Note: Descriptions are shown in the official language in which they were submitted.
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SYSTEM AND METHOD FOR GEOTHERMAL CONDUIT
LOOP IN-GROUND INSTALLATION AND SOIL
PENETRATING HEAD THEREFOR
TECHNICAL FIELD
A geothermal, in-ground, conduit system and a
method of constructing and installing same, to capture
thermal energy stored in soil, are described.
BACKGROUND ART
With the high cost of electricity and gas, more and
more interest is directed to the use of other sources of
energy and in recent years particular attention has been
given to tapping the geothermal energy stored in the ground.
Such energy is renewable as it comes from the sun, but more
important such energy does not produce any harmful gas
emission which is released in the atmosphere as is the case
with combustible products. The
use of such energy also
results in a cost-saving to heat and cool a building
structure. It has been calculated that by using geothermal
energy, as opposed to combustible energy, an average house
prevents the emission of 2.5 to 5 tons of carbon dioxide into
the atmosphere, each year. Accordingly, there is a need to
improve the technology to extract this geothermal energy and
to develop new methods to tap this energy for existing
building structures as well as new building structures.
Nearly half of the thermal energy which comes from
the sun is stored in the earth and water on the planet. At a
depth of approximately 2 meters, the temperature of the earth
is constant during winter months, as well as summer months,
and depending on the geographical location of the building it
varies between 5 to 12 C.
This is the energy that a
geothermal system taps into. Also, a geothermal system
produces heat which is more uniform than an electrical or gas
heating system. The
most popular geothermal system is a
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close-circuit vertical system wherein tubes are disposed in
bore holes or tubes driven into the soil and in which a
conduit loop is disposed. The spacing of the tubes that form
the conduit loop are very close to one another and usually
spaced about 3 inches apart. The
tube is then filled with
Bentanitejm cement.
Because the conduits are closely spaced
and located within a hole bored in rock or in tubes, the heat
exchange with the surrounding soil is poor and consequently
it is often necessary to have to bore many holes and install
many pipes to extract sufficient amount of heat from the
ground.
Accordingly, these systems have been found to be
expensive.
Usually, for an average household of about 1200
square feet, there is required approximately 750 linear feet
of in-ground tubing interconnected in series and into a
thermo pump. The
thermo pump circulates a heat exchange
liquid in the closed loop circuit disposed in the ground and
the liquid is used to extract and convect the heat from the
soil to the thermo pump which compresses the liquid to
extract heat therefrom. During hot summer months, the thermo
pump operates in reverse and the geothermal circuit is used
to cool the liquid convected through the closed circuit with
the liquid extracting heat from inside the building by the
thermo pump. It is pointed out that these tubes can extend
from 100 to 400 feet into the ground. Often it is necessary,
at those depths, to drill through the bedrock and this adds
considerably to the cost of the installation of the system.
A vertical installation is preferred over a horizontal
installation due to the fact that in a horizontal
installation it is necessary to have a very large terrain and
usually the tubing is installed in the ground in the form of
continuous overlapped loops. A
big advantage of using a
geothermal energy heating/cooling system is that the cost of
the installation can be recovered within a period of 5 to 10
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years and thereafter comes the economy wherein the heating
and air-conditioning costs are greatly reduced.
SUMMARY OF INVENTION
It is a feature of the present invention to provide
a geothermal in-ground conduit system and method of
installation which greatly reduces the disadvantage of the
prior art mentioned hereinabove.
Another feature of the present invention is to
provide a soil penetrating head for use in a geothermal in-
ground conduit system to position a flexible tubing loop in
the soil and which greatly facilitates the installation of
the loop into the soil.
Another feature of the present invention is to
provide a geothermal in-ground conduit system comprised of a
loop of flexible tubing and a soil penetrating head secured
at a lower end of the loop and wherein the head is driven
into the soil by a static or dynamic force transmitting shaft
which is retractable or which may be utilized as a foundation
support pile or a conduit for convecting a heat exchange
liquid therein and wherein the soil penetrating head remains
imbedded in the soil with the loop of flexible tubing.
Another feature of the present invention is to
provide a geothermal in-ground conduit system comprised of a
loop of tubing material which is connectable to a soil
penetrating head to position the loop of tubing material at a
predetermined depth into the soil and wherein the soil
penetrating head is retractable after the loop of tubing
material has been positioned.
Another feature of the present invention is to
provide a geothermal in-ground conduit system which can be
installed under the footings of new building structures and
to make it accessible to the proprietors of such building
structures for future use.
