U.S. patent application number 17/313732 was filed with the patent office on 2021-08-19 for close packing briquet shapes.
The applicant listed for this patent is The Clorox Company. Invention is credited to Stefan Brown, Stephen Fisher, Joshua Long, Donald Swatling.
Application Number | 20210253967 17/313732 |
Document ID | / |
Family ID | 1000005568122 |
Filed Date | 2021-08-19 |
United States Patent
Application |
20210253967 |
Kind Code |
A1 |
Long; Joshua ; et
al. |
August 19, 2021 |
CLOSE PACKING BRIQUET SHAPES
Abstract
Briquet designs that facilitate close packing and improve burn
efficiency are provided herein. Such designs can include scaled
down briquet size and close packing shapes, which can include
pyramidal shaped portions, such as rectangular pyramids and
tetrahedron shapes, as well as oblate spheroid and hexoid shapes,
to facilitate closer random packing when the briquets are randomly
arranged in a pile when poured from a bag. Some briquet shapes can
further include special surface features, such as flattened or
rounded portions or depressions, such as dimples, that reduce
volume without increasing the bulk density in order to further
improve burn performance and efficiency.
Inventors: |
Long; Joshua; (Pleasanton,
CA) ; Fisher; Stephen; (Pleasanton, CA) ;
Swatling; Donald; (Pleasanton, CA) ; Brown;
Stefan; (Pleasanton, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
The Clorox Company |
Oakland |
CA |
US |
|
|
Family ID: |
1000005568122 |
Appl. No.: |
17/313732 |
Filed: |
May 6, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
16149337 |
Oct 2, 2018 |
11034904 |
|
|
17313732 |
|
|
|
|
62568274 |
Oct 4, 2017 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A47J 37/079 20130101;
A47J 37/0768 20130101; C10L 5/36 20130101; C10L 5/00 20130101; C10L
5/361 20130101 |
International
Class: |
C10L 5/36 20060101
C10L005/36 |
Claims
1. A briquet comprising: a solid combustible fuel formed in a
shape, wherein the shape is defined to allow for close-packing at a
density of 450 to 3,000 briquets per cubic foot when a plurality of
briquets of like shape are randomly arranged within a randomly
poured pile, wherein the shape comprises a generally spheroidal
shape having a pair of semi-spheroidal portions extending from
opposite sides of a mid-plane portion such that that the briquet is
symmetrical about the mid-plane portion and an apex region of each
semi-spheroidal portions is flattened or compressed toward the
mid-plane portion.
2. The briquet of claim 1, wherein the shape is defined so that a
volume of each briquet is within a range between 0.2 to 2 cubic
inches.
3. The briquet of claim 1, wherein each of the semi-spheroidal
portions comprises a plurality of curved faces extending towards
the apex region.
4. The briquet of claim 3, wherein the plurality of curved faces
meet the mid-plane portion at smooth rounded edges such that the
briquet has a substantially continuous surface.
5. The briquet of claim 1, wherein the mid-plane portion comprises
a circle.
6. The briquet of claim 1, wherein the mid-plane portion comprises
a regular polygon with five or more sides.
7. The briquet of claim 6, wherein the polygonal mid-plane portion
is a hexagon.
8. The briquet of claim 6, wherein each of the semi-spheroidal
portions comprises a plurality of ridges, each ridge extending from
a corner of the polygonal mid-portion to the flattened apex
region.
9. The briquet of claim 1, wherein each of the flattened apex
portions comprises an upper-third or less of the respective
semi-spheroidal portion.
10. A close packing briquet comprising: a solid combustible fuel
formed in a shape, wherein the shape comprises a pair of
semi-spheroidal portions extending from opposite sides of a
mid-plane portion such that that the briquet is symmetrical about
the mid-plane portion, wherein an apex region of each
semi-spheroidal portions is flattened or compressed toward the
mid-plane portion, wherein the briquet is shaped and dimensioned to
facilitate close packing when a plurality of briquets of like shape
are randomly arranged within a randomly poured pile.
11. The briquet of claim 10, wherein the shape comprises a volume
within a range from 0.20 to 2.0 cubic inches.
12. The briquet of claim 11, wherein close packing comprises a
density of 450 to 3,000 briquets per cubic foot.
13. The briquet of claim 10, wherein each of the semi-spheroidal
portions comprises a plurality of curved faces extending towards
the apex region.
14. The briquet of claim 13, wherein the plurality of curved faces
meet the mid-plane portion at smooth rounded edges such that the
briquet has a substantially continuous surface.
15. The briquet of claim 10, wherein the mid-plane portion
comprises a circle.
16. The briquet of claim 10, wherein mid-plane portion is a regular
polygon having five or more sides.
17. The briquet of claim 16, wherein mid-plane portion is a
hexagon.
