Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02771492 2014-04-04
ASPHALT RECYCLER AND HEAT MANAGEMENT APPARATUS
FIELD OF THE INVENTION
[0002] The present invention relates to a portable asphalt recycling,
asphalt management
apparatus and hauler having a high efficiency combustion chamber for recycling
asphalt and for
managing an asphalt mixture for on-site asphalt repairs.
BACKGROUND OF THE INVENTION
[0003] In repairing asphalt on a job site, often times, a cold asphalt
mixture is used to
repair damaged asphalt or to fill-in asphalt that has been removed. This cold
asphalt mixture is
generally used when large-scale hot asphalt mixtures are not warranted or
available. However,
the cold asphalt mixture generally cannot provide the variability, ease of
installation, and patch
durability that a hot asphalt mixture can provide.
[0004] Thus, a need exists for a portable asphalt recycling and asphalt
management
apparatus that allows for on-site recycling and heat management of a hot
asphalt mixture for
asphalt repair.
SUMMARY OF THE INVENTION
[0005] One aspect of the present invention includes a portable asphalt
recycling and
asphalt heat management apparatus comprising a seamless vacuum-formed one-
piece
combustion chamber that defines a fuel incubator disposed therein. A heat
accumulator is
operably coupled to the combustion chamber and a hopper assembly is operably
coupled to the
heat accumulator. The apparatus further comprises a heat distribution system
in communication
with the heat accumulator and the hopper assembly to provide heat to the
hopper assembly for
recycling used asphalt or for maintaining a hot mixture of asphalt for use in
asphalt repairs.
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= ,
[0006] Another aspect of the present invention includes a
portable asphalt recycling
and asphalt heat management system comprising a combustion chamber having a
fuel
incubator disposed therein, wherein the combustion chamber radiates heat. An
insulated
vented heat chamber or heat accumulator is operably coupled to the combustion
chamber to
collect heat that radiates from the combustion chamber. An insulated hopper
assembly is
operably coupled to the heat chamber, and a heat distribution system is
disposed within the
heat chamber and hopper assembly to distribute heat in a controlled manner for
recycling
asphalt.
[0007] Yet another aspect of the present invention includes a
combustion chamber
for use in an asphalt recycling and heat management system, comprising: a
protective cover
in the form of a shell which surrounds a one-piece, seamless and vacuumed-
formed
insulation member. The insulation member includes an exterior portion and an
interior
portion, wherein the interior portion includes a plurality of curved surface
defining a fuel
incubator. The insulation member further comprises an extension for extending
into a heat
accumulator of the asphalt recycling apparatus.
[0008] These and other features, objects and advantages of the
present invention will
become apparent upon reading the following description thereof together with
reference to
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Fig. 1 is a perspective view of an asphalt recycler and
heat management
apparatus;
[0010] Fig. 2 is a side elevational view of the embodiment
shown in Fig. 1;
[0011] Fig. 2A is a cross-sectional view of an asphalt
recycler and heat management
apparatus;
[0012] Fig. 3 is a perspective view of an asphalt hopper and
combustion chamber;
[0013] Fig. 3A is a perspective view of a combustion chamber;
[0014] Fig. 4 is a cross-sectional perspective view of an
asphalt recycler and heat
management apparatus;
[0015] Fig. 4A is a cross-sectional perspective view of a
combustion chamber;
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[0016] Fig. 4B is a side cross-sectional view of a combustion
chamber;
[0017] Fig. 4C is a side cross-sectional view of a combustion
chamber;
[0018] Fig. 5 is a bottom perspective view of an asphalt recycler
and heat
management apparatus;
[0019] Fig. 5A is a bottom perspective cross-sectional view of an
asphalt recycler
and heat management apparatus;
[0020] Fig. 6 is an exploded perspective view of an asphalt
recycler and heat
management apparatus;
[0021] Fig. 6A is a fragmentary, perspective view of an inside
wall of a hopper
assembly;
[0022] Fig. 7 is an exploded perspective view of an asphalt
recycler and heat
management apparatus; and
[0023] Fig. 7A is a fragmentary, perspective view of an inside
wall of a hopper
assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] For the purposes of description herein, the terms "upper,"
"lower," "right,"
"left," "rear," "front," "vertical," "horizontal," and derivatives thereof
shall relate to the
invention as oriented in Fig. 1. However, it is to be understood that the
invention may
assume various alternative orientations, except where expressly specified to
the contrary. It
is also to be understood that the specific devices and processes illustrated
in the attached
drawings, and described in following specification, are simply exemplary
embodiments.
