U.S. patent application number 13/121363 was filed with the patent office on 2011-09-15 for heat-resistant fuel-activating substance.
This patent application is currently assigned to FIRE UP LTD.. Invention is credited to Masahiro Ito, Seitaro Takahashi.
Application Number | 20110219673 13/121363 |
Document ID | / |
Family ID | 42059436 |
Filed Date | 2011-09-15 |
United States Patent
Application |
20110219673 |
Kind Code |
A1 |
Takahashi; Seitaro ; et
al. |
September 15, 2011 |
HEAT-RESISTANT FUEL-ACTIVATING SUBSTANCE
Abstract
A fuel-activating substance comprising a fuel-activating
material and having heat resistance imparted thereto. This
fuel-activating substance can hence be applied or attached even to
parts to be used under such temperature conditions that use with
organic resin binders has been impossible, whereby the effect of
saving energy in combustion devices is further heightened. The
heat-resistant fuel-activating substance is characterized by being
obtained by melt-mixing 50-150 wt. % metallic thermal spray
material with 100 wt. % fuel-activating material of which the
spectral emissivity for electromagnetic waves with wavelengths in
the range of 3-20 .mu.m is 0.85 or more and making the mixture
capable of thermal spraying. Alternatively, 100 wt. % the
fuel-activating material and 50-150 wt. % metallic material having
a melting point of 420.degree. C. or lower may be formed into a
sheet through melting. Furthermore, a mixture of 100 wt. % the
fuel-activating material and 75-150 wt. % inorganic resin having a
heat resistance temperature exceeding 300.degree. C. may be formed
into a sheet or may be subjected to thermal spraying or applied in
a molten state.
Inventors: |
Takahashi; Seitaro; (Chiba,
JP) ; Ito; Masahiro; (Saitama, JP) |
Assignee: |
FIRE UP LTD.
Tokyo
JP
|
Family ID: |
42059436 |
Appl. No.: |
13/121363 |
Filed: |
September 15, 2009 |
PCT Filed: |
September 15, 2009 |
PCT NO: |
PCT/JP2009/004589 |
371 Date: |
April 27, 2011 |
Current U.S.
Class: |
44/314 |
Current CPC
Class: |
F23C 99/001 20130101;
F23C 99/00 20130101 |
Class at
Publication: |
44/314 |
International
Class: |
C10L 1/12 20060101
C10L001/12 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 29, 2008 |
JP |
2008-250379 |
Claims
1. A heat-resistant fuel-activating substance formed by melt-mixing
50 to 150% by weight of a metallic thermal spray material with 100%
by weight of a fuel-activating material having a spectral
emissivity of 0.85 or more for electromagnetic waves with
wavelengths in a range of 3 to 20 .mu.m, formed by blending
tourmaline, iron powder and carbon in proportions within a range of
30 to 44% by weight, 55 to 69% by weight, and 0.5 to 1.5% by
weight, respectively, thereby making the mixture capable of thermal
spraying.
2. A heat-resistant fuel-activating substance formed by melting 50
to 150% by weight of a metallic material having a melting point of
420.degree. C. or lower with 100% by weight of a fuel-activating
material having a spectral emissivity of 0.85 or more for
electromagnetic waves with wavelengths in a range of 3 to 20 .mu.m,
formed by blending tourmaline, iron powder and carbon in
proportions within a range of 30 to 44% by weight, 55 to 69% by
weight, and 0.5 to 1.5% by weight, respectively, to be formed into
a sheet.
3. A heat-resistant fuel-activating substance formed by mixing 75
to 150% by weight of an inorganic resin having a heat resistance
temperature exceeding 300.degree. C. with 100% by weight of a
fuel-activating material having a spectral emissivity of 0.85 or
more for electromagnetic waves with wavelengths in a range of 3 to
20 .mu.m, formed by blending tourmaline, iron powder and carbon in
proportions within a range of 30 to 44% by weight, 55 to 69% by
weight, and 0.5 to 1.5% by weight, respectively.
4. (canceled)
5. The heat-resistant fuel-activating substance according to claim
1 wherein 1.5% by weight or less of silicon is contained in 100% by
weight of the fuel-activating material.
6. The heat-resistant fuel-activating substance according to claim
2 wherein 1.5% by weight or less of silicon is contained in 100% by
weight of the fuel-activating material.
7. The heat-resistant fuel-activating substance according to claim
3 wherein 1.5% by weight or less of silicon is contained in 100% by
weight of the fuel-activating material.
Description
TECHNICAL FIELD
[0001] The present invention relates to a heat-resistant
fuel-activating substance suitable for use in combustion devices
such as boilers in which liquid fossil fuels such as heavy oil and
kerosene, gas fossil fuels such as LPG and natural gas, and solid
fossil fuels such as coal are used as fuels, and enhancing a
combustion-activating effect for the combustion therein.
BACKGROUND ART
[0002] Heretofore, various studies have been conducted for the
improvement of thermal efficiency at the time of combustion in
combustion devices such as boilers. For that purpose, for example,
like the invention described in Patent Document 1, there were some
proposals to improve burners.
[0003] The inventors of the present invention have proposed that
combustion efficiency at the time of combustion is improved by
activating methane-based molecules in a thermal decomposition
region using electromagnetic waves from a fuel-activating
substance. That is, methane-based molecules as a kind of active
chemical species generated by the thermal decomposition of the fuel
during the combustion have an absorption band that absorbs
electromagnetic waves with specific electromagnetic wavelengths,
specifically around 8 .mu.m (a range approximately 3 to 20 .mu.m).
Thus, radiation of the electromagnetic waves in the wavelength
region to the methane-based molecules in the thermal decomposition
region causes stronger vibration of the methane-based molecules as
a kind of active chemical species that are combustion precursors.
Thereby, frequency of collision between the methane-based molecules
and oxygen molecules in air is enhanced and combustion reactions
are accelerated, thus leading to a rise in flame temperature. As a
result, combustion efficiency comes closer to that of complete
combustion, thus realizing a reduction in the amount of the fuel
use. The present inventors have tried to develop a heat-resistant
fuel-activating substance that exhibits a high spectral emissivity
in such wavelengths.
