Technical Field
'The present invention relates to a blast furnace
installation.
5 Background Art
Blast furnace installations are designed to be
ca~ab'leo f manufacturing pig iron from iron ore by
charging rawmaterials such as iron ore, limestone, and
coal into the blast furnace main unit through the top
10 and blowing hot air and pulverized coal (PC1 coal) as
auxiliary fuel through the tuyeres on the lower lateral
side.
C i t a t i o n L i s t
Patent L i t e r a t u r e s
15 P a t e n t L i t e r a t u r e 1 : Sapanese P a t e n t Application
Publication No. Hei 10-060508
Patent Literature 2: Japanese Patent Application
Publication No. Hei 11-092809
Summary of Invention
20 Technical Problem
The PC1 coal to be blown into the blast furnace
main unit as auxiliary fuel is required to have high
combustibility because if unburned carbon is generated,
the unburned carbon may possibly obstruct the flow of
25 COmbUSted gas. k'or thls reason, anthracite, bituminous
coal, and the like, which are high quality and expensive,
have been used, thereby increasing the manufacturing
cost of pig iron.
I n view of t h e above, an o b j e c t of t h e p r e s e n t
i n v e n t i o n i s t o p r o v i d e a b l a s t f u r n a c e i n s t a l l a t i o n
c a p a b l e of r e d u c i n g t h e m a n u f a c t u r i n g c o s t of p i g i r o n .
Solution to Problem
5 A b l a s t f u r n a c e i n s t a l l a t i o n a c c o r d i n g t o a f i r s t
a s p e c t o f t h e i n v e n t i o n f o r s o l v i n g t h e a b o v e - m e n t i o n e d
problem i s a b l a s t f u r n a c e i n s t a l l a t i o n i n c l u d i n g a
b l a s t f u r n a c e main u n i t , raw m a t e r i a l c h a r g i n g means
f o r c h a r g i n g a raw m a t e r i a l i n t o t h e b l a s t f u r n a c e main
10 u n i t from a t o p t h e r e o f , h o t a i r blowing means f o r
blowing h o t a i r i n t o t h e b l a s t f u r n a c e main u n i t from
a t u y e r e t h e r e o f , and p u l v e r i z e d c o a l f e e d i n g means f o r
f e e d i n g p u l v e r i z e d c o a l i n t o t h e b l a s t f u r n a c e main
u n i t from t h e t u y e r e , c h a r a c t e r i z e d i n t h a t t h e
15 p u l v e r i z e d . c o a l f e e d i n g means i n c l u d e s m o i s t u r e
removingmeans f o r v a p o r i z i n g r n o i s t u r e in low-rank c o a l ,
p y r o l y s i s means f o r p e r f o r m i n g p y r o l y s i s on t h e c o a l
f r o m w h i c h t h e m o i s t u r e i s removed by t h e m o i s t u r e
r e m o v i n g m e a n s , c o o l i n g means f o r c o o l i n g t h e c o a l on
20 which t h e p y r o l y s i s i s p e r f o r m e d b y t h e p y r o l y s i s means,
p u l v e r i z i n g means f o r p u l v e r i z i n g t h e c o a l c o o l e d by
t h e c o o l l n g means, a s t o r a g e t a n k c o n f i g u r e d t o s t o r e
t h e c o a l p u l v e r i z e d by t h e p u l v e r i z i n g means,
t r a n s f e r r i n g means f o r transferring t h e c o a l
25 p u l v e r i z e d by the p u l v e r i z i n g means i n t o t h e s t o r a g e
L a l ~ k w i l l - I a a t ~ e d i iu ~L i ~ ~yed a ,~ d1t1d d e l i v e ~ i l l yi ~ ~ e d l - ~ a
f o r d e l i v e r i n g t h e c o a l i n t h e s t o r a g e t a n k i n t o t h e
hot a i r that is b e i n g blown i n t o t h e b l a s t f u r n a c e m a i n
u n i t .
A b l a s t f u r n a c e i n s t a l l a t i o n a c c o r d i n g t o a s e c o n d
a s p e c t of t h e i n v e n t i o n i s t h e f i r s t a s p e c t o f t h e
i n v e n t i o n , c h a r a c t e r i z e d i n t h a t t h e p y r o l y s i s means
h e a t s t h e c o a l a t a t e m p e r a t u r e between 400 and 6 0 0 ° C .
5 A b l a s t f u r n a c e i n s t a l l a t i o n a c c o r d i n g t o a t h i r d
aspect of t h e invention is the first or second aspect
of t h e i n v e n t i o n , c h a r a c t e r i z e d i n t h a t t h e c o o l i n g
means cools t h e coal to 2 0 0 ° c or below in an inert ga3
a t m o s p h e r e .
10 Ablastfurnaceinstallationaccording t o a f o u r t h
a s p e c t of t h e i n v e n t i o n i s any one o f t h e f i r s t t o t h i r d
a s p e c t s of t h e i n v e n t i o n , c h a r a c t e r i z e d i n t h a t he
p u l v e r i z i n g means p u l v e r i z e s t h e c o a l t o a d i a m e t e r of
1 0 0 prn o r s m a l l e r i n an i n e r t gas a t m o s p h e r e .
15 A blast furnace installation according t n a fifth
a s p e c t o f t h e i n v e n t i o n i s a n y o n e o f t h e f i r s t t o f o u r t h
a a p e c t s of t h e tna~nyion, c h a r a r t e r i 7 . e d i n that t h e
low-rankcoal is any one o f s u b b i t u m i n o u s c o a l andbrown
c o a l .
20 A b l a s t f u r n a c e i n s t a l l a t i o n a c c o r d i n g t o a s i x t h
a s p e c t of t h e i n v e n t i o n i s any one of t h e f i r s t t o f i f t h
a s p e c t s of t h e i n v e n t i o n , c h a r a c t e r i z e d i n t h a t t h e
p u l v e r i z e d c o a l h a s an oxygen atom c o n t e n t r a t i o ( d r y
b a s e ) between 1 0 and 20% by w e i g h t and h a s an a v e r a g e
25 p o r e s i z e between 1 0 and 50 nm.
