close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2404461

код для вставки
“2,404,461
Patented July 23, 1946 '
T UNI-1w
PATENTOFFICB;
‘FURNACES Y
I, Stanleylli. Sanford, ‘Cleveland; chic
" V
‘I
g
NoDrawing.*Application?ctobcr'6,1942;a. .‘
Serial No; 460,979.,
. lClainii
(01; 75541)‘? I
17 "
of
.-~In.th'e production of‘pigiron‘byblastfurnace _ "
areespressedor are inherent in: Table? \
hereinafter. set. ‘forth 'in' this speci?cation :1;
operations; four cardinal factors areri'njvolved,
namely, the'blast, th‘efuehthé charge’: and the
56.5.for: determining the weight. pica/‘ans t‘ .
'
blast per’minute;
.
>
,, ..11 composition of the resultant ‘slag:
inter;
51.0 for ‘determining.the'weight'of ‘carbon in; the
mediate and almost equally important factor;
charge per minute;
'. .
.
'7
1.
.
2
therefmay'be. mentioned that~ the chemical com
31.0 for determining the weight or ironinthe
position of the gases'comingufrom'the top of the
charge per minute;
i:
v
'
furnace‘ isfof‘ importance, as: suclifc'omposition
75.1 for determining the weight: of carbonthat '7
is'an indication of the'actuali performance'of‘ the
will‘ be consumed by the oxygen of the? blast
furnace with'n'respect to the volatilization of all 10
‘the elements which are:volatiliaable.v A consid
' per minute;
1
eration of: standard text‘ books‘and‘ prior art
could lead thegalveragelayman'to "believe that
all. ferrous metallurgy; including. blast furnace
therebyestablishing and,‘ maintaining chemical
balance upon stoichoimetricl;proportioning,, in
which not more than 76' per cent of the total
operations; has ‘been reduce'd'ito' an exact science, v15 weight'ofv carbon in. the charge. is. consumed. by
v the total‘ weight of‘. ‘oxygen ‘in the predetermined
compen-Sated' and‘ that all of] these factors in
blast volume upon the chemical" equivalence ratio
actual performance customarily ‘are ‘dovetailed
of 1.33. pounds of oxygen for each'on‘e pound‘jof ‘
' that all'the'important"factorsinvolved have been
so completely that the entire operation of‘ a blast
furnace is’ wholly‘ standardized on a ‘basis upon 20
which. anyone skilled ‘in the art can duplicate
carbon, thus evidencing-that since, no leacess blast
oxygenlis available, overblowing-of the furnace
is impossible. ,
any‘ furnace performance at will; However; this " ‘’
The empirical factors'565, 51.0, 31.0 set forth
actuallyhas not been the’case, standard opera
‘above arebased upon the fixed blowing. rateof
tions being accompanied by many variations in
65,000 cubic feet of. wind'which'has- been found,
operating conditions in the same furnace, pro 25 in'accordance with the present invention;v to be \
ducing unbalanced’ chemical andv thermal‘ en
the standard-requirement of blast for theipro
vironments, and causing, generally, sub-standard 5 >' duction .of one-'grosseton of pig iron perminute.
yields: which very often fall very substantially
These empirical factors areused as empirical
below‘ even the rated tonnage: of the ‘furnace.
30 divisions of 65,000 cubic feetzlto determine the
The present invention has‘ for'one of its obf
total pounds ‘(per gross ton 'of'pigw iron) of- the
jects- the provision of‘ an improved processor. _
blast furnace operation which obviates the irreg
ularitiesof blast furnace operations which char
acterize the so-called “standard 'practice,”'the 35
present process being distinguished from stand‘
ard practice by proportioning and maintaining
the carbon content of‘ the. charge tothe oxygen
content of" the predetermined blast volume in the
<
carbon in’ the coke, iron in: the metallic mix‘ of
the burden, thus-standardizing all-critical factors
of blast and burden solely upon the blast volume 1
of 65,000 cubic‘ feet per gross ton of iron.‘
Of. the above factors, factor 56.5 is obtained I
by dividing 65,000 cubic feet of blast per minute
byithe' Weight of oxygen. in pounds perminute
in that-blastg‘the'factor 51.0'is obtained by divid
ing‘ cubic feetfofi blast per minute by ‘the pounds
ratio of‘ more than one pound of‘ carbon for each 40
one pound of oxygen‘, proportioning and main- _
of carbon in ‘the charge required per minute to
taining the iron content of"_ the charge to’ the
carbon content of the charge in the ratio of ‘more
‘ '
than. 1.37 pounds but less‘ than 1.82‘ pounds of
unite with the oxygen reaching the tuyeres'; the.
