U.S. patent application number 11/884810 was filed with the patent office on 2008-11-06 for coke oven doors having heating function.
This patent application is currently assigned to Yamasaki Industries Co,, Ltd.. Invention is credited to Kesao Yamasaki.
Application Number | 20080271985 11/884810 |
Document ID | / |
Family ID | 36927303 |
Filed Date | 2008-11-06 |
United States Patent
Application |
20080271985 |
Kind Code |
A1 |
Yamasaki; Kesao |
November 6, 2008 |
Coke Oven Doors Having Heating Function
Abstract
An air chamber unit provided for a coke oven door enabling to
suppress the generation of poor quality coke and reduce tar
adhesion to coke oven door by accelerating coking reaction in the
vicinity of coke oven door plug. An air chamber unit (17) is
installed to control air supply to the bottom-less combustion space
provided in hollow metallic coke oven door plug. For the purpose of
long lasting stable air supply for said combustion space, air space
(20) in the air chamber unit (17) is divided into two sections (A)
and (B) by labyrinth partition to give different function for each
of those section. Air intake pipe (27) is fitted in section (A)
through bottom plate (21) of air chamber unit (17), wherein check
valve plate (35) and other related components are provided as air
supply control segments. Air supply pipe (30) or air delivery cup
having one or more air inlet holes in upper portion is fitted in
section (B) through bottom plate (21) of air chamber unit (17),
wherein roles to remove contaminant particles suspended in backward
flow gas are provided.
Inventors: |
Yamasaki; Kesao; (Fukuoka,
JP) |
Correspondence
Address: |
JORDAN AND HAMBURG LLP
122 EAST 42ND STREET, SUITE 4000
NEW YORK
NY
10168
US
|
Assignee: |
Yamasaki Industries Co,,
Ltd.
Kitakyushu-shi
JP
|
Family ID: |
36927303 |
Appl. No.: |
11/884810 |
Filed: |
February 20, 2006 |
PCT Filed: |
February 20, 2006 |
PCT NO: |
PCT/JP2006/302949 |
371 Date: |
August 21, 2007 |
Current U.S.
Class: |
202/248 |
Current CPC
Class: |
C10B 25/06 20130101 |
Class at
Publication: |
202/248 |
International
Class: |
C10B 25/06 20060101
C10B025/06 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 22, 2005 |
JP |
2005-084745 |
Mar 24, 2005 |
JP |
2005-122919 |
Claims
1. An air chamber unit being connected to bottom-less combustion
space provided in hollow metallic door plug of a coke oven door
comprising: an air space divided into two sections 1 and 2 by a
plurality of labyrinth partition plates working as gas passage
guide; said section 1 equipped with air intake pipe having
horizontal top edge inserted into said section 1 through bottom
plate of said air chamber unit; said section 2 equipped with air
supply pipe or air supply cup having at least one air inlet hole
laterally in upper part of said air supply pipe or air supply cup
being inserted through said bottom plate of said air chamber unit;
top end of said air supply pipe or at least one air inlet hole of
said air supply cup to work as air inlet; lower end of said air
supply pipe or said air supply cup to work as air exit; exit end of
said air supply pipe or air supply cup connecting to air supply
line supplying air to said bottom-less combustion space provided in
said hollow metallic door plug; a removable check valve plate
mounted on top of said air intake pipe delivery end; a suspension
coil spring fitted surrounding said air intake pipe to keep said
check valve plate in floating position; at least one guide piece
arranged outside of said suspension coil spring assuring correct up
and down movement of said check valve plate; a stopper plate
supported and placed above said check valve plate by said guide
piece to prevent excess jump-up of said check valve plate; a
cylinder-shaped air and/or gas flow guide plate fitted to exterior
of upper part of said guide pieces keeping gap between said guide
piece and said guide plate; a ring fitted to the lower surface of
said check valve plate to keep appropriate relative position
between said check valve plate and said coil spring head within a
preferred range; and another ring fixed on a said ring-bracket
fitted to said air intake pipe body or to said bottom plate of said
air chamber unit keeping the bottom end of said suspension coil
spring within a preferred position.
