U.S. patent application number 13/702736 was filed with the patent office on 2013-04-11 for melting equipment.
This patent application is currently assigned to MITSUBISHI HEAVY INDUSTRIES ENVIRONMENTAL & CHEMICAL ENGINEERING CO., LTD.. The applicant listed for this patent is Takehiro Kitta, Yoshihisa Saito, Jun Sato, Toshimasa Shirai, Eri Yaegashi. Invention is credited to Takehiro Kitta, Yoshihisa Saito, Jun Sato, Toshimasa Shirai, Eri Yaegashi.
Application Number | 20130087084 13/702736 |
Document ID | / |
Family ID | 45098201 |
Filed Date | 2013-04-11 |
United States Patent
Application |
20130087084 |
Kind Code |
A1 |
Sato; Jun ; et al. |
April 11, 2013 |
MELTING EQUIPMENT
Abstract
The melting equipment has a melting furnace that combusts and
melts ash, a secondary combustion chamber disposed above the
melting furnace, a slag extraction chute that guides slag generated
in the melting furnace downward, a bypass channel (20) that
connects the slag extraction chute and the secondary combustion
chamber, an ejector (22) that is provided between the bypass
channel (20), has a contraction portion (23) at which the channel
cross sections are narrowed, and suctions the combustion exhaust
gas (G) into the bypass channel (20), and an adhesion-prevention
unit (31) (41) that prevent an incorporated substance that
incorporates into the combustion exhaust gas (G) from attaching to
the inner wall surface (21a) of the ejector (22).
Inventors: |
Sato; Jun; (Tokyo, JP)
; Kitta; Takehiro; (Tokyo, JP) ; Shirai;
Toshimasa; (Yokohama-shi, JP) ; Saito; Yoshihisa;
(Yokohama-shi, JP) ; Yaegashi; Eri; (Yokohama-shi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Sato; Jun
Kitta; Takehiro
Shirai; Toshimasa
Saito; Yoshihisa
Yaegashi; Eri |
Tokyo
Tokyo
Yokohama-shi
Yokohama-shi
Yokohama-shi |
|
JP
JP
JP
JP
JP |
|
|
Assignee: |
MITSUBISHI HEAVY INDUSTRIES
ENVIRONMENTAL & CHEMICAL ENGINEERING CO., LTD.
Yokohama-shi, Kanagawa
JP
|
Family ID: |
45098201 |
Appl. No.: |
13/702736 |
Filed: |
June 10, 2011 |
PCT Filed: |
June 10, 2011 |
PCT NO: |
PCT/JP2011/063364 |
371 Date: |
December 7, 2012 |
Current U.S.
Class: |
110/218 |
Current CPC
Class: |
F23C 2900/09002
20130101; F23G 2209/30 20130101; F23J 1/08 20130101; F23J 3/00
20130101; F23J 1/02 20130101; F23G 5/085 20130101; F04F 5/467
20130101; F04F 5/22 20130101; F23G 2202/104 20130101; Y02E 20/12
20130101; F23J 9/00 20130101; F23J 2219/70 20130101; F23L 17/16
20130101; F23G 2206/203 20130101; F23G 5/16 20130101 |
Class at
Publication: |
110/218 |
International
Class: |
F23J 1/02 20060101
F23J001/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 11, 2010 |
JP |
2010-134194 |
Claims
1. A melting equipment comprising: a melting furnace that combusts
and melts an ash; a secondary combustion chamber disposed above the
melting furnace; a slag extraction chute that guides a slag
generated in the melting furnace downward; a bypass channel that
connects the slag extraction chute and the secondary combustion
chamber; an ejector that is provided on the bypass channel, has a
contraction portion at which a channel cross section thereof is
narrowed, and suctions a combustion exhaust gas into the bypass
channel; and an adhesion-prevention unit that prevents an
incorporated substance that is incorporated in the combustion
exhaust gas from attaching to an inner wall surface of the
ejector.
2. The melting equipment according to claim 1, wherein the
adhesion-prevention unit has an adhered substance removal portion
that removes an adhered substance that is attached to the inner
wall surface of the ejector.
3. The melting equipment according to claim 2, wherein the adhered
substance removal portion supplies vibration to the inner wall
surface of the ejector.
4. The melting equipment according to claim 2, wherein the adhered
substance removal portion blows an air to the inner wall surface of
the ejector.
5. The melting equipment according to claim 2, wherein the adhered
substance removal portion performs mechanical washing on the inner
wall surface of the ejector.
6. The melting equipment according to claim 1, wherein the
adhesion-prevention unit has a swirling separation portion that is
provided at an upstream of the contraction portion, swirls the
introduced combustion exhaust gas so as to form a swirling flow,
and centrifugally separates an incorporated substance included in
the swirling flow.
7. The melting equipment according to claim 6, wherein the swirling
separation portion has a cooling system that cools the inner wall
along which the swirling flow of the combustion exhaust gas
flows.
8. The melting equipment according to claim 6, wherein a plurality
of the ejectors is provided in a row.
9. The melting equipment according to claim 1, wherein the
adhesion-prevention unit has an air film forming portion that forms
an air film along the inner wall surface of the ejector.
10. The melting equipment according to claim 1, wherein: the
adhesion-prevention unit includes a plurality of replaceable
branching channels that is provided at the bypass channel, and
branches on the upstream side and joins with the downstream side;
and each of the plurality of the branching channels has an
ejector.
11. The melting equipment according to claim 1, wherein: the
adhesion-prevention unit includes a liquid dispersion portion that
is provided upstream of the ejector, and disperses liquid in the
combustion exhaust gas so as to remove the incorporated substance
included in the combustion exhaust gas; and the driving air in the
ejector has a temperature that is equal to or higher than the
temperature at which the dispersed liquid gasifies.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a melting equipment.
[0002] Priority is claimed on Japanese Patent Application No.
2010-134194, filed on Jun. 11, 2010, the entire content of which is
incorporated herein by reference.
DESCRIPTION OF RELATED ART
[0003] As is well known, there is a gasification melting system as
a technique that can treat a wide range of wastes from municipal
waste to non-flammable waste, burned residues, sludge, landfilled
solid waste, and the like. The gasification melting system is
provided with: a gasification furnace that thermally decomposes and
thus gasifies waste; and a melting equipment that is arranged on
the downstream side of the gasification furnace and combusts the
thermally decomposed gas generated from the gasification furnace at
a high temperature so as to melt ash in the gas into molten
sludge.
