The values are not linked with anywhere…..
2 4 R= 40 m 3 7 6
5 10 m
CONVEYOR PROFILE
500 m
1
20 m
8
9
CONVEYOR DESIGN by IS - 11592 : 2000 :
Material Lump Type Lump Size Type
Bottom Ash
Flowability / Material Characteristic Maximum Lump Size Capacity Bulk Density of Material
: C ρ
: :
300 mm 960 TPH 3 0.800 t/m
B KL
: :
1200 mm 4
Air Bone Factor
KAB
:
0
Abrasiveness Factor
KAS
:
2
Speed Factor Where, KV = ( KL + KAB + KAS ) Belt Speed Angle of Inclination Angle of Surcharge
KV
:
6
V δ ψ
: : :
Input Data & Calculation: Width of Belt Lump Size Factor
:
Angle of Repose Slope Factor Maximum Capacity of a Belt (for ρ=1.0 t/m3, V=1.0 m/s, K=1.00) Corresponding Values: Maximum Belt Capacity Trough Angle Belt Width Cross Sectional Area
K C
: :
C λ B A
: : : :
Selected Belt Width Actual Belt Speeds Belt Type
B V
: : :
3 m/s 14 ° 25 ° Over 35 ° and up to 40 0.91 439.56 t/h
464 20 1200 0.129
t/h ° mm m2
1.2 meter 2.84 m/s
As per IS 11592, Table 3
As per IS 11592, Table 6 As per IS 8730, Table 3 As per IS 8730, Table1
As per IS 11592, Table 9
As per IS 11592, Table 10 As per IS 11592, Table 7
CONVEYOR DESIGN by IS - 11592 : 2000 Peripheral Force on the Drive Pulley TE = (R + RS + RSP1 + RSP2 + RSL) Main Resistance R = f . L . g. [ mc + mr + (2 mB + mG). Cosδ] Artificial friction coefficient Conveyor length (distance between centers) Mass of revolving idler parts along the carrying side of the conveyor per meter Mass of revolving idler parts along the return
TE
:
17822 N
R
:
2717 N
f L mc
: : :
0.02 100 m 15 kg/m
mr
:
15 kg/m
mB mG
: :
7.729 kg/m 93.91 kg/m
δ
:
14 °
RS
:
2164 N
Ra
:
757.2 N
:
0.333 m /s
side of the conveyor per meter
Mass of belt per meter Mass of handled material on conveyor per meter mG = 1000.ρ.Q / V Slope angle of conveyor from horizontal line in the moving direction
Secondary Resistance RS = Ra + Rska + Rw + Rb Inertial and frictional resistance at the loading point and in the acceleration area between the Handled material and the belt Ra = Q . 1000 . ρ . ( V - V0 )
Volumetric Capacity Q Q= A.V.K V0 Handled material conveying speed component in the direction of belt motion Frictional resistance between handled material Rska and the skirt plates in the acceleration area
3
:
0 m/s
:
258.4 N
2 Rska = μ2.Q .1000ρ.g.l a (V+V0) 2 .b12 2 Interskirt Plate Width
b1
:
0.8 m
Acceleration length in loading area
la
:
0.765 m
μ1
:
0.6
μ2
:
0.5
Rw
:
610.5 N
2
la=
2
V - V0
2.g.μ1
Coefficient of friction between material and belt Coefficient of friction between material and skirt plate Wrap Resistance between belt and pulley
Rw = 9B 140+0.01.
Rw = 12B 200+0.01.
