Mill Material Balance
12.1.2
The Evaluation
The result of computer calculation with the use of the same input as for the example in Chapter IX is shown on Sheet-II (Evaluation) that is for the overall and individual performance of each mill, such as: §
The Material Balance, overall and individually (page 1).
§
The overall performance of the tandem (page 2).
§
The individual performance of each mill (page 2).
§
The actual versus the projection of Brix Curves (page 3).
§
The approximate mill power (HP) required (page 4).
XII-3
Mill Material Balance
M I LL M A T E R I A L B A L A N C E
E V A L U A TI O N O F P E R F O R M A N C E
SUGA R F A C TORY E X A M P LE M I LL TRA I N : 2 CC + 5 MILLS CA N E Q U A LI TY Ma Ma s s kg k g / h r .
C A P A CI TY : M I LLI N G S E A SON
4 , 3 5 1 . 0 TC TCD 19 77
% pol =
1 0. 3 2
% brix =
1 3. 4 1
% fibe r =
1 6. 0 7
% br ix
Br i x kg/hr.
% pol
Pol kg/hr.
Density kg/dm3
V ol ume d m 3/ h r .
P a g e : 1
PERIOD : X Date : La s t d a t e
E v a l u a t i o n:
M I LL I - Ju J u ic e in - Fiber
1 52 , 15 8 2 9, 13 3
1 5 . 98
2 4, 31 1
12 . 30
1 8, 70 9
1. 07 1 38 1. 60 0 00
1 42 , 02 0 1 8, 20 8
M I LL I Dk = L=
1 0. 0 2 2 1. 3 3
r= r' =
1 . 3 71 2 1 . 3 59 0
Tota l i n Ex E x t r a c t e d j u i c e
1 81 , 29 1 6 8, 76 1
1 3 . 41 1 7 . 46
2 4, 31 1 1 1, 96 9
10 . 32 14 . 05
1 8, 70 9 9 , 63 1
1. 13 1 46 1. 07 7 88
1 60 , 22 8 6 3, 79 2
n= h=
268 0 . 4 12 3
m= h' =
0 . 3 37 8 0 . 3 91 0
8 3, 39 7 2 9, 13 3
1 4 . 80
1 2, 34 2
10 . 89
9 , 07 8
1. 06 6 08 1. 60 0 00
7 8, 22 8 1 8, 20 8
i= Ved o =
2 . 20 7 4, 15 4
K= HKej =
2. 28 8 0. 47
1 12 , 53 0
1 0 . 97
1 2, 34 2
8. 0 7
9 , 07 8
1. 16 6 89
9 6, 43 6
Ve d =
7 0, 33 1
kB =
1 . 0 89
- J u ic e in
1 46 , 89 8
1 2 . 25
1 7, 99 4
8. 9 7
1 3, 17 4
1. 05 5 50
1 39 , 17 4
Dk =
1 0. 2 3
r=
1 . 3 49 9
- Fiber Tota l i n
2 9, 13 3 1 76 , 03 1
1 0 . 22
1 7, 99 4
7. 4 8
1 3, 17 4
1. 60 0 00 1. 11 8 50
1 8, 20 8 1 57 , 38 2
L= n=
2 1. 3 3 244
r' = m=
1 . 3 47 7 0 . 3 44 3
E x t r a c t e d j u i c e - Ba B a g a s s e juic e
8 6, 18 5 6 0, 71 3
1 2 . 48 1 1 . 98
1 0, 72 3 7 , 27 1
9. 2 9 8. 5 5
7 , 98 2 5 , 19 2
1. 05 6 46 1. 05 4 14
8 1, 57 9 5 7, 59 5
h= i=
0 . 3 63 3 2 . 00
h' = K=
0 . 3 35 9 2. 80
- Fiber To T o t a l b a g a s s e
2 9, 13 3 8 9, 84 6
8 . 09
7 , 27 1
5. 7 8
5 , 19 2
1. 60 0 00 1. 18 5 26
1 8, 20 8 7 5, 80 3
Ved o = Ve d =
6 0, 73 7 5 6, 15 4
HKej = kB =
7 4. 44 1 . 0 16
- B a g a s s e juic e - Fiber T o t a l b a g a s s e
M I LL I I
M I LL I I
MI M I LL I I I
M I LL I I I
- Ju J u ic e in - Fiber
1 12 , 70 3 2 9, 13 3
9 . 10
1 0, 26 0
6. 4 8
7 , 30 3
1. 04 2 34 1. 60 0 00
1 08 , 12 5 1 8, 20 8
Dk = L=
1 0. 2 1 2 1. 3 3
r= r' =