[0004] The following Patent Document 1 discloses a gasification
melting system equipment provided with: a melting furnace that
combusts thermally decomposed gas and chars at a high temperature;
an exhaust equipment that exhausts slag generated from the melting
furnace; and a secondary combustion chamber that combusts the
combustion exhaust gas generated from the melting furnace a second
time. The gasification melting system equipment is provided with:
an ejector that suctions the combustion exhaust gas through a
combustion exhaust gas extraction pipe that is provided at the
bottom portion of a slag tap of the melting furnace; and a fan that
sends driving air to the ejector for suctioning the combustion
exhaust gas into the ejector. With the above configuration, the
high-temperature combustion exhaust gas is circulated so as to
maintain the slag tap at a high temperature, thereby continuously
suppressing solidification of slag and continuing favorable
circulation without lowering the temperature of the combustion
exhaust gas for circulation.
PRIOR ART DOCUMENT
[Patent Document]
[0005] [Patent Document 1] Japanese Unexamined Patent Application,
First Publication No. 2003-161411
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0006] However, in the related art, there was a problem in that the
circulation of the combustion exhaust gas becomes unstable because
salts having a low melting temperature and/or slag droplets and the
like that are accompanied by the combustion exhaust gas are
incorporated into the combustion exhaust gas, move along with the
combustion exhaust gas, and cause the incorporated substance to
attach to the inner wall surface of the ejector.
[0007] The present invention has been made in consideration of the
above circumstance, and an object thereof is to provide a melting
equipment that can stably circulate combustion exhaust gas by
suppressing clogging or narrowing a channel of the combustion
exhaust gas.
Means for Solving the Problem
[0008] In order to achieve the above object, the present invention
employs the following measures.
[0009] That is, according to a first aspect of the present
invention, a gasification melting furnace is provided with: a
melting furnace that combusts and melts ash; a secondary combustion
chamber disposed above the melting furnace; a slag extraction chute
that guides slag generated in the melting furnace downward; a
bypass channel that connects the slag extraction chute and the
secondary combustion chamber; an ejector that is provided on the
bypass channel, has a contraction portion at which a channel cross
section thereof is narrowed, and suctions the combustion exhaust
gas into the bypass channel; and an adhesion-prevention unit that
prevents an incorporated substance that is incorporated in the
combustion exhaust gas from attaching to the inner wall surface of
the ejector.
[0010] According to the above configuration, since the
adhesion-prevention unit is included, an incorporated substance of
dust or salts in the combustion exhaust gas is prevented from
attaching to the inner wall surface of the ejector. Thereby, the
combustion exhaust gas channel is not clogged or narrowed; and
therefore the combustion exhaust gas can be stably circulated.
[0011] In addition, the adhesion-prevention unit preferably has an
adhered substance removal portion that removes an adhered substance
that is attached to the inner wall surface of the ejector.
[0012] According to the above configuration, since the adhered
substance removal portion that removes the adhered substance that
is attached to the inner wall surface of the ejector is included,
the adhered substance can be removed even when the incorporated
substance included in the combustion exhaust gas is attached to the
inner wall surface of the ejector.
[0013] In addition, the adhered substance removal portion
preferably supplies vibration to the inner wall surface of the
ejector.
[0014] According to the above configuration, since the adhered
substance removal portion supplies vibration to the inner wall
surface of the ejector, the adhered substance on the inner wall
surface of the ejector can be removed without inhibiting the smooth
flow of the combustion exhaust gas or driving air of the
ejector.
[0015] In addition, the adhered substance removal portion
preferably blows air to the inner wall surface of the ejector.
[0016] According to the above configuration, since the adhered
substance removal portion blows air to the inner wall surface of
the ejector, it is possible to remove the adhered substance being
attached to the inner wall surface of the ejector using blown air,
and join the removed adhered substance into the flow of the
ejector. Thereby, the adhered substance can be blown toward the
downstream side more reliably, and efforts for maintenance, such as
cleaning, can be reduced.
[0017] In addition, the adhered substance removal portion
preferably performs mechanical washing on the inner wall surface of
the ejector.
[0018] According to the configuration, since the adhered substance
removal portion performs mechanical washing on the inner wall
surface of the ejector, the adhered substance on the inner wall
surface of the ejector can be directly removed.
[0019] In addition, the adhesion-prevention unit preferably has a
swirling separation portion that is provided upstream of the
contraction portion, swirls the introduced combustion exhaust gas
so as to form a swirling flow, and centrifugally separates any
incorporated substance included in the swirling flow.
[0020] According to the above configuration, since the swirling
separation portion that centrifugally separates the incorporated
substance included in the swirling flow is included upstream of the
contraction portion, an incorporated substance that reaches the
contraction portion can be reduced. Thereby, the adhered substance
that is attached to the inner wall surface of the ejector can be
reduced.
[0021] In addition, the swirling separation portion preferably has
a cooling system that cools the inner wall along which the swirling
flow of the combustion exhaust gas flows.
[0022] According to the above configuration, since the cooling
system that cools the inner wall along which the swirling flow of
the combustion exhaust gas flows is included, it is possible to
separate salts incorporated in the combustion exhaust gas and the
combustion exhaust gas by solidifying the volatilized salts that
are included in the combustion exhaust gas. Thereby, the adhered
substance that is attached to the inner wall surface of the ejector
can be further reduced.
[0023] In addition, a plurality of the ejectors is preferably
provided in a row.
[0024] According to the above configuration, since the plurality of
the ejectors is provided in a row, the combustion exhaust gas can
be favorably introduced to the bypass channel even when the
swirling separation portion having a great pressure loss is
provided at upstream of the contraction portion.
[0025] In addition, the adhesion-prevention unit preferably has an
air film forming portion that forms an air film along the inner
wall surface of the ejector.
[0026] According to the above configuration, since the air film
forming portion that forms an air film along the inner wall surface
of the ejector is included, the incorporated substance included in
the combustion exhaust gas does not easily reach the inner wall
surface of the ejector. Thereby, the incorporated substance that is
attached to the contraction portion can be reduced.