18. The briquet of claim 16, wherein each of the semi-spheroidal
portions comprises a plurality of ridges, each ridge extending from
a corner of the polygonal mid-portion to the flattened apex
region.
19. The briquet of claim 10, wherein the flattened apex portion is
defined along an upper third or less of the respective
semi-sphereoidal portion.
20. The briquet of claim 10, wherein the shape is defined so a
total number of edges within the randomly poured pile is within a
range from 5,000 to 15,000 inches per cubic foot.
Description
CROSS-REFERENCE
[0001] This application is a continuation of U.S. application Ser.
No. 16/149,337 filed Oct. 2, 2018, which claims the benefit of
priority of U.S. Provisional Application No. 62/568,274 filed Oct.
4, 2017. The content of each of the above-referenced applications
are hereby incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] This application generally relates to solid fuel briquets
used for heating or cooking. In particular, the invention pertains
to briquet shapes that provide improved ignition and burn
characteristics.
[0003] There is considerable consumer interest in using charcoal
briquets for outdoor cooking in which meals can be prepared and
served quickly for individuals or large groups. Consumers desire
cooking and grilling with charcoal briquets that are readily
stackable to form the traditional starter pile, easily ignitable,
maintain a uniform and efficient combustion that ignites the
individual briquets in the starter pile, and have a sufficiently
long burn period. Similarly, consumers prefer to minimize handling
of dirty charcoal when forming traditional starter piles and the
like.
[0004] Conventional charcoal briquets are often configured in a
generally pillow-shape. This configuration provides for both
reasonable ease of manufacturing by the supplier, and handling by
the consumer. Pillow-shaped briquets are typically used for cooking
on the grill or the like by using briquets stacked within a mounded
or conical configuration or pile usually by pouring the briquets
from a bag onto a grill substrate or the like. Then lighter fluid
is often added, and followed by igniting the briquets with an
ignition source.
[0005] An "ignition phase" follows, as burning proceeds from the
surface of the briquet, and a gray ash is formed on a significant
portion of the briquet until a majority of the exposed surfaces
have ignited, and burning has progressed inwardly toward the
intended area of the briquets. Thus, completion of the ignition
phase of burning is identified by the formation of visible ash on
the briquet.
[0006] At this point, the briquets are spread out under the grill
or the like, and they continue to burn with intense heat suitable
for cooking and grilling throughout a "burn phase". For maximum
performance of the briquets, it is desirable that the ignition
phase be limited in time so that the briquets may be used for
cooking or grilling fairly quickly, so that the duration of the
burn phase is optimized and extended to a suitable cooking or
grilling time.
[0007] There has been some previous work in the ornamental and
geometrical configuration of charcoal briquets. For example, U.S.
Des. 389,453 to Mitchell et al. describes a charcoal briquet having
a groove generally in the shape of the letter "K", and U.S. Pat.
No. 4,496,366 to Peters describes charcoal having a briquet, or
other geometric configuration, purportedly to achieve desired
lighting and burn characteristics. In another example, U.S. Pat.
No. 6,074,446 to Fujino describes charcoal having a plurality of
air passing portions or grooves in its body purportedly to supply
combustion air inside the charcoal body while burning.
[0008] However, previously known ornamental and geometrically
configured charcoal briquets fail to address ignition and burn
phase characteristics of the briquets associated with randomly
arranging the briquets in a pile when poured from a bag. Previously
known charcoal briquets intended for rapid ignition and delivery of
intense heat have used combinations of various configurations and
compositions, typically examining the burn characteristics of
briquets individually. However, very rapid delivery of intense heat
often does not provide an acceptable combustion response for
cooking or grilling purposes. Previous teachings have failed to
address or resolve the effect of briquet shapes on the arrangement
of briquets within a pile when randomly poured from a bag of
briquets. Therefore, there exists a need for briquet designs and
shapes that improves random arrangement of the briquets to enhance
ignition and burn characteristics, thereby improving performance
and efficiency.
BRIEF SUMMARY OF THE INVENTION
[0009] The present invention relates to briquet designs and shapes
that facilitate random close packing and/or improved burn
performance as compared to conventional briquets, in particular
pressed briquets for grilling.
[0010] In one aspect, a briquet formed of a solid combustible fuel
in a defined shape is provided. In some embodiments, the shape is
defined to allow a briquet packing density of 450 to 3,000 briquets
per cubic foot when a plurality of briquets of like shape are
randomly arranged within a randomly poured pile. In some
embodiments, the shape is defined so that a volume of each briquet
is within a range between 0.2 to 2 cubic inches, or, in some
embodiments, 0.25 to 1.8 cubic inches. In some embodiments, the
shape is defined so a total number of edges within the randomly
poured pile is within a range from 5,000 to 15,000 inches per cubic
foot. In some embodiments, the shape can include one or more
surface features comprising 35% or less of the a total surface area
of the briquet. Such surface features can include a dimple,
depression or other indentation.
