U.S. patent application number 09/284983 was filed with the patent office on 2002-09-19 for combustible fuel source.
Invention is credited to MANNER, D. LEE.
Application Number | 20020129808 09/284983 |
Document ID | / |
Family ID | 4159247 |
Filed Date | 2002-09-19 |
United States Patent
Application |
20020129808 |
Kind Code |
A1 |
MANNER, D. LEE |
September 19, 2002 |
COMBUSTIBLE FUEL SOURCE
Abstract
The combustible fuel source of the invention includes a body
comprising a porous carrier and a solid fuel. When combustion is
established the fuel is vaporized and combusted on one or more
surfaces of the body, In the internal part of the body the solid
fuel vaporized and the vaporized fuel moves through the porous
carrier to one or more surfaces of the body wherein it is
combusted. A portion of the heat resulting from this combustion
maintains the vaporization of the solid fuel for continued
combustion. A variety of materials can be used as the porous
carrier, including combustible materials such as paper fibres,
cloth, pulp fibres, powdered coal or charcoal and non-combustible
materials such as ground pumice, sand or ceramic materials. A
variety of solid fuels can be used, including paraffin wax, beeswax
and other waxes or wax-like materials derived from animal and/or
vegetable processing. The body can be shaped into preselected
shapes according to an intended use and/or can be placed into
stoves or other heating devices as a fuel source.
Inventors: |
MANNER, D. LEE; (ONTARIO,
CA) |
Correspondence
Address: |
GOWLING STRATHY & HENDERSON
COMMERCE COURT WEST
SUITE 4900
TORONTO
M5L1J3
CA
|
Family ID: |
4159247 |
Appl. No.: |
09/284983 |
Filed: |
May 11, 1999 |
PCT Filed: |
November 13, 1997 |
PCT NO: |
PCT/CA97/00857 |
Current U.S.
Class: |
126/45 |
Current CPC
Class: |
C10L 5/40 20130101; C10L
11/02 20130101; Y02E 50/30 20130101; C10L 11/04 20130101 |
Class at
Publication: |
126/45 |
International
Class: |
F24C 005/04 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 13, 1996 |
CA |
2,190,233 |
Claims
We claim:
1. A combustible fuel source comprising: a porous carrier including
at least one surface for a combustion site; and a solid fuel
impregnated into said porous carrier such that, when ignited at
said at least one surface by an ignition means, said solid fuel is
combusted and heat from said combustion vaporizes additional solid
fuel in said porous carrier which travels through said porous
carrier to said at least one surface wherein it is combusted.
2. A fuel source according to claim 1, wherein said porous carrier
is not combustible.
3. A fuel source according to claim 2, wherein said granular
material is selected from the groups comprising crushed pumice,
sand and powdered coal.
4. A fuel source according to claim 1, wherein said porous carrier
is combustible.
5. A fuel source according to claim 4, wherein said porous carrier
comprises cloth fibres.
6. A fuel source according to claim 4, wherein said porous carrier
comprises cellulose fibres.
7. A fuel source according to claim 6, wherein said cellulose
fibres are dried paper pulp.
8. A fuel source according to claim 6, wherein said cellulose
fibres are short strand wood fibres.
9. A fuel source according to claim 6, wherein said cellulose
fibres are long strand wood fibres.
10. A fuel source according to claim 6, wherein said cellulose
fibres are wood fibres from the processing of wood fibre fluff.
11. A fuel source according to claim 1, wherein said porous carrier
is formed into a preselected shape.
12. A fuel source according to claim 11, wherein said preselected
shape is substantially conical.
13. A fuel source according to claim 11, wherein said preselected
shape is a pellet and said porous carrier is short stranded wood
fibres.
14. A fuel source according to claim 1, wherein said fuel source
further comprises a combustion initiating means adjacent said at
least one surface.
15. A fuel source according to claim 14, wherein said combustion
initiating means comprises a wick which is ignited to initiate
combustion of said solid fuel.
16. A fuel source according to claim 14, wherein said fuel source
further comprises an ignition means adjacent said combustion
initiating means such that ignition of said ignition means ignites
said combustion initiating means which, in turn, initiates
combustion of said solid fuel.
17. A fuel source according to claim 1, wherein said solid fuel is
selected from the group comprising paraffin wax, beeswax, wax
derived from animal products and wax derived from vegetable
products.
18. A fuel source according to claim 1, wherein said solid fuel is
selected from the group comprising petroleum wax, motor oil and
grease
19. A fuel source according to claim 1, wherein said fuel source is
formed into a preselected shape in the form of a cylinder and said
fuel source further comprises an outer sheath which is denser
relative to said porous carrier and said outer sheath is
impregnated with a solid fuel.
20. A fuel source according to claim 1, wherein said porous carrier
further comprises powdered material selected from one or more of
the following waste material: railway ties, telephone poles,
creosote, powdered coal, calcium oxalate-solids, krofta fines, or
bark.
21. A fuel sources according to claim 1, wherein said fuel source
is an insect repellent.
22. A fuel source according to claim 1, wherein said fuel source
may be spread over an oil spill in the water and combusted together
with said oil spill.
23. A stove comprising: a shell having a substantially open surface
and ventilation means to introduce air to a combustion site within
said stove; a fuel source within said shell and including a porous
carrier whose upper surface acts as a combustion surface and a
solid fuel impregnated into said porous carrier such that, when
ignited at said at combustion surface said solid fuel is combusted
and heat from this combustion vaporizes additional solid fuel
within said porous carrier which travels through said porous
carrier to said combustion surface wherein it is combusted.
24. A stove according to claim 21, wherein said porous carrier
comprises cellulose fibres.
25. A stove according to claim 21, wherein said cellulose fibres
comprise dried paper pulp.
26. A stove according to claim 21, wherein said solid fuel is
selected from the group comprising paraffin wax, beeswax, wax
derived from animal products and wax derived from vegetable
products.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a combustible fuel source.
More specifically, the present invention relates to a novel
combustible fuel source which is relatively clean burning, safe and
environmentally friendly.
