Abstract:
Electromagnetic helical pump for high-temperature transportation of molten metal, comprising an explicit-pole or implicit-pole inductor exciting a rotating magnetic field (RMF), and a helical channel consisting of a thick-wall ceramic pipe with a quick-change helical core made of graphite or graphitized carbon. The pump can be used for transportation and batching of molten aluminum, magnesium, copper, etc. and their alloys.

Description:
This application claims the benefit of U.S. provisional patent application No. 60/546,113, filed Feb. 18, 2004, which is hereby incorporated by reference herein in its entirety. 

   BACKGROUND OF THE INVENTION 
   The present invention relates generally to electromagnetic helical pumps, and more particularly to electromagnetic helical pumps for high-temperature transportation of molten metals. 
   Electromagnetic helical induction pumps are well known. See, for example, Olich et al. U.S. Pat. No. 4,212,592 and Lauhoff et al. U.S. Pat. No. 4,775,298, each of which is hereby incorporated by reference herein in its entirety. Particular design modifications to these types of pumps make it possible to transport melts of certain metals and alloys (mainly alkali and alkaline-earth metals) at temperatures up to 800° Celsius. 
   However, previous designs have been inapplicable for certain aggressive metals, such as liquid copper, aluminum, or their alloys, since helical channels in such pumps have been stationary and made of nonmagnetic steel that rapidly erodes from the motion of these metals. Currently, no serviceable designs of helical pumps for molten aggressive metals (e.g., copper, aluminum, etc.), or alloys thereof, are known. 
   Accordingly, it would be desirable to provide electromagnetic helical pumps for high-temperature transportation or batching of such aggressive molten metals. 
   SUMMARY OF THE INVENTION 
   It is, therefore, an object of this invention to provide electromagnetic helical pumps for high-temperature transportation of molten metals. 
   It is also an object of this invention to provide such pumps with quickly replaceable helical cores. 
   In accordance with one embodiment of the present invention, there is provided an electromagnetic helical pump for high-temperature transportation of molten metal that includes an inductor exciting RMF and a helical channel, wherein the helical channel is made of a ceramic pipe and a quick-change helical core made of graphite or graphitized carbon. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other advantages of the invention will be more apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which: 
       FIG. 1  is a vertical cross-sectional view of one embodiment of an electromagnetic pump constructed in accordance with the present invention, taken from line I-I of  FIG. 2 ; 
       FIG. 2  is a horizontal cross-sectional view of the electromagnetic pump of  FIG. 1 , taken from line II-II of  FIG. 1 ; 
       FIG. 3  is a vertical cross-sectional view of a furnace incorporating the electromagnetic pump of  FIGS. 1 and 2  in accordance with the present invention; 
       FIG. 4  is a vertical cross-sectional view of an other embodiment of an electromagnetic pump constructed in accordance with the present invention, taken from line IV-IV of  FIG. 5 ; 
       FIG. 5  is a horizontal cross-sectional view of the electromagnetic pump of  FIG. 4 , taken from line V-V of  FIG. 4 ; and 
       FIGS. 6 and 6A  schematically illustrate superwaving wave phenomena. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The present invention provides electromagnetic helical pumps for high-temperature transportation of molten metals. The proposed helical pump design can be used for transportation or batching of aggressive melts with temperatures above 1000° Celsius. 
   The pump includes a helical channel or passageway, through which the molten metals can flow, and a magnetic circuit for generating a rotating magnetic field (“RMF”) in the helical channel. The magnetic field rotation axis is coaxial with the central axis of the helical channel, such that RMF is excited in the helical channel and induces a rotating current density field in the liquid metal. The interaction of this field with RMF generates tangential electromagnetic body forces that create electromagnetic pressure in the helical channel of the pump. This pressure displaces the molten metals upwards in the helical channel. 