Hence, specific dimensions and other physical characteristics relating to the
embodiments
disclosed herein are not to be construed as limiting, unless expressly stated
otherwise.
[0025] As shown in Fig. 1, the reference numeral 10 generally
designates an asphalt
recycler and asphalt heat management unit which, in this embodiment, is shown
as a trailer
mounted unit having a trailer 12 and a hopper 14. The present invention is
also
contemplated to be an asphalt recycler, hauler and asphalt heat management
unit that can be
mounted to a vehicle chassis, inserted in a slip-in configuration on a dump
truck, or other
like configuration that allows the apparatus to be moved to a job-site. The
hopper 14
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includes a set of access doors 16 comprised of access doors 16a and 16b for
loading asphalt.
The access doors 16a and 16b further comprise handles guides 17 for attaching
handles to
the access doors 16a and 16b and the access doors 16a and 16b are generally
hinged at their
outer edges for allowing access to the inside of the hopper 14. The access
doors 16a and
16b are operable between open and closed positions, and are shown in Fig. 1 in
the closed
position. The hopper further includes a chimney assembly 18 for venting the
hopper 14.
The hopper generally includes a front wall 30 and side walls 32 and 33 (Fig.
5). The front
wall 30 includes an angled portion 30a and side walls 32, 33, which are
substantially
symmetrical, also include angled portions 32a, 33a, which generally direct
asphalt to the
bottom wall 35 of the hopper 14. As shown in Fig. 1, the trailer 12 comprises
a set of
wheels 24 and a vehicle mounting apparatus 22 for mounting the trailer 12 to a
vehicle to
carry the unit 10 to an asphalt repair job site. As shown in Fig. 1, the unit
10 further
comprises a combustion chamber 20 which is coupled to a heat accumulator 26
for heating
the contents of the hopper 14 as further described below.
[0026] Referring now to Fig. 2, the hopper 14 further comprises a rear
wall 34 upon
which a metering door 38, see Fig. 2A, is disposed between a pair of metering
door guides
39, best shown in Fig. 5. In operation, the metering door 38 moves vertically
up and down
to allow controlled access to the inside of hopper 14, such that asphalt can
be retrieved in an
asphalt retrieval area 37 disposed above the heat accumulator 26 adjacent rear
wall 34 of
hopper 14. The asphalt retrieval area or the landing 37 is flanked on either
side by guards
36, which help contain the asphalt as it exits hopper 14.
[0027] As shown in Fig. 2A, the hopper 14 comprises a cavity 40, which is
shown in
Fig. 2A as an upwardly opening inner enclosure surrounded by a series of wall
systems.
The cavity or enclosure 40 holds an asphalt mixture (a hot mixture or cold
mix), or asphalt
to be recycled, for processing. The present invention is designed to perform
several
different functions with respect to different types of asphalt. For example,
the cavity 40 of
the hopper assembly 14 can be used to haul asphalt to a jobsite. It can also
recycle asphalt
pieces or millings to prepare a batch of hot mix asphalt. Hot mix asphalt
concrete (HMAC)
is produced at about 300 F. This high temperature serves to decrease viscosity
and moisture
during the manufacturing process, resulting in a very durable material. HMAC
is most
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commonly used for high-traffic areas, such as busy highways and airports. Warm
mix
asphalt concrete (WAM or WMA) reduces the temperature required for manufacture
by
adding asphalt emulsions, waxes, or zeolites. Cold mix asphalt concrete,
commonly referred
to as cold mix, is generally asphalt emulsified in soapy water before mixing
it with an
aggregate, thereby eliminating the need for high temperatures altogether.