BACKGROUND OF THE INVENTION
[0002] Combustible fuel sources abound and include a wide range of
sources, from the common, such as fire wood, to the high tech such
as the solid fuel rockets. While many combustible fuel sources
exist, it is desired to have a substantially clean burning fuel
source which is inexpensive, safe, convenient to use and which uses
readily available materials.
[0003] It is also desirable to use high temperature combustion
burning to destroy waste products which pose a threat to the
environment. In particular, high temperature combustion of
environmentally hazardous or detrimental waste is desirable if it
can be accomplished with minimal acceptable emissions.
SUMMARY OF THE INVENTION
[0004] According to a first aspect of the present invention, there
is provided a combustible fuel source comprising:
[0005] a porous carrier including at least one surface for a
combustion site; and
[0006] a solid fuel impregnated into said porous carrier such that,
when ignited at said at least one surface by an ignition means,
said fuel is combusted and said combustion causes additional fuel
to travel through the porous carrier to said at least one surface
wherein said additional fuel is combusted.
[0007] In an aspect of the invention, said porous carrier may be
combustible materials, such as cellulose or dried paper pulp,
cloth, or pulp fibres.
[0008] According to another aspect of the invention, the porous
carrier may be noncombustion materials such as pumice, sand or
ceramic material.
[0009] In another aspect of the invention, the porous carrier is
formed into a preselected shape depending on its intended purpose
and required combustion characteristics. The preselected shape will
to a large extent depend on its intended purpose. Examples of
suitable preselected shapes include cones, rings, blocks, powdered
granules or pellets, candles, balls and sticks.
[0010] According to a further aspect of the present invention,
there is also provided a thin layer of a combustible fuel source
that is applied to an object. The thin layer of combustible fuel
source provides a heat source for that object.
[0011] In another aspect of the invention, a combustible fuel
source is provided which further comprises a combustion initiating
means. In a particular embodiment of the invention, the combustion
initiating means may comprise a combustion wick which is ignited to
initiate combustion of said fuel source.
[0012] In another aspect of the invention, said fuel source further
comprises an ignition means adjacent said combustion initiating
means such that ignition of said ignition means ignites said
combustion initiating means which, in turn, ignites said solid
fuel.
[0013] In a further aspect of the invention, a combustible fuel
source is provided which further comprises waste material or
recovery blends which are combusted together with the solid fuel
source. Examples of such waste material include railway "ties",
telephone poles, creosote, calcium oxalate, powdered coal, waste
material from the forestry and pulp and paper industries, and
sludge wastes from wastewater treatment plants.
[0014] In another aspect of the invention, there is provided a
combustible fuel source which can be applied to an oil spill in the
water to combust said oil spill.
[0015] In another aspect of the invention, there is provided a
combustible fuel source which can be burned in a low ventilated
container to create a low burning smoke which acts as an insect
repellent.
[0016] In another aspect of the invention natural waste products
may be incorporated into the combustible fuel sources. In
particular, garden waste, including natural fibres such as leaves,
pine needles, grass clippings and natural cloth fibres may be
incorporated into the porous carrier or natural wastes produced
from industrial processing, such as fish fat from fish processing
plants, or animal fat from slaughter houses could be incorporated
into the solid fuel.
[0017] According to another aspect of the present invention, there
is provided a stove comprising:
[0018] a shell having a substantially open surface and ventilation
means to introduce air to a combustion site within said stove;
[0019] a combustible fuel source within said shell and including a
porous carrier whose upper surface acts as a combustion surface and
a solid fuel impregnated into said porous carrier such that when
the combustible fuel source is ignited at said combustion surface
said solid fuel is combusted on the upper surface and heat from
this combustion vaporizes additional solid fuel within said porous
carrier which additional fuel travels through said porous carrier
to said combustion surface wherein it is combusted.
[0020] In another aspect of the present invention, there is
provided a combustible porous carrier comprising a porous carrier
and a solid fuel comprising a wax, paraffin wax, beeswax, animal or
vegetable shortening/fat product.
[0021] In a further aspect of the present invention, there is
provided a combustible porous carrier comprising a porous carrier
with a solid fuel comprised of a petroleum product such as motor
oil and grease blended with fat products including petroleum
wax.
[0022] The term "solid fuel" means all fat sources, including oils.
Generally the liquid oils are solidified by blending the oils with
a denser fat source such as wax. However, the liquid oils may be
used without solidifying them. A liquid oil will be absorbed by a
wood/paper fibre porous carrier and complete the process of
combustion appropriately in accordance with the present invention.
A liquid oil may be employed for a specific purpose.
[0023] The term "impregnated into said porous carrier" includes,
among other things, coated, saturated, covered, permeated and any
other means of combining the fuel source with the porous carrier to
achieve a combustible fuel source of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Preferred embodiments of the present invention will now be
described, by way of example only, with reference to the attached
Figures, wherein:
[0025] FIG. 1A is an illustration of a combustible fuel source in
accordance with an embodiment of the present invention;
[0026] FIG. 1B is an illustration of an inverted conical
combustible fuel source of an embodiment of the present invention
and an illustration of a cylindrical combustible fuel source of an
embodiment of the present invention in which the process of fuel
vaporization and combustion is illustrated.
[0027] FIG. 2 is an illustration of a combustible fuel source in
accordance with another embodiment of the present invention;
[0028] FIG. 3 is an illustration of shows a section taken through
line 3-3 of FIG. 2;
[0029] FIG. 4 is an illustration of a partially cut away
combustible fuel source in a stove in accordance with another
embodiment of the present invention;
[0030] FIG. 5 is an illustration of a combustible fuel source in
accordance with another embodiment of the present invention for use
in wood or coal furnaces and the like; and
[0031] FIG. 6 is an illustration of an improved match which
includes a fuel source in accordance with another embodiment of the
present invention;
[0032] FIG. 7 is an illustration of a combustible fuel source
applied as a thin layer to a cooking pot in accordance with another
embodiment of the present invention.
[0033] FIG. 8 is an illustration of a wood pellet combustible fuel
source in accordance with another embodiment of the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0034] In FIG. 1A there is illustrated an embodiment of the
combustible fuel source in accordance with the present invention.
The combustible fuel source is indicated generally at 20. The
combustible fuel source 20 is shown resting on support surface 27.