[0004] For that purpose, focusing on tourmaline having an action of
radiating electromagnetic waves, tests of radiating electromagnetic
waves from tourmaline to methane-based molecules in a thermal
decomposition region were carried out. However, there was no
significant effect that enables an improvement in combustion
efficiency at the time of combustion.
[0005] Based on these findings, the present inventors disclosed an
invention described in Patent Document 2. This invention is
intended to obtain an energy saving effect by disposing a far
infrared ray generator, formed by mixing tourmaline, iron powder
and carbon, in a methane gas passageway located before a portion
where combustion occurs, thereby activating the fuel.
Patent Literature
[0006] Patent Document 1: JP 11-1707 A [0007] Patent Document 2: WO
2006/088084 A
SUMMARY OF INVENTION
[0008] After the above prior art, focusing particularly on a
spectral emissivity, the present inventors have intensively made an
improvement of a fuel-activating substance and found that a flame
temperature rise of 100 to 150.degree. C. is obtained by using a
fuel-activating material in which a spectral emissivity of
electromagnetic waves in the above wavelength region becomes 0.85
or more and radiating electromagnetic waves in the relevant
wavelength region to methane-based molecules in the thermal
decomposition region.
[0009] By the way, a conventional fuel-activating substance is
prepared by forming an activating material into a sheet using an
organic resin such as a urethane resin as a binder, or by forming
the activating material into a coating material to be affixed by
coating. Therefore, in case the fuel-activating substance is
affixed to a place at high temperature of 100.degree. C. or more in
a combustion device, the binder was sometimes carbonized with a
lapse of time, resulting in decrease of a spectral emissivity of
the electromagnetic waves from the fuel-activating substance.
[0010] Then, an object of the present invention is that an improved
fuel-activating material is used and also heat resistance is
imparted to a fuel-activating substance using this fuel-activating
material thereby making it possible to affix even under temperature
conditions where a conventional fuel-activating substance could not
be used, and thus an energy saving effect in various combustion
devices is further enhanced.
[0011] The heat-resistant fuel-activating substance according to a
first invention among the present invention is formed by
melt-mixing 50 to 150% by weight of a metallic thermal spray
material with 100% by weight of a fuel-activating material having a
spectral emissivity of 0.85 or more for electromagnetic waves with
wavelengths in a range of 3 to 20 .mu.m, thereby making the mixture
capable of thermal spraying.
[0012] Regarding "a spectral emissivity of 0.85 or more for
electromagnetic waves with wavelengths in a range of 3 to 20 .mu.m"
as stated herein, the relevant wavelength range is a wavelength
range of electromagnetic waves, that contributes the most to
activation of methane-based molecules in a thermal decomposition
region, and is a portion that is referred to as so-called "far
infrared rays." This spectral emissivity is a numerical value
assumed that an emissivity in the relevant wavelength range of a
blackbody is 1, and has significance as a numerical value enough to
radiate far infrared rays contributing to activation of
methane-based molecules. On this point, the same shall apply in the
respective inventions described hereinafter.
[0013] Herein, application of the heat-resistant fuel-activating
substance by thermal spraying enables application even to the place
having a complicated surface shape.
[0014] That is, the heat-resistant fuel-activating substance
according to the first invention is applicable to the site to be
applied in the combustion device at a temperature within a range
from about 100 to 400.degree. C. Herein, it is possible to use, as
the metallic thermal spray material, the group of materials having
comparatively low melting temperature, for example, copper,
aluminum and nickel. In particular, materials having a grain size
of 5 to 150 .mu.m are desirable.
[0015] When the content of the metallic thermal spray material is
less than 50% by weight in addition to 100% by weight of the
activating material, adhesion to the site to be applied becomes
worse. In contrast, when the content is more than 150% by weight,
the spectral emissivity decreases with the decrease of the
proportion of the fuel-activating material. Therefore, the content
is suitably from 50 to 150% by weight.
[0016] Such a metallic thermal spraying material is mixed with a
predetermined fuel-activating material and the obtained mixture is
filled in a commercially available thermal spraying apparatus, and
then the mixture is thermally sprayed onto a predetermined site to
be applied of a burner. A specific place to be thermally sprayed
includes a flange portion to which a burner is mounted a combustion
device, or the place behind the site where combustion flame occurs
inside a combustion device that accommodates the burner. It becomes
possible to form a heat-resistant fuel-activating substance as a
metal coating layer containing a fuel-activating material as a
component on the relevant place with a desired thickness. Moreover,
thermal spraying enables application even onto the place having a
surface shape with complicated unevenness where it is difficult to
affix with a sheet-like material.
[0017] The heat-resistant fuel-activating substance according to a
second invention among the present invention is formed by melting
50 to 150% by weight of a metallic material having a melting point
of 420.degree. C. or lower with 100% by weight of a fuel-activating
material having a spectral emissivity of 0.85 or more for
electromagnetic waves with wavelengths in a range of 3 to 20 .mu.m
to be formed into a sheet.
[0018] That is, the heat-resistant fuel-activating substance
according to the present second invention is applicable to the site
to be applied at a temperature within a range from about 100 to
300.degree. C. Herein, it is possible to use, as a metallic
material, metals having a comparatively low melting point, such as
lead and zinc.
[0019] When the content of the metallic material is less than 50%
by weight in addition to 100% by weight of the total amount of the
fuel-activating material, it becomes impossible to be formed into a
sheet. In contrast, when the content is more than 150% by weight,
the spectral emissivity decreases with the decrease of the
proportion of the fuel-activating material. Therefore, the content
is suitably from 50 to 150% by weight.
[0020] Such formation into a sheet enables affixing to a
predetermined site to be applied in the vicinity of a burner in a
combustion device, for example, a flange portion to which a burner
mounted, or the place behind the site where combustion flame occurs
inside a combustion device that accommodates the burner.