[0027] In addition, the adhesion-prevention unit preferably has a
plurality of replaceable branching channels that is provided at the
bypass channel, and branches on the upstream side and joins with
the downstream side, and each of the plurality of the branching
channels has an ejector.
[0028] According to the above configuration, since the bypass
channel has a plurality of the replaceable branching channels that
branches on the upstream side, and joins with the downstream side,
and the ejector is provided at each of the branching channels, it
is possible to circulate the combustion exhaust gas using one
branching channel and to clean the ejector in the other branching
channel. Therefore, it is possible to clean the ejector so as to
remove the adhered substance on the inner side surface of the
ejector while continuing the operation of the melting
equipment.
[0029] In addition, the adhesion-prevention unit preferably has a
liquid dispersion portion that is provided at upstream of the
ejector, and disperses liquid in the combustion exhaust gas so as
to remove the incorporated substance included in the combustion
exhaust gas, and the driving air in the ejector preferably has a
temperature that is equal to or higher than the temperature at
which the dispersed liquid gasifies.
[0030] According to the above configuration, since the
adhesion-prevention unit has the liquid dispersion portion, and the
driving air in the ejector has a temperature that is equal to or
higher than the temperature at which the dispersed liquid gasifies,
even when liquid mist is included in the combustion exhaust gas
through liquid dispersion, the liquid is gasified so as to suppress
the liquid being attached to the inner wall surfaces of the
ejectors and the wall surfaces of the bypass channel. Thereby,
trapping of the residual incorporated substance in the combustion
exhaust gas by the liquid attached to the inner wall surfaces of
the ejectors and the wall surfaces of the bypass channel is
suppressed; and therefore the combustion exhaust gas channel is
prevented from being clogged or narrowed, whereby the combustion
exhaust gas can be stably circulated.
Effects of the Invention
[0031] According to the melting equipment of the present invention,
it is possible to stably circulate combustion exhaust gas by
suppressing clogging or narrowing of the channel of combustion
exhaust gas.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 is a schematic view of a gasification melting system
S according to an embodiment of the present invention.
[0033] FIG. 2 is an enlarged view of the main parts of melting
equipment 1A according to a first embodiment of the present
invention.
[0034] FIG. 3 is an enlarged cross-sectional view of an ejector 21
according to the first embodiment of the present invention.
[0035] FIG. 4 is an enlarged cross-sectional view of an ejector 21A
according to a first modified example of the first embodiment of
the present invention.
[0036] FIG. 5 is an enlarged cross-sectional view of an ejector 21B
according to a second modified example of the first embodiment of
the present invention.
[0037] FIG. 6 is an enlarged view of the main parts of melting
equipment 1B according to a second embodiment of the present
invention.
[0038] FIG. 7 is a schematic configuration view of melting
equipment 1B1 according to a first modified example of the second
embodiment of the present invention.
[0039] FIG. 8 is an enlarged cross-sectional view of the main parts
of melting equipment 1B2 according to a second modified example of
the second embodiment of the present invention.
[0040] FIG. 9 is an enlarged cross-sectional view of the main parts
of melting equipment 1C according to a third embodiment of the
present invention.
[0041] FIG. 10 is a schematic configuration view showing an
adhesion-prevention unit 36A according to a modified example of the
third embodiment of the present invention.
[0042] FIG. 11 is a schematic configuration view showing melting
equipment 1D according to a fourth embodiment of the present
invention.
[0043] FIG. 12 is a schematic configuration view showing melting
equipment 1E according to a fifth embodiment of the present
invention.
EMBODIMENTS OF THE INVENTION
[0044] Hereinafter, embodiments of the present invention will be
described with reference to the accompanying drawings.
[0045] Firstly, a gasification melting system according to first to
fourth embodiments of the present invention will be schematically
described.
[0046] (Gasification Melting System)
[0047] FIG. 1 is a schematic view of a gasification melting system
S.
[0048] The gasification melting system S is provided with: a
fluidized-bed type gasification furnace 100 that thermally
decomposes and gasifies waste; a melting equipment 1A that is
provided on the downstream side of the fluidized-bed type
gasification furnace 100, and combusts thermally decomposed gas C
generated in the fluidized-bed type gasification furnace 100 at a
high temperature so as to make ash in the gas into molten slag; and
an exhaust gas treatment equipment 200 that treats combustion
exhaust gas G exhausted from the melting equipment 1A.
[0049] The fluidized-bed type gasification furnace 100 includes: a
waste injection hopper 101 through which waste D is injected; a
pusher-type first refuse feeding apparatus 102a that has an inlet
connected to the outlet of the waste injection hopper 101, and
pushes out the waste D in the horizontal direction; a connection
chute 102b that is connected to the outlet of the first refuse
feeding apparatus 102a at the top portion, and forms a vertically
extending space; a screw-type second refuse feeding apparatus 102c
having an inlet connected to the bottom portion of the connection
chute 102b; and a furnace main body 103 to which a fixed amount of
the waste D is supplied from the second refuse feeding apparatus
102c.
[0050] Combustion air B1 having, for example, a temperature of
approximately 120.degree. C. to 230.degree. C. and an air ratio of
approximately 0.2 to 0.7 is blown into the furnace main body 103
through a wind box 103a from the furnace bottom portion, and the
fluidized layer temperature is maintained at approximately
450.degree. C. to 600.degree. C. The furnace main body 103 turns
the waste D into thermally decomposed gas so as to decompose the
waste D into gas, gaseous tar and char (carbides). An incombustible
substance N is sequentially exhausted from an incombustible
substance exhaust opening 103b.
[0051] Char is gradually pulverized in the fluidized layer of the
furnace main body 103, and is introduced to a swirling melting
furnace 2 of the melting equipment 1A in conjunction with the gas
and gaseous tar. Hereinafter, the components that are introduced to
the swirling melting furnace 2 will be collectively referred to as
thermally decomposed gas C.
[0052] (Melting Equipment)
[0053] FIG. 2 is an enlarged view of the main parts of melting
equipment 1A.