Fuel source 20 comprises a body 24 formed of a porous carrier and a
solid fuel. The exposed surface 26 on the body 24 is where the
combustion largely takes place and is termed the combustion
surface.
[0035] As used herein, the term `porous` is intended to comprise
any carrier structure which is substantially porous to vapours of
the vaporized solid fuel permitting vapours from solid fuel which
is vaporized within body 24 to move to the exterior of body 24 to
combustion surface 26.
[0036] As shown in FIG. 1A, in a present embodiment, body 24 is
shaped in the general form of a truncated cone and includes, at the
apex of the cone, a combustion initiating means, such as wick 28,
and an ignition means, such as a safety match 32 which is partially
embedded into body 24 adjacent wick 28.
[0037] It should be noted that wick 28 is only provided to ease the
initiation of combustion of fuel source 20 and wick 28 need not be
provided in circumstances wherein other means of initiating
combustion of fuel source 20 are available. In fact, when provided,
wick 28 is generally quite short in length and will only burn for a
relatively short period of time. Similarly, safety match 29 is only
provided as a convenience and safety match 29 need not be provided
in circumstances wherein other means of igniting fuel source 20 are
available.
[0038] It should also be noted that fuel source 20 is not limited
to a body of generally conical shape and other shapes may be
employed as desired. As will be described below, combustion of fuel
source 20 involves a surface effect and thus different shapes
provide different combustion characteristics. For example, a
generally conical shape has a large surface area and provides
relatively large amounts of heat, but bums correspondingly quicker
than shapes with relatively smaller exposed surface areas which
provide relatively less heat but burn slower and accordingly longer
for the same volume of material.
[0039] In one embodiment, the porous carrier of body 24 comprises
cellulose fibres. Specifically, body 24 comprises paper pulp which
has been formed into the desired shape and dried. It has been found
that the selection of the paper pulp influences the combustion
properties of fuel source 20. In particular, paper pulp of
relatively course fibres results in a fast and hot combustion
relative to that obtained from fuel source 20 when paper pulp of
relatively finer fibres is employed. Other suitable porous
materials include cloth, ground coal or charcoal. It is believed
that finer paper fibres provide a slower burn because the porous
carrier is more dense and less permeable to the vapours so the
vapours travel more -slowly through the body 24 to the combustion
surface 26.
[0040] It has also been determined that the porous carrier need not
be combustible. Specifically, other porous materials such as ground
pumice, sand and granular ceramic materials have been employed with
favourable results.
[0041] When a combustible porous carrier is used there is added
energy which is given off in the combustion of the product since
the carrier is combusted. After combustion of a combustible fuel
source having a combustible porous carrier, the remaining ash is
lightweight and easily disposed. On the other hand, the
non-combustible carrier is able to facilitate combustion of the
fuel but it itself is not combusted and therefore there is no
additional energy added.
[0042] While not completely understood, it is presently believed
that two factors generally influence the performance of the porous
carrier in combustible fuel sources in accordance with the present
invention. These two factors are (i) the ability of vaporized fuel
and oxygen to move through the porous carrier; and (ii) the ability
of the porous carrier to transfer heat from the combustion surface
26 into body 24 to vaporize the solid fuel. In addition, selection
of the porous carrier will affect the ash remaining after the fuel
source has combusted. For example, use of a combustible material as
a porous carrier will result in little waste materials (ash) and a
second combustion stage while use of non-combustible materials will
result in more waste material and no second combustion stage, as
described below.
[0043] Although it has not been conclusively determined, it is
believed that the combustible fuel source has a very efficient and
effective combustion as a result of the mechanism of action
described below. In particular, the initial combustion on the
surface of the porous carrier carries heat inwards towards the
centre of the combustible fuel source where the solid fuel is
liquefied (if the fuel is not in liquid form), vaporized and
transported to the surface of the porous carrier where it is
combusted. The process of liquefying, vaporizing and transporting
the vaporized fuel to the surface is termed osmosis. It is believed
that this osmosis occurs simultaneously while oxygen is drawn into
the porous carrier and then into the vaporized solid fuel and as
such the oxygen is then carried with the vapour to the surface of
the carrier to be combusted.
[0044] As the surface of the porous carrier is carbonized by the
increasing heat from the surface combustion, the situation
described above generally becomes more efficient. It is believed
that the increased efficiency is due to the increasing carbonised
surface which contains no solid fuel to impede the osmosis
occurring, allowing an increasing blend of oxygen and vaporized
fuel. When the solid fuel nears exhaustion, the centre of the
porous carrier achieves a high temperature and begins to cause the
porous carrier to "coal". As surface combustion of the vaporized
fuel expires, it is believed that there is a cooler area within the
porous carrier between the coal centre and the carbonised surface
which will smolder for a short time. It has also been observed at
this stage that there appears to be a-, release of a white vapour
of water. As the coal centre takes over the combustion of the
remaining material of the porous carrier, if it is a combustible
porous carrier, the carbonised carrier is able to realize a
complete combustion initiated from the centre of the carrier or the
coal centre.
[0045] Based on this theory of the mechanism of action of the
combustible fuel source of the present invention, the combustible
fuel source is believed to be combusted in two stages. First, there
is the osmosis of the solid fuel wherein the heat from the
combustion travels towards the-centre of the body vaporizing the
fuel which then moves to the surface where it is combusted while
oxygen is simultaneously drawn into the vaporized fuel and then to
the combustion surface where it also is consumed in the combustion.
Second, if the porous carrier is combustible, the porous carrier
will begin to combust from the centre of the body outwards. During
both the first and second stage, the combustible fuel source
generally remains intact and the only notable change from an
external visual examination is the shrinkage of the carrier.
However, if the combustible fuel source is handled it will
disintegrate revealing a very fine ash similar to the waste
material achieved by a "kiln" disposition of similar material.
[0046] It is believed that the ability of oxygen to permeate the
carrier and then be combusted on the surface with the vaporized
fuel is one of the reasons for the very efficient and effective
combustion of the combustible fuel source.
