Clean and flexible

Regulatory and commercial pressures are the two clear drivers in the market for pumps and valves used in hygienic applications, which has seen major technical development activity by leading manufacturers.

Among the key pieces of European Union food safety legislation is EC 852/2004- Hygiene of Foodstuffs, which covers all stages of production, processing and distribution of food. This requires all articles, fittings and equipment with which food comes into contact to be effectively cleaned and, where necessary, disinfected. They are also to be installed in such a manner as to allow adequate cleaning of the equipment and the surrounding areas.

Also important is EU Law 98/37/EC Machinery section 2.1 Agri-foodstuffs, which requires that machinery be designed and constructed to avoid any risk of infection or contagion. Materials must be non-toxic, have smooth surfaces, reduced projections, edges and recesses, and must be easily cleanable.

Commercial pressures, meanwhile, are pushing food producers to further automate their processes, accommodate decreasing batch sizes and shorten the times that new products are brought to market, notes Ian Dickson, food & packaging manager at Bosch Rexroth.

"Machinery must, therefore, be flexible to allow product modification, reduce the cost of tooling and, at the same time, allow for a high frequency of cleaning and disinfection," according to Dickson.

The drive to improve machine performance and throughput in hygienic requirements has led to interesting innovation covering everything from valve design to the steels used in manufacture to the pneumatics and other supporting systems.

Control valves are traditionally housed in additional cabinets to allow for washdown. However, these devices should be located as close as possible to the devices that they are controlling to optimise the performance of the pneumatic system.

These factors have led Bosch Rexroth to develop its Clean Line valves particularly for the food processing and packaging sectors. These valves, which have protection class rating of IP69K, can be washed down at high pressures (up to 100bar/1450psi) for cleaning and decontamination.

Protective covers help to eliminate the need to house the valve manifolds in a cabinet and enables them to be mounted directly on the machine, adjacent to the process, thus reducing cycle time.

"With pneumatics, the pipelines can act as a soggy capacitor, so if you can get the valves as close as possible to the cylinders you get the best performance." The cabinets, added Dickson, also add cost and often can only be serviced by specialised technicians.

Tyco Flow Control, meanwhile, has added a new high-temperature seat for its Keystone Optiseal butterfly valves, which are used widely in the food & beverage industry. The new Brewseal is designed to extend the operational life of typical units, especially in tough brewing conditions, for example, when processing hot wort.

Features include a one-piece wafer-thin disc stem of the seat that combines high strength with positive disc control while offering minimal disc obstruction to flow. It is rated for 150°C constant service while also offering good abrasion resistance for brewing. The valve body is finished in a special, high gloss siloxane to suit the requirements of the hygienic market.

Another Tyco innovation is a stainless steel non-return valve for reverse flow protection. The Keystone F264J offers ease of maintenance and high flow coefficients in hygienic applications.

The valve features a stainless steel construction and a design that facilitates in-line cleanability. Tyco's design team has also re-engineered the centre bearing area to reduce the rate of wear and tackle the early failure to which non-return valves can typically be prone.

Multi-port valve

Burkert claims its latest multi-port Robolux valves can cut system requirements by half in hygienic processing by reducing the number of valves, diaphragms, pipe fittings and welds required in applications such as filtration and water purification.

According to the company, the multi-port design delivers substantial operating benefits with a patented design that achieves independent process switching functions with one diaphragm.

Operators can therefore replace two traditional shut-off diaphragm valves and at the same time eliminate all dead legs and one T-piece with one single valve. This, claims Burkert, means that sterility is easier to ensure and maintain as well as allowing faster shifts and reduced risk of cross contamination.


Two routes into sanitary pumps market


Leading pumps manufacturers Grundfos and Mono Pumps are following significantly different strategies to gain a firm foothold in the increasingly important market for hygienic process equipment.

Danish major Grundfos aims to become the leading pump supplier to the hygienic and industrial end-user market — a strategy launched with its 2004 acquisition of Philipp Hilge GmbH, a Bodenheim, Germany-based maker of stainless steel centrifugal pumps for the brewery, dairy, food and pharmaceutical industries.

Since the Hilge acquisition, Grundfos has established itself as a full line supplier of pumps and pumping systems to the food, beverage, pharmaceutical and process engineering industries, said Andy Shearer, newly appointed director of sales, IEM at Grundfos.

The Grundfos executive listed the main factors driving the market for sanitary pumps in the UK and Continental Europe as:

1 Importance of hygienic design and cleanability

2 Energy efficiency, life cycle cost reduction

3 Quality and reliability of products

4 Service capability

5 Full line supply

"Our aspiration is for Grundfos to become the leading pump supplier to the hygienic and industrial end user market within the next five years. I believe that with our ever developing product range and competencies this is an achievable goal," said Shearer.

Continuous product development and acquisition are key to Grundfos becoming the leading full line pump provider to industry, continued Shearer. The group invests around £1 million per week (4% of annual turnover) in developing products such as its recently introduced F&B Hygia centrifugal hygienic pump and Novalobe rotary lobe pump.

Grundfos places a high priority on achieving 3A, EHEDG and similar certifications in the food & beverage market, Shearer stating: "Hygienic design and cleanability are critical when dealing with food and beverage manufacture, these standards set minimum criteria for food processing products, materials and their cleanability."

Novalobe, for instance, is designed for applications involving high viscosity liquids, meeting the latest hygiene standards in sterile and aseptic processes. Grundfos has used materials that are EHEDG-approved and therefore meet the requirements of the pharmaceutical, food and the beverage industries.

According to Grundfos, the surface finish of the materials used is of the utmost importance - both for physical properties and to help prevent possible breeding grounds for bacteria and germs. All pumps are designed for delivery pressures of up to 16 bar and a product temperature of 150°C.

Mono Pumps is, likewise, making a major push into the hygienic market with its new range of progressing cavity (PC) pumps, called Helios. With 29 models, the Helios range can handle flow rates up to 180m3/h and pressures up to 24 bar.

The Manchester-based company has supplied its PC pumps to the food sector in the past, but Helios is its "first full-on attempt to give the food industry what it needs" officials said at a recent launch.

Mono is pitching Helios as an alternative to lobe pumps. The company claims its product offers better seal and wear characteristics due to a special interference fit between the rotor and a resilient rubber stator, and gentler handling of shear sensitive products at high flow rates.

Helios pumps feature a double-helix resilient rubber —usually nitrile — stator and single-helix metallic rotor. The design, claims Mono, meets a range of food industry requirements including hygienic design and construction, CIP and the ability to handle viscous products and maintain consistency and integrity of shear sensitive products during processing.

While Helios pumps do not carry certifications such as 3A, orders from the UK and Europe are running ahead of planned levels, said Ian Davies, the company's export sales manager. Early applications have been for fruit juices, concentrates and dairy products as well as in the chocolate handling sector.

Mono previously held certification for its hygienic range of pumps, but over a period of some 15 years only supplied around three pumps where 3A certification was required.

"Consequently," said Davies, "with the Helios range we decided to concentrate on supplying a pump that was 'fit for purpose', meeting customer requirements regarding flow rates, pressures and cleanability.

"Since the launch of Helios, we have had no enquires for certification. However, should this be required in the future, we are prepared to review this stance and gain the relevant certification to meet customer needs at that time. "