U.S. patent application number 12/937853 was filed with the patent office on 2011-02-10 for low-energy flame thrower arrangement and a related method.
Invention is credited to Arno Hahma, Timo Multamaki, Heiko Romu.
Application Number | 20110033805 12/937853 |
Document ID | / |
Family ID | 39385853 |
Filed Date | 2011-02-10 |
United States Patent
Application |
20110033805 |
Kind Code |
A1 |
Multamaki; Timo ; et
al. |
February 10, 2011 |
LOW-ENERGY FLAME THROWER ARRANGEMENT AND A RELATED METHOD
Abstract
A method for creating flames, wherein combustible powder
material is injected into a gas stream (120) and the dispersed
mixture of powder and gas is ignited and discharged through a
nozzle (124). An arrangement suitable for implementing the method
is also disclosed.
Inventors: |
Multamaki; Timo; (Aska,
FI) ; Romu; Heiko; (Turku, FI) ; Hahma;
Arno; (Aura, FI) |
Correspondence
Address: |
YOUNG & THOMPSON
209 Madison Street, Suite 500
Alexandria
VA
22314
US
|
Family ID: |
39385853 |
Appl. No.: |
12/937853 |
Filed: |
April 14, 2009 |
PCT Filed: |
April 14, 2009 |
PCT NO: |
PCT/FI2009/050276 |
371 Date: |
October 14, 2010 |
Current U.S.
Class: |
431/8 ;
431/91 |
Current CPC
Class: |
F41H 9/02 20130101; F42B
4/00 20130101; A63J 5/023 20130101 |
Class at
Publication: |
431/8 ;
431/91 |
International
Class: |
F41H 9/02 20060101
F41H009/02 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 14, 2008 |
FI |
20080283 |
Claims
1-15. (canceled)
16. A method for creating flames by a flame-thrower arrangement,
characterized in that combustible powder material is injected into
a gas stream (120) and the dispersed mixture of powder and gas is
discharged through a nozzle, ignited, and blown out of the
arrangement (124) so as to create a flame.
17. A method according to claim 16, wherein said gas stream is
divided into core and envelope components (122).
18. A method according to claim 16, wherein turbulence is formed in
the core component of said gas stream comprising core and envelope
components, wherein the gas flow in the envelope component is
optionally laminar.
19. A method according to claim 16, wherein said gas stream is
created by at least one element selected from the group consisting
of: pressurized gas, blower and chemical gas generator.
20. A method according to claim, 16 wherein said powder material
comprises at least one element selected from the group consisting
of: wood dust, potato flour, and wheat flour.
21. A method according to claim 16, wherein the powder material
further comprises additional particles or bodies for changing the
color of the flame, producing odour or creating a pyrotechnic
effect, such as an explosion or smoke.
22. A method according to claim 16, wherein predetermined liquid is
further injected into the gas stream for changing the color of the
flame, producing odour or creating a pyrotechnic effect, such as an
explosion or smoke.
23. A method according to claim 16, wherein said mixture is ignited
in the nozzle.
24. A method according to claim 16, wherein fuel-to-gas ratio in
said nozzle is at maximum about 20 kg/m.sup.3 and at minimum about
0.02 kg/m.sup.3.
25. An arrangement for creating flames, characterized in that the
arrangement comprises a means (102, 102b) for injecting combustible
powder material into a gas stream, a means for discharging the
dispersed mixture of powder and gas through a nozzle (103, 103b,
108, 200, 300), and a means for igniting (103b, 204) the mixture
blown out of the arrangement so as to create a flame.
26. An arrangement according to claim 25, wherein the arrangement
further comprises a means (304) for dividing said gas stream into
core and envelope components.
27. An arrangement according to claim 26, wherein the arrangement
comprises a means (305) for forming turbulence in said core
component of said gas stream.
28. An arrangement according to claim 25, wherein said means for
igniting (103b, 204) are integrated with the nozzle (103, 103b,
200, 300).
29. An arrangement according to claim 25, wherein it further
comprises a means for injecting liquid into the gas stream in order
to change the color of the flame, produce odour or create a
pyrotechnic effect, such as an explosion or smoke.
30. A flame-thrower for creating visual effects by flames,
characterized in that it comprises the arrangement of claim 25.
31. A method according to claim 17, wherein turbulence is formed in
the core component of said gas stream comprising core and envelope
components, wherein the gas flow in the envelope component is
optionally laminar.
Description
FIELD OF THE INVENTION
[0001] The invention relates to a method and arrangement for
producing special effects such as low-energy flames.