Advantageous E f f e c t s of I n v e n t i o n
A c c o r d i n g t o t h e b l a s t f u r n a c e i n s t a l l a t i o n s
a c c o r d i n g t o t h e p r e s e n t i n v e n t i o n , it i s p o s s i b l e t o
impart high combustibility to inexpensive low-rank
coal and use it as PC1 coal by drying and pyrolyzing
the low-rank coal to obtain pyrolysis coal high in
reaction activity with oxygen, cooling and pulverizing
5 the pyrolysis coal, and transferring it with a stream
of nitrogengas, andstoringitinsidethe storage tank.
Accordingly, the manufacturing cost of pig iron can be
reduced. In addition, since the pyrolysis coal and the
pulverized coal to which the high combustibility is
10 imparted can be used after they are stored and
transported only for a short period of time, instead
of being stored and transported for a long period of
time, high safety can be secured easily.
Brief Description of Drawings
15 Fig. 1 is a schematic configuration diagram of a
chief part of a main embodiment of a blast furnace
installation according to the present invention.
Fig. 2 is a flowchart showing a procedure for
manufacturing preferred pulverized coal to be utilized
20 in the blast furnace installation according to the
present invention.
Fig. 3 is a flowchart showing a procedure for
manufacturing another preferred pulverized coal to be
utilized in the blast furnace installation according
25 to the present invention.
Description of Embodiment
An embodiment of a blast furnace installation
dccordirig to tlle present invention w i l l be described
with reference to the drawings. However, the blast
furnace installation according to the present
invention is not limited only to the embodiment to be
described below with reference to the drawings.
A main embodiment of the blast furnace
installation according to the present invention will
be described with reference to Fig. 1.
As shown in Fig. 1, a predetermined-amount raw
10 material feed device 111 configured to feed
p l r a d e t e r m i n e d amounts of r a w m a t e r i a l s 1 s u c h as i r o n
ore, limestone, andcoal communicates withthe upstream
side of a charge c o n v e y e r 1 1 2 i n i t s t r a n s f e r d i x e c t i o n ,
the charge conveyer 112 being configured to transfer
15 t h e raw m a t e r i a l s 1. The d o ~ ~ n s t r e asmid e of this charge
conveyer 112 communicates with the upper side of a
furnace t o p hopper 113 at the t o p of a blast furnace
main unit 110. A hot air delivery device 114 configured
to deliver hot air 101 (1000 to 1300'~) communicates
20 withablowpipe 115 provided at eachtuyere ofthe blast
furnace main unit 110.
Note that in this embodiment, the
predetermined-amount raw material feed device 111, the
charge conveyer 112, the furnace top hopper 113, etc.
25 serve as raw material charging means, and the hot air
delivery device 114, the blow pipe 115, etc. serve as
hot air blowing means.
Meanwhile, in the vicinity of the blast furnace
main unit 110, a steam tube dryer type drying device
6
122 i s a r r a n g e d which i s c o n f i g u r e d t o v a p o r i z e
m o i s t u r e 3 i n l o w - r a n k c o a l 2 s u c h a s subbituminous c o a l
o r brown c o a l . N i t r o g e n g a s 102 a s i n e r t gas i s f e d i n t o
t h e d r y i n g d e v i c e 122 from a n i t r o g e n gas f e e d s o u r c e
5 1 2 1 s e r v i n g a s i n e r t gas f e e d i n g means, and water vapor
103 as a h e a t i n g m e d i u m i s f e d i n t o a c o i l - s h a p e d h e a t i n g
p i p e a r r a n g e d i n a c e n t e r p o r t i o n of t h e d r y i n g d e v i c e
1 2 2 . I n t h i s way, t h e d r y i n g d e v i c e 122 can c r e a t e a
low oxygen atmosphere ( a b o u t s e v e r a l % ) i n s i d e a n d h e a t
10 t h e low-rank c o a l 2 f e d from a hopper 122a ( a t 1 0 0 t o
2 0 0 ° C ) t o remove t h e m o i s t u r e 3 and v o l a t i l e components
4 which v o l a t i l i z e a t r e l a t i v e l y low t e m p e r a t u r e s from
the low-rankcoal2, s o t h a t d r i e d c o a l 5 i s k 1 a n u f a c t u r e d ~
A t t h e same t i m e , t h e d r y i n g d e v i c e 1 2 2 can d i s c h a r g e
15 t h e m o i s t u r e 3 and t h e v o l a t i l e components 4 t o t h e
o u t s i d e t o g e t h e r with t h e n i t r o g e n g a s 102.
A d i s c h a r g e p o r t of t h e d r y i n g d e v i c e 122 f o r t h e
d r i e d c o a l 5 i s c o n n e c t e d t o t h e upstream s i d e of a
conveyer 1 4 1 i n i t s t r a n s f e r d i r e c t i o n with a r o t a r y
20 v a l v e 131 t h e r e b e t w e e n , t h e conveyer 1 4 1 i n c l u d i n g a
s h i e l d hood c o v e r i n g i t s p e r i p h e r y . The n i t r o g e n gas
102 from t h e n i t r o g e n gas f e e d s o u r c e 121 i s fed t o t h e
i n s i d e of t h e s h i e l d hood of t h e conveyer 1 4 1 , so t h a t
t h e inside of t h e s h i e l d hood of t h e conveyer 1 4 1 i s
25 a n i t r o g e n gas atmosphere.
The downstieanL side of t h e conveyer 1 4 1 i n t h e
t r a n s f e r d i r e c t i o n i s c o n n e c t e d t o a r e c e i v e p o r t of
a rotary kiln type p y r o l y s i s device 1 2 3 for the dried
c o a l 5 w i t h a r o t a r y v a l v e 132 t h e r e b e t w e e n , t h e
30 p y r o l y s i s d e v i c e 1 2 3 b e i n g c o n f i g u r e d to perform
p y r o l y s i s on t h e d r i e d c o a l 5 . The n i t r o g e n g a s 102 is
f e d i n t o t h e p y r o l y s i s d e v i c e 123 from t h e n i t r o g e n g a s
f e e d s o u r c e 1 2 1 , and cornbusted g a s 104 a s a h e a t i n g
medium i s f e d i n t o a j a c k e t f i x e d l y s u p p o r t e d on t h e
5 o u t e r s i d e . I n t h i s way, t h e p y r o l y s i s d e v i c e 123 can
c r e a t e a n i t r o g e n g a s a t m o s p h e r e i n s i d e and h e a t t h e
d r i e d c o a l 5 ( a t 400 t o 600'~) t o remove v o l a t i l e
components 6 w h i c h v o l a t i l i z e a t h i g h t e m p e r a t u r e s from
t h e d r i e d c o a l 5, s o t h a t p y r o l y s i s c o a l 7 i s
10 m a n u f a c t u r e d . A t t h e same t i m e , t h e p y r o l y s i s d e v i c e
123 c a n d i s c h a r g e t h e v o l a t i l e components 6 t o the
o u t s i d e t o g e t h e r w i t h t h e n i t r o g e n g a s 1 0 2 .