However, the
asphalt produced is not nearly as durable as HMAC or WAM, and cold mix asphalt
is
typically used for low traffic areas or to patch damaged HMAC. The present
invention can
be used for all types of asphalt mix by recycling used asphalt, heating a hot
or warm asphalt
mixture to a desired working temperature (200 F- 300 F) as well as maintain a
cold mix
which also needs to be heated to approximately 100 F in order to be applied to
a repair site.
[0028] In the embodiment shown in Fig. 2, the hopper 14 comprises a
series of walls
which includes an outer wall system, a middle wall system, and an inner wall
system. As
shown in Fig. 2A, the outer wall comprises front wall 30 and angled front wall
portion 30a.
Rear wall 34 is also part of the outer wall system of the hopper 14. Middle
wall 42 is
disposed between front wall 30 and inner wall 44. Both the middle wall 42 and
inner wall
44 also have angled portions identified as 42a and 44a. Middle wall 47 is
disposed between
outer wall 34 and inner wall 48 and the rear portion of the hopper 14. A
similar
configuration is found on the side walls 32, 33 and in the angled portions of
the side walls
32a, 33a with regards to an outer wall, middle wall, and inner wall. Thus, the
hopper side
walls, front wall, and rear wall have a spaced plating configuration
consisting of an outer
wall system, a middle wall system, and inner wall system. Spaces are defined
between the
outer wall system and the middle wall system to provide insulated chambers as
further
described below. Spaces are also defined between the inner wall system and the
middle wall
system which define heated chambers as further described below.
[0029] The hopper 14 is fully insulated about the outer walls of the
enclosure.
Specifically, in the embodiment shown in Fig. 2A, insulation 50 is disposed
within insulated
chambers disposed within a space between a middle wall system and an outer
wall system of
the hopper 14 as described below. With respect to the front wall, as shown in
Fig. 2A, the
insulation 50 is held in place by insulation brackets or rails 51. The
insulation 50 is
disposed between the outer front wall 30 and middle front wall 42 as well as
between the
CA 02771492 2012-03-15
angled portions of the front wall 30a and 42a. Because of the spaced plating
configuration
of the outer wall, middle wall, and inner wall systems of the hopper 14, the
insulation is held
in place by the insulation rails 51 and helps to minimize heat loss from the
interior cavity 40
of the hopper 14 during operation. Insulation is also found in the access
doors 16a, 16b, rear
wall 34, and bottom wall 35 in a similar plating configuration as the
insulation 50 described
with respect to the front wall 30, 30a. Thus, the entirety of the hopper 14 is
insulated about
the outer wall system with insulation disposed directly adjacent the outer
wall system, as
well as within the access doors 16 and metering door 38, and adjacent the
bottom wall 35,
which is further described below.
[0030] As shown in Fig. 2A, an angled lengthwise air duct 46 is shown
which, in
this embodiment, extends from the angled portion of front inner wall 44a to
the inner wall
48 of the rear of the hopper 14. In this way, the air duct 46 extends across
the interior cavity
40 of the hopper 14 and interconnects the front portion of the hopper with the
rear portion of
the hopper, such that heated air is circulated from the front to the rear of
the hopper, thereby
providing more uniform heat distribution.
100311 In the spaced plating arrangement between the series of walls of
the hopper
14, specifically between the middle wall system and the inner wall system of
the hopper
assembly 14, a heat distribution system is disposed in the form of baffles 54,
which make up
a baffling system to control heat distribution as further described below. In
the embodiment
shown in Fig. 2A, baffles 54 are shown disposed between the inner wall and
middle wall,
such as inner wall 44, 44a and 42, 42a. The baffles 54 of the baffling system
are designed to
prevent overheating of specific areas within the interior cavity 40 of hopper
14 and,
therefore, provide evenly distributed heat to the interior cavity 40 of the
hopper 14. Heat is
generated by the combustion chamber 20, as further described below, and flows
along a path
as indicated by arrows C. As heated air exits the combustion chamber 20, it
enters the heat
accumulator or burner box 26 and is then deflected by a deflector plate 56 and
is then
directed to heat chambers or heated air passages 58 disposed within a space
between the
inner wall system and middle wall system of the hopper 14. As shown in Fig.