factor 31.0 is obtained’ by dividing 65,0003 cubic
iron to each one pound of1 carbon, proportioning 45 feet of-“bl-ast by 2,100“ pounds of ‘metallic iron
charged per minute; the factor 75.1 is obtained .
and. maintaining the iron content of the charge
by‘ dividing 65,000 cubic feet‘ of ' blast by’v 865
of'more than 1.37 but less than 1.82 pounds of “ pounds of carbon that are required to combine
with’ 1,150pounds of‘ oxygen in the 65,000 cubic
iron to each one pound‘ of oxygeni’iin the predeter
' to the oxygen content'of the blast in the ratio A _
mined blast, such‘ proportidnin-g’ being readily
accomplished‘ by dividing the predetermined blast
50
volume by the following empirical division, all , ,_
feet of blast,
‘
'
'
It is a further objectfto provide a methodjof "
operation which will require‘ a less total weight
2,404,461 .7
4
3 .
of blast than of charge, and a less total weight. I. ring from the variations in the composition of
of oxygen in the blast than of .carbonjin the
charge.
7
I
x
'
-
‘the charge andvcombustion of the coke in the -
charge v(this excess‘blast requiring the addition
of compensating carbon or, alternatively, reduce
ing thejamount of blast being introduced) are
M
It is a still further object to provide a method
of operation whereby the fuel consumption is
lowered and furnace production is increasedi
undesirable conditions which are to be avoided.
‘It is an additionalobject to provide a sta
This condition causes reduced e?iciency, and, in
‘ ' .7 bilized method of operation which‘will prevent
accordance with they present invention thereis
hanging and slipping of the furnace charge and
maintained continuously a chemical balance of
prevent the creationof “hot tops” and/or “cold
bottoms’?
‘
-
.
r
'
'
s
i
10
-‘
the vital components inthe charge and‘ in the
blast. Such a chemical; balance insures maxi
. mum production at minimum 'cost.‘_' "
PRESENT IMPROVED‘ METHOD Foe OPERATING BLAST
I
It is absolutely necessary that this, blast be,
' FURNACES,
heated to a temperature as close as possible to
In“ accordance with the present invention, it
15] 1300” E, in order to provide the indispensable
has been discoveredithat the realtiming element
v‘back-log of sensible heat that is demanded for
continuous operation. Therefore, the prerequi
2 in. blast furnace operation-is the blast-andthat
Vmaximum temperature of the blast is an im
' sites‘ for obtaining, the maximum thermal e?i
perative adjunct of the blast; 1that it is equallyv -.;ciency of a given furnace are: _
'
.
'
_ requisite that the actual percentage of the total 20 I (-1‘) Determining the maximum rate of carbon 1 .
' carbon that actually‘ arrives‘ at the tuyeres, for‘
combustion per. minute, maintained at. the
°°mbusti0n by ‘the oxygen of the blast, be'ehem;
tuyeres, by blowing‘ a constant volume of blast
‘' ically, balanced against the, actual percentage
at maximum temperature.
Weight of the oxygen in the blast; and that,.vvery
'
‘
f! -(2) Charging'only such total weight ofcarbon 7
. de?nitely, no blast volume should be blown for
as'will insure the arrival Eat the tuyéres of‘only
. the combustion at the'tuyeres of the remaining '
the requisite total weight of ‘carbon necessary for
percentage of, the solid carbonin'tthe charge,
the maintenance of ‘such established combustion
because it has been discovered that such remain
ing percentage weight of carbon undergoes “di
-~. (3) ‘Blowing only, per minute, the total volume
rect” combustion in the top half of the‘blast 30 of. superheatedblast, or wind, which contains
furnace,. and, consequently, it never arrives in
the necessary" oxygen to'support the combustion
' the combustion zone at the tuyeres. , Thus, by the
at the tuyéres of, that proportion of the total
present invention, there is eliminated the long ' weight of carbon. x-Excess blowing de?nitely
standing universal custom of ' “over-blowing.”
raises the mantle .in the furnace and ‘thereby
In fact, it has been found that the entire reduction
lowersv the overall: temperature of the hearth,
of iron oxides is accomplished by the process of
because the increased volume of gases, upon leav
the present invention, in the top thirdv of the fur
ing the hearth, carries excessive temperature out
of the hearth where‘ it is needed to maintain the
In practicing the present invention, it is found
indispensable “back-log” for insuring continuous '
that the actual'chemistry and the actual mode of 40 operation, up into the stack where it performsrno
reduction ‘ tend generally towards 100 per cent
useful service.
thermal e?iciency in blast furnace operation only I w
~'I‘he ratio of’ carbon to oxygen, and the ratio of
rate;
vnace.
