where Q = Mill Capacity in TPH q = Specific Mill Capacity
40 Kg/Kwh Kg/Kwh
a=Bond's Work Index vs Grindability From Table (III) CLICK HERE TO VIEW TABLE(III) b =Correction Factor For Fine Grinding From Table (ii CLICK HERE TO VIEW TABLE (II) c = Correction Index For Mill Type From Table (I) CLICK HERE TO VIEW TABLE(I) 3
v = Volume of Mill in m d1= Diameter of Mill t = Mill Liner thickness d = Effective Diameter of Mill in Metre G = Grind Grindin ing g Medi Media a Load Load
v*0. v*0.3*d 3*dens ensit ity y
ENTER THE VALUES :
b)
Effective Diameter of Mill Effective Length of Mill Volume Of Mill Density of Material Grinding Media Load SQRT v*d*g
2.7 2.7 Metr Metre e 5.4 5.4 Metr Metre e 30.9 30.917 171 1 M3 4.5 40.64 58.2449
Mill Capacity =
29.4647 TPH
Drive Power w (ne (net) t)
0.51 0. 515* 5*G* G*N* N*D D*U *U*a *a
Where W = Power in Kw G = Grinding Media Load N = Mill RPM
40.6 40.64 4 Tonn Tonne e 19 RPM
1.21 1.2 1.3 30.9 30.917 171 1 M3 2.8 0.1 0.1 Metr Metre e 2.7 2.7 Metr Metre e
2.7 Metre
D = Diameter of Mill in Met U = Torque Factor
0.73
a = Aim Of Gravity
0.6
w (net) c)
470.28 Kw.
Hot Air Requirement Assuming 28 % Media Filling for air calculation Free area of air fl 4.12228 M2 Air Velocity through the Mi = * 60 Air Flow Rate
3 M/s at NTP
Free Cross Sectional Area 4.12228 M2 Air Flow Rate = Providing 10% Extra than
742.01 NM3/Min. 816.211 NM3/Min.
At 90 Degree Cels 1085.29 M3/Min at 90 Degree Celsius 65117.5 M3/Hour at 90 Degree Celsius
d)
Hot Air Requirement
29.4647 TPH Mill Capacity = 6% to 1% Moisture Removal = Moisture To be Removed = 1.76788 TPH Heat Required = Moisture To Be Removed per Kg * Latent Heat Of Evapo 2209856 KCalSec/Hour Mass of Hot gas required mass x specific heat capacity x change in tempe mass * 0.24 *(300-90) 2209856 mass = 43846.3 Kg/hour 33910.6 Nm3/hour 71174.9 M3/Hour at 300 Degree celsius
e)
Volume at Mill Ou 90 Degree Celsius Air Flow Through mill (10 % margin 816.211 NM3/Min Water Vapour due to evaporation of Mass/Volume Of W ater At 90 Degree 2956.33 M3 at 90 Degree Celsius Total Air Flow at the outlet 68073.8 M3/ Hour at 90 degree celsius.
f)
44248 M3/Hour At 90 Degree Celsius Consider 65 % to bag Filte 41810.1 M3/Hour At 70 Degree Celsius Bag Filter Capaci 41810.1 M3/Hour At 70 Degree Celsius Taking 10 % Extra for Fan 45991.1 M3/Hour At 70 Degree Celsius Taking a Pressure drop of 150 -200 mm of hg Hence bag filter f 45991.1 M3/Hour At 70 Degree Celsius Static Pressure = 250 mm
g)
Recirculation Air = 0.35 xTotal air flow at the outlet of Mill 22791.1 M3/Hour At 70 Degree Celsius
h)
I D Fan Capacity 65117.5 M3/Hour At 90 Degree Celsius Static Pressure of I D Fan Pressure drop across mill 180 mm across Grit Seper 160 mm Twin Cyclone = 150 mm 50 mm Ducting = Total Pressure Dr 540 mm Required Static Pressure = 600 mm
