Ducts Velocity M/Sec
Bag house to fan 16-18
Chimney 10-12
VRM Coal Mill Circuit
Hot Air duct to Mill Inlet 16-18
Mill Outlet to Bag Filter 16-18
Bag filter to fan 16-18
Chimney 10-12
VRM Cement Mill Circuit
Hot Air duct for Mill Inlet 16-18
Mill Outlet to Bag house 16-18
Bag house to fan 16-18
Chimney 10-12
Above norms for the ducting design are for the plant running at rated capacity.Plant can also operate with lower velocities as per our present experience at one
of our unit giving lower production consistently as shown in table below.
Conclusion
Based on the above data, ducts could be sized for lower velocity than design
norms at the engineering stage of a project resulting in lower pressure drops and
hence lower power consumption.
Operating Velocity Vs Design Velocity
S. N. Section UOM Design Data Operated Data % Loading
1 Kiln feed TPH 300 160 0.53
2 Clinker TPD 4500 2400 0.53
3 Down comer Velocity m/sec 16.4 9.75 0.59
4 Kiln Riser Duct m/sec 29 4.67 0.16
5 TAD Velocity m/sec 30 6.69 0.22
6 Precalciner m/sec 12.1 2.44 0.20
7 Riser 2-1 m/sec 9.3 4.88 0.52
8 Riser 3-2 m/sec 9.6 4.4 0.46
9 Riser 4-3 m/sec 10.3 4.4 0.43
10 Riser 5-4 m/sec 11.5 4.4 0.38
11 Riser 6-4 m/sec 12.2 4.4 0.36