[0011] In another aspect, briquets defined as close packing shapes
are provided. Such briquets can include a solid combustible fuel
formed in shape that includes one or more polygonal pyramidal
portions dimensioned to facilitate close packing when a plurality
of briquets of like shape are randomly arranged. In some
embodiments, the shape is of a volume within a range from 0.25 to
1.8 cubic inches, 0.5-1.8 cubic inches, 0.8-1.8 cubic inches,
1.0-1.8 cubic inches, or 1.3-1.8 cubic inches. In some embodiments,
the shape is of a volume within a range from 0.25 to 1.5 cubic
inches, 0.5 to 1.5 cubic inches, 0.8 to 1.5 cubic inches, or 1.0 to
1.5 cubic inches. In some embodiments, close packing refers to a
packing density within a range of about 450 to 3,000 briquets per
cubic foot when randomly arranged within a poured pile. In some
embodiments, the briquets are shaped so as to facilitate close
packing of 500-3,000; 600-3,000; 700-3,000; 800-3,000; 900-3,000;
1,000-3,000; 1,500-3,000; 2,000-3,000; or 2,500-3,000 briquets per
cubic foot. Some embodiments are shaped to facilitate close packing
within a range of 450-2,500; 450-1,500; 500-2,000; 600-1,500;
700-1,000; or 700-900 briquets per cubic foot.
[0012] In some embodiments, a briquet having a close packing shape
is formed such that the base of each of a pair of pyramidal
portions extends from a mid-plane portion of the briquet such that
the briquet is symmetrical about the mid-plane. In some
embodiments, the mid-plane portion is a square with rounded
corners. The square of the mid-plane can include inwardly rounded
sides and each of the pyramidal portions can include a surface
feature along an apex of the respective pyramidal portion. The
surface feature can include a circular dimple, hole or other
indentation. In some embodiments, the pyramidal portions can
include smoother or rounded edges such that the top and bottom
surface of the briquet are a substantially continuous surface.
[0013] In some embodiments, the pyramidal portions extend from the
base that is perpendicular to the mid-plane, the pyramidal portion
being defined by can be defined by opposing triangular portions of
top and bottom halves of the briquet. In such embodiments, the
height of the pyramidal portion extends along the horizontal
mid-plane of the briquet. In some embodiments, the shape is formed
such that the apex of the opposing portions is off-center. Such a
configuration facilitates manufacture by providing a trailing face
that is more shallow than a leading face of the briquet during a
press-roll manufacturing process, which aides in release of the
briquet from a pocket of the press rollers.
[0014] In still other embodiments, the close packing shape can
include an oblate spheroid shape or an oblate hexoid shape. Such
shapes can further include a surface feature, such as a dimple or
other indentation.
[0015] These and other objects and advantages are achieved by the
present invention which comprises briquet shapes that allow for
random close packing, thereby enhancing ignition properties and
burn phase characteristics. Such shapes can any of the shapes or
designs described herein, and can further include one or more
special surface features as described herein to further reduce
volume and improve burn efficiency.
[0016] These and other objects and advantages of the present
invention will become apparent from the following description of
the preferred embodiments of the invention, taken together with the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIGS. 1A-1D illustrates an example briquet shape having
improves close packing properties, in accordance with some
embodiments of the invention;
[0018] FIGS. 2A-2D illustrates another example briquet shape having
improves close packing properties, in accordance with some
embodiments;
[0019] FIG. 3 shows an example close packed briquet density in a
random pour stack associated with briquet shapes in accordance with
some embodiments;
[0020] FIGS. 4A and 4B show graphs of briquet attributes that
provide improved burn performance over conventional briquet
designs;
[0021] FIGS. 5A and 5B show 3D plots that illustrates the impact on
% EOI of briquet volume and bulk density or of pile edges and bulk
density, respectively;
[0022] FIGS. 6A and 6B shows one factor plots of volume versus BBQT
and briquet packing density versus BBQT, respectively;
[0023] FIG. 7 shows burn efficiency of select briquet designs of
some embodiments as compared to conventional briquet designs;
[0024] FIGS. 8A-8B shows burn characteristics per weight of select
briquet designs of some embodiments as compared to conventional
briquet designs;
[0025] FIGS. 9A-9D illustrates another example briquet shapes
having improved close packing properties in accordance with some
embodiments;
[0026] FIGS. 10A-10D illustrates another example briquet shape
having improved close packing properties in accordance with some
embodiments;
[0027] FIGS. 11A-11D illustrates another example briquet shape
having improved close packing properties in accordance with some
embodiments;
[0028] FIGS. 12A-12D illustrates another example briquet shape
having improved close packing properties, in accordance with some
embodiments;
[0029] FIGS. 13A-13D illustrates another example briquet shape
having improves close packing properties in accordance with some
embodiments;
[0030] FIGS. 14-16 illustrate example briquet designs having
tetrahedron shapes with close packing properties in accordance with
some embodiments;
[0031] FIGS. 17A-17D illustrate an alternative briquet design of an
oblate spheroid shape with close packing properties in accordance
with some embodiments;
[0032] FIGS. 18A-18D illustrate an alternative briquet design of an
oblate spheroid shape with close packing properties in accordance
with some embodiments; and
[0033] FIGS. 19A-19D illustrate an alternative briquet design of an
oblate hexoid shape with close packing properties in accordance
with some embodiments.
