Multi-Purpose Systems How Valve Solutions Lower Production Costs in Multi-Purpose Systems
By cleaning multi-purpose systems considerable sums of money may simply be washed away. An example from the cosmetics industry will show how these losses can be in certain cases significantly reduced.
In many manufacturing processes and industry segments, powders and liquids are measured out, mixed and distributed. Water and chemicals, sugar, colourings, flavourings, and perfumes are only a few of the ingredients which are used. Depending on the raw material in question, the costs can vary from a few euro/m³, for example for water and bulk chemicals, to five-figure sums and more per litre for flavourings and perfumes. In large production plants, these materials are fed from storage tanks via piping and valves to the relevant mixers.
Due to the number of product variants, for example in the case of beverages, body care products, cleaning agents and pharmaceuticals, the products are usually produced in batches. This is carried out in multi-purpose systems.
To ensure that the first bottles of men’s shower gel to be produced do not smell of apricot vanilla, all the piping and valves from the storage tanks to the mixers and filling machines have to be thoroughly cleaned each time production is changed over. Each time the equipment is cleaned, product is lost. Depending on the material and the size of the plant considerable sums of money may simply be washed away. Over the course of a year, this may add up to six-figure sums or more. An example from the cosmetics industry will show how these losses can be in certain cases significantly reduced.
Plant Design Determines Cleaning Efficiency
The design of the plant and the cleaning processes are generally the factors that affect the quality and cost of a cleaning process and its duration. The cleanability of a multi-purpose system depends not only on the product being produced but also on the degree of cleanliness required. Incorrect plant design can significantly increase the cost of cleaning and the necessary plant downtime or lead to poor cleaning results.
These are critical aspects, regardless of the industry segment and the product, and will in all cases result in unnecessarily high costs.
The layout and dimensioning of the valves used for distributing the different media is one of the vital features for successful and efficient cleaning. Due to the large volumes which are processed in beverage and milk plants, it has been the practice for many years to work with so-called mixproof valve nodes, mostly in nominal diameters (ND) 40–100 mm. These enable a large number of functions to be combined in a very small space and connect the different components in a space-saving way.
The nominal diameters used in the pharmaceutical industry are usually between 10 and 25. Given these nominal diameters, multi-port diaphragm valve manifolds best meet the demanding criteria of this industry for cleanability and sterilisation.
The function of these valve manifolds resembles in principle that of the valve nodes used in the beverage industry. In the case of the production of cosmetics and body care products, inexpensive ball valves made from stainless steel are very often used.
Automation Using Pneumatic Quarter Turn Actuators
While in the past these were usually operated manually by plant personnel, in today’s plants they are mostly automated using pneumatic quarter turn actuators. In high-performance multi-purpose systems, once the appropriate recipe has been selected in the production control system, the individual ingredients are selected, metered and fed to the mixer fully automatically. The control of the mixer with regard to process parameters such as temperature, pressure and pH value is also completely automated.
The plant engineers at a manufacturer of body care products have been considering for some time now how they could minimise the cleaning losses of perfumes, which in some cases can be quite expensive. This section of the plant was equipped with stainless steel ball valves, which were as usual connected to pipes and fittings to form a highly complex network.
It was deemed preferable to keep using ball valves because of their robustness and low purchase and operating cost. As a first step, the manufacturer’s engineers developed a compact valve node, each with 6–8 ball valves per manifold. This reduced cleaning losses to some extent, but the result was not yet satisfactory. The dead volumes within the solution were still too large.
System Upgrade Paid for Itself in Only Eleven Months
At this point the process automation specialists from Festo came into the picture. They went through the specification of the plant in detail with the customer and then created a complex ball valve distributor manifold for more than 20 perfume storage tanks. With the help of an initial 3D CAD model, this suggestion was discussed with the customer and further optimised.
The distributor was based on stainless steel ball valves VAPB with pneumatic quarter-turn actuators DFPB. Position feedback was via an open position indicator solution using proximity sensors in accordance with the customer’s specifications.
Once the mechanical design work for the highly complex distributor had been completed, a rapid prototyping model on a scale of 1:5 was produced in the Festo Fast Factory. This resolved any lingering doubts about the feasibility of the new solution, and the customer then ordered the first pre-assembled unit.
After the mechanical design work, Festo also assumed responsibility for the automation of the distributor manifold. The remote I/Os of a Festo CPX terminal are used to process the feedback signals from the position sensors. The compact valve terminal MPA supplies the quarter-turn actuators for the ball valves centrally with compressed air.
The integrated fieldbus node provides a connection to the production control system. The compact automation module is installed in a control cabinet directly beside the valve node. The compressed air preparation equipment and the necessary switching logic are also installed in the control cabinet. The compressed air supply lines are bundled and connected to easily accessible multiple connectors, as are the cables for the position feedback sensors.
This makes connection to the plant easier and ensures a neat layout of the cables and tubing. From this point, the lines are routed centrally to the control cabinet. The total costs of the new distributor as well as the upgrade of this application were amortised in approx. eleven months.
Not only this, but the new distributor is considerably smaller and lighter and thus saves valuable space in the production plant. There are fewer connection points between the pipes, fittings and valves, reducing the amount of assembly work required as well as local installation costs. At the same time the risk of leaks is reduced thanks to the smaller number of connection points. This in turn means lower inspection and maintenance costs in comparison with a conventional solution.
Modular Design Ensures a Forward-Looking Concept
When designing the ball valve distributors, Festo’s experienced engineers attached great importance to achieving a forward-looking concept. The modular design can be scaled to cover all kinds of customer applications. In projects of this kind, Festo can offer industry-specific know-how combined with problem-solving expertise acquired over decades in many different industry segments. This means reliability for customers and the benefit of being able to buy good, forward-looking solutions which will increase their productivity.