Mixproof valve technology is involved in almost all hygienic dairy processes, from milk reception and heat treatment to product storage. An almost infinite variety of adaptable hygienic valve types ensures the essential safety of the product as well as the required sustainability of the process from the raw milk to the finished product.
Mixproof valve technology for a sensitive product
More than five decades ago, Otto Tuchenhagen, already a renowned dairy technology developer, began pioneering reliable valve concepts that quickly became indispensable in the dairy industry. At his facility in Buechen near Hamburg – now GEA’s competence center for hygienic valve technology – he invented the mixproof double seat valve in 1967, which laid the foundation for today's acclaimed GEA VARIVENT® family of process valves.
The GEA VARIVENT® valve range offers almost unlimited functional options that are well suited for dairy applications, reflecting GEA’s mission to provide optimized engineering solutions for safe, sustainable and economical processing.
The flow paths and valve chambers of GEA’s hygienic valves are designed without dead spaces. A flexible sealing concept ensures the exact fit of the material, such as EPDM, FKM, HNBR or PTFE, to the respective process temperature, viscosity and flow rate at each point of application.
Mixproof double seat valve technology, as pioneered by GEA, is at the center of safe process solutions. When processing milk, contact between the product medium and other media must be ruled out. The double seat valve ensures this and thus enables the installation of switchable flow paths for two incompatible media, such as product and cleaning fluid, without risk of contamination – the two valve seats keep the media separate from each other even in the event of a leak.
GEA engineers are constantly adding innovations and special functions to the hygienic valve technology portfolio, many of which have become established in the dairy industry and beyond.
Optimization potential through automation
Valves in milk processing systems are usually equipped with monitored control tops. Modern concepts are increasingly relying on digital device networks instead of purely pneumatic systems in order to optimize the efficiency of automated operations and ensure economic benefits that are likely to become indispensable in the future.
The current T.VIS® control tops on GEA process valves are a key to these benefits. Adjustable measurement and transmission functions ensure error-free automatic control and monitoring of all valve operations according to the centrally programmed specifications. The selectable LEFF® function in T.VIS® A-15 control tops from GEA can achieve a more sustainable process by saving up to 90 percent on cleaning media through optimized timing of the switching movement.
The valves can be commissioned automatically in seconds, even without trained staff. Consistent automation also simplifies the entire system setup for processes that can be fully validated. Using a modern IO-Link system can enable early, efficient integration into effort-optimized Industry 4.0 environments.
Milk reception, distribution and storage
From the delivery of the raw milk, controlling and monitoring the product flow is one of the most important tasks of hygienic valve technology in the dairy process.
Divert valves allow the merging of the product flows from two pipes or the distribution of product to two pipes. GEA offers different types of divert valves that are designed for the respective flow direction.
Sampling valves enable the control of incoming raw milk. GEA VARINLINE® process connections are available for adding further measurement devices and other functional components to pipelines.
Efficiently controlled heat treatment
Control valves are used for heat treatment processes, which are of crucial importance for safe milk processing. These valves serve as actuators in control loops and are used for pressure regulation, flow control, for the mixing of liquids and especially for the temperature control in heat exchangers. Such valve types tailored to specific functions are listed in the catalog GEA VARIVENT® Hygienic Special Application Valves.
Safely hygienic CIP cleaning
All product-carrying pipes and flow paths, especially in dairy operations, must be cleaned of residues at regular intervals, as the nutrient-rich milk is particularly susceptible to germs. Permanently installed cleaning loops avoid the need to interrupt the process for this and save valuable time.
The valve blocks that act as switching points are typically equipped with double seat valves so that the milk cannot come into contact with the cleaning agent. Single-seat valves or GEA butterfly valves may be used for the less critical feed of cleaning media. For strong acids or bases, VESTA® valves from the GEA range of aseptic valve technology are a recommended choice.
Resource-saving product recovery solution
The further a product batch goes through the process, the greater its value, and the more important it becomes to recover product residues from pipes before they are flushed out in the pipe cleaning cycle.
Pigging of the product-carrying pipe minimizes product loss during pipe cleaning and also supports water savings in the initial flushing stage of the cleaning process. A GEA VARICOVER® pigging system recovers the valuable product by sending a pig through the pipe, propelled through the given pipe section by air, another gas or water, and then back to its waiting position before the flushing of the pipe. This is particularly important with sticky products, such as yogurt, that tend to build up more residue.
The pigging process ensures the same yield from less raw milk and less flushing water. In this way, dairy companies can make their process even more efficient and use natural resources responsibly.
Innovations for special safety requirements
When selecting valves for their dairy processes, U.S. plant operators as well as international companies striving for globally standardized processes must take into account the specific PMO guidelines that apply in the U.S. GEA engineers were the first to develop PMO-approved double seat valves that offer the demanded additional protection against possible leakage. Special balancers on both valve disks protect the valve from pressure shocks, and a built-in vacuum effect further prevents contamination by incompatible media. This innovation has made it possible to implement efficient, switchable and cleaning loops with PMO approval and avoid costly downtime.
Further dairy process solutions from GEA
To cover other processing stages in dairy production, GEA offers numerous special components and integrated solutions. For process requirements according to higher hygienic classes, such as the aseptic filling of ambient-temperature milk products, special series such as GEA D-tec® (UltraClean) or GEA Aseptomag® (Aseptic) are available.
To support applications in which an exactly constant temperature is important, GEA has developed jacketed VARIVENT® valve housings that have become standard in chocolate and ice cream production.
GEA also offers customer-specific integrated solutions that incorporate hygienic valve technology for numerous applications – from mixing and degassing stations and systems for cross-flow membrane filtration to GEA BATCH FORMULA® high-shear mixers. Technical consultants from GEA and GEA test centers for carrying out process tests provide support for system planners.
Further central components for dairy processes are additionally available in the GEA Group portfolio – from pumps and tank cleaners to milk separators, homogenizers and dryers.
Economical, effort-reduced maintenance
Last but not least, spare parts logistics is an important aspect when using hygienic valve technology. Consistently standardized construction modules in the GEA valve range with a small number of parts reduce the operating costs for maintenance and spare parts storage. If necessary, the global GEA service network is available with quick help.
From the days of Otto Tuchenhagen to the next era of dairy technology innovations, plant operators who work with GEA Hygienic Valve Technology can be certain to stay ahead of the curve when it comes to safe milk products and a sustainable, efficient process.