An electromagnetic pump is most often a device that uses electromagnetism to create flow in magnetically charged materials such as liquid metal. These kinds of pumps can be useful for many materials, including non-metal elements such as potassium. One important function of these pumps is to cool nuclear reactors, though some other applications can be considered common. Magnetic fields used to create flow have some significant benefits over mechanical pumps. Different types of pumps might be used in specific situations because of the benefits they offer.
In general, magnetic fields are created inside an electromagnetic pump using permanent magnets or electromagnets. To achieve the required flow, high electrical currents or temperatures must be established. The magnets can be configured to create a specific directional flow, depending on the application. Materials that are often considered difficult to handle, such as liquid metal, will usually flow in a predictable and continuous direction inside an electromagnetic pump.
Common materials passed through an electromagnetic pump include metals such as aluminum and mercury. Other magnetically charged elements passed through an electromagnetic pump can include zinc, sodium and potassium. Different elements usually require different pump configurations and temperatures. They also are used for specific applications.
Electromagnetic pumps are often used to cool nuclear reactors. Extreme temperatures in nuclear environments often require high-tolerance cooling mechanisms, and an electromagnetic pump is considered best in such situations. Magnetic fields also can be used in foundry work, where high-temperature metals must be poured or otherwise transported from one location to another. In this regard, an electromagnetic pump also can work as a flow meter when mechanical devices might be insufficient.
Despite the specific requirements that can create flow in these materials, there are common advantages that electromagnetic pumps have over mechanical pumps. There are often no moving parts required to create material flow, so there is little resistance and less stress on the machinery. This unrestricted flow can be considered more reliable than many other methods and has been shown to last in high-stress situations for extended periods.
Variations of the electromagnetic pump process can include direct current conduction, alternating current (AC) conduction and linear induction. Direct current conduction pumps are often used for high-temperature situations and require high amounts of power. Alternating current conduction pumps depend on AC power and produce flow using transformer configurations. Linear induction pumps also use AC power passed through specific magnetic windings to create a traveling magnetic field that creates flow.