Abstract:
An electrohydrodynamic conduction liquid pumping system includes a vessel configured to contain a liquid or a liquid/vapor therein. This vessel can be of a elongate conduit configuration, an elongate channel configuration or a liquid enclosure configuration. At least a single pair of electrodes are disposed in a spaced apart relation to each other on the vessel and configured to be oriented in the liquid. A power supply is coupled to the electrodes and operable to generate electric fields in between the pair of electrodes, the electric forces inducing a net liquid movement relative to the vessel. Various electrode designs are embraced within the concept of this invention.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is a national stage application under 35 USC 371 of PCT/US03/18930, filed Jun. 16, 2003 which claims the benefit of U.S. Provisional Application Ser. No. 60/390,848, filed Jun. 21, 2002. 

   STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   The U.S. government has a paid-up license in this invention and the right in limited circumstances to require the patent owner to license others on reasonable terms as provided for by the terms of Contract No. 32525-54750 awarded by NASA—Headquarters—Microgravity Fluid Physics Program. 

   BACKGROUND OF THE INVENTION 
   The subject matter of this disclosure is related to the disclosure in co-pending application Ser. No. PCT/US01/22803, filed Jul. 18, 2001, now U.S. Pat. No. 6,932,580, which is incorporated herein by reference. With the discovery set forth therein, there became an ever increasing demand for improved conduction pumping characteristics. Various new electrode configurations were investigated by me and found to be successful and are the subject matter of this disclosure. 
   SUMMARY OF THE INVENTION 
   An electrohydrodynamic conduction liquid pumping system includes a vessel configured to contain a liquid or a liquid/vapor therein. This vessel can be of a elongate conduit configuration, an elongate channel configuration or a liquid enclosure configuration. At least a single pair of electrodes are disposed in a spaced apart relation to each other on the vessel and configured to be oriented in the liquid. A power supply is coupled to the electrodes and operable to generate electric fields in between the pair of electrodes, the electric forces inducing a net liquid movement relative to the vessel. Various electrode designs are embraced within the concept of this invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The objects and purposes of this invention will be apparent to persons acquainted with apparatus of this general type upon reading the following specification and inspecting the accompanying drawings, in which: 
       FIG. 1  is a schematic illustration of a first embodiment of a conduction pumping mechanism consisting of a high voltage ring electrode and a ring electrode ground oriented on a conduit configured to convey a liquid therein; 
       FIG. 2  is a schematic illustration of a second embodiment of a conduction pumping mechanism; 
       FIG. 3  is a schematic illustration of a third embodiment of a conduction pumping mechanism which includes two radially spaced rings configured for high voltage in conjunction with a grounded ring electrode; 
       FIG. 4  is a schematic illustration of a fourth embodiment of a conduction pumping mechanism having three radially spaced ring electrodes configured for high voltage application in conjunction with a grounded ring electrode; 
       FIG. 5  is a schematic illustration of a fifth embodiment of a conduction pumping mechanism utilizing spaced tubes suspended in a conduit and configured for high voltage application in conjunction with a grounded ring electrode; 
       FIG. 6  is a schematic illustration of a sixth embodiment of a conduction pumping mechanism having a plate with multiple holes provided therethrough and configured for high voltage application in conjunction with a grounded ring electrode; 
       FIG. 7  is a longitudinal cross sectional view of a conduction pumping mechanism corresponding in concept to  FIG. 6 ; 
       FIG. 8  is a sectional view taken along the line VIII-VIII of  FIG. 7 ; 
       FIG. 9  is a longitudinal sectional view corresponding to  FIG. 6 ; 
       FIG. 10  is a sectional view taken along the line X-X of  FIG. 9 ; 
       FIG. 11  is a schematic illustration of a seventh embodiment of a conduction pumping mechanism wherein concentric annular rings are configured for high voltage are suspended within the conduit and in conjunction with a grounded ring electrode; 
       FIG. 12  is a schematic illustration of an eighth embodiment of a conduction pumping mechanism similar to  FIG. 1  wherein the high voltage electrode is of a differing configuration; 
