Pumps are usually categorized in two major groups: conventional-sealed pumps and seal-less pumps. The first group contains pumps that need a seal system, usually in the form of a mechanical seal. The second group includes all types and models of seal-less pumps; these pumps do not require a seal. Magnetic-driven pumps are an important class of seal-less pumps. They are used for services in which leaks cannot be tolerated or liquids are difficult to seal.
Magnetic drive pumps, or mag-drive pumps, are specialized industrial pumps that employ magnetic coupling to transmit torque from the motor to the impeller and eliminate the need for a mechanical seal. It leverages the attractive and repulsive forces of permanent magnets to create a hermetically sealed, non-contact transfer of energy between the motor and pump components.
Magnetic-drive (Mag-drive) pumps offer an innovative solution for chemical process pumping by eliminating the need for shaft seals. It significantly lowers the pump's initial expenses and ongoing operational costs because there is no need for mechanical seals, seal-fluid pots, or cooling lines.
The motor and pump drives are connected through a magnetic link that operates via an isolation shroud. Essentially, the incurred design ensures no direct or indirect pathways for fluids or gases to leak, which minimizes risks to operators and the surrounding environment.
A magnetic drive pump operates by utilizing a balanced magnetic field to generate the rotation of the liquid impeller. It differs from a conventional centrifugal pump, which employs a direct drive connection between the impeller and motor, and incorporates a magnetic field.
An external magnetic bell housing is positioned at the end of the pump shaft; the bell is situated on the exterior of the rear casing. The pump impeller is linked to a smaller magnet assembly supported by an internal shaft and bushing assembly. Notably, there is no need for a mechanical seal since all liquid-end components are contained within the fluid head of the pump.
The smaller magnet assembly is placed at the center of the magnetic field generated by the external bell housing. Even though a fluid barrier separates the two magnet assemblies, their magnetic fields remain aligned. When the pump motor starts, the external bell housing starts to rotate, causing the rotation of the magnetic field to impact the inner impeller magnet. As both magnets rotate in unison, the impeller spins and moves fluid throughout the system.