2. An air chamber unit connected to bottom-less combustion space
provided in hollow metallic door plug of a coke oven door
comprising: an air space divided into two sections 1 and 2 by a
plurality of labyrinth partition plates working as gas passage
guide; said section 1 equipped with air intake pipe with horizontal
top edge inserted into said section 1 through bottom plate of said
air chamber unit; said section 2 equipped with air supply pipe or
air delivery cup having at least one air inlet hole laterally in
its upper part of said air supply pipe or air delivery cup being
inserted through said bottom plate of said air chamber unit; top
end of said air supply pipe or at least one air inlet hole of said
air delivery cup to work as air inlet; lower end of said air supply
pipe or said air delivery cup to work as air exit; exit end of said
air supply pipe or air delivery cup connecting to air supply line
supplying air to said bottom-less combustion space provided in said
hollow metallic door plug; a hood with a diameter larger than that
of said air supply pipe or said air supply cup with its bottom up
position installed in said section 2 to provide a gas stagnant
space; a removable check valve plate mounted on top of said air
intake pipe delivery end; a suspension coil spring fitted
surrounding said air intake pipe keeping said check valve plate in
floating position; one or more guide pieces arranged outside of
said suspension coil spring assuring correct up and down movement
of said check valve plate; a stopper plate supported and placed
above said check valve plate by said guide pieces to prevent excess
jump-up of said check valve plate; a cylinder shaped air and/or gas
flow guide plate fitted to exterior of upper part of said guide
pieces keeping gap between said guide pieces and said guide plate;
a ring fitted to the lower surface of said check valve plate
keeping appropriate relative position between said check valve
plate and said coil spring head within a preferred range; and
another ring fixed on a said ring-bracket fitted to said air intake
pipe body or to said bottom plate of said air chamber unit keeping
the bottom end of said suspension coil spring within a preferred
position.
3. An air chamber unit being connected to bottom-less combustion
space provided in hollow metallic door plug of a coke oven door
comprising: an air space divided into two sections 1 and 2 by a
plurality of labyrinth partition plates working as gas passage
guide; said section 1 equipped with air intake pipe having
horizontal top edge inserted into said section 1 through bottom
plate of said air chamber unit; said section 2 equipped with air
supply pipe or air delivery cup having at least one air inlet hole
in upper portion of said air supply pipe or air delivery cup being
inserted through said bottom plate of said air chamber unit;
impingement vanes or pieces inserted inside of said air supply pipe
or air delivery cup; said section 2 equipped with said air supply
pipe or said air delivery cup; exit end of said air supply pipe or
said air delivery cup connecting to air supply line sending air to
said bottom-less combustion space of said hollow metallic door
plug; a removable check valve plate mounted on top of said air
intake pipe delivery end; a suspension coil spring being fitted
surrounding said air intake pipe keeping said check valve plate in
floating position; at least one guide piece arranged outside of
said suspension coil spring assuring correct up and down movement
of said check valve plate; a stopper plate supported and placed
above said check valve plate by said guide piece to prevent excess
jump-up of said check valve plate; a cylinder-shaped air and/or gas
flow guide plate being fitted to exterior of upper part of said
guide piece keeping gap between said guide piece and said guide
plate; a ring fitted to the lower surface of said check valve plate
keeping appropriate relative position between said check valve
plate and said coil spring head within a preferred range; and
another ring fixed on a said ring-bracket being fitted to said air
intake pipe body or to said bottom plate of said air chamber unit
to keep the bottom end of said suspension coil spring within a
preferred position.
4. An air chamber unit being connected to bottom-less combustion
space provided in hollow metallic door plug of a coke oven door
comprising: an air space divided into two sections 1 and 2 by a
plurality of labyrinth partition plates which work as gas passage
guide; said section 1 equipped with air intake pipe with horizontal
top edge inserted into said section 1 through bottom plate of said
air chamber unit; said section 2 equipped with air supply pipe or
air delivery cup having at least one air inlet hole laterally in
upper portion of said air supply pipe or air delivery cup being
inserted through bottom plate of said air chamber unit; a hood
having a diameter larger than that of said air supply pipe or said
air delivery cup being fitted to above said air supply pipe or said
air delivery cup to provide a gas stagnant space in said section 2;
a removable check valve plate mounted on top of said air intake
pipe delivery end; a suspension coil spring fitted to surrounding
said air intake pipe to keep said check valve plate in floating
position; at least one guide piece arranged outside of said
suspension coil spring assuring correct up and down movement of
said check valve plate; a stopper plate supported and placed above
said check valve plate by said guide pieces to prevent excess
jump-up of said check valve plate; a cylinder shaped air and/or gas
guide plate fitted to exterior of upper part of said guide pieces
keeping gap between said guide pieces and said guide plate; a ring
fitted to the lower surface of said check valve plate to keep
appropriate relative position between said check valve plate and
said coil spring head within a preferred range; and another ring
fixed on a said ring-bracket fitted to said air intake pipe body or
to said bottom plate of said air chamber unit to keep the bottom
end of said suspension coil spring within a preferred position.
5. An air chamber unit of a coke oven door according to any one of
claims 1 to 4, further including; more than two plates shorter than
the distance between top and bottom plate of said air chamber unit;
top or bottom edge of each of said plates fixed to top or bottom
plate of said air chamber unit; said plates provided additional gas
passage opening on their left or right corners; and labyrinth unit
structured by said plates as labyrinth elements.
6. An air chamber unit of a coke oven door according to claims 3 or
4, further including impingement vanes or pieces mounted on
suspension shaft being fixed to top plate of air chamber unit or
top of air delivery cup.