[0047] Furthermore, because the combustion process uses oxygen very
effectively, the combustion can be stopped almost instantly by the
elimination of the oxygen during the first stage of combustion. If
it is desirable to stop combustion in the second stage of the burn,
it is necessary to restrict the oxygen for a more extended period
of time. Although surface combustion expires immediately, the coal
effect continues to maintain high heat and when using a combustion
chamber the fuel must cool before oxygen is re-introduced or the
combustion may resume on the surface of the fuel. This aspect of
the efficient use of oxygen also allows for added safety when using
the fuel. For example, a chimney fire can be subdued quickly by
restricting oxygen to the fuel within the combustion chamber, the
resulting burst of vapour will generally suffocate the flames in
the chimney.
[0048] The solid fuel of body 24 preferably comprises a wax, such
as paraffin wax or beeswax, although other waxes and wax-like
substances such as animal or vegetable fats or shortening may also
be employed, if desired. In combustion, portions of the solid fuel
are first liquefied and then vaporized for combustion. As will be
apparent, the porous carrier serves to hold liquefied fuel and to
allow the vaporized fuel to move through the carrier to the
combustion surface 26
[0049] While waxes or the like are presently preferred for
convenience, cost and environmental considerations, it is presently
believed that the only required criteria for the solid fuel is that
it can be vaporized by the heat present within body 24 when fuel
source 20 is being combusted and that its vapours can move through
the porous carrier to the combustion surface.
[0050] The manufacture of fuel source 20 of FIG. 1A has been
performed in the following manner. The porous carrier is formed
from paper which is soaked in water and coarsely macerated to
obtain paper pulp which is then pressed into a generally conical
shape and dried. The dried, formed porous carrier is then emersed
into liquid paraffin wax or beeswax. The carrier absorbs the
liquefied wax until it is saturated and then the porous carrier is
removed from the liquefied wax and set aside to allow the wax to
solidify on the porous carrier to obtain body 24.
[0051] When solidified, a small bore can be formed in top of body
24 and wick 28 inserted into the bore and bonded in place with a
drop of liquid wax. It should be noted that, as mentioned above,
wick 28 is optional and when provided is only employed to initiate
combustion of fuel source 20. Thus, wick 28 need not penetrate body
24 to any great extent and a penetration of a half inch or less has
been found to be satisfactory. When wick 28 has been placed,
another small bore can be formed into the top of body 24, adjacent
wick 28, to receive safety match 29. As also mentioned above,
safety match 29 is also optional and need not be included. It will
also be apparent to those of skill in the art that the present
invention is not limited to the use of safety matches and that
these are merely preferred for safety reasons and that other
ignition devices can be employed if desired.
[0052] Ignition of fuel source 20 is easily accomplished by
igniting wick 28, if present, or otherwise heating a portion of
body 24 and igniting the resulting vaporized solid fuel on the
combustion surface 26. When first lit, combustion occurs only in
the area adjacent the point of ignition. However, as the solid fuel
adjacent the combustion area is heated, vaporized and combusted,
combustion spreads to substantially the entire exposed combustion
surface 26 of body 24, namely, all of the surface except the base
which is effectively smothered by the support surface 27 on which
it rests. The base of the body 24 when in contact with the support
surface 27 does not achieve surface combustion but generally is
effectively consumed by the coal, second stage combustion, if the
porous carrier is combustible.
[0053] It should be noted that combustion of fuel source 20 appears
to be largely a surface effect and it has been noted in tests that
solid fuel which has been liquefied but not vaporized and which has
leeched out of body 24 and onto the support surface 27 does not
tend to ignite.
[0054] Fuel source 20 has been tested using various porous
carriers. Tests were conducted using combustible porous carriers
with coarse paper and fine paper. In one test the relatively course
paper employed in egg crates was used as the porous carrier and
this has resulted in a relatively hot and quick combustion. The
course paper used in egg crates is essentially any over-processed
wood fibre or short fibre like Krofta Fines, which are expelled
during the manufacturing process of wood fibres to achieve fluff
pulp. Fluff pulp is used in environmentally friendly diapers and
feminine napkins. Because there is a portion of the wood fibre
which becomes to short through breakage in manufacturing to be
utilized in the machinery used to manufacture fluff pulp, it is
dropped from the process as waste.
[0055] In another test, finer paper, newsprint, was used as the
porous carrier. Newsprint is a finer paper because the wood strand
is long and is still considered to be a quality material. The finer
paper resulted in a relatively less hot but longer burning
combustion. In both cases, it should be noted that the combustion
of fuel source 20 appeared to be particularly efficient, with
little, if any, soot being produced.
[0056] As best understood, in the present invention the porous
carrier apparently transports the solid fuel which has been
vaporized from within body 24 to the combustion surface 26 of body
24 wherein combustion is occurring. It is presently believed that
the relative coarseness of the porous carrier regulates the speed
with which this transport occurs and thus is one of the limiting
factors in the combustion process. It is also believed that the
porous carrier serves to assist heat transfer from the combustion
surface 26 into body 24 to promote vaporization of the solid fuel
and that the porous carrier allows for air to be drawn into body 24
below the combustion surface 26 to facilitate clean and complete
combustion.
[0057] As mentioned above, it is not necessary that the porous
carrier be itself combustible. For example, in another test,
combustible fuel source 20 has been manufactured with crushed
pumice as the porous carrier. In this embodiment, the crushed
pumice is placed into an inverted conical form as in FIG. 1A and
liquefied wax is poured into the form. When the wax has set, wick
28 and safety match 29 can be inserted if desired, as before.
[0058] Although it is not necessary that the product be conical,
the conical shape has a number of positive implications. First, the
shape allows for maximum stability as a freestanding form.
[0059] Second, the conical shape also allows for a more efficient
combustion at the maximum surface area while having the
aforementioned stability. Referring to FIG. 1B, the tendency is for
the osmosis to occur straight up and combust at the top of the
porous carrier of the inverted cone 30 and over the somewhat
horizontal surface area 32. Thus, if the combustible fuel source is
in the shape of a cylinder 34 as opposed to an inverted cone 30, as
illustrated in FIG. 1B, it would achieve a slower combustion since
the combustion surface area 35 would be much less.
