IKA LR 1000.11 anchor stirrer, stainless steel, for LR 1000, 0004663000

Macroscopic mixing and near-wall kinetics

In the process engineering formulation of highly viscous, pasty or structurally viscous media (such as gels, dense emulsions or polymer suspensions), conventional axial agitators reach their physical limits. In viscous fluids, they merely create local flow cavities, whilst the remainder of the sample matrix stagnates against the reactor wall. The IKA LR 1000.11 anchor stirrer is geometrically designed to precisely match the cylindrical dimensions of the LR 1000 laboratory reactor. Thanks to its U-shaped, wall-proximate design, the stirrer engages with the medium throughout the entire reactor volume. The rotation of the anchor primarily induces tangential and radial flow fields. These shear stresses break down the fluid’s viscosity along the shear gradient, forcing the material near the wall into mass transfer and virtually eliminating fluid-mechanical dead zones.

Thermodynamic convection in viscous matrices

Even without the use of direct physical wall scrapers (as in the LR 1000.10 model), the geometry of the LR 1000.11 massively improves the thermodynamic efficiency of the reactor system. The rotation close to the wall generates microscopic turbulence in the thermal boundary layer between the reactor wall and the medium. This constant physical exchange of molecular layers continuously draws the fluid, heated by the heating block, into the cooler reactor core. This significantly increases the convective heat transfer coefficient (k-value), drastically minimises temperature gradients within the 1000-ml volume and proactively protects thermolabile analytes from local denaturation.

Absolute chemical inertness thanks to a single-material design

An outstanding analytical advantage of the LR 1000.11 is the complete absence of polymer components or elastomers. The entire stirrer – from the drive shaft to the anchor blades – is manufactured from solid, corrosion-resistant AISI 316L stainless steel (material number 1.4404). This molybdenum-alloyed austenitic steel offers unrivalled chemical inertness. The anchor stirrer can be used without hesitation in highly aggressive media, concentrated organic solvents, strong acids or at extreme pH values, where stirring elements containing PEEK or PTFE components would be chemically attacked or could swell.

GLP-compliant sterilisation and hygiene

The absence of wear-prone wiper lips or complex mechanical joints makes the LR 1000.11 a highly hygienic piece of equipment. The smooth, electropolished stainless steel surfaces offer no microscopic surfaces for bacterial biofilms or stubborn chemical residues to adhere to. To ensure strict compliance with GLP/GMP hygiene guidelines, the stirring element can be thermally sterilised in an autoclave at 121 °C (or higher) an unlimited number of times, or thoroughly decontaminated in aggressive ultrasonic baths.

Technical details

• Product type: Anchor stirrer (without scraper)
• Fluid dynamics design: For highly viscous, laminar and paste-like media
• Design principle: Rotation close to the wall to generate tangential flows
• Thermodynamic advantage: Promotion of convective heat transfer within the reactor
• Compatibility: Exclusively for IKA LR 1000 laboratory reactor systems
• Material: Solid AISI 316L stainless steel (material no. 1.4404)
• Chemical resistance: Complete resistance to organic solvents and aggressive acids
• Wear parts: None (no polymers used whatsoever)
• Max. permissible operating temperature: 120 °C (limited by the reactor system)
• Hygiene: Fully autoclavable and chemically sterilisable

Scope of supply

• 1 x IKA LR 1000.11 anchor stirrer (stainless steel)

(Important note: The IKA LR 1000 reactor vessel and the base station are not included in the scope of delivery!)

Customised requirements & accessories

The LR 1000.11 anchor stirrer is the mechanical mixing element and must be operated in conjunction with an IKA LR 1000.1 or LR 1000.3 reactor vessel. If you require even more thorough thermodynamic mixing of the boundary layer when working with extremely sticky resins or those prone to scorching, we recommend switching to the LR 1000.10 model with active PEEK scrapers. Please contact our procurement service at any time for the rheologically correct design of your reaction vessels.