   In accordance with one aspect of this invention, a thermo-stable helical channel of the pump is preferably provided by a helical space to be filled with molten metal created between a replaceable graphite or graphitized carbon core, which is preferably reinforced and supported by a steel rod, and a thick-walled ceramic pipe, whose material preferably does not rapidly erode from the motion of the molten metals. 
   Since graphite and graphitized carbon still erode over time, the pump design of a preferred embodiment of this invention may provide for a quick replacement of the helical core. 
   Referring to  FIGS. 1 and 2 , a preferred embodiment of an electromagnetic pump constructed in accordance with the present invention is shown. Pump  100  includes a magnetic circuit or inductor  10  and a helical channel  50 . Inductor  10  may preferably be made of electrotechnical steel sheet  20 , and a plurality of RMF excitation coils  30  made of copper or aluminum electrically insulated wire or electrically insulated copper tube of circular or rectangular cross-section, for example. 
   Helical channel  50  may preferably include a ceramic pipe  60  having a longitudinal axis  65 , and a helical rod  70  made of graphite or graphitized carbon, for example, with a thin steel central rod  80  arranged thereinside that is concentric with pipe  60  about axis  65 . In other embodiments of the present invention, central rod  80  may be made of any metals and alloys or metalloceramics with a melting temperature above that of the pumped melt. Central rod  80 , whose diameter may be much smaller than the internal diameter of the helical channel on rod  70 , is arranged for reinforcing, mounting, and dismantling helical rod  70 . Helical passageway or channel  90  is thereby provided by the space created along helical rod  70  between pipe  60  and central rod  80 . 
   As shown in  FIGS. 1 and 2 , pipe  60  may be threaded such that helical rod  70  may be screwed into and out of core  50  along axis  65  by turning helical rod  70  in the clockwise direction of arrow  82  and in the counter-clockwise direction of arrow  84 , respectively. This enables quick replacement of helical rod  70 , which may be desirable because graphite and graphitized carbon can erode over time. In an other embodiment of the present invention, pipe  60  and rod  70  may create a tight fit that obviates the need for threading but still enables quick replacement of helical rod  70 . 
   Central rod  80  may be rigidly coupled to helical rod  70  and may serve to remove helical rod  70  out of channel  50 . Jacket  40 , which may preferably be made of thin nonmagnetic steel, or any other suitable material, may isolate inductor  10  from the furnace lining and channel  50 , and may be arranged for air cooling of the windings and magnetic core of inductor  10 . 
   Referring to  FIG. 3 , in accordance with the present invention, pump  100  can be placed into discharge lip  210  of a furnace  200  so that the turns of helical channel  90  at inlet  92  located inside RMF are partially filled with molten metal  220 . 
   When the pump excitation windings  30  are connected to a three-phase voltage power supply (not shown), RMF is excited in helical channel  90  and induces a rotating current density field in the liquid metal  220 . The interaction of this field with RMF generates tangential electromagnetic body forces creating electromagnetic pressure in helical channel  90  of pump  100 , which displaces melt  220  upwards in the direction of arrow  225  along axis  65  of pump  100  from inlet  92  to outlet  94 . 
   In a preferred embodiment, air cooling of inductor  10  may be realized by air blown through jacket  40 . As shown in  FIGS. 1-3 , compressed air for cooling inductor  10  may be fed into and out of jacket  40  via air inlet  42  and air outlet  44 . 
   Referring to  FIGS. 4 and 5 , an other embodiment of an electromagnetic pump constructed in accordance with the present invention is shown. Pump  300  includes a magnetic circuit or inductor  310  and a helical channel  350 . Inductor  310  may preferably include ferroceramic elements  320 , and a plurality of RMF excitation coils  330  made of any suitable type of thermo-stable ceramic boxes, for example. Inside the boxes, helical channels may be provided and filled with solid or liquid metal, whose melting temperature is lower than the temperature of the lining surrounding the inductor, and whose boiling temperature is higher than the temperature of the lining. Electrodes for electric current supply are preferably fixed at the ends of the helical channel. In other embodiments of the present invention, inductor  310  may be made in the form of boxes of thin carbon steel filled with iron or cobalt powder, for example. 