[0021] The heat-resistant fuel-activating substance according to
the third invention among the present invention is formed by mixing
75 to 150% by weight of an inorganic resin having a heat-resistant
temperature exceeding 300.degree. C. with 100% by weight of a
fuel-activating material having a spectral emissivity of 0.85 or
more for electromagnetic waves with wavelengths in a range of 3 to
20 .mu.m.
[0022] That is, the heat-resistant fuel-activating substance
according to the present third invention is applicable to the site
to be applied at a temperature within a range from about 100 to
300.degree. C. Herein, the inorganic resin having a heat-resistant
temperature exceeding 300.degree. C. does not refer to a resin that
is composed only of an organic resin, but refers to a resin in
which an inorganic material is partially or entirely used as the
component. It is possible to use, for example, a silicone resin, a
fluororesin, a water glass and the like, or a material having heat
resistance, such as a mixture that is optionally used after mixing
among these examples.
[0023] When the content of the inorganic resin is less than 75% by
weight in addition to 100% by weight of the total amount of the
fuel-activating material, it becomes impossible to be formed into a
sheet. In contrast, when the content is more than 150% by weight,
the spectral emissivity decreases with the decrease of the
proportion of the fuel-activating material. Therefore, the content
is suitably from 75 to 150% by weight. The fuel-activating material
may contain 0.5 to 1.5% by weight of silicon in 100% by weight of
the activating material.
[0024] The heat-resistant fuel-activating substance according to
the third invention can be formed into a sheet, and can also be
thermally sprayed onto the site to be applied in a molten state, or
sprayed or coated onto the site to be applied in a mixed state.
Formation into a sheet enables application as a sheet to a
predetermined site to be applied in the vicinity of a burner in a
combustion device, for example, a flange portion to which a burner
is mounted, or the place behind the site where combustion flame
occurs inside a combustion device that accommodates the burner. It
is also possible to conduct thermal spraying after melt-mixing, and
to conduct thermal spraying onto the position to form, on the
relevant position, a heat-resistant fuel-activating substance that
is an inorganic substance coating layer containing the
fuel-activating material as a component with a desired
thickness.
[0025] It is preferable that the fuel-activating materials in the
first invention to the third invention are formed by blending
tourmaline, iron powder and carbon in proportions within a range of
30 to 44% by weight, 55 to 69% by weight, and 0.5 to 1.5% by
weight, respectively.
[0026] Herein, it has already been confirmed by the test of the
present applicant that, when the proportion of at least one of the
respective components deviates from the range of the above blending
ratio, the spectral emissivity of the heat-resistant
fuel-activating substance is less than 0.85.
[0027] The heat-resistant fuel-activating substance may contain
1.5% by weight or less of silicon in 100% by weight of the
activating material. The significance of inclusion of this silicon
lies in that, in case the content of carbon had to be decreased,
silicon supplements lack of carbon, thus enabling the
heat-resistant fuel-activating substance to exhibit the spectral
emissivity of 0.85 or more.
[0028] Each of the heat-resistant fuel-activating substances shown
above can be used not only in a once-through boiler, a flame-tube
smoke-tube boiler and a water-tube boiler (including an industrial
boiler and a power station boiler that are equipped with two or
more burners), but also in burning appliances equipped with a
combustion device that uses combustion flame as a heat source, and
a combustion chamber, such as a kiln, a dryer, and a hot and
chilled water generator.
[0029] The "combustion chamber" as used herein refers to a portion
where a fuel blown from a burner quickly undergoes ignition and
combustion, and the generated combustible gas undergoes combustion
by satisfactory mixing and contacting with air.
[0030] In addition, the "burner" as used herein refers to a liquid
fuel burner, a gas fuel burner and a solid fuel burner, and is
specifically as follows.
[0031] The liquid fuel burner atomizes a fuel oil thereby
increasing the surface area and accelerates vaporization thereby
enabling satisfactory contact with air, thus completing a
combustion reaction, and specifically refers to a pressure
spraying-type burner, a steam (air) spraying-type burner, a
low-pressure air atomizing-type burner, a rotary burner, a gun type
burner and the like.
[0032] The gas fuel burner often utilizes a diffusion combustion
system, and specifically refers to a center-type burner, a
ring-type burner, a multispud burner and the like.
[0033] The solid fuel burner specifically refers to a burner of a
pulverized coal burner combustion system.
[0034] With the constitution of the present invention shown above,
it becomes possible to affix a heat-resistant fuel-activating
substance onto the place at comparatively high temperature, such as
inside of a combustion device, thus making it possible for the
electromagnetic waves radiated from this heat-resistant
fuel-activating substance to more directly act on combustion flame.
As a result, vibration of methane-based molecules as a kind of
active chemical species generated by thermal decomposition of a
fuel is activated and the combustion is accelerated, thus leading
to a rise in flame temperature and stable combustion flame. As a
result, it becomes possible to further decrease the amount of the
fuel use.
BRIEF DESCRIPTION OF DRAWINGS
[0035] FIG. 1 schematically shows a measuring device used to
examine a relationship between the spectral emissivity and the
flame temperature in a heat-resistant fuel-activating substance
according to the present invention.
[0036] FIG. 2 schematically shows a flame-tube smoke-tube boiler
affixed with a heat-resistant fuel-activating substance as a first
embodiment of the present invention.
[0037] FIG. 3 enlarges a burner portion in FIG. 2.
[0038] FIG. 4 schematically shows a once-through boiler affixed
with a heat-resistant fuel-activating substance as a second
embodiment of the present invention.
[0039] FIG. 5 enlarges a burner portion in FIG. 4.
[0040] FIG. 6 schematically shows a water-tube boiler affixed with
a heat-resistant fuel-activating substance as a third embodiment of
the present invention.
[0041] FIG. 7 enlarges a burner portion in FIG. 6.
DESCRIPTION OF EMBODIMENTS
(1) Verification of Blending Ratio of Fuel Activating Material
[0042] The following materials were used as a fuel-activating
material.