[0060] Third, the conical shape speeds the spread of ignition over
the entire exposed surface of the unit as the narrow top of the
cone warms quickly fueling more heat to quickly heat the wider body
near the bottom of the cone.
[0061] Fourth, the more efficient shape allows less vapour to
escape before complete combustion can occur. When the sides of the
carrier are straight up as in the cylindrical combustible fuel
source 34, there are bursts of vaporized fuel which escape outside
the area of combustion but with the conical shape 30 the entire
exposed horizontal surface area 32 is involved in combustion so
that more of the vapour is utilized in the combustion. This effect
has been observed for wood fibre carriers and pumice carriers.
[0062] In tests, this embodiment of combustible fuel source 20 of
FIG. 1A incorporating a pumice porous carrier was found to burn
particularly hot and relatively quickly and it is believed that
this is due to the relatively large amount of heat transferred into
body 24 by the pumice from the combustion surface 26 , thus
promoting the rapid vaporization of the solid fuel. It is
contemplated that finer control of the combustion characteristics
will be possible by crushing the pumice, or the like, to different
particle sizes to achieve more or less porosity in the porous
carrier.
[0063] Another property of combustible fuel source 20 is that the
porous carrier substantially retains its shape and cohesiveness
throughout substantially the entire combustion period of
combustible fuel source 20. This is believed to be due to the
vaporized solid fuel which moves through the porous carrier to the
combustion surface 26, the vapours apparently serving to assist the
porous carrier in retaining its structure until the solid fuel is
exhausted. The porous carrier is aided in retaining its shape by
the carbon ash produced during combustion of the solid fuel. This
occurs at the surface of the carrier and builds towards the centre
of the carrier while osmosis is progressing outwardly from the
interior of the carrier. Accordingly, it is believed that, for a
short time, both stages of combustion are occurring. As the carbon
builds at the surface, the carbon molecules continue to effectively
bond the carrier's particles together. This simplifies clean up and
disposal of the spent fuel source 20.
[0064] The embodiment of the present invention shown in FIG. 1A is
presently preferred for use as a fire starter by hikers, campers
and the like and it is believed will start a campfire of wood even
if the wood is wet. For example, as discussed below with reference
to FIGS. 2 and 3, the present invention can be used in candles and
the like.
[0065] FIGS. 2 and 3 show another embodiment of the present
invention which is useful as a candle, torch or the like. Fuel
source 40 is generally cylindrical and, in a similar fashion to
fuel source 20 described above, can include an initiation means,
such as wick 44, and an ignition means, such as safety match
48.
[0066] As shown in FIGS. 2 and 3, fuel source 40 includes a
cylindrical body 52 which comprises a porous carrier and a solid
fuel and also preferably includes an outer sheath 56 formed of a
less porous carrier and/or a denser solid fuel. Sheath 56 has been
found to encourage the combustion of fuel source 40 at the upper
end of the cylinder and to inhibit the spread of combustion of fuel
source 40 from the upper end to the side walls of the cylinder by
providing a relatively impermeable barrier to vaporized solid
fuel.
[0067] In one embodiment of fuel source 40 of FIGS. 2 and 3, body
52 is formed in the same manner as that described above for fuel
source 20 illustrated in FIG. 1A, with the pulp of relatively
coarse paper fibres being formed into a cylindrical shape, rather
than a conical shape, and liquid wax being subsequently impregnated
into the dried carrier and allowed to solidify. Sheath 56 is then
formed from paper, such as newsprint, which is rolled relatively
tightly about body 52 and then dipped briefly into liquid wax. When
the wax of sheath 52 has solidified, a bore is formed in the upper
end of fuel source 40 and wick 44 can be inserted and/or a bore is
formed in the upper end of fuel source 40 and a safety match 48 can
be inserted.
[0068] In tests, body 52 has been formed of relatively coarse paper
fibres from paper egg crates and impregnated with beeswax and
sheath 56 has been formed of rolled newsprint which is then
impregnated with paraffin wax. This combination has been found to
provide a relatively hot flame which is well contained by the
paraffin wax in sheath 56. Other combinations have also been
successfully tried, including body 52 being formed from rolled
newsprint and impregnated with beeswax or paraffin wax and sheath
52 constructed as before.
[0069] It should be noted that, as was the case with fuel source
20, wick 44 is only provided, if at all, to simplify the initiation
of combustion of fuel source 40. Thus it is not required that wick
44 extend along body 52 to any extent beyond that desired to
achieve the desired initiation of combustion and a wick of a half
inch or less will generally be sufficient. However, if it is
desired to enhance the ease with which fuel source 40 may be
re-lit, wick 44 can extend along the majority of body 52 and can be
used to relight fuel source 40. Wick 44 is only necessary if the
combustible fuel source is used as a flame source as in a candle.
The wick 44 may be a cotton fibre wick or any other appropriate
wick.
[0070] In a similar fashion, safety match 48 is not required and is
only provided if desired. If safety match 48 is not provided, any
suitable ignition means may be employed.
[0071] Also, as mentioned above, the cohesiveness of the porous
carrier in fuel source 40 is augmented by the solid fuel vapours
which move through the porous carrier and thus fuel source 40
typically does not drop ash or other waste while combustion is
occurring.
[0072] FIG. 4 illustrates another embodiment of the present
invention wherein a stove 100 employs a fuel source in accordance
with the present invention. Stove 100 comprises an outer shell 104
which, in a presently preferred embodiment of the invention, is an
aluminium or steel food or beverage can which has been recycled. As
shown in FIG. 4, the top has been removed from shell 104 and a
series of ventilation holes 108 have been placed around the upper
edge of shell 104. A fuel source 112 in accordance with the present
invention is placed within shell 104 and a bore is formed in the
upper surface of fuel source 112 and a wick 116 inserted
therein.
[0073] The shell 104 provides a support surface on which cooking
utensils and pots may be placed and also permits the combustible
fuel source 112 to contain a greater than 100% saturation of solid
fuel in the porous carrier to increase the energy life of the
product.
