U.S. patent application number 16/698941 was filed with the patent office on 2020-06-04 for silo.
The applicant listed for this patent is Aladdin Manufacturing Corporation. Invention is credited to Thomas R. Clark.
Application Number | 20200172327 16/698941 |
Document ID | / |
Family ID | 64901862 |
Filed Date | 2020-06-04 |
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United States Patent
Application |
20200172327 |
Kind Code |
A1 |
Clark; Thomas R. |
June 4, 2020 |
SILO
Abstract
A silo for storing bulk material, the silo comprising: a
container defining an inner space, at least one supply opening for
receiving bulk material, an insert located in said inner space, the
insert having the shape of a capped cone, the bottom rim of the
insert being mechanically coupled to the inner surface of the
container, the insert having one or more openings, along its bottom
rim for allowing bulk material to pass from the upper inner space
to the lower inner space, a first group of discharge openings near
or at the lower side of the container in the surface of the
container for discharging bulk material from the lower inner space,
the top rim is provided with a second group of discharge openings
comprising at least one discharge opening for discharging bulk
material from the upper inner space, a recirculation system coupled
to the discharge openings of one of the first and second group of
discharge openings, for transporting bulk material from said
discharge openings to said supply opening, and an extraction system
being coupled to the discharge openings of the other of the first
and second group of discharge openings for extracting bulk material
towards the exterior of the silo.
Inventors: |
Clark; Thomas R.;
(Chattanooga, TN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Aladdin Manufacturing Corporation |
Calhoun |
GA |
US |
|
|
Family ID: |
64901862 |
Appl. No.: |
16/698941 |
Filed: |
November 27, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62774162 |
Nov 30, 2018 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01F 5/10 20130101; B29B
7/32 20130101; B01F 5/246 20130101; B01F 3/18 20130101; B29B 7/78
20130101; B01F 5/24 20130101; B29B 7/60 20130101; B65D 88/54
20130101 |
International
Class: |
B65D 88/54 20060101
B65D088/54 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 19, 2018 |
EP |
18213905.5 |
Claims
1. A silo for storing bulk material comprising: a container
defining an inner space; at least one supply opening for receiving
bulk material, the at least one supply opening being disposed near
or at an upper side of the container; an insert disposed within the
inner space, the insert having a shape of a capped cone with a top
side having a top rim and a bottom side having a bottom rim,
wherein: the top side of the insert is oriented towards the upper
side of the container, the bottom rim of the insert is mechanically
coupled to an inner surface of the container thereby defining,
within the container, an upper inner space above the insert and a
lower inner space below the insert, and the insert defines one or
more openings, such as one or more slits, along its bottom rim for
allowing bulk material to pass from the upper inner space to the
lower inner space; a first group of discharge openings comprising
at least one discharge opening, the openings of the first group of
discharge openings being provided near or at the lower side of the
container in the surface of the container for discharging bulk
material from the lower inner space below the insert, wherein the
top rim is provided with a second group of discharge openings
comprising at least one discharge opening for discharging bulk
material from the upper inner space above the insert; a
recirculation system coupled to the discharge openings of one of
the first and second group of discharge openings, for transporting
bulk material from said discharge openings to said supply opening;
and an extraction system being coupled to the discharge openings of
the other of the first and second group of discharge openings for
extracting bulk material towards the exterior of the silo.
2. A silo according to claim 1, wherein, the container defines the
inner space by having an upper cylindrical portion and a lower
conical portion that define the inner space.
3. A silo according to claim 2, wherein the bottom rim is
mechanically coupled to the inner surface of the container at the
transition between the upper cylindrical portion and the lower
conical portion.
4. A silo according to claim 2, wherein the bottom rim is
mechanically coupled to the inner surface of the container at a
position along the conical portion.
5. A silo according to claim 2, wherein the extraction system
comprises an extraction duct coupled to the upper rim.
6. A silo according to claim 2, wherein the upper cylindrical
portion has a diameter in the range of 6 feet to 12 feet.
7. A silo according to claim 1, wherein the silo comprises a supply
duct for supplying fresh bulk material.
8. A silo according to claim 1, wherein the volume of the upper
inner space above the insert is more than 10 times the volume of
the lower inner space below the insert.
9. A silo according to claim 1, wherein the openings along the
bottom rim of the insert have a total surface area of 4 to 15
feet.sup.2.
10. A silo according to claim 1, wherein the opening defined by the
top rim is 5 to 20% of the surface of the cross section of the
inner space defined by the plane with which the opening defined by
the top rim is coplanar with.
11. A silo according to claim 1, wherein a height of the container
above a mechanical coupling of the insert to the inner surface of
the container is between 30 and 60 feet.
12. A silo according to claim 1, wherein a height of the container
below a mechanical coupling of the insert to the inner surface of
the container is between 1 and 5 feet.
13. A silo according to claim 1, wherein the recirculation system
is coupled to the discharge openings of the first group of
discharge openings, and the extraction system is coupled to the
discharge openings of the second group of discharge openings.
14. A silo according to claim 1, wherein the recirculation system
coupled to the discharge openings of the second group of discharge
openings, the extraction system being coupled to the discharge
openings of the first group of discharge openings.