,
,
-
>
.
\
'
'
.
.
when, insofar as is possible, there is maintained
free oxygen to combined, or reducible, oxygen are
a constant burden ratio and a constant blastv vol-v
vital'factors iniblast furnace operation. In the
45
'ume at maximum temperature,» for any given
foregoing estimates there has :been made the very
grade of pig iron product; and that any ‘necese
best use of these factors for obtaining the maxi
sary thermal‘ adjustments can be made readily n . mum results, wherein the burden ratio would be
by alteration of the blast temperature, which
- ‘ more than 2.25 and the free oxygen to reducible
procedure is in sharp contrast with the long es
oxygen ratio should be less than 1.75;
tablished, ' universal custom’ of variations and 50
In practice it is. found th‘at‘nothing is more
“over-blowings” which characterize the standard
fatal to ‘the-thermal e?iciency of a blast furnace.
practice, and which continue to unstabilize blast ,_~ _. than the long-established and universally used
. furnace operations?
In accordance with the present invention, the
method of“pulling” the'wind and decreasing the
burden ratio every’ time the silicon content in the '
improved results are due‘to the maintenance of 55 iron threatens to exceed the upper limit of the
ratios of essential’ materials in strict chemical
speci?cation, because this condition of itself is a
- equivalence with each other, and because, in the
de?nite indication of the furnace being over
improved process every cardinal factor is estab
blown and that the excess volume of hearth gases
lished permanently upon a chemical balance’ of
are carrying the high temperature of the hearth
.the vital factors O/C/Fe.‘
‘
7
~; ' It is apparent also that the constant'minimum'
required volume of blast at the maximum‘ tem-l
too high in the shaft, thereby inducing the re
duction of silica to silicon at a level in the fur
nace -Which?is considerably above the level at’
which the oxygenof the blast burns ‘the hearth‘
perature would produce the ‘constant minimumi
products of combustion, and, therefore, would
carbon, that being the level'at which the highest
convey the constant minimum volume of tem-f 65 temperature should be con?ned.
perature out of the 'tuyére zone. Conjointly, the
Blast furnaces that are charged ‘and blasted '
constant minimum fuel ratio would insure the
according to the method herein described obviate
constant minimum products of combustion. ' the necessity for frequent manipulation, by rea-v
Therefore, there is the necessity for the constant
son of their ability to'adjust themselvesautomat- '
minimum required blast = volume at maximum, 70 .ically to changingcon'ditions within,- The fol-7
temperature and the constant maximum burden
lowing tables show a, comparison of the results
ratio, which are’ the important ‘factors of the U obtained in practiceiand in the operation of the a
present invention. _
present improved process, these furnaces being
In accordance with the present invention, it; those. to which reference was made previouslyw
has been determinedthat the excess blast result 75. herein.
2,404,4611
Table? I;
Furnace"
#5
“D”
Operated .by
“D”
present
Western op~
rated in ac
#5.
Western
improved
oordance
1
process
with present‘
'
HIIDI‘OVed' . ‘
7 .'
process
Volume of turnacein. cu. it __________________ .; ______ _. ______._.__ _____________ __
Hearthdiameter _________ __
_...
'
.
I
'
Area of the hearth in sq. ft. __________________________ ._
_
,
,
,‘ooo-
21’0”
21'0”
25’0”
25’0”
' 346. 4
346. 4
490.9
490. 9
Charge
1. 92
721
1,142.
1, 049
1, 440
Minutes per gross ton ..... ._- _____ ..
2. 00
1. 26’
1. 37
1.00
Total weight of charge per minute“
3, 500
6,100
4. 690
6, 375
Total per cent of iron per minute.
29. 50
32. 32
32.55
33.00
Total pounds'of iron per minute._
TotaLper centoi carbon perminu
925
24. 30
1, 670
20. 00‘
1, 580
22.38
2,100"
20. 00
l, 050
l. 275 ,
. ~. 994
1,185.. '
Gross tons pig iron per day (1440)..
_
2. 32
Total pounds of carbon per minute-
_
817
1,078
Pounds of carbon burned per ininut
_
772
1,010
Same at tuyeres burned per minute
_
600I
728.
Per cent tot carbon burned tuyeres
_
73'. 001
Pounds carbon per gr. ton pig iron.
........... __
1,634.
Blast
’
2. 50
._
2.85
730.
