May, 1996

Superior Controls was recently asked to implement an automated Ice Cream Batch control system for manufacturing facilities in Ohio and Massachusetts. The challenge of this implementation was to provide complete installation and start-up in one weekend.

The existing system at each plant consisted of a 10-year-old PLC and a 20-25 year-old large control drum sequences. For those of you too young to know, mechanical control drums were cylindrical devices that turned like a clock, activating and deactivating contacts that controlled the appropriate field equipment such as pumps, valves, etc.

Superior Controls provided an Allen-Bradley PLC on a panel insert, prewired to accommodate approximately 160 field instrument signals. A PC was configured with Intellution's FIX package and Visual BASIC that provides the operator with graphical displays, recipe selection, batch reports, and manual override capabilities.

To automatically produce a tasty delight like Chocolate Swirl or Fresh Cookie Dough ice cream, the FIX package was preconfigured with all of the ice cream recipes. When activated, the appropriate recipe was appropriate recipe was downloaded to the Allen-Bradley PLC which, in turn, added the correct amounts of milk, cream, fructose, corn syrup, etc. In addition, CIP or "Clean In Place" sequences were programmed into the PLC to automatically clean the valves, pumps, and tanks used to create the most recent batch of ice cream.

Both ice cream facilities were manufacturing at full capacity and could afford only a weekend of downtime for the conversion. On a Friday, Superior Controls' engineers and technicians began disconnecting and carefully labeling the field wiring from the old system of the Massachusetts facility. Working through the night, they removed the old equipment and began installing, rewiring and attaching the new control system. This system absolutely, positively had to function flawlessly for Monday morning production or the whole plant would be shut down.

Saturday was spent wiring the new system and by Saturday night the PLC and PC were ready for production test runs. Due to the weeks of in-house testing and simulation at Superior Controls, the PLC/PC logic worked flawlessly. Recipes, CIP sequences, reports, and alarms were tested all day Sunday. The result: Monday morning production began on schedule.

Three weeks later in Ohio, the second ice cream facility was just as successfully converted over a weekend. Doug Brenner, senior project engineer at Superior Controls, says, "I've acquired a new taste for ice cream. I plan to savor all the different recipes this summer." To celebrate, Superior Controls threw an ice cream party, of course, for employees and clients.