The Alfa Laval ALS hygienic side-mounted agitator is engineered around a configurable platform that combines a drive unit with bearing frame, a shaft with a dedicated seal arrangement, and an energy-saving EnSaFoil impeller. Each element is sized to the tank geometry, product properties and agitation task, so the unit performs efficiently across a broad envelope of hygienic mixing duties rather than being forced into a one-size-fits-all package.

How the EnSaFoil impeller delivers energy-efficient mixing

The EnSaFoil propeller is offered with two or three blades and in diameters from Ø125 mm to Ø1900 mm, giving designers fine control over flow and shear. Its high-efficiency profile produces a strong axial pumping effect, generating high flow at low shear so that sensitive products — cream, drinking yoghurt, flavoured milk mixes, juices, fermenting media — are handled gently. The wide range of propeller and drive combinations lets you target the lowest practical energy consumption for the duty, supporting lower operational costs over the life of the equipment.

Modular drive, seal, shaft and foil architecture for sanitary mixing agitator duties

The ALS configuration is divided into four primary elements: drives (drive unit, shaft support and shaft diameter), seal arrangements (oil trap and shaft seal type), shaft (length to suit the tank), and Energy Saving Foils (propeller type and surface finish). Six drive variants are available, including a stainless steel bearing frame with right-angle gearbox, a bearing frame with coaxial gearbox, a bearing frame with direct motor drive, a right-angle gearbox with hollow-shaft mounting, a parallel shaft gearbox with hollow-shaft mounting, and a direct motor drive with lantern, seal flange and single mechanical bellow seal. This breadth means a single product family can be specified for a wide range of tanks and process conditions.

Built for CIP cleanability and hygienic compliance

The ALS is designed so that cleaning is built in, not bolted on. The stainless steel bearing frame uses an O-ring seal suitable for external wash down. Internal parts have no plane surfaces or grooves, no shadow sides between the blades, and smooth surfaces that drain freely. Because the bearing frame drive uses a special internal shaft connection, there is no flange coupling inside the tank, eliminating a known risk zone in hygienic agitation. Product-wetted finishes are available from industrial shot peened Ra < 3.2 μm through hygienic polished Ra < 0.8 μm to UltraPure polished or electro-polished Ra < 0.51 μm.

Low-maintenance service from outside the tank

All service tasks — including replacement of wear parts such as shaft seals and bearings — can be performed from outside the tank. The detachable shaft can be dismounted externally, and the spider-type coupling together with stainless steel components simplifies dismantling and resists corrosion. The result is more uptime, lower labour cost, and reduced production disruption during planned maintenance.

Sterile, aseptic and explosive-atmosphere duties

For high-pressure and aseptic processes, the ALS can be specified with a double mechanical seal. For potentially explosive environments, an ATEX-certified version is available. Combined with the choice of EPDM or FPM elastomers, Carbon (FDA) and Silicon carbide mechanical seal faces, and AISI 316L wetted parts, the platform covers duties ranging from milk storage and UHT tanks through syrup, powder and oil dispersion to crystallizing tanks and dimple-jacket heat transfer circulation.