DETAILED DESCRIPTION OF THE INVENTION
[0034] In one aspect, the present invention pertains to shapes that
improve any of the following attributes: (i) ease of ignition
(EOI), a measure of how easily the charcoal ignites (percentage of
ash on briquet at 10 minutes); (ii) time to cooking readiness
(TTCR), a measure of how quickly the charcoal gets to 70% ash
(time-based measurement); (iii) time to 380.degree. F. (TT380), a
measure of how quickly the charcoal gets to 380 F (time-based
measurement); (iv) time over 380 F (TO380), a measure of how long
the charcoal burns over 380.degree. F. (time based measurement);
(v) peak charcoal temperature (PCT), a measure of the peak
temperature that the charcoal hits during the course of the burn
(temperature measurement); and (vi) BBQT/LB--the TO380 of the burn
divided by the lbs. of charcoal used for the burn (this new metric
was developed to quantify efficiency of burn as it relates to
TO380).
[0035] Various features of a charcoal briquet that drive each
attribute were identified and models were created for each
attribute. These models allowed for determination of shapes of the
briquet that deliver substantial improvements in burn performance.
These models were ultimately used to develop various close packing
briquet shapes, including those described herein. These shapes
deliver improved lighting performance (EOI/TTCR/TT380) without
sacrificing TO380 and while using less overall product as compared
to conventional designs. While shape depicted in FIG. 1 is
particularly advantageous from both a performance, manufacturing
and aesthetic standpoint, there are various other shapes that can
also deliver similar performance benefits, such as any of those
described herein. For example, as long as the shapes meet the
constraints in FIG. 4, such shapes can provide improved performance
as compared to conventional briquet designs.
[0036] In regard to the improved performance of close packing
shapes, it is theorized that the bulk density formed by these
shapes, particularly when randomly poured from a bag, improves burn
performance for various reasons. Typically, close packing allows
for more burnable material in a fixed volume, thereby raising the
peak temperature and therefore extending TO380. Also, the closer
surface areas of briquet may better transfer heat from one briquet
to the other which means less heat is lost or cooled to the ambient
air thereby extending burn temperatures. In addition, tighter
formation may restrict air flow or be close to stoichiometric
conditions. It is appreciated that the advantages of the close
packing shapes described herein are not limited by any of the above
noted theories and that the surprising advantages and improved
performance of the disclosed shapes and designs have been shown by
performance testing, as detailed herein.
[0037] Table 1, shown below, outlines the attributes that drive
briquet performance, as well as the associated benefits for each
attribute. Additionally, this table contains a range for each
attribute where performance is improved as compared to conventional
briquets. It is appreciated that various attributes are dependent
on certain other attributes such that selection of one attribute
will affect selection of another attribute. For instance, setting
the briquet volume will dictate the necessary range for bulk
density. The terms "Lower" "Higher" indicates which direction the
attribute should trend for the intended benefit.
TABLE-US-00001 TABLE 1 Attributes of Shapes Facilitating Improved
Performance by Close Packing Benefit Lights Ready Burns Faster
Faster More Faster (EO/ (TTCR/ Efficiently Peak Smaller Less
Solvent Attribute Range Units TTCR) TT380) (BBQT) Temp Package
Brokens Absorption Smaller 0.25-1.8 in.sup.3 Lower Lower Lower
Lower Lower Lower Briquet Volume Airflow Higher TBD Higher Bulk
Density Lower Lower Lower Higher Higher Briquets/f.sup.3 450-2978 #
of Higher Higher Higher Higher Higher briquets Total Pile 9320- In
Higher Higher Edges 11256" Aspect Ratio Surface 0-.32 % Higher
Higher Less Higher Feature to Total Surface Area
[0038] In developing improved briquet shapes that allow for close
packing between briquets, a number of factors were examined,
individually and in combination. These factors included: briquet
volume, Briquet Functional Surface Area/Total Surface Area,
Functional Surface Area (e.g. area of a special feature), Briquet
Edge Length/Total Surface Area, Aspect Ratio, Pressure Drop of Air
Across a Briquet Pile, Bulk Density, Briquets/ft.sup.3. It is
appreciated that some of the factors can correlate with certain
other factors, for example, smaller briquets correspond with
smaller volumes, which corresponds to increased
briquets/ft.sup.3.