A d i s c h a r g e p o r t of t h e p y r o l y s i s d e v i c e 123 f o r
t h e pyrolysis c o a l 7 is c o n n e c t e d t o the u p s t r e a m side
15 o f a c o n v e y e r 1 4 2 i n i t s t r a n s f e r d i r e c t i o n w i t h a r o t a r y
valve 133 t h e r e h e t w e e n , t h e conx.reyer 1 4 2 i n c l u d i n g a
s h i e l d hood c o v e r i n g i t s p e r i p h e r y . The n i t r o g e n g a s
1 0 7 f r o m t h e nitrngpn gas feed so111-r1~7 1 is fed to the
i n s i d e of t h e s h i e l d hood of t h e c o n v e y e r 142, s o t h a t
20 t h e i n s i d e of t h e s h i e l d hood of t h e c o n v e y e r 1 4 2 i s
a n i t r o g e n g a s a t m o s p h e r e .
The downstream s i d e of t h e c o n v e y e r 142 i n t h e
t r a n s f e r d i r e c t i o n i s c o n n e c t e d t o a r e c e i v e p o r t of
a s t e a m t u b e d r y e r t y p e c o o l i n g d e v i c e 124 f o r t h e
25 p y r o l y s i s c o a l 7 w i t h a r o t a r y v a l v e 134 t h e ~ e b e t w e e n ,
t h e c o o l i n g d e v l c e 1 2 4 b e l n g c o n f i g u r e d t o c o o l t h e
p y r o l y s i s c o a l 7 . The n i t r o g e n g a s 1 0 2 is f e d i n t o t h e
c o o l i n g d e v i c e 124 from t h e n i t r o g e n g a s f e e d s o u r c e
1 2 1 , and c o o l i n g w a t e r 1 0 5 a s a c o o l i n g medium i s f e d
30 into a c o i l - s h a p e d c o o l i n g p i p e a r r a n g e d i n a c e n t e r
p o r t i o n o f t h e c o o l i n g d e v i c e 1 2 4 . I n t h i s way, t h e
c o o l i n g d e v i c e 124 can c r e a t e a n i t r o g e n g a s a t m o s p h e r e
i n s i d e a n d c o o l t h e p y r o l y s i s c o a l 7 ( t o 2 0 O " ~ o r b e l o w ) .
A d i s c h a r g e p o r t of the c o o l i n g d e v i c e 1 2 4 f o r the
5 p y r o l y s i s c o a l 7 i s c o n n e c t e d t o t h e u p s t r e a m s i d e of
a c o n v e y e r 1 4 3 In i L s L L ~ I ~ ~d iKi e~~Lt i u 1 w1 i t h d ~ o t a ~ y
v a l v e 135 t h e r e b e t w e e n , t h e c o n v e y e r 1 4 3 i n c l u d i n g a
31-~ieldh vud cuveriny its periphery. The nitroyen gas
1 0 2 from t h e n i t r o g e n g a s f e e d s o u r c e 1 2 1 1s f e d t o t h e
10 inside of the shield hood of the conveyer 1 4 3 , 30 t h a t
t h e i n s i d e of t h e s h i e l d hood of t h e c o n v e y e r 143 i s
a nitrogen gas atmoephere.
The downstream s i d e of t h e c o n v e y e r 143 i n t h e
t r a n s f e r d i r e c t i o n i s c o n n e c t e d t o a r e c e i v e p o r t of
15 a m i l l t y p e p u l v e r i z a t i o n d e v i c e 125 f o r t h e p y r o l y s i s
c o a l 7 w i t h a r o t a r y v a l v e 136 t h e r e b e t w e e n , t h e
p u l v e r i z a t i o n d e v i c e 125 b e i n g c o n f i g u r e d t o p u l v e r i z e
t h e p y r o l y s i s c o a l 7 . The p u l v e r i z a t i o n d e v i c e 125 can
m a i n t a i n a n i t r o g e n g a s a t m o s p h e r e i n s i d e w i t h t h e
20 n i t r o g e n g a s d e l i v e r e d t h e r e i n t o g e t h e r w i t h t h e
p y r o l y s i s c o a l 7 and p u l v e r i z e t h e p y r o l y s i s c o a l 7 t o
o b t a i n p u l v e r i z e d c o a l 8 ( w i t h a d i a m e t e r of 1 0 0 pm or
s m a l l e r ) .
A l o w e r p o r t i o n of t h e p u l v e r i z a t i o n d e v i c e 1 2 5
25 is c o n n e c t e d t o a g i v e n p o i n t on a t r a n s f e r l i n e 1 5 1
e x t e n d i n g from t h e n i t r o g e n g a s f e e d s o u r c e 1 2 1 . The
t r a n s f e r l i n e 1 5 1 i s c o n n e c t e d t o a r e c e i v e p o r t of a
c y c l o n e s e p a r a t o r 152 s e r v i n g a s s e p a r a t i n g means f o r
s e p a r a t i n g t h e p u l v e r i z e d c o a l 8 from a s t r e a m of t h e
30 n i t r o g e n g a s 1 0 2 . A l o w e r p o r t - i o n of t h e c y c l o n e
9
s e p a r a t o r 1 5 2 i s c o n n e c t e d t o t h e u p p e r s i d e of a s t o r a g e
t a n k 153 c o n f i g u r e d t o s t o r e t h e p u l v e r i z e d c o a l 8 . The
s t o r a g e t a n k 153 c a n m a i n t a i n a n i t r o g e n g a s a t m o s p h e r e
i n s i d e .