1 . 3 35 5 1 . 3 36 4
Tota l i n Ex Ex t r a c t e d j u i c e
1 41 , 83 6 6 3, 50 1
7 . 23 8 . 90
1 0, 26 0 5 , 65 2
5. 1 5 6. 4 5
7 , 30 3 4 , 09 6
1. 12 2 72 1. 04 1 91
1 26 , 33 3 6 0, 94 6
n= h=
216 0 . 2 77 9
m= h' =
0 . 3 54 3 0 . 3 31 5
4 9, 20 2 2 9, 13 3
9 . 37
4 , 60 9
6. 5 2
3 , 20 7
1. 04 2 88 1. 60 0 00
4 7, 17 9 1 8, 20 8
i= Ved o =
2 . 00 4 1, 04 8
K= HKej =
2. 58 7 2. 47
To T o t a l b a g a s s e
7 8, 33 5
5 . 88
4 , 60 9
4. 0 9
3 , 20 7
1. 19 8 02
6 5, 38 7
Ve d =
4 8, 95 9
kB =
0 . 9 78
M I LL I V - J u ic e in
9 3, 23 5
6 . 33
5 , 90 3
4. 3 8
4 , 08 7
1. 03 0 85
9 0, 44 5
M I LL I V Dk =
1 0. 2 0
r=
1 . 3 21 4
2 9, 13 3 1 22 , 36 8
4 . 82
5 , 90 3
3. 3 4
4 , 08 7
1. 60 0 00 1. 12 6 23
1 8, 20 8 1 08 , 65 3
L= n=
2 1. 3 3 191
r' = m=
1 . 3 25 3 0 . 3 63 1
5 1, 99 0
5 . 75
2 , 98 9
4. 0 6
2 , 11 1
1. 02 8 89
5 0, 53 0
h=
0 . 2 61 4
h' =
0 . 3 37 1
4 1, 24 5
7 . 07
2 , 91 4
4. 7 9
1 , 97 7
1. 03 3 32
3 9, 91 5
i=
2 . 00
K=
2. 47
1 8, 20 8 5 8, 12 3
Ved o = Ve d =
3 4, 10 8 4 3, 98 6
HKej = kB =
7 0. 61 0 . 9 08
- Ba Ba g a s s e juic e - Fiber
- Fiber Tota l i n Ex Ex t r a c t e d j u i c e - Ba Ba g a s s e juic e - Fiber To T o t a l b a g a s s e
2 9, 13 3 7 0, 37 8
4 . 14
2 , 91 4
2. 8 1
1 , 97 7
1. 60 0 00 1. 21 0 85
- J u ic e in
7 6, 37 3
3 . 82
2 , 91 4
2. 5 9
1 , 97 7
1. 01 7 72
7 5, 04 3
Dk =
1 0. 3 4
r=
1 . 3 01 0
- Fiber
2 9, 13 3
1. 60 0 00
1 8, 20 8
L=
2 1. 3 3
r' =
1 . 3 01 0
M I LL V
Tota l i n Ext ra cte d j ui ce - Ba Ba g a s s e juic e - Fiber To T o t a l b a g a s s e
M I LL V
1 05 , 50 6 4 4, 03 3
2 . 76 2 . 94
2 , 91 4 1 , 29 5
1. 8 7 2. 0 0
1 , 97 7 881
1. 13 1 42 1. 01 7 72
9 3, 25 1 4 3, 26 6
n= h=
193 0 . 2 46 2
m= h' =
0 . 3 61 5 0 . 2 87 5
3 2, 34 0 2 9, 13 3 6 1, 47 3
5 . 01
1 , 61 9
3. 3 9
1 , 09 6
2 . 63
1 , 61 9
1. 7 8
1 , 09 6
1. 01 7 72 1. 60 0 00 1. 22 9 83
3 1, 77 7 1 8, 20 8 4 9, 98 5
i= Ved o = Ve d =
2 . 00 3 2, 90 7 3 8, 42 1
K= HKej = kB =
2. 43 6 8. 03 0 . 7 71
The Computer Program Program
XII-4
Mill Material Balance
M I LL M A T E R I A L B A LA N C E S U G A R F A C TO R Y E X A M P L E M I LL TRA I N
:
CA P A CITY
2 C C + 5 M I L LS
C A N E Q U A LI TY
:
M I LLI N G S E A S O N
% pol =
10.32
% b r ix =
13 .41
A C T TU UA L P E R FO R M A N C E D e s c r i p t i o n C a n e :
I m b ib it i o n w a t e r :
M ix e d ju ic e :
L a s t m ill b a g a s s e :
Sym b o l
V a lu e
- c r u s h in g d u r a t io n
jg
- c r u s h e d p e r h o u r
Qj
U ni t
4,351.0 TCD
La s t d a t e
Ta r g e t 4,800.0
2 4 . 0 0 ho ho u r s 1 81 ,291 KC H
2 4.0 0 2 00 ,0 00
gnt
83 .93 % c a n e
- weighed, total
Gi
84 3.1 T ons
1,581.3
8 3.9 3
- w e i g h e d p e r h o u r
G ij
3 5,12 8 kg/hr.
