Suitable type of motor for a lead oxide mill 1

[tito2004]

I need some advise about the type of motor for a lead oxide mill(similar to a ball mill). We need to move a 7000 pounds load, including mill weigth. Which is more recommendable a slip ring or a common induction motor and which would be the HP required? Thanks.
Tito

 

[DougMSOE]

If the atmosphere is explosive, suggest an induction motor of the squirrel cage type with a high locked rotor torque to get the mill started. However if your plant needs power factor correction, then capacitors may have to be used.
If non-explosive atmosphere then would suggest a synchronous motor that could be used as a power factor correction device if it is required. Wound rotor induction motor is probably not indicated, but the locked rotor torque is not known.
As for required HP, this will be dependent on the reduction gear used with the mill and the RPM of the motor and the mill, AND the inside diameter of the mill itself.
Need more info, at least the hints are here.

 

[GusD]

Hi tito2004 .

My previous experience with Rod Mills/Ball Mills was in a Copper Mine.I am not familiar with the specific concerns regarding equipment operating in the mining of Lead Oxide The equipment would have to be suitable for the location,whether IND Motor,Sync,WRotor or DC. Our plant used all Syncronous Motors for the Rod and Ball mills.THe choice of Sync motors,over other types,had to do with the large Hpower requirements.(40,000 hp)
With 4 Rod mills and 4 Ball mills ,5000HP each,It would require an enormous amount of Power Factor correction if
straight induction motors were used.
These large syncs were quite reliable and pretty well trouble "free". The very slow speed also helped.
As for the required HP to move the load ,it would be dependent on a lot of variables.Matching the drive to the load correctly is the most important factor.
OUr drives were brought to full speed disconnected from the load,once at full speed an air friction clutch was energized connecting the motor to the load.(smoked a little sometimes)

GusD

 

[jbartos]

Suggestion: It would be preferable to begin with the mechanical load characteristics. Then, simulation may be found useful to avoid the motor undersizing, oversizing, and improper motor speed toque characteristics. The site power distribution system needs to be included in the analysis to avoid unnecessary modifications.