[0074] As with other embodiments of the present invention, fuel
source 112 comprises a porous carrier and a solid fuel. Several
varieties of porous carrier have been successfully tested to date,
including the above-mentioned relatively coarse paper fibres from
paper egg crates which have been soaked and macerated into a pulp
which is shaped, pressed and dried. This carrier was then emersed
in liquefied paraffin wax until it is impregnated with wax. Stove
100 with such a fuel source 112 has been found to provide
sufficient heat to boil a pot of water resting on the upper edge of
stove 100 in a reasonably quick manner. It has also been determined
that, once the combustion process is fully established in fuel
source 112, stove 100 is substantially wind proof or resistant to
being extinguished by wind currents and as such it is difficult to
extinguish by any means other than smothering stove 100.
[0075] Another embodiment which was tested for use with stove 100
was a porous carrier formed from tightly rolled corrugated
cardboard which was placed in the stove with the channels formed by
the corrugations of the cardboard being oriented vertically.
Liquefied paraffin wax was then poured into the stove 100 until the
porous core would not accept more wax. This embodiment of stove 100
has been found to provide a hot and relatively large flame, the
combustion process apparently being augmented by vaporized wax
which travels relatively quickly and easily along the
above-mentioned channels. As with the other embodiments of stove
100, this embodiment can be difficult to extinguish other than by
smothering as it is substantially wind proof.
[0076] Other embodiments of the combustible fuel source 112 have
also been tested with favourable results, including fuel sources
with porous carriers comprising rolled newsprint, crushed pumice,
leaves, needles, bark, Any plant and animal fibre, hair, fur,
ground bone, grass, cloth, leather, chaff from grain farming and
processing, hay, straw, dust, lint, coal powder and steel wool.
Solid fuels which have been tested have comprising beeswax, all
waxes including paraffin and petroleum waxes, all fats and oils
from all sources including canola, soya, lard, vegetable or animal
plus petroleum oils and greases. It is not necessary to use wax to
blend and solidify the oils but it is preferred to allow for
cleaner handling of the materials.
[0077] Generally, the preference is to use a 50% blend of wax with
the secondary solid fuel chosen. Moreover, it is preferred to use
wax in outdoor products intended to be carried in clothing prior to
use.
[0078] As with the other embodiments of the present invention, wick
116 is not required and other suitable means of initiating
combustion can be employed as will occur to those of skill in the
art. Or in the alternative, the combustible fuel source may simply
be ignited by holding the surface close to an open flame.
[0079] In another embodiment of the present invention, shown in
FIG. 5, fuel source 200 is configured into a block configuration
for use in a wood or coal-fired stove or furnace. Other
configurations could also be used such as a slab, log or brick-like
configuration. Fuel source 200 comprises a porous carrier and a
solid fuel, as before. Representative examples of suitable porous
carriers include paper fibres formed and dried as described above,
wrapped cloth, powered coal and/or non-combustible materials such
as crushed or ground pumice, sand or the like. The solid fuel used
in fuel source 200 can comprise paraffin wax, beeswax, or animal or
vegetable derived waxes, shortenings or the like.
[0080] It is contemplated that in such general heating
applications, it may be desirable to limit the area of the
combustion surface to reduce the combustion rate. In such cases,
fuel source 200 can first be placed in a shield, such as a metal
pan (not shown), which closely matches the outside dimensions of
fuel source 200 and which serves to limit combustion surface to the
upper surface 202 of fuel source 200 and to inhibit combustion from
occurring on the sides. To inhibit combustion on the sides of the
combustible fuel source 200 it is desirable to place the shield in
close proximity to the combustible fuel source 200.
[0081] For example, it has been found that if the shield is placed
one half inch from the sides of fuel source 200 then combustion of
the side of the fuel source 200 is substantially prevented. It is
not necessary to put the shield in contact with the sides of fuel
source 200.
[0082] In a test, a fifteen inch by twelve inch by four inch fuel
source 200 comprising a porous carrier formed from tightly wound
bristle board (fine cardboard) impregnated with paraffin wax and
placed in a shield, as described above, was combusted in a wood
burning furnace. Fuel source 200 was found to burn in the furnace
for approximately twenty-four hours and to provide the equivalent
amount of heat as a medium sized wood fire. In this test, the
combustion of the wax appeared to be sufficiently complete that no
substantial amount of harmful chimney deposits were visually
detected.
[0083] It is also contemplated that fuel source 200 is formed of a
non-combustible porous carrier, such as pumice, in which case the
solid fuel may be replenished as desired. For example, if a slab or
brick like carrier is employed, additional solid fuel can be
liquefied and introduced to the lower surface of the porous
carrier. Alternatively, solid fuel can be introduced adjacent to
the porous carrier and liquefied by waste heat from the combustion.
In either-case, this liquefied solid fuel is drawn into the porous
carrier under osmosis-like action and is heated therein, vaporized
and combusted. It is contemplated that this introduction of
additional solid fuel can be accomplished on an ongoing basis, if
desired, by any suitable means as would occur to those of skill in
the art. Alternatively, the porous carrier can be recovered, when
fuel source 200 is spent, and re-impregnated with solid fuel as
desired.
[0084] FIG. 6 shows another embodiment of the present invention
wherein an improved match 300 includes a fuel source 304 in
accordance with the present invention. In this embodiment, fuel
source 304 comprises a porous carrier and solid fuel, as before,
which has been bonded to a carrier stick 308. Carrier stick 308 can
be formed of combustible materials such a wood or paper like a
conventional match, or can be formed of incombustible materials
such as metal of glass if desired. A conventional match-type
ignition composition 312 is located at the tip of fuel source 304
such that, when appropriately struck, composition 312 ignites
initiating combustion of fuel source 304. It is contemplated that,
in some circumstances, it may be desirable to include a wick (not
shown) extending from fuel source 304 into composition 312 to
assist in the initiation of combustion of fuel source 304. As match
300 combusts fuel source 304, rather than carrier stick 308 as in a
conventional match, it is contemplated that match 300 will provide
a longer burn time and/or a greater heat supply and, like other
embodiments of the present invention, this embodiment can be
difficult to extinguish other than by smothering.
[0085] Further, match 300 is presently believed to be an effective
method of initiating combustion in fuel sources in accordance with
the present invention wherein a wick is not provided. The
substantial heat developed by match 300 and its relatively long
burn time are advantageous for this purpose.