65,887
- % f i b e r
g is
1 2 0 . 5 8 % fib e r
205.00
19 .38 % c a n e 0 % G ij
3 2.9 4 0
- % c a n e - o n b a g a s s e 1
g it g ia 1
- o n b a g a s s e 2
g ia 2
0 % G ij
0
- o n b a g a s s e 3
g ia 3
0 % G ij
30
- o n b a g a s s e 4
g ia 4
- weighed, total
Gnm
3 , 7 1 8 . 7 To To n s
4,800.0
- w e i g h e d p e r h o u r
Gnmj
1 54 ,946 k g/hr.
2 00 ,0 00
- % c a n e
gnmt
85 .47 % c a n e
- p o l
pnm
11 .40 %
1 0.0 4
- b r i x
bnm
14 .69 %
1 2.6 0
HKnm
77 .62 %
1 0 0 % G ij
70
100.00
7 9.6 8
- total per hour
Gal
- % c a n e
g a lt
- p o l
pal
1.78 %
- b r i x
bal
2.63 %
2.58
47 .39 %
4 8.7 8
kf
6 1,47 3 k g/hr. 33 .91 % c a n e
65,887 3 2.9 4 0.94
- d r y m a t t e r
zk
50 .03 %
5 1.3 6
- j u i c e t o f ib e r
nss
111.01 %
105.00
3 1 . 8 4 % fib e r
3 2.9 7
- B rix m ill # 1
H P B -I
gnhs
49 .23 %
5 3.4 0
- B rix t o t a l
H P B -t
93 .34 %
9 3.6 7
HPG
94 .14 %
9 6.9 9
H P G 1 2 ,5
95 .44 %
9 7.6 6
PSHK
94 .51 %
9 7.4 4
- s u g a r - s u g a r o n 1 2 ,5 % f i b e r R a t io o f ju ic e p u r i t y - can be expected
kt
9.08 % c a n e
9.08
- i n m ix e d ju ic e
knm
8.59 % c a n e
8.99
- l o s s i n b a g a s s e ( r e l a t iv e )
khar
5.38 %
1.05
I N D I V I D U A L P E R F O R M A N C E M I L L N O : --- ------- ----->
I
II
E x t r a c t io n :
4 5.1 9
58.67
- J u ic e
En
=
N o r m a l v a lu e =
> 60
> 60
III 56 .34 > 60
IV 55.76 > 60
V 5 7.6 6
% %
> 60
- Pol
Ep
=
5 1.4 8
60.59
56 .09
51.64
4 4.5 5
%
- B rix
Eb
=
4 9.2 3
59.59
55 .08
50.64
4 4.4 3
%
K
=
2.28
2.80
2.58
2.47
2.43
C o m p r e s s io n r a t i o :
N o r m a l v a lu e = J u ic e e x t r a c t e d b y f e e d o p e n in g
y
=
m e a n in in g = l =
R o lle r s h e l l d e f l e c t i o n
m e a n in in g = B a g a s s e : - no-void density
da
=
2 ,4 , 4 - 3 , 3 2 ,6 , 6 - 3 , 5 2 ,6 , 6 - 3 , 3 2 ,5 , 5 - 3 , 2 2 ,4 ,4 - 3 , 0 -0 .14 0.71 0.44 0.31 0.25 n o e x ' t i oe oe x t r a c t e e x t r a c t e e x t r a c t e e x t r a c t e d -0 .10 -0.13 0.25 0.35 0.19 safe 1 .1 669
safe danger danger 1.1853 1.1980 1.2108
%
safe 1 .2 298 k g / d m 3
- a b s o r p t io n a b i l i t y f a c t o r