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Another feature of the present invention is to
provide a geothermal in-ground conduit system which can be
installed into the ground from inside a foundation of an
existing building and which can be placed into the soil
surrounding the building at a multitude of desired angles.
Another feature of the present invention is to
provide a geothermal in-ground conduit system which does not
require drilling through the bedrock.
Another feature of the present invention is to
provide a geothermal in-ground conduit system comprised of at
least one loop of flexible tubing and wherein the elongated
side sections of the loop are spaced-apart a distance
sufficient to permit extraction of heat from its surrounding
areas without interfering from the surrounding area of the
adjacent elongated side sections and wherein there are no
tubes required for housing the loop as the side sections are
each in direct contact with the surrounding soil thereby
greatly increasing the efficiency of such closed loop conduit
systems.
According to the above features, from a broad
aspect, the present invention provides a geothermal in-ground
conduit system comprising at least one loop of flexible
tubing material adapted to convect a heat exchange liquid
therein. The
loop has a lower end section and opposed
spaced-apart elongated side sections communicating with the
lower end section to form the loop. The lower end section is
adapted to be driven in the soil for permanent burial therein
with at least a major portion of the side sections and in
direct contact with the soil for heat exchange therewith.
According to a further broad aspect, the present
invention provides a geothermal in-ground conduit system
which comprises at least one loop of flexible tubing adapted
to convect a heat exchange liquid therein. The loop has a
lower end section and opposed spaced-apart elongated side
sections communicating with said lower end section to form
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the loop. The lower end section of the loop is secured to a
soil penetrating head. The
soil penetrating head has a
leading soil penetrating face formation.
Coupling means is
provided with the soil penetrating head to receive a force
transmitting shaft to transmit a pushing force against the
soil penetrating head to displace the head in the soil while
pulling the loop and guiding the loop into the soil as the
soil penetrating face formation forms passages in the soil.
According to a further broad aspect of the present
invention there is provided a soil penetrating head for use
in a geothermal in-ground conduit. The soil penetrating head
has a leading soil penetrating face formation.
Coupling
means is secured to the soil penetrating head rearwardly of
the leading soil penetrating face formation and adapted to
receive a force transmitting shaft. The leading soil
penetrating and ramming face formation has a convex shaped
forward sharp edge and opposed symmetrical shaped side walls
tapering outwardly from an apex of the convex forward sharp
edge. It
also has passage means to receive a lower end
section of at least one loop of flexible tubing from a rear
end of the soil penetrating head.
According to a still further broad aspect of the
present invention the soil penetrating head is detachably
secured from the loop of flexible tubing after the loop has
been positioned in the soil at a predetermined depth whereby
the soil penetrating head is retractable with the loop of
flexible tubing remaining buried in the soil.
According to a still further broad aspect of the
present invention there is provided a method of constructing
an in-ground conduit system to capture thermal energy stored
in the ground. The method comprises the steps of securing a
lower end section of at least one loop of flexible tubing to
a soil penetrating head. The loop has opposed spaced-apart
elongated side sections. The
soil penetrating head has a
leading soil penetrating face formation. The soil penetrating
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head is engaged by a lower end of a force transmitting shaft
supported at a desired angle with respect to a soil surface
adjacent a foundation of a building structure. A
pushing
force is applied to the force transmitting shaft to displace
the soil penetrating head in the soil with the opposed
elongated side sections maintained spaced-apart. The
soil
penetrating head pulls the loop and guides it into the soil
as the penetrating face formation forms passages for burial
of at least a major portion of the loop.