[0086] FIG. 7 is an illustration of a cooking pot 400 which has a
layer of combustible fuel source 404 adhered to the bottom thereof.
When the layer of combustible fuel source 404 is appropriately
ignited using ignition means the combustible fuel source 404 burns
heating the pot 400 and thereby cooking whatever is contained
within the pot. The length of cooking required will determine the
thickness of the layer of the combustible fuel source.
[0087] FIG. 8 illustrates a wood pellet combustible fuel source
500. Wood pellets can be used a fuel enhancer. In a preferred
embodiment, the wood pellet is a blend of powdered bark and a
powdered blend of wood/paper pulp and fat product. The powdered
blend is heat compressed with the powdered bark which acts as a
bonding agent. (See Example 4)
[0088] All of the above embodiments exemplified in the Figures may
also contain waste materials or recovery blends. A recovery blend
is any material which would be potentially toxic if eaten,
potentially toxic to the environment and/or are considered waste
materials. For example, a clean fibre such as recycled non-toxic
paper that has only been exposed to vegetable dyes is a natural
blend not a recovery blend. Recovery blends include any material
which may not be safe. In the case of cloth fibre, this material
would not be considered a recovery blend if natural plant fibre was
processed into the carrier and there were no toxic dyes in its
composition. On the other hand, coloured or chemically treated
cloth fibres may be recovered efficiently by the process but could
not be considered non-toxic prior to combustion and therefore are a
recovery blend.
[0089] The recovery blends may be incorporated into the porous
carrier or the solid fuel. The general rule is that any material
that can be blended with the oil or liquid wax and will pass
thought the surface of the porous carrier is introduced into the
solid fuel saturation process and the others are introduced into
make up of the porous carrier.
[0090] Recovery blends that are incorporated into the combustible
fuel source achieve a more complete and efficient combustion.
[0091] The waste material can be processed into a powder and then
blended with the wood/paper pulp. The blend is then pressed into
the preselected shape to form the porous carrier, as discussed
above.
[0092] Alternatively, the waste material can be blended with
powdered fibre material, termed flash powder, and then using dry
heat compression the porous carrier can be formed to achieve the
desired shape. (See Example 4) The flash powder is generally
obtained from the waste created in the manufacturing process of a
combustible fuel source of the present invention. In particular,
the waste created when a fuel block or other preselected shape has
been cut to size.
[0093] In a particular embodiment of the invention, the flash
powder could be introduced to a waste material such as an oil spill
and when lit, the flash powder together with the oil will combust.
This may be done on the water and the flash powder will not absorb
the water, but will immediately absorb the oil. Once the oil has
been absorbed, the oil laden flash powder will continue to remain
buoyant and can easily be removed from the water for transport to a
remote location and combusted there or can be combusted on the
surface of the water and the material remains after the burn is
solid and wax-like and is easily removed form the water's surface
and continues to remain buoyant. The emissions from the combustion
are minimized due to the efficient combustion characteristics of
the flash powder.
[0094] In a further alternative, the waste material could form the
porous carrier by itself without a further fibre carrier. In this
latter process, the waste material would be powdered and pressed
into the-appropriate shape.
[0095] Waste materials which have been employed include railway
"ties", telephone poles, creosote, powdered coal, calcium oxalate
solids, krofta fines, bark, wood/paper and ink waste stream
material from recycled paper industry. In addition waste sludge
from waste water treatment plants may also be appropriate material
to include in the porous carrier.
[0096] Waste materials which are not detrimental to the environment
but are often placed in household waste, including garden waste
which may be incorporated into the porous carrier, including
leaves, pine needles, grass clippings and natural cloth fibres. In
addition certain, natural wastes created in industrial processing,
such as fish processing plants which produce fish fat as waste, or
slaughter houses which produce animal fat as waste, could be
incorporated into the combustible fuel source of the invention.
[0097] It has also been observed that when the combustible fuel
source of the present invention is combusted insects are repelled
from an area around said combustion. It is believed that the vapour
expelled during combustion of the combustible fuel source of the
present invention contains as aspect of biological material which
interferes with the ability of the insect to locate a food source
and as a result the insect relocates to a remote area away from the
combustion site. In particular, this has been observed with
mosquitoes and blackflies. It has been further observed that the
mosquitoes and blackflies will not return to the combustion site
for several days.
[0098] The following examples are further illustrations of
particular embodiments of the combustible fuel source of the
invention or processes for producing such embodiments.
[0099] Example 1: Combustible Fuel Source comprising a Porous
Carrier from Wood Fibre
[0100] When wood fibre is pulped for purposes of paper production,
the wood fibre is broken down to different degrees. The most
desirable situation to make paper resulting from the pulping
procedures are long strand wood fibres. The long strands are dense
and less porous than short strands and when integrated during paper
production the long strands cling to each other producing a quality
paper having strength, durability and slight water resistance. The
more the wood strands are processed, the more broken they become
resulting in shorter, more porous wood strands. The shorter wood
strands are less durable and quite absorbent. The resulting
implications are that the less desirable over-processed wood fibre
is not a viable material for paper production, as each processing
of the wood fibre leaves the strand shorter and eventually negates
any value for its use in paper. This short strand material is very
absorbent and will not readily combust on its own but provides a
suitable porous carrier when combined with a solid fuel of the
present invention.
[0101] The more processed the wood fibre is the more absorbent the
fibre becomes and the more absorbent the fibre becomes the greater
the amount of fuel which will be retained in the porous carrier.
This will result in a combustible fuel source which will produce
more energy on combustion.
[0102] On the other hand, the less refmed, longer strands of fibre
will absorb and retain less solid fuel but there will be greater
area between the strands to allow for rapid heating of the carrier
and a less restricted combustion process of the solid fuel
resulting in a quick, high heat, but a longer porous carrier life
due to the density of the individual strands. Essentially, the
opposite is true for shorter more absorbent strands, wherein the
combustible fuel source comprised of shorter strands will retain
more fuel but the area between the strands is less. As a result,
the porous carrier comprised of short strands will have a slower
and longer first stage combustion process then the porous carrier
comprised of longer strands which will have a longer second stage
combustion.