Description
TECHNICAL FIELD
[0001] This invention relates to coke oven door implemented by
hollow metallic door plug having bottom-less gas combustion space
to provide heating function, which accelerates coking reaction of
coal particles charged in the vicinity of coke oven door plug,
gasifying of tar generated during coking and adhered to door and,
at the same time, preventing charged coal particles enter into
bottom-less combustion space of hollow metallic door plug.
BACKGROUND ART
[0002] Coke battery manufactures coke by heating coal particles by
the heat supplied through heating walls on both sides of coking
chamber of coke oven. Hot coke pushed out from coke oven includes
poor quality coke generated in the vicinity of both ends of coke
oven because of insufficient coking. This poor quality coke causes
low yield of good quality blast furnace coke. This problem arises
from existing refractory door plug, which usually has about 400 mm
of thickness and is heated up to a high temperature during coking
operation. Heated plug is exposed to the open air when door is
extracted from its service position and looses heat by radiation.
When door is put in service again temperature of door plug is lower
than before and it causes a delay of coking of coal particles
charged in the vicinity of door plug in next coking cycle.
[0003] To solve this problem, many heating type coke oven doors
have been invented to accelerate temperature rise of coal layer in
the vicinity of door plug by utilizing the sensible heat of high
temperature gas generated in coking chamber as a heating agent. For
example, Patent Document 1 discloses a "method for coking coal
particles charged in the vicinity of high heat conductive metal
wall of coke oven door plug by sending the generated hot coke oven
gas to the gas passage through the vertical flue provided in at
least one of the doors in contact with said coal charge and
separated from the interior of the coke oven by the heat conductive
metal wall constituting said door and moving part of said hot gas
to an upper end region in contact with said partition wall
therethrough by the ascending of said gas and the heat conductivity
of the partition wall" and Patent Document 2 discloses a "coke oven
door carrying on the inner side thereof a shield allowing passage
of gases generated in the oven that comprises shielding members
made up of spacers and coking plates".
[0004] Known coke oven door structures, such as those shown in
Patent Document 3 and Patent Document 4 disclose coke oven door,
said Coking Plate, provided gas passageway from bottom to top of
its hollow plug. A part of gas generated in coking chamber flows
into the hollow space and then is ignited by properly placed
ignition device. Necessary air or oxygen to burn the gas is
supplied from outside of the door. Although this type doors,
compared with those existing coke oven door using refractory plug,
may have effects to increase coking speed of coal particles charged
in the vicinity of coke oven door plug and decrease the generation
of poor quality coke, but have not come to industrial use. Possibly
this is because of several reasons such as quick distortion of
"coking plate" structured by steel plates caused by cyclic rapid
heating-cooling during door open-close operation, scratch damage of
coking chamber brick wall by distorted "coking plate" and
contamination of product coke by fragments of oven wall bricks
generated by distorted coking plate scratching. In addition,
maintenance of ignition control system for individual door of a
coke battery consists of 50 to 80 ovens is not practical under the
bitter operating condition of high temperature and dusty
atmosphere. Moreover, gas pressure behavior in the period later
than middle of a coking cycle is too complicated and unpredictable
to follow.
[0005] The inventor, considering above-mentioned situation,
developed a coke oven door having heating function comprising air
supply nozzle having air delivery-end in bottom-less combustion
space of hollow metallic coke oven door plug to burn coke oven gas
generated in the coking chamber and coming into said bottom-less
combustion space of hollow metallic coke oven door plug as shown in
Patent Document 5 and Patent Document 6. Air volume to be supplied
is neither controlled by means of electric nor manual system but
automatically determined following the behavior of gas pressure in
the bottom-less combustion space of hollow metallic plug by
movement of specially designed valve. The structure of hollow
metallic coke oven door plug consists of exchangeable metallic bars
and supporting brackets mounted on the coke oven side surface of
insulation boxes mounted on door body. Bars hang on supporting
brackets mounted on said insulation boxes having certain pitches
over the length of oven door giving narrow slits between each bar.
Width of slit is large enough to let the gas generated in the coke
oven flow into said bottom-less combustion space of hollow metallic
door plug but not large as to allow charged coal particles enter
into said bottom-less combustion space of hollow metallic door
plug. The inventor, as shown in Patent Document 7 and Patent
Document 8 (filed in Japan), also developed an air supply system
equipped with a kind of check valve to protect the system itself
from poor controllability caused by adhesion of viscous tar mist,
small coal and/or coke particles suspended in the backward flowing
coke oven gas. This system consists of a disk plate positioned at
the top end of air intake pipe capable of moving up and down
functioning as a check valve according to the gas pressure change
in said bottom-less combustion space of hollow metallic door plug
and additional device positioned between above-mentioned check
valve and delivery end of air supply pipe for separating tar mist
and small solid, coal and/or coke, particles. Above-mentioned
additional device is an impingement type separator set inside of
air supply pipe. This coke oven door raises the temperature of coal
particle layer in the vicinity of coke oven door plug and, at the
same time, makes said solid particles and tar adhering to the foot
of door plug disappear by heat generated by burning coke oven gas
flowing into said bottom-less combustion space of hollow metallic
door plug through the slits of metallic bars by supplying necessary
amount of combustion air from outside of coking chamber. It is
known, however, that the gas pressure in coking chamber fluctuates
all through the coking cycle with a considerably wide range from
positive to negative pressure. These phenomena may cause backward
flowing of gas accompanied by said small solid particles with
viscous tar mist and also clogging of air supply system in spite of
above-mentioned counter measures.