868 '
66. 00 '
70500-v
68.301»
1,360
1, 438
1, 275.
,
Total cu. ft. wind per minute _________ .; _____________ _.
54, 470
54, 470
65,’ 000
6‘5, 000 ‘
Total cu. ft. wind per minute required“
44, 8770
54, 470
54-, 850
65,000
Total cu. ft. wind per minute excess_-..__-__.
.9, 600
0
Total cu. ft. wind per minute excess per cent.-.
17. 50
Total cu. ft. wind per pound carbon .......... ..
Same required at tuyeres _________ ._
'
Pounds oxygen excess at tuyeres.
Total pounds oxygen/gross ton pig iron.
O
75.2
‘ 75. 2
75. 2
968
-1, 150
' 1,150‘
968
970
. 1, 150
0
0
_
1, 936
1, 320
1, 576.
_
1.11
1. 55
1. 46
38. 75
,
15. 50
. ()1
1,150.
'
1.64
.......... ._
12. 32
_
1. 72
1. 321‘
L 83'
-__._
81.05
__________ ..
38.70
0.90
23.75
1.10
__________ __
0/
Ratio O/C percentage decrease...
____.
__...
__.__
.
l
4.165
4,165
_
0
Total wgt. blast per day (1440')..
Total wgt. ohargeper day (1440’)
_
__.__
5, 999,000
,7, 630,000
Per cent ol'increase in tot. chge__
Increase of G. T. pig iron/day_
_
.
of increase . . . . _ . _ _ _ _ _ _ . . _ .
185 ____________ ._
17.50
Total pounds of-blast per minute.Total pounds of blast per minute req.
cent
75.12v
798
_
Per cent of ‘excess ________________ __
0 '
' ‘ \ 0'
, 90.0
968
170_
Per cent of excess ___________________ _.
.
15. 50"‘
75. 2
> i 75. 2
‘
Same required tuyéres per minute.
10, 150"
0 '
90. 8v
Total pounds oxygen per minute-
Per
.
.
Burdensratio--10--_-________.-___-..____.__-.____.-.
V
v
'
0. 90'
18. 20
4, 975
4,100
'
4, 975
4,975‘
18. 00'
7, 164, 000.
6, 815000" ‘
a,‘ 0
7, 164.000
911811.000’
61. 50
_ _ _ . . . _ _ _ _ ..
35, ()9v
391
.45
Fur. vol. wasted by excess bl., cu. ft.
13, 850,000
Tot. wgt. of excess blast/day, lbs...
_ 1. 050, 320
Per cent of total blast wgt ........................... ._
17-
0
0
0
The above demonstrates that the‘ Western fur
'
nace, when operated in‘ accordance with th'epres
ent improved procedure, will have a. burden. ratio
of 2.85 or greater than 2.25, the burden ratio be
ing the ratio of the total Weight of the metallic,
mix of the charge introduced into the furnace to
the total weight of coke in the charge (4133 lbs. 50
metallic mix per gross ton of iron+1450~ lbs. of‘.
coke per gross ton ofpiron=2.85). It Will also
.3735
14, 616, 000 .
1, 118, 600 .
27.50
'
.0. ,
0
.0
of ?xed-carbonin-the charge to the free oxygen.
in the blast, greaterthan 1.00, butless than 3.00,
and a ratio of total Weight of oxygen in the blast
to reducibleoxygen in the charge less than 1.75,
but not less than 0.75.
'
-
\
In taking‘over any operating ‘furnace, the ?rst .
consideration, in operating in accordance With-the
improved process, would be the ascertaining of .the
established-I production rate and the maximum‘
available ' blast, or; preferably, the established
have a ratio of total weight of charge’to total
maximum operatingv blast. Practically every
charge per gross ton+4975 lbs. blast per gross 55 charging unit has an unused charging capacity-of}
from aboutB'O per cent 130.50 per cent, sothat there
ton=l.28) ; a ratio of total weight of ?xed carbon
weight. of blast greater than 1100 (6375lbs; of
in the charge to free oxygen in the blast greater ' \
is su?icientcapacity available to meet the require;v .
men-ts for charging according to the improved
than 1.00 (1275 lbs. of carbon in» charge per gross
process. After these determinations are made
ton of pig iron+ll50 lbs. of oxygen in the blast.
per gross ton of pig iron=1.1l); and a ratio of 60 then Table'II'would‘ be consulted for ascertaining
thecorrect-lweights of carbon. and of'metalliciron m ;
total Weight of oxygen in the blast to the total
for makingvv up the-indicated burden. The analy;
weight of the reducible oxygen in the charge lessv
sis of the regular operating burden would be de
than 1175 (1150 lbs. of oxygen in the blast per
termined; and from such analysis, and upon the
gross ton of pig iron->900 lbs. of reducible oxygen
in the charge=1.28).
v
'
.