15. A method to extract bulk material from a silo, the method
comprising the steps of: providing a silo according to claim 1;
feeding fresh bulk material to said silo via a supply opening;
simultaneously discharging bulk material via the discharge openings
of the first and second group of discharge openings; and
recirculating the bulk material discharged via recirculation system
to the silo via a supply opening.
16. A method according to claim 15, wherein a volume per hour of
bulk material extracted via the extraction system substantially
equals the volume per hour of the fresh bulk material fed to the
silo via the supply opening.
17. A method according to claim 15, wherein a silo according to
claim 13 is provided, and a volume per hour ratio of a volume of
bulk material extracted via the extraction system to a volume of
bulk material recirculated via the recirculation system is in the
range of 1/1 to 1/25.
18. A method according to claim 15, wherein the bulk material are
PET flakes.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Patent
Application Ser. No. 62/774,162, filed Nov. 30, 2018 and entitled
"Silo for Storing PET flakes," and to European Patent Application
Serial No. EP18213905.5, filed Dec. 19, 2018, the disclosures of
which are hereby incorporated herein by reference in their
entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to silos suitable for storing
bulk material, such as PET flakes obtained by diminution of PET
bottles, e.g. by shredding PET bottles, and a method to store and
extract such bulk material from such silos.
BACKGROUND
[0003] PET flakes generated by shredding recycled PET bottles are
known. A disadvantage of such flakes is the possible inconsistency
in or absence of uniformity of its quality, e.g. varying
dimensions, crystallinity, and specific weight.
[0004] From e.g. EP2748358B1, such flakes are known as raw material
for BCF filament yarns, fit for making broadloom carpets. An
important aspect in the production of BCF filament yarns is
ensuring the consistency of quality of the raw material used to
feed the extrusion and spinning process.
[0005] Also, in various other storage silos fit for storing bulk
material, inconsistency of the composition of the discharged bulk
material may occur. This typically occurs when the bulk material
comprises particles with varying properties, like varying
dimensions, varying specific weight, and/or other varying physical
properties. A kind of demixing can occur in such silos.
SUMMARY
[0006] In the production of BCF from PET flakes, the quality of the
end product is often affected by the quality of the PET flakes fed
into the extruder that is used to melt the flakes into molten
recycled PET. The inventors found out that one of the key issues in
variation of the PET flakes fed, originates from the silos that the
PET flakes were stored in and extracted from in order to feed the
extruders. In one particular example, although the PET flakes were
supplied to the silos as a substantially uniform stream of flakes,
e.g., a mixture of flakes with varying individual properties but
substantially uniform properties as a mixed stream, the extracted
PET flake stream did not have such substantially uniform properties
as a mixed stream. Thus, in this example, a kind of demixing was
observed.
[0007] The inventors found that the silo, and the related methods
of running the silo according to various embodiments of the
invention, remedied this demixing effect, i.e., of PET flakes
stored in a silo, to a large extent.
[0008] According to a first aspect, a silo for storing bulk
material is provided, the silo comprising: [0009] a container
defining an inner space, [0010] at least one supply opening for
receiving bulk material being provided near or at the upper side of
the container, [0011] an insert located in said inner space, the
insert having the shape of a capped cone with a top side having a
top rim and a bottom side having a bottom rim, wherein: [0012] the
top side of the insert is oriented towards the upper side of the
container, [0013] the bottom rim of the insert is mechanically
coupled to the inner surface of the container thereby defining
within the container an upper inner space above the insert and a
lower inner space below the insert, [0014] the insert has one or
more openings, such as slits, along its bottom rim for allowing
bulk material to pass from the upper inner space to the lower inner
space; [0015] a first group of discharge openings comprising at
least one discharge opening, said openings of said first group of
discharge openings being provided near or at the lower side of the
container in the surface of the container for discharging bulk
material from the lower inner space, wherein the top rim is coupled
to a second group of discharge openings comprising at least one
discharge opening for discharging bulk material from the upper
inner space, [0016] a recirculation system coupled to the discharge
openings of one of the first and second group of discharge
openings, for transporting bulk material from said discharge
openings to said supply opening, and [0017] an extraction system
coupled to the discharge openings of the other of the first and
second group of discharge openings for extracting bulk material
towards the exterior of the silo.
[0018] According to some embodiments, the recirculation system may
be coupled to the discharge openings of the first group of
discharge openings, the extraction system being coupled to the
discharge openings of the second group of discharge openings.
[0019] According to some embodiments, the recirculation system may
be coupled to the discharge openings of the second group of
discharge openings, the extraction system being coupled to the
discharge openings of the first group of discharge openings.
[0020] According to some embodiments, the silo is a silo for
storing PET flakes. In various embodiments, the recirculation
system is coupled to the discharge openings of the first group of
discharge openings, and the extraction system is coupled to the
discharge openings of the second group of discharge openings.
[0021] PET as used herein refers to polyethylene terephthalate. The
PET flakes refer to flakes mainly comprising polyethylene
terephthalate, optionally further comprising other polymers or
copolymers.
[0022] In particular embodiments, the container is open at its top
side or is closed at its top side by means of a closing lid or
cover.
[0023] According to various embodiments, the container may define
the inner space by having an upper cylindrical part and a lower
conical part.
[0024] The silo may have a hopper-like shape. The lower conical
part is oriented such that the top of the conical shape is directed
downwards.
