Pumps electromagnetic force

There are four (4) major types of pumps (I) positive displacement, (2) dynamic (kinetic), (3) lift, and (4) electromagnetic. Piston pumps are positive displacement pumps. The most common centrifugal pumps are of dynamic type ancient bucket-type pumps are lift pumps and electromagnetic pumps use electromagnetic force and are common in modern reactors. Canned pumps are also becoming popular in the petrochemical industiy because of the drive to minimize fugitive emissions. Figure 10-24 shows pump classification ... 

Electromagnetic Force When the fluid is an electrical conductor, as is the case with molten metals, it is possible to impress an electromagnetic field around the fluid conduit in such a way that a driving force that will cause flow is created. Such pumps have been developed for the handling of heat-transfer hquids, especially for nuclear reactors. 

The thermal-convection loops are limited to flow velocities up to about 6 cm s . Where higher velocities are required, the liquid must be pumped, either mechanically or electromagnetically the latter is usually preferred as it avoids the problem of leakage at the pump seal. Basically, these forced-convection systemsconsist of (c) a hot leg, where the liquid metal is... 

An additional advantage of the integrated circuit technology is the ability to integrate the various components, such as the transducer, reactor, valve, pump etc., within the electronic system, forming refined flow-analysis systems on silicon wafers. Several approaches, such as electrostatic, electromagnetic, piezoelectric, thermopneumatic and thermoelectric can be employed for force transduction in the microvalves, these are also applicable to micropumps. Based on these approaches, two versions of micropumps have been developed. These are connected in parallel the first pump (dual pump) is activated with periodic two-phase voltage, while the second pump (the buffer pump) is driven by two piezoelectric actuators. Microsensors of two kinds are described below a thermopile based- and a thermistor based microbiosensor. 

Electrostatic fields (dc or ac) are applied in many different ways to dielectric fluids. Generally speaking, electrostatic fields can be directed to cause greater bulk mixing of fluid in the vicinity of the heat transfer surface, which enhances heat transfer. An electrical field and a magnetic field may be combined to provide a forced convection or electromagnetic pumping. 

Magnetic pumps are pumps using electromagnetic or magnetic fields to actuate and control fluid motion in microchannels. The application of electromagnetic or magnetic forces is a flexible way of manipulating fluids in lab-on-a-chip devices. 

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