BRIEF DESCRIPTION OF DRAWINGS
A preferred embodiment of the present invention
will now be described with reference to the accompanying
drawings in which:
FIG. 1 is a fragmented
schematic view illustrat-
ing the construction of the geothermal in-ground conduit
system of the present invention;
FIG. 2 is a perspective view, partly exploded,
showing the construction of the soil penetrating head and its
connection to a loop of flexible tubing as well as to a force
transmitting shaft;
FIG. 3 is
a side view showing a modification of
the soil penetrating head of Figure 2;
FIG. 4 is
a top, rear view showing a further
modification of the soil penetrating head;
FIG. 5 is
a further rear view showing a still
further modification of the soil penetrating head;
FIG. 6 is
a schematic illustration of a still
further modification of the soil penetrating head;
FIG. 7 is a schematic
illustration showing the
interconnection of loops of flexible tubing and the use of
the force transmitting shaft as a conduit integrated with the
loops of flexible tubing and for convecting the heat exchange
liquid therein;
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FIG. 8 is a fragmented side view illustrating
the construction of spacing elements connectable with the
force transmitting shaft for maintaining the elongated side
sections of the flexible tubing loop in spaced-apart
relationship as it is drawn into the soil;
FIG. 9 is a simplified perspective view of a
pneumatic force applying device utilized to drive the soil
penetrating head and the flexible tubing loop into the soil
from inside a foundation of an existing building;
FIG. 10 is a perspective view illustrating the
construction of a pneumatic force applying device utilized to
drive shaft sections of the force transmitting shaft into the
soil;
FIG. 11 is a top view of the pneumatic force
applying device;
FIG. 12 is a further perspective view of the
pneumatic force applying device illustrating an assembly of
protection plates secured about the clamping jaws of the
device;
FIG. 13 is a fragmented sectional view showing
the in-ground conduit system installed under a footing of a
foundation structure;
FIG. 14 is a simplified section view illustrating
various orientations of the flexible tubing loops that can be
installed from inside an existing foundation structure.
FIG. 15 is a schematic illustration of a heavy
equipment used to apply a dynamic force against the force
transmitting shaft to drive the soil penetrating head and
loop of flexible tubing into the soil;
FIG. 16A is a perspective view of a further
example of the construction of a soil penetrating head which
is adapted to be retracted after the loop of flexible tubing
has been positioned into the soil for burial thereinto;
FIG. 168 is a side view of Figure 16A;
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FIG. 16C is a fragmented side view of the soil
penetrating head showing the curved section of the loop of
flexible tubing material engaged therewith;
FIGs. 17A to 17C are side views of the soil
penetrating head of Figure 16A illustrating how the lower end
section of the loop of tubing is positioned into the soil and
the soil penetrating head retracted therefrom;
FIG. 17D is a side view similar to Figure 17A but
showing a modification of the soil penetrating head wherein a
soil penetrating nose member is detachably connected to the
leading edge of the soil penetrating head;
FIG. 17E is a side view showing a soil penetrating
nose member secured to the lower end section of the loop and
engageable by the leading edge of the soil penetrating head;
FIG. 18 is a simplified perspective view showing
the construction of the loop of flexible tubing material;
FIGs. 19A and 19B are perspective views showing a
further embodiment of a soil penetrating head with a
detachable force transmitting shaft engageable therewith;
FIG. 20 is a perspective view showing the
construction of the force transmitting shaft lower end;
FIG. 21 is a simplified side view showing how the
loop of flexible tubing, as shown in Figure 18, is positioned
within the soil; and
FIG. 22A is a top view of a hole made in a
concrete floor slab of a building structure illustrating a
plurality of loops driven in the soil below the slab in
different directions;
FIG. 22B is a schematic side view illustrating the
position of loops driven into the ground at different angles
and with the property boundaries of a building lot; and
FIGs. 22C and 22D are similar illustrations of
different loop patterns of tubing loops driven in the soil of
a building lot.
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DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings, and more
particularly to Figure 1, there is shown a schematic
illustration of a building structure 10, herein a residential
home, equipped with the geothermal in-ground conduit system
11 of the present invention.
Essentially the system
comprises of at least one, herein a plurality of flexible
tubing loops 12, each loop being connected in series to form
a closed loop conduit circuit which is connected to a thermo
pump 13 adapted to circulate a heat exchange liquid within
the circuit to extract heat from the soil 14 surrounding the
loops for heating the building 10. The
pump 13 is
conveniently installed inside the building structure 10 or an
attached structure 10'. By
reversing the operation of the
pump 13, heat from inside the building can be cooled by heat
exchanging the heat with the heat exchange liquid and
circulating into the earth where the soil surrounding the
loop cools the heat exchange liquid within the tube thereby
extracting heat therefrom. The operation of the thermo pump
is well known in the art.
Each of the loops 12 has a pair of elongated,
spaced-apart, side sections 15 and 15' and a lower end
section 16, hereinshown in phantom line, which is secured to
a soil penetrating head 17. The loop is formed of HDPE (high
density polyethylene). The
loops 12, as well as the soil
penetrating head 17, are embedded within the ground at a
convenient location, herein close to the foundation wall 17
of the building 10, but they could of course be located
further away. The soil penetrating heads 17 of the loops are
driven into the ground by a force transmitting shaft, as will
be described later, to a predetermined depth or until the
soil penetrating head is arrested by the bedrock 18 or
otherwise.