[0054] As shown in FIG. 2, the melting equipment 1A is provided
with: the vertical swirling melting furnace (melting furnace) 2; a
secondary combustion chamber 8 disposed above the swirling melting
furnace 2; a slag extraction chute 7 that has a slag cut burner 7a
and guides slag generated in the swirling melting furnace 2
downward; a boiler 9 disposed on the downstream side of the
secondary combustion chamber 8; a granulation tank 10 provided
below the swirling melting furnace 2; and a bypass channel 20
connecting the slag extraction chute 7 and the secondary combustion
chamber 8.
[0055] As shown in FIGS. 1 and 2, the swirling melting furnace 2
includes a thermal decomposition gas burner 3 that mixes the
thermally decomposed gas C exhausted from the fluidized-bed type
gasification furnace 100 with combustion air B2 and blows the gas
mixture into the furnace.
[0056] In the swirling melting furnace 2, as shown in FIG. 2, the
gas mixture of the thermally decomposed gas C and the combustion
air B2 is combusted while forming a swirling flow so that the
temperature inside the furnace is maintained at 1300.degree. C. to
1500.degree. C., and ash in the thermally decomposed gas C is
melted and made into slag. The molten slag is attached to the inner
wall surface of the swirling melting furnace 2, flows downward, and
is exhausted into the granulation tank 10 through the slag
extraction chute 7 from a slag cinder notch 6 at the furnace bottom
portion.
[0057] The bypass channel 20, as shown in FIG. 2, has an ejector 21
that is provided on the way of the bypass channel 20 and suctions
the combustion exhaust gas G, and is configured to guide the
combustion exhaust gas G to the secondary combustion chamber 8 from
the slag extraction chute 7 through the bypass channel 20. That is,
the high-temperature combustion exhaust gas G continuously passes
through the slag cinder notch 6 so that solidification of the
molten slag is suppressed. The details of the bypass channel 20
will be described below in detail.
[0058] As shown in FIG. 1, the slag exhausted to the granulation
tank 10 is rapidly cooled in the granulation tank 10, transported
out through a slag conveyer 10a, and collected as granulated slag.
The collected granulated slag can be effectively used as roadbed
material and the like.
[0059] On the other hand, the combustion exhaust gas G exhausted
from the swirling melting furnace 2 is introduced to the secondary
combustion chamber 8 through a connection portion 5. The secondary
combustion chamber 8 combusts uncombusted components in the
combustion exhaust gas G using supplied combustion air B3. After
that, the combustion exhaust gas G is thermally collected in the
boiler 9, cooled to approximately 200.degree. C. to 250.degree. C.,
and sent to the exhaust gas treatment equipment 200.
[0060] Returning to FIG. 1, in the exhaust gas treatment equipment
200, the combustion exhaust gas G exhausted from the boiler 9 is
introduced to a temperature reduction tower 201, cooled to
approximately 150.degree. C. to 180.degree. C. by spraying water
directly, then, sprayed lime hydrate and activated char in a smoke
path according to necessity, and introduced to a reaction dust
collection apparatus 202.
[0061] In addition, in the reaction dust collection apparatus 202,
smoke dust, acidic gas, DXNs and the like in the combustion exhaust
gas G are removed, and then dust ash exhausted from the reaction
dust collection apparatus 202 is treated by a chemical treatment
and is landfilled. The combustion exhaust gas G from which smoke
dust, acidic gas, DXNs and the like are removed is reheated in a
steam heater 203, and NO.sub.x is removed in a catalyst reaction
apparatus 204, and then, the combustion exhaust gas is emitted in
the air through a chimney pipe 206 through an induction fan
205.
[0062] (Ejector)
[0063] FIG. 3 is an enlarged cross-sectional view of the ejector
21.
[0064] As shown in FIG. 3, the ejector 21 is provided with: a
cylinder portion 22 which has a cylindrical shape and a closed
bottom, and is connected to the bypass channel 20 through which the
combustion exhaust gas G flows; a contraction portion 23 in which
the channel cross section thereof become narrowed while extending
toward the downstream side of the cylinder portion 22; a radially
expanding portion 24 that is continuously provided to the
downstream side of the contraction portion 23; and a driving air
supply pipe 25 that is coaxially provided with the cylinder portion
22 and ejects high-pressure air A toward the downstream side from
the front end opening portion surrounded by the contraction portion
23.
[0065] The contraction portion 23 includes: a tapering portion 23a
having a diameter gradually contracting from the upstream of the
channel toward the downstream; and a small diameter portion 23b
that continues to the downstream side of the tapering portion 23a
and has a substantially constant diameter.
[0066] In the ejector 21, when the high-pressure air A is injected
from the driving air supply pipe 25, the flow velocity of the
high-pressure air A is increased through the contraction portion
23. The high-pressure air A having an increased flow velocity
entrains and flows the ambient combustion exhaust gas G toward the
downstream, and thus turns the upstream side of the ejector 21 into
a negative pressure. Thereby, the combustion exhaust gas G is
suctioned from the slag extraction chute 7 (refer to FIG. 2).
Meanwhile, the position of the ejector 21 may be appropriately
changed, and the flow direction of the high-pressure air A or the
introduction direction of the combustion exhaust gas G can also be
appropriately set.
[0067] (Adhesion-Prevention Unit) (Adhered Substance Removal
Portion)
[0068] As shown in FIG. 3, the ejector 21 having the above
configuration is provided with an adhesion-prevention unit 31 that
prevents adhesion of an incorporated substance that incorporates
into the combustion exhaust gas G. The adhesion-prevention unit 31
has an air knocker (adhered substance removal portion) 41 that
removes an adhered substance F that is attached to the inner wall
surface 21a of the ejector 21.
[0069] As shown in FIG. 3, the air knocker 41 is disposed so as to
strike the outer wall surface of the tapering portion 23a on the
small diameter portion 23b side and thus supply vibration to the
inner wall surface 21a of the ejector 21. The air knocker 41 does
not operate at all times, but operates on a regular basis.
[0070] Next, the operations of the adhesion-prevention unit 31 and
the air knocker 41 having the above configurations will be
described.
[0071] When the ejector 21 is driven in a state in which the air
knocker 41 is not in operation, the combustion exhaust gas G flows
through the bypass channel 20 from the slag extraction chute 7
toward the secondary combustion chamber 8 as shown in FIG. 2 due to
the above action. In the ejector 21, the combustion exhaust gas G
repeatedly collides with the inner wall surface 21a of the
contraction portion 23 such that a mixture that is entrained with
the combustion exhaust gas G is attached to and accumulated on the
inner wall surface 21a, and thus the adhered substance F grows.
