Inoculation system ends Neenah's search for reliability.

Neenah Foundry Co., Neenah, Wis., had been on a quest for a more reliable inoculation system when it discovered the Koins automatic inoculation system (AIS) at the 2005 CastExpo in St. Louis.

"We've been trying to get as foolproof of an inoculation system as we could get," said Frank Headington, corporate vice president-technology for Neenah Foundry, a gray and ductile iron green sand casting facility. "The system from Koins looked simple but still featured everything we were looking for."

The AIS from Koins consists of a stainless steel, heat-protected injection unit that is equipped with a conveyor controlled by a servo drive (a control system that converts a small mechanical motion into one requiring greater power), making it possible to adjust the dosing of the inoculant to exact requirements. An electric servo motor controls the speed of the rotation of the screw conveyor and provides feedback to the controller, allowing the unit to measure the preselected feed rate (auger rotation speed) with precision. Inoculants are delivered between 1 and 30 g/sec.

"We were looking for reliability," Headington said. "This system has checks and balances built in that result in greater reliability and accuracy."

Headington said the system also takes into account the effect of changing pouring rates by self-tuning back pressure when the g/sec, setpoint is changed. It also is easier to maintain than the previous system, and maintenance costs are 75% lower. To change inoculants, maintenance personnel simply switch the inoculant magazine, as opposed to cleaning out the whole system.

Additionally, the dosing unit provides automatic error checking using a variety of sensors to check for:

* low level in the hopper;

* insufficient air supply;

* feeder screw operation;

* no inoculation is fed;

* incorrect feed rate;

* incorrect injection pressure due to partial plugging of injection pipe.

Visit www.koins-ltd.com for more information.