Accordingly, the depth of the bedrock could
determine how many loops are to be placed into the ground to
provide heat for the square footage area of the building
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structure 10 to be heated.
Usually, for a residential
building structure of about 2,000 square feet, there is a
requirement to dispose approximately 750 feet of tubing into
the ground.
However, because, as shown in Figure 1, the
flexible tubing is in direct contact with the surrounding
soil, it is more efficient in absorbing heat or releasing
heat into the ground as opposed to conventional systems and
less tubing may be required as compared with the prior art
methods where the elongated side sections 15 of the loops are
closely spaced and often disposed in a bore hole in a rock
surface or in a metal tube driven into the ground.
With reference now to Figure 2, there will be
described the construction of the soil penetrating head 17.
As hereinshown the head 17 has a leading soil penetrating and
ramming face formation 18 which has a convex-shaped forward
sharp edge 19 and opposed symmetrically shaped bowed side
walls 20 and 20' extending outwardly from an apex of the
convex forward shape edge 19. Coupling means, as hereinshown
in the form of a hollow tube section 21, is secured between
the symmetrically shaped side walls 20 and 20' and is
positioned along a straight central axis 22 which passes
through the apex of the sharp edge 19 and at mid-length of
the opposed symmetrical shaped side walls and mid-length of
the opposed end edges 23 and 23' of the soil penetrating
heads 17. The hollow tube section 21 is dimensioned whereby
to receive therein a lower end section 24 of a force
transmitting shaft 25.
The soil penetrating head 17 is further provided
with a curved passage therein to permit the passage of the
flexible tubing to form a curved lower end section 16, as
hereinshown. Alternatively, as shown in Figure 3, a curved
conduit 27 of high density polyethylene may be secured inside
the soil penetrating head 17 and be provided with extension
portions 27' for connection with a respective one of the
elongated side sections 15 and 15' of the loop by socket
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fusion, butt fusion or electrofusion.
Further, as shown in
Figure 3, the tubular connector 21', as hereinshown, is in
the form of a pipe section having an engageable formation,
herein an inner thread 28 for detachable connection with the
threaded end 29 of the force transmitting shaft 25'.
For the installation of the loops 12 into the
ground surface 14', a trench 30 may be dug out from the top
surface 14' of the ground and in which each loop 12 is driven
into the ground by connecting or placing the free end of a
force transmitting shaft 25 into the coupling tube 21 for
transmitting a directional pushing force against the soil
penetrating head to displace the soil penetrating head 17
into the soil 14. As the head is driven into the soil, the
leading soil penetrating and ramming face formation 18
displaces the soil and obstacles in its path whereby to form
a passage for the loop side sections 15 and 15' as it is
pulled into the soil for permanent burial once the soil
penetrating head reaches a predetermined depth or is arrested
against the bedrock or other hard sub-strata. It is pointed
out that the elongated side sections 15 and 15' of the loop
are spaced-apart about 18 inches from one another and
adjacent loops are positioned about three feet apart. After
each of the loops 12 are installed below the ground surface,
the loops are interconnected to one another by connectors,
such as the connectors 31 shown in Figure 7 and intermediate
pipe sections 32, as shown in Figure 1.
Because the tubes
are formed from high density plastics, it is preferable to
secure the connectors and intermediate tube sections 32 by
heat fusing them together or using a melting adhesive whereby
there are no leaks in the joints. Once
the joints are all
interconnected and the free end sections 33 are brought above
ground level 14, the trench 30 may be refilled with soil.
As shown in Figure 2, the soil penetrating head 17
is preferably formed of steel or any other suitable hard
material such as structural PVC material. The
bowed side
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walls 20 and 20' are also reinforced by transverse rib
formations or braces 35. If
the soil penetrating head is
constructed of a plastic material then a hard metal blade 19'
is rigidly secured in the head 17 during the molding of the
head 17.
As shown in Figure 4, the soil penetrating head 17
may also be provided with transverse guide flanges 36 to add
stability to the head as it penetrates into the soil.
Figure 5 shows a further modification of the soil
penetrating head, herein head 17'. As shown, the head 17 is
in the form of a cross defined by transverse soil penetrating
and ramming face formations 18 and 18' whereby to house a
pair of hollow tube sections 27 and 37 which are superimposed
under the coupling tube 21 whereby two of the loops can be
installed into the ground surface with a single soil
penetrating head 17'.
Figure 6 is a schematic illustration showing a
further design of the soil penetrating head wherein the head
is provided with three elongated flexible tubing sections 40
which are in communication with a hollow coupling tube 21"
through conduits 41.