       FIG. 13  is a schematic illustration of a ninth embodiment of a conduction pumping mechanism similar in concept to  FIGS. 6-10  wherein the high voltage electrode is a porous plate or disc through which all of the liquid must pass; 
       FIG. 14  is a schematic illustration of a tenth embodiment of a conduction pumping mechanism wherein the plate or disc is porous and is smaller in cross section than the cross section of the conduit; 
       FIG. 15  is a schematic illustration of an eleventh embodiment of a conduction pumping mechanism similar to  FIG. 13  wherein an annular ring is porous; 
       FIGS. 16-19  are respective cross sectional views illustrating differing porosities of the high voltage electrode corresponding to  FIG. 13 ; 
       FIG. 20  is a schematic illustration of a conduction pumping thermal energy transfer system wherein liquid is present on the outer surface of a heat transfer element; 
       FIG. 21  is a plan view of a high voltage electrode utilized in  FIG. 20 ; 
       FIG. 22  is a schematic illustration of a conduction pumping thermal energy transfer system wherein liquid is present on the inside surface of the conduit and the electrode of  FIG. 21  is oriented inside the conduit; 
       FIGS. 23 to 25  are enlarged schematic illustrations of alternate electrode configurations for the embodiments of  FIGS. 20 and 22 ; 
       FIG. 26  is a schematic illustration of a conduction pumping thermal energy transfer system in a channel environment; 
       FIG. 27  is a schematic illustration similar to  FIG. 23  except that the high voltage electrode is in the form of parallel plates; 
       FIG. 28  is a schematic illustration similar to  FIG. 23  except that the high voltage electrode is of a differing configuration; 
       FIG. 29  is a schematic illustration of a vessel housing liquid therein and in which is provided a conduction pumping mechanism; 
       FIG. 30  is a schematic illustration of a vessel partially filled with liquid and in which is provided a conduction pumping mechanism; and 
       FIG. 31  is a schematic illustration of a manifold having a single liquid input and plural liquid outputs with one or more conduction pumping mechanisms oriented in each of the outlets in order to balance the liquid flow through each of the outlets. 
   

   DETAILED DESCRIPTION 
   The concept of conduction pumping is set forth in detail in pending application Serial No. PCT/US01/22803, filed Jul. 18, 2001. Thus, further discussion concerning the concept is believed unnecessary, especially since the disclosure in that application is incorporated herein by reference. 
   Referring to  FIG. 1 , there is provided an elongate conduit C configured for transporting a liquid therethrough. A ground electrode  10  is provided on the conduit with the radially inner surface of the electrode  10  being flush with the inside surface  11  of the conduit C. A ring high voltage electrode  12  is mounted to the inside surface  11  of the conduit C with the cross section of the ring extending from the inside wall of the conduit radially inwardly a finite distance.  FIG. 2  illustrates a conduction pumping mechanism similar to  FIG. 1  except that the high voltage electrode  13  is configured so that the inside surface  14  thereof is flush with the inside surface  11  of the conduit C. It is to be understood that the term “flush” as used herein and elsewhere is to embrace locations wherein the electrodes are spaced radially inwardly and outwardly from the surface  11  a small distance. 
     FIG. 3  illustrates a conduction pumping mechanism similar to  FIG. 1  except that an additional ring  16  is concentrically oriented inside the ring  12  with both rings being connected to a high voltage source V.  FIG. 4  is similar to  FIG. 3  except that there is an additional ring  17  concentrically disposed relative to the two other rings  12  and  16 . In the embodiment of  FIGS. 3 and 4 , the centrally disposed rings  16  and  17  are suspended by the electrical connection  18  that serves to connect each of the rings to the high voltage source V. 
     FIG. 5  is a schematic illustration of a conduction pumping mechanism inside a conduit C and with a ground ring electrode  10  identical to that in the preceding  FIGS. 1-4 . A plurality of hollow tubes  19  are suspended inside the conduit C by connection to the electrical conductor  18  that connects the aforesaid hollow tubes  19  to a high voltage source V. In this particular embodiment, the central axes of the hollow tubes  19  are parallel to each other and parallel to the longitudinal axis of the elongate conduit  19 . In this particular embodiment, and as depicted by the arrows of the total net flow of liquid occurring across the cross section of the conduit, only some of the liquid will pass through the interior of the hollow tubes  19 . 