5 A l o w e r p o r t i o n of t h e s t o r a g e t a n k 153 i s
c o n n e c t e d t o an i n j e c t i o n lance 1 5 4 connected t o t h e
b l o w p i p e 1 1 5 . The p u l v e r i z e d c o a l 8 i n t h e s t o r a g e t a n k
153 can be f e d i n t o thp blrlrrd pip^ 115 Y h r n l ~ r ~ ht h e
i n j e c t i o n l a n c e 154.
10 Note t h a t r e f e r e n c e s i g n l l O a i n F i g . 1 d e n o t e s
a t a p h o l e t h r o u g h which t o t a k e o u t m o l t e n p i g i r o n
( h o t metal) 9 .
I n this emhociiment d n s c r i h e r l above, the nj trngen
gas f e e d s o u r c e 1 2 1 , t h e d r y i n g d e v i c e 122, t h e r o t a r y
15 v a l v e 131, e t c . s e r v e as m o i s t u r e removing means; t h e
n i t r o g e n g a s f e e d s o u r c e 121, t h e p y r o l y s i s d e v i c e 1 2 3 ,
t h e r o t a r y v a l v e s 132 and 1 3 3 , t h e c o n v e y e r 1 4 1 , e t c .
s e r v e a s p y r o l y s i s means; t h e n i t r o g e n g a s f e e d s o u r c e
121, t h e c o o l i n g d e v i c e 124, t h e r o t a r y v a l v e s 134 and
20 135, t h e c o n v e y e r 1 4 2 , e t c . s e r v e a s c o o l i n g means; t h e
n i t r o g e n g a s f e e d s o u r c e 121, t h e p u l v e r i z a t i o n d e v i c e
125, t h e r o t a r y v a l v e 1 3 6 , t h e c o n v e y e r 143, t h e l i k e
s e r v e a s p u l v e r i z i n g means; t h e n i t r o g e n g a s f e e d
s o u r c e 121, t h e t r a n s f e r l i n e 151, t h e c y c l o n e
25 s e p a r a t o r 1 5 2 , e t c . s e r v e as t r a n s f e r r i n g means; and
t h e i n j e c t i o n l a n c e 154 e t c . s e r v e a s d e l i v e r i n g means.
t\Text, Llle U p e L d t i U I l U I d b l d S t I u ~ I l d C e
i n s t a l l a t i o n 100 a c c o r d i n g t o t h i s embodiment w i l l be
described.
A s p r e d e t e r m i n e d amounts of t h e raw m a t e r i a l s 1
are f e d f r o m t h e predetermined-amount rawmaterialfeed
d e v i c e 111, t h e raw m a t e r i a l s 1 a r e fed i n t o t h e f u r n a c e
t o p hopper 113 by t h e c h a r g e c o n v e y e r 1 1 2 and c h a r g e d
5 i n t o t h e b l a s t f u r n a c e main u n i t 1 1 0 .
o n r h e o t h e r hand, t h e n i t r o g e n gas 1 0 2 i s f e d from
t h e n i t r o g e n gas f e e d s o u r c e 1 2 1 , a n d t h e low-rank c o a l
2 i s fed i n t o t h e drying d e v i c e 1 2 2 from 'the hopper 1 2 2 a
o f t h e d r y i n g d e v i c e 122. As a r e s u l t , t h e low-rank c o a l
10 2 is heaLed (at 1 0 0 t v 200°C) in a low uxyyerl a t m u s p h e r e
( a b o u t s e v e r a l % ) by t h e w a t e r vapor 103 t h r o u g h t h e
heating p i p e , so that the moisture 3 and the volatile
components 4 v a p o r i z e and a r e d i s c h a r g e d t o t h e o u t s i d e
of the system t o g e t h c r w i t h t h e n i t r o g e n g a s 1 0 2 .
15 A c c o r d i n g l y , t h e low-rank c o a l 2 i s d r i e d and becomes
d r i e d coal 5 .
Note t h a t t h e n i t r o g e n g a s 102 c o n t a i n i n g t h e
v o l a t i l e components 4 u n d e r g o e s combustion t r e a t m e n t
i n a c o m b u s t i o n f u r n a c e n o t shown and is u t i l i z e d a s
20 t h e combusted gas 104, and t h e r e a f t e r u n d e r g o e s
p u r i f i c a t i o n t r e a t m e n t .
The d r i e d c o a l 5 i s d e l i v e r e d o n t o t h e c o n v e y e r
1 4 1 t h r o u g h t h e r o t a r y v a l v e 131, t r a n s f e r r e d t h r o u g h
a n i t r o g e n g a s a t m o s p h e r e , fed i n t o t h e p y r o l y s i s
25 d e v i c e 123 t h r o u g h t h e r o t a r y v a l v e 1 3 2 , and h e a t e d ( a t
400 t o 6 0 0 ° C ) i n a n i t r o g e n gas a t m o s p h e r e by t h e
combusted g a s 1 0 4 t h r o u g h t h e h e a t i n g p i p e , s o t h a t t h e
v o l a t i l e components 6 v a p o r i z e and a r e d i s c h a r g e d t o
t h e o u t s i d e of t h e s y s t e m t o g e t h e r w i t h t h e n i t r o g e n
30 g a s 1 0 2 . As a result, the d r i e d coal 5 u n d e r g o e s
1 I
p y r o l y s i s a n d b e c o m e s p y r o l y s i s c o a l 7 h i g h i n r e a c t i o n
a c t i v i t y w i t h oxygen.
Note t h a t t h e n i t r o g e n g a s 102 c o n t a i n i n g t h e
v o l a t i l e componenis 6 u r ~ d e ~ y u rcso m b u s t i u n treatment
5 i n a c o m b u s t i o n f u r n a c e n o t shown and i s u t i l i z e d a s
t h e cbmbusted gas 104, and t h e r e a f t e r u n d e r g o e s
p u r i f i c a t i o n t r e a t m e n t .
