Which design details prevent dead spaces and make CIP/WIP cleaning easier?
For a hygienically appropriate design of plants and piping systems, the decisive features are those that avoid product residues, stagnant media and areas that are difficult to clean, while at the same time enabling validatable cleaning.
Essential design principles
Dead-space-free pipework
Branches, T-pieces and stub lines should be executed as short as possible. Dead spaces, blind ends and unnecessary branches are to be avoided so that cleaning media can reach the product-contact areas reliably.
Self-drainability
Lines, apparatus and surfaces should be executed with a defined gradient so that cleaning and rinsing media can drain completely and no residual pools arise.
Rounded geometries
Internal edges, transitions and vessel corners should be designed with sufficiently large radii. Sharp angles and abrupt transitions create flow shadows and areas of deposition.
Smooth surfaces
Product-contact surfaces require a high surface quality. Smooth, passivated or electropolished surfaces improve cleanability and reduce build-up.
High-quality weld seams
Welded joints must be cleanly executed, low in pores and fully penetrated. Smooth and controlled seams prevent additional niches and facilitate cleaning.
Hygienic seals and connections
Seals should be embedded flush and without crevices. Threads should as far as possible not be exposed in the product-contact area.
Fittings with minimal dead space
Valves and shut-off devices must be installed and designed so that they can be rinsed and drained completely. Geometries that are difficult to rinse and unnecessary cavities are to be avoided.
Flush-mounted attachments
Connections, sensors, measuring points and instruments should be designed as flush or front-face versions, without projections, gaps or recesses.
Suitable vessel geometry
Conical or inclined bottoms with the lowest point at the outlet facilitate complete discharge. Internal contours should be round and free of dead zones.
Spray technology suitable for CIP/WIP
Spray balls, rotating nozzles or lance systems must be arranged so that all surfaces are wetted sufficiently and no spray shadows remain.
Sufficient flow and process management
The design must aim at sufficiently high flow velocities and turbulent conditions so that the mechanical cleaning effect is maintained.
Suitability for validatable cleaning
The design must allow reproducible cleaning under defined parameters such as time, temperature, chemistry and flow.
The difference between CIP and WIP
CIP is designed for fully automatic, validatable cleaning without dismantling and places particularly high demands on freedom from dead space, drainability and flow management.
WIP frequently serves for wetting, dust binding or pre-cleaning and may require additional spraying or rinsing equipment in order to reach areas that are difficult to access as well.
In brief
Dead spaces are avoided through short, drainable, smooth and easily accessible geometries. Good CIP/WIP cleaning arises from the interplay of hygienic design, suitable spray technology, sound drainability and reproducible process management.
How amixon® implements dead-space-free construction and hygienic design
These design details are used throughout the amixon® manufacturing programme, that is in all mixer and process solutions for hygienic, pharmaceutical and industrial applications. These include VM, HM and AM as well as SH, KS and the Gyraton® silo mixer.
Freedom from dead space as a design principle
In the amixon® precision mixers named, the mixing chamber and mixing tool are welded free of crevices and ground smooth. In the product-contact area there are no gaps, screwed joints or capillary crevices. The mixing tool is supported and driven exclusively from above, so that the lower shaft passage, classically critical for contamination, is eliminated entirely.
The standard connection with a discharge flap closes flush and free of dead space with the inner wall of the mixing chamber. Dead-space-free ball segment fittings are available as an alternative. The large inspection doors are manufactured by the Clever-Cut® process and seal permanently free of dead space with the OmgaSeal® door seal. On request, a vacuum-tight or overpressure-tight seal is also possible.
Cleaning: wet and dry, validatable
Integrated washing lances and freely programmable target-jet cleaning nozzles allow defined and reproducible CIP and WIP cycles. This reduces the cleaning effort and markedly lowers the consumption of wash water. The SinConvex® mixing tool supports the complete drainage of product and cleaning medium. The mixers are designed for dry and wet cleaning regimes, so that switching between dry and wet cleaning is provided for by design.
The Clever-Cut® doors provide complete, ergonomic access to all product-contact surfaces. They are sealed with the OmgaSeal® system and are regarded as dead-space-free. This forms the basis for visual cleaning inspection and for sampling by swab or rinse.
Certified standards
On request, amixon® mixers meet the EHEDG guidelines, the FDA hygiene guidelines, the design rules of the 3-A Sanitary Standards and GMP requirements. The VM and HM models can be used in FDA-compliant form as sterile mixers and reactors. With free-flowing materials, ComDisc® residual discharge can reach 99.997 % and better and minimises residues as well as cross-contamination risks during formulation changes.
Manufacture in Paderborn as the quality foundation
amixon® develops and manufactures exclusively at the Paderborn works with the greatest depth of manufacture and uses components from Germany exclusively. As a certified welding company with European, Japanese, Korean and American qualifications, amixon® designs every apparatus as a one-off on the basis of the operator's URS. Quality control remains entirely in-house without gaps, and every specification is verifiable down to component level. This manufacturing autonomy also secures long-term supply: every component can still be re-manufactured reproducibly decades later.
Qualifiable and documented
For regulated environments, amixon® supplies the plant ready for qualification. Every apparatus is a one-off manufactured to the URS in-house with quality control without gaps. amixon® assists on request with DQ, IQ and OQ. Documentation and execution follow, on request, EU GMP and FDA 21 CFR Part 11.
On request the mixers meet the relevant standards EHEDG, the FDA hygiene guidelines, the 3-A Sanitary Standards, USDA, GMP, ATEX and ASME. They are integrated into the operator's validation concept from the URS through to commissioning.
Verification in the amixon® pilot plant
Whether the specific formulation delivers the expected results is verified by amixon® in advance at the pilot plant with 35 test units under real conditions. The trials are carried out, evaluated and documented jointly and form a robust basis for decision-making before the investment.