REFERENCE PATENTS
[0006] Patent Document 1: JP H3-40074 B
[0007] Patent Document 2: JP S61-49353 B
[0008] Patent Document 3: JP 2953319 B
[0009] Patent Document 4: JP H8-283735 A
[0010] Patent Document 5: JP 2004-99859 A
[0011] Patent Document 6: WO2004/007639A1(EP1533357A1)
[0012] Patent Document 7: JP 2004-276148
[0013] Patent Document 8: JP 2004-333740
DISCLOSURE OF THE INVENTION
Problem to be Solved by the Invention
[0014] The inventor, after a number of various tests and trials,
concluded that it is possible to continue stable coke battery
operation for a long time protecting above-mentioned check valve
from contamination caused by viscous tar mist and said solid
particles suspended in backward flowing gas by providing labyrinth
type partitions installed in the air chamber unit between
above-mentioned check valve and air supply pipe equipped with
impingement type separator.
Means for Solving the Problem
[0015] The present invention is based on the above-mentioned
information. The outline of the invention is as follows. An air
chamber unit having two functions is divided into two sections by
labyrinth partition. One of said two sections contains check valve
unit and the other contains separator that catches and separates
mixture of tar mist and said solid particles. Air intake pipe is
inserted into air chamber unit through bottom plate of said check
valve unit section of air chamber. Spring supported check valve
plate is set horizontally on top end of air intake pipe fitted
vertically. This supporting spring has larger diameter than that of
air intake pipe as to be inserted by air intake pipe. Air supply
pipe is allocated in the opposite side section of said labyrinth
partition. Air supply pipe goes down vertically through bottom
plate of said separator unit section of air chamber. Impingement
type tar mist and said solid particle separator is mounted in the
tail part of air supply pipe. Tar mist and said slid particles
caught by impingement flow down through vertical pipe and never
stay around impingement. To protect check valve plate from
contamination by tar mist and said solid particles completely, an
appropriate resistance against backward gas flowing from inside of
coking chamber is required. For this purpose each labyrinth plate
has an opening at its corner having appropriate gas passage area to
assure complete removal of tar mist and said solid particles. Check
valve plate moves under the delicate balance of its own weight,
supporting force of coil spring and gas pressure fluctuation. Said
check valve plate shall keep its horizontal posture at any moment
during operation. For that purpose at least one guide piece is
provided to keep said check valve plate movement correctly in
vertical direction. Above said check valve plate, a plate is
provided as a stopper against excess jump-up of check valve plate.
Another role of above-mentioned guide piece is to support this
stopper plate. The lower end of coil spring is fixed on said air
chamber bottom plate by a fitting ring. Another ring is fitted to
lower surface of check valve plate to assure perfect contact
between said check valve plate and top end of coil spring. Air
supply pipe is connected to the line pipe that goes into above
mentioned bottom-less combustion space of hollow metallic door
plug. Thus this system composes a coke oven door that gives
additional heat to charged coal particles under controlled
combustion in the bottom-less combustion space of hollow metallic
door plug.
[0016] In addition to the present invention, cylindrical cover
hoods can be added to said air chamber unit. One having diameter
larger than that of said check valve plate can be fitted above said
check valve unit and the other having diameter larger than that of
said air supply pipe can be fitted above tail end of said air
supply pipe. Both hoods provide air/gas stagnant space for each
section of said air chamber unit. Also impingement pieces can be
fitted to inside of air supply pipe.
Effect of the Invention
[0017] The present invention provides a coke oven door equipped
with a system that sends necessary amount of air to burn coke oven
gas that flows through slits of metal shield bars into said hollow
space of said metallic door plug under simple actions and prevents
excess air supply that causes temperature drop in the bottom-less
combustion space and excess oxidation of coke in front of said
hollow metallic door plug. Also the present invention provides very
easy maintenance control for the system. Tar mist and said solid
particles suspended in backward flowing gas from bottom-less
combustion space of hollow metallic door plug caused by sudden
fluctuation of gas pressure do not contaminate check valve plate
because those contaminants are caught by such components as
impingements, labyrinth partition and stagnant spaces provided in
said air chamber unit. Under this condition check valve plate
operates always satisfactorily and sends necessary amount of air to
the bottom-less combustion space and accelerates coking reaction of
coal layer in the vicinity of metallic door plug.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 illustrates a cross-sectional view of a coke oven
door according to this invention taken in the direction of oven
height.