r
=
1 .3 712
1.3499
1.3355
1.3214
1 .3 010
- ditto, norm a l
r'
=
1 .3 590
1.3477
1.3364
1.3253
1 .3 010
gat =
- % cane
F ib e r :
:
- j u i c e c o n t e n t
- j u i c e lo s s in b a g a s s e
Cr C r y s t a l :
Date 1 6.0 7
Q
- f ib e r c o n t e n t
E x t r a c t io n ' s :
1977 % fib e r =
- crushed, tota l
- p u r i t y
P a g e : 2
E V A L U A TI O N O F P E R F O R M A N C E 4 , 3 5 1 . 0 TC TC D PERIOD : X
6 2.0 7
49.56
43 .21
38.82
3 3.9 1
%
- pol
pa
=
8.07
5.78
4.09
2.81
1.78
% %
- brix
ba
=
1 0.9 7
8.09
5.88
4.14
2.63
- dry matte r
zk =
3 6.8 6
40.52
43 .07
45.54
5 0.0 3
- inde x
c
=
0.41
0.52
0.60
0.66
0.76
kg / d m 3
- loading
q
=
161.98
174.26
197.24
223.27
217.97
gr/dm 2
- r e d u c e d lo a d in g
q' =
123.18
129.80
147.20
166.80
160.63
gr/dm 2
N o r m a l v a lu e = - % bagasse
kf = N o r m a l v a lu e =
The Computer Program Program
%
1 2 0 - 1 3 0 g r / d m 2 e s c r i b e d ro r o l l e r s u rf rf a c e 2 5.8 9 25-35
32.43 28-38
37 .19 32-42
41.40 37-47
4 7.3 9 45-50
% %
XII-5
Mill Material Balance
M I LL M A T E R I A L B A LA N C E S U G A R F A C TO R Y E X A M P L E
M I LL TRA I N : 2 C C + 5 M I L LS C A N E Q U A LI TY % po l =
CA P A CITY
:
THE B RIX CURVES 4 , 3 5 1 . 0 TC TC D PERIOD NO.
M I LLI N G S E A S O N 1977 % b ri x = 13.41 % f ib e r =
10.32
Date
:
P a g e : 3 :
X
La s t d a t e
16.07
Va V a l u e f o r --- - - - - - - - - - - - - > % b r i x , e x p e c t e d - - - - - - - - - - - >
M il ill I 16.02
M ilill I I 9.82
M ilill I I I 5.60
M il ill I V 3.10
M ilill V 1.90
% b r i x , a c t u a l - - - - - - - - - - - - - - - - >
17.46
12.48
8.90
5.75
2.94
20 19 18 17 16 15 14 13 > - 12 - 11
x i r b 10 % 9 8 <
7 6 5 4 3 2 1 0 Mil l I
M il l I I
Mill I I I
E xp xp ec ec te te d C ur ur ve ve
The Computer Program Program
Mi ll I V
Mi l l V
A ct ct ua ua l C ur ur ve ve
XII-6
Mill Material Balance
M I LL M A T E R I A L B A L A N C E
M I LL TRA I N : 2 CC + 5 MILLS CA N E Q U A LI TY % pol =
P a g e : 4
P O WE R C A L C U L A T I O N
SUGA R F A C TORY E X A M P LE
C A P A CI TY 1 0. 3 2
:
4 , 3 5 1 . 0 TC T CD
P E RI O D NO .