[0039] Various shapes were devices to facilitate close packing of
adjacent briquets when randomly poured from a bag, while
controlling for one or more of the above factors. Examples of these
shapes are provided herein. It is appreciated that various
modifications of these shapes can be made while still retaining the
advantages of the concepts described herein. The shapes described
herein were laboratory tested for EOI, TTCR, TO380, PCT, BBQT/lb
and were tested under typical outdoor conditions for TO380, PCT,
and BBQT/lb. Experimental models of test responses are presented
below in Table 2. The differing briquets that were tested were
utilized the same charcoal formulation and tested under tightly
controlled conditions in the laboratory testing so that differences
in burn characteristics were clearly attributable to the given
shape. The tested briquets included a control of a conventionally
shaped briquet formed of the same charcoal formulation.
TABLE-US-00002 TABLE 2 Identified design experiment models of test
responses from division laboratory (DL) and outdoor bums (OD)
DL-EOI = DL-TO380 = DL-BBQT = OD =TO380 = OD-BBQT = 23.11 35.22
18.88 24.84 7.07 -27.96 * D -18.87 * D -9.87 * D -13.06 * D -3.95 *
D -7.81 * H 4.56 * J 3.71 * G 0.82 * G -7.48 * J 4.80 * J D Volume
G Aspect Ratio H Air Flow (in H20) J Bulk Density (lbs/ft.sup.
3)
[0040] The above design experiment models above illustrate several
relationships. In one aspect, lower briquet volume generally leads
to higher EOI, but higher bulk density and airflow pressure drop
generally leads to lower EOI. Typically, lower volume leads to a
higher bulk density and airflow pressure drop. Therefore, in order
to optimize EOI, the volume of the briquet should be minimized
without increasing the bulk density or pressure drop within the
pile. Thus, in addition to defining the briquet in a shape that
facilitates close packing, burn characteristics can be further
improved by including a special surface feature that reduces the
volume of the briquet without increasing bulk density. In some
embodiments, this special feature comprises a depression or
recessed portion (e.g. dimple, hole, indent, etc.). Preferably, in
embodiments having pyramidal shaped portions, the special feature
can be a depression or dimple formed along where an apex of the
pyramidal portion would be. It is understood that the dimple could
be circular or formed in various shapes and depths. Utilizing a
special surface feature along this location retains the close
packing benefits of the steeper faces of the pyramidal shaped
portion, while reducing the volume of the briquet without
substantially increasing bulk density or pressure drop within a
pile of randomly poured briquets. Such configurations substantially
improve burn characteristics as compared to conventional shaped
briquets, such as a pillow-shape having substantially shallow,
curved faces along top and bottom portions.
[0041] In another aspect, lower volume briquets typically leads to
a higher BBQT or TO380/1b, which means the product burns more
efficiently. Thus, utilizing smaller volume briquets can lead to
more efficient burns. It should be noted that as the volume of the
briquets becomes too small, inefficiencies in manufacturing can
arise and, at some point, the air flow through can be adversely
impacted adversely affecting burn performance. Therefore, it is
beneficial to balance this attribute with the benefits of various
other attributes, including ease of manufacture and handling. In
some embodiments, the briquets are substantially smaller (e.g. less
than 80%, typically about 60% or less) than a standard sized
conventional pillow-shaped briquet (e.g. 2'' by 2'' square
pillow-shaped briquet).
[0042] In still another aspect, lower volume briquets, coupled with
a higher bulk density, typically leads to a higher TO380. A higher
bulk density leads to a higher TO380 because there is more mass in
the burn. As noted above, this factor can be balanced with other
factors described herein in order to provide an optimally sized and
shaped briquet.
[0043] In view of the above, lighting attributes (EOI, and
subsequently TTCR and TT380) can be maximized by minimizing the
volume of the briquet without significantly increasing the bulk
density or packing density (which directly relates to pressure
drop) of the briquet pile. Therefore, smaller briquets that have
special surface features (e.g., dimples) that minimize the bulk
density of the pile should provide improved lighting performance
over current briquets. Along these lines, various shapes have been
developed that provide for closer packing when randomly poured into
a pile.
