PuK - Process Technology & Components 2022

Components Innovative double-seat valve Next level safety: How products and processes get safer with innovative valve technology Hygienic planning of the product flow and the cleaning process in the food, beverage and dairy industries is getting more and more complex for plant operators. As quality demands and production loads increase, process technology requirements are intensifying. The new mixproof double-seat valve from GEA is a good example of how manufacturers can get more peace of mind and more control by protecting their sensitive products and processes even when something goes wrong. To meet these challenges, the supplier has designed the double-seat valve with a cavity chamber featuring a vacuum self-drainage as well as balancers on both valve discs. The design protects products from contamination and mixing even under excessive loads and when other safeguards fail. “Safe hygienic production protects consumers and prevents expensive opposite pipeline while a valve seat is lifted or during cleaning, even if one seal is defective. “We’ve got physics on our side – and we don't need any extra components for this,” explains the senior product manager. Put simply, the Venturi effect occurs when the static pressure of a liquid is reduced at the narrowest point of a cross-section. When Hygienic reliability is pivotal for the future viability of production facilities in the dairy, food, beverage and pharmaceutical industries: Product integrity and increasingly stringent hygiene requirements are the strongest innovation drivers. With the new double-seat valve, GEA is giving process valve users the technical means to meet the strictest safety standards for tomorrow’s requirements. Fig. 2: The leakage chamber’s physically optimized design creates a negative pressure that directs escaping product to the periphery immediately and without risk of contamination if a seal fails (Venturi effect). Fig. 1: With its innovative technology, the new double-seat valve transcends established product safety requirements. (Photos © : GEA) product recalls and the ensuing losses,” says an expert in hygienic valve technology. “Founder Tuchenhagen’s invention of the double-seat valve was already a step towards maximizing product safety, even at that time. Now we’re deploying our new technology to meet the challenges facing manufacturing companies in the future.” Preventing mixing when seals fail Double-seat valves are inherently mixproof. The special design features of the valve generate the Venturi effect when the valve seat is lifted, creating a vacuum at the opposite seal. This prevents pressure build-up at both sealing areas on lifting. As a result, no cleaning fluid can enter the a product flows through a smoothwalled pipe, the flow velocity increases at the narrowed cross-sectional area, while the local pressure at this point drops. The Venturi effect is named after the 18 th century Italian physicist Giovanni Battista Venturi. His discovery is based on Bernoulli's principle, which describes the conservation of mechanical energy in inviscid fluid dynamics: The velocity of an incompressible fluid passing through a constriction must increase according to the principle of mass continuity, while its static pressure must decrease. If a fluid gains kinetic energy due to its increased velocity when it passes through a constriction, this will be compensated by a decrease in pressure. 102 PROCESS TECHNOLOGY & COMPONENTS 2022

Components Innovative double-seat valve Double balancers to counteract overpressure With new units being built and set up under increasing time pressure, the risk of pressure surges and other overpressure situations during operation is on the rise. “We have to make sure that if there are pressure surges, the valve discs don’t move unexpectedly and generate an error message,” explains the expert in hygienic valve technology. To solve this problem, the supplier has equipped the valve discs in both pipelines with balancers that counteract the product pressure. The lower balancer neutralizes the forces acting in the opening direction. The closed valve can withstand pressure surges of up to 50 bar. Fig. 4: Up to four feedback signals provide the operator with the assurance that the valve’s operating status is accurately documented at all times. tenance-free. This means that service intervals are longer and processes are interrupted less frequently. Process control with a valve unit To ensure maximum control, the hygiene concept includes the entire valve unit, including the control head. Using control heads, the supplier integrates the double-seat valves into the automation design features of the units. This lets the operators monitor the exact switching position as well as the positions of the valve at any time and provides full transparency of the valve functions, which in turn makes processes more reliable. So far, not all industries are using this valve unit with a valve and control head. The digital monitoring and control functions in particular are a basic prerequisite for Industry 4.0-capable production lines. The supplier wants to encourage manufacturers to take this step because control heads have immense potential for predictive maintenance and process sustainability. Digital control heads would also help plant operators boost the traceability and verifiability of the hygienic process chain. Safe worldwide Fig. 3: The valve is fitted with specially shaped balancers in both pipes, so it remains stable in the closed position even when subjected to water hammers. It even stays fully functional if the medium expands thermally. Thanks to the design features of the mixproof valve type, the company has already been able to pass the Customized BASIC and PLUS variants The new valve is available in two versions: a PLUS option with all the latest features in one complete package and a more economical BASIC variant with a smaller range of functions, without a balancer cleaning device. This feature ensures that the lower balancer is completely flooded from the outside when the seat lifts during CIP cleaning. All surfaces in contact with the product can be cleaned without any additional components, and the product is also protected from contamination. In keeping with the standard valve product range, the actuator unit of the valves is designed to be main- Fig. 5: The hygienic design of all components ensures maximum valve cleaning efficiency, with automatic cleaning of the outer balancer when the valve disc is lifted off the seat. PROCESS TECHNOLOGY & COMPONENTS 2022 103