoblock finned tube with circular pattern at tube material thickness
transition points.
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Figure 4 shows an extrusion of a tube having a single port. A solid extrusion
block 40
cut from a continuous extrusion has a single central port or channel 41,
sloping side walls 43
and laterally extending side connection walls 45.
Figure 5 shows the extrusion of the tube shown in Figure 4 after cutting away
material
and forming perpendicular fins. Portions 47 extending across the extrusion
have been removed
to leave perpendicular fins 49 extending across the resulting tube 50. Tube 50
has large ends
33 around a smaller middle 51.
Figure 6 shows the extension after cutting away material to form angular fins.
Material
has been removed from portions 67 of a solid extrusion 40 to leave fins 69 at
an angle to
dimensions of the resulting tube 70.
Figure 7 shows arranging tubes horizontally with the flat vertical header
plates. Tubes
50 have large ends 53 connected to vertical mounting plates 80 which in turn
are connected to
header tanks, vessels, shells and lids to create header chambers (not shown).
Figure 8 shows arranging tubes vertically with flat horizontal header plates.
Vertically
arranged tubes 50 have large ends 53 connected to horizontal mounting plates
82 which are
connected to header chambers.
Figure 9 shows arranging tubes in a circle with flat circular header plates.
Vertically
arranged tubes 50 have large ends 53 connected to upper and lower annular
mounting plates 84
which are connected to header chambers.
Figure 10 shows curved tubes circularly arranged tubes. Vertically arranged
curved
tubes 90 have thinner curved tubular central sections 91 and thicker curved
end sections 93.
The curved openings 97 appear in the upper and lower annular mounting plates
95.
Figure 11 shows curved, twisted, tilted, helically arranged tubes with sloped
ends.
Twisted, tilted helical tubes 100 have larger ends 103 of similar shapes.
Smaller middle
portions 101 of tubes 100 have the continued curved, twisted, tilted and
helical shape of the
remainder of the tubes 100. The outer header rings 105 are flat for connection
to header
vessels.
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Figure 12 shows joining adjacent tube ends by friction stir welding or hybrid
friction
diffusion bonding. Large ends 53 of tubes 50 are joined 110 together by
friction stir welding
(FWS) or hybrid friction diffusing bonding (HFDB) 112.
Figure 13 shows machining projections on tube ends. Material 121 is removed
from
ends 125 of large ends 53 of tubes 50 which have been joined 110 to leave
projections 127.
Figure 14 shows a flat plate with openings for tube end projections.
Figure 15 shows joined tube ends with projections.
Flat plates 130 have openings 137 to receive and hold the projections 127 from
the ends
125.
Figure 16 shows tube ends with projections frictionally welded in the plate.
Ends 129
of the projections are friction welded 139 to edges of the openings 137 in the
flat plates. The
welding is done on the chamber-facing side 131 of the flat plates.
Figure 17A shows a single curved, twisted, tilted and helically shaped tube.
Tubes 100
are aligned and parts of ends 103 are removed so that the ends 107 are angular
to the tubes and
are aligned parallel in the opposite end plates.
In Figure 17B each curved, twisted, tilted and helical formed tube 100 has
enlarged ends
103 and fins 101. Enlarged ends are to be cut or machined in order to flatten
them horizontally.
Figure 18 shows joining flattened angular ends. Aligned angular end faces 109
of wide
end parts 103 of tubes 101 are friction welded 140 so that complete cylinders
of welded tube
ends 103 are joined together.
Figures 19A and 19B show machining joined flat ends. Parts of material 141
from
welded together ends are removed to provide projections 145 as shown in the
two figures. The
angular removal of parts of the ends and the projections surrounding the
openings of the
channels in the tubes provide large communication openings 146 that reduce
refrigerant
pressure drop.
Figures 20A and 20B show a ring with openings for receiving the projections.
Flat ring
150 has openings 155 to receive the projections 145.
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Figures 21A and 21B show joining end projections within the rings by friction
welding.