BACKGROUND
[0002] Pyrotechnic effects producing large flames have been
traditionally created by quickly burning large amounts of flammable
liquid or gas. For example, explosion-like special effects may be
achieved by dispersing a container filled with a flammable liquid
with a small explosive charge. As a result the liquid is dispersed
and ignited in the surrounding air, thereby creating a large
fireball. A large special effect may correspondingly require very
large amounts, e.g. tens or hundreds of liters of flammable
liquid.
[0003] Continuous large flames are typically generated by burning
large volumes of some suitable flammable gas, e.g. butane or
propane streaming out of a nozzle. By varying the flow rate of the
gas and the nozzle properties, flames of various sizes and shapes
can be created.
[0004] Burning large volumes of flammable high-energy fuels such as
gasoline or propane causes significant safety risks as lots of heat
is released in the combustion process. This significantly limits
the usability of such methods. For example, creating large flames
indoors is very challenging and in many cases impossible because of
the safety risks.
[0005] Some solutions have been developed for producing small flame
effects indoors, e.g. in theatres. These solutions are typically
based on pyrotechnic compounds or burning e.g. black or smokeless
gunpowder. These solutions are not completely risk-free as the
smoke may be toxic and/or the compounds may explode in an
uncontrollable manner. In addition, they require licenses and
clearances to be used legally and are hazardous in storage and
transport.
[0006] In prior art solutions using flammable liquids or gases, the
flame may be colored by e.g. adding color-donating salts into the
liquid or gas. The resulting mixtures may develop toxic gases. For
example, a green flame may be achieved by adding barium chloride
into the fuel, e.g. methanol. Additionally, some source of
chlorine, e.g. hydrochloric acid, may be needed to make the color
more vivid. Chlorinated materials may generate e.g. phosgene which
is toxic even in small amounts.
[0007] Some power plants, e.g. those burning coal, are arranged to
blow air into the middle of a fuel cloud comprising of coal dust.
As a result, the coal dust burns as quickly and efficiently as
possible releasing as much energy as possible.
[0008] Publication JP2001132910 discloses a flame generator for
achieving special effects. The generator consists of four nozzles
that are arranged around an ignition device.
[0009] Publication JP7052114 discloses a fireworks device that is
capable of spreading the desired fireworks effect into a large area
in a controllable manner. The publication discloses the use of saw
dust in a fireworks device.
[0010] Publication US2270443 discloses a method and device for
altering color of a flame using some suitable powdered material.
The flame in this disclosure is produced by burning some suitable
gas as is generally known in prior art.
[0011] Publication U.S. Pat. No. 6,953,401 discloses a device for
simulating a flame effect. The flame simulation is achieved by
creating a wall of fog onto which a suitable beam of light is
projected.
[0012] U.S. Pat. No. 5,756,920 discloses a flame cannon for
producing an explosion-like effect. The cannon includes a tank, a
valve, a nozzle and an igniter. The tank is coupled to a carbon
dioxide and a propane source.
[0013] Thus, numerous techniques for producing large flames e.g.
for special effect purposes are known in the art.
[0014] The objective of the present invention is to provide a
method and arrangement for producing large low-energy flames by
burning powdered material(s), such as a powder comprising fine
particles. Another objective is to improve the safety of special
effects with large flames. Yet another objective is to improve the
controllability of special effect flames.
SUMMARY OF THE INVENTION
[0015] The present invention discloses a method and arrangement for
producing a low-energy flame using powdered materials.
[0016] The method of the present invention is characterized in that
combustible powder, e.g. some suitable powdered material is
injected into a gas stream and the dispersed mixture of powder and
gas is discharged through a nozzle and ignited.
[0017] The gas stream may comprise a core and an envelope
component. The gas flow in the core component may be faster than
the flow speed of the envelope component. The gas flow in the core
component may advantageously be at least slightly turbulent.
Turbulence depends on the flow velocity. Especially when the flow
velocity is low, a guiding structure may be applied to adjust the
turbulence so as to maintain the flame stable and/or prevent it
from going out. The gas flow in the envelope component may
advantageously be laminar.
[0018] The nozzle may comprise at least one static or moving
structure that divides the gas flow into the core component and the
envelope component surrounding the core component.
[0019] The nozzle may comprise a component in which the diameter of
the nozzle may expand by 100%, 200%, 300% or 500% allowing the
diameter of the gas stream to expand while flowing through the
nozzle.