[0019] FIG. 2 illustrates a partially omitted, enlarged perspective
view of air chamber unit. Where air intake pipe, check valve unit,
labyrinth partition and the tail of air supply pipe are shown.
[0020] FIG. 3 illustrates a cross-sectional view of air chamber
unit shown in FIG. 2.
[0021] FIG. 4 illustrates an example of cross-sectional view where,
instead of open tail-end of air supply pipe shown in FIG. 3, a
closed-end cup having one or more air intake holes on side wall are
provided.
[0022] FIG. 5 illustrates another example of cross-sectional view
where, in addition to FIG. 3, a hood is fitted above the tail end
of air supply pipe.
[0023] FIG. 6 illustrates another example of cross-sectional view
where, in addition to FIG. 4, a hood is fitted above the closed-end
of air supply cup.
[0024] FIG. 7 illustrates another example of cross-sectional view
where, in addition to FIG. 3, impingement pieces are added in the
air supply pipe.
[0025] FIG. 8 illustrates another example of cross-sectional view
where, in addition to FIG. 4, impingement pieces are added in the
air supply cup.
[0026] FIG. 9 illustrates another example of cross-sectional view
where, in addition to FIG. 5, impingement pieces are added in the
air supply pipe.
[0027] FIG. 10 illustrates another example of cross-sectional view
where, in addition to FIG. 6, impingement pieces are added in the
air supply cup.
BEST MODE FOR CARRYING OUT THE INVENTION
[0028] Details of this invention will be described by reference to
the drawings. FIG. 1 is a cross-sectional view in the vicinity of
coke oven opening of coke delivery or pushing side illustrating an
embodiment of this invention in the direction of oven height. In
FIG. 1 reference numeral 1 designates a coke oven, 2 coal particles
charged in the coke oven 1. On both sides of coke oven 1 combustion
chambers (not shown) are located. They give heat through heating
wall to coke oven 1 to produce coke.
[0029] Reference numeral 3 is an oven door structure that opens and
closes an opening 4 of coke oven 1. The oven door structure 3
comprises a sturdy cast iron or steel frame 5, slide plate 6 on
coke oven side of frame 5, flanges with knife-edge cross section 7
that contact to door jamb 8, seal plate 9 made of heat-resistant
metal plate that works as a gas sealing member in conjunction with
flanges 7, inner plate 10, heat-insulation box 12 filled with
insulating material 11 such as alumina silicate, isolate, ceramic
fiber and other conventional insulating materials and bottom-less
combustion space 13 in the metallic door plug that projects into
the opening 4 of coke oven.
[0030] Bottom-less combustion space 13 is so structured as to let
coke oven gas generated from coal particles 2 charged in coke oven
4 flow easily into the bottom-less combustion space 13. Horizontal
brackets 14 made of heat resistant steel mounted on heat-insulation
box in such a manner as to partition the box into several spaces
one on top of another. Shield bars 15 made of heat resistant steel
are mounted on bracket 14 horizontally or vertically facing to the
coke oven 1 and to coke oven heating walls on both sides having
narrow slits or holes 16 to provide gas passage way for coke oven
gas to flow into bottom-less combustion space 13 of the hollow
metallic door plug structured as to be easily disassembled and
reassembled. For horizontal shield bars, two types are acceptable.
One has U-shaped plan view and the other has round-cornered
quadrangular plain view. Both types have louver type vertical cross
section providing louver plate sloping from inside edge facing to
said bottom-less combustion space 13 down to front edge facing to
charged coal particles 2 and to said coke oven heating walls on
both sides.
[0031] Front edge of said shield bars are stacked up horizontally
providing horizontal gas inlet slit between each bar. In this
invention, required structure for bottom-less combustion space 13
in the hollow metallic door plug is to let gas generated in coke
oven 1 flow into the bottom-less combustion space 13 of hollow
metallic door plug. There is no limitation for structural design of
hollow metallic door plug.
[0032] Reference numeral 17 is air chamber unit for controlling
supply air to burn coke oven gas flowing into the bottom-less
combustion space 13 of hollow metallic plug. Air chamber unit 17 is
fitted to coke oven door 3 and the air supply pipe 44 is connected
to the combustion nozzle 45 located in the bottom-less combustion
space 13 of hollow metallic door plug. Air chamber unit 17 is a
device to suck and send necessary amount of air to burn coke oven
gas flowing into the bottom-less combustion space 13 of the hollow
metallic door plug. Detail structure of air chamber 17 is as
follows. Air chamber unit 17 is fitted to coke oven door 3. At
least one air chamber unit shall be provided for different levels
over the length of coke oven door. Reference numeral 18 denotes a
latching device that strongly presses and fastens coke oven door 3
to the coke oven opening 4. Latching device 18 comprises
compression springs, latching bar and fittings such as bolts and
nuts and other fastening members. Coke oven door 3 is equipped with
spring-loaded plungers 19 that freely move to and back to press
flange members 7 engaged to seal-plate 9 against door jamb 8 to
make tight sealing of coke oven opening 4. In this invention coke
oven door 3 has two functions such as to open and close job of coke
oven opening 4 and to burn coke oven gas that flows into the
bottom-less combustion space 13 of hollow metallic door plug.