[0043] Tourmaline: Schorl tourmaline, 42 mesh (Adam Kozan Chuo
Kenkyusho Co., Ltd.).
[0044] Iron powder: RS-200A (POWDER TECH).
[0045] Carbon: activated carbon powder (C-AW; 12.011, SHOWA
CHEMICAL INDUSTRY CO., LTD.).
[0046] The above materials mixed in each blending ratio shown in
Table 1 described below was used as the fuel-activating material
and an inorganic silicone resin (ES-1002T, Shin-Etsu Chemical Co.,
Ltd.) as a binder was added thereto. The obtained mixture was
kneaded and was thereafter coated on a 2-mm thick aluminized steel
sheet so that a thickness of the obtained coating film became 0.6
mm to obtain samples. The obtained samples were subjected to the
measurement of the spectral emissivity.
[0047] The spectral emissivity was measured using a Fourier
transform infrared spectrophotometer of Shimadzu (IRPrestiga-21
(P/N206-72010), Shimadzu Corporation). Specifically, first, the
spectral emissivity was read as 1.0 by a blackbody furnace (at
300.degree. C.) and a measuring sample coated with a
pseudo-blackbody coating material (spectral emissivity: 0.94) was
then placed in a sample furnace. The spectral emissivity was set to
0.94 at a temperature in the sample furnace. Thereafter, each
sample was placed in the sample furnace under this condition and
the spectral emissivity was measured. The results were also shown
in Table 1 below.
TABLE-US-00001 TABLE 1 Sample Tourmaline Iron powder Carbon Total
Binder Spectral No. g % g % g % g g % emissivity 1 150 22.5% 508
76.0% 10 1.5% 668 668 100% 0.77 2 201 30.1% 458 68.6% 9 1.3% 668
668 100% 0.92 3 240 35.9% 420 62.9% 8 1.2% 668 668 100% 0.94 4 293
43.9% 368 55.1% 7 1.0% 668 668 100% 0.89 5 320 47.9% 344.5 51.6%
3.5 0.5% 668 668 100% 0.72 6 308 46.1% 350 52.4% 10 1.5% 668 668
100% 0.78 7 291.5 43.6% 367.5 55.0% 9 1.3% 668 668 100% 0.91 3 240
35.9% 420 62.9% 8 1.2% 668 668 100% 0.94 8 203 30.4% 460 68.9% 5
0.7% 668 668 100% 0.87 9 184 27.5% 480.5 71.9% 3.5 0.5% 668 668
100% 0.70 10 243 36.4% 424 63.5% 1 0.1% 668 668 100% 0.75 11 242.5
36.3% 422 63.2% 3.5 0.5% 668 668 100% 0.90 3 240 35.9% 420 62.9% 8
1.2% 668 668 100% 0.94 12 239 35.8% 419 62.7% 10 1.5% 668 668 100%
0.89 13 236 35.3% 417 62.4% 15 2.2% 668 668 100% 0.74 *Percentages
are % by weight based on the total.
[0048] As shown in the above results, the spectral emissivity of
Sample No. 3, in which the amount of tourmaline in the
fuel-activating material was 240 g (35.9% by weight), the amount of
iron powder was 420 g (62.9% by weight) and the amount of carbon
was 8 g (1.2% by weight), was 0.94, which was considered to be the
best mode. Using this sample as a center value, when the blending
ratio of tourmaline was 30% by weight or more and 44% by weight or
less (from Samples No. 2 and No. 4), the blending ratio of iron
powder was 55% by weight or more and 69% by weight or less (from
Samples No. 7 and No. 8) and the blending ratio of carbon was 0.5%
by weight or more and 1.5% by weight or less (from Samples No. 11
and No. 12), the spectral emissivity was found to become 0.85 or
more.
(2) Heat-Resistant Fuel-Activating Substance Formed by Metal
Spraying
[0049] Next, an appropriate weight ratio of a binder for metal
spraying was examined using the fuel-activating material of Sample
No. 3, which was considered as the best mode by the results of (1)
described above.
[0050] Metallizing 29029 as a binder (Eutectic of Japan Ltd.)
containing nickel and aluminum as main components in the weight
ratio shown in Table 2 below was melt-mixed with 100% by weight of
the fuel-activating material of Sample No. 3 described above, and
then the obtained melt mixture was thermally sprayed onto a 2-mm
thick aluminized steel sheet so that a thickness of the obtained
coating film became 0.6 mm, using Tero-Dizing System 2000 (Eutectic
of Japan Ltd.). With respect to the heat-resistant fuel-activating
substance formed by this thermal spraying, the spectral emissivity
was measured in the same manner as in (1) described above and also
adhesion to the thermal sprayed site was examined. The results were
as shown in Table 2 below.
TABLE-US-00002 TABLE 2 Sample Tourmaline Iron powder Carbon Total
Binder Spectral No. g % g % g % g g % emissivity 14 240 35.9% 420
62.9% 8 1.2% 668 300 45% -- 15 240 35.9% 420 62.9% 8 1.2% 668 334
50% 0.91 16 240 35.9% 420 62.9% 8 1.2% 668 668 100% 0.94 17 240
35.9% 420 62.9% 8 1.2% 668 1000 150% 0.90 18 240 35.9% 420 62.9% 8
1.2% 668 1150 172% 0.72 *Percentages are % by weight based on the
total.
[0051] As shown in the above results, the spectral emissivity of
Sample No. 16 in which the weight ratio of the binder compared to
100% by weight of the fuel-activating material is 100% by weight is
the highest value of 0.94 and, using this sample as a center value,
the spectral emissivity of Sample No. 15, in which the weight ratio
of the binder is 50% by weight, and that of Sample No. 17 in which
the weight ratio of the binder is 150% by weight were 0.85 or more.
To the contrary, in Sample No. 18 in which the weight ratio of the
binder is more than 150%, the spectral emissivity was less than
0.85. In Sample No. 14 in which the weight ratio of the binder is
less than 50% by weight, when the sample was rubbed by hands after
thermal spraying onto the steel sheet, the spray coating film was
easily peeled off. As a result, it has been found that the sample
showed poor adhesion performance as the heat-resistant
fuel-activating substance and was not suited for practical use.