   Helical channel  350  may preferably include a pipe  360  similar to pipe  60  of  FIGS. 1-3  having a longitudinal axis  365 , and a helical rod  370  similar to rod  70  of  FIGS. 1-3 , for example. The construction of helical channel  350  does not differ from that of helical channel  50 . Like central rod  80 , rod  380  is arranged for reinforcing, mounting, and dismantling helical rod  370 . Helical passageway or channel  390  is thereby provided by the space created between helical rod  370  and pipe  360 . Like rod  70 , rod  370  may be quickly replaced by unscrewing it from the threads of pipe  360 . 
   Jacket  340 , which may preferably be made of common carbon steel or any other suitable material, is preferably provided to surround inductor  310  and channel  350 . Jacket  340  is arranged for mechanical coupling of the elements of inductor  310  and is not meant for inductor cooling since the proposed design of inductor  310  does not require such cooling. 
   Typically sinusoidal waveforms are applied to the excitation windings (e.g., windings  30  or  330 ) of induction pumps of the type described herein such that RMF is excited in the helical channel. In accordance with an other embodiment of the present invention, instead of typical sinusoidal and square waveforms, superwaves may be generated and applied to excitation windings  30  or  330  when the windings are connected to a power supply (not shown). 
   The “superwaves” pulse pattern is in accordance with superwaving activity as set forth in the theory advanced in the Irving I. Dardik article “The Great Law of the Universe” that appeared in the March/April 1994 issue of the “Cycles” Journal. This article is hereby incorporated herein by reference. 
   As pointed out in the Dardik article, it is generally accepted in science that all things in nature are composed of atoms that move around in perpetual motion, the atoms attracting each other when they are a little distance apart and repelling upon being squeezed into one another. In contradistinction, the Dardik hypothesis is that all things in the universe are composed of waves that wave, this activity being referred to as “superwaving.” Superwaving gives rise to and is matter in motion (i.e., both change simultaneously to define matter-space-time). 
   Thus in nature, changes in the frequency and amplitude of a wave are not independent and different from one another, but are concurrently one and the same, representing two different hierarchical levels simultaneously. Any increase in wave frequency at the same time creates a new wave pattern, for all waves incorporate therein smaller waves and varying frequencies, and one cannot exist without the other. 
   Every wave necessarily incorporates smaller waves, and is contained by larger waves. Thus each high-amplitude low-frequency major wave is modulated by many higher frequency low-amplitude minor waves. Superwaving is an ongoing process of waves waving within one another. 
     FIG. 6  (adapted from the illustrations in the Dardik article) schematically illustrates superwaving wave phenomena.  FIG. 6  illustrates low-frequency major wave  110  modulated, for example, by minor waves  120  and  130 . Minor waves  120  and  130  have progressively higher frequencies (compared to major wave  110 ). Other minor waves of even higher frequency may modulate major wave  110 , but are not shown for clarity. This same superwaving wave phenomena is depicted in the time-domain in  FIG. 6A . 
   This superwaving principle of waves waving demonstrates that wave frequency and wave intensity (amplitude squared) are simultaneous and continuous. The two different kinds of energy (i.e., energy carried by the waves that is proportional to their frequency, and energy proportional to their intensity) are also simultaneous and continuous. Energy therefore is waves waving, or “wave/energy.” In accordance with the invention, the superwaving wave activity may be used to generate magnetic flux in a coil for enhanced transportation of molten metal using the helical pumps of the present invention (e.g., reduced friction, increased pumping pressure, etc.). 
   Various types of circuitries and devices made of various materials can be used to implement the pump as described above according to this invention. 
   It will be understood, therefore, that the foregoing is only illustrative of the principles of the invention, and that various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention, and the present invention is limited only by the claims that follow.