     FIG. 6  schematically illustrates a conduction pumping mechanism utilizing a grounded electrode  10  identical to the grounded electrodes discussed above with respect to  FIGS. 1-5 . A flat plate or disc  21  having a plurality of holes  22  extending therethrough and on axes that are parallel to each other and to the longitudinal axis of the elongate conduit C is provided. The flat plate  21  is mounted to the inside surface  11  of the conduit C. The flat plate  21  is connected by an electrical connection  18  to a high voltage source V. 
     FIGS. 7 and 8  illustrate a configuration wherein the diameter of the holes  22  in the flat plate  21  have a diameter of 1.14 mm.  FIGS. 7 and 8  furthermore illustrate the structure of the conduit for facilitating an orienting of multiple pairs of electrodes along the length of the conduit C.  FIGS. 9 and 10 , on the other hand, are similar to  FIGS. 7 and 8  and illustrate that the diameter of the holes  22  in the flat plate  21  are 1.59 mm.  FIGS. 7-10  also illustrate that the flat plate  21  can be oriented inside the conduit C by suspending it from the electrical conductor  18  facilitating connection thereof to the high voltage source V. 
     FIG. 11  schematically illustrates a conduction pumping mechanism similar to  FIG. 3  except that the two annular rings which are concentric with each other and with the longitudinal axis of the conduit C and are suspended in the interior of the conduit by the electrical connection  18  which facilitates connection of the rings  23  and  24  to the high voltage source V. While two rings  23  and  24  are illustrated, more rings can be provided where desirable. In this particular embodiment, and as depicted by the arrows, of the total net flow of liquid occurring across the cross section of the conduit, only some of the liquid will pass through the interior of the rings  23  and  24 . The grounded ring electrode  10  is identical to the configurations shown in the preceding figures. 
     FIG. 12  is similar to  FIG. 1  except that the electrode  26 , corresponding to the electrode  12  in  FIG. 1 , is of a rounded configuration to form a rounded protuberance extending radially inwardly from the interior wall  11  of the conduit C. The grounded ring electrode  10  is identical to the configuration illustrated in  FIG. 1 . The electrical connection  18  facilitates connection of the electrode  26  to a high voltage source V. 
     FIG. 13  illustrates a flat plate or disc  27  which is porous and which is connected by the electrical connection  18  to the high voltage source V. The grounded ring electrode  10  is identical to the grounded ring electrodes discussed above. 
     FIG. 14  schematically illustrates a conductive pumping mechanism wherein a flat plate or disc  28  is porous and is suspended in the conduit C by the electrical connection  18  in generally the central region of the cross section of the conduit. The grounded ring electrode  10  is identical to the electrodes shown and described above. The annular porous flat plate or disc  28 A as shown in  FIG. 15  is supported by the conduit C. 
     FIGS. 16-19  disclose embodiments corresponding to  FIG. 13 .  FIGS. 16 and 17  illustrate a porous plate or disc wherein the porosity is 0.2 microns in  FIGS. 16 and 17  and 40.0 microns in  FIGS. 18 and 19 . In addition,  FIGS. 16-19  illustrate the format for the conduit and the electrodes  27  and  10  so that a multiple set of pairs can be oriented one after the other along the length of the conduit C to facilitate conduction pumping of the liquid being transported through the conduit C and through the porous electrode  27 . 
     FIG. 20  illustrates an electrohydrodynamic conduction pumping thermal energy transfer system which utilizes a conduit having inside surface  41  and exterior surface  42 . A grounded ring electrode  43  is provided on the exterior surface of the conduit and is axially spaced from an annular high voltage ring electrode plate  44  having a finite radial width as illustrated in  FIG. 21 . The ring electrode  44  has a plurality of side-by-side holes  46  extending therethrough. In this particular embodiment, the holes are cylindrical in nature although they could be of other configurations as well. The high voltage electrode  44  is connected through an electrical connection  47  to a high voltage source V. The high voltage electrode  44  is oriented axially spaced from the grounded ring electrode  43  in a manner similar to the configurations discussed above. In this particular embodiment, a cooling medium is transported through the interior of the conduit C so that, in a two phase liquid environment, a liquid condensate will form on the exterior surface of the conduit C. The electrodes  43  and  44  are configured to be oriented in the liquid condensate and when electrical energy is applied to the electrodes, the liquid condensate and a limited amount of the adjacent vapor phase will be conductively pumped longitudinally of the conduit simultaneously while new condensation is forming on the exterior surface of the conduit C. 