[0052] As described above, in the case of forming a heat-resistant
fuel-activating substance by mixing with the binder for metal
spraying, an appropriate weight ratio of the binder compared to
100% by weight of the fuel-activating material is 50% by weight or
more and 150% by weight or less.
(3) Heat-Resistant Fuel-Activating Substance Formed as Metal
Sheet
[0053] Next, an appropriate weight ratio of a binder for forming
into a metal sheet was examined using the fuel-activating material
of Sample No. 3, which was considered as the best mode by the
results of (1) described above.
[0054] Lead as a binder in the weight ratio shown in Table 3 below
was blended with 100% by weight of the fuel-activating material of
Sample No. 3 described above, and then the obtained mixture was
melted at 350.degree. C. and formed into a 1-mm thick sheet. The
spectral emissivity of the sheet was measured in the same manner as
in (1) described above and also formability as the sheet was
examined. The results were as shown in Table 3 below.
TABLE-US-00003 TABLE 3 Sample Tourmaline Iron powder Carbon Total
Binder Spectral No. g % g % g % g g % emissivity 19 240 35.9% 420
62.9% 8 1.2% 668 300 45% -- 20 240 35.9% 420 62.9% 8 1.2% 668 334
50% 0.90 21 240 35.9% 420 62.9% 8 1.2% 668 668 100% 0.94 22 240
35.9% 420 62.9% 8 1.2% 668 1000 150% 0.88 23 240 35.9% 420 62.9% 8
1.2% 668 1150 172% 0.70 *Percentages are % by weight based on the
total.
[0055] As shown in the above results, the spectral emissivity of
Sample No. 21 in which the weight ratio of the binder compared to
100% by weight of the fuel-activating material is 100% by weight is
the highest value of 0.94 and, using this sample as a center value,
the spectral emissivity of Sample No. 20 in which the weight ratio
of the binder is 50% by weight, and that of Sample No. 22 in which
the weight ratio of the binder is 150% by weight were 0.85 or more.
To the contrary, in Sample No. 23 in which the weight ratio of the
binder is more than 150%, the spectral emissivity was less than
0.85. In Sample No. 19 in which the weight ratio of the binder is
less than 50% by weight, it was impossible to form into a sheet. As
a result, it has been found that the sample was not suited for
practical use as a heat-resistant fuel-activating substance.
[0056] As described above, in the case of forming a heat-resistant
fuel-activating substance by mixing with a metal binder and forming
the mixture into a sheet, an appropriate weight ratio of the binder
compared to 100% by weight of the fuel-activating material is 50%
by weight or more and 150% by weight or less.
(4) Heat-Resistant Fuel-Activating Substance Formed as Inorganic
Resin Sheet
[0057] Next, in the case of forming into a sheet using the
fuel-activating material of Sample No. 3, which was considered as
the best mode by the results of (1) described above, and using an
inorganic resin as a binder, a suitable weight ratio of the binder
was examined. The inorganic silicone resin used also in (1)
described above as an inorganic resin in the weight ratio shown in
Table 3 below was blended with 100% by weight of the
fuel-activating material of (1) described above, and then the
obtained mixture was kneaded and formed into a 1-mm thick sheet.
The spectral emissivity of the sheet was measured in the same
manner as in (1) described above and also formability as the sheet
was examined. The results were as shown in Table 4 below.
TABLE-US-00004 TABLE 4 Sample Tourmaline Iron powder Carbon Total
Binder Spectral No. g % g % g % g g % emissivity 24 240 35.9% 420
62.9% 8 1.2% 668 470 70% -- 25 240 35.9% 420 62.9% 8 1.2% 668 500
75% 0.91 26 240 35.9% 420 62.9% 8 1.2% 668 688 100% 0.94 27 240
35.9% 420 62.9% 8 1.2% 668 1000 150% 0.90 28 240 35.9% 420 62.9% 8
1.2% 668 1150 172% 0.71 *Percentages are % by weight based on the
total.
[0058] As shown in the above results, the spectral emissivity of
Sample No. 26 in which the weight ratio of the binder compared to
100% by weight of the fuel-activating material is 100% by weight is
the highest value of 0.94 and, using this sample as a center value,
the spectral emissivity of Sample No. 25 in which the weight ratio
of the binder is 75% by weight, and that of Sample No. 27 in which
the weight ratio of the binder is 150% by weight were 0.85 or more.
To the contrary, in Sample No. 28 in which the weight ratio of the
binder is more than 150%, the spectral emissivity was less than
0.85. In Sample No. 24 in which the weight ratio of the binder is
less than 75% by weight, it was impossible to form into a sheet. As
a result, it has been found that the sample was not suited for
practical use as a heat-resistant fuel-activating substance.
[0059] As described above, in the case of forming a heat-resistant
fuel-activating substance by mixing with an inorganic resin binder
and forming the mixture into a sheet, an appropriate weight ratio
of the binder compared to 100% by weight of the fuel-activating
material is 75% by weight or more and 150% by weight or less.
(5) Heat-Resistant Fuel-Activating Substance Formed as Inorganic
Resin Melt Thermal Spraying Sheet
[0060] Next, in the case of forming into a sheet by melting and
thermal spraying using the fuel-activating material as Sample No.
3, which was considered as the best mode by the results of (1)
described above, and using an inorganic resin as a binder, a
suitable weight ratio of the binder was examined. The inorganic
silicone resin used also in (1) described above as an inorganic
resin in the weight ratio shown in Table 3 below was blended with
100% by weight of the fuel-activating material of (1) described
above, and then the obtained mixture was melted and thermally
sprayed onto a 2-mm thick aluminized steel sheet so that the film
thickness became 1 mm. The spectral emissivity of the sheet was
measured in the same manner as in (1) described above and also
adhesion as the sheet was examined. The results were as shown in
Table 5 below.
