Corn shakes
15 Jan 2000
Replacement of a star/delta starter with a variable speed drive on a breakfast cereal mixer has reduced maintenance costs by over 80 per cent. Violent vibrations caused regular gearbox failures. In its place is an 11kW ACS 600 AC drive with direct torque control (DTC) from ABB Industrial Systems.
The 11kW star/delta starter rotated the vessel but could not control the acceleration or deceleration of the spinning load or the rapid changes in torque required to turn the container as the cereal shifted from one end to the other. These load change created violent oscillations that were transmitted back through the gearbox causing failure every six months.
Parmley Graham loaned the factory the ABB drive to prove that it would work. `This is something that we can do for customers who need convincing that they can get the result they want with AC drives,' explains Glen Hickman, sales engineer at Parmley Graham.
