Shared logic

Improved automation infrastructures and a greater exchange of information between business and technology systems is the way to improve cost efficiency and safety. Colin Carter explains.

The manufacturing constraints used in the production of food, beverages and pharmaceuticals are subject to the same laws and standards, meaning the process control strategies and equipment used for all of them could, in theory, be identical.

The various industries have made good progress in many areas. According to a recent report from the US-based Automation Research Council: ‘Many companies have well-documented food safety programmes that include good manufacturing and pest control practices, good sanitation, Hazard Analysis and Critical Control Point (HACCP) protocols, personnel qualification and awareness training, process validation, change management and an effective product recall system.’

Of course, all of this is difficult to achieve in practice and depends on efficient exchange of information. This has led ARC to call for vastly improved automation infrastructures, even in the most highly-automated facilities, and greater exchange of information between business and technology systems.

In the pharmaceuticals industry, where regulatory compliance is of the utmost importance, Emerson Process Management has just won Frost & Sullivan’s Customer Value Enhancement award for the use of its PlantWeb digital automation architecture — mainly due to the software which can be used by manufacturers as a one-stop shop, integrating everything from record keeping to enabling plant information to be used directly by business systems.

Increased integration has led to improved plant control and profitability at food processor Aarhus Olie of Denmark, where PlantWeb architecture is used with the company’s DeltaV automation system using Foundation fieldbus.

The system integrates everything from Fisher control valves, Rosemount transmitters and MicroMotion Coriolis meters and has to deal with compatibility issues legacy systems that were installed way back in the 1970s.

This compliance with standards, especially with respect to the validation of plant and/or machinery, has also been acknowledged by Siemens. The company’s SIMATIC WinCC Scada system can be supported by software designed to ensure compliance with FDA regulations, and can provide electronic signatures and audit trails where necessary for all information.

The benefits of integrating all plant areas in a single environment have been demonstrated by Siemens at Bradford’s Princes Soft Drinks plant, where features such as a reduced need for manual data entry and less possibility of operator errors have led to tangible cost savings as well as improvements to processes.

But operational improvements and the associated cost savings in the food and pharmaceutical industries are not only possible from large-scale system integration such as those mentioned above. At device level the many advances in technology are leading to improved efficiency and better products.

For example, part of the production process for the UK’s reportedly favourite dish — curry — has been improved at one of the UK’s leading suppliers of ready meals and pour-over sauces by increased automation.

Once again, compliance with clean- liness codes of practice and product quality for the production of some 1,500 tonnes of sauce a week is paramount. A series of Mitsubishi programmable logic controllers (plcs) connect to the same company’s Human Machine Interfaces (HMIs) using a Mitsubishi MELSECNet to a master Q25 plc.

This master manages the overall operation of the plant, including some 500 process control valves, controlling everything from cleaning processes, recipe checking and packaging operations.

And it’s not only hot foods that benefit from increased automation. At Unilever’s huge ice cream plant at Caivano, Italy, Control Techniques’ variable speed drives have been driving down costs at many stages of the production process — from portion control through to final packaging.

The factory produces something like 680 million portions of ice cream a year, with lines for brands such as Magnum and Solero being in the region of 100m long. These lines include sections for mixing, freezing, portioning and shaping and each one relies on around 50 Unidrive SP drives in servo mode with Unimotor servo motors for multi-axis positioning of product along the line.

Variable speed drives — which allow plant components such as pumps and compressors to be run as hard as demand requires rather than switched on or off at full load — can be responsible for a great deal of cost efficiency. They are being used to make savings at Northern Foods’ Riverside Bakery in Nottingham.

Some £30,000 in annual savings are claimed for the installation (by Inverter Drive Systems) of ABB variable speed drives to control the pumping of water around refrigeration units.

Improved accuracy is another claimed benefit of the control system as well as the cost savings from having the pumps running with an average power reduction of 65.2 per cent per pump.

Homogeneity is essential for many pharmaceutical and food/beverage applications, and the degree of ‘mixing’ can be measured in many ways.

One solution developed by AstraZeneca uses near infrared radiation (NIR) analyses to evaluate the homogeneity of materials for tablets and capsule manufacturing. In this system an NIR camera sends images to a National Instruments IMAQ image acquisition board.

Image information is then processed using LabVIEW and NI Vision Builder and Vision software, which extracts information on the blending process from the matrix of data which is used to give a fast analysis of the degree of homogeneity of the batch.

Most of these examples make use of control components suitable for general process control application. There are many examples of products designed specifically for use in food/beverage and pharmaceutical plants.

For example Kontron produces a modular, hygienic HMI with a food-grade stainless steel front panel designed for use in food and beverage applications, while Invensys has recently announced a sanitary vortex flowmeter, 845, aimed specifically at pharmaceutical applications.

ABB also markets its 2600T pressure transmitter range as suitable for ‘harsh environments’ for both pharmaceutical manufacturing and for food and beverage operations.

The food, beverage and pharmaceutical industries have similar drivers — the need to comply with a number of global regulatory frameworks, the need for cleanliness and the need to be competitive and reduce process costs.

In these competitive fields those not keeping up with the latest advances in technology will be swallowed up faster than their products.