The p y r o l y s i s c o a l 7 i s d e l i v e r e d o n t o t h e
c o n v e y e r 1 4 2 t h r o u g h t h e r o t a r y v a l v e 133, t r a n s f e r r e d
10 t h r o u g h a n i t r o g e n g a s a t m o s p h e r e , f e d i n t o t h e c o o l i n g
d e v i c e 1 2 4 t h r o u g h t h e r o t a r y v a l v e 134, c o o l e d ( t o
2 0 0 ° C o r below) i n a n i t r o g e n g a s a t m o s p h e r e by t h e
c o o l i n g w a t e r 105 t h r o u g h t h e c o o l i n g p i p e , d e l i v e r e d
o n t o t h e c o n v e y e r 143 t h r o u g h t h e r o t a r y v a l v e 135,
15 t r a n s f e r r e d t h r o u g h a n i t r o g e n g a s a t m o s p h e r e , f e d i n t o
t h e p u l v e r i z a t i o n d e v i c e 1 2 5 t h r o u g h t h e r o t a r y v a l v e
136, and p u l v e r i z e d ( t o a d i a m e t e r of 100 pm o r s m a l l e r )
i n a n i t r o g e n g a s a t m o s p h e r e . A s a r e s u l t , t h e p y r o l y s i s
c o a l 7 becomes p u l v e r i z e d c o a l ( P C 1 c o a l ) 8 .
20 The p u l v e r i z e d c o a l (PC1 c o a l ) 8 i s t r a n s f e r r e d
t h r o u q h t h e t r a n s f e r l i n e 151 from t h e p u l v e r i z a t i o n
d e v i c e 125 by t h e s t r e a m o f t h e n i t r o g e n g a s 102 from
t h e n i t r o g e n g a s f e e d s o u r c e 121, and d e l i v e r e d i n t o
t h e c y c l o n e s e p a r a t o r 152 t o be s e p a r a t e d from t h e
25 s t r e a m of t h e n i t r o g e n g a s 1 0 2 . A s a r e s u l t , t h e
p u l v e r i z e d c o a l (PC1 c o a l ) 8 is s t o r e d i n a n i t r o g e n
g a s a t m o s p h e r e i n s i d e t h e s t o r a g e t a n k 1 5 3 .
The p u l v e r i z e d c o a l (PC1 c o a l ) 8 s t o r e d i n t h e
s ~ o r a g et ank 153 i s d e l i v e r e d i n t o t h e blow p i p e 115
through the injection lance 154, and cornbusted as fed
into the hot air 101 delivered into the blow pipe 115
from the hot air delivery device 114. As a result, the
pulverizedcoal (PC1 coal) 8turns intoa flame andforms
5 a raceway at the tip of the blow pipe 115, thereby
burning the coal and the like in the raw materials 1
inside the blast furnace main unit 110. Accordingly,
the iron ore in the raw materials 1 is reduced and taken
out as pig iron (hot metal) 9 from the tap hole 110a.
10 In sum, while conventional blast furnacc
installations use anthracite, bituminous coal, or the
l i l c e , which i~ high quality and cxpcnsivc, as PC1 coal,
the blast furnace installation 100 according to this
embodiment can impart h i g h combustibility to
15 inexpensive low-rank coal 2 such as subbituminous coal
or brown coal and s a f e l y IISE? i t as PCT coal by d r y i n g
and performing pyrolysis the low-rank coal 2 to obtain
pyrolysis coal 7 h i g h i n r e a r . t . i n n a c t - i v i t y w i t h n x y g e n
(the reactivity with oxygen is approximately 20 times
20 greater than that of the low-rank coal 2), coolinq and
pulverizing the pyrolysis coal 7 in a nitrogen gas
atmosphere, transferring it with a stream of nitroqen
gas, and storingit in a nitrogen gas atmosphere inside
the storage tank 153.
2 5 Thus, according tothe blast furnace installation
100 accordingtothls embodiment, lnexpenslve low-rank
coal 2 can be used as the PCI coal 8. Accordingly, the
manufacturing cost of the pig iron 9 can be reduced.
Meanwhile, the pyrolysis coal7 andthe pulverized
30 coal 8 to which the high combustibility is imparted can
13
be u s e d a f t e r t h e y a r e s t o r e d and t r a n s p o r t e d o n l y f o r
a s h o r t p e r i o d of t i m e , i n s t e a d of b e i n g s t o r e d and
t r a n s p o r t e d f o r a l o n g p e r i o d of t i m e . A c c o r d i n g l y ,
h i g h s a f e t y can be s e c u r e d e a s i l y .
5 Here, p u l v e r i z e d c o a l (PC1 c o a l ) 8A w i t h an oxygen
aLon~ coriterlL L - a t i u ( d ~ yba se) of 1 0 to 18%b y w e i g h t
and an a v e r a g e p o r e s i z e of 10 t o 50 nm [ n a n o m e t e r )
( p r e f e r a b l y 2 0 t o 50 nm (nanometer)) i s p r e f e r a b l e .
A s shown i n F i g . 2 , t h e p u l v e r i z e d c o a l (PC1 c o a l )
10 8A as m e n t i o n e d above can be e a s i l y m a n u f a c t u r e d by:
d r y i n g low-rank c o a l ( o x y g e n a t o m c o n t e n t r a t i o ( d r y
b a s e ) : o v e r 18% by w e i g h t , a v e r a g e p o r e s i z e : 3 t o 4
nm) 2 s u c h a s s u b b i t u m i n o u s c o a l o r brown c o a l b y h e a t i n g
it ( a t 110 t o 2 0 0 ° C x 0 . 5 t o 1 h o u r ) i n a Low oxygen
15 a t m o s p h e r e (oxygen c o n c e n t r a t i o n : 5% by volume o r
l o w e r ) t o r e m o v e m o i s t u r e ( d r y i n g s t e p 5 2 1 ) ; p e r f o r m i n g
p y r o l y s i s on t h e r e s u l t a n t c o a l by h e a t i n g it ( a t 460
t o 5 9 0 ° C ( p r e f e r a b l y 500 t o 5 5 0 ° C ) x 0 . 5 t o 1 h o u r ) i n
a low oxygen a t m o s p h e r e (oxygen c o n c e n t r a t i o n : 2% by
20 volume o r l o w e r ) t o remove p r o d u c e d w a t e r , c a r b o n
d i o x i d e , t a r , and t h e l i k e a s p y r o l y s i s g a s and
p y r o l y s i s o i l ( p y r o l y s i s s t e p 512); c o o l i n g t h e
r e s u l t a n t c o a l ( t o 50°C o r below) i n a low oxygen
a t m o s p h e r e (oxygen c o n c e n t r a t i o n : 2% by volume o r
25 l o w e r ) ( c o o l i n g s t e p 513); and pulve~izing t h e
resultant c o a l ( t o a p a r t i c l e s i z e : 77 pm o r s m a l l e r
( 8 0 % p a s s ) ) ( p u l v e r i z i n g s t e p 514).
