Note: Descriptions are shown in the official language in which they were submitted.
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PROCESS AND APPARATUS FOR MANUFACTURING A COMPOSITE FIRE
PRODUCT AND PRODUCT RESULTING THEREFROM
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims the benefits of U.S. provisional patent
application No. 61/272,127 filed August 19, 2009, which is hereby incorporated
by
reference.
TECHNICAL FIELD
[0002] The present invention relates to a process and apparatus for
manufacturing a composited fire log resulting therefrom.
BACKGROUND
[0003] Commonly available composite fire logs and fire starter logs mainly
comprise only one or two dry materials with wax or binders processed under
very
high pressures at generally ambient temperature These types of composite fire
logs are limited as to their possible BTU output as well as possible raw
materials
and moisture content of the raw materials.
[0004] Accordingly, there is a need for a process for making composite fire
logs and fire starter logs that does not require high pressures, that may use
raw
materials with high moisture content, which characteristically have not been
used
due to their low BTU value or cost of drying materials, while having a high
BTU
output.
SUMMARY
[0005] The present invention relates to a method of manufacturing a
composite fire product, comprising:
a) blending and heating materials, the materials including wax, at least one
dry material and at least one non-dry material with a moisture content of at
least 15%;
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b) compressing and heating the blended mixture, the compression pressure
being at least 500 psi and the temperature being at least 100 F; and
c) extruding the compressed mixture to form the composite fire product;
wherein at least one of the dry material and non-dry material contains
cellulose.
[0006] The present invention further relates to an apparatus for
manufacturing a composite fire product, comprising:
a first pressure chamber having a heater;
a material composition receiving input having a feeding mechanism for
providing the material composition to the first pressure chamber; and
a second pressure chamber having a temperature adjustment mechanism
and an extrusion output for providing the composite fire product, the first
and second pressure chambers being operatively connected so as to allow
material to pass therebetween;
wherein the first and second pressure chambers are configured so as to provide
a
pressure ranging from 500 psi to 25,000 psi and the heater is configured so as
to
provide a temperature of at least 100 F.
BRIEF DESCRIPTION OF THE FIGURES
[0007] Embodiments of the invention will be described by way of example
only with reference to the accompanying drawing, in which:
[0008] Figure 1 is a flow diagram of an illustrative example of the composite
fire log manufacturing process; and
[0009] Figure 2 is a schematic diagram of an illustrative example of the
composite fire log manufacturing apparatus.
DETAILED DESCRIPTION
[0010] Generally stated, the non-limitative illustrative embodiment of the
present invention provides for the manufacturing of a composite fire product
using
low BTU components having high moisture content. The non-limitative
illustrative
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embodiment also provides for a low pressure apparatus that may be used for the
manufacturing of the composite fire product. The resulting product is a dense
composite fire product with a high BTU output. This is due to the combination
of
cellulose containing materials, blending dry materials with higher moisture
content
raw materials under high flash heat allowing the materials to flow more like
liquids,
form an adhesive interacting between the various components and combine to
produce a uniform composition.
[0011] It is to be understood that the term "composite fire product" as used
throughout the following description is not meant to be limitative and that it
may
also apply to other composite fire products such as, for example, fire logs,
fire
starter logs, pellets, etc.
Manufacturing process
[0012] Referring to Figure 1, there is shown a flow diagram of an illustrative
example of the composite fire product manufacturing process. The steps of the
process 10 are indicated by blocks 12 to 19.
[0013] The process 10 starts at block 12 where the various materials are
mixed. The materials that may be used include wax (e.g. vegetable wax such as
rice, palm, soy wax, advantageously having a melting point greater or equal to
100 F, or paraffin wax with similar properties), cardboard (wax cardboard and
other waste paper), grains and spices, green residue waste (e.g. coffee
grinds, tea
leaves, sunflower hulls and stocks, waste flowers, soy bean hulls and stocks,
straw (such as wheat, barley, oats, and soragum), citrus fruit peels, corn
starch,
stocks, husks, and cob; grass (hay), sugar cane (or similar large grass
species)
and saw dust or wood residues (softwood, hardwood, wood waste trimmings;
leaves and components from spice plants, aromatic trees like cinnamon and
evergreen trees in order to provide additional nature scent). The materials
may
also include waste streams containing high moisture content (i.e. greater or
equal
to 15%) from paper such as industrial pulp and paper waste, wax boxes, failed
quality paper and wax paper batches. Further materials that may be used
include
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industrial food baking raw materials that have failed quality control testing
(flour,
sugar, starch additives), as well as waste streams from the brewing industry.
