Magnetic Drive Coupling & Mixers

A magnetic drive stirrer transmits torque from an external motor to the agitator shaft inside a pressure reactor through a closed containment wall. The shaft never penetrates the pressure boundary, so no packing gland or mechanical seal can leak or wear. Coretest supplies magnetic couplings and stirrer drive assemblies for new reactors and retrofits, from 50 mL to industrial scale.

What the range covers

• Magnetic Drives For High Pressure M, MM, MG and MMG Series: 0.78 to 936 N-m, 200 bar standard, 350 bar optional
• Magnetic Couplings (LEBMD): 50 to 5400 Ncm, full vacuum to 500 bar, -50 °C to +500 °C, ATEX versions
• High Torque Magnetic Drives for Stirred Reactors: 16 to 120 in-lb, to 5000 psi (345 bar)
• Top Entry Sealless Magnetic Agitator Drive (TESMADKPR), 10 to 500 L, to 300 bar
• Metal-Free/Inert Stirrer Drives, ceramic, full vacuum to 60 bar, to 250 °C

Engineering features

The coupling has an outer rotor with permanent magnets and an inner rotor on the stirrer shaft inside a sealed chamber. Magnetic flux crosses the chamber wall and the inner shaft turns synchronously with the outer rotor. Neodymium-iron-boron magnets give about 25 percent more coupling force than samarium-cobalt; under overload the coupling slips rather than stalling the motor.

The inner shaft runs in graphite-filled PTFE bushings, the outer rotor on twin sealed ball bearings. Wetted parts are SS-316L as standard, with Hastelloy B/C, Inconel, titanium, zirconium and tantalum; the metal-free version uses ceramic wetted parts. A water cooling sleeve or jacket protects magnets and bushings when the reactor runs to 500 °C.

Drives are supplied with an in-line AC motor and speed controller, a belt drive for higher torque, or an ATEX or explosion-proof motor. Pilot drives mount to the head by flanged joint. Reference speeds run to 1450 rpm on laboratory drives and 750 rpm on 10 to 100 L belt drives.

Selecting a configuration

To select or retrofit a drive Coretest needs:

• Reactor volume, head port and existing gland dimensions
• Design pressure and temperature at the head
• Process medium: viscosity, solids, hydrogen, oxygen or toxic gas
• Required torque and speed, or impeller type and diameter
• Cooling: water available, or air only
• Motor: in-line AC, belt drive, ATEX or explosion-proof
• Materials and certification: wetted alloy, ceramic, ATEX or CE

Typical applications

• Hydrogenation reactors with no hydrogen leakage at the shaft
• Oxygen, chlorine and toxic gas reactions
• High vacuum distillation
• Retrofit of packed gland stirrers
• Fermenters and glass-lined reactors with metal-free drives

Reference values above describe the product family. Guaranteed performance, included hardware, exclusions, interfaces and acceptance criteria are stated only in the project-specific technical proposal and approved datasheet.