ball filling degree mill calculation

Annex 16.1  

CMCALC2.XLS Ver.2.0/PWi/05.07.2001 Holcim Group Support Ltd / CTS

Mill calculation

Plant : Date :

Mill : Visa :

Mill Dimensions

Diameter D 4.20 [m]

Length L 13.00 [m]

Motor power (inst.) P 3,550 [kW]

L/D - Ratio 3.1 [-]

Compartment lengths L1 21 [%]

L2 79 [%]

Data 1.Comp. 2.Comp.

Internal diameter D i 4.08 4.08 [m]

Internal length L i 2.70 10.02 [m]

Filling degree f 28.8 25.6 [%]

Spec. media weight 4.60 4.60 [t/m3]

Mill speed n 15.8 [min-1]

Drive efficiency mech. 0.960 [-]

Drive efficiency electr. 0.950 [-]

Mill throughput G 145 [t/h]

Fineness product Blaine 3,700 [cm²/g]

Residue [%] 32 [µm]

Relative mill speed %n crit 75.4 [%]

Factor c 0.231 0.230 [-]

Media weight Q 46.8 154.3 [t]

Motor power abs. P mec 696 2,286 [kW]

Spec. energy consumption E sp 4.8 15.8 [kWh/t]

Media weight total Q tot 201 [t]

Motor power mech. abs. Pmec 3,107 [kW] motor shaft

Motor power electr. abs. P el 3,270 [kW] electr. counter

Spec. energy consumption E sp 22.6 [kWh/t]

Energy utilization w 45.6 [cm²/J]

Filling Degree Calculations 1.Comp. 2.Comp.

Mill Internal diameter Di 4.08 4.08 [m]

Free Height h 2.76 2.76 [m]

In / Outlet Diameter d 1.40 1.40 [m]

Filling Degree Present f pres. 28.0 28.0 [%]

Maximum f max. 28.6 28.6 [%]

H/D - Ratio 0.68 0.68 [-]

Free Height max. 2.74 2.74 [m]

Annex 16.2

CC-99003.dsf

Kma 5.1.99

Tube Mill Dimensioning

h

Di = Mill diameter

20 25 30 35

filling degree [%]

h

D

Fig.5 : Alternative way to determinethe free height

Fig.4 : Filling degree f in function of freeheight h above grinding media charge

0,75

0,70

0,65

0,60

h =Di + d

2 + h'