[0072] The adhered substance F that is attached to and accumulated
on the inner wall surface 21a is composed of dust or salts that are
included in the combustion exhaust gas G, and the major components
are CaCl.sub.2, CaSO.sub.4, NaCl, Na.sub.2SO.sub.4, KCl,
K.sub.2SO.sub.4, SiO.sub.2, and Al.sub.2O.sub.3.
[0073] When a predetermined time elapses, the air knocker 41 comes
into operation. The air knocker 41 strikes the outer wall surface
of the ejector 21, and supplies vibration to the inner wall surface
21a of the ejector 21. The adhered substance F that is attached to
the inner wall surface 21a is fallen off by the vibration. The
adhered substance F that is fallen off from the inner wall surface
21a is entrained and flew by the high-pressure air A and the
combustion exhaust gas G toward the downstream side, made to flow
through the bypass channel 20, finally reaches the secondary
combustion chamber 8, and is combusted. Alternatively, the adhered
substance accumulates on the bottom portion of the ejector 21. The
accumulated substance in the ejector 21 is exhausted outside the
ejector 21 from a cleaning opening, not shown, by regular
cleanings.
[0074] In addition, the air knocker 41 operates for a certain time,
and then, again, comes into stop.
[0075] In the ejector 21 in which the adhered substance F is
removed as described above, the combustion exhaust gas G channel is
neither clogged nor narrowed, and the combustion exhaust gas G
stably circulates.
[0076] As described above, since the melting equipment 1A includes
the adhesion-prevention unit 31, adhesion of the incorporated
substance that incorporates into the combustion exhaust gas G
(dust, salts, or the like) to the inner wall surface 21 of the
ejector 21 is prevented. Thereby, the combustion exhaust gas G
channel is prevented from being clogged or narrowed, and therefore
the combustion exhaust gas G is capable of being stably
circulated.
[0077] In addition, since the air knocker 41 is included, the
adhered substance F is removed even when the incorporated substance
in the combustion exhaust gas G is attached to the inner wall
surface 21a of the ejector 21. Thereby, the channel of the
combustion exhaust gas G being clogged or narrowed is suppressed so
that the combustion exhaust gas G is capable of being stably
circulated.
[0078] In addition, since the air knocker 41 supplies vibration to
the inner wall surface 21a of the ejector 21, the adhered substance
F on the inner wall surface 21a of the ejector 21 is capable of
being removed without inhibiting the smooth flow of the combustion
exhaust gas G or the high-pressure air A in the ejector 21.
Furthermore, the configuration of the apparatus becomes simple.
[0079] In the above configuration, the number of the air knocker 41
used is single, but may be plural. In a case in which a plurality
of the air knockers 41 is used, when the air knockers are provided
at substantially equal intervals in the circumferential direction
of the gas channel cross section, vibration is capable of being
evenly supplied to the inner wall surface 21a, and the adhered
substance F locally remaining on the inner wall surface 21a of the
ejector 21 can be suppressed.
[0080] In addition, in the above configuration, the air knocker 41
is used, but the ejector may be driven by oil pressure, or
vibration may be supplied by a motor as long as vibration can be
supplied to the inner wall surface 21a of the ejector 21.
[0081] In addition, in the above configuration, the air knocker 41
is operated on a regular basis, but may be operated at all
times.
[0082] In addition, the frequencies of vibration supplied to the
inner wall surface 21a may be changed by changing timings at which
the air knocker 41 strikes the outer wall surface.
First Modified Example of the First Embodiment
[0083] FIG. 4 is an enlarged cross-sectional view of an ejector 21A
according to a first modified example of the first embodiment.
[0084] As shown in FIG. 4, an adhesion-prevention unit 32 is
provided with the ejector 21A. The adhesion-prevention unit 32 has
an air bluster (adhered substance removal portion) 42 that removes
the adhered substance F that is attached to the inner wall surface
21a of the ejector 21A.
[0085] The air bluster 42 is formed into a long shape, and
compressed air a is injected from a front end portion 42a. The air
bluster 42 extends substantially along the driving air supply pipe
25 from an end wall 21b of the ejector 21A (cylinder portion 22) to
the vicinity of the contraction portion 23 (tapering portion
23a).
[0086] The end wall 21b of the ejector 21A has a dual structure.
The end wall 21b is configured to overlap an inner end wall 21c
having a circular hole 21e formed therein and an outer end wall 21d
that is provided so as to be rotatable with respect to the inner
end wall 21c, and seals the ejector 21A air-tightly.
[0087] The air bluster 42 is movably inserted to the circular hole
21e of the inner end wall 21c so as to be rotatable in the
circumferential direction of the channel cross section. In
addition, the air bluster 42 penetrates the outer end wall 21d in a
state in which the air tightness with the outer end wall 21d is
secured, is refrained so as to be relatively rotating with respect
to the outer end wall 21d, and is capable of being relatively moved
in the tube axial direction of the cylinder portion 22.
[0088] The above configuration enables the front end portion 42a of
the air bluster 42 to face the contraction portion 23 of the
ejector 21A throughout the entire circumstance and to stay ready at
the bottom while not in operation.
[0089] According to the air bluster 42, since the compressed air a
is blown to the inner wall surface 21a of the ejector 21A, the
removed adhered substance F is capable of being rapidly joined into
the flow of the high-pressure air A that is injected by the ejector
21A. Thereby, the adhered substance F is capable of being blown
more reliably into the secondary combustion chamber 8 on the
downstream side. Furthermore, the adhered substance F that falls
and remains on the end wall 21b is capable of being decreased, and
it is possible to reduce efforts for maintenance, such as
cleaning.
[0090] In addition, since the air bluster is capable of being
rotated substantially the entire circumference in the
circumferential direction in the channel cross section of the
contraction portion 23 of the ejector 21A, the adhered substance F
that is attached to the inner wall surface 21a of the contraction
portion 23 is capable of being removed throughout the entire
circumference in the circumferential direction in the channel cross
section without remainder. In addition, since only one air bluster
42 is provided, the space factor of the ejector 21A can be
improved.
Second Modified Example of the First Embodiment
[0091] FIG. 5 is an enlarged cross-sectional view of an ejector 21B
according to a second modified example of the first embodiment.