[0014] It is to be understood that other materials with characteristics
similar
to the materials mentioned above may also be used.
[0015] In a first illustrative embodiment of the present invention, the
materials include wax, at least one non-dry material having high moisture
content
(from 15 to 50%) and at least one dry material, with either or both the non-
dry and
dry materials containing cellulose.
[0016] In a second illustrative embodiment of the present invention, the
proportion of each material may vary as follows:
o wax in a proportion from about 1 to 50%;
o high moisture content non-dry materials from about 5 to 75%, the
materials having a moisture content between 15 and 50%; and
o dry materials in a proportion from about 5 to 75%.
[0017] In a third illustrative embodiment of the present invention, the
proportion of each material may vary as follows:
o wax in a proportion from about 1 to 50%;
o cardboard in a proportion from about 5 to 75%;
o green residue waste in a proportion from about 5 to 75%, containing one
or more green residue component with a moisture content between 25
and 50%; and
o saw dust or wood residue in a proportion from about 5 to 50%.
[0018] The dry materials are first mixed (i.e. cardboard, dry green residue
waste, saw dust, wood, etc.) in no specific order. The wax can be dry and
added to
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the dry material mix or melted and then added to complete the composition. The
non-dry materials can be added to the wax and heated, mixed, and kept at a
temperature greater or equal to about 100 F until used in the mix.
[0019] At block 14, the mixed materials are blended to provide a consistent
composition at ambient or elevated temperature (greater or equal to about 100
F).
The blending time, commonly from 5 to 30 minutes, is based on the specific
materials in the mixture.
[0020] Then, at block 16, the composition is compressed and heated. The
composition is compressed using, for example, a screw extruder or a packed
compression device, at a pressure ranging from about 500 psi to 25,000 psi;
advantageously under about 5,000 psi, depending on the composition and desired
product (e.g. an easy to light fire starter having a lower density, a long
lasting fire
log having a high density, etc.). The temperature during the compression is
advantageously kept greater or equal to about 100 F and depends on the
composition and the desired product as the core of the composition should be
at a
temperature greater or equal to about 120 F. The temperature typically ranges
from about 100 to 400 F. The high temperature allows for the extraction or
release
of the natural binder in the green residue waste and wood residue components,
and the pressure provides for a fluidity of the components to allow for a
production
a single mix component at the end of the process 10. The combination of high
temperature with the mixture allows the use of lower pressures to produce
higher
density components at greatly reduced energy input. The pressure and
temperature are applied to the mixed materials at flash times (i.e. below one
minute).
[0021] At block 18, the compressed composition is extruded while being
heated if a low density product is desired (for example to be formed into a
specific
shape by a further process) or cooled if a higher density product is desired
(the
cooling providing for an instant adhesive effect of the components). During
the
heated extrusion process, the temperature may range from 50 to about 75 F, the
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temperature varying with the size of die used in the extrusion, the components
used in the composition and the desired density. During the cooled extrusion
process, the temperature may range from ambient temperature to about 32 F, the
drop in temperature varying with the size of die used in the extrusion, the
components used in the composition and the desired density. The pressure and
temperature are applied to the composition at flash times (i.e. below one
minute).
The conclusion of this step results in the composite fire product with a
density
varying according to the temperature at which the composition was extruded.
[0022] Finally, at block 19, as an optional step, the shape of the composite
fire product may be modified depending on its intended use. As high density
logs
are harder to light than low density ones, at least one of the extremities of
the
composite fire product may be cut at an angle, for example between about 10
and
80 , so as to acts like a wick on a candle. This allows even a dense composite
fire
product to light easily. In an alternative illustrative embodiment, the
composite fire
product has at least one of its extremities cut at a 45 angle.