M I LLI N G S E A SON 19 77 % brix = 1 3. 4 1 % fibe r =
1 6. 0 7
Un i t
M ill I I
:
Date :
La s t d a t e
M ill I I I
M ill I V
X
P OWER OWER CA LCUL LCULA A TION De D e s c r ip t i o n M ill h y d r a u l i c p r e s s u r e Di D i a m e t e r o f h y d r a u l ic p i s t o n
kg/cm2 mm
M ill I
M ill V
1 80 3 30
18 2 33 0
1 82 3 30
206 330
2 10 3 30
M e c h a n ic a l e f f i c i e n c y , t o t a l Ro Ro l l e r s h a f t d i a m e t e r , a v e r a g e Ro Ro l l e r s h a f t l e n g t h
% mm mm
86 4 20 4 , 2 20
86 42 0 4 , 22 0
86 4 20 4, 2 20
86 420 4 , 22 0
86 4 20 4, 2 20
To To p r o l l e r m e a n d i a m e t e r Ro l l e r l e n gt h
mm mm
1, 002. 0 2 , 1 33
1, 023. 0 2 , 13 3
1, 021. 0 2, 1 33
1,0 20.0 2 , 13 3
1, 034. 0 2, 1 33
Ro l l e r r o t a t i on Re Re d u c e d f i b e r l o a d i n g
r ph g r/ d m2
2 68
24 4
123.18
129.80
cm2 kg
85 4 . 87 30 7 , 7 51
8 54 . 8 7 3 11 , 17 1
85 4. 87 3 1 1 , 1 71
8 54 . 8 7 3 5 2, 20 4
85 4 . 8 7 35 9 , 0 43
T op r ol le r we i ght To T o t a l p r e s s i n g l o a d B a g a s s e c o e f f ic ie n t o f f r ic t ion
kg kg m
16 , 9 43 32 4 , 6 94 0. 33 78
1 7, 55 5 3 28 , 72 6 0 . 3 44 3
17 , 4 96 3 2 8 , 6 67 0. 35 43
1 7, 46 7 3 6 9, 67 1 0 . 3 63 1
17 , 8 8 1 37 6 , 9 24 0. 36 1 5
C i r c u m f e r e n t ia l forc e P o we r re q u ire d f o r m i l l i n g , a v e r a g e
kg PK
10 9 , 6 77
1 13 , 17 5
1 1 6 , 4 37
1 3 4, 22 8
13 6 , 2 47
398
382
347
354
368
1 3 . 67
1 3. 1 1
11 . 92
1 2. 1 4
12 . 62
Cr Cr o s s s e c t i o n a r e a o f h y d r a u l i c p i s t o n Hy d r a ul i c f o r c e
S p e c ific p o we r r e q u i r e m e n t
12.1.3
HP / t o n f i b e r
2 16 147.20
191 166.80
1 93 160.63
Notes for Evaluation
After a material balance for a mill tandem made completely as shown above, the next step is to define the performance evaluation together with the comments and recommendations. The evaluation for the performance of a mill tandem can be made in 4 (four) main items: §
Overall for the whole tandem.
§
Individually for each unit of mill.
§
Comparing the Brix Curves.
§
Power required for the milling.
The criterions used for the evaluation, both the overall and individuals of a mill tandem is shown above (see the sheet on page-2). The main points essentially evaluated for overall performance of a mill tandem are comparing the actual figures achieved during operation with the planned figures made by the projection, such as: §
The crushing capacity.
§
The imbibition water % fiber as well as % cane.
§
The mixed juice % cane and its purity (HK).
The Computer Program Program
XII-7
Mill Material Balance
§
The last mill bagasse for its quantity (in %cane), %pol, %Brix and the dry matter. Also the juice in bagasse %fiber (nss) and the loss of juice juice %fiber (gnhs).
§
#
The results of extraction for Brix in mill 1 (HPB-I), the total Brix by the tandem (HPB-t) and the sugar extraction (HPG).
§
The ratio of juice purity (PSHK).
§
The expected crystal obtained (kt) by and contained in mixed juice (knm) and the relative crystal loss in the last mill bagasse (khar).
While the main and essential items, which should be evaluated individually for each mill, among other things are the followings: a. Extractions There are 3 (three) extractions in milling: §
Juice extraction,
§
Pol extraction, and
§
Brix extraction.
