Magnetic-drive reactors incorporate a magnetic coupling sealing system into the design of conventional reactors. Their core structure comprises six major components that work in synergy to ensure leak-free operation:
Reactor Vessel: Serves as the pressure-bearing reaction chamber. Materials are selected based on process requirements-such as stainless steel (304, 316L), titanium alloys, Hastelloy, or glass lining-with the inner wall polished (roughness Ra ≤ 0.4 μm) to prevent residue buildup and facilitate cleaning. Standard volumes range from 0.01 m³ to 50 m³, with options for custom-built, ultra-large capacity units.
Magnetic Drive System: A core component consisting of an inner magnet assembly, an outer magnet assembly, and an isolation sleeve:
Inner Magnet Assembly: Mounted at the top of the internal agitator shaft; utilizes high-strength NdFeB (neodymium-iron-boron) magnets (magnetic energy product ≥ 45 MGOe) encased in a corrosion-resistant protective sheath (e.g., titanium alloy or PTFE) to prevent direct contact with the reaction medium;
Outer Magnet Assembly: Connected to the motor; drives the rotation of the inner magnet assembly via magnetic force. The number of magnets matches that of the inner assembly to ensure stable torque transmission;
Isolation Sleeve: A critical sealing component positioned between the inner and outer magnet assemblies. It requires materials that offer both high strength and corrosion resistance (commonly Hastelloy C276 or titanium alloy TA2). Its thickness is determined by the design pressure (typically 3–8 mm) to ensure it can withstand internal vessel pressure while allowing magnetic flux to pass through.
Agitation System: Comprises the agitator shaft and impeller. The shaft is rigidly connected to the inner magnet assembly and made of the same material as the vessel body. Impeller types are selected based on reaction needs-such as propeller-type (for low-viscosity media), anchor-type (for high-viscosity media), or turbine-type (for reactions requiring high shear force). Some units feature dual-layer impellers to achieve multi-zone mixing.
Heat Exchange System: Utilizes jacketed, internal coil, or external half-pipe heat exchange configurations. Heat exchange media-such as steam, thermal oil, cold water, or chilled brine-are circulated to achieve precise control of the reaction temperature. Some high-end units are equipped with intelligent temperature control systems that monitor and automatically adjust the flow rate of the heat exchange medium in real-time. Inlet and Outlet Systems: The inlet is equipped with a check valve and a filter to prevent backflow and the entry of impurities. The outlet features a bottom or side discharge design with a quick-opening valve, ensuring rapid discharge without residue; certain models can be fitted with an in-line sampling port to enable leak-free sampling during the reaction process.
Control Systems: These include temperature control (via thermocouples or platinum resistance thermometers), pressure control (using pressure gauges and safety valves), and rotational speed control (variable-frequency motor for adjusting agitation speed within the 50–1500 rpm range). High-end models can be equipped with a PLC control system to enable fully automated operation and remote monitoring.