[0092] As shown in FIG. 5, the ejector 21B is provided with an
adhesion-prevention unit 33. The adhesion-prevention unit 33
includes a washing brush (adhered substance removal portion) 43
that removes the adhered substance F that is attached to the inner
wall surface 21a of the ejector 21B.
[0093] The washing brush 43 is formed into a long shape, and has a
number of washing bristles at a front end portion 43a. The washing
brush 43 extends substantially along the driving air supply pipe 25
from the end wall 21b of the ejector 21 to the vicinity of the
contraction portion 23.
[0094] Similarly to the air bluster 42, the washing brush 43 is
configured so as to be rotatable in the circumferential direction
of the channel cross section and movable in the tube axial
direction of the cylinder portion 22. The washing brush 43 stays
ready at the bottom while not in operation, and moves the front end
portion 43a toward the contraction portion 23 side so as to bring
the washing bristles into contact with the adhered substance F
while in operation. In addition, the washing brush 43 rotates in
the circumferential direction of the channel cross section while
advancing and retreating in the tube axial direction of the
cylinder portion 22 so as to mechanically wash the adhered
substance F.
[0095] According to the above configuration, since the washing
brush 43 mechanically washes the inner wall surface 21a of the
ejector 21, the adhered substance F on the inner wall surface 21a
of the ejector 21 can be directly removed, and even strongly fixed
adhered substance F can be removed more reliably.
[0096] In the above configuration, the air bluster 42 and the
washing brush 43 are rotated, but may remain still.
[0097] In the above configuration, the numbers of the air bluster
42 and the washing brush 43 that are provided are single, but may
be plural.
[0098] In addition, in the above configuration, the air bluster 42
and the washing brush 43 are provided, but may be provided together
or in an overlapping manner the air knocker 41.
[0099] In addition, in the above configuration, the air bluster 42
and the washing brush 43 are configured to be automatically
operated, but may be operated manually so as to remove the adhered
substance F.
Second Embodiment
[0100] FIG. 6 is an enlarged view of the main parts of melting
equipment 1B according to a second embodiment of the invention.
[0101] In FIG. 6, the same configuration components as in FIGS. 1
to 5 will be given to the same reference signs, and a description
thereof will not be made.
[0102] As shown in FIG. 6, the melting equipment 1B includes an
adhesion-prevention unit 34. The adhesion-prevention unit 34
includes a cyclone separator (swirling separation portion) 44
provided upstream of the ejector 21 in the bypass channel 20. The
cyclone separator 44 swirls the introduced combustion exhaust gas G
so as to form a swirling flow, and centrifugally separates an
incorporated substance included in the swirling flow. The cyclone
separator 44 includes a cooling system 44b that cools an inner wall
44a along which the swirling flow of the combustion exhaust gas G
flows. The cooling system 44b cools the temperature of the inner
wall 44a to the solidification point or lower of volatile salts
(volatilized salts) included in the combustion exhaust gas G.
[0103] Next, the operations of the adhesion-prevention unit 34 and
the cyclone separator 44 having the above configuration will be
described.
[0104] When the combustion exhaust gas G is suctioned into the
bypass channel 20 due to a negative pressure, the combustion
exhaust gas G is guided to the cyclone separator 44. The cyclone
separator 44 forms a swirling flow by flowing the combustion
exhaust gas G along the inner wall 44a. In addition, the
incorporated substance included in the combustion exhaust gas G is
centrifugally separated, and guided downward while the incorporated
substance collides with the inner wall 44a and moves in a swirling
form.
[0105] At this time, since the inner wall 44a is cooled to a
temperature that is equal to or lower than the solidification point
of the salts included in the combustion exhaust gas G, the volatile
salts in the combustion exhaust gas G are solidified, and guided
downward in the same manner as above.
[0106] The combustion exhaust gas G from which the incorporated
substance and the volatile salts are removed is exhausted from the
cyclone separator 44 and guided to the ejector 21. The combustion
exhaust gas G introduced to the ejector 21 is entrained by the
high-pressure air A injected from the driving air supply pipe 25
and is flowed toward the downstream side along the inner wall
surface 21a of the contraction portion 23; however, the
incorporated substance and the volatile salts have been removed,
the adhered substance F is not easily attached to the inner wall
surface 21a of the contraction portion 23.
[0107] As described above, since the cyclone separator 44 that
centrifugally separates the incorporated substance included in the
swirling flow is included upstream of the contraction portion 23 of
the ejector 21, it is possible to reduce the incorporated substance
being reached the contraction portion 23. Thereby, the adhered
substance F that is attached to the contraction portion 23 of the
ejector 21 (refer to FIG. 3) can be reduced.
[0108] In addition, since the inner wall 44a of the cyclone
separator 44 is cooled, the volatile salts included in the
combustion exhaust gas G is capable of being solidified and
separated. Thereby, the adhered substance F that is attached to the
inner wall surface 21a of the contraction portion 23 of the ejector
21 can be further reduced.
[0109] Even in the above configuration, when the melting equipment
1B is operated for a long time, there is a possibility of the
adhered substance F being generated on the inner wall surface 21a
of the contraction portion 23 of the ejector 21. When the
adhesion-prevention unit 34 is configured by adding at least one of
the air knocker 41, the air bluster 42, and the washing brush 43 in
the first embodiment together with the cyclone separator 44 in
order to remove the adhered substance F, the combustion exhaust gas
G channel is capable of being more reliably prevented from being
clogged or narrowed, and the combustion exhaust gas G can be more
stably circulated.
First Modified Example of the Second Embodiment
[0110] FIG. 7 is a schematic configuration view of melting
equipment 1B1 according to a first modified example of the second
embodiment.
[0111] In the above described melting equipment 1B, a single
ejector 21 provided at the downstream of the cyclone separator 44,
but the melting equipment 1B1 is provided with a plurality of the
ejectors 21 in a row as shown in FIG. 7.
[0112] According to the above configuration, since two ejectors 21
are provided in a row, in a case in which the cyclone separator 44
having a large pressure loss is provided, a greater negative
pressure is capable of being exerted on the downstream side of the
cyclone separator 44, and the combustion exhaust engine G is
capable of being favorably guided to the bypass channel 20 even
when the gas flow velocity that is set in the ejector 21 cannot be
increased.