[0025] According to various embodiments, the bottom rim may be
mechanically coupled to the inner surface of the container at the
transition between the upper cylindrical part and the lower conical
part. As an alternative, the bottom rim may be mechanically coupled
to the inner surface of the container at a position along the upper
cylindrical part. In various embodiments, the distance between the
transition between conical and cylindrical part and the mechanical
coupling is between 0 and 1 meter.
[0026] According to various embodiments, the bottom rim may be
mechanically coupled to the inner surface of the container at a
position along the conical part.
[0027] In various embodiments, the mechanical coupling is
positioned at a height along the axis of the conical part, which
height is of between 10% and 75% of the total height of the conical
shape of the conical part, such as between 25% and 60% (e.g.
between 45% and 55%) wherein a height "being zero" along the axis
of the conical part is the position at the transition between
conical and cylindrical part.
[0028] In alternative embodiments, the bottom rim may be
mechanically coupled to the inner surface of the conical part of
the container, e.g., at a height along the axis of the conical
part, which height is in the range of 25% to 75%, such as about 50%
of the total height of the conical shape of the conical part.
[0029] According to various embodiments, the extraction system may
comprise an extraction duct. In various embodiments, this duct is
coupled to the at least one discharge openings of the first or
second group of discharge openings, as the case may be. In
particular embodiments, the extraction duct is coupled to the
upper, top rim, i.e., the upper or top rim of the insert. This
upper or top rim is in that case provided with one or more
discharge openings of the second group of discharge openings. The
upper rim may circumscribe the one discharge opening. The perimeter
of this one discharge opening may coincide with the top or upper
rim.
[0030] In various embodiments, the extraction duct intersects with
the lower conical part of the container at the top of the conical
shape of the conical lower part. The capped conical shape of the
insert, the cylindrical and conical part of the silo, and the
extraction duct may be coaxially mounted.
[0031] Alternatively, the extraction duct system comprises an
extraction duct that passes through the surface of the conical part
of the container at a position that is different from the top of
the conical shape of the conical lower part.
[0032] In embodiments where the container defines the inner space
by having an upper cylindrical part and a lower conical part,
according to some embodiments, the cylindrical part may have a
diameter in the range of 6 to 12 feet. In various embodiments, the
cylindrical part has a diameter in the range of 7 to 10 feet, such
as 8 feet.
[0033] According to some embodiments, the silo may comprise a
supply duct for supplying fresh bulk material, such as fresh PET
flakes.
[0034] According to some embodiments, one discharge opening of the
first group of discharge openings is provided at the top of the
conical part of the container. In such embodiments, the conical
part may have the shape of a capped cone, with the discharge
opening being the rim at the top of this capped conical shape.
[0035] According to some embodiments, 2 or more (e.g., at least 3)
discharge openings of the first group of discharge openings are
provided, substantially equally spread along the circumference of
the container. In various embodiments, these openings may be
provided in the wall of the conical part of the container.
[0036] In particular embodiments, the silo has 4 or more discharge
openings in its first group of discharge openings, such as 4, 5, 6,
7, 9 or even 10 discharge openings. In various embodiments, each of
these discharge openings is coupled to the recirculation system,
e.g., by its own discharge duct.
[0037] In particular embodiments, the supply opening for supplying
the fresh bulk material, such as PET flakes, is situated at the top
of the silo. This supply opening may be provided in the lid or
cover of the container, if the container has a lid or cover. The
supply opening may be coaxial with the vertical axis of the
container and/or coaxial with the axis of the capped cone shape of
the insert.
[0038] In the alternative, the container is open at its upper side.
The supply opening in such embodiments may be defined by the upper
rim of the container
[0039] According to some embodiments, the silo may comprise at
least a first supply opening coupled to the supply duct and one or
more further supply openings being coupled to the one or more
discharge openings.
[0040] Optionally, each discharge opening of the group of discharge
openings coupled to the recirculation system is coupled to its own
supply opening such that the bulk material, such as PET flakes,
from this discharge opening is transported to this one supply
opening, thereby recirculating the bulk material, such as PET
flakes.
[0041] According to some embodiments, the discharge openings of the
group of discharge openings coupled to the recirculation system may
be coupled to said at least one supply opening by means of a bucket
conveyor system.
[0042] According to some embodiments, the volume of the inner space
above the insert may be more than 10 times the volume of the inner
space below the insert.
[0043] In particular embodiments, the volume of the inner space
above the insert is more than 25 times, more than 50 times, or even
more than 100 times the volume of the inner space below the
insert.
[0044] According to some embodiments, the openings along the bottom
rim of the insert may have a total surface of between 4 and 15
feet.sup.2.
[0045] In various embodiments, the openings along the bottom rim of
the insert have a total surface of between 4 and 10 feet.sup.2.
[0046] According to some embodiments, the discharge opening of the
second group of discharge openings may be between 5 and 20% of the
surface of the cross section of the inner space defined by the
plane with which the opening defined by the top rim is
coplanar.
[0047] In particular embodiments, the area of the discharge opening
of the second group of discharge openings is between 2.6 and 10% of
the surface area of the cross section of the inner space defined by
the plane with which the opening defined by the top rim is
coplanar.