I n t h e p u l v e r i z e d c o a l ( P C 1 c o a l ) 8A a s m e n t i o n e d
above, t h e a v e r a g e p o r e s i z e i s 1 0 t o 50 nm, t h a t i s ,
30 t a r p r o d u c i n g groups such as o x y g e n - c o n t a i n i n g
14
f u n c t i o n a l g r o u p s ( s u c h a s c a r b o x y l g r o u p s , a l d e h y d e
g r o u p s , e s t e r g r o u p s , and h y d r o x y l g r o u p s ) d e s o r b and
g r e a t l y d e c r e a s e , w h i l e t h e oxygen atom c o n t e n t r a t i o
( d r y b a s e ) i s 10 t o 18% b y w e i g h t , t h a t i s , d e c o m p o s i t i o n
5 ( d e c r e a s e ) of t h e main s k e l e t o n s ( c o m b u s t i o n
components m a i n l y c o n t a i n i n g C , H I and 0) i s g r e a t l y
s u p p r e s s e d . Hence, when t h e p u l v e r i z e d c o a l (PC1 c o a l )
8A i s blown i n t o t h e b l a s t f u r n a c e main u n i t t h r o u g h
t h e t u y e r e t o g e t h e r w i t h h o t a i r , t h e p u l v e r i z e d c o a l
10 ( P C 1 c o a l ) 8A c a n be c o m p l e t e l y cornbusted w i t h a l m o s t
n o u n b u r n e d c a r b o n ( s o o t ) g e n e r a t e d b e c a u s e many oxygen
atoms a r e c o n t a i n e d i n t h e main s k e l e t o n s and a l s o
b e c a u s e t h e l a r g e - s i z e d p o r e s a l l o w t h e oxygen i n t h e
h o t a i r t o be e a s i l y s p r e a d t o t h e i n s i d e and a l s o
15 s i g n i f i c a n t l y s u p p r e s s e s t h e p r o d u c t i o n of t a r .
A c c o r d i n g l y , t h e combustion e f f i c i e n c y can be improved
a t a low c o s t .
Moreover, s i n c e t h e a v e r a g e p o r e s i z e i s n o t
s m a l l e r t h a n 1 0 nm, t h e p u l v e r i z e d c o a l (PC1 c o a l ) 8A
20 can p r e v e n t a s i t u a t i o n where t h e s p r e a d a b i l i t y of t h e
oxygen i n t h e h o t a i r t o t h e i n s i d e i s d e t e r i o r a t e d and
t h e c o m b u s t i b i l i t y i s a c c o r d i n g l y d e t e r i o r a t e d . I n
a d d i t i o n , s i n c e t h e a v e r a g e p o r e s i z e i s 5 0 n m o r s m a l l e r ,
t h e p u l v e r i z e d c o a l ( P C 1 c o a l ) 8A can be p r e v e n t e d from
25 c r a c k i n g i n t o s m a l l e r s i z e s due t o h e a t shock and t h e
l i k e , and can t h e r e f o r e be p r e v e n t e d from c r a c k i n g i n t o
s m a l l e r s i z e s when blown i n t o t h e b l a s t f u r n a c e main
u n i t , whichmakes i t p o s s i b l e t o p r e v e n t t h e p u l v e r i z e d
c o a l (PC1 c o a l ) 8A from p a s s i n g t h r o u g h t h e i n s i d e of
30 t h e b l a s t f u r n a c e m a i n u n i t w i t h t h e gas s t r e a m a n d b e i n g
d i s c h a r g e d w i t h o u t c o m b u s t i o n .
15
F u r t h e r , s i n c e t h e oxygen atom c o n t e n t r a t i o ( d r y
b a s e ) i s n o t s m a l l e r t h a n 10% by w e i g h t , t h e p u l v e r i z e d
c o a l ( P C 1 c o a l ) 8A can be c o m p l e t e l y combusted w i t h o u t
a d d i n g o x i d a n t o r e n r i c h i n g t h e oxygen i n t h e h o t a i r .
5 F u r t h e r m o r e , t h e pore volume of t h e p u l v e r i z e d
c o a l ( P C 1 c o a l ) 8A i s p r e L e r a b l y 0 . 0 5 t o 0 . 5 crn3/cj and
p a r t i c u l a r l y p r e f e r a b l y 0 . 1 t o 0 . 2 cm3/g. This i s
b e c a u s e the s u r L a c e drea oT ~ u i ~ L d c (Ls u ~ . C d c ea ~ e duf
r e a c t i o n ) w i t h t h e oxygen i n t h e h o t a i r w i l l be s m a l l
10 and the c o m b u s t i b i l i t y will possibly be dctcrioratcd
i f t h e p o r e volume i s s m a l l e r than 0 . 0 5 cm3/g, whereas
l a r g e amounts of components will volstilizc and thc
p u l v e r i z e d c o a l (PC1 c o a l ) 8A w i l l be s o p o r o u s t h a t
t h e combustian components may be excessively reduced
15 i f t h e p o r e volume i s l a r g e r t h a n 0 . 5
In a d d i t i o n , t h e s p e c i f i c s u r f a c e area of the
p u l v e r i z e d c o a l (PC1 c o a l ) 8A i s p r e f e r a b l y 1 t o 100
m2/g and p a r t i c u l a r l y p r e f e r a b l y 5 t o 20 m2/g. T h i s i s
b e c a u s e t h e s u r f a c e area of c o n t a c t ( s u r f a c e a r e a of
20 r e a c t i o n ) w i t h t h e oxygen i n t h e h o t a i r w i l l be s m a l l
and t h e c o m b u s t i b i l i t y w i l l p o s s i b l y be d e t e r i o r a t e d
i f t h e s p e c i f i c s u r f a c e a r e a i s s m a l l e r t h a n 1 mL/g,
w h e r e a s l a r g e amounts of components w i l l v o l a t i l i z e and
t h e p u l v e r i z e d c o a l (PC1 c o a l ) 8A w i l l be s o p o r o u s t h a t
25 t h e c o m b u s t i o n components may be e x c e s s i v e l y r e d u c e d
iC t h e s p e c l r l c s u r t a c e area 1s l a r g e r t h a n I O U m2/g.