[0103] The short strand fibre when employed in a combustible fuel
source of the invention in a preselected shape having a thickness
greater than 5" begins to affect the efficiency of combustion of
the solid fuel in open air combustion. The short strand fibre
porous carrier having a thickness greater than 5" is a tight fibre
porous carrier which as it is carbonised to this thickness the
combustion is decreasing with concomitant decreasing energy. As a
result, less heat from the combustion is reaching the solid fuel
and it begins to restrict the osmosis of the solid fuel while
interfering with the efficient delivery of oxygen to the solid fuel
being vaporized within the carrier. In particular, there is a
greater area of cool down between the coal centre where the fuel
vaporizes and the surface combustion and as a result, the period of
time where vapour is expelled is extended. Accordingly, this short
strand product is not as effective for high intense combustions. On
the other hand, when this same product is disposed within a
suitable combustion chamber, the reflective nature of the heat
within the chamber effectively negates this concern.
[0104] Whether a short strand or long strand wood fibre is
incorporated into the porous carrier, either can be incorporated
using a wet compression method. The wet compression method, as
described above for FIG. 1A, encompasses soaking the wood fibre in
water and compressing the wood fibre into the desired shape and
then letting the wood fibre dry.
[0105] Example 2: Combustible Fuel Source comprising Wood Fibre
Fluff using a Steam Process
[0106] Dry wood/paper pulp can be ground or finely shredded to wood
fibre fluff. The resulting wood fibre fluff can b compressed to the
desired shape and then steam can be forced into the compressed
fluff form. The steam causes the wood fibres to bind together and
in this manner the carrier form is achieved. The advantage of this
process is a greatly reduced drying time is required to form the
carrier prior to saturation with the chosen solid fuel. It is
understood that a similar method is employed in some processes for
making particular types of fibre containers, including egg
cartons.
[0107] Example 3: Combustible Fuel Source comprising a Porous
Carrier obtained from a Sheet Layering Process
[0108] The porous carrier may also be formed by taking thin sheets
of porous wood fibre, such as balsa wood, or sheets of paper or
cardboard and layering these sheets to the desired thickness and
then using any method desired to apply even pressure. This pressure
need only be great enough to secure continuous contact between each
layer of fibre sheets. The porous carrier may then be introduced to
the liquefied fuel until the fibre is completely saturated with the
fuel. The resulting carrier would then be removed from the fuel and
the fuel would be allowed to solidify, if it was to be a solid
fuel, before, the chosen method of compression would be
removed.
[0109] Example 4: Fuel Pellets and Dry Heat Compression
[0110] Dry heat compression can be used to bond two or more
different materials using a powdered combustible fuel source of the
present invention termed flash powder. The flash powder acts as a
bonding agent. For example, dry powdered tree bark blended with
flash powder to create a high energy recovery blend fuel
pellet.
[0111] The flash powder is generally obtained from the waste
created in the manufacturing process of a combustible fuel source
of the present invention. In particular, the waste created when a
fuel block or other preselected shape has been cut to size. This
flash powder is then blended with the desired amount of powdered
bark. This bark/flash powder blend is then compressed into a heated
metal or stone form, at temperatures generally from 200 to 400
degrees Fahrenheit, which form represents the desired shape and
sized of the finished fuel product. Very quickly the fuel
components in the flash powder liquefy and while liquefied and
under pressure, quickly penetrate the bark powder. The form or
pellet is then expelled from the heated form and cooled to solidify
the material into a solid unit such as a pellet.
[0112] The dry heat compression is the most desirable method of
manufacturing fuel pellets, which are approximately 1-2 cm in
thickness and 1 and 1/2 cm in length. It should be noted that
pellets may be manufactured from other materials other than bark,
including calcium oxalate solids.
[0113] The above mentioned methods of production may also be
combined. One could use flash powder, dry wood/paper fibre fluff
and dry heat compression to achieve the desired form. In another
process, steam heat compression could be used to create a form
using a blend of wood/paper fibre fluff and powdered bark. In
another process, layered sheets of paper or porous wood fibre could
be compressed using pressure and steam and then allowing this
material to dry while pressure is continued. Once dried it is
saturated with the chosen fuel source. These are alternative
process in addition to the wet fibre compression method early
described.
[0114] Any of these methods of manufacturing may be employed as
long as the density of the carrier and the thickness of the
finished product can be achieved as required for the specific
product to provide the appropriate combustion characteristics of
the fuel source of this invention.
[0115] Example 5: Combustible Fuel Source incorporating Coal as a
Recovery Blend
[0116] When recovery blends such as powdered coal are used, the
coal realized a more complete and efficient combustion by this
union. There are two methods by which this recovery is done. First,
the powdered coal is blended with the porous carrier and then
continues through to the manufacturing process, through compression
to acquire shape, then curing, then fuel saturation.
[0117] Second, another procedure for recovery of coal is to take a
briquetted of the powdered coal and cover this with a jacket of the
porous carrier. The unit is then dried and subsequently saturated
with fuel.
[0118] The powdered coal is combusted much more efficiently when
incorporated into a combustible fuel source of the invention. Much
of the air borne emissions expelled from the burning material
occurs when an-incomplete combustion is allowing combustible
materials to be expelled into the air. for example, there is
inefficient smoldering of the charcoal for upwards of an hour which
can occur with barbequing with coal/charcoal briquettes and which
causes the release of undesirable combustion by-products into the
air.
[0119] Not only does the combustion achieve efficient combustion on
the surface of the charcoal, but the jacket remains intact as
carbon on the surface and effectively filters minute particles of
the coal that otherwise would become air borne. As the surface is
heating these particles are thereby combusted. In addition, if
barbequing with these products, any fat dripping onto the fuel from
the food is dispensed thought the carbonised jacket and combusted
as well. This minimizes "flare-ups".
[0120] The powdered charcoal formed into a combustible fuel source
of the invention would act as part of the porous carrier. However,
a unit of coal would not be considered itself to be a porous
carrier.
[0121] The above-described embodiments of the invention are
intended to be examples of the present invention and alterations
and modifications may be effected thereto, by those of skill in the
art, without departing from the scope of the invention which is
defined solely by the claims appended hereto.
* * * * *