[0048] According to some embodiments, the surface area of the
discharge opening of the second group of discharge openings may be
between 25 and 75% of the surface area of the total surface area of
openings along the bottom rim of the insert.
[0049] In various embodiments, the surface area of the discharge
opening of the second group of discharge openings is between 30 and
55% of the surface area of the total surface area of openings along
the bottom rim of the insert.
[0050] According to some embodiments, the capped cone may have an
inclination angle .beta. between its surface and its axis of
between 30 and 60.degree.. In particular embodiments, the capped
cone has an inclination angle .beta. between its surface and its
axis of between 35 and 50.degree., such as 45.degree..
[0051] A silo comprising a container of which the inner space is
defined by an upper cylindrical part and a lower conical part may
have a conical part having the inclination angle .alpha. of its
surface with its axis is in the range of between 35.degree. and
70.degree., such as in a range of between 40.degree. and
60.degree..
[0052] In various embodiments, the inclination angle .alpha. of the
capped cone shape and the inclination angle of the conical part of
the container are substantially equal.
[0053] It should be understood that the inclination angle is the
smallest angle between the axis and the surface.
[0054] According to some embodiments, the height of the container
above the mechanical coupling of the insert to the inner surface of
the container may be between 30 and 60 feet. In particular
embodiments, the height of the container above the mechanical
coupling of the insert to the inner surface of the container is
between 40 and 55 feet.
[0055] According to some embodiments, the height of the container
below the mechanical coupling of the insert to the inner surface of
the container may be between 1 and 5 feet. In various embodiments,
the height of the container below the mechanical coupling of the
insert to the inner surface of the container is between 1.5 and 4
feet.
[0056] The silos according to the various disclosed embodiments
have the advantage that the demixing tendency that occurs when the
silo is in use for storing bulk material, such as PET flakes, is to
a large extent avoided.
[0057] This is especially the case when the silo is used to store
PET flakes with the recirculation system being coupled to the
discharge openings of the first group of discharge openings and the
extraction system being coupled to the discharge openings of the
second group of discharge openings. The flakes discharged from the
discharge openings under the insert are recycled and added to the
fresh PET flake stream. This stream is believed to be comprise to a
larger extent coarse and heavy flakes, which tend to move to the
side of the container, while less heavy and/or smaller particles
are believed to stay in the middle of the silo. By increasing the
heavy and/or coarse portion of the flakes, the percentage of coarse
and/or heavy flakes in the stream taken out of the silo in the
middle of the silo through the opening defined by the upper rim of
the insert will increase and come to a stable throughput of all
flakes, smaller and larger, heavier and lighter, will be
generated.
[0058] According to a second aspect, a method to extract PET flakes
from a silo is provided, the method comprising the steps of [0059]
providing a silo according to the first aspect of the invention;
[0060] feeding fresh bulk material to said silo via a supply
opening; [0061] simultaneously discharging bulk material via the
discharge openings of the first and second group of discharge
openings; and [0062] recirculating the bulk material discharged via
recirculation system to the silo via a supply opening.
[0063] According to some embodiments, the volume per hour of bulk
material extracted via the extraction system substantially equals
the volume per hour of the fresh bulk material fed to said silo via
a supply opening.
[0064] According to some embodiments, the disclosed methods may use
a silo wherein the recirculation system is coupled to the discharge
openings of the first group of discharge openings and the
extraction system is coupled to the discharge openings of the
second group of discharge openings, wherein the volume per hour
ratio of the volume of bulk material extracted via the extraction
system to the volume of bulk material recirculated via the
recirculation system is in the range of between 1/1 and 1/25.
[0065] According to some embodiments, the method uses a silo
wherein the recirculation system is coupled to the discharge
openings of the first group of discharge openings, the extraction
system is coupled to the discharge openings of the second group of
discharge openings, and the silo is used to store PET flakes,
wherein the volume per hour ratio of the volume of PET flakes
extracted via the second group of discharge openings to the volume
of PET flakes extracted via the first group of discharge openings
may be in the range of 1/25 to 1/1, in some embodiments, in the
range of between 1/20 and 1/1.25.
[0066] According to some embodiments, the PET flakes are flakes
obtained by diminution of PET bottles. This diminution may be the
shredding of PET bottles, thereby providing "recycled PET"
flakes.
[0067] The PET flakes typically have dimensions from about 4
cm.sup.2 to about 0.25 cm.sup.2. The density of the flakes may vary
widely, for example, depending on the part of the bottle from which
the flake originates. The bulk density of the flakes may vary from
between about 10 pound per cubic feet to about 25 pound per cubic
feet.
[0068] The independent and dependent claims set out particular
features of the disclosed embodiments. Features from the dependent
claims may be combined with features of the independent or other
dependent claims, and/or with features set out in the description
above and/or hereinafter as appropriate.
[0069] The above and other characteristics, features, and
advantages of the disclosed embodiments will become apparent from
the following detailed description, taken in conjunction with the
accompanying drawings, which illustrate, by way of example, the
principles of the invention.
[0070] This description is given for the sake of example only,
without limiting the scope of the disclosed embodiments. The
reference figures quoted below refer to the attached drawings.