2A, the
heated airflow passages or sections 58 are disposed between the front middle
wall 42 and the
front inner wall 44, for example, and heated airflow sections 58 are also
disposed between
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the side walls 32, 33 in a similar manner. Air vents (not shown) are disposed
on the front
inner wall 44 and rear inner wall 48, which connect front and rear heated
airflow sections 58
via air duct 46. The deflector plate 56 deflects heat from being directly
applied to the
insulated bottom wall 35 of the hopper 14 to the heated airflow sections 58
disposed about
the front, rear, and side walls of the hopper 14 through the vents. In this
way, the heat
distribution system is in communication with the heat accumulator 26 and the
hopper 14 as
heat is produced from the combustion chamber 20. This communication is
realized thought
the vents of the heat accumulator, described below, venting heat to the heat
chambers 58 of
the hopper 14. It is further contemplated that the heat chambers 58 can be
replaced with
sealed sections that contain oil in the form of an oil jacket which is heated
by the system for
providing consistent and uniform heat to the hopper assembly 14 in operation.
Such an oil
jacket would generally be disposed in sealed sections located between the
middle and inner
walls of hopper 14.
[0032]
Turning to Fig. 3A, the hopper 14 is shown disposed above a burner box or
heat accumulator 26, wherein the burner box 26 further has a combustion
chamber 20 to
which it is operably coupled. The combustion chamber 20 comprises an exterior
metal shell
70 which has a plate 82 attached thereto configured to connect the combustion
chamber 20
to the heat accumulator or burner box 26, as further described below. As shown
in more
detail in Fig. 3A, the combustion chamber 20 has a metal exterior shell 70
comprised of a
top wall 74, side walls 75, a rear wall 78, and angled bottom wall portions
76a and 76b. A
portion of the combustion chamber 20 is disposed within the heat accumulator
26 in
assembly as further described below. The rear wall 78 of the combustion
chamber 20 has an
aperture 79 through which the combustion chamber 20 communicates with a burner
(not
shown). The burner, referred to hereinafter as a diesel burner, is connected
to the rear wall
78 of the combustion chamber 20 using apertures 73 which are configured to
engage
fasteners (not shown). The present invention can also be used in conjunction
with other
burners known in the art such as a propane burner or compressed natural gas
burner.
However, for purposes of this disclosure, the burner will be referred to as a
diesel burner
throughout this disclosure. Plate 82 of the exterior metal shell 70 of the
combustion
chamber 20 comprises apertures 73 which are configured to engaged the
fasteners (not
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shown) to connect the combustion chamber 20 to the heat accumulator 26 on a
front wall 90
of the heat accumulator 26. As shown in Fig. 3A and described in more detail
in Figs. 4 and
4A-4C, the combustion chamber 20 has an exterior metal shell 70 which
surrounds a
vacuum-formed one-piece ceramic insulation member 72, which insulates the
combustion
chamber 20 and maximizes the combustion efficiency of the combustion chamber
20 in
delivering heat to the heat accumulator 26.
[0033] As
shown in Figs. 4 and 4A, a cross section of the assembly shown in Fig. 3
is depicted. In Figs. 4 and 4A, a front portion extension 72' of the
insulation member 72 is
shown disposed within the heat accumulator 26. As shown in Fig. 4, the heat
accumulator
26 extends under the asphalt retrieval or landing area 37, such that the heat
accumulator 26
will keep asphalt disposed on the landing 37 heated for asphalt repair
application. A
deflector plate 57 disposed within the heat accumulator 26 ensures that
asphalt disposed in
the landing 37 is not super heated and also directs heat into the interior
cavity 40 of the
hopper 14 through heated air passageways 58. As further shown in Fig. 4A, the
combustion
chamber 20 comprises an interior cavity 84 which is made up of curved surfaces
that are
smooth and seamless as further described in the description of Fig. 4B.