With such an arrangement, the force
transmitting shaft 25" is a hollow shaft permanently secured
to the head for convecting the heat exchange liquid therein
and into the opposed side sections 40 of the loop. The inner
transverse surface area of the force transmitting shaft 25"
is equal to the totality of the inner transverse surface area
of the three opposed side sections 40 of the loop.
Figure 7 illustrates an arrangement which is
similar, wherein the force transmitting shaft is a hollow
shaft with the two elongated side sections 15 and 15'
interconnected thereto by conduit connection 15", also
illustrated in phantom lines in Figure 2. The heat exchange
liquid is convected into the hollow shaft 25" and out through
the elongated side sections 15 and 15' whereby to feed the
adjacent force transmitting hollow shaft 25"' with the
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circulation liquid flow repeating with the next section and
so on until the liquid convection circuit is complete.
Referring now to Figure 8, there is shown generally
at 10 a spacer element 42 which is securable to the force
transmitting shaft 25. The force transmitting shaft 25 is a
composite shaft consisting of shaft sections 43
interconnected end-to-end by a threaded end section at the
end of one shaft section and a threaded bore 45 at the other
end of each section 43. In order to maintain the elongated
side sections 15 and 15' of the flexible tubing loop in a
spaced-apart arrangement as it descends into the soil, the
spacer element 42 is connected at selected ones of the
connecting joints between the shaft sections 43. As
hereinshown the spacer element 42 has projecting arms 46
which are flat with sharp edges and oriented to cut through
the soil. The arms 46 are axially aligned with one another
and extend transversely of the force transmitting shaft 25
for supporting a guide tube 47 at opposed free ends thereof.
Each of the guide tubes 47 are disposed to receive a
respective one of the spaced-apart side sections 15 and 15'
of the flexible tube therethrough to maintain the side
sections spaced-apart as they are drawn into the soil. The
spacer element 42 has a connecting hub 48 also formed with a
threaded spigot 49 and a threaded bore 50 whereby to be
coupled to the threaded end section 44 and threaded bore 45
of the opposed shaft sections 43.
With reference again to Figure 1, there is shown
another use of the force transmitting shaft 25 after the
loops have been installed into the soil and the soil
penetrating head 17 has reached the bedrock or a solid soil
strata. As
hereinshown, these force transmitting shafts 25
can be used as a pile which is connected to a bracket 55
immovably secured to the foundation wall 17 to support the
foundation should this be desired due to the quality of the
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soil, i.e., clay or other unstable soils on which the
foundation rests.
With reference now to Figures 13 and 1, there is
shown another version of the installation of the in-ground
conduit circuit or system 11. As shown in these Figures, a
series of loops 12', see the right-hand side of Figure 1, are
disposed into the ground surface after the excavation hole
has been made to build the foundation 55.
After the
excavated hole has been surveyed for the footing
implantation, the loops of flexible tubing 11 are installed
into the ground along a straight line calculated to lie under
the foundation footing 56 and offset from the center line 57
of the footing on an interior side 17' of the footing side
wall 17. These loops 12 may be interconnected under the top
surface 58 of the excavated hole 59 with the free ends of the
loop circuit, or of the serially connected loops, extending
above the top surface 58. One of these free end sections are
herein designated by reference numeral 60. These tube open
end sections 60 are disposed in an insulated protective
sleeve 61 about which concrete 62 is to be poured and set to
form the footing 56.
Accordingly, the entire circuit of a
geothermal in-ground conduit system is available to the
building to be erected on the foundation from the two free
end sections 60 of the circuit ready to be connected by
piping to a thermo pump.
Preferably, these two free end
sections 60 are located at a location where the mechanical
room is to be build
With reference now to Figures 9 to 12, there will
be described how the geothermal in-ground conduit system of
the present invention is installed under an existing building
structure.
Figure 9 illustrates an existing building
structure foundation, herein constituted by the foundation
wall 17, the footing 56 and the concrete floor slab 65. It
also shows the joist 66 of an upper floor and these joists 66
form a ceiling 67 which is usually 8 to 9 feet above the
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concrete floor slab 65. Accordingly, there is very limited
space in which to install equipment capable of installing
drive piles to install the flexible tubing loops and their
associated soil penetrating heads into the ground surface
under the foundation. This
is accomplished in this
restricted space by a pneumatic force applying device 70
which is secured to a foundation anchor plate 71 which is
temporarily secured by anchor bolt 72 onto the inner surface
17' of the foundation wall 17 or on the outer surface 65' of
the concrete floor slab 65. The anchor plate 71 is provided
with a pair of parallel connecting flanges 73, each having a
hole 74 for connection to the pneumatic force applying device
70.