Generally speakingthe methodiof the present
invention comprises preparing a‘ charge of hema»
tite ore in natural hydrated condition and con
taining not less than 4.0 per cent iron, coke, and
65 basis of the established maximum operating blast,
there wouldlbe determined a burden in conform
ity with the chemically balanced requirements
outlined: in Table II, that is, by dividing the cubic
feet of blast per minute by the factor ‘31.00, and
limestone, introducing the resulting mixture into 70 also by the factor 51.00,‘ for the purpose of ascer-w '
taining; first; the total Weight of the iron in the
a blast furnace and blasting the said: mixture‘
burden, and,.second, the total weight of carbon
with super-heated air, While maintaining a-bur
in the burden. Then there would be determined
den ratio greater than 2.25 but less than ‘3.25,, a‘
the respective. requirements 'of the number of
ratio of total Weight of ' charge‘ toblast' greater"
thanzLOObut less than 3.00, a ratio oitotal weight.’ 15 charging rounds and the total weight‘ of each‘ ,
2,404,461‘.
7',
8
round required for the operation in accordance
Round'2, which is composed as follows:
with the improved procedure. vThe procedure, then, in taking over a given furnace, is as follows:
.
Pounds
Coke: 100% of that charged into the fur
First, maintain the blast at the established
maximum operating blast rate, at not less than 5
nace in regular rounds'for normal fur-'
1200°
F.;
_
'
.
.
nace operation _______ -l ____________ __ 13,000
Second,’charge one cokeablank', the'total weight’ -
Stone: 60% of that charged into the fur-
of which is equivalent to the total weight of the ‘
nace in regular rounds for normal fur-~
coke in two regular operating rounds plus a total‘ ’
nacev operation ___'_ _________________ __
‘
‘ 4,200
weight of stone which is'equivalent to the total 10 Ore: 40% of that charged into the fur- ‘
weight of stone that is'charged in one'regular op.
erating round;
.
I
'
‘
vnace in regular rounds 'for normal fura »
a.
- nace operation ________ _'____'_________'_~.: 16,000
1
In normal furnace operation the furnace is
charged in “rounds” each "round”. being com
posed as follows:
Coke __
.
____
‘
‘
_
__;_
Stone
15 ~
Pounds
Total ____ __V__l_*_ ___________ __‘__r__ 133,200
13,000
__
,
,
r
--
7,000
__
40,000
Coke
, Stone
Ore
Total
____ _'____Y____ 60,000
Now, in accordance with: the second-step of chang- '
ing a ‘conventionally‘operating furnace tofthe
‘present improved process as described above,
wherein there have been charged intothe <fur
nace 26,000 lbs. of coke _(one coke blank, 111300031
weight of whichis equivalent to the total weight
of the coke in two ‘regular. operating rounds) plus
operation, andis reachedgradually, as indicated
7,000 lbs. of stone (total-weight of stone that is
charged in one regular operating round). This
nace is based. upon a constant weight of coke,
gives the very large “back-log” of‘heat required
This last-is a regular round for normal furnace
above. The increased burdening of the blast fur-v
30
'for operation of the furnace. No additional coke
blanks are necessary.
_
.
thence increasing‘ the weight of ore and stone in
successive “rounds.” Decreased burdening is ac,
complished by maintaining a constant weight of
-
coke and decreasing the weight of stone and ore.
Third, begin charging‘in rounds as follows:
Round 1, which is composed as follows:
_
Stated in another way, the percentages referred
35 to in the above tables are percentages of the var
'
'
Pounds
ious quantities of the materials, coke, stone and
Coke: 100% 01015301153433 into thefur- ~
nace in regular rounds for normal fur
ore, that are charged into the furnace in regular
nace operation_____ __~_ _____________ __ 13,000
rounds for normal furnace operat1on.
Stone: 50% of that chargedinto the fur-
-'
The charg11’1g,bl0W111g.'aIld Operatlng Ofa blas
'nace 1n regular rounds for normal fur-
_
nace operat1on ____ ____ -1.- __________ __
40 In accordance wlth the chemically balanced pres
3,500
ent process 1s illustrated in the following table
Ore: 25% of that charged 1nto the furnace
(Table II), the values 1n the said table being
In regular rounds for normal’ furnace
predicated on the use of hematite ore in natural
operatlon-e -------- --'~' ------------- -- 10,090
.