Tav
t
B
D
Tav
t D
B
Average Belt Tension in the Pulley Belt thickness
not to be calculated for drive pulley
for fabric carcass belt
for steel cord belt
Tav
:
17115 N
t
:
0.1 m
3E-05
Pulley Bearing Resistance
Rb
:
d Rb=0.005 Rv D Shaft diameter inside diameter d : Pulley diameter D : Rv : Vectorial sum of the two belt tensions acting on the pulley and of the forces due to the mass of the revolving parts of the pulley Special Resitance Rsp : Rsp = (Rsp1+Rsp2) = (Ri + Rsk + Rbc + Rp ) Resistance due to idler tilting Ri = g.Ci.μ0.Li (mB+mG) cos δ. sin i A constant coefficient of friction between carrying idlers and belts Angle of tilt of the idler axis with respect to a plane perpendicular to the longitudinal axis of the belt Length of installation equipped with tilted idler Resistance due to friction between Handled material and skirt plates
537.5 N
0.15 m 0.5 m 35835 N
Ri
:
1.51 N
Ci
:
0.5
μ0
:
0.35
i
:
2 °
Li
:
0.5 m
Rsk
:
84.49 N
l sk
:
1 m
Rbc
:
0.048 N
Al
:
2 0.1 m
μ3
:
0.6
Rp
:
1800 N
Ka RSL
: :
1500 N/m 11055 N
H
:
In case of carrying idlers equipped with three equal length ro
μ2.Q .1000ρ.g.l sk V2 b12
Length of installation equipped with skirt plates excluding Frictional resistance due to belt cleaners Rbc = Al . ρ . μ3 Area of contact between belt and belt cleaner Coefficient of friction between belt and belt cleaner Resistance due to friction at the discharge plough
Rp = B . Ka Scraping factor Slope Resistance RSL = mG.H.g Lift of conveyor between loading end and dicharge end
1E-10
1886 N
2
Rsk =
not to be calculated for driving pulley
: : : : : : : : : : : : : : : : :
12 m
CONVEYOR DESIGN by IS - 11592 : 2000 Φ T1
T2
30⁰ TE
Peripheral Force on the Drive Pulley Minimum Slack Side Tensile
TE
:
17822 N
T2min
:
8204.12 N
TE max
:
21386.4 N
ξ μ Φ
: : :
Tmin
:
1
T2 min≥ TE max
eμΦ - 1 Maximum Peripheral Force TE max= ξ . TE Drive Coefficient Coefficient of friction between drive pulley and belt Angle of Wrap Minimum Tensile force to limit the Belt Sag(Carrying Side)
1.2 0.35 3.67 radian 5191.08 N
Pc (mB+mG) g Tmin≥ 8S Pc : 1 Pitch of carrier idler or idler spacing on carrying side of the conveyor Tmin Minimum Tensile force to limit the Belt Sag(Return Side) : 592.076 Pr.mB.g Tmin≥ 8S Pr : 1.5 Pitch of return idler or idler spacing on return side of conveyor Maximum Allowable Belt Sag S : 0.024 h S= a adm Minimum Force required in slack side T2 : 8204.12 Tension of Tight Side T1 : 26026.11 Average Belt Tension at the pulley Tavg : 17115.1 Vectorial sum of the two belt tensions acting on the Rv : 35835 pulley and of the force due to the mass of the revolving parts of the pulley ={ (T1 * cos(δ) + T2 * Cos (Ѳ) )2 +(T1 * sin(δ) + T2 * sin (Ѳ) + W p )2 }1/2
Weight of Pulley
Maximum Operating Belt Tension Tmax = T1 = TE
ξ eμΦ - 1
-1
m N
m
N N N N
δ Ѳ Wp
: : :
14 ⁰ 30 ⁰ 5000 N
Tmax
:
-9617.87 N
See IS-11592, Table 15 See IS-11592, Table 16 210 °
:
Table 3: Maximum Lumps Sizes in relation to Belt Width
Belt Width 300 400 450 500 600 650 750 800 900 1000 1050 1200 1350 1400 1500 1600 1800 2000
Maximum Lump Size Uniform Size 75 75 75 100 125 125 180 180 200 260 280 360 380 380 410 410 460 500
Unsized 100 100 125 150 200 230 300 330 380 430 460 530 660 680 750 800 900 1020
Table 4: Lump Size Factor 6 4 Material Fine Grain to dust Granular Sized and Unsized
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
0
Lump Size
Lump Size Factor
Air Bone Factor
<10 mm
0
4
<25mm <20 percent of maximum permissible lump size
1
0
2
0
Quantity of Sized, largest Lump <60% in is <60 percent permissible of maximum Range permissible lump size
1 2
3
3
0
4
Largest lump does not exceed Unsized maximum permissible lump size Largest lump does not Sized, in exceed permissible maximum Range permissible lump size
4
0 5
4
0 6
Table 5: Abrasiveness Factor 16 2 Abrassiven ess
Type of Abrasivenes Material s Factor Cereal Grains Wood Chips Wood Pulp Fullers Earth Non Abrasive Flue Dust 1 Soda Lime Char Loam Sand Ground Gravel Run of bank sand and gravel Mildly 2 Slate Abrasive Coal Salt Sand stone Slag Spar Abrasive 3 Limestone Concentrates Pellet Iron Ores Tacontie Jaspar Heavey Mineral Very Flint Rock 4 Abrasive Glass cullet Granite Traprock Pyrites Sinter
1 2 3 4 5 6 7 8 9 10 11 12 13
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
Abrasive
33
Coke
IS 8730 : 1997 Table 1: Class based on Flowability, Angle of Sucharge and angle of repose 22 4 25 Over 35 and up to 40
Class
Surchage Angle
Angle of Repose (degree)
Flowability
1
5
Over 0 and up to 20
Very free flowing
2
10
Over 20 and up to 30
Free Flowing
3
20
Over 30 and up to 35
Average Flowing
4
25
Over 35 and up to 40
Average Flowing
5
30
Over 40
Sluggish
Material Characteristic Very Free Flowing -uniform size -Very small round particle -very wet -or very dry -like silica sand -cement -wet concrete, etc. Free Flowing -rounded -dry polished -medium wight -like whole grain -beans Average Flowing -irregular -granular or lumpy -medium weight -anthracite coal -cotton-seed meal -clay, etc. Average Flowing -bituminous coal -stone -most ores, etc Sluggish -irregular -stringy -fibrous -interlocking -like, wood chips -bagasse -tempered foundry sand, etc.