[0071] Various embodiments are also described in the following
listing of concepts: [0072] 1. A silo for storing bulk material
comprising: [0073] a container defining an inner space; [0074] at
least one supply opening for receiving bulk material, the at least
one supply opening being disposed near or at an upper side of the
container; [0075] an insert disposed within the inner space, the
insert having a shape of a capped cone with a top side having a top
rim and a bottom side having a bottom rim, wherein: [0076] the top
side of the insert is oriented towards the upper side of the
container, [0077] the bottom rim of the insert is mechanically
coupled to an inner surface of the container thereby defining,
within the container, an upper inner space above the insert and a
lower inner space below the insert, and [0078] the insert defines
one or more openings, such as one or more slits, along its bottom
rim for allowing bulk material to pass from the upper inner space
to the lower inner space; [0079] a first group of discharge
openings comprising at least one discharge opening, the openings of
the first group of discharge openings being provided near or at the
lower side of the container in the surface of the container for
discharging bulk material from the lower inner space below the
insert, wherein the top rim is provided with a second group of
discharge openings comprising at least one discharge opening for
discharging bulk material from the upper inner space above the
insert; [0080] a recirculation system coupled to the discharge
openings of one of the first and second group of discharge
openings, for transporting bulk material from said discharge
openings to said supply opening; and [0081] an extraction system
being coupled to the discharge openings of the other of the first
and second group of discharge openings for extracting bulk material
towards the exterior of the silo. [0082] 2. A silo according to
concept 1, wherein, the container defines the inner space by having
an upper cylindrical portion and a lower conical portion that
define the inner space. [0083] 3. A silo according to concept 2,
wherein the bottom rim is mechanically coupled to the inner surface
of the container at the transition between the upper cylindrical
portion and the lower conical portion. [0084] 4. A silo according
to concept 2, wherein the bottom rim is mechanically coupled to the
inner surface of the container at a position along the conical
portion. [0085] 5. A silo according to any one of concepts 2 to 4,
wherein the extraction system comprises an extraction duct coupled
to the upper rim. [0086] 6. A silo according to any one of concepts
2 to 5 wherein the upper cylindrical portion has a diameter in the
range of 6 feet to 12 feet. [0087] 7. A silo according to any one
of the preceding concepts, wherein the silo comprises a supply duct
for supplying fresh bulk material. [0088] 8. A silo according to
any one of the preceding concepts, wherein the volume of the upper
inner space above the insert is more than 10 times the volume of
the lower inner space below the insert. [0089] 9. A silo according
to any one of the preceding concepts, wherein the openings along
the bottom rim of the insert have a total surface area of 4 to 15
feet. [0090] 10. A silo according to any one of the preceding
concepts, wherein the opening defined by the top rim is 5 to 20% of
the surface of the cross section of the inner space defined by the
plane with which the opening defined by the top rim is coplanar
with. [0091] 11. A silo according to any one of the preceding
concepts, wherein a height of the container above a mechanical
coupling of the insert to the inner surface of the container is
between 30 and 60 feet. [0092] 12. A silo according to any one of
the preceding concepts, wherein a height of the container below a
mechanical coupling of the insert to the inner surface of the
container is between 1 and 5 feet. [0093] 13. A silo according to
any one of the preceding concepts, wherein the recirculation system
is coupled to the discharge openings of the first group of
discharge openings, and the extraction system is coupled to the
discharge openings of the second group of discharge openings.
[0094] 14. A silo according to any one of the concepts 1 to 12,
wherein the recirculation system coupled to the discharge openings
of the second group of discharge openings, the extraction system
being coupled to the discharge openings of the first group of
discharge openings. [0095] 15. A method to extract bulk material
from a silo, the method comprising the steps of [0096] providing a
silo according to any one of the concepts 1 to 14; [0097] feeding
fresh bulk material to said silo via a supply opening; [0098]
simultaneously discharging bulk material via the discharge openings
of the first and second group of discharge openings; [0099]
recirculating the bulk material discharged via recirculation system
to the silo via a supply opening. [0100] 16. A method according to
concept 15, wherein a volume per hour of bulk material extracted
via the extraction system substantially equals the volume per hour
of the fresh bulk material fed to the silo via the supply opening.
[0101] 17. A method according to any one of the concepts 15 to 16,
wherein a silo according to concept 13 is provided, and a volume
per hour ratio of a volume of bulk material extracted via the
extraction system to a volume of bulk material recirculated via the
recirculation system is in the range of 1/1 to 1/25. [0102] 18. A
method according to any one of the concepts 15 to 17, wherein the
bulk material are PET flakes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0103] Having described various embodiments in general terms,
reference will now be made to the accompanying drawings, which are
not necessarily drawn to scale, and wherein:
[0104] FIGS. 1-3 are schematic diagrams of silos according to the
first aspect of the invention.
[0105] The same reference signs refer to the same, similar or
analogous elements in the different figures.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0106] Various embodiments will now be described in greater detail.
It should be noted that the term "comprising", used in the claims,
should not be interpreted as being restricted to the means listed
thereafter; it does not exclude other elements or steps. It is thus
to be interpreted as specifying the presence of the stated
features, steps or components as referred to, but does not preclude
the presence or addition of one or more other features, steps, or
components, or groups thereof. Thus, the scope of the expression "a
device comprising means A and B" should not be limited to devices
consisting only of components A and B. It means that with respect
to the claimed embodiment, the only required components of the
device are A and B.
