Control System in Food Industry

1. Introduction:

A control system manages, commands directs, or regulates the behavior of other devices or systems using control loops. It can range from a single home heating controller using a thermostat controlling a domestic boiler to large industrial control systems which are used for controlling processes or machines.

It is one fully integrated system that provides the synchronization of all applications and devices involved in the manufacturing process. This allows for the successful merging of information flow from the distributed control system (DCS) and supervisory control and data acquisition (SCADA) systems so that it is available in one interface in real-time. And one of the best means of unifying these communications is by using a single industrial software system.

In the food industry control system is a means of computerizing best practices within a food & beverage factory, restaurant, or catering operations. It gives managers a better idea of the flow of food processing as food processors are becoming increasingly aware of the power of data-driven insights to optimize their use of raw materials, enhance food quality and safety, and guarantee traceability and support for continuous improvement.

It also helps industry owners to introduce the same financial rigor to dining establishments or catering companies that make manufacturing operations more effective. At the sharp end, it provides the food industry with a more structured way of planning operation, considering nutritional and financial considerations.

2. Objective:

The main objective to implement control system in the food industry is to improve the economics of the process by achieving the following objectives:

• Reduce variation in the product quality, achieve more consistent production and maximize yield,
• Ensure process and product safety,
• Reduce manpower and enhance operator productivity,
• Reduce waste and
• Optimize energy efficiency

The Control system becomes essential nowadays as both consumers and regulatory bodies demand complete transparency and the highest food quality. They want to understand every step of a product’s journey: where all its ingredients came from, how it was made, its nutritional value, and if it was ethically sourced. Therefore, it’s essential to have a digital control system that records & provides feedback on every step of a product’s journey.

3. Types Of Control Systems:

There are two common classes of control action: manual control (open loop) and automatic control (closed-loop).

3.1. Manual control: This type of operation depends on the skill of individual operators in knowing when and how much adjustment to make. Therefore, manual control may be used in those applications where changes in the manipulated parameter cause the process to change slowly and by a small amount. This is possible in plants where there are few processing steps with infrequent process upsets and the operator has sufficient time to correct before the process parameter overshoots acceptable tolerance. Otherwise, this approach can prove to be very costly in terms of labor, product inconsistencies, and product loss.

3.2. Automatic Control: In automatic control, the process parameters measured by various sensors and instrumentation may be controlled by using control loops. A typical control loop consists of three basic component

• Sensor: the sensor senses or measures process parameters and generate a feedback output acceptable to the controller.
• Controller: the controller compares the measurement signal with the set value and produces a control signal to counteract any difference between the two signals.
• System: Finally, the system receives the control signal produced by the controller and adjusts or alters the process by bringing the measured process property to return to the set point.
  

It is best to consider the controllability of a process at the early stage, rather than attempt to design a control system after the process plant has been developed to minimize the loss of resources.

It is well known that the food production processes are strongly non-linear, time-invariant, and often unstable. Automation of food production must handle these properties properly and employ them actively. It is a necessary step for generating the desired food structures, for inactivating and avoiding harmful chemical reactions which can lead to a substantial decrease in food quality.

The provision of the world population with food represents one of the most important future challenges for science and technology. In this context, many different objectives arise. In many countries of the world, the most urgent task is to satisfy the original nutritive minimum requirements. On the other hand, food has further functions in industrialized nations as the settlement of a special enjoyment or the promotion of health.

Any discussion regarding the automation of food production must distinguish the original production and the further treatment from the goal of preparing food for consumption, preservation, or refinement. For example, the original production of fish and sea animals take place predominantly in the oceans, those of fruit and vegetable in agricultural production centers. The automation in food production farms or centers differs fundamentally from such automation in factories. Nowadays to reach a larger market we need to ensure the safety and freshness of these items but with the manual process it takes a long time to sort and arrange the product and deliver them in time but with the help of control system or automated system these tasks complete with utmost efficiency & transparency.

4. Importance of control systems in the food industry:

• To maximize the benefit and for proper execution, we need digital control systems which save the organizations from costly failures in manufacturing.
• As the demand increases day by day, food manufacturers have increasingly adopted computer-based systems for process control. This is primarily due to data accessibility y, application flexibility, and low cost provided by microprocessor technology to ensure adequate reliability.
• Control system validation also ensures the proper operation of equipment under normal and abnormal conditions. Validation helps to assure product safety as well as the safety of manpower working in the factory.

5. Guidelines and standards:

To ensure the correct action some guidelines & standards should be followed for the computer-controlled systems:

The FDA Perspective: DA defines validation as “the establishment of documented evidence, which provides a high degree of assurance that a specific process will consistently produce a product meeting its predetermined specifications and quality attributes” (FDA, 1987a). FDA promotes the concept of control system validation as a part of process validation within the food industry and has established some inspectional guidelines. which states that all food needs to be produced in such a way as to make sure that it has not been “prepared, packed, or held under insanitary conditions whereby it may have become contaminated with filth, or whereby it may have been rendered injurious to health.”

6. Technology used:

Nowadays “big data” approach to the whole food supply chain (from farm to fork), would improve production efficiency and security and enable a new level of traceability in short, one of the most important lessons of the industrial revolution – the digital one – is that data is not a by-product, it is real added value and should be considered as the automation unique selling point. To cope with the extremely complex and variable scenario, a significant step-change in reducing food processing costs while increasing food quality and security is urgently needed. In this context, systematic use of automated & control systems with fully integrated digitized process control would facilitate a major advancement in food manufacturing efficiency, delivering significantly reduced production costs whilst lowering energy requirements and food waste.

7. Reference:

• “Feedback and control systems” – JJ Di Steffano, AR Stubberud, IJ Williams. Schaums outline series, McGraw-Hill 1967
• https://circuitglobe.com/difference-between-open-loop-and-closed-loop-system.html
• Process Control in Food Processing Article by Keshavan Niranjan, Araya Ahromrit and Ahok S. Khare
• Food Technology Article by SASHA V. ILYUKHIN, TIMOTHY A. HALEY, JOHN W. LARKIN Stanbury, P. F., Whitaker, A., Hall, S. J. 1995, Principles of Fermentation Technology
• food manufacture 4.0 – automation and robotics at the service of food manufacturing article written by Andrea Paoli, Head of Food Manufacturing, Robotics and Automation at the National Centre for Food Manufacturing, University of Lincoln
• https://www.dataforth.com/introduction-to-pid-control.aspx
• https://blog.bitsathy.ac.in/importance-of-instrumentation-engineer