.
Table 6: Maximum Recommended Belt Speed (m/s)
Speed Factor 1 2 3 4 5 6 7 8
Belt Width in mm up to 500 600 to 650 750 to 800 950 to 1050 1200 to 2000 2.5 3 3.5 4 4.5 2.3 2.75 3.2 3.65 4.12 2 2.38 2.75 3.15 3.55 2 2.38 2.75 3.15 3.55 1.65 2 2.35 2.65 3 1.65 2 2.35 2.65 3 1.45 1.75 2.05 2.35 2.62 1.45 1.75 2.05 2.35 2.62 Lump Size 300 11 1 300 7
Lump Type Uniform Size Unsized Belt Width Speed Factor: Velocity
Belt Type Fabric Carcass Belt Steel Cord Belt
1200 6 3
280 1050 300 750
0.93 1200 1.0 800
For belt size above 2000mm 2.5m/s velocity has been considered.
1
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33
.
Table 7: Maximum Section of the Handled Maaterial in M2 for Triple Roller Troughed Belt 1200 25 20 0.129 Trough Angle in Degree
Belt Width (in mm)
Surcharge Angle
500
0 10 20 30 0 10 20 30 0 10 20 30 0 10 20 30 0 10 20 30 0 10 20 30 0
20 0.009 0.014 0.018 0.023 0.018 0.026 0.034 0.042 0.027 0.04 0.053 0.067 0.047 0.067 0.087 0.109 0.07 0.098 0.129 0.16 0.098 0.138 0.179 0.221 0.13
25 0.012 0.016 0.02 0.025 0.022 0.029 0.037 0.045 0.034 0.046 0.059 0.072 0.058 0.077 0.096 0.117 0.085 0.113 0.142 0.172 0.12 0.158 0.197 0.238 0.159
30 0.013 0.18 0.022 0.026 0.026 0.033 0.04 0.048 0.04 0.051 0.063 0.076 0.067 0.085 0.104 0.134 0.099 0.126 0.153 0.182 0.139 0.175 0.213 0.253 0.185
35 0.015 0.019 0.023 0.027 0.029 0.036 0.043 0.05 0.045 0.056 0.067 0.079 0.076 0.093 0.111 0.129 0.112 0.137 0.163 0.19 0.157 0.191 0.22 0.264 0.208
40 0.017 0.021 0.024 0.028 0.032 0.038 0.045 0.052 0.05 0.06 0.071 0.082 0.083 0.099 0.116 0.134 0.123 0.146 0.171 0.196 0.171 0.204 0.237 0.272 0.228
45 0.018 0.022 0.025 0.029 0.034 0.04 0.046 0.053 0.054 0.063 0.073 0.084 0.089 0.105 0.12 0.136 0.132 0.154 0.176 0.2 0.184 0.214 0.245 0.277 0.244
10 20
0.182 0.236
0.209 0.261
0.233 0.282
0.253 0.3
0.27 0.314
0.283 0.324
30
0.293
0.315
0.334
0.349
0.36
0.366
0
0.167
0.203
0.237
0.266
0.292
0.313
650
800
1000
1200
1400
1600
1800
2000
2200
2400
2600
2800
10
0.233
0.268
0.298
0.324
0.346
0.363
20 30 0 10 20 30
0.302 0.374 0.207 0.29 0.376 0.465
0.334 0.403 0.253 0.332 0.415 0.501
0.361 0.427 0.294 0.37 0.448 0.53
0.384 0.446 0.331 0.403 0.476 0.554
0.401 0.46 0.362 0.429 0.49 0.571
0.414 0.468 0.388 0.45 0.514 0.581
0 10 20 30 0 10 20 30 0 10 20 30 0 10
0.257 0.357 0.461 0.569 0.303 0.423 0.547 0.677 0.36 0.502 0.648 0.801 0.413 0.578
0.311 0.408 0.508 0.613 0.368 0.484 0.604 0.729 0.439 0.575 0.716 0.863 0.505 0.663
0.363 0.455 0.549 0.649 0.428 0.539 0.653 0.772 0.51 0.64 0.774 0.914 0.585 0.727
0.408 0.494 0.584 0.677 0.482 0.586 0.694 0.806 0.573 0.695 0.822 0.953 0.66 0.803
0.446 0.527 0.61 0.697 0.528 0.625 0.725 0.83 0.628 0.741 0.859 0.982 0.721 0.885
0.478 0.552 0.629 0.71 0.566 0.656 0.748 0.845 0.672 0.777 0.885 0.999 0.774 0.897
20 30
0.749 0.928
0.827 0.998
0.894 1.063
0.95 1.104
0.993 1.137
1.025 1.158
500 650
0.018 0.034
800 1000 1200 1400 1600
0.053 0.087 0.129 0.179 0.236
1800 2000 2200 2400 2600 2800
0.302 0.376 0.461 0.547 0.648 0.749
Table 8: Maximum Section B of the Handled Material in m2 fro Two Equal Idler Troughed Belts and for the Flat Belts .. Belt Width Surchage (mm) Angle 300
400
500
650
800
1000
1200
1400
Two Idler Troughed Belts Trough Angle 15
20
Flat Belt
25
0 10 20 30 0 10 20 30 0 10 20 30 0 10 20 30 0 10 20 30 0 10 20 30 0
0.005 0.008 0.01 0.014 0.01 0.014 0.018 0.023 0.017 0.025 0.033 0.042 0.027 0.039 0.052 0.065 0.044 0.064 0.084 0.106 0.066
0.007 0.01 0.012 0.015 0.012 0.017 0.021 0.025 0.023 0.03 0.038 0.045 0.036 0.047 0.059 0.071 0.057 0.076 0.095 0.116 0.085
0.009 0.011 0.013 0.016 0.015 0.019 0.023 0.027 0.027 0.037 0.041 0.048 0.042 0.053 0.064 0.076 0.069 0.86 0.104 0.123 0.102
10
0.095
0.112
0.127
0.03
20
0.125
0.14
0.153
0.062
30
0.156
0.17
0.181
0.095
0
0.001 0.002 0.004 0.002 0.005 0.008 0.004 0.009 0.014 0.008 0.016 0.025 0.013 0.026 0.04 0.021 0.042 0.065
1600
10
0.042
20
0.086
30 0 10 20 30
0.132 0.56 0.114 0.175
Table 9: Slope Factor K 14 0.91 Conveyor Inclination 2 4 6 8 10 12 14 16 18 20 21 22 23 24 25 26 27 28 29 30
Slope Factor K 1 0.99 0.98 0.97 0.95 0.93 0.91 0.89 0.85 0.81 0.78 0.76 0.73 0.71 0.68 0.66 0.64 0.61 0.59 0.56
Table 10: Maximum Capacity of a Belt Conveyor in tonnes/hour 1200 25 439.56 Belt Width Surcharge (in mm) Angle 500
650
800
1000
1200
1400
1600
Trough Angle in Degree
0 10 20 30 0 10 20 30 0 10 20 30 0 10 20 30 0 10 20 30 0 10 20 30 0
20 35 51 67 84 56 94 123 153 100 145 192 241 172 242 315 392 252 355 464 576 352 497 644 795 468
25 43 58 74 90 80 107 135 165 123 168 212 260 209 277 348 421 307 407 511 619 432 569 709 857 572
10 20
655 849
752 939
30
1054
1134
601
731
1800
0
839
965
1087
1202
1346 745 1044 1359 1674
1451 911 1195 1494 1803
1
2
67 123 192 315 464 644 849 1087 1359
74 135 212 348 511 709 939 1202 1494
10
2000
500 650 800 1000 1200 1400 1600 1800 2000
20 30 0 10 20 30
0 0 0 0 1 1 1 1 1
Belt Conveyor in tonnes/hour 1 20
Table 11: Mximum Capacity of a Belt Conveyor in to 464
Trough Angle in Degree 30 50 65 80 96 93 119 146 174 144 186 229 274 243 308 374 446 357 453 551 655 500 630 767 911 666
35 56 70 85 100 106 130 156 182 163 203 244 287 274 336 339 464 403 493 587 684 565 687 792 950 749
40 62 75 89 103 116 139 163 188 180 217 255 296 301 359 417 482 443 525 615 705 615 734 853 979 820
45 67 79 92 105 125 146 169 192 194 229 265 302 323 378 432 489 475 554 633 720 662 770 882 997 878
839 1015
911 1080
972 1130
1019 1166
1202
1256
1296
1317
853
957
1051
1127
Two Idler Troughed Bel Trough Angle 15
Belt Width (mm)
Surchage Angle
300
0 10 20 30 0 10 20 30 0 10 20 30 0 10 20 30 0 10 20 30 0 10 20 30 0
21 30 40 50 36 53 67 84 64 96 121 151 99 143 188 236 161 232 304 381 238
10
342
20
450
30
561
400
500
650
800
1000
1200
1400
0
1073
1166
1245
1307
10
1299
1382
1443
1490
20
1537 1058 1332 1613 1908
1605 1191 1451 1713 1994
1656 1303 1544 1793 2055
1685 1397 1620 1850 2091
3
4
5
6
80 146 229 374 551 767 1015 1299 1613
85 156 244 339 587 792 1080 1382 1713
89 163 255 417 615 853 1130 1443 1793
92 169 265 432 633 882 1166 1490 1850
1600
30 0 10 20 30
city of a Belt Conveyor in tonnes/hours
Two Idler Troughed Belts Trough Angle 20 25
Flat Belt
5 10.5 15.8 27 36 45 55 46 61 76 92 83 109 137 165 129 171 214 258 208 275 344 417 306
33 41 49 58 55 69 83 98 98 123 148 175 154 193 233 274 248 310 374 443 367
403
457
111
504
551
225
612
651
345
10 20.5 31 17 34 52 30 60 93 47 95 146 75 154 235
153
311
475 201 410 630
…
CONVEYOR DESIGN by IS - 11592 : 2000 Peripheral Force
TE
:
17822 N
Operating Power Requirement on Drive Pulley TE . V PDP = 1000 Absorbed Power T .V ( Rwd + Rbd )V PA = E + 1000 1000
PDP
:
50.606 kW
PA
:
53.866 kW
Wrap resistance between belt and pulley for drive pulley
Rwd
:
610.5 N
Pulley bearing resistance for drive pulley
Rbd
:
537.5 N
Motor Output Power (shaft) PA PM = η1 Efficiency of various trasmission element
PM
:
56.7 kW
η1
:
0.95
Additional power required due to tripper T .V ( Rwd + Rbd )V Pa = E (1+ntβ) + 1000 1000
Pa
:
Number of trippers Factor for extra power for each tripper
nt β
: :
See IS-11592 table 12
79.17 kW
5 0.1
See IS-11592 table 13or14
CONVEYOR DESIGN by IS - 11592 : 2000 Idler Spacing (Normal Circumstances) For Carrying Side Belt Sag for Considered Idler Spacing Pc (mB+mG) g S= 8.Tmin For Return Side Belt Sag for Considered Idler Spacing Pr . mB .g S= 8.Tmin Minimum Tensile force on Belt between Spacing
Transition Distance x = 0.707y
E ΔT
:
1200 mm
S
:
0
S
:
0
Tmin
:
x
:
m
:
m
See IS:11592, Table 17
N Selected Idler Spacing is Safe
1/2
Vertical Distance Between Belt Rise or y lowers during transition B sinλ When pulley is in line with y= 3 top centre idler roller B sinλ y= 3 When pulley is elevated Belt Modulus E ΔT Induced Belt Edge Stress in the Transition
: : : : : : : : : : : : : : : : : : : :
500 N/mm N/mm See IS:11592, Table 18
CONVEYOR DESIGN by IS - 11592 : 2000 Selection Of Belt Factor of Safety Full Thickness Tensile Strength of Belt *Select the Belt Type
Factor of Safety:
Selectecd Belt Belt Thickness
t
Grade of Cover Thickness Conveyor Carrying Side Thickness Belting Pulley Side Thickness Elevator Carrying Side Thickness Belting Pulley Side Thickness Diameter of Pulley Driving Pulley and Pulley Exposed to high tension Snub Pulley in the return run under lower tension Bend Pulley for a change of Direction of the belt of less then 30°
D
: :
10 -96178.663 N
: :
Belt Type m
: : : : : : : : : :
N17 2.5 1.0 1.5 2.5
: : : : : : : : : :
mm mm mm mm
mm mm mm
See IS-1891 (Part1) Annex A
See IS-1891(Part-1) Table 8 and IS 3181 for PVC Belt
Factor of Safety: Textile Belt Steel Cord Belt
Textile Belt: 9 to 12.5, Generally 10 Steel Cord Belt: 7 to 10, Generally 7
Belt Type Textile Rubber Belt PVC Belt Steel Cord Belt
Textile Rubber: 1.0 to 3.0 mm PVC belt: 0.8 to 1.2 mm Steel cord Belts: Min. 4.0mm
M24 N17 N17 Synthetic
DETERMINATION OF CONVEYOR SECTIONAL AREA AS PER C.E.M.A l1 F
B G
A
C
a
b c m f
l
r j
a
a
D TYPICAL CONVEYOR CROSS-SECTION a = angle of surcharge , degrees = angle which the surface of the material assumes with the horizontal while the material is at rest on a moving conveyor belt O
= 25 for bituminous coal or lignite b = angle of the idler roll , degrees b = width of belt , inches Standard edge distance , c =0.055b + 0.9 , inches b = l + 2m + 2c m = 0.2595 x b -1.025 l = 0.371 x b + 0.25 Cross-sectional area of material on conveyor , sq. in A = [ 0.371b + 0.25 + (0.2595b - 1.025) cos b ] x [ ( 0.2595 [ ( 0.2595b b -1.025 - 1.025) ) sin bsin ] b] + (π a/180 - sin 2a / 2 ) X [ { 0.1855 b + 0.125 + (0.2595 b - 1.025 ) cos b}/ sin a ] BELT WIDTH
mm 800 450 500 600 750 900 1000 1050 1200 1350 1500 1800 2100 2400
in 32 18 20 24 30 36 40 42 48 54 60 72 84 96
a
b
A
deg. 25 25 25 25 25 25 25 25 25 25 25 25 25 25
deg. 20 20 20 20 20 20 20 20 20 20 20 20 20 20
sq. ft 0.673 0.188 0.239 0.359 0.585 0.866 1.084 1.202 1.592 2.037 2.537 3.702 5.085 6.688
A
Belt
sq.m Speed m/s 0.063 0.84 0.017 2 0.022 1.2 0.033 2 0.054 2 0.08 2 0.101 1.83 0.112 2 0.148 1.25 0.189 2 0.236 2 0.344 2 0.472 2 0.621 2
NB : Results are verified against CEMA's Publication
Bulk. Dnst. 3
Kg/m 800 800 800 800 800 800 800 800 800 800 800 800 800 800
2
Capacity
l
l
Te/Hr. 151.2151 100.6383 76.7525 192.2602 313.2048 463.4721 530.6457 643.0621 532.4842 1090.21 1357.768 1980.852 2721.226 3578.892
in 12.12 6.93 7.67 9.15 11.38 13.61 15.09 15.83 18.06 20.28 22.51 26.96 31.41 35.87
mm 307.90 175.97 194.82 232.51 289.05 345.59 383.29 402.13 458.67 515.21 571.75 684.83 797.92 911.00
Detail Proof As = area of surcharge , sq. in ( area ABC ) Ab = base trapezoidal area , sq. in (area AFGC) l = length , smaller edge of trapezoidal area , inch l 1 = length , larger edge of trapezoidal area , inch j = height of trapezoidal area , inch m = slant length of trapezoidal area , inch r = radius of surcharge angle, inch f = horizontal projection of slant side of trapezoid , inch c = edge distance , edge of material to edge of belt ,inch b = width of belt , inch Standard edge distance c = 0.055 b + 0.9 inch Ab = 0.5 (l + l 1 ) x j b =l +2xm +2Xc l1 = l + 2 x f f = m x cos b l = 0.371 x b +0.25 c = 0.055 x b + 0.9 Solving , m = 0.2595 x b -1.025 j = m x sin b 2
Area of whole sector (ABCD) = π x r x 2 x a /360 2
Area of triangle (AECD) = r x 0.5 x sin ( 2 a) 2
Surcharge area , As = r x {π x a / 180 - 0.5 x sin ( 2 a) } r = 0.5 x l 1 / sin a Total area in sq. ft. , At = ( Ab + As ) / 144