As shown in Figures 10, 11 and 12, the pneumatic
force applying device has a pair of pistons 75 each having a
piston cylinder 76 and a piston rod 77. The piston rods have
a piston rod end 78 in the form of a fork adapted to be
engaged with a respective one of the holes 74 of the plate 73
by a lock pin 79. The
piston cylinders 76 are coupled
together in spaced parallel relationship by a force
transmission shaft engaging assembly 80. The
piston
cylinders are connected to a pressurized fluid supply, not
shown.
The shaft engaging assembly 80 is comprised of an
attachment frame 81 immovably secured to the cylinders 76 to
maintain them in spaced-apart parallel relationship. A pair
of clamping jaws 82 is slidingly displaceable on a respective
angulated side plate 81. The slide plates 81 are retained
stationary in spaced-apart facial relationship to support the
clamping jaws 82 in a spaced-apart relationship to define a
shaft passage 83 therebetween and extending parallel to the
cylinders. The clamping jaws 82, when at a lower end of the
slide plates, as hereinshown, are spaced further away from
one another to define a non-engaging position with the shaft
section 43 of the composite force transmitting shaft as
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previously described. The clamping jaws 82, when moving to
an upper end of the slide plates by downward displacement of
the cylinders 76 by the application of fluid pressure,
converge towards one another and clamp the shaft section 43
in the shaft passage 83 to impart a downward pushing force on
the shaft section to drive the soil penetrating head and the
flexible tubing loop into the ground surface. Of course, as
shown in Figure 9, a hole 90 of sufficient size is first made
into the concrete floor slab at an appropriate location where
the flexible tubing assembly is to be installed.
With further reference to Figures 10 to 12, the
attachment frame 81 is further comprised of a first bridge
plate 84 which extends between the cylinders. An aperture 85
is provided in the first bridge plate intermediate the
cylinder 76 and dimensioned for receiving the shaft section
43 in close sliding fit therein. A further bridge plate 86
is secured at the top end of the cylinders 76 and extends
between the cylinders above the first bridge plate and is
provided with a guide edge formation 87 aligned with the
aperture 85 whereby to position the shaft intermediate the
cylinders and in substantially parallel relationship
therewith. Accordingly, by reciprocating the pistons 75, the
cylinders move up and down causing the clamping jaws to
engage and disengage the pipe sections thereby driving the
pipe sections 43 within the soil under the foundation.
Because the pipe sections are short pipe sections,
approximately 5 feet in length, it is easy to manipulate them
in the space above the concrete floor slab 65 of the
foundation and by adding shaft sections and spacer elements
42, the solid penetrating head can be driven deep
underground, as previously described.
In order to provide protection to the people
operating the pneumatic force applying device the clamping
jaws are protected by side protecting plates 89 and a top
plate 88 interconnected together by fasteners extending
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through loops 91 of these plates. It
also keeps foreign
matter out of the clamping surfaces of the clamping jaws.
Because the piston rod ends 78 are in the form of a
fork connected to the connecting flanges 73 of the anchor
plates 71, the pneumatic force applying device can be hinged
onto the anchor plate whereby the soil penetrating head and
associated loops can be positioned into the soil at any
angle, such as the angle indicated by axis 93 in Figure 14.
Of course, the anchor plate 71 can also be secured to the top
surface 65' of the concrete floor slab 65, as also shown in
Figure 14, whereby the soil penetrating head and flexible
tubing loop can be driven into the ground along a horizontal
axis 94, as shown in Figure 14. Additionally, the pneumatic
force applying device 70 could be secured at any location
over the concrete floor slab top surface 65' by providing two
anchor plates each having a single connecting flange and
positioned to each side of a hole 95 formed in the concrete
floor slab 65. This would be desirable for example, if the
basement area has a dedicated mechanical room in which the
thermo pump is to be installed. In such an installation the
soil penetrating head 17 and its flexible tubing loop would
be driven vertically down through the hole 95, as also
illustrated in Figure 14.
Therefore, it is possible to
install the in-ground conduit system of the present invention
from inside an existing foundation with the loops being
directed at any desirable angle into the surrounding soil.