[0044] In one aspect, the present invention pertains to shapes that
allow for random close packing of briquets within a pile when
poured by a consumer from a bag. In contrast to approaches that
require specifically arranging briquets, this approach pertains to
the random arrangment of briquets that occur when merely poured
from a bag into a pile. Providing close packing of adjacent
briquets within such a randomly arranged pile substantially
improves burn efficiency. In some emodiments, such close packing
shapes include a polygonal pyramid and shapes having polygonal
pyramid portions. Typically, such polygonal pyramidal portions are
square pyramid or tetrahedrons, although it is appreciated that in
some embodiments, the polygonal base of the pyramid could include
five or more sides. In some embodiments, the faces of the pyramidal
portions are steeper than the faces of conventional shaped
briquets, such as standard pillow-shaped briquets. In a
conventional pillow shape, the top and bottom surfaces are
generally curved and have an aspect ratio of about 2:1 or greater,
the briquet being substantially convexly curved along the entire
top and bottom surfaces and having substantially straight sides
along the horizontal mid-plane. In contrast, in various close
packing shapes, the steepest portion of the inclined top and bottom
faces have an aspect ratio of about 1:1. In some embodiments, the
close packing shapes include inwardly curved, or concave portions
along the edges of the horizontal mid-plane. The inward curve along
each edge can extend partly along the top and bottom faces
extending from the horizontal mid-plane edges. In some embodiments,
the close packing shape can further include a special feature to
further improve burn characteristics. The special feature can
include any feature that reduces volume and increases surface area.
In some embodiments, the special feature includes a depressed or
recessed portion, such as a dimple, along where an apex of the
pyramidal portion would be.
[0045] FIGS. 1A-1D depicts an example briquet shape 10 having
square pyramidal portions 12 extending from horizontal mid-plane
portion 11. The mid-plane portion is generally rectangular in shape
such that each of the opposing pyramidal portions 12 is a
rectangular pyramid. In this embodiment, the mid-plane is generally
square in shape. The mid-plane includes a flattened ridge 11, which
is a feature typical of manufacturing the briquet by press-rollers,
the ridge being located along where the press-rolls interface. In
this embodiment, the edges of the pyramidal portion are rounded or
contoured such that each of the top and bottom surfaces of the
briquet form a substantially continuous surface. In this
embodiment, the steepest portion of the inclined surface of the
pyramidal portion, as seen in FIG. 1B, has an aspect ratio of about
1:1. In this embodiment, the square mid-plane has inwardly curved
edges 13 from which the faces of the pyramidal portion extend. As
can be seen in FIG. 1D, the faces of the pyramid alternate between
being convex (adjacent the rounded corners of the square mid-plane
portion) and being concave (along the inwardly curved edges 13 of
mid-plane). The faces of the pyramid transition as the faces
approach the apex to an outwardly curved plane towards a top of the
pyramidal portion. In this embodiment, the briquet further includes
a special feature 15 defined as a recessed circular dimple along
the apex of the pyramidal portion. In this embodiment, the dimple
is formed as a circular recessed portion with rounded, contoured
edges to facilitate ease of manufacturing the briquet by press
rolling.
[0046] FIGS. 2A-2D depict another example briquet shape 20 having
pyramidal portions 22 extending from horizontal mid-plane portion
21. In this embodiment, the mid-plane portion is triangular such
that each pyramidal portion is a triangular pyramid or tetrahedron.
Similar to the previous embodiment, the mid-plane portion includes
a flattened ridge 21 to facilitate manufacture of the briquet by
press-rollers. In this embodiment, the triangular pyramids are
defined such that the apex is offset from a center of the
triangular mid-plane portion 21. This results in formation of two
steeper faces 22a along a leading side during manufacture by press
rollers and a larger, more shallow side 22b along a trailing side
of the briquet, as seen in FIG. 2D. This configuration facilitates
manufacture of the briquet by press-rolling as the larger, more
shallow face 22b provides a larger surface against which the
press-rollers engage to push the briquet for release from between
the pair of rollers. In addition, the larger surface reduces
stresses and potential damage to the briquet during release. In
this shape, a majority of the briquet defines another pyramidal
portion having a height along the mid-plane portion (see FIG. 16).
While in this embodiment there is no special surface feature
included, it is appreciated that such a feature could be included
along various locations to reduce the volume without increasing the
bulk density to further improve burn performance.
[0047] FIG. 3 illustrates a random close packed pile of briquets
formed by pouring multiple briquets from a bag onto a substantially
planar surface (e.g. grill grate or substrate). The briquet shapes
described herein allows adjacent briquets to more closely pack as
compared to conventional briquet designs. In one aspect, pyramidal
shapes generally provide closer packings that conventional briquet
shapes, such as a pillow shape. While a purely pyramidal shape may
be desirable for close packing, such shapes include sharp corners
and apex such that manufacturing briquets in such shapes can be
challenging and damage to briquets can occur during shipping and
handling. Thus, such shapes can be utilized by forming briquets in
shapes that generally approach pyramidal shapes or include
pyramidal portions.
[0048] Ideally, each briquet shape is defined in a close packing
shape such that when poured into a randomly arranged pile, as shown
in FIG. 3, the pile has a briquet density 33 within a range of 450
to 3,000 briquets/ft.sup.3. It is understood that the ideal density
of briquets also depends on the volume of each individual briquet.