[0020] The nozzle may further comprise a cylindrical component.
[0021] The nozzle may be arranged to comprise or be attached to
some suitable means for igniting the mixture of gas and powder. The
means may include e.g. an ignition flame, electric spark or an
electric heating element. The amount of energy used by the ignition
means may be adjustable.
[0022] Preferably the utilized gas is relatively cold, e.g. below
the autoignition temperature of the used fuel, and contains enough
oxidant to burn a substantial portion of the powder and maintain
the flame.
[0023] The gas advantageously contains oxygen. Suitably, the gas
may be air.
[0024] The gas stream may be created using e.g. pressurized gas or
a blower. The velocity of the gas stream may be adjusted to be
suitable e.g. for the powdered material and/or nozzle used.
[0025] The nozzle may comprise a means for generating turbulence in
the gas stream. The turbulence may be advantageously generated such
that it occurs in the core component of the gas stream. Further
advantageously, creation of turbulence is avoided in the envelope
component of the gas stream.
[0026] The flow velocity of the gas stream at the nozzle exit may
be e.g. at least about 1, 10 or 20 m/s. At maximum, the flow rate
of the gas stream may be e.g. up to about 20, 50 or 100 m/s or
more. Preferably, the flow velocity may be between about 5 and 20
m/s.
[0027] The feed rate of powder material into the mixing chamber
and/or nozzle may be e.g. at least about 20 g/s/m.sup.3, 200
g/s/m.sup.3, 2 kg/s/m.sup.3 or 20 kg/s/m.sup.3 calculated to normal
pressure.
[0028] The powder may be any suitable combustible powder, e.g. wood
dust, potato flour, or wheat flour. It shall be noted that the heat
of combustion of such powders are substantially lower than of
conventional fuels. In general, any finely divided, combustible
organic or inorganic material may be applicable as a powdered
fuel.
[0029] The minimum particle size (diameter) of the powder may be
e.g. about 1, 5 or 10 micrometers. The maximum particle size of the
powder may be e.g. about 20, 100, 500 or 1000 micrometers.
[0030] In some embodiments, a bimodal powder comprising a finely
divided and coarse grained component may be used.
[0031] The powder may comprise additional particles or bodies
suitable for producing additional effect in the flame. The
additional effect may be e.g. a change of color of the flame or a
pyrotechnic effect, e.g. an explosion. Such additional effects may
also be achievable by injecting, e.g. via an applicable injector,
some suitable liquid into the gas stream. Examples of such
materials are granulate or pellets or the like comprising or
consisting of a pyrotechnic composition, which ignites later in the
flame creating e.g. small explosion-like effects along the length
of the flame. The added particles may comprise easily ignitable
metal powders creating bright sparks in the flame and enhancing the
visual effect. The liquid may be a combustible or noncombustible
liquid, which contains dissolved, color-enhancing materials
coloring the flame to red, green, blue, lilac, violet, yellow or
any other, desired color except black. The particles, bodies or
liquid added may also generate smoke in the desired colors and/or
they may produce any desired odour not normally obtained from
burning fuels.
[0032] The fuel-to-gas ratio (kilograms of fuel/cubic meters of air
calculated to normal pressure) in the nozzle may be at maximum
about 20 kg/m.sup.3, 10 kg/m.sup.3 or 5 kg/m.sup.3.
[0033] and at minimum 2 kg/m.sup.3, 1 kg/m.sup.31/g or 0.5
kg/m.sup.3, or even less, for example. The suitable ratio depends
e.g. on the powdered material used and its moisture content as well
as on the carrier gas used.
[0034] The components of the arrangement of the invention may be
dimensioned and/or the feed rate of fuel and/or flow rate of gas
may be adapted so as to produce a flame having a length of at least
about 2, 3 or 4 meters. Basically the flame may range from about
0.1 to over 10 meters.
[0035] The invention also concerns an arrangement that implements
the method disclosed herein.
[0036] As to the utility of the present invention, the inventors
have surprisingly observed that the method and apparatus disclosed
herein allow controlled, relatively slow burning of powdered
material that according to prior art would either burn explosively
or not ignite at all. Inventors believe that the flow of gas as
disclosed in various embodiments of the invention contribute
significantly to the phenomenon. The invention solves shortcomings
of the prior art for example by creating flames that emit
relatively low amount of heat since they burn at an unusually slow
rate for the material. The invention may be applied to produce
relatively large flames that can be safely used even by
inexperienced operators and indoors. As a further benefit, fuel,
which is not classified as hazardous material, may be used.