Moreover, s i n c e t h e t e m p e r a t u r e of t h e p y r o l y s i s
in t h e p y r o l y s i s s t e p S12 i s 460 t o 5 9 0 ° c , t h e t a r
p r o d u c i n g g r o u p s s u c h a s o x y g e n - c o n t a i n i n g f u n c t i o n a l
30 g r o u p s can be d e s o r b e d s u f f i c i e n t l y from t h e low-rank
P 6
coal 2, and the average pore size can easily be 10 to
50 nm. In addition, the decomposition of the main
skeletons (combustion components mainly containing C,
H, and 0) of the low-rank coal 2 can be suppressed, and
5 the reduction of the combustion components due to the
volatilization of large amounts of components can be
suppressed.
F u L L ~ I ~ Lp,u l v e ~ i ~ e~d; i j d l ( P C 1 ~ i i d l )8 B w i t 1 1 ail
oxygen atom content ratio (dry base) of 12 to 20% by
10 weight and an average pure size u f 10 tu 50 nm
(preferably 20 to 50 nm) is more preferable.
As shown in Fig. 3, the pulverized coal (PC1 coal)
8B as mentioned above can be easily manufactured by:
drying the low-rank coal (oxygen atom content ratio
15 (dry base): over 18% by weight) 2 in a similar way to
as described above (drying step S I S . ) ; performing
pyrolysis on the resultant coal in a similar way to as
described above (pyrolysis step 512); cooling the
resultant coal (to 50 to 150°C) in a low oxygen
20 atmosphere (oxygen concentration: 2% by volume or
lower) (cooling step 523); partially oxidizing the
resultant coal by exposing it to an oxygen-containing
atmosphere (oxygen concentration: 5 to 21% by volume)
(at 50 to 150°C x 0.5 to 10 hours) to let the coal
25 chemically adsorb oxygen (partially oxidizing step
S Z 5 ) ; and pulverlzlng the resultant coal ln a slmllar
way to as described above (pulverizing step S14).
In the pulverized coal (PC1 coal) 8B as mentioned
above, like the pulverized coal 8A, the average pore
30 size is 10 to 50 nm, that is, tar producing groups such
17
a s o x y g e n - c o n t a i n i n g f u n c t i o n a l groups ( s u c h a s
c a r b o x y l g r o u p s , a l d e h y d e g r o u p s , e s t e r g r o u p s , and
h y d r o x y l g r o u p s ) d e s o r b a n d g r e a t l y d e c r e a s e , w h i l e t h e
oxygen atom c o n t e n t r a t i o ( d r y b a s e ) i s 1 2 t o 20% by
5 w e i g h t , t h a t i s , decomposition ( d e c r e a s e ) of t h e main
s k e l e t o n s (combustion components mainly c o n t a i n i n g C,
HI and 0) is g r e a t l y s u p p r e s s e d , and more oxygen atoms
have c h e m i c a l l y a d s o r b e d . Hence, when t h e p u l v e r i z e d
c o a l ( P C 1 c o a l ) 8B i s blown i n t o t h e b l a s t f u r n a c e main
10 u n i t t h r o u g h t h e t u y e r e t o g e t h e r w i t h h o t a i r , t h e
p u l v e r i z e d c o a l ( P C 1 c o a l ) 8B can be c o m p l e t e l y
combusted with unburned carbon ( s o o t ) g e n e r a t e d l e s s
t h a n when the p u l v e r i z e d c o a l 8 A i s combusted because
t h e main s k e l e t o n s c o n t a i n s more oxygen atoms t h a n t h e
15 p u l v e r i z e d c o a l 8A and a l s o because t h e l a r g e - s i z e d
p o r e s a l l o w t h e oxygen i n the h o t a i r t o b e e a s i l y s p r e a d
t o t h e i n s i d e and a l s o s i g n i f i c a n t l y s u p p r e s s e s t h e
p r o d u c t i o n of t a r l i k e t h e p u l v e r i z e d c o a l 8A.
A c c o r d i n g l y , t h e combustion e f f i c i e n c y can be improved
20 a t a low c o s t more r e l i a b l y t h a n t h e p u l v e r i z e d c o a l
8A does .
Moreover, l i k e t h e p u l v e r i z e d c o a l 8A, since t h e
a v e r a g e pore s i z e i s n o t s m a l l e r t h a n 10 nm, t h e
p u l v e r i z e d c o a l ( P C 1 c o a l ) 8B can p r e v e n t a s i t u a t i o n
25 where t h e s p r e a d a b i l i t y of t h e oxygen in t h e h o t a i r
t o t h e i n s i d e i s d e t e r i o r a t e d and t h e c o m b u s t i b i l i t y
i s a c c o r d i n g l y d e t e r i o r a t e d . In a d d i t i o n , l i k e t h e
p u l v e r i z e d c o a l 8A, s i n c e t h e a v e r a g e p o r e s i z e i s 50
nm o r s m a l l e r , t h e p u l v e r i z e d c o a l (PC1 c o a l ) 8 B can
30 be p r e v e n t e d from c r a c k i n g i n t o s m a l l e r s i z e s due t o
h e a t s h o c k a n d t h e l i k e , and can t h e r e f o r e be p r e v e n t e d
from c ~ a c k i n g i n t o s m a l l e r s i z e s when blown i n t o t h e
b l a s t f u r n a c e main u n i t , which makes it p o s s i b l e t o
p r e v e n t t h e p u l v e r i z e d c o a l (PC1 c o a l ) 83 from p a s s i n g
t h r o u g h t h e i n s i d e of t h e b l a s t f u r n a c e main u n i t w i t h
5 t h e gas streamandbeingdischargedwithout c o m b u s t i o n .
F u r t l l e r , s i n c e the oxygerl alor~iC O I I L ~ I I L~ d t i u( d r y
b a s e ) i n t h e p u l v e r i z e d c o a l (PC1 c o a l ) 8B i s 20% by
w e i g h t o r l o w e r , i L i s p o s s i b l e Lu y r e v e r i l CI s i L u d t i u r ~
where t h e oxygen c o n t e n t i s e x c e s s i v e l y l a r g e and t h e
10 amount o f heat g e n e r a t i o n is exce33ivcly reduced.
