Motor preferred for kiln drives is usually
Right Answer is:
Any of the above
Kiln drives: The rotary kiln is an indispensable part of a cement plant. The rotary kiln drives depend upon the type of cement-making process (wet or dry). These are, in general, tubular tilted from the horizontal position with a ring fitted around them. This ring gear engages with one or two pinions. A variable-speed motor drives the pinion.
The requirements of a kiln motor are the following:
- Power requirement is very high
- The speed control ratio is 1:10. Very low creeping speeds of 1 rpm may be required.
- Starting torque should be in the range of 200 to 250% of full load torque.
- The acceleration of the drive should be completed in about 15 s.
- For small periods an overload capacity of 200-250% may be required.
- The motor must have suitable control for inching and spotting during maintenance.
The motors that meet the above requirements are as follows:
- A.C. motors with speed control.
- Slip ring induction motor.
- Ward Leonard controlled the D.C motor.
- Three-phased shunt-wound commutator motor.
- Cascade controlled A.C. motor.
- D.C. motor with transformer step switch control.