Industrial Automation : VFD In Jaw Crusher Applicatoin

Now a days VFDs are quite often used in Crusher/Mining industry. Here in this post the use of VFD in crusher application especially in the case of Jaw crusher is being mentioned.
in rock crusher plants induction motors are used in

• JAW CRUSHER : often coined as primary
• Cone Crusher : often coined as secondary
• Screen
• Conveyors
• Vibrators   : often coined as feeder motors
• lube pumps
• slurry pumps

For all of the above mentioned loads, now a days VFD is used. For each load characteristics are different.

JAW CRUSHER

Here as you can see from the above animated picture, the size of the rock , hardness varies by big margins, and hence heavily fluctuating load is there
the entire torque is provided by the giant flywheel attached.

Operating Strategies
Since the load is continuously varying, there will be situations where the rock get stuck and the drive needs to be under inching/jogging mode and operator has to jog the drive forward and reverser a few times to clear the rock out.

also there will be many a occasions where the motor current limit will be exceeded.

I  have seen in many occasion where the drive supplier provide a higher rating drive to ensure failure free operation. but its unnecessary

In the case of jaw crusher vfd you have to ensure follow things
 

• VFD always should be configured in vector/torque control mode

 

• Crusher sites are often dusty, so ensure a good enclosure of higher IP rating

 

• Check whether the motor is of inverter duty or not, always keep an eye on motor temperature

 

• If supply for VFD is from Diesel Generator, then verify whether the diesel generator is sized so that its able to meet all the peak load conditions appearing, please ensure no drop in voltage is taking place in that case.

 

• When designing a panel do put option for jog forward and reverse, provision for monitoring load current and also remote control desk.

 Setting relevant parameters for drive

when configuring the drive on vector mode ensure

proper motor data identification is performed
do cross check the upper and lower torque limits sets
ramp times set
check the current limit set
do all the relevant optimization sequence available in the drive so that maximum performance is available
do check the response of drive in the event of fault or power dip or abnormal condition

and most important do explain the working, purpose and operating of drive to the concerned operator because often unawareness is what leads to disasters

 In the next post i shall put the drive performance curves, typical application example for crusher related case