The inside edges 157 of the openings 155 and the end edges 147 of the
projections 145 are
friction welded 159 on the vessel side 151 of connecting flat ring 150.
Figures 22-27 show joining of tubes and header connector plates by brazing
compared
with fusion welding in Figure 28.
Figure 22 shows a tube with an enlarged end. Tube 200 is formed with large
ends 203
and a relatively thin 201 central section. Fins may be formed in the central
section by removing
material from the extruded tube.
Figure 23 shows machining a projection on a tube end for brazing. Sections 204
are
removed from the ends to leave a projection 205 extending from surfaces 207.
Figure 24 shows a flat plate for receiving machined ends.
Figure 25 shows brazing tubes on and in the plate.
The header connector plate 210 has openings 215 to receive the projections 205
at the
large ends 203 of tubes 200.
Figure 26 shows brazing and end in the ring after insertion of the projections
in the ring.
the projections 205 extend beyond the header vessel side 211 of the header
connector plate.
Brazing is continuous between surfaces 207, projections 205, complementary
outer surfaces
217 and surfaces of openings 215.
Figure 27 shows a brazed assembly to compare to fusion welding.
Figure 28 shows fusion welding to compare with brazing.
The protrusion 209 of the projection 205 as shown in Figures 26 and 27 is
necessary to
prevent the filler material from travelling and entering the micro ports of
the tubes.
Friction stir welding (FSW) or hybrid friction diffusion bonding (HFDB) does
not
require the extension of the projections 225 beyond the vessel side 231 of the
header connecting
plate 230.
In one embodiment of the invention the tubes are made without protrusions in
end faces.
The step of machining of end faces to produce protrusions by removing material
from the end
faces is avoided.
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Figure 29A shows the flattening steps of Figures 17A, 17B and 18. Tubes 100
are
aligned and parts of ends 103 are removed so that the ends 107 are angular to
the tubes and are
aligned parallel in the opposite end plates. Each twisted, tilted and helical
curved tube 100 has
enlarged ends 103 and fins 101. Aligned angular end faces 109 of wide end
parts 103 of tubes
101 are friction welded 140 so that complete cylinders of welded tube ends 103
are joined
together.
Figure 29B shows such an embodiment in the form of curved, sloped, tilted and
twisted
tubes 300 in a helical tube cylindrical arrangement 350, as shown in Figures
11, 17A, 17B and
21B. Header portions 333 are shown without the machining and flattening.
Figure 30 shows machined inner perimeter 442 and machined outer perimeter 444.
Welding areas 440 are shown between the machined perimeter areas 442 and 444
of the
flattened headers 446.
Figure 31 shows a helical coil arrangement 600 of curved, twisted, tilted and
sloped
tubes 400 with machined inner perimeters 450 and 451, machined outer
perimeters 452 and 454
together with their corresponding upper connecting end rings 462 and 462 and
the bottom
connecting end rings 474 and 476.
Figure 32 shows the end rings 462, 464, 474 and 476 attached respectably to
the header
portions 480 and 481, the upper welding areas 482 between adjacent upper tube
headers 480
and the upper perimeter welding areas 484 and 486 between the upper end rings
462 and 464
to the upper tube headers 480. The outer areas 478 are shown extended outward
from the lower
joined headers 481.
Figure 33A and 33B show a welded solid state helix coil assembly 700 with re-
machined
and/or polished upper and bottom surfaces 500 and 502 respectably to further
be connected to
coil header tanks or vessels.
Story Telling Charts, enclosed as Figures 34 to 38, describe by illustration
and labels
the forming and joining of tube ends by steps of clamping and flattening
headers, welding
adjacent headers in areas spaced from channels, machining header faces, use of
header end
plates and polishing ends of said solid state robust structures in accordance
with the present
invention.
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While the invention has been described with reference to specific embodiments,
modifications and variations of the invention may be constructed without
departing from the
scope of the invention, which is defined in the following claims.
Date Recue/Date Received 2022-03-16
