Eric Schaefer
Breakfast Cereals and How They are Made, Second Edition
Pages 477-506
DOI: https://doi.org/10.1094/1891127152.013
ISBN: 1-891127-15-2
Abstract
The breakfast cereal industry uses a collection of diverse processes that require different methods of control. These include discrete, continuous, and batch functions. Discrete functions are of the on/off type such as packaging and related processes. Functions that do not start/stop, such as baking or frying, are considered continuous. Batching systems combine both the discrete and the continuous, and include such operations as dry ingredient mixing and syrup preparation.
Regardless of the type of process, the production of quality breakfast cereals is dependent upon process control. In the past, process control depended primarily upon operator expertise. However, the introduction of computer control allowed several things to happen, including 1) tighter process control by better regulation around set-points, 2) on-line quality monitoring and control, 3) relief of operators from redundant tasks, to concentrate on key areas, and 4) elimination or near elimination of dependence upon process-expert operators. The drive for product consistency and quality, supported by computer control, has made processes more efficient, reduced waste, and increased effective production time within the work week.
The variety of process requirements involved has spawned a diverse computer control industry that ranges from billion-dollar companies to small specialty firms. Although there are too many to describe completely, this chapter covers the major equipment suppliers by type, dealing with the subject matter of control without aligning with any one hardware or software manufacturer.
Until the personal computer (PC) emerged as a third platform for industrial control, programmable logic controllers (PLCs) and distributed control systems (DCSs) were the primary computerized controllers for the processing and packaging areas in the breakfast cereal industry. The niche for PLCs in the past was for smaller and stand-alone applications where the process was more discrete and less continuous, with no complex computations. By contrast, DCSs were used in larger or multiple processes that needed to be integrated together. The typical DCS-controlled process tended to be relatively more continuous and less discrete, requiring more computing power, common databases, and archived process data files. However, the PC-based platform overlaps the traditional applications of both PLC and DCS to provide controls for small and mid-size applications.
The distinction between these major platforms is not clear-cut. Larger and more powerful PLCs and smaller, modular, less expensive DCSs have closed the gap between control platforms to allow a user to select from any platform for the medium-size project. Moreover, PC-based platforms can also provide PLC and DCS functionality for small- and medium-size applications.