The juice extraction is good when the value is more than 60% for each mill, and gradually decreasing for the ensuing mills. The same criterion applies for the value of Pol and Brix extractions. b. Compression Ratio The compression ratio (K) is a ratio between the no-void volume of the incoming material and the escribed volume of the delivery opening, and is a barometer for the pressing work of the milling in a unit of mill. The value of the compression ratio depends on the ability of the respective mill rollers in use. A good roller material enables maintaining a good compression ratio wills also obtaining optimal fiber index (c). c. Is juice extracted by the feed opening opening ? As it was expressed in Chapter VII, that if the value of y = positive, then juice is really extracted by the feed opening. But likewise, if the value of y = negative, it is concluded in average that the feed opening of the respective mill does not extract any juice. The value of y also indicates the presence of slip when a rather high value is defined. Generally speaking a heavy slip is presence, if too many juice extracted by the feed opening compared to the juice extracted by the delivery opening. Beside of no extraction made by the feed opening when the value of y = negative, it also indicates in average that the feeding of the respective mill is less and not stable. The normal value of y is between 0.10 – 0.30. It means the juice volume extracted by the feed opening is about 10% – 30% from the volume of juice extracted by the delivery opening. Then it is suggested that the most extraction should due by the delivery opening to avoid the occurrence of heavy slip in a respective mill. The condition will be achieved when the ratio
The Computer Program Program
XII-8
Mill Material Balance
between feed and delivery work opening (i) actually sets referred to the value defined by the projection of the material balance balance (the Projection Program). d. Is there any deflection deflection made by the top roller ? Among the 3 (three) rollers in use, the top roller is attaining the most pressing work in a unit of mill (attaining the pressing due in the feed and the delivery openings). Because the top roller supported by two upper halves of the top metals, then a slight deflection will occur on the shaft and the roller shell as well. The roller shafts made of forged steel material, while cast iron or cast steel is for the roller shells. Based on the different materials, roller shell deflection should be intensely monitored to prevent the roller breakage during the course of milling. The different between the actual work opening (calculated) and the work opening when set, and then divided by the roller length will show the value of deflection made by the roller. The limit value of deflection (maximum) for the roller shell made of cast iron/steel is around 0.22%. If the average value of deflection exceeding the limit, it is definitively concluded that the roller works in danger. The occasion would not happen, if the setting of the respective mill done precisely according to the calculation made by the projection program of the material balance. Especially when the centers to center distances between the rollers were not checked during the setting of mills to prove its accuracy, or, if the roller lift (hydraulic lift) s ets exceeding or higher than the dimension determined by the calculation (the material balance). e. Everything related to bagasse Items evaluated in bagasse among other things are: §
#
The no-void density (d a). It is best when the value gradually increasing from mill 1 to the last mill.
§
#
The absorption ability factor (r). Its value should gradually decrea-sing from mill 1 to the last mill.
§
The value of normal absorption ability factor (r’) also gradually decreasing.
§
The bagasse percentage to cane (gat) gradually decreasing.
§
%pol (pa) and %Brix (b a) also gradually decreasing.
§
The dry matter (zk) is best when gradually increasing.
f. Everything about fiber The evaluation should be at least focused to the followings: §
The fiber index (c). The fiber index normally expressed in kg/dm 3 of the volume escribed by the delivery work opening is to know the fiber true density when pressed or milled under the rollers. If the value obtained from the calculation of mill material balance compared to the value from the table (see the Java Method of Mill Setting, E. Hugot third edition editi on 1986, page 201-203), then we’ll know the true capability of the roller shell material in use. The higher the value of fiber index, meaning the best material for the roller is and that has the character of building
The Computer Program Program
XII-9
Mill Material Balance
up raw grain surface. Therefore the value of its fiber index obtained from the calculation also indicates the capability of the respective mill. §
The fiber loading (q). 2
The fiber loading expressed in gram/dm of the roller surface is to know the rate of average fiber distributed to the roller surface during the pressing of cane or bagasse under the rollers. It is also to know the difference when compared to the value obtained from the table (see the Java Method of Mill Setting, E. Hugot, third edition 1986, page 201-203). For the mills driven by reciprocating steam engines, where the roller rotations decreasing from the first to the ensuing mills, the values of fiber loading gradually increasing. But it is not the case with mills driven by steam turbines or by electric motors. Steam turbines have nominal speed, where the efficiency could be achieved optimally. Thus for the mill tandem with steam turbine or electric motor drives, the rotation of the rollers should be set based on the nominal speed of the steam turbines or the electric motor respectively. When steam turbines used for the tandem, the fiber loading should refers to the capability of the normal 30” mills or it is usually called the reduced fiber loading (q’), whereas if the value lies between: Ø
120-130 gram/dm 2 is normal. It means the respective mill is sufficient when provided only with an ordinary feeder roller for the feeding device.
Ø
130-140 gram/dm 2, besides of feeder roller the respective mill also needs to be provided with a Donnelly chute to perform a reasonable feeding.
§
Ø
140-160 gram/dm 2, the mill needs to be provided with a light duty pressure feeder.
Ø
150-170 gram/dm , the mill needs to be provided with a heavy-duty pressure feeder.
2
The fiber percentage to bagasse (kf). The value gradually increasing from mill #1 to the ensuing and up to the last mill, but it should also be compared with its it s value normally achieved.
The Computer Program Program
XII-10