With reference now to Figure 15 there is shown how
the geothermal in-ground loop 12 of flexible tubing material
can be inserted into the soil 14 from above ground by a heavy
equipment 100 having a boom 101 to which is connected an
impact device 102 capable of applying a dynamic force against
the free end 103 of the force transmitting shaft 25, such
equipment is well known in the art. As shown in Figures 18
and 21, the loop of flexible tubing is formed by two sections
104 and 104' of such plastic tubing cut a predetermined
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length and interconnected at a free end 105 and 105' thereof
to a curved lower end section 106 of rigid plastic tubing or
metal tubing and sealingly engaged therewith.
This curved
lower end section 106 is engaged by the soil penetrating head
as illustrated in Figures 16A to 17D, namely soil penetrating
head 107 and driven into the soil by the force transmitting
shaft 25 as previously described. The soil penetrating head
107 is designed to be retracted from the soil 14 after the
head has driven the loop to a predetermined depth or has
reached the bedrock surface 18.
With reference now to Figures 16A to 17D there will
be described the construction and operation of the soil
penetrating head 107. Referring to Figures 16A to 160, there
is shown the basic construction of the soil penetrating head
107. It comprises a pair of spaced apart interconnected side
walls 108 which are preferably, but not exclusively,
constructed of steel and which are interconnected together in
spaced parallel relationship by an internal recessed tube
abutment member 109. A channel 110 is defined between the
side walls 108 in an outer peripheral portion of the soil
penetrating head 107. The channel extends along opposed side
edges 107' and the leading edge 107" thereof to receive the
lower end section 16 and immediate lower portions of the side
sections 15 and 15' therein. As
shown in Figure 160, the
tube abutment member 109 has an outer seating wall 111 which
is configured to receive the lower end section 16 of the loop
in facial contact therewith. The
rear end portion of the
soil penetrating head 107 is also provided with a transverse
slot 112 to receive the free lower end 113 of the force
transmitting shaft 25 in seated engagement therein, as better
illustrated in Figure 16A. As shown in Figure 16A, the free
end portion 114 of the force transmitting shaft 25 is
retained captive between opposed transverse slots 112 of the
opposed side walls 108.
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The free end portion 114 of the force transmitting
shaft can be welded to the opposed side walls 108 to retract
the soil penetrating head 107 after it has been driven to its
intended depth o leave the loop of flexible tubing material
buried in the soil, as shown in Figure 220. It can also be
freely seated within the opposed slots 112 whereby the force
transmitting shaft 25 can be retracted after the soil
penetrating head 107 reaches its predetermined depth to be
buried together with the lower curved end section of the
loop. Figure
22A illustrates the loop buried in the soil
together with the soil penetrating head 107. Figures 17A to
170 show how the lower section of the loop is buried into the
soil by the displacement of the soil penetrating head, Figure
170 showing the head 107 being retracted by the force
transmitting shaft 25. As herein shown, the lower section 16
of the loop is a U-shaped curved section which fits snuggly
against the outer seating wall 111 which is convexly curved.
Referring now to Figure 17D, there is shown a soil
penetrating nose member 120 which is detachably connected to
the leading edge 107" of the opposed side walls 108 of the
soil penetrating head 107 to provide ease of penetration of
the soil penetrating head into the soil while protecting the
curved lower end section 16 of the loop. The
soil
penetrating nose member is provided with a sharp leading edge
121 and a transverse locating pin 122 secured centrally
behind the apex 123 of the head. A
pair of articulated
anchor wings 124 is pivotally connected by pivot connection
125 to the forward end portion 126 to hinge rearwardly as the
soil penetrating head is driven into the soil.
This soil
penetrating nose member 120 remains in the soil under the
lower curved section 16 of the loop after the soil
penetrating head 107 is retracted. The soil penetrating nose
member is retained captive in a slot 127 provided at the apex
of the curved lower edge 107" of each of the opposed side
walls 108.
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Figure 17E shows a further embodiment wherein the
soil penetrating nose member 120' is provided with an
attachment 130 to secure same directly onto the lower curved
end section 16 of the loop of flexible tubing. Again, this
lower section 16 could be fabricated from a metal pipe or
hard industrial plastics material. The soil penetrating nose
member 120' is retained in location by the abutment member
109.
It is also made wider than the channel 110 to abut
against the outer lower edge 107" of the side walls 108. Any
pulling force in the direction of arrow 131 would cause the
wings 124 to deploy outwardly, as illustrated in Figure 17E.
