09-01-2014, 12:42 PM
Electromagnetic pump
Electromagnetic pump.docx (Size: 565.73 KB / Downloads: 53)
INTRODUCTION
A hydraulic machine in which energy is transmitted from the working members (runners, piston and others) to the flowing liquid and the energy of the liquid at the inlet of the hydraulic machine is less than the outlet energy are referred as pumps. Pump is a device that expends energy in order to raise, transport, or compress fluids. A pump can also be defined as a hydraulic machine, which converts the mechanical energy into hydraulic energy. Pumps find application in hydroelectric power plants, irrigation and water supply systems, and also in thermal nuclear and pumped storage stations. In addition, pumps are widely used in construction of hydraulic structures, such as dams, canals, river and seaports, and others.
FLEMING’S LEFT HAND RULE
The relation among the direction of a magnetic field, the direction of a current in that field, and the direction of the resulting motion of the conductor carrying the current can be determined by using Fleming’s Left Hand Rule.
It states that “With the forefinger, middle finger, and thumb mutually perpendicular, point the forefinger in the direction of the field or flux, the middle finger in the direction of the current in the conductor, and the thumb will point in the direction in which the conductor tends to move”.
ELECTROMAGNETIC PUMP
Electromagnetic Pumps (EMP) are powerful and can be reversed instantly, providing metal circulation and scrap melting systems with no moving parts. EMP uses the principle of electromagnetics to circulate molten metal. The proper bath circulation ensures effective heat transfer from the combustion space to the bath, minimizing dross formation and improving the thermal efficiency of the furnace. Melt cycle times can also be reduced by using the EMP charge well which will improve the melt rate. The furnace can be sampled and some types of scrap and alloying elements can be added without opening furnace door.
The design of the original EMP charge well provided for excellent bath circulation in the furnace, but the metal action in the charge well was more of a churning action. This allowed for some heavy type scrap and alloying elements to be added in the charge well, however problems arose when very light gauge scrap was charged. The original design did not have a strong submergence action, limiting customers from charging light guage scrap. This design reduced opportunities of financial savings to the customers. The electromagnetic pump is based upon a linear motor, a principle well developed and widely used throughout industry. The metal acts as the rotor while the coil acts as the stator.
ENVIRONMENTAL
The EMP System gives many environmental advantages due to its unique design. The external EMP charge well allows for the addition of many scrap types and other additions to the aluminium bath while keeping the furnace door closed. Alloying additions (both pure and as master alloys), fluxes and gas injection can all be accomplished while keeping the furnace door closed. This has the obvious benefits of minimizing fume emissions from excessive door openings, maintaining the furnace temperature and minimizing the amount of air entering the furnace from door openings.
Light gauge scrap can be charged very efficiently into the vortex without the need for salt fluxes, eliminating the need for salt slag disposal. By efficient submergence of scraps fed into the patented vortex, dross is reduced again reducing the quantities of dross requiring treatment prior to disposal in the environment.
CONCLUSION
The electromagnetic pump works by Faraday’s principle. It does not have moving parts which enhances its reliability. This kind of pump drives the flow of liquid metal or any fluid with high electric conductivity. As it was shown in this paper this kind of pump offer no great resistance to the fluid flow because it has no impellers. This facilitates the natural circulation of the fluid and enhances its safe passivity feature. For that, this kind of pump is desired to be present in the new fast reactor designs.
An electromagnetic pump based on the above mentioned theory has been developed. The pump design needs to be optimized for optimum efficiency .The rotor’s angular velocity and Magnetization strength of the magnets have direct bearing on the Lorentz force developed, Whereas magnet pitch optimization need further qualitative and quantitative analysis and Optimization.