Selecting a hygienic top-mounted agitator means matching tank geometry, product rheology, hygienic class, and duty profile in a single specification. The Alfa Laval ALT addresses this by separating the unit into five configurable elements — drive, seal arrangement, shaft, EnSaFoil foils, and options — so each parameter can be tuned to the application rather than compromised to fit a fixed model.

How the EnSaFoil impeller agitator delivers high flow at low shear

The EnSaFoil impellers are available with two or three blades in diameters from Ø125 mm to Ø1900 mm. Their profile creates a strong axial pumping effect, generating the volumetric flow needed to keep tank contents homogeneous while limiting shear on sensitive products such as yoghurt mixes, cream, and protein solutions. The result is consistent blending across duties ranging from simple homogenization to dispersing powders, suspending particles, and supporting heat transmission in jacketed tanks.

Modular configuration: drives, seals, shaft, and foils

The drive can be specified as direct motor, coaxial gearbox, right-angle or worm gearbox for low-headroom installations, or parallel shaft gearbox, with or without a stainless steel bearing frame. Seal arrangements cover atmospheric tanks through to aseptic high-pressure duties, the shaft is dimensioned to tank height, and the EnSaFoil foils are selected by blade count, diameter, and surface finish. This breadth lets a single product family cover storage, mix, crystallization, and flocculation applications without bespoke engineering.

Hygienic design for CIP and aseptic duties

The ALT eliminates the typical hygiene weak spots of agitator design. There is no flange coupling inside the tank — the shaft uses a special internal connection — and the bearing frame sits outside the wetted zone with O-rings for external wash-down. The foils have no shadow sides between blades, no plane surfaces, and no grooves, supporting reliable drip-off and CIP cleaning. Surface finish options range from industrial shot-peened Ra < 3.2 μm to hygienic polished Ra < 0.8 μm and UltraPure polished or electro-polished Ra < 0.51 μm for the most demanding sterile applications.

Serviceability from outside the tank

The detachable shaft and spider-type coupling allow shaft seals, bearings, and other wearing parts to be replaced without entering the vessel. For operators, this translates to faster turnarounds, fewer confined-space interventions, and more uptime across the production calendar. Stainless steel parts throughout the service area resist corrosion and simplify dismantling.

Compliance and documentation

The ALT meets EHEDG, USDA, FDA, and 3-A Sanitary Standards, with an ATEX-certified version available for explosive atmospheres. The Alfa Laval Q-doc documentation package, 3.1 material certificates, and FDA 21 CFR177 conformity statements on wetted steel and elastomer parts support qualification and validation workflows in regulated industries.

Euroflow, Alfa Laval Master Distributor for southern Germany, supports tank builders, system integrators, and end users with configuration, sizing, and technical consultation to align the ALT to your specific tank geometry and process duty.