[0113] It is needless to say that three or more ejectors 21 may be
provided in a row.
Second Modified Example of the Second Embodiment
[0114] FIG. 8 is an enlarged cross-sectional view of the main parts
of melting equipment 1B2 according to a second modified example of
the second embodiment.
[0115] As shown in FIG. 8, the melting equipment 1B2 includes an
adhesion-prevention unit 35. The adhesion-prevention unit 35 has a
swirling separation cylinder (swirling separation portion) 22x that
consists a part of an ejector 26.
[0116] The ejector 26 is provided instead of the ejector 21. The
ejector 26 not only includes the contraction portion 23 and the
radially expanding portion 24, but also has the swirling separation
cylinder (swirling separation portion) 22x disposed in a portion
corresponding to the cylinder portion 22 in the ejector 21.
[0117] The swirling separation cylinder 22x has the cylinder axis
in the substantially vertical direction. The swirling separation
cylinder 22x is schematically consisted of a fixed diameter portion
26a that is formed in a substantially fixed diameter and has an
introduction opening 26f through which the combustion exhaust gas G
is introduced from the tangential direction, formed therein, a
taper portion 26b that continues to the bottom of the fixed
diameter portion 26a and has a diameter gradually contracting
downward. The swirling separation cylinder 22x further includes an
inner circumferential partition 26d dropping from the entire
circumference of the edge portion of a gas outlet 26c that opens at
the top portion of the fixed diameter portion 26a, and an
incorporated substance exhausting portion 26e formed at the lower
end of the taper portion 26b.
[0118] In addition, the ejector is configured that the contraction
portion 23 disposed on the top of the gas outlet 26c and the
driving air supply pipe 25 penetrates through the gas outlet 26c
and the incorporated substance exhausting portion 26e.
[0119] That is, when the combustion exhaust gas G is introduced
from the introduction opening 26f, the combustion exhaust gas G
flows along the inner circumferential wall of the fixed diameter
portion 26a so that the swirling flow of the combustion exhaust gas
G is formed, and the incorporated substance included in the
combustion exhaust gas G is centrifugally separated. The
centrifugally separated incorporated substance collides with the
inner wall 44a of the taper portion 26b so as to be guided downward
while moving in a swirling shape, and is exhausted from the
incorporated substance exhausting portion 26e (indicated by
reference sign fin FIG. 8). On the other hand, the combustion
exhaust gas G from which the incorporated substance is separated is
exhausted from the gas outlet 26c on the top. At this time, since
the inner circumferential partition 26d prevents interruption
between the combustion exhaust gas G exhausted from the gas outlet
26 and the combustion exhaust gas G introduced from the
introduction opening 26f, it is possible to suppress that the
incorporated substance included in the combustion exhaust gas G
that is newly introduced from the introduction opening 26f is
exhausted from the gas outlet 26c.
[0120] In the above manner, the combustion exhaust gas G exhausted
from the gas outlet 26c is wound by the high-pressure air that is
injected from the driving air supply pipe 25 and is flowed to the
downstream side.
[0121] Even in this case, since the incorporated substance of the
combustion exhaust gas G is removed, the adhered substance F is not
easily generated on the inner wall surface 21a of the contraction
portion 23 in the ejector 26, and the same effect as the above
effect can be obtained.
[0122] The adhesion-prevention unit 35 may be configured by
providing the cyclone separator 44, the air knocker 41, the air
buster 42, and the washing brush 43 in addition the ejector 26. The
air blaster 42 and the washing brush 43 may be provided at
locations at which the fixed diameter portion 26a and the like are
not interrupted. In addition, similarly to the above described
cyclone separator 44, the adhesion-prevention unit may be
configured to cool the fixed diameter portion 26a and the inner
circumferential wall of the taper portion 26b.
Third Embodiment
[0123] FIG. 9 is an enlarged cross-sectional view of the principal
parts of melting equipment 1C according to a third embodiment of
the invention. Meanwhile, in FIG. 9, the same configuration
components as in FIGS. 1 to 8 will be given the same reference
signs, and description thereof will not be made.
[0124] As shown in FIG. 9, the melting equipment 1C has almost the
same configuration as the melting equipment 1A, but there is a
difference in that an ejector 27 is provided instead of the ejector
21. The ejector 27 is provided with an adhesion-prevention unit 36.
The adhesion-prevention unit 36 has a plurality of air supply pipes
(air film forming portion) 45.
[0125] The air supply pipe 45 opens the beginning end of the
contraction portion 23 on the upstream side, ejects air s, and
forms an air film along the inner wall surface 21a of the ejector
27. That is, when the air s is supplied from the air supply pipe
45, the air s is absorbed into the flows of the combustion exhaust
gas G and the high-pressure air A, and an air film that flows
toward the downstream side along the inner wall surface 21a is
formed.
[0126] Thereby, the incorporated substance included in the
combustion exhaust gas G does not easily reach the inner wall
surface 21a of the ejector 27. Thereby, the adhered substance that
is attached to the contraction portion 23 is capable of being
reduced.
Modification Example of the Third Embodiment
[0127] FIG. 10 is a schematic configuration view showing an
adhesion-prevention unit 36A according to a modified example of the
third embodiment of the invention.
[0128] As shown in FIG. 10, the adhesion-prevention unit 36A
includes a driving air supply pipe (air film forming portion) 46
that forms an air film along the inner wall surface 21a of the
ejector 28.
[0129] The driving air supply pipe 46 supplies the high-pressure
air A as the driving air of the ejector 28. That is, in the ejector
28, the driving air supply pipe 46 that introduces the
high-pressure air A as the driving air to the cylinder portion 22
is opened, the bypass channel 20 that introduces the combustion
exhaust gas G is penetrated through the cylinder portion 22, and
includes the front end opening portion surrounded by the
contraction portion 23. The ejector has a reverse position
relationship with respect to the driving air supply pipe 25 and the
bypass channel 20 of the above described ejector 21.
[0130] According to the adhesion-prevention unit 36A, the
high-pressure air A flows along the inner wall surface 21a of the
ejector 28 and forms an air film, and the combustion exhaust gas G
flows toward the downstream side from the bypass channel 20 in a
state of being surrounded by the air film. Thereby, the
incorporated substance included in the combustion exhaust gas G
does not easily reach the inner wall surface 21a of the ejector 28.
