Sweet solutions

Improving control systems can have a positive impact on company costs as well as conserving raw materials, making better use of resources and reducing the need for waste disposal. Julia Pierce reports

There is little doubt that refining and improving process control can have a positive impact on a company’s costs.

In the pharmaceutical and life sciences markets, for example, increasing automation of testing processes is allowing laboratories to remove the need for some controls over the laboratory environment, with associated cost savings.

Raytek recently started to sell the Fuji QuickGene range, which is used in genetic testing and studies. The devices isolate high-quality DNA and RNA from samples automatically, reducing the risk of contamination and removing the need for isolation conditions.

‘This area is very well served by manual systems,’ said company director Antony Dewar. ‘However, the products have moved on from a situation where people are carrying out manual processes with a small number of samples. The use of robotics at this level is used in Japan but so far hasn’t spread further afield.’

Elsewhere, in the food and drink sectors, improving systems is having an important impact on a firm’s energy and resource use. Envirowise, the government-funded body that offers UK businesses free, independent, confidential advice and support on practical ways to increase profits, minimise waste and reduce environmental impact, has highlighted the importance of good process control systems in this area.

It says effective process selection, design and control can reduce costs by conserving raw materials, making better use of resources and reducing the need for waste disposal.

According to the agency, good process control begins at the earliest stages of product design and selection of manufacturing processes, with process designers ensuring that full advantage is taken of the powers of automation at a high level of decision-making. To do this, they must determine exactly what extent of process control will be best and to what extent it will interact with overall business monitoring systems.

Most importantly, companies must have the confidence to change the configuration of their processes. Examples of how they can do this include eliminating the need for storage of intermediate products, and increasing automation of plant cleaning such as pigging of lines or clean-in-place (CIP) technology, which may generate less waste than more traditional processing methods.

Eurotherm has produced solutions that can save time during the manufacture of substances such as chocolate. Tumbling the various ingredients generates considerable heat, which can cause incomplete mixing. Because there is a large amount of chocolate in relation to the surface area of the conching part of the process, it takes a long time for the chocolate to heat up or cool down. The company uses a cascade control set up with heating and cooling controlled by pulsing solenoids that allow hot and cold water to flow into into the conche’s jacket.

A cascade photovolataic feed forward option means it is possible to limit the temperature difference between the water jacket and the chocolate, ensuring product quality is consistent without over-cooling the contents.

In brewing, during the barley malting process different controllers are often used for the germination and kilning processes. With careful design, Eurotherm says a single unit can be used for both applications, therefore minimising the number of installed units, as well as reducing cubicle sizes and costs. Existing installations have shown that the kilning process time can be greatly reduced providing significant energy savings.

Katronic also specialises in creating equipment that can help to reduce the environmental impact of manufacturing processes. The company designs and produces both fixed and portable ultrasonic flow meters for both the food and drink and pharmaceutical industries. The company’s focus is on clamp-on ultrasonic meters and non-invasive process measurement instrumentation using advanced electronics and sensor technologies. As a result, Katronic offers both portable and fixed devices.

‘There is much interest in energy efficiency,’ said sales manager Andrew Sutton. ‘A lot of plants were built when water was just seen as a consumable, and very little thought was given to the cost implications of using it. However, that has now changed and water consumption is proving very expensive. By the time water has been sourced and heated, with the energy used for this being paid for, then reprocessed and put back into circulation, it probably costs more per litre than petrol.’

Rising energy bills have not helped the situation, and may have quadrupled in the past decade. ‘Legislation is encouraging more people to be more aware of their energy use through instruments such as carbon trading and the climate change levy,’ said Sutton. ‘However, it is not just there to punish — it can also be used to promote good practice, so people are now trying to use it to their own advantage.’

Katronic’s equipment can be used for metering who is using water as well as monitoring the processing of effluent. Energy consumption of, for example, the plant’s air conditioning system can be examined to determine where changes might be made to lower running costs. As the equipment is non-invasive, it does not require pipeline modification.

In both food and drink and pharmaceuticals this is vital to ensure there is no contamination of the contents. It also means the equipment can be installed without shutting down the plant — something that is particularly important in the food and drink sector, where sheer volume of orders means many plants must work constantly. As stopping and starting processes usually adds to inefficiency, it is also more environmentally friendly.

‘Many factories were built without the installation of metering systems — they were not designed to measure efficiency as this was seen as an unnecessary expense,’ said Sutton. ‘With many systems it is possible to determine temperature and pressure but not flow. This means it is hard to discover where a problem exists, if there is one. For example, water that is too cold could just as likely come from flow that is too fast as a faulty boiler.’

One positive advantage to improving environmental performance is the increasing marketability of green credentials and their high value among consumers.

With government, consumers and rising energy prices putting pressure on both large and small companies to trim their use of raw materials, using the latest process control systems to fine-tune production is vital. It is worth remembering, then, that there are secondary benefits to improving process control, both to a firm’s bottom line and the environment as a whole.