[0107] Throughout this specification, references to "one
embodiment" or "an embodiment" are made. Such references indicate
that a particular feature described in relation to the embodiment
is included in at least one embodiment of the present invention.
Thus, appearances of the phrases "in one embodiment" or "in an
embodiment" in various places throughout this specification are not
necessarily all referring to the same embodiment, though they
could.
[0108] Furthermore, the particular features or characteristics
described may be combined in any suitable manner in one or more
embodiments, as would be apparent to one of ordinary skill in the
art.
[0109] A silo 100 for storing bulk material, in this case PET
flakes 900, is shown in FIG. 1. The silo 100 comprises a container
110 defining an inner space. The container 110 is closed at its top
side by means of a closing lid 112.
[0110] The container defines the inner space 114 by having an upper
cylindrical part 116 and a lower conical part 118. The lower
conical part 118 is oriented with its top of the conical shape
downwards. The silo 100 has a hopper-like shape. As an example, the
cylindrical part has a diameter of 8 feet. In an example, the
height of the cylindrical part may be, for example, 56 feet. The
height of the conical part may be 7 feet and the inclination angle
.alpha. is 30.degree..
[0111] The container 100 has at least one supply opening 120 for
receiving PET flake being provided at the upper side of the
container and is centrally positioned. As such the supply opening
is coaxial with the axis of the cylindrical and conical part of the
container. The silo comprises a supply duct 121 for supplying fresh
PET flakes. The supply duct for supplying the fresh and
recirculated PET flakes is situated at the top of the silo 100, in
this embodiment in the lid 112 of the container.
[0112] A first group of four discharge openings 122 are provided on
the lower side of the container 110 in the surface of the
container, in this embodiment in the conical part 118 of the
container 110. The four openings are equally distributed at the
conical part 118 of the container 110. Via a recirculation ducting
system 124, the discharge openings 122 are coupled to the supply
opening 120. In particular embodiments, this system is provided
with means (not shown) to transport the flakes using air current.
Each discharge opening 122 is coupled to its own discharge duct
126. In particular embodiments, all discharge openings 122 and the
supply duct 121 are coupled to one supply opening 120. The
discharge openings 122 may have a circular shape with diameter of,
e.g., 12 inches and the ducts 126 coupled to these openings may
have the same diameter.
[0113] The silo 100 further comprises an insert 130 located in the
inner space 114, which insert 130 has the shape of a capped cone
with a top side 132 having a top rim 134 and a bottom side 136
having a bottom rim 138. The top side 132 of the insert 130 is
oriented towards the upper side of the container 110. The capped
cone has an inclination angle .beta. between its surface and its
axis of about 55.degree.. The top rim circumscribes the one
discharge opening 133 of the second group of discharge
openings.
[0114] The bottom rim 138 of the insert 130 is mechanically coupled
to the inner surface of the container 100 by means of a limited
number of studs, e.g. 4 studs. As such an upper inner space 142
above the insert 130 and a lower inner space 144 below the insert
130 is defined. The bottom rim 138 is mechanically coupled to the
inner surface of the container 100 at the transition between the
upper cylindrical part 116 and the lower conical part 118.
[0115] In particular embodiments, the whole container and the
ducting systems are made of steel. The mechanical coupling may be a
welding.
[0116] In particular embodiments, the volume of the inner space 142
above the insert 130 is about 14 times of the volume of the inner
space 144 below the insert 130.
[0117] The insert 130 has a plurality of openings 150 along its
bottom rim 138 for allowing PET flakes to pass from the upper inner
space 142 to the lower inner space 144.
[0118] The discharge opening 133 at the top rim 134 is coupled to
the duct of an extraction system 160 for extracting PET flakes from
the upper inner space 142 towards the exterior of the silo. The
extraction system 160 comprises an extraction duct 162 coupled to
the upper rim 134 of the insert 130 while the extraction duct 162
intersects with the lower conical part 118 of the container 110 at
the top of the conical shape of the conical lower part 118.
[0119] In particular embodiments, the discharge opening 133 defined
by the top rim 134 has a diameter of 12 inches and the duct 162
coupled to this opening 133 has the same diameter.
[0120] The capped conical shape of the insert 130, the cylindrical
116 and conical part 118 of the silo, the supply opening 120, and
the extraction duct of the extraction ducting system 160 may be
coaxially mounted.
[0121] As an alternative, the bottom rim may be mechanically
coupled to the inner surface of the container at a position along
the upper cylindrical part, such that the distance between the
transition between conical and cylindrical part and the mechanical
coupling is between 0 and 3 feet.
[0122] In various embodiments, the bottom rim 138 of the insert 130
is coupled to the container with four studs positioned radially
equidistant one from the other. The openings 150 along the bottom
rim 138 of the insert 130 have a slit shape with width of about 6
inches. The total surface area of these openings is about 12
feet.
[0123] In steady state operation, the container may be filled with
PET fakes. Fresh PET flakes, e.g. flakes of PET obtained by
recycling PET bottles, are provided to the container 100 via
opening 120 and duct 121. At the bottom of the container, PET
flakes are extracted via opening 134 and duct 162, in some
embodiments at the same volume rate per hour as is applicable for
the fresh PET flake feed.
