IKA LR 1000.10 anchor stirrer with PEEK scrapers, for LR 1000, 0004663100

Rheology and fluid mechanics of highly viscous media

In chemical reaction engineering and cosmetic formulation, media with high structural viscosity or a paste-like consistency (such as highly concentrated polymer solutions or dense emulsions) tend to form laminar flow profiles. Conventional propeller or turbine agitators fail in these systems, as they only circulate the medium locally at the centre, whilst the fluid near the walls stagnates. The IKA LR 1000.10 anchor stirrer solves this rheological problem through its reactor-specific geometry. The solid stainless-steel anchors rotate with a minimal clearance along the cylindrical inner wall of the LR 1000 laboratory reactor. This wall-adjacent kinetics induces immense radial and tangential shear stresses in the medium, which locally reduce the viscosity in the shear gradient and homogenise the entire 1000-ml reactor contents in a circular pattern, thereby physically eliminating fluid dynamic dead zones.

Thermodynamic optimisation using PEEK scrapers

The fundamental problem with temperature control of highly viscous fluids in heated reactors is the formation of a highly insulating thermal boundary layer on the reactor wall. Without constant mechanical renewal of this layer, drastic temperature gradients, localised overheating (hotspots) and, in the worst case, irreversible thermal denaturation (burning) of the product near the wall occur. The LR 1000.10 is equipped with flexible scraper blades made of PEEK (polyetheretherketone) to resolve this thermodynamic bottleneck. During operation, these high-temperature-resistant polymer lips continuously scrape along the borosilicate glass wall of the reactor. They mechanically scrape away the static, heated fluid and force it to mix with the cooler reactor core. This process maximises the system’s convective heat transfer coefficient (k-value) and guarantees an absolutely homogeneous temperature distribution throughout the entire sample matrix.

Material integrity and chemical resistance

To ensure absolute analytical purity in GLP- and GMP-regulated synthesis environments, the materials of the stirring mechanism are designed to withstand the most extreme chemical and thermal stresses. The central shaft and the anchor blades are made of solid, corrosion-resistant AISI 316L stainless steel (material number 1.4404). The flexible scrapers are made of PEEK, a semi-crystalline, high-performance thermoplastic which remains extremely dimensionally stable even at high process temperatures (up to 120 °C in the LR 1000) and exhibits outstanding chemical resistance to aggressive organic solvents, acids and alkalis.

Modular cleaning and decontamination

The risk of microbiological cross-contamination (carry-over) or chemical residues is particularly high when processing sticky resins or greasy gels. The LR 1000.10 anchor stirrer can be mechanically dismantled for thermal sterilisation (autoclaving) or intensive chemical cleaning. The PEEK scrapers can be easily removed from the stainless steel shaft for separate decontamination or replacement as wear parts.

Technical details

• Product type: Anchor agitator with flexible scrapers
• Fluid dynamics design: Optimised for extremely high-viscosity and paste-like media
• Distinctive feature: Integrated, wall-skimming PEEK blades
• Thermodynamic advantage: Significant increase in convective heat transfer at the reactor wall
• Compatibility: Exclusively for IKA LR 1000 laboratory reactor systems (basic and control)
• Material (shaft & rotor): High-grade AISI 316L stainless steel (material no. 1.4404)
• Material (scrapers): PEEK (polyetheretherketone)
• Chemical resistance: Maximum resistance to solvents, acids and alkalis
• Max. permissible operating temperature: 120 °C (system limit of the LR 1000)
• Hygiene: Scrapers can be removed for intensive chemical or thermal cleaning

Scope of supply

• 1 x IKA LR 1000.10 anchor stirrer (stainless steel)
• 1 x set of PEEK scrapers (already fitted to the anchor stirrer)

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

Individual requirements & accessories

The anchor stirrer is a purely mechanical component and must be used in an IKA LR 1000.1 or LR 1000.3 reactor vessel. The flexible PEEK scrapers are subject to mechanical wear when used with highly abrasive media (such as particle-laden pastes). We recommend keeping a stock of suitable replacement scrapers for your routine operations to minimise downtime. Please contact our procurement service at any time for the fluid dynamics design of your reactor and the procurement of suitable wear parts.