Silverson L5T Laboratory High-Shear Mixer
| Brand | Silverson |
|---|---|
| Origin | United Kingdom |
| Model | L5T |
| Instrument Type | Probe-type Rotor-Stator Homogenizer |
| Dimensions (W×D×H) | 230 × 280 × 560 mm |
| Processing Volume Range | 1 mL – 12 L |
Overview
The Silverson L5T is a precision-engineered laboratory-scale high-shear mixer based on the proven rotor-stator principle. It operates via controlled hydrodynamic cavitation and intense mechanical shear generated within a precisely engineered gap between a high-speed rotating rotor and a stationary perforated stator. This four-stage mixing mechanism—(1) axial aspiration of material into the workhead, (2) radial acceleration into the rotor–stator clearance zone, (3) hydraulic shearing through stator orifices at velocities exceeding 20 m/s, and (4) tangential ejection establishing a closed-loop circulation—enables rapid particle size reduction, uniform dispersion, stable emulsion formation, and complete dissolution across viscous and heterogeneous systems. Designed for reproducible scalability from benchtop to pilot scale, the L5T serves as a critical tool in formulation development, quality control, and process optimization where conventional stirrers or magnetic mixers fail to deliver sufficient energy input or spatial homogeneity.
Key Features
- Electronic infinitely variable speed control (0–8,000 rpm no-load; 6,000 rpm under full load), enabling precise adjustment to match rheological demands of diverse samples—from low-viscosity aqueous solutions to highly structured gels and suspensions.
- Integrated motorized lift column with push-button actuation, ensuring ergonomic operation and repeatable immersion depth control without manual repositioning.
- All wetted components constructed from 316 stainless steel, bronze alloy, or PTFE—fully compliant with ISO 8503-2 surface roughness standards and suitable for cleaning-in-place (CIP) protocols.
- Dual-fan-cooled, brushless induction motor rated for continuous duty at ambient temperatures up to 40 °C, delivering thermal stability and acoustic noise below 72 dBA at 1 m distance.
- Universal probe-mounting interface compatible with four standardized Silverson workheads: General-Purpose (3.5 cm OD, 0.9 cm orifice), Vertical-Flow (5.0 cm OD), Multi-Hole Fine (3.5 cm OD, 0.2 cm orifice), and Multi-Round Orifice (3.3 cm OD, 0.13 cm orifice)—each optimized for distinct shear intensity and flow profile requirements.
Sample Compatibility & Compliance
The L5T accommodates sample volumes from 1 mL to 12 L in standard cylindrical or conical glass or stainless-steel vessels. It processes Newtonian and non-Newtonian fluids—including polymer solutions, colloidal dispersions, oil-in-water/water-in-oil emulsions, ceramic slurries, pharmaceutical suspensions, and food-grade pastes—without foaming or excessive air entrapment due to its radial ejection design minimizing surface turbulence. The system conforms to ISO 27327:2011 (Laboratory equipment — Homogenizers — Performance requirements and test methods) and supports GLP/GMP documentation workflows through optional audit-trail-capable controllers (when integrated with third-party data acquisition systems). All electrical components meet CE/UKCA marking requirements per EN 61000-6-3 (EMC) and EN 61000-6-2 (immunity).
Software & Data Management
While the base L5T model features analog speed control and mechanical ON/OFF switching, it is fully compatible with external digital interfaces via 0–10 V analog output and TTL-compatible pulse signals for RPM feedback. When paired with Silverson’s optional L5 Series Digital Controller (sold separately), users gain access to programmable timer functions (0.1 s–99 h 59 min), real-time amperage monitoring (for torque-based endpoint detection), and rotational speed logging at 1 Hz resolution. Data export is supported via USB or RS-232 to CSV-compatible platforms, facilitating integration into LIMS environments and compliance with FDA 21 CFR Part 11 when used with validated electronic signature modules.
Applications
- Pharmaceutical: Preparation of nanoemulsions, microsuspensions, and lyophilization pre-formulations; dissolution testing of poorly soluble APIs; viscosity-modified gel bases.
- Food & Beverage: Stabilization of dressings, sauces, and dairy alternatives; reduction of fat globule size in plant-based milks; homogenization of fruit pulps and nut butters.
- Materials Science: Dispersion of carbon nanotubes, graphene oxide, or metal oxides in polymer matrices; deagglomeration of pigment concentrates; slurry conditioning for battery electrode coating.
- Chemical & Cosmetics: Synthesis of silicone emulsions, wax-in-water systems, and surfactant micellar solutions; breakdown of agglomerated thickeners (e.g., xanthan, carbomer).
FAQ
What is the minimum recommended sample volume for reliable operation?
For consistent shear delivery and avoidance of vortex formation, a minimum working volume of 50 mL is advised when using the General-Purpose workhead in a 100 mL beaker. For volumes below 10 mL, specialized micro-workheads (not included with L5T) are required.
Can the L5T be used with corrosive solvents such as chlorinated hydrocarbons or strong acids?
Yes—provided the selected workhead material (e.g., PTFE-lined stator or Hastelloy rotor option) matches chemical compatibility charts. Standard 316 SS is resistant to most organic solvents but not hydrochloric or hydrofluoric acid.
Is validation support available for regulated environments?
Silverson provides IQ/OQ documentation templates aligned with ASTM E2500-13 and ISO/IEC 17025. Installation qualification includes dimensional verification, electrical safety testing, and baseline performance mapping against reference viscosity standards.
How does the L5T compare to ultrasonic homogenizers for nanoparticle dispersion?
Unlike ultrasonic systems that rely on transient cavitation, the L5T delivers sustained, controllable shear energy with superior heat dissipation—making it more suitable for thermally sensitive formulations and scalable to production-grade rotor-stator systems without re-optimization.