[0124] PET flakes may be recirculated by extraction through the
discharge openings 122 and recirculated to the supply opening
120.
[0125] In particular embodiments, the volume per hour ratio of the
volume of PET flakes extracted via the top rim opening 133 to the
volume of PET flakes extracted via the one or more discharge
openings 122 is in the range of between 1/25 and 1/1, in some
embodiments in the range of between 1/20 and 1/1.25. For example,
the volume per hour ratio of the volume of PET flakes extracted via
the top rim opening 133 is about 40000 pound per hour, whereas the
volume of PET flakes extracted via the discharge openings 122 is
8000 pounds per hour.
[0126] Another silo 1000 for storing PET flakes 900 is shown in
FIG. 2. The silo 1000 comprises a container 1010 defining an inner
space 1014. The container 1010 is open at its top side.
[0127] The container defines the inner space 1014 by having an
upper cylindrical part 1016 and a lower conical part 1018. The
lower conical part 1018 is oriented with its top of the conical
shape directed downwards. The silo 1000 has a hopper-like shape. In
particular embodiments, the cylindrical part has a diameter of 8
feet. The height of the cylindrical part may, e.g., be 46 feet. The
height of the conical part may, e.g., be 4 feet and the inclination
angle .alpha. may, e.g., be 45.degree..
[0128] In various embodiments, the open top of the container 1000
provides one supply opening 1020 for receiving PET flake being
provided at the upper side of the container. The silo comprises a
supply duct 1021 for supplying fresh PET flakes. The supply duct
for supplying the fresh and recirculated PET flakes is situated at
the top of the silo 1000.
[0129] One discharge opening 1022 is provided at the lower side of
the container 1010, in this embodiment at the top of the conical
part 1018 of the container 1010. Via a recirculation system 1024
comprising a bucket conveyor system 1026, the discharge opening
1022 is coupled to the supply opening 1020, being the open top of
the cylindrical part 1016. In particular embodiments, the discharge
opening has a circular shape with diameter of 12 inches.
[0130] The silo 1000 further comprises an insert 1030 located in
the inner space 1014, which insert 1030 has the shape of a capped
cone with a top side 1032 having a top rim 1034 and a bottom side
1036 having a bottom rim 1038. The top side 1032 of the insert 1030
is oriented towards the upper side of the container 1010. In
particular embodiments, the capped cone has an inclination angle
.beta. between its surface and its axis of 45.degree..
[0131] In various embodiments, the bottom rim 1038 of the insert
1030 is mechanically coupled to the inner surface of the container
1000 with four studs radially equally distant one from the other.
As such, an upper inner space 1042 above the insert 1230 and a
lower inner space 1044 below the insert 1030 is defined. The bottom
rim 1038 is mechanically coupled to the inner surface of the
conical part 1018 of the container 1000 at a height along the axis
of the conical part. In particular embodiments, such a height is
about 50% of the total height of the conical shape of the conical
part 1018.
[0132] In particular embodiments, the whole container and the
ducting systems are made of steel. The mechanical coupling may be a
welding.
[0133] The insert 1030 has 4 slit-shaped openings 1050 along its
bottom rim 1038 for allowing PET flakes to pass from the upper
inner space 1042 to the lower inner space 1044.
[0134] The one discharge opening 1033 of the second group of
discharge openings is circumscribed by the top rim 1034, which may
be coupled (e.g., on its turn) to an extraction duct system 1060
for extracting PET flakes from the upper inner space 1042 towards
the exterior of the silo. The extraction duct system 1060 comprises
an extraction duct 1062 coupled to the upper rim discharge opening
1033 of the insert 1030, where the extraction duct 1062 intersects
with the lower conical part 1018 of the container 1010 along the
side of the conical part 1018.
[0135] In particular embodiments, the opening 1033 defined by the
top rim 1034 has a diameter of 12 inches and the duct 1062 coupled
to this opening 1038 initially has the same diameter, broadening to
24 inches further downstream.
[0136] In particular embodiments, the capped conical shape of the
insert 1030, the cylindrical 1016 and conical part 1018 of the
silo, the supply opening 1020, the discharge opening 1022 of the
recirculation ducting system 1024, and the extraction duct 1062 of
the extraction ducting system 1060 are coaxially mounted.
[0137] In particular embodiments, the openings 1050 along the
bottom rim 1038 of the insert 1030 have a slit-like shape with
width of about 6 inches.
[0138] In steady state operation, the container is filled with PET
fakes. Fresh PET flakes, e.g., flakes of PET obtained by recycling
PET bottles, may be provided to the container 1000 via the opening
1020 at the top of the container and duct 1021. At the bottom of
the container, PET flakes may be extracted via opening 1033 and
duct 1062, in some embodiments at the same volume rate per hour as
is applicable for the fresh PET flake feed.
[0139] In various embodiments, via discharge openings 1022, PET
flakes are recirculated by extraction through these openings and
recycled to the supply opening 1020.
[0140] The volume per hour ratio of the volume of PET flakes
extracted via the top rim opening 1033 to the volume of PET flakes
extracted via the discharge openings 1022 may be in the range of
between 1/25 and 1/1, for example, in the range of between 1/20 and
1/1.25. In particular embodiments, the volume per hour ratio of the
volume of PET flakes extracted via the top rim opening 1033 is
about 40000 pound per hour, whereas the volume of PET flakes
extracted via the discharge openings 1022 is 8000 pounds per
hour.