[0023] Because of the pressures used, the output of the composite fire
product manufacturing process 10 may range up to 10 tons per hour while
previous manufacturing methods using higher pressures in excess of 20,000 psi,
and comparable capacity apparatuses, provide for only up to 1.5 tons per hour.
[0024] It is to be understood that as the diameter of the produced composite
fire product increases, the duration of the compression and heating/cooling
steps
(steps 16 and 18), as well as the pressures applied, will need to be adjusted
relative to the diameter of the desired composite fire product so as to allow
for the
temperature of its core to be consistently greater or equal to about 120 F.
[0025] Typical composite fire products manufactured in accordance with the
composite fire product manufacturing process 10 of Figure 1 were evaluated in
a
standard wood stove, with the following results:
o a 0.3 oz composite fire product can burn up to about 40 minutes , with a
significant increase in BTU over that of natural wood logs;
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o a 0.5 lb composite fire product can burn up to about 2 hours , with a
significant increase in BTU over that of natural wood logs;
o a 1.0 lb composite fire product can burn up to about 3 hours , with a
significant increase in BTU over that of natural wood logs;
o a 4.0 lbs composite fire product can burn up to about 4 hours, with
significant increase in BTU over that of natural wood logs; and
o a 8.0 lbs composite fire product can burn up to about 8 hours, with a
significant increase in BTU over that of natural wood logs.
[0026] It should be noted that the composite materials of the composite fire
product burn as one unit similarly to a coal briquette, not like the prior art
products
such as fire logs, which expand and break up while burning. Also, the use of
wax
in the composition and the processing of the components of the composition
provide for composite fire products that are waterproof, therefore minimizing
oxidation of the green residue materials. Also, the burning characteristic of
the
composite fire product allows for a more complete burning of the composite
materials due to the increase BTU output (temperatures greater than 700 F),
which provides for a cleaner burn than firewood and leave less ash unlike
prior art
products.
[0027] It is to be understood that although the composite fire product
manufacturing process 10 herein described allows the use of low pressures, it
may
also be used at high pressures as well.
Manufacturing apparatus
[0028] Referring to Figure 2, there is shown the schematic diagram of an
illustrative example of the composite fire product manufacturing apparatus 100
that
may be used to implement the composite fire product manufacturing process 10
of
Figure 1. The apparatus 100 is generally composed of a blending unit 120, a
composition receiving unit 130 and two in-line temperature controlled pressure
chambers 140, 150.
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[0029] The blending unit 120 is adapted to receive the mixed materials and
is provided with a blending mechanism 122, a conveyor 124 and a heating
element 126. The conveyor 124 provides the blended composition of materials to
the composition receiving unit 130.
[0030] The composition receiving unit 130 is adapted to receive the
composition from the conveyor 124 and is provided with a feeding mechanism in
the form of a feed screw 132, which activated by motor 134, and a heating
element
136. The action of the feed screw 132 moves the composition into the first
pressure chamber 140.
[0031] The first pressure chamber 140 comprises a pressurizing mechanism
in the form of compression screw 142, which is also activated by motor 134,
and a
heating element 144. The speed of the motor 134 and the configuration of the
compression screw 142 may be adjusted in order to control the pressure applied
to
the composition. It is to be understood that the dimensions of pressure
chamber
140 also have an effect on the pressure. The action of the compression screw
142
moves the heated and pressurized composition into the second pressure chamber
150.
[0032] The second pressure chamber ' 150 comprises an extrusion output in
the form of a die 152, through which the composition is extruded, and includes
a
temperature adjustment mechanism in the form of heating/cooling element 154.
The die 152 may be adjusted depending on the desired product (e.g. fire log,
fire
starter log or pellet).
[0033] Optionally, the extrusion output may further include a slicing
mechanism so as to cut at least one of the extremities of the composite fire
product at an angle.
[0034] It is to be understood that, although not shown, the composite fire
product manufacturing apparatus 100 also includes controls and power supply
appropriate for its functioning, as known by a person skilled in the art.
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[0035] Although the present invention has been described by way of
particular embodiments and examples thereof, it should be noted that it will
be
apparent to persons skilled in the art that modifications may be applied to
the
present particular embodiment without departing from the scope of the present
invention.