TABLE-US-00005 TABLE 5 Sample Tourmaline Iron powder Carbon Total
Binder Spectral No. g % g % g % g g % emissivity 29 240 35.9% 420
62.9% 8 1.2% 668 470 70% -- 30 240 35.9% 420 62.9% 8 1.2% 668 500
75% 0.89 31 240 35.9% 420 62.9% 8 1.2% 668 668 100% 0.94 32 240
35.9% 420 62.9% 8 1.2% 668 1000 150% 0.87 33 240 35.9% 420 62.9% 8
1.2% 668 1150 172% 0.72 *Percentages are % by weight based on the
total.
[0061] As shown in the above results, the spectral emissivity of
Sample No. 31 in which the weight ratio of the binder compared to
100% by weight of the fuel-activating material is 100% by weight is
the highest value of 0.94 and, using this sample as a center value,
the spectral emissivity of Sample No. 30 in which the weight ratio
of the binder is 75% by weight, and that of Sample No. 32 in which
the weight ratio of the binder is 150% by weight were 0.85 or more.
To the contrary, in Sample No. 33 in which the weight ratio of the
binder is more than 150%, the spectral emissivity was less than
0.85. In Sample No. 29 in which the weight ratio of the binder is
less than 75% by weight, when the sample was rubbed by hands after
thermal spraying onto a steel sheet, the spray coating film was
easily peeled off. As a result, it has been found that the sample
showed poor adhesion performance as the heat-resistant
fuel-activating substance and was not suited for practical use.
[0062] As described above, in the case of forming a heat-resistant
fuel-activating substance by subjecting an inorganic resin binder
to melting and thermal spraying and forming the melt into a sheet,
an appropriate weight ratio of the binder compared to 100% by
weight of the fuel-activating material is 75% by weight or more and
150% by weight or less.
(6) Addition of Silicon
[0063] In the case of further adding silicon (silicon powder
(Si.14, SHOWA CHEMICAL INDUSTRY CO., LTD.)) to Sample No. 11 in
which the content of carbon was the lower limit of 0.5% by weight
in (1) described above, samples were made under the same conditions
as in (1) described above and then subjected to the measurement of
the spectral emissivity. The results were as shown in Table 6
below.
TABLE-US-00006 TABLE 6 Sample Tourmaline Iron powder Carbon Silicon
Total Binder Spectral No. g % g % g % g % g g % emissivity 11 242.5
36.3% 422 63.2% 3.5 0.5% 0 0.0% 668 668 100% 0.90 34 242.5 36.1%
422 62.9% 3.5 0.5% 3.3 0.5% 671.3 668 100% 0.92 35 242.5 35.9% 422
62.5% 3.5 0.5% 6.7 1.0% 674.7 668 99% 0.94 36 242.5 35.8% 422 62.2%
3.5 0.5% 10 1.5% 678 668 99% 0.91 37 242.5 35.7% 422 62.1% 3.5 0.5%
12 1.8% 680 668 98% 0.87 *Percentages are % by weight based on the
total.
[0064] As shown in the above results, the spectral emissivity of
Sample No. 11 in which silicon was not added was 0.90, whereas the
spectral emissivity was increased to 0.92 in Sample No. 34 in which
0.5% by weight of silicon was added. Furthermore, the spectral
emissivity was 0.94 in Sample No. 35 in which 1.0% by weight of
silicon was added and the spectral emissivity was 0.91 in Sample
No. 36 in which 1.5% by weight of silicon was added. In both
samples, the spectral emissivity was increased as compared with the
case where silicon was not added. However, the spectral emissivity
was rather decreased to 0.87 in Sample No. 37 in which the additive
percentage of silicon was more than 1.5% by weight (1.8% by
weight).
[0065] As described above, when the additive percentage of silicon
is 1.5% by weight or less, the significance of supplementing the
spectral emissivity was recognized in case the content of carbon is
comparatively low.
(7) Continuous Use of Heat-Resistant Fuel-Activating Substance
[0066] Next, an influence of continuous use on the spectral
emissivity under a high-temperature environment was examined.
[0067] A test piece obtained by coating an aluminum sheet measuring
100 mm.times.200 mm.times.2 mm in thickness with the heat-resistant
fuel-activating substance of Sample No. 31 in Table 5 described
above was placed on a horizontal steel plate supported by a prop,
and then heated by a gas ring to a temperature of 280 to
300.degree. C. for 7 hours per day from under the steel plate.
After completion of heating, the test piece was subjected to the
measurement of the spectral emissivity in the same manner as in (1)
described above. This operation was continued for 20 hours with
respect to the same test piece.
[0068] As a result, a change with time of the spectral emissivity
of the test piece was as shown in Table 7 below.
TABLE-US-00007 TABLE 7 Elapsed days Spectral emissivity 1 0.95 2
0.96 3 0.88 4 0.87 5 0.87 6 0.86 7 0.86 8 0.86 9 0.86 10 0.86 15
0.86 20 0.86
[0069] As described above, the spectral emissivity was kept at 0.85
or more over the entire test period.
[0070] Over the entire test period, blister, peeling or cracking
did not occur in the aluminum sheet coated with the heat-resistant
fuel-activating substance.
[0071] After the measurement of the spectral emissivity, a peeling
test was conducted in a state where the temperature was returned to
room temperature. Using a cutter, a lattice-shaped cut reaching an
aluminum layer was formed on a surface of a heat-resistant
fuel-activating substance at an interval of 5 mm, followed by
adhering an adhesive cellophane tape thereonto. The tape was peeled
off immediately was observed whether the peeled heat-resistant
fuel-activating substance adheres onto the tape or not. As a
result, over the entire test period, neither peeling of the
heat-resistant fuel-activating substance nor any burr was observed
at all.
[0072] Furthermore, an impact resistance test was conducted with
respect to tight adhesion. The same aluminum sheet coated with the
heat-resistant fuel-activating substance was placed on a floor and
a steel ball of 1 kg was dropped thereon three times from a height
of 1 m, and then it was observed whether peeling occurs or not. As
a result, any peeling of the heat-resistant fuel-activating
substance was not observed over the entire test period.