[0037] Some embodiments of the invention are described herein, and
further applications and adaptations of the invention will be
apparent to those of ordinary skill in the art.
BRIEF DESCRIPTION OF RELATED DRAWINGS
[0038] In the following, the invention is described in more detail
with reference to the accompanying drawings in which
[0039] FIG. 1a depicts an arrangement of an embodiment of the
present invention,
[0040] FIG. 1b is a combined block and flow diagram of an
embodiment of the present invention,
[0041] FIG. 1c is a flow diagram of an embodiment of the present
invention,
[0042] FIG. 2 depicts an exemplary nozzle of an embodiment of the
present invention,
[0043] FIG. 3 depicts an exemplary nozzle according to another
embodiment of the present invention,
[0044] FIG. 4a depicts a side view of an embodiment of the present
invention, and
[0045] FIG. 4b depicts a frontal view of the embodiment of FIG.
4.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0046] FIG. 1a illustrates a merely exemplary arrangement according
to an embodiment of the present invention. The arrangement
comprises a fuel silo/hopper 100 that is connected to an injector
102 through a connector 101. The connector 101 may comprise a means
105, such as a feeder, to control the flow rate of the fuel powder
(e.g. wood dust) from the fuel silo 100 to the injector 102. A gas
flow is provided by blowing gas (e.g. air) into the injector 102
through an air valve 104. In some embodiments, e.g. in those where
the gas stream is provided by a fan, the air valve 104 may be
optional. A dispersion of gas and fuel powder is lead from the
injector 102 to the nozzle 103 in which it is ignited by an
ignition means (see e.g. FIG. 2 and related text) while being blown
out of the arrangement to form a preferably low-energy flame.
Alternatively, an ignition means external to the nozzle 103 may be
applied. For example, the ignition means may be attached by a stand
to the outer surface of the nozzle or other element of the
arrangement and be aligned so as to enable igniting the dispersion
exiting the nozzle 103.
[0047] FIG. 1b illustrates a combined block and flow diagram of an
embodiment of the present invention. Broken arrows indicate gas
flow, a thin arrow indicates the flow of fuel powder, thick arrows
indicate the flow of gas/fuel dispersion, and a hollow arrow
indicates the emission a flame. Fuel storage 100b such as the
aforesaid silo is utilized for providing the fuel powder into a
feeder/mixer block 102b wherein it is mixed with the gas provided
thereto e.g. by a compressor or other feasible gas stream creation
element 104b and optionally an intermediate transport pipe 106.
Subsequently, the dispersion is conveyed to the nozzle/ignition
block 103b, optionally via another transport pipe 108. Control
logic and optional safety circuit(s) 110 may be applied in
controlling and monitoring the operation of various elements of the
arrangement as indicated in the figure by the connecting lines. The
logic 110 may include a microprocessor, a microcontroller, a
programmable logic chip, an ASIC, etc. in addition to various data
storage means such as a RAM/ROM memory chip. Power systems 112 may
supply power to one or more elements by a battery, for
instance.
[0048] FIG. 1c discloses a flow diagram of a basic embodiment of a
method in accordance with the present invention. Such method may be
executed by an arrangement according to the present invention, such
as the arrangement of FIG. 1a or 1b. At 120 the fuel powder is
mixed with gas as described hereinbefore. Then the obtained
dispersion is optionally adjusted as desired. For example, the
stream may be divided into core and envelope components, and
turbulence may be introduced thereto. At 124 the mixture is ignited
and discharged through the nozzle, the actual temporal order of
these actions being dependent on e.g. whether the ignition means is
integrated in the nozzle (i.e. substantially simultaneous ignition
and discharge) or implemented as a separate element (discharged
first). A skilled person will appreciate the fact that the
presented method may be supplemented with various additional phases
and operations in view of the teachings provided herein.
[0049] FIG. 2 illustrates a nozzle 200 (corresponding to e.g.
nozzle 103 of FIG. 1) of an embodiment of the present invention in
more detail. The nozzle 200 is attached to a connector 201 through
which the gas stream is flowing. In one embodiment, the length of
the nozzle is about 150 millimeters and the outer diameter is about
50 mm. The connector 201 has a length of about 30 mm and inner
diameter of about 15 mm. Inside the nozzle, there may be one or
more structures or other arrangements 202, 203 to divide the gas
stream into core and envelope components and optionally to cause
suitable turbulence in the core component of the stream before the
dispersed mixture is ignited using an ignition means 204.