As a result, it is possible to reduce the incorporated substance
being attached to the contraction portion 23 of the ejector 28.
Fourth Embodiment
[0131] FIG. 11 is a schematic configuration view showing melting
equipment 1D according to a fourth embodiment of the invention. In
FIG. 11, the same configuration components as in FIGS. 1 to 10 will
be given the same reference signs, and description thereof will not
be made.
[0132] As shown in FIG. 11, the melting equipment 1D includes an
adhesion-prevention unit 37. The adhesion-prevention unit 37 has
two branching channels 62A and 62B that are provided in series in a
bypass channel 62.
[0133] The two branching channels 62A and 62B branch at a branching
portion 62a on the upstream side, join at a combining portion 62b
on the downstream side. The branching channels 62A and 62B includes
the ejectors 21 respectively.
[0134] The branching portion 62a is provided with a changeover
valve 62c so that the combustion exhaust gas G is capable of being
selectively blown into only one of the branching channels 62A and
62B.
[0135] According to the above configuration, since the bypass
channel 62 has the branching channels 62A and 62B, and the ejector
21 is provided at each of the branching channels 62A and 62B, it is
possible to circulate the combustion exhaust gas G using one of the
branching channels 62A and 62B (for example, the branching channel
62A) and to clean the ejector in the other (for example, the
branching channel 62B). Therefore, the adhered substance F on the
inner wall surface 21a of the ejector 21 can be removed by cleaning
the ejector 21 while continuing the operation of the melting
equipment 1D.
[0136] It is needless to say that three or more branching channels
may be provided.
Fifth Embodiment
[0137] FIG. 12 is a schematic configuration view showing melting
equipment 1E according to a fifth embodiment of the invention. In
FIG. 12, the same configuration components as in FIGS. 1 to 11 will
be given the same reference signs, and description thereof will not
be made.
[0138] As shown in FIG. 12, the melting equipment 1E includes an
adhesion-prevention unit 38. The adhesion-prevention unit 38
includes a fume cleaning tower (liquid dispersion portion) 70 that
removes the incorporated substance included in the combustion
exhaust gas G by sprinkling water to the combustion exhaust gas G,
at the upstream of the ejector 21.
[0139] The fume cleaning tower 70 includes a casing 71; a pump 72
that sprinkles water that is stored at the bottom portion of the
casing 71 from the top portion of the casing 71; a filler layer 73
that is formed in, for example, a ring shape so as to receive
sprinkled water, and holds water on the surface so as to promote
gas-liquid contact, and a demister 74 that is provided at an outlet
of the casing 71.
[0140] The ejector 21 is configured to be driven using the
high-pressure air A having a temperature that is equal to or higher
than the melting point.
[0141] According to the above configuration, since the fume
cleaning tower 70 is included upstream of the ejector 21, the
incorporated substance that reaches the contraction portion 23 of
the ejector 21 is capable of being reduced. Thereby, it is possible
to reduce the adhered substance F being attached to the contraction
portion 23 of the ejector 21.
[0142] In addition, since the demister 74 arranged at the outlet of
the casing 71 is provided, it is possible to prevent misty water
from flowing into the ejector 21 and the bypass channel 20 on the
downstream side. Furthermore, since the high-pressure air A in the
ejector 21 is at the melting point or higher, even when misty water
is included in the combustion exhaust gas G due to water
sprinkling, it is possible to prevent a water from attaching on the
inner wall surface 21a in the ejector 21 and the wall surface of
the bypass channel 20 by vaporizing the moisture. Thereby, since
the residual incorporated substance in the combustion exhaust gas G
is prevented from being trapped by water attached on the inner wall
surface 21a of the ejector 21 and the wall surface of the bypass
channel 20, and therefore the combustion exhaust gas G is capable
of being stably circulated by preventing the clogging or narrowing
of the combustion exhaust gas G channel.
[0143] The operation sequences, the shapes, combination, and the
like of the respective component members as shown in the
embodiments described above are an example, and various
modifications are permitted based on design requirements within the
scope of the invention.
INDUSTRIAL APPLICABILITY
[0144] According to the melting equipment according to the
invention, it is possible to stably circulate combustion exhaust
gas by suppressing clogging or narrowing of the channel of
combustion exhaust gas.
DESCRIPTION OF THE REFERENCED SYMBOLS
[0145] 1A, 1B, 1B1, 1B2, 1D, 1E MELTING EQUIPMENT [0146] 2 SWIRLING
MELTING FURNACE (MELTING FURNACE) [0147] 7 SLAG EXTRACTION CHUTE
[0148] 8 SECONDARY COMBUSTION CHAMBER [0149] 20 BYPASS CHANNEL
[0150] 21 (21A, 21B), 26 TO 28 EJECTOR [0151] 21a INNER WALL
SURFACE [0152] 22x SWIRLING SEPARATION CYLINDER (SWIRLING
SEPARATION PORTION) [0153] 23 CONTRACTION PORTION [0154] 25 DRIVING
AIR SUPPLY PIPE [0155] 31 TO 36, 36A, 37, 38 ADHESION-PREVENTION
UNIT [0156] 41 AIR KNOCKER (ADHERED SUBSTANCE REMOVAL PORTION)
[0157] 42 AIR BLUSTER (ADHERED SUBSTANCE REMOVAL PORTION) [0158] 43
WASHING BRUSH (ADHERED SUBSTANCE REMOVAL PORTION) [0159] 44 CYCLONE
SEPARATOR(SWIRLING SEPARATION PORTION) [0160] 44a INNER WALL [0161]
44b COOLING SYSTEM [0162] 45 AIR SUPPLY PIPE (AIR FILM FORMING
PIPE) [0163] 46 DRIVING AIR SUPPLY PIPE (AIR FILM FORMING PIPE)
[0164] 62 BYPASS CHANNEL [0165] 62A, 62B BRANCHING CHANNEL [0166]
70 FUME CLEANING TOWER (LIQUID DISPERSION PORTION) [0167] A
HIGH-PRESSURE AIR [0168] F ADHERED SUBSTANCE [0169] G COMBUSTION
EXHAUST GAS [0170] S AIR (AIR FILM)
* * * * *