[0073] As shown in each observation described above, tight adhesion
of the heat-resistant fuel-activating substance onto a material to
be coated is extremely satisfactory.
[0074] It is additionally noted herein that the observation results
with respect to a change of the spectral emissivity and tight
adhesion with time were observed in common not only in mode of use
of spraying of the inorganic material of (1) described above, but
also in all of other modes of use.
(8) Relationship between Spectral Emissivity and Flame
Temperature
[0075] With respect to the presence or absence of affixing of the
heat-resistant fuel-activating material, and those having different
spectral emissivities among heat-resistant fuel-activating
substances, various tests were conducted and a change in flame
temperature was examined. Specifically, a measuring device 10 as
shown in FIG. 1 was used. That is, a burner 13 made of a stainless
steel tube having an inner diameter of 8.0 mm was connected to a
burner connection portion 12 equipped with an air hole 11, and also
a fuel pipe 14 protrudes from behind the burner connection portion
12 to halfway of the burner cylinder 13. A heat-resistant
fuel-activating substance 15 formed into a sheet using the
inorganic resin of (4) described above as a binder was affixed on
the portion that was an outer side face of this burner cylinder 13
and was also behind a tip of the fuel pipe 14.
[0076] This measuring apparatus 10 was disposed at room temperature
under an atmospheric pressure and a test was conducted. A flow rate
of fuel (city gas (13A, 88% of methane)) from the fuel pipe 14 was
adjusted to 73 cm/sec and a flow rate of air from the air hole 11
was adjusted to 27 cm/sec. Flame 16 occurring in the burner
cylinder 12 as a result of mixing them was videotaped by a
high-speed video camera (HPV-1, Shimadzu Corporation) and the
obtained video images were analyzed by a dichroic temperature
measurement/camera system (Thermera, Nobby Tech. Ltd.) thereby
measuring a flame temperature. The results are shown in Table 8
below.
TABLE-US-00008 TABLE 8 Affixing of heat- Flame Test resistant fuel-
Spectral temperature No. activating substance emissivity (K) 1 Not
affixed -- 2158 2 Affixed 0.70 2163 3 Affixed 0.75 2163 4 Affixed
0.80 2172 5 Affixed 0.85 2246 6 Affixed 0.87 2246 7 Affixed 0.90
2258 8 Affixed 0.92 2258 9 Affixed 0.94 2258
[0077] As described above, there was a tendency that the flame
temperature rose by affixing of the heat-resistant fuel-activating
substance, and also the flame temperature rose as the spectral
emissivity of the affixed heat-resistant fuel-activating substance
became higher. It has also been found that flame temperature rise
of 100 K was particularly observed in the test No. 1 in which the
heat-resistant fuel-activating substance was not affixed, and in
the tests Nos. 7 to 9 in which the spectral emissivity was 0.90 or
more.
[0078] As is also apparent from the test of the heat-resistant
fuel-activating substance other than (4) described above, the flame
temperature depended on the spectral emissivity.
Embodiments
(1) Test Results in Boiler
[0079] The above heat-resistant fuel-activating substance was
affixed in a specific boiler and the energy saving efficiency was
verified. Herein, the "energy saving efficiency" was defined as
follows.
[0080] First, a coefficient obtained by dividing the amount of fuel
(unit: liter in the case of liquid fuel, m.sup.3 in the case of gas
fuel) used during the test by the amount of water (unit: m.sup.3)
used to obtain steam before affixing of the heat-resistant
fuel-activating substance was defined as a "fuel use coefficient
before affixing" (E.sub.b).
[0081] On the other hand, a coefficient obtained by dividing the
amount of fuel used during the test by the amount of water used to
obtain steam after affixing of the heat-resistant fuel-activating
substance is similarly defined as a "fuel use coefficient after
affixing" (E.sub.a).
[0082] Then, an energy saving ratio (.eta.) is defined by the
following equation:
.eta.=(Eb-Ea)/Eb.times.100.
[0083] That is, a ratio (%) of a decrease in amount before and
after affixing of the heat-resistant fuel-activating substance of
the amount of fuel required to convert 1 cubic meter of water into
steam to the amount of fuel required before affixing was the energy
saving ratio (.eta.).
[0084] This was verified by various kinds of boilers below.
(1-1) First Embodiment
[0085] As the first embodiment, verification was conducted using a
flame-tube smoke-tube boiler as a specific boiler. The fuel used in
this flame-tube smoke-tube boiler (KMS-16A, IHI PACKAGED BOILER
CO., LTD.) was A-heavy oil, the burner used was a gun type burner,
the boiler capacity was 8,000 kg/h, and the control method was a
proportional control method. FIG. 2 is a schematic view of the
flame-tube smoke-tube boiler 20, and FIG. 3 enlarges a gun type
burner portion thereof. A combustion device 22 was attached to one
end (left end in FIG. 2) of a combustion chamber 28 in a boiler
body 21, and a combustion cone 23 enabled a cone maximum diameter
portion 24 having the maximum outer diameter to open toward inside
the boiler body 21 (rightward in FIG. 2, upward in FIG. 3), and
emitted flame from the tip of gun type burner 25 located in almost
the shaft center to a center direction of a combustion chamber 28.
A flange 26 that fixed the gun type burner 25 was provided at the
rear end of the combustion device 22. Each kind of heat-resistant
fuel-activating substances 15 in Table 9 below was affixed onto the
inner side face of the flange 26, whose area 27 was 100% of a
projected area of the cone maximum diameter portion 24 to the
flange 26 (cf. FIG. 3), and the fuel use coefficient before and
after affixing was calculated and then the energy saving ratio was
calculated therefrom. The results were shown in Table 9 below.
Regarding the spectral emissivity in the heat-resistant
fuel-activating substance, the weight ratio of each binder was
appropriately adjusted so as to become each numerical value shown
in the table below.