It is appreciated that the briquet packing density within that
range depends in part on the volume of individual briquets. In some
embodiments, a bag of briquet may include multiple shapes and/or
sizes of briquets, for example, multiple sizes of like shapes,
multiple shapes, or multiple sizes and shapes. In some embodiments,
the sizes and shapes of briquets are selected so as to be
complementary to provide a close packing arrangement when randomly
poured.
[0049] FIGS. 4A and 4B depict graphs that shows combinations of
briquet volumes and bulk densities or combination of pile edges and
briquet packing density, respectively, that provide improved
performance over conventional pillow-type briquet designs, as
indicated in the highlighted yellow area at left. The design of
FIG. 1 falls into the identified yellow ranges in each of FIGS. 4A
and 4B and shows improved lighting performance over the
conventional design without sacrificing burn time. Table 3 below
shows the burn performance of the design of FIG. 1 as compared to
the control (conventional pillow-shape design). Table 4 below shows
the briquet packing densities provided by the improved briquet
designs of FIGS. 1 and 16 as compared to typical conventional
pillow-type briquet designs.
TABLE-US-00003 TABLE 3 Burn Performance of Improved Design as
Compared to Control Design Row Labels Average of VA10 Average of
TO380 Control 47.8 42.4 Design of FIG. 1 53.0 42.8 Grand Total 50.4
42.6 *Improved design has 7.5% less mass than control design
TABLE-US-00004 TABLE 4 Briquet Packing of Improved Designs as
Compared to Conventional Designs Avg. Volume Brio/ft.sup.3 Data
Product (in.sup.3) Rep 1 Rep 2 Rep 3 Rep 4 Rep 5 Average
Conventional 1.89 221 217 212 210 430 Shape 1 Design of 1.34 351
352 351 703 FIG. 1 Design of 1.07 444 442 886 FIG. 16 Conventional
2.08 196 192 192 197 201 391 Shape 2 *Each rep is 0.5 ft.sup. 3
[0050] FIG. 5A depicts a graph that shows specifically how % EOI
changes with both volume and bulk density. FIG. 5B depicts a graph
that shows specifically how % EOI changes with both bulk density
and pile edges. The flag on each chart represents the conventional
charcoal briquet product The chart clearly shows that lower volume
or pile edges combined with a lower bulk density provide
significant advantages over the conventional briquet product.
[0051] FIG. 6A shows a graph that highlights how BBQT (T0380/min)
is impacted by briquet volume, which was the primary significant
factor for BBQT. FIG. 6B shows a graph that highlights how BBQT
(T0380/min) is impacted by briquet packing density. The blue line
in each graph shows the volume of the conventional charcoal briquet
product. The graphs indicates that briquet volumes smaller than the
typical size of conventional briquets and increased briquet packing
density provide more efficient burn. In this case, the less
material can be used than in the conventional shape while
maintaining the same TO380. Thus, when combining the close packed
shapes described herein with smaller volumes can provide even more
advantages and improvements in burn efficiency as compared to
conventional design.
[0052] FIG. 7 depicts a graph showing the advantages close packing
shapes over the conventional design for burn efficiency. The
efficiency of a burn, or BBQT/lb (TO380/lb of a product) is a
function of the burn weight that is used. This chart demonstrates a
few key points of the inspirational shapes that were initially
tested. Specifically, all test shapes show a higher BBQT/lb versus
the control shape at an equal weight, which means that at a
constant weight, the products burn longer than the conventional
product, or at a specific lower weight they can have a parity
BBQT/lb to the conventional product. The modified shapes described
herein demonstrate substantially more efficient burn
characteristics. In some embodiments, the modified shapes can
include one or more surface features that further improves the
BBQT/lb. As an example, the small pillow has a smaller volume than
the 75% control, so theoretically it should have a higher
efficiency. However, the addition of surface features in the 75%
control drives its BBQT/lb higher than that of the small pillow
design.
[0053] FIGS. 8A-8B depict graphs showing the burn performance of
shapes from the additional testing. As seen in FIG. 8A, at a lower
burn weight, all shapes from additional testing have an improved
EOI (e.g. improved lighting) versus control. As seen in FIG. 8B, at
a lower burn weight, all shapes have a parity to higher BBQT/lb
(e.g. burn efficiency) versus control. It is noted that the test
shapes were of a smaller volume than the control.
[0054] FIGS. 9A-18 depict alternative briquet shapes that provide
random close packing and improved burn efficiency. FIGS. 9A-9D
depicts example briquet 90, which has similar features as the
embodiment in FIG. 1A, except the special surface feature 95 has
sharper edges and sidewalls. FIGS. 10A-10D depict example briquet
100, which has similar features as the embodiment in FIG. 1A,
except the special surface feature 15 is defined as an irregular,
off-center depression and facilitate random arrangement within a
close packed pile. FIGS. 11A-11D depicts example briquet 110, which
has similar features as the embodiment in FIG. 1A, except the
special surface feature 115 is defined as a square depression. Such
a configuration may further reduce the volume of each individual
briquet.
