For sterile and high-purity production, residual product, dead zones and validation overhead all erode yield and uptime. The Alfa Laval LeviMag UltraPure aseptic magnetic mixer addresses each of these pressure points with a levitating-impeller design, hygienic surface finishes and a documentation package built around validation. The result is a mixer that protects high-value batches, simplifies cleaning and shortens qualification.

How the levitating impeller mixer eliminates dead zones and axial wear

An impeller with radial blades inside the tank rotates under torque from an Alfa Laval magnetic coupling. The coupling is designed so the impeller levitates at all times, which enables true dry-running and complete drainability of the process fluid. CIP liquid and steam flow freely around every part of the mixer for thorough cleaning, while levitation removes axial wear at the bearing interface. This combination is what delivers efficient mixing down to the last drop and reduces contamination risk from wear particles.

Hygienic design for pharmaceutical tank mixer duties

All product-wetted surfaces are finished to Ra <0.38 µm, mechanically polished and electropolished per ASME BPE SF4. The impeller and weld plate are supplied in EN 1.4435 (316L/UNS31603) as standard, with EN 1.4529 or EN 2.4602 available on request for more demanding chemistries. The SiC (Silicium Carbide) female bearing per EN 12756 pairs with seals available in EPDM, FPM or FFKM to suit elastomer compatibility requirements. The drive rotor, shaft and console/flange are AISI304 (UNS S30400).

Operating envelope and process flexibility

The LeviMag UltraPure operates from -1 to 7 bar(g) and accepts mixing media up to 90 °C. SIP cycles are supported to 125 °C at up to 50 rpm and 150 °C at 0 rpm, while CIP runs up to 95 °C at up to 50 rpm. Five impeller diameters — 100, 150, 200, 250 and 300 mm — cover speeds from 10 rpm up to 800 rpm, with maximum speed depending on impeller size. Two weld plate sizes are available: WP50 with a clamp connection for 100 and 150 mm impellers, and WP81 with a flange-bolt connection for 200, 250 and 300 mm impellers. Consoles are offered in standard or extended height to suit insulated tanks, with a mounting angle from 0° to 45° to horizontal (the motor must not point downwards).

Validation support with Alfa Laval Q-doc

Every LeviMag UltraPure ships with the Alfa Laval Q-doc documentation package, which provides full transparency of the supply chain and supports the validation process. The mixer complies with Regulation (EC) No. 1935/2004 and EC GMP, with USP Class VI <88> for relevant elastomers, FDA CFR 21 for non-metallic parts, 3.1 material certificates per EN10204 for all wetted parts, a TSE/ADI declaration and USDA H1 food-compatible gearbox oil. An ATEX version is available against directive 2014/34/EU with marking II -/2G Ex h IIC T4 -/Gb.

Cleanability, drainability and uptime

The open geometry and levitating impeller deliver optimized CIP through full drainability, with no axial wear surfaces to harbour residues. Maintenance is straightforward thanks to a detachable drive unit and a simple build-up of impeller, seals, bearings, weld plate and connections. For real-time process visibility, an optional Alfa Laval Magnetic-Inductive Speed Sensor is available on impellers prepared for it.

Sizing is supported by the Alfa Laval configurator and published selection charts based on media viscosity, tank volume, tank diameter, bottom shape and the chosen duty level. The selection charts assume a specific gravity ≤1.1 and a liquid height ≤2.5× the tank diameter; outside these preconditions, Alfa Laval Global Technical Support should be consulted. Euroflow's specialists work alongside engineering teams to translate process data into the right impeller size, weld plate, motor option and accessory package.