TABLE-US-00009 TABLE 9 Method of affixing Fuel use coefficient
Energy heat-resistant fuel- Spectral Before After saving rate
activating substance emissivity affixing affixing (%) Metal
spraying 0.90 72.46 68.86 4.97 Metal sheet 0.88 72.40 68.89 4.85
Inorganic resin sheet 0.94 72.30 68.46 5.31 Inorganic resin 0.92
72.35 68.62 5.16 thermal spray
[0086] As described above, even in each of the affixing methods, if
the spectral emissivity was 0.85 or more, a decrease of at least
4.85% or more of the fuel use coefficient before affixing was
observed. In particular, even if the heat-resistant fuel-activating
substance was different, there was a tendency that the energy
saving rate also increased with the increase of the spectral
emissivity of the heat-resistant fuel-activating substance. This is
assumed that the flame temperature may increase with the increase
of the spectral emissivity (cf. item (8) in "BEST MODE FOR CARRYING
OUT THE INVENTION").
(1-2) Second Embodiment
[0087] As the second embodiment, verification was conducted using a
once-through boiler as a specific boiler. The fuel used in this
once-through boiler (STE2001GLM, Nippon Thermoener Co., Ltd.) was
LPG, the burner used was a gun type burner, the boiler capacity was
1,667 kg/h, and the control method was a 3-position control method.
FIG. 4 is a schematic view of the once-through boiler 30, and FIG.
5 enlarges a gun type burner portion thereof. A combustion device
32 was attached to one end (upper end in FIG. 4) of a combustion
chamber 38 in a boiler body 31, and a combustion cone 33 enabled a
cone maximum diameter portion 34 having the maximum outer diameter
to open toward inside the boiler body 31 (downward in FIG. 4 and
FIG. 5), and emitted flame from the tip of gun type burner 35
located in almost the shaft center to a center direction of a
combustion chamber 38. A flange 36 that fixed the gun type burner
35 was provided at the rear end of the combustion device 32. Each
kind of heat-resistant fuel-activating substances 15 in Table 10
below was affixed onto the inner side face of the flange 36, whose
area 37 was 100% of a projected area of the cone maximum diameter
portion to the flange 36, and the fuel use coefficient before and
after affixing was calculated and then the energy saving ratio was
calculated therefrom. The results were shown in Table 10 below. The
heat-resistant fuel-activating substances used herein were
respectively the same as those used in the first embodiment.
TABLE-US-00010 TABLE 10 Method of affixing Fuel use coefficient
Energy heat-resistant fuel- Spectral Before After saving rate
activating substance emissivity affixing affixing (%) Metal
spraying 0.90 27.14 25.80 4.94 Metal sheet 0.88 27.12 25.83 4.76
Inorganic resin sheet 0.94 27.10 25.60 5.54 Inorganic resin 0.92
27.15 25.71 5.30 thermal spray
[0088] As described above, even in each of the affixing methods, if
the spectral emissivity was 0.85 or more, a decrease of at least
4.76% or more of the fuel use coefficient before affixing was
observed. In particular, even if the heat-resistant fuel-activating
substance was different, similar to the first embodiment described
above, there was a tendency that the energy saving rate also
increased with the increase of the spectral emissivity of the
heat-resistant fuel-activating substance.
(1-3) Third Embodiment
[0089] As the third embodiment, verification was conducted using a
water-tube boiler as a specific boiler. The fuel used in this
water-tube boiler (SCM-160, IHI Corporation) was C-heavy oil, the
burner used was a gun type burner, the boiler capacity was 16,000
kg/h, and the control method was a proportional control method.
FIG. 6 is a schematic view of the water-tube boiler 40, and FIG. 7
enlarges a gun type burner portion thereof. A combustion device 42
was attached to one end (lower end in FIG. 6) of a combustion
chamber 48 in a boiler body 41, and a combustion cone 43 enabled a
cone maximum diameter portion 44 having the maximum outer diameter
to open toward inside the boiler body 41 (upward in FIG. 6 and FIG.
7), and emitted flame from the tip of gun type burner 45 located in
almost the shaft center to a center direction of a combustion
chamber 48. A flange 46 that fixed the gun type burner 45 was
provided at the rear end of the combustion device 42. Each kind of
heat-resistant fuel-activating substances 15 in Table 11 below was
affixed onto the inner side face of the flange 46, whose area 47
was 100% of a projected area of the cone maximum diameter portion
44 to the flange 46, and the fuel use coefficient before and after
affixing was calculated and then the energy saving ratio was
calculated therefrom. The results were shown in Table 11 below. The
heat-resistant fuel-activating substances used herein were
respectively the same as those used in the first embodiment.
TABLE-US-00011 TABLE 11 Method of affixing Fuel use coefficient
Energy heat-resistant fuel- Spectral Before After saving rate
activating substance emissivity affixing affixing (%) Metal
spraying 0.90 70.50 68.31 3.11 Metal sheet 0.88 70.52 68.35 3.08
Inorganic resin sheet 0.94 70.38 67.89 3.54 Inorganic resin 0.92
70.42 68.05 3.37 thermal spray
[0090] As described above, even in each of the affixing methods, if
the spectral emissivity was 0.85 or more, a decrease of at least 3%
or more of the fuel use coefficient before affixing was observed.
In particular, even if the heat-resistant fuel-activating substance
was different, similar to the first and second embodiments
described above, there was a tendency that the energy saving rate
also increased with the increase of the spectral emissivity of the
heat-resistant fuel-activating substance.
(2) Others
[0091] It is additionally noted herein that almost the same effects
were obtained even in the case of using boilers other than the
above respective general-purpose boilers, industrial boilers and
using, in addition to the above fuels, biofuel, propane gas and the
like as fuels used in the boilers, regardless of the kind.
INDUSTRIAL APPLICABILITY
[0092] The present invention can be utilized not only in a
once-through boiler, a flame-tube smoke-tube boiler and a
water-tube boiler (including an industrial boiler and a power
station boiler that are equipped with two or more burners), but
also in burning appliances equipped with a combustion device, such
as a kiln and a dryer.
* * * * *