16 Ball Filling Degree & Mill Calculation

Annex 16.1

Mill calculation Plant :

Date :

Mill

Visa :

:

Mill Dimensions Diameter

D

5.00

[m]

Length

L

16.00

[m]

Motor power (inst.)

P

5,700

[kW]

L/D - Ratio

l

3.2

[-]

Compartment lengths

L1

36

[%]

L2

64

[%]

Data

1.Comp. Di

4.80

4.83

[m]

Internal length

Li

6.40

11.20

[m]

Filling degree

f

22.0

32.0

[%]

Spec. media weight

r

4.40

4.60

[t/m3]

Mill speed

n

15.0

Drive efficiency mech.

h

0.960

[-]

Drive efficiency electr.

h

0.950

[-]

Mill throughput

G

155

Fineness product

Blaine

3,800

Residue

[min-1]

[t/h] [cm²/g] [%] 32 [µm]

Relative mill speed

%n crit

Factor

c

0.250

0.212

[-]

Media weight

Q

112.1

302.1

[t]

Motor power abs.

P mec

2,014

4,640

[kW]

Spec. energy consumption

E sp

13.0

29.9

Media weight total

Q tot

414

Motor power mech. abs.

Pmec

6,931

[kW] motor shaft

Motor power electr. abs.

P el

7,296

[kW] electr. counter

Spec. energy consumption

E sp

47.1

[kWh/t]

Energy utilization

w

22.4

[cm²/J]

77.8

Filling Degree Calculations Mill

Internal diameter

1.Comp.

[%]

[kWh/t]

[t]

2.Comp.

Di

4.80

4.83

[m]

Free Height

h

3.20

3.05

[m]

In / Outlet

Diameter

d

1.50

1.25

[m]

Filling Degree

Present

f pres.

29.2

33.5

[%]

Maximum

f max.

30.4

33.7

[%]

0.67

0.63

[-]

3.15

3.04

[m]

H/D - Ratio Free Height

CMCALC2.XLS

2.Comp.

Internal diameter

max.

Ver.2.0/PWi/05.07.2001

Holcim Group Support Ltd / CTS

Annex 16.2

Fig.4 : Filling degree f in function of free height h above grinding media charge h D D

0,75 Di = Mill diameter 0,70

0,65

filling degree [%]

0,60 20

25

30

35

Fig.5 : Alternative way to determine the free height h=

Di + d 2

+ h'

Kma 5.1.99

Tube Mill Dimensioning CC-99003.dsf

h