[0141] It should be understood that these silos 100 and 1000 may be
used for bulk material other than PET flakes.
[0142] A further silo 2000 for storing bulk material 2900, is shown
in FIG. 3. The silo 2000 comprises a container 2110 defining an
inner space. The container 2110 is closed at its top side by means
of a closing lid 2112.
[0143] The container defines the inner space 2114 by having an
upper cylindrical part 2116 and a lower conical part 2118. The
lower conical part 2118 is oriented with its top of the conical
shape downwards. The silo 2000 has a hopper-like shape. In
particular embodiments, the cylindrical part has a diameter of 8
feet. The height of the cylindrical part may be, e.g., 56 feet. The
height of the conical part may be, e.g., 7 feet and the inclination
angle .alpha. may be, e.g., 30.degree..
[0144] The container 2000 has at least one supply opening 2120 for
receiving bulk material being provided at the upper side of the
container and is centrally positioned. As such, the supply opening
may be coaxial with the axis of the cylindrical and conical part of
the container. The silo comprises a supply duct 2121 for supplying
fresh bulk material. The supply duct for supplying the fresh and
recirculated bulk material may be situated at the top of the silo
2000, in this embodiment in the lid 2112 of the container.
[0145] In various embodiments, a first group of four discharge
openings 2122 are provided on the lower side of the container 2110
in the surface of the container, in this embodiment in the conical
part 2118 of the container 2110. The four openings are equally
distributed at the conical part 2118 of the container 2110.
[0146] The discharge opening 2122 are coupled to the duct of an
extraction system 2160 for extracting bulk material from the lower
inner space 2144 towards the exterior of the silo. The extraction
system 2160 comprises extraction ducts 2162 coupled to the
discharge openings 2122.
[0147] The silo 2000 further comprises an insert 2130 located in
the inner space 2114, which insert 2130 has the shape of a capped
cone with a top side 2132 having a top rim 2134 and a bottom side
2136 having a bottom rim 2138. The top side 2132 of the insert 2130
is oriented towards the upper side of the container 2110. The
capped cone has an inclination angle .beta. between its surface and
its axis of about 55.degree.. The top rim circumscribes one or more
discharge openings 2133 of the second group of discharge
openings.
[0148] Via a recirculation ducting system 2124, the discharge
opening 2133 is coupled to the supply opening 2120. This system is
provided with means (not shown) to transport the flakes using air
current. The discharge opening 2133 is coupled to a discharge duct
2126. In particular embodiments, the discharge openings 2133 have a
circular shape with diameter of 12 inches and the ducts 2126
coupled to these openings having the same diameter.
[0149] In various embodiments, the bottom rim 2138 of the insert
2130 is mechanically coupled to the inner surface of the container
2000 by means of one or more studs, e.g., 4 studs. In this way, an
upper inner space 2142 above the insert 2130 and a lower inner
space 2144 below the insert 2130 may be defined. The bottom rim
2138 may be mechanically coupled to the inner surface of the
container 2000 at the transition between the upper cylindrical part
2116 and the lower conical part 2118.
[0150] In particular embodiments, the whole container and the
ducting systems are made of steel. The mechanical coupling may be a
welding.
[0151] In particular embodiments, the volume of the inner space
2142 above the insert 2130 is about 14 times of the volume of the
inner space 2144 below the insert 2130.
[0152] The insert 2130 may have a plurality of openings 2150 along
its bottom rim 2138 for allowing bulk material to pass from the
upper inner space 2142 to the lower inner space 2144.
[0153] In particular embodiments, the discharge opening 2133
defined by the top rim 2134 has a diameter of 12 inches and the
duct 2126 coupled to this opening 2133 has the same diameter.
[0154] In particular embodiments, the capped conical shape of the
insert 2130, the cylindrical 2116 and conical part 2118 of the
silo, the supply opening 2120, and the part of the duct 2014 where
it is coupled to the opening 2133 are coaxially mounted.
[0155] In various embodiments, the bottom rim may be mechanically
coupled to the inner surface of the container at a position along
the upper cylindrical part, such that the distance between the
transition between conical and cylindrical part and the mechanical
coupling is, for example, between 0 and 3 feet.
[0156] In particular embodiments, the bottom rim 2138 of the insert
2130 is coupled to the container with four studs positioned
radially equidistant one from the other. The openings 2150 along
the bottom rim 2138 of the insert 2130 have a slit shape with width
of about 6 inches. The total surface area of these openings is
about 12 feet.
[0157] In steady state operation, the container may be filled with
bulk material. Fresh bulk material is provided to the container
2000 via opening 2120 and duct 2121. At the bottom of the
container, bulk material is extracted via openings 2122 and duct
2160, in some embodiments at the same volume rate per hour as is
applicable for the fresh PET flake feed.
[0158] In various embodiments, bulk material is recirculated by
extraction through discharge openings 2133 and recirculated to the
supply opening 2120.
[0159] It is to be understood that although specific embodiments
and/or materials have been described herein, various modifications
or changes may be made without departing from the scope and spirit
of this invention.
* * * * *