With reference now to Figures 19A, 19B and 20 there
is shown a further soil penetrating head, herein soil
penetrating head 135, and as herein shown, it is formed by a
metal member 136 of V-shaped cross section 137 fabricated as
a V-shaped soil penetrating head 135 defining a pointed
leading end 138 and opposed tapered side walls 139 to provide
ease of penetration in the soil. The lower end section 16 of
the loop is formed by PVC tube sections 140 interconnected by
connectors 141, as is well known in the art.
The side
sections 15 and 15' of the loop are formed from flexible
plastic tubing such as PVC.
As herein shown, the force
transmitting shaft 25 is provided with a coupling 142, as
better illustrated in Figure 20, which consists of opposed
side walls 143, each provided with a slotted edge 144,
configured to receive therein a rear edge portion 144 of the
opposed side walls 139 of each side of the soil penetrating
head 135 for removable engagement therewith.
The coupling
142 remains in position by the provision of a channel 145
defined between the side walls 143 and which received
therebetween the lower end section 16 of the loop. After the
soil penetrating head 135 has been driven to a predetermined
depth in the soil, the force transmitting shaft and the
coupling 142 are retracted. Accordingly, it can be seen that
the soil penetrating head may have a variety of designs while
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performing the function of positioning the loop of flexible
tubing material into the soil with the head remaining in the
soil or being retracted therefrom.
The method of constructing and installing the in-
ground conduit system of the present invention whereby to
capture thermal energy stored in the ground, will be briefly
summarized. The method consists in securing a curved lower
end section of at least one loop of flexible tubing 12 to the
soil penetrating head 17. As previously described, each loop
has opposed spaced-apart elongated side sections 15 and 15'
and a curved end section 16. The side sections 16 are in the
form of large coils of tubes located above ground and as the
head is driven into the ground these coils unwind. A force
transmitting shaft is secured to coupling means of the soil
penetrating head and the force transmitting shaft is
supported at a desired angle with respect to a soil surface
adjacent a foundation of a building or spaced from the
foundation of the building or inside the foundation of the
building. The
force transmitting shaft applies a pushing
force to displace the soil penetrating head 17 in the soil
with the opposed elongated side sections of the flexible
tubing being maintained spaced-apart and being drawn into the
soil by the soil penetrating head pulling the loop and
guiding it into the soil as the head forms passages for
burial of at least a major portion of the loop together with
the soil penetrating head after the head is arrested.
Depending on the material of the flexible tubing and its
rigidity, the curved lower end section 16 of the loops 12 may
be formed several ways as previously described. Further, in
the method of installation, spacer elements 42 may be secured
to the force transmitting shaft 25 between sections thereof.
The force transmitting shaft 25 may have several forms and
can also act as a conduit for the passage of the heat
exchange liquid therethrough and in communication with the
loop of flexible tubing.
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As above described, the soil penetrating head may
have different configurations and be provided with guide
flanges to prevent deviation as it penetrates into the soil.
It may be formed of various materials such as steel,
industrial plastics or composite materials that are rigid
enough to displace small rocks as it is pushed within the
ground. The force transmitting shaft 25 can be coupled to
various impacting devices such as high frequency impactors
acting on the top end of the force transmitting shaft
sections or by a pneumatic force applying device as
previously described. Such a device can exert from 5,000 to
75,000 pounds of pressure onto the force transmitting shaft
sections. The
soil conditions for the installation of the
conduit system of the present invention must be such as to
permit the displacement of the soil penetrating head therein.
Referring to Figure 22A, there is shown a top view
of a hole made in a concrete floor slab, such as the slab 65
shown in Figures 13 and 14 and wherein several tubing loops
12 are driven into the soil under the building and at
different radiating angles as well as vertically downwards
whereby the flexible tubing loops can extend in the soil
under the foundation and within the property lines of the
building lot. Figure 22B is a side view showing some of the
tubing loops installed in a foundation excavation or through
a floor slab of an existing building at different angles and
within the lot boundary lines 150. The length of the tubes
can be calculated not to extend beyond the subterranean
property lines 150 by calculating the angle of the loop and
the distance to the property line.
Figure 22C is a further illustration showing an
installation of the in-ground conduit system of the present
invention and wherein the property lot is a small lot. As
hereinshown all of the tubing loops 12 are disposed at
different angles and radiate from a common area and at
different angles. As previously described with reference to
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Figure 14, these flexible tubing loops can be driven
horizontally and at different angles and can result in an
installation such as shown in Figure 22D wherein the property
lot is very large and therefore fewer loops may be used to
extract heat from the soil.
It is within the ambit of the present invention to
cover any obvious modifications of the preferred embodiment
described herein provide such modifications fall within the
scope of the appended claims.