[0033] Each of FIGS. 2 and 3 shows example of air chamber unit 17
illustrated in FIG. 1 by a partially omitted enlarged perspective
view and an enlarged cross-sectional view of this invention.
Reference numeral 17 is air chamber unit. Air chamber unit 17 is an
air-tight vessel comprises bottom plate 21, top plate 22 and side
wall plate 23 that makes voluntarily selected shape such as box,
cylinder and others. Air chamber 20 is structured to suck and
supply a volume of air necessary to burn coke oven gas flowing into
bottom-less combustion space 13 of hollow metallic door plug.
[0034] Air chamber unit 17 is divided into two parts, section (A)
and section (B), by gas passage guide unit 24 as a partition placed
in a voluntarily selected position. In section (A) air intake pipe
27 is fitted. The lower end of air intake pipe 27 is the air
entrance 25. Top end of intake pipe 27 having horizontal edge 26 is
the delivery end for sucked air. In section (B) air supply pipe 30
is fitted. Lower portion of air supply pipe 30 is the air delivery
end 28 and upper portion is air suction end 29. In FIG. 4 an air
supply cup 32 having at least one air intake hole 31 is provided
instead of air supply pipe 30. Cup 32 is mounted in up side down
position. Air supply pipe goes down through the bottom plate 21 of
air chamber unit 17.
[0035] When gas pressure in the bottom-less combustion space 13 in
hollow metallic plug is positive, gas passage guide unit 24 reduces
the pressure and velocity of gas flowing back to air intake pipe 27
via air supply pipe 30 or air delivery cup 32 in the air chamber
unit 17 to clean backward flowing gas by catching and separating
tar mist and said solid particles suspended in the gas. Gas passage
guide unit 24 comprises, the guide plate 33 having a length shorter
than distance between top plate 22 and bottom plate 21 of said air
chamber unit 17 fixed on the bottom plate 21 or top plate 22 of
said air chamber unit 17. When said gas passage guide unit 24
comprises at least two plates, each of said guide plate 33
providing opening at its corner as a gas flowing path 34 is fixed
alternately to the top plate 22 or bottom plate 21 of air chamber
unit 17. Guide plate 33 may have such cross section as flat,
curved, waved or combination of such cross sections. Gas passage
guide unit 24 is so formed as to let backward gas flow meanderingly
into air chamber space 20 through guide plates 33.
[0036] In order to control the flow rate of air being supplied to
bottom-less combustion space 13 of hollow metallic door plug, a
check valve plate 35 is placed above the delivery end 26 of air
intake pipe 27. Check valve plate 35 is kept in a floating position
by a coil spring 36 having a diameter larger than that of air inlet
pipe 27. Above check valve plate 35, a plate 37 is provided to
assure the movement of check valve plate 35 within a limited range.
Plate 37 is mounted on top of guide piece 38 standing on the ring
bracket 39 fitted on middle portion of air intake pipe 27 or on the
bottom plate of air chamber unit 17. Thus inside pressure of air
chamber space 20 of this invention becomes positive when the gas
pressure in bottom-less combustion space 13 becomes positive
because of flow-in of coke oven gas into hollow metallic door plug.
In the event of positive pressure in air chamber space 20, check
valve plate 35 comes down pressing coil spring 36 down to the
position to close the delivery end 26 of air intake pipe 27. On the
other hand, when gas pressure in said bottom-less combustion space
13 becomes negative, pressure in said air chamber space 20 also
becomes negative making check valve plate 35 float upward by the
force of coil spring 36 and open the delivery end 26 of air intake
pipe 27 to let air go into said air chamber space 20.
[0037] In the present invention, ring 40 is fitted to lower surface
of check valve plate 35 keeping the relative position between check
valve plate 35 and the head of coil spring 36 within a preferred
range. Ring 41 is fitted on the ring bracket 39 to keep the bottom
end of coil spring 36 within a preferred position.
[0038] Role of ring 40 and 41 is to keep check valve plate 35 in
correct position always when the valve plate sits on the delivery
end 26 of air intake pipe 27 during frequent vertical up and down
movement of check valve plate 35. Rings 40 and 41 are required to
keep the center of check valve plate 35 and the center of delivery
end of air intake pipe 27 coincident with each other all through
the operation. Ring 41 fixes the bottom of coil spring 36 in a
selected position and does never allow any position change to the
radial direction during operation.