~
————
Total“, ____________ -3 __________ __ 26,500
hydrated cond1t1on and‘contammg not less than
4
.
V
40 per cent won:
Table II
1
.1 Blowper min.
"
Charge per min.
cu ft _
m'in_'
~
3
Pounds
Pounds
oxygen _
carbon
_
per
gr. ton
Pounds
, iron
P
Ggggns
per day
d
01.111
S
carbon
burned
lagggeilt
5'
by blast
carbon
iron
'
1,774
1,900
0.050
2,215
95,000
1, 030
(1, 333
3,000
0. 035
2, 100
1, 207
Gr. '1‘
90,000
35, 000
, 000
75,000
72, 500
70,000
07,500
05,000
1,593
1, 505
_ 1, 420
1,330 '
1, 235
1, 240
1, 195
1, 150
1,705
1, 003
1, 570
1,472
1, 421
1, 375
. 1, 325
1, 275
2, 900
2, 750
2, 530
2,420
2, 335
2, 200
2, 130
2, 097
0.725
0. 705
0. 303
0,900
0. 912
0. 944
0. 932
1.000
1, 030
1, 332
1, 730
1,033
1, 592
1, 525
1, 433
1,440
1, 200'
1, 133
1, 003
1,000
900
932
900
305
02,500
1,105 7
1,225
2,015
1.042
1,335
330
70.0
.
N. T
00,000
57, 350 '
1, 002
1, 024
1, 013
1, 175
1, 135
1,932
1, 300
1, 355
1. 033
1.103
1. 132
1, 330
1, 231
1, 275
300
700
700
70. 0
70. 0
70. 0
I
52,500
50,000
47, 500
45, 000
r
974
1, 125
1, 075
923
335
. 340
1,025
_ 930
930
3,235
1,333
.
100,000 _
57, 500
55, 000
7
t
Hill 68
vBlast
5
3
M_
‘
5
- 70.0
4
70. 0
70.0
70. 0
70. 0
70.0
70. 0
70. 0
70. 0
70. 0
1,772
1. 131
1,200
732
70. 0
1, 000
1,015
1,532
1.240
1.300
1. 372
1,105
1,107
1, 054
700
004
031
70.0
70.0
70. 0
1, 000
790
332
1, 450
1. 444
42,500
752
333
1,371
1.535 '
950 '
500
70.0
40, 000
r 703
734
1, 291
1. 025
900
532
000
70. 0
70. 0
37, 500
004
732
1, 210
1. 750
343
493
70. 0
35,000
020
033
1,129
1.375
775
404 v
70.0
32, 500
30,000
570
539
033
533
1, 050
974
1. 921
2.107
720
005
432
400
70. 0
1 70.0
27.500 '
25,000
435
442
541
490
333
307
2.334
2.000
v 010
555
303
330
V
22, 500
393 .
440
720
2. 930
500
300
70. 0
20,000
.354 ‘
392
045
3.250
445
205
70.0
51. 0
31.0
Empirical
53. 5
'
______________________ __
dlVlSOl'S
Norm-Divide O. F. M; blast by empirical divisors for desired duotients.
70.0
70.0
.75. 0
70. 0
~
'
"
1
2,404,451
9
.
intermediateblowingcapacitiesrequire the
10
'
portantly, the operation of a blast, ,furnaceby ‘
respective, proportionate, intermediate weights of
“metallic iron and carbon, as indicated herein;
blowing itv with lawless, total weight or blast '
(pounds of wind perv .net ton of iron) ‘than its
Additionally, the following table (TableIII)
total‘ weightvof, the solid charge gpounds‘of wind I
‘shows the complete chemical balance Of the vital :15 per net- ton “of. all solids, ore, coke, 1' nd lime
‘faetors concerned in the operation of the blast
stone). per net ton of'iron, and that in'thesolid
.iurnaces shown in Table I, showing, a comparison
charge thetotai weigh-t of, gamma ,iemam
between the conditions as they were in standard
.tained greater than
total-weightof oxygen
,operationandas they areoperatins thetlletnical(that is, the pounds of oxygen in the wvind) in
it? balanced present unmoved process for .msllr- 11“ the blast
"“m
111g
maxlmu
the riruic;
ma e ‘5 en .3’ ,
i _
Table III
c
‘
e
- presented
'
"‘
V The following additional data, is
as
» i_
7'
.r
‘showing furtherthe advantages arising ‘from the
,
vioperation of blast jiurnaces in accordancewith ,
‘Epic, reggae x15 vvthe present invention. ‘J'I‘his operating data was
D
gm 1% wind per minutgié__________________ __
Pounds Garbo“ permlznum _________ H
5
con
soxygen per-mind
£01m? carbon perigmtmte should bc_
°“§1)0S_f{"_’?_1_’_°f_‘_‘f_ffj"""M"
817
1,768
1 1i},
Minutes-075a?15511::
,
cg
Cu. it. wind per gr. ton.