[0034]
Turning now to Fig. 4B, a combustion chamber 20 of the present invention is
depicted having a protective covering in the form of a metal shell 70, which
comprises a top
wall 74, a rear wall 78 having an aperture 79 disposed thereon, bottom wall
sections 76a,
76b, and 76c, as well as a front wall 82 in the form of a connecting flange or
plate. The rear
wall 78 acts as a diesel burner flange for connecting the combustion chamber
20 to a diesel
burner in assembly. The
front wall 82 acts as a connector plate for connecting the
combustion chamber 20 to the front wall 90 of the heat accumulator 26 in a
configuration as
shown in Fig. 4A. Contained within the metal shell 70 of the combustion
chamber 20 is a
vacuum-formed one-piece seamless ceramic insulation member 72 that is capable
of
withstanding temperatures of 2300 F. The one-piece seamless design of the
insulation
member 72 extends from the rear wall 78 of the combustion chamber to the front
wall 82,
then extends further into the heat accumulator (not shown) approximately 3
inches by
insulation member extension 72'.
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[0035] Combustion chambers known in the art are often times fabricated by
using
multiple pieces of insulation which are seamed together using a high
temperature sealant
such as a caulk and other like adhesives to hold the insulated form. The multi-
piece
configuration of these known combustion chambers leads to failure at the seams
as heat will
breakdown the high temperature in operation. Thus, such combustion chambers
are not
designed to withstand the extreme heat required to recycle asphalt, which can
reach levels of
2300 F in the combustion chamber in order to get the asphalt millings to a
temperature of
300 F. The one-piece seamless design of the insulation member 72 of the
combustion
chamber 20 of the present invention protects against front wall burnout, which
happens
when an excessive amount of heat is conducted through the seams of a
combustion chamber
and radiates to the lower portion of a front hopper wall, causing structural
damage to the
steel of the hopper. When using the present invention, in a configuration such
as that shown
in Fig. 4, the combustion chamber 20 will not conduct heat to the angled
portion of the front
wall 30a in sufficient levels so as to cause damage to the steel of the front
wall 30a of the
hopper 14. In this way, the seamless combustion chamber of the present
invention is
capable of withstanding temperatures of up to 2300 F for recycling asphalt
without causing
heat leaks at seams which can severely damage the steel of the front wall of a
hopper. The
insulation properties of the combustion chamber 20 as well as the insulation
extension
portion 72' further add to the front wall burnout prevention measures of the
present
invention as described below.
[0036] The insulation member 72 of the combustion chamber 20 is a vacuum-
formed, one-piece seamless insulation member, which can be formed in a female
mold and
has a dense exterior portion 72a as compared to a less dense interior portion
72b. The less
dense interior portion 72b has a greater ability to retain heat and, therefore
retains the heat
emanating from the cavity portion 84 of the combustion chamber 20, such that
the exterior
portion 72a of the insulation member 72 does not get as heated. Reduced heat
in the higher
density exterior portion 72a of the insulation member 72 results in minimal
heat conducted
to the metal shell 70 of the combustion chamber 20 which, in operation,
minimizes the heat
transferred to the metal shell 70. With such minimal heat being transferred to
the metal shell
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70 of the combustion chamber 20, the front wall, such as the angled front wall
portion 30a of
Fig. 4, is protected from excessive heat which can cause damage.
[0037] The
exterior portion 72a of the insulation member 72 is generally harder than
the less dense interior portion 72b. For example, the exterior portion 72a of
the insulation
member 72 may exhibit a density, for example, of 19 pounds per cubic foot
(pc!) as
compared to a density of 13 pcf found in the less dense interior portion 72b
of the insulation
member 72. In
this way, the insulation member 72 has multiple densities which, in the
embodiment shown in Fig. 4B, is realized in a dual density configuration with
a less dense
portion 72b and a more dense portion 72a. The insulation member 72 generally
follows the
contours of the metal shell 70 and has an aperture 79' disposed near aperture
79 of the metal
shell 70 for connecting with a diesel burner. The insulation member 72 further
comprises an
aperture 81' disposed on the front end of the combustion chamber 20 adjacent
the insulation
member extension portion 72' which opens into the heat accumulator in
assembly.