[0039] To assure the smooth movement of check valve plate 35, it is
acceptable to use such materials for said valve plate as glass,
metal, plastics and mica. Among those materials, glass is superior
to others because of its flatness and strength against temperature
change and chemical attack. Glass is better than other
materials.
[0040] Coil spring 36 helps check valve plate 35 float when air
enters into air chamber space 20 and softens the contact shock when
the check valve plate 35 comes to closed position. Elasticity of
coil spring 36 shall meet above-mentioned requirements.
[0041] Stopper plate 37 mounted on top of check valve plate guide
pieces 38 has a role to prevent excess jump-up of check valve plate
35. Possible shapes for stopper plate 37 are disk, ring, ribbon and
others. At least one guide piece 38 for check valve plate shall be
so positioned giving appropriate gap between guide piece surface
and periphery of check valve plate 35 as not to interrupt the
movement of check valve plate 35. Said guide piece 38 shall be so
arranged surrounding coil spring 36 as to make air flow freely into
said air chamber space 20.
[0042] To rectify the flow of air delivered from the end 26 of air
intake pipe 27, a plate 42 is fitted cylindrically to exterior of
said guide piece 38. The upper end of plate 42 may either have a
gap between stopper plate 37 or be fixed to stopper plate 37
forming a cover-hood.
[0043] Air chamber unit 17 is connected to air supply nozzle 45
located in bottom-less combustion space 13 of the hollow metallic
plug via stop valve 43 connected to the delivery end of air supply
pipe 28 illustrated in FIG. 3 or delivery end of air supply cup 32
illustrated in FIG. 4 or air supply line 44 illustrated in FIG. 1.
In the present invention, when clogging or damage happens in air
chamber unit 17 or connected pipe line, it is convenient to make
maintenance work, disassembling or parts exchanging, easy by
adapting screw joint fabrication method. Stop valve 43 fitted on
air delivery end of air chamber unit 17 is useful when it is
necessary to stop air supply to any of individual ovens. The type
of air delivery nozzle located in bottom-less combustion space 13
is not to be specialized. Simple pipe, multi-nozzle type and others
are acceptable.
[0044] Coke oven door having heating function presented in the
present invention is operated in a same manner to that of existing
coke oven doors. In earlier stage of coking of coal particles 2, a
large amount of gas is generated in coke oven 1 and delivered to
dry-main (not shown) through ascension pipe (not shown) and a part
of this gas flows into bottom-less combustion space 13 of hollow
metallic plug and raise gas pressure in the hollow metallic door
plug up to a certain positive level. Gas pressure in air chamber
unit 17 is raised up to positive level in accordance to the gas
pressure in combustion space 13. During this period, check valve
plate 35 comes down because of the positive pressure in the air
chamber unit 17 to the edge of delivery end 26 of air intake pipe
27 and isolate air chamber space 20 from open air. Gas pressure in
coke oven becomes lower gradually along with the progress of coking
reaction because of decrease of gas generation and becomes close to
atmospheric pressure at around middle of coking cycle. However, a
considerable wide ranged and frequent fluctuation of gas pressure
between positive and negative within a very short time continues
during all period of coking cycle therethrough. The reason of this
fluctuation is not clear at the moment. The inventor estimates that
the gas pressure in each oven may be affected by the operation of
other ovens directly because all ovens are connected by gas
collecting-main (not shown). Every time when gas pressure in said
bottom-less combustion space 13 of hollow metallic door plug
becomes negative, gas pressure in air chamber space 20 also becomes
negative. And check valve plate 35 is sucked upward and floated. A
volume of air flows into air chamber space 20 corresponding to the
time when check valve plate 35 is kept floating and burns coke oven
gas in said bottom-less combustion space 13 of hollow metallic door
plug. When gas pressure in bottom-less combustion space 13 of
hollow metallic door plug becomes positive, gas pressure in air
chamber space 20 also becomes positive and check valve plate 35
comes down and closes delivery end 26 of air intake pipe 27 and
prevents flow-out of raw coke oven gas generated in coke oven 1
into open air. Raw coke oven gas flowing into air chamber space 20
through air supply pipe 30 or air delivery cup 32 fitted instead of
air supply pipe 30 is cleaned by gas velocity slow down effect and
labyrinth effect of partition 24. A part of removed mist and
particles suspended in the raw coke oven gas that flows into the
air chamber space 20 falls down in air delivery cup 32 or on the
bottom plate of section (B) of air chamber space 20. Accordingly
check valve plate 35 in the section (A) of air chamber space 20
separated by partition 24 is kept free from contamination by
suspended contaminant particles in the raw coke oven gas and can
continue stable supply of air necessary to burn coke oven gas that
flows into bottom-less gas combustion space 13 in hollow metallic
door plug for long time.