_
108,940
0___; _______________ __
P l); ......... "9.16.065"
xv'en
...... ..
.
1,050
same raw materlals were used, the same blowmg
.
___
H,
d
-
7 21100
ounsoxygcn per. gr.
onsaving
.
of iron under identical conditions,'inso-far as was
89,050
.2
mss-lble-
1.
The method of the -pres-e~nt*mventl9p or
-
'
>
it
~
g
_.
V
.
25 was used on furnace No. '1, but‘furnace No. 2
1,130
1,150
,
Was operated according. to the
,
4
_
»
conventional
g
>
I
method characterized by many blast ‘ volume
gums;‘égggggégg‘éfign'ga
_
c
the same technique and producing the same kind
1,01%? carbon per gr. to
‘On. it.wind per gr. ton saving.
_
personnel was'used 0,11 both furnaces, utilizing
caggg
_
1,
1, g 20 inventions were employed and the same operating
- w
01m
6?, (1)98
>
1,
jjjjj
Grossgons iron per (my.
‘obtained on two blast {furnaces 'operatinghat
Donora, Pennsylvania. Blast furnacesNo. '1 .and'
‘No. Z’Were identical in all measurements. ‘The
5'4,
___.___.,
.,
Western ‘
>
43,940
On. it. wind per gr. ton savmg p. _,
'23
changes, extra coke charged every fourth charge
24,050 30
,
_,
0
.27
,
freqlilent burden 'Fha’nges' sch-e
.
'dlf' '
V
l
'
ferencesm the‘ operation Qf;the»;two furnaces are
7 shown cl??l‘ly-byjlihg following on rating data.
Iiable IV
No.1
Period covered by the test_____
July, 1942, 31 days__ July, 1942, 31 days.
Total net tons pig iron (basic)-
24,552 _________ __'_,__. 19,778; ‘
Total net tons pig iron per day
Total net tons pig iron increase/day
___‘_ 792
‘
Total net tons pig iron percent/day“
Cu. ft. blast per min__
.> ‘ “No.2;
,
____ __
Weight of blast per mi
1
038.
0.
24.10% ____________ __
0.
43,200»(c0nstant) _ __-
40,500 to 46,500.
-
'
i ;
_ 3,305# (constant). ___ 3098# to 3590#.
Minutes per net ton pig iron.-.
1.83. r _'___.'; _______ __
Cu. ft. blast per net ton pig iron_ _.
Weight blast per net ton pig iron- _
Weight of blast oxygen per net ton
Weight of solid carbon per net ton _____________ ._
Aver. 1,56
Weight of solid carbon per net ton percent increase.
9.50 .
Weight of solid carbon ton pig iron burned at tuyéres
1,l67#=74%.
Wgt. oxygen req. for comp. combustion __________ __
_.__
Over-blast equal to __________ ._
__._
-
1,550#.
'
269#.
15,000 cu. ft,
Wgt of solid chge. per net ton pig ll'Oll.
____
Wgt of blast chge. per net ton pig ll'Oll
____
Cu. ft. of blast per net ton pig iron____T ___________________________ _- ’
.
Ram
6, 0#; v
'7,996#. ’
104,500.v
'
~
1
'
‘ ‘
_
Present improved
I
Ratio burden wgt. of metallic mix to coke __________ __
-
ra'ios
1.91 2.25 to 3. 25‘
Ratio Wgt. of solid chge. to wgt. of blast
0.80 1.00 to 3.00
Ratio wgt. of solid carbon to blast oxygen ______ __
0.86 1.00 to 3. 00
Ratio wgt. of blast oxygen to reducible oxygen.
2.28
Ratio pounds of Fe per 1# C_ r____=_________ __
_
Ratio pounds of Fe per 1# G percent increase
_._
Ratio 00 to CO2 in top gases ______________ __
Ratio reduction e?iciency shown by top gase _
Ratio overall thermal e?icieucy as shown by th
oxygen at the tuyéres.
'
2.28.
92,380 to 106,700.
7,067# to 8,163#= 7,9961%.
1,640# to 1,894#=1,820#,
____
Excess blast oxygen ____________ __‘
I ' ‘
,
'
.75 to 1. 75
1.17,
0.