F u r t h e r , l i k e t h e p u l v e r i z e d c o a l 8A, t h e p o r e
volume of t h e p u l v e r i z e d c o a l (PC1 c o a l ) 8B is
p r e f e r a b l y 0 . 0 5 t o 0 . 5 cm3/g and p a r t i c u l a r l y
p r e f e ' r a b l y 0 . 1 t o 0 . 2 cm3/g. T h i s i s b e c a u s e t h e s u r f a c e
15 a r e a of c o n t a c t ( s u r f a c e a r e a of r e a c t i o n ) w i t h t h e
oxygen i n t h e h o t a i r w i l l be s m a l l and t h e
c o m b u s t i b i l i t y w i l l p o s s i b l y be d e t e r i o r a t e d i f t h e
p o r e volume i s s m a l l e r t h a n 0 . 0 5 cm3/g, whereas l a r g e
amounts of components w i l l v o l a t i l i z e and t h e
20 p u l v e r i z e d c o a l (PC1 coal) 8B w i l l be s o p o r o u s t h a t
t h e c o m b u s t i o n components may be e x c e s s i v e l y r e d u c e d
i f t h e p o r e volume i s l a r g e r t h a n 0 . 5 cm3/g.
I n a d d i t i o n , l i k e t h e p u l v e r i z e d c o a l 8 A , t h e
s p e c i f i c s u r f a c e a r e a of t h e p u l v e r i z e d c o a l (PC1 c o a l )
25 8B i s p r e f e r a b l y 1 t o 100 m 2 i q and p a r t i c u l a r l y
p r e f e r a b l y 5 t o 20 m 2 / g . T h i s i s b e c a u s e t h e s u r f a c e
a r e a of c o n t a c t ( s u r f a c e a r e a of r e a c t i o n ) w i t h t h e
oxygen i n t h e h o t a i r w i l l be s m a l l and t h e
c o m b u s t i b i l i t y w i l l p o s s i b l y be d e t e r i o r a t e d i f t h e
30 s p e c i f i c s u r f a c e a r e a i s s m a l l e r t h a n 1 m2/g, whereas
19
large amounts of components will volatilize and the
pulverized coal ( P C 1 coal) 8B will be so porous that
the combustion components may be excessively reduced
if the specific surface area is larger than 100 r n 2 / g .
5 Moreover, since the temperature of the process in
the partially oxidizing step 5 2 5 is 50 to 150°c,
generation of carbonmonoxide and carbon dioxide by the
combustion reaction can be suppressed even in an air
(oxygen concentration: 21% by volume) atmosphere, and
10 also the p a r t i a l oxidation process can advance even in
an atmosphere where the oxygen concentration is about
5% by volume.
In the embodiment described above, the case where
a steam tube dryer type is applied to the drying device
15 122 and the cooling device 124 is described. Note,
however, that a rotary kiln type like the pyrolysis
device 123 can be applied to the drying device and the
cooling device.
Industrial Applicability
2 0 The blast furnace installation according to the
present invention can reduce the manufacturing cost of
pig iron and can therefore be utilized significantly
beneficially in the steel industry.
We C l a i m :
1. A b l a s t f u r n a c e i n s t a l l a t i o n i n c l u d i n g
a b l a s t f u r n a c e main u n i t ,
r a w m a t e r i a l c h a r g i n y means Tur c h a r y i r i y d
5 raw m a t e r i a l i n t o t h e b l a s t f u r n a c e main u n i t from
a top t h e r e o f ,
h o t a i r b l o w i n g means f o r b l o w i n g h o t a i r
i n t o the blast furnace main u n i t from a tuyere
t h e r e o f , and
10 p u l v e r i z e d coal f e e d i n g means £or f e e d i n g
p u l v e r i z e d c o a l i n t o t h e b l a s t f u r n a c e main u n i t
f r o m the tuyere, characterized in t h a t
t h e p u l v e r i z e d c o a l f e e d i n g means i n c l u d e s
m o i s t u r e removing means f o r v a p o r i z i n g
15 m o i s t u r e i n low-rank c o a l ,
p y r o l y s i s means f o r p e r f o r m i n g p y r o l y s i s on
t h e c o a l f r o m w h i c h t h e m o i s t u r e i s removed by t h e
m o i s t u r e removing means,
c o o l i n g means f o r c o o l i n g t h e c o a l on which
2 0 t h e p y r o l y s i s i s p e r f o r m e d by t h e p y r o l y s i s means,
p u l v e r i z i n g means f o r p u l v e r i z i n g t h e c o a l
c o o l e d by t h e c o o l i n g means,
a s t o r a g e t a n k c o n f i g u r e d t o s t o r e t h e c o a l
p u l v e r i z e d by t h e p u l v e r i z i n g means,
2 5 t r a n s f e r r i n g m e a n s f o r t r a n s f e r r i n g t h e c o a l
p u l v e r i z e d by t h e p u l v e r i z i n g means i n t o t h e
s t o r a g e t a n k w i t h a s t r e a m o f i n e r t g a s , and
d e l i v e r i r l y m e d r i s .Cur d e l i v e r i r i g L i ~ ec od1 i i i
t h e s t o r a g e t a n k i n t o t h e h o t a i r t h a t i s b e i n g b l o w n
3 0 i n t o t h e b l a s t f u r n a c e main unit.
2. The blast furnace installation according to claim
1, characterized in that the pyrolysis means heats
the coal at a temperature between 400 and 6 0 0 ° c .
3. The blast furnace installatior1 accos-ding L o claim
5 1 or 2, characterized in that the cooling means
cvuls the coal tu 200'~ ur below in an i n e r t gas
atmosphere.
4. Theblast furnace installation according to anyone
of claims 1 to 3, characterized in that the
10 pulverizingmeans pulverizesthe coal to a diameter
of 100 vrn or smaller i n an inert g a s atmosphere.
5. Theblast furnace installation according to anyone
of claims 1 t o 4, characterizedinthat the low-rank
coal is any one of subbituminous coal and brown
15 coal.
6. The blast furnace installation according to any one
of claims 1 to 5, characterized in that the
pulverized coal has an oxygen atom content ratio
( d r y base) between LO and 20% by weight and has an
20 average pore size between 10 and 50 nm.
Dated t h i s l o t h day of July 2014
w
Aparna Kareer
Of Obhan & Associates
Agent for the Applicant
Patent Agent NO. 1359