[0045] FIGS. 5 and 6 illustrate other examples of air chamber unit
17 to control air supply to burn coke oven gas in bottom-less
combustion space 13 of hollow metallic plug. FIGS. 5 and 6
illustrate a hood 46 having appropriate diameter installed in
section (B) to provide gas stagnant space (S) above air inlet end
29 of air supply pipe 30 or air delivery cup 32 provided by at
least one air inlet hole 31. In the event of sudden rise of gas
pressure in bottom-less combustion space 13 in hollow metallic door
plug, high velocity flowing back of raw coke oven gas to air
chamber unit 17 may occur. Gas stagnant space (S) in section (B)
catches and removes tar mist and solids, coal and/or coke
particles, suspended in the back flowing gas in front of partition
24. This function contributes to protect check valve plate 35 and
surrounding units from contamination by such contaminants as tar
mist and said solid particles, and assures stable air supply to
burn coke oven gas that flows into bottom-less combustion space 13
of hollow metallic door plug and to reduce the generation of tar
residual adhered around foot of coke oven door 3 effectively.
[0046] FIGS. 7, 8, 9 and 10 illustrate other examples of air
chamber unit 17 equipped with impingement unit 47 mounted in air
supply pipe 30 or air delivery cup 32 illustrated in FIGS. 2 to 6.
Impingement unit 47 reduces velocity of gas flowing backward to air
chamber unit 17 through gas supply pipe 30 or air supply cup 32 in
the event of sudden rise of gas pressure in said bottom-less
combustion space 13 of hollow metallic door plug and catches and
separates tar mist and said solid particles suspended in backward
flowing gas. The cleaned gas remained in room (A) and (B) is sent
back to said bottom-less combustion space 13 in next air supply
chance. Although the shape and structure of impingement vanes or
pieces are not specified, as illustrated in FIGS. 7, 8, 9 and 10,
for example, spiral shaped vanes are mounted on the shaft 48
comprising impingement unit fixed, for example, directly to the top
plate 22 of air chamber unit 17 or to the bottom of air delivery
cup 32 placed in up side down position or by other means of
supporting unit. Said vanes or pieces in various shapes such as
flat, spiral, inclined or others are acceptable to be mounted on
inner surface of air supply pipe 30 or inner surface of air
delivery cup 32 also. In conclusion, backward flowing raw coke oven
gas from coke oven 1 through bottom-less combustion space 13 to the
air chamber unit 17 impinges on impingement vanes or pieces
existing in air supply pipe 30 or air delivery cup 32 while going
through those flow route and decreases its velocity and loses a
large part of such suspended contaminants as tar mist and said
solid particles. Remaining suspended contaminants are removed when
the gas goes through labyrinth partition unit 24. Accordingly, the
air space 20 of room (A) and check valve plate 35 in the air
chamber unit 17 are protected by labyrinth partition unit 24 from
contamination by tar mist and said solid particles suspended in
backward flowing raw coke oven gas assuring long lasting stable
supply of air necessary to burn coke oven gas flowing into
bottom-less combustion space 13 of hollow metallic door plug.
[0047] In the present invention, comparison FIG. 3, for example,
with FIGS. 7 and 8, makes it obvious that said coke oven operation
does not change even when there are partial differences in the
inside structure of air chamber unit 17. Labyrinth partition 24 and
impingement unit 47 remove suspended tar mist and said solid
particles in the backward flowing gas and assure long lasting
stable air supply to burn raw coke oven gas flowing into
bottom-less combustion space 13 of hollow metallic plug suppressing
tar generation and adhesion around the foot of coke oven door.
[0048] Coke oven door providing heating function having bottom-less
combustion space 13 provided on coking chamber side of coke oven
door and air chamber unit 17 mounted on outside of coke oven door
frame 5 raises temperature of coal particles charged in the
vicinity of coke oven door plug by high sensible heat and
combustion heat of raw coke oven gas flowing into combustion space
13 of hollow metallic plug and, as a result, reduces the generation
of poor quality coke remarkably and, in other words, improves the
yield of good quality blast furnace coke. In addition, tar adhesion
to the foot of coke oven door generated under lower temperature
range in early stage of coking process disappears because of heat
generated by burning raw coke oven gas in the combustion space 13,
and, as a result, tar-cleaning operation for coke oven door in
every coke pushing operation is not required anymore. Heat supply
from door plug side raises the mechanical strength of coke produced
in the vicinity of door plug and reduces coke cake collapsing
during pushing operation and minimizes the damage of coke oven
heating wall. By applying the present invention to the existing
coke batteries, their lives are prolonged. The practical
application of the present invention for existing coke batteries
has already started in Japan. It is predicted that application of
the present invention for both existing and newly constructed
batteries will increase in the near future as an effective measure
for not only economical but also environmental purposes.
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