___
_________ __
2.26.
1.00.
tio of C to blast
0.62.
In accordance with the present invention,
there is provided a, stabilized operation wherein
Summary of operations on No. 1 and No. 2
blast ' furnaces at Donora, Pennsylvania, Jmg,
the reactive elements are all maintained in chem-
1942.
ical equivalency throughout the operation, pro- ‘ 70- '
I
I
> ‘i
‘_
,
r
Both blast furnaces producing basic, iron.
,
1 v
V,
ducing substantially greater yields ofymetal with
substantially higher efficiencies of operation and,
No. 1 blast furnace operated on present improved method characterized by constancy.
'
consequently, reduction in quantities of the re-
No. 2 blast furnace operated on’ conventional
actants, with attendant lowered costs.
It will be seen from the foregoing that the im- 7'5,
proved process .of this invention comprises, im-
method characterized by frequent changes in
blast volume and also in burden ratio- due to
the charging of extra coke every fourth charge.
magic
011-,
5 “No.1 produced;
1.2
_
1 v 24.10% more pig iron product, using
, ' 9.50% less solid carbon
.
V
féi‘jatorsrbeliéve ‘are uncontrollable in blast, furnace
~
‘Operations.
_' >
' ' 25,450 cu. ft. less blast and eliminated
15,000 cu. ft. of overblast thus demonstrating
' r - 38.00% more overall thermal efficiency and
60.00% more‘ reduction e?iciency as shown by ‘I
the ratio of CO to CO2 in the top gases and
.- falsoin
'_
.
.,
,
.
.
4
, It maybe pointediout’ inthisconnection' that
in customary operations blast furnaceef?ciencyis
;
based upon the ratio of net tons of pig iron
per square foot'of hearth area, and the ratio of
2.65 is: considered to be representative of-good
practice.
~’
'
'
»
'
-Inaccordance with the present invention, reg-_
ular attainment of ‘ratios of from ‘between 2.90
11.10% more metallic iron per. pound of solid
and 4.90 is experienced by the use of the operating
, *?ln'the present improved method, all the burden 1 I ratios'set forth above herein.
1 ingredients are, weighed in chemical equivalency
This application is a continuation-in-part of
‘
Carbon
‘
>
‘ against the ?xedweight of oxygen that is con
co-pending application No. 391,211, ?led April 30,
tained in the chosen blast volume inithe ratio of 15 1941.
i.1.33#.of'oxygen for each 1# of carbon that ar- ,
I rives at the :tuyéres. .Only seventy-?ve per cent
I claim:
The method of operating a blast’ furnace for ‘
producing pig iron, which comprises preparing a
charge including iron ore, coke and limestone, in
j ._of the total'carbon arrives at the tuyéres for corn
:bustion by the blast oxygen. The remainder'of
‘ the total carbon charged in the furnace undergoes 2.0 troducing the resulting mixture into a, blast fur- >
‘ combustion above'gthe tuyéres in the various car
nace, blasting the said mixture to metallic iron
Ibonlcons'urning,‘direct reactionsf
'
'
Likewise, 1.25'# to 1.81# of metallic iron per
i'ea'ch'vlit‘o‘f blast oxygen are charged in the blast
[furnace burden. ' These computations are readily
{made by the usejof the factors 31.00 and 51.00 as
.‘explained above herein.
'
~ ‘*1 Obviously, ‘these ratios are effective only on the
fbasisjof constant maintenance of theychosen blast
jivolume ancl'upon a--' constant burden ratio.
" , Iii-the -~-conventional'imethod, no‘ similar. or
‘equivalent computations are provided, nor in
;deed can they be because of inconstant blast vol-.
Iume and burden ratio, consequently,_ chemical‘
~ flequivalency control is never attempted because
with a constant blast of superheated air, while
maintaining a burden ratio greater than 2.25, but
than 3.25, a ratio of total Weight of charge to
25 less
blast greater than 1.00, but less than 3.0, a ratio
of total weight of ?xed carbon in the charge to
the free oxygen in the blast greater than 1.00, but
less than 3.00, and a ratio of ,total weight of
'
oxygen in the blast to reducible oxygen in the
charge less than 1.75, but not less than 0.75,,the
. , said ore-‘being hematite me ‘in natural hydrated
condition and containing not less than 40 per cent
iron, and maintaining a constant volume of blast
_ through the’ tuyeres during the entire operation.
{"of the “many variables”'that all conventional op- '
' STANLEY A. SANFORD.
Документ
Категория
Без категории
Просмотров
0
Размер файла
1 050 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа