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