Control System

Control systems for operating CIP must try to perform CIP operations in a precise sequence. In the early CIP control systems, pumps and valves were controlled manually and time was kept using a stopwatch. Overdependence on the human element prevented the precise sequencing in early control systems (4,9). As the CIP control system evolved with time, the use of electromechanical relays became common. The relays were used to perform the automatic sequencing, but the system had an inherent ability to fail at the wrong time (9). The present-day CIP control systems are microprocessor-based. The development of inexpensive and reliable microprocessors has accelerated the use of microprocessor-based control systems in CIP. Control systems for CIP have improved a great deal in the past 40 years from the unreliable to a very reliable and flexible microprocessor-based controls where cycle time, chemical concentration, and temperature are fully adjustable to suit individual cleaning needs (10).

The center of any microprocessor-based control system is a process controller containing a central processing unit (CPU), memory, and an input/output (I/O) interface. Input—output devices provide the operator access to the control system. The CPU accesses the operator-oriented equipment (such as pushbuttons, pilot lights, rotary switches, thumbwheel switches, LED readouts, CRT screens, and printers) and process-oriented equipment (such as pump motors, valve solenoids, pressure sensors, level probes, flow meters, and temperature switches) through the I/O devices. An operating logic, which may originate as a verbal description or an algorithm, describes the interaction and coordination among the operator-oriented equipment, the process-oriented equipment, and the control system. The operating logic or computer program can be prepared from the algorithm. The CPU executes the operating logic or the program. Because the controller's actions are determined by the computer program, any configuration of equipment and/or program sequence can be implemented and controlled by such a control system. The application of microprocessor-based control systems has helped in making the modern food-processing plants and associated CIP systems completely automatic (7,9,10). With precisely controlled operations, a more sophisticated CIP unit design has become possible, resulting in increased savings on energy, water, and cleaning chemicals (10). The microprocessor-based control systems have provided new opportunities for modifying and improving CIP operations and concepts.

Even very reliable modern control systems can malfunction; therefore, regular routine checks and maintenance are necessary (1,4).

Homemade Pet Food Secrets

Homemade Pet Food Secrets

It is a well known fact that homemade food is always a healthier option for pets when compared to the market packed food. The increasing hazards to the health of the pets have made pet owners stick to containment of commercial pet food. The basic fundamentals of health for human beings are applicable for pets also.

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