[0038]
Other combustion chambers known in the art are configured using multiple
pieces of insulated material which is seamed together with high temperature
sealants such as
caulk or other like adhesives. As explained above, these configurations create
seams which
fail under the intense heat required to recycle asphalt. Further, combustion
chambers made
from multiple sections of a single insulated material do not have a multi-
density
configuration and, therefore, exhibit a common density throughout. The common
and
uniform density of these known combustion chambers means that the heat created
in the
combustion chamber is radiated from an interior side to an exterior side
without a lower
density interior portion retaining high levels of heat and a higher density
exterior portion
insulating the protective shell from excessive heat. The intense heat radiated
from the
combustion chamber through the multi-piece seamed insulation to the metal
shell of the
combustion chamber creates not only an unsafe heat transfer to the hopper, but
also a front
wall burnout effect which leads to costly repairs and continued maintenance on
the hopper
assembly. Further, multi-piece insulation systems are comparatively
inefficient due to heat
loss at the seams in operation which is not realized with the seamless
insulation member of
the present invention.
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[0039] Referring now to Fig. 4C, an insulation member 72 of a combustion
chamber
is shown wherein the insulation member 72 has an exterior high density portion
72a and an
interior low density portion 72b, thereby creating a configuration having
multiple densities,
which in this embodiment is a dual density configuration for the insulation
member 72. A
retention head (not shown) mixes air and atomized diesel fuel through a nozzle
which
circulates the air and fuel, creating a mixture which is ignited by an igniter
(not shown) near
aperture 79' of the insulation member 72. The ignited air and fuel mixture
enters into the
insulation member 72 of the combustion chamber through aperture 79' in a
direction as
indicated by arrow D. As shown in Fig. 4C, the interior portion 72b of the
insulation
member 72 has curved or rounded edges 86 which create a tumbling effect of the
ignited air
and fuel mixture, such that the curved surfaces 86 within the seamless
configuration of the
insulation member 72 define a fuel incubator 88 within the cavity 84 of the
insulation
member 72. The curved surfaces 86 of the insulation member 72 create a
tumbling effect of
the air and fuel mixture, as indicated by arrows I. The fuel incubator 88
incubates the fuel
and, therefore, retains, ignites and incubates the fuel within the cavity 84
of the insulation
member 72. In this way, a higher ratio of fuel is combusted and more
efficiently consumed
in the incubation process as compared to a straight shot of fuel into the
insulation member
72. Systems without an incubator causing a tumbling effect are less efficient
and cannot
consume all the fuel injected into a combustion chamber. This fuel ends up un-
combusted
on the system components or even on the asphalt mix itself.
[0040] The insulation member 72 of the present invention has smooth and
seamless
transitions in the form of the curved surfaces 86 disposed between all planar
portions of the
cavity or chamber 84 of the insulation member 72. The smooth seamless surface
of the less
dense portion 72b of the insulation member 72 facilitates an unencumbered flow
of
combustion within the cavity 84, and the curved surfaces 86 contribute to the
circulation of
the air and fuel in the fuel incubator 88, as indicated by arrows I, such that
there is reduced
thermal loading in any one particular area of the combustion chamber 20. By
incubating the
fuel, the fuel incubator 88 consumes fuel more efficiently and provides
extremely high heat,
all while producing low emissions. While the surface of the less dense portion
72b of the
insulation member 72 may reach temperatures of approximately 2000 to 2300 F,
the metal
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shell 70, as shown in Fig. 4B, is protected from this high heat by the higher
density portion
72a of the insulation member 72, such that the heat radiated to the outer
shell 70 is
minimized. Heat generated within the cavity 84 of the insulation member 72
exits the
insulation member 72 at aperture 81' disposed at the end of extension portion
72' in the
direction indicated by arrow E. Multi-piece combustion chambers that are
seamed together
do not have the smooth surfaces of the present invention and therefore cause
disruptions in
the air flow such that an incubation effect is not achieved.