[0055] FIGS. 12A-12D depict example briquet 120, which has similar
features as the embodiment in FIG. 1A, except the special surface
feature 125 is defined as an irregular, off-center depression,
which may and facilitate random stacking within a close packed
pile.
[0056] FIGS. 13A-13D depict example briquet 130, which has similar
features as the embodiment in FIG. 1A, except the pyramidal
portions 132 are more shallow, having an aspect ratio greater than
1:1, typically about 2:1. Such a configuration further reduces the
volume and material in each briquet, but retains some of the
advantages of the pyramidal shape, the inwardly curved sides of the
mid-plane portion and the special surface feature dimple. While
various features are described herein, it is appreciated that any
of the features described herein could be utilized in any
combination or can be modified in accordance with the concepts and
principles described herein.
[0057] FIG. 14 depicts a tetrahedron briquet 140 having planar
faces 141, which optimizes the close packing aspect of the shape,
as described previously. While such shapes allow for closer packing
than curved designs, particularly pillow-shaped briquets, such
tetrahedron shapes are difficult to manufacture utilizing
conventional methods, such as press-rolling. Therefore, to improve
manufacturability, one or more portions can be rounded so as to aid
in removal or discharge of the briquet from the press roll, for
example as shown in the embodiment of FIG. 15.
[0058] FIG. 15 shows a briquet formed in a rounded tetrahedron
shape 150 that includes special surface feature 155 defined by a
rounded portion of the apex while the shape retains substantially
planar faces 151. The rounded portion 155 may aid in release of the
briquet from the pocket of the press-roll in which the briquet is
formed and improve manufacturability. It is further appreciated
that various other portions, include edges between planar faces
could be rounded or contoured as well.
[0059] FIG. 16 depicts a modified tetrahedron 160 with a design
that further improves manufacturability. In this design, similar to
that of FIGS. 2A-2D, the mid-plane portion 161 extends between two
tetrahedrons 162 so that, in combination, a substantial majority of
the briquet forms a pyramidal shape (shown pointing upward in FIG.
16). While this modified tetrahedron shape substantially retains
the close packing attributes of the tetrahedron, the orientation of
the tetrahedrons in regard to the mid-plane portion aids in release
of the briquet from the pocket of the press-roller since there is
less material friction due to reduced depth in the pocket of the
press rollers assembly. This feature also improves
manufacturability by allowing more pockets/briquets to be included
on the insert of the press-rollers.
[0060] FIGS. 17A-18D depict briquets having a generally oblate
spheroidal shape. FIGS. 17A-17D depict an oblate spheroid 170
having a mid-plane portion 171 extending along a major axis of the
oblate spheroid between convexly curved spheroid halves 172. Such
shapes further improve manufacturability as the shape readily
releases from the half spheroid pockets of the press-rollers.
Spheroid briquet 170 can further include special surface features
176 in one or both sides, shown here as two indents or depressions
in a top side, to further reduce the volume of each briquet. Such
features facilitate a random close pack pile when randomly poured.
It is understood that the oblate spheroid can be without any
special surface features or can include various other surface
features as well. FIGS. 18A-18D similarly depict a briquet having
an oblate spheroid shape 180 in which the mid-plane portion 181 is
circular and extends between spheroid halves 182. It is appreciated
that either of these briquet design can further include one or more
surface features comprising 35% or less of the a total surface area
of the briquet, for example, a dimple, depression or other
indentation.
[0061] FIGS. 19A-19D depict a briquet having an oblate hexoid
shape. As shown, the oblate hexoid briquet 190 includes a mid-plane
portion 191 defined as a hexagon, from which six faces 182 extend
and curve to approximate or approach a spheroidal shape. It is
appreciated that this briquet design can further include one or
more surface features comprising 35% or less of the a total surface
area of the briquet, for example, a dimple, depression or other
indentation.
[0062] While the exemplary embodiments have been described in some
detail, by way of example and for clarity of understanding, those
of skill in the art will recognize that a variety of modifications,
adaptations, and changes may be employed. Hence, the scope of the
present invention should be limited solely by the appending
claims.
[0063] In the foregoing specification, the invention is described
with reference to specific embodiments thereof, but those skilled
in the art will recognize that the invention is not limited
thereto. Various features, embodiments and aspects of the
above-described invention can be used individually or jointly.
Further, the invention can be utilized in any number of
environments and applications beyond those described herein without
departing from the broader spirit and scope of the specification.
The specification and drawings are, accordingly, to be regarded as
illustrative rather than restrictive. It will be recognized that
the terms "comprising," "including," and "having," as used herein,
are specifically intended to be read as open-ended terms of
art.
* * * * *