[0050] FIG. 3 illustrates a nozzle 300 of another embodiment of the
present invention depicted in two side view projections. The nozzle
comprises a conical section 301 and a cylindrical section 302. A
structure assembled from perforated steel band (303-305) is
attached to the cylindrical section. The width of the perforated
steel band (e.g. "Patent Band") may be e.g. about 1-2 cm. The
structure comprises a connection means 303 that connects the
structure to the cylinder section 302. The guiding structure 304
divides the gas flow into core component and envelope component.
The structure 305 causes slight turbulence to the core component of
the gas stream consisting of mixture of gas and powder, e.g. wood
dust, potato flour or wheat flour in air.
[0051] Various features of the afore-explained embodiments relating
to nozzles 200, 300 may also be modified and/or combined by a
skilled person.
[0052] In the following, few test results of using an embodiment
described in FIGS. 1 and 2 are provided. A butane torch (100 g/h)
was used for igniting the mixture of fuel and air. A compressor
capable of compressing air to pressure of up to 6 bar and a 20
liter tank were used as the source of air. Surprisingly, positive
pressure of less than 1 bar gauge was needed in the tests. The
inventors thus became convinced that suitable gas stream may also
be achievable with a low-pressure blower, e.g. the one utilized in
a common household vacuum cleaner.
[0053] When operating the arrangement described in FIGS. 1 and 2
using wood dust as fuel and fuel-to-air ratio of about 6
kg/m.sup.3, the arrangement produced a horizontally oriented flame
of about 7 meters length.
[0054] In the tests, the flame was burning for about 7-8 seconds,
on average. Some test runs tried to maximize the burning time of
the flame on same amount of fuel. In these test runs, the burning
times were between about 10-12 seconds. At all times the flame died
when the fuel ran out. Hence, it is evident that unlimited fuel and
air supply would lead to an unlimited time of controlled burn.
[0055] When operating the arrangement using wood dust (moisture
content about 4.3%) and fuel-to-air ratio of about 3 kg/m.sup.3,
the arrangement produced a horizontally oriented flame of about 3.8
meters length.
[0056] When operating the arrangement using wheat flour (moisture
content about 10%) and fuel-to-air ratio of about 10 kg/m.sup.3,
the arrangement produced a horizontally oriented flame of about 3
meters length.
[0057] FIG. 4a depicts a side view of an embodiment of the present
invention. The arrangement comprises a fuel intake 400, a feeder
405, such as a rotary feeder, an air intake 404 comprising e.g. a
blower, a mixer 402, a nozzle 403, a feeder motor 405b, one or more
pressure sensors 410 and a sensor air pipe 412 related thereto for
precise control of the operational parameters (DATA refers to a
pressure signal). An ignition means may be integrated, optionally
removably, with the nozzle 403 (built-in, for example) or be
external thereto.
[0058] FIG. 4b depicts a frontal view of the same embodiment
wherein one possible implementation of a rotary feeder 405c is
shown in more detail (rotor shaft with vanes) on the left.
Advantageously the overall construction of the arrangement is
modular in a sense that various elements thereof are separable
parts including the feeder 405, the air intake 404, the mixer 402,
and/or the nozzle 403, for instance. Modularity enables changing
individual elements to better fit each potential use scenario or
upon a failure.
[0059] As shown in the above examples, the embodiments of the
present invention facilitate burning a powder comprising fine
particles in a controllable manner. As only a relatively low amount
of relatively low-energy fuel is needed to generate a large flame,
the amount of energy (heat) released by the combustion is quite
low. The controllability of the flame has been observed to be quite
easy e.g. by controlling the feed rate of gas (air) and/or fuel.
For example, changes in the fuel feed rate are practically
immediately observable in the flame. Another advantage of the
embodiments of the present invention is that, unlike the fuels of
prior art solutions, the fuel usable in the various embodiments of
the invention is safe to store, transport, handle and use.
Typically, no permissions and/or special skills or caution is
required when dealing with the fuel. Furthermore, the fuel usable
in the embodiments of the invention is typically not classified as
a hazardous material.
[0060] The scope of the invention can be found in the following
claims. Notwithstanding the various embodiments described
hereinbefore in detail, a person skilled in the art will understand
that different modifications may be introduced to the explicitly
disclosed solutions without diverging from the fulcrum of the
present invention as set forth in this text and defined by the
independent claims. For example, selected features of different
embodiments may be cleverly combined to come up with a new
embodiment with desired properties.
* * * * *