[0041] Referring now to Fig. 5, an asphalt recycling unit 10 is shown as
removed
from a trailer apparatus and generally comprises a hopper assembly 14, a heat
accumulator
or burner box 26, and a combustion chamber 20. The hopper 14 includes outer
side walls
32, 33, which have angled portions 32a, 33a, a rear wall 34, and a front wall
30 (not shown).
The hopper 14 includes a set of access doors 16 comprising left and right
access doors 16b
and 16a. The rear wall 34 comprises a metering door 38 which has metering door
guides or
rails 39, which guide the metering door vertically in a direction as indicated
by arrow F. In
operation, the metering door 38 is operable between open and closed positions,
shown in the
closed position in Fig. 5, such that the metering door can be opened
vertically to a select
height for accessing asphalt disposed within the hopper assembly 14. Further,
hopper
assembly 14 can be tilted at an angle to urge the asphalt mixture processed
therein toward
the metering door 38 for dispensing the asphalt mixture onto the asphalt
mixture retrieval
area or landing 37. This tilting effect can be caused by a hydraulic system
incorporated into
the hopper assembly 14, or the asphalt recycling unit 10 can be mounted on a
dump truck
bed wherein the truck supplies the apparatus for tilting the hopper 14.
[0042] As shown in Figs. 5 and 5A, the combustion chamber 20 is operably
coupled
to the heat accumulator 26. The insulation member 72 of combustion chamber 20
includes
an extension portion 72 CI which is disposed within the heat accumulator 26.
The extension
72' of the insulation member 72 extends into the heat accumulator 26 such that
the heat
accumulator burner flange 82 remains insulated from the heat of the combustion
chamber 20
as shown in Fig. 3A. In this way, the angled portion of the front wall 30a of
the hopper
assembly 14 also remains insulated from heat exiting the combustion chamber 20
such that a
minimal amount of heat radiates to the front wall 30a in operation.
Surprisingly, the
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extension portion 72' of the insulation member 72 need only extend into the
heat
accumulator 26 approximately 3 to 4 inches to effectively deter heat transfer
to the front
wall 32a of the hopper 14. By releasing the extreme heat generated in the
combustion
chamber 20 approximately 3 to 4 inches away from the front wall flange 82 into
the heat
accumulator 26, the extension 72' of the combustion chamber helps prevent
against front
wall burnout and surprisingly increases the efficiency heat production to the
hopper 14.
[0043] As shown in Figs. 5 and 5A, the heat accumulator 26 comprises a
box-type
configuration having a rear wall 92, a front wall 90, side walls 94, 95, and a
bottom lip or
rim 96. In full assembly, the bottom rim 96 supports an insulated pan (not
shown) which
closes off the heat accumulator during operation. The heat accumulator 26
further
comprises a top wall 93, which also forms the bottom wall 35 of the hopper 14.
The heat
accumulator 26 is fully insulated about the side walls 94, 95 and front and
rear walls 90, 92
by insulation panels 97, as well as on the top wall by insulation panels 99.
The insulation
panels 97, 99 disposed on the top wall, side walls, bottom pan, and front and
rear walls
create an insulation blanket which allows for more heat to be held in the heat
accumulator
26 which translates into controlled movement of large amounts of heat into the
heat airflow
sections 58 of the apparatus. The heat accumulator 26 includes a cage-like
support structure
102 which surrounds the top wall 93, side walls 94, 95, and front and rear
walls 90, 92, such
that the insulation panels 97 are disposed between the cage-support structure
102 and the
walls of the heat accumulator 26. The bottom pan (not shown) which rests on
the bottom
rim 96 of the heat accumulator 26 is also insulated, such that the heat
accumulator 26 is
insulated on all sides. The heat accumulator 26 further comprises vents 100,
which vent
heat accumulated therein to the heated airflow sections 58 of the hopper
assembly 14.
Horizontal heat deflector plate 56 deflects heat to the front wall, rear wall
and side walls of
the hopper assembly 14 in operation, and vertical heat deflector plate 57
controls the amount
of heat sent to the asphalt retrieval landing 37. Insulation panels 99 also
insulate the hopper
14 adjacent the bottom wall 35.
[0044] As shown in Figs. 6 and 7, a hopper assembly 108 is depicted in an
exploded
view wherein the hopper assembly 108 is similar to the hopper assembly 14
described in
Figs. 1-5. The hopper assembly 108, shown in Figs. 6 and 7, comprises a series
of spaced-
13
CA 02771492 2012-03-15
apart plating shells or wall systems which include an inner wall system 110, a
middle wall
system 114, and an outer wall system 118. The inner wall system 110 comprises
a baffling
system having baffles 112 disposed within heated airflow sections 158. The
heated airflow
sections 158 are defined by the space between the inner wall system 110 and
the middle wall
system 114 in assembly. The middle wall system 114 comprises insulation rails
116 which
support insulation panels that insulate the hopper assembly 108 in insulated
chambers 150,
which are formed between the outer wall system 118 and the middle wall system
114. In
assembly, the hopper 108 is operably coupled to a heat accumulator 126, which
has an
aperture 124 disposed on the front wall of the heat accumulator 126 for
coupling the heat
accumulator 126 to a combustion chamber 120. The combustion chamber 120
further
includes an extension 122 comprised of insulated material which extends into
aperture 124
of the heat accumulator 126, such that heat is released from the combustion
chamber 120
into the heat accumulator 126 in a manner that insulates the outer wall system
118 of the
hopper 108 from excessive heat accumulation. The heat accumulator 126 further
comprises
vents 130 which direct heat from the combustion chamber 120 into the heated
airflow
sections 158 of the hopper assembly 108.
[0045] As shown in Figs. 6A and 7A, a baffle system comprised of baffle
members
112 is disposed in the heated airflow sections 158 defined by space between
the inner wall
system 110 and middle wall system 114 (not shown) for evenly distributing heat
to the
hopper assembly. Air heated within the heated airflow sections 158 rises
through gas
passages 113 disposed within the baffles 112. In this way, the heated air is
evenly
distributed throughout the heated airflow sections 158, such that, in
operation, the baffles
112 slow the heat movement and control the heat distribution within the heated
airflow
sections 158. The result is an evenly distributed heating system for the
hopper assembly,
such that localized overheating of asphalt material contained within the
hopper is avoided.
[0046] In a recycling operation, pieces of previously cured asphalt can
be loaded into
the volume of the cavity portion 40 of the hopper 14 of the present invention,
as shown in
Fig. 4. A diesel burner (not shown) is then initiated to feed a fuel and air
mixture to the
combustion chamber 20 where the mixture is ignited. The fuel and air mixture
incubates in
the fuel incubator 88 (Fig. 4C) of the combustion chamber 20 and heat produced
from the
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CA 02771492 2014-04-04
combustion chamber 20 is expelled into the heat accumulator 26 where it is
then deflected by the
deflection plates 56, 57 to the heated air passages 58 of the hopper assembly
14. The heated air
moves in a controlled uniform manner through the baffles 54 (Fig. 2A) of the
baffling system
disposed within the heated air passages 58 of the hopper assembly 14 to heat
the asphalt pieces
in a controlled manner such that localized overheating of the asphalt
materials is prevented in
any one area. The time it takes to recycle a load of asphalt depends on the
age of the material,
density of the material and the ambient air temperature. The typical asphalt
recycling procedure
is to load the hopper at the end of the workday, add rejuvenator as necessary,
set the timer on the
burner to start the burner at a predetermined time during the night, and when
operators arrive for
work the next morning a load of hot mix asphalt should be ready for use.
[0047]
The scope of the claims should not be limited by the preferred embodiments set
forth in the examples, but should be given the broadest interpretation
consistent with the
description as a whole.