     FIG. 20  could also be utilized in an environment where a heating medium is pumped through the interior of the conduit C to effect an evaporation of liquid interfacing with the exterior surface of the conduit C. In this instance, electrical energy applied to the electrodes  43  and  44  would effect movement of the liquid to facilitate a more efficient evaporative process. 
     FIG. 22  is similar to  FIG. 20  except that liquid is present on the inside surface  41  of the conduit  42 . The ring electrode  43 A and the ring electrode  44 A are provided on the inside surface of the conduit C and are configured to be oriented within the liquid layer. The plural holes through the electrode  46  are also within the liquid, as is the case in the preceding embodiment so that liquid will pass through the holes  46  as a result of the conduction pumping phenomena.  FIG. 22  is configured to be utilized in an environment where the liquid is a condensate or is a liquid to be evaporated in a manner similar to that described above for  FIG. 20 . 
   It is to be understood that in regions of the conduit whereat heat transfer is not taking place, arranging series arrays of electrode pairs in any liquid present thereat will, when appropriately energized, facilitate the movement thereof to a desired destination. 
     FIGS. 23 to 25  illustrate different electrode designs for the embodiments of  FIGS. 20 and 22 .  FIG. 23  schematically illustrates an electrode design  43 B,  44 B similar to  FIG. 1 .  FIG. 24  schematically illustrates a grounded electrode  43 B similar to  FIG. 23  while the high voltage electrode  44 C is in the form of rings concentric with the axis of the conduit C.  FIG. 25  schematically illustrates an electrode design  44 D,  44 B similar to  FIG. 12 . 
   While in the preceding discussion the conduits and electrodes have been depicted as circular in cross section, it is to be understood that all non-circular cross sections are embraced within the scope of this disclosure. That is, the conduits and electrodes can have an elliptical cross section and the like or a polygonal cross section. 
     FIG. 26  schematically illustrates a conduction pumping mechanism  50  used in association with a liquid guiding channel  51 . In this embodiment, the grounded electrode  52  is a plate oriented flush with the bottom surface  53  of the channel  51 . The high voltage electrode  54  is connected by an electrical connection  56  to a high voltage source V. In this particular embodiment, the high voltage electrode protrudes into the interior of the channel and both electrodes  52  and  54  are configured to be oriented within the liquid. 
     FIG. 27  is similar to  FIG. 26  except that the high voltage electrode is a pair of parallel plates  57  extending parallel to the longitudinal axis of the channel  51  and to the bottom surface  53  of the channel  51 . 
     FIG. 28  is similar to  FIG. 26  except that the high voltage electrode  58  has a rounded surface configuration as compared to the more rectangular version illustrated in  FIG. 26 . 
     FIG. 29  schematically illustrates a vessel  60  housing a liquid therein with a grounded ring electrode  61  oriented so that the interior surface thereof is flush with the interior surface  62  of the vessel  60 . An elongate bar  63  is oriented inside the vessel  60  and is configured to serve as the high voltage electrode connected through an electrical connection  64  to the high voltage source V. In this particular embodiment, and since the vessel is closed, electrical energy applied to the electrodes  61  and  63  will effect a circulatory motion of the liquid in directions indicated by the arrows  66 - 69 . This configuration will facilitate in circulatory motion of liquids in environments where circulation is required. 
     FIG. 30  schematically illustrates a vessel  60 A partially filled with liquid  65 . Electrical energy applied to the electrodes  61 A and  63 A will effect a circulatory motion of the liquid in directions indicated by the arrows  66 - 67 . 
     FIG. 31  schematically illustrates a manifold  70  having a liquid inlet port  71  and plural liquid outlet ports  72 . The liquid outlet ports  72  are in the form of conduits similar to the conduits described above and each conduit has a series of electrodes therein. The volume of liquid passing through each conduit  72  is monitored by a detector  73  and the voltage of the power supply is determined by a signal transmitted from the liquid flow detector  73  through the control lines  74  to the power supply to regulate the amount of high voltage V applied to the high voltage electrodes. The conduction pumping mechanisms in each conduit will therefore serve to effect an equalized flow of single phase liquid or two phase liquid/vapor through each of the conduits. It is additionally possible for the liquid flow detection device  73  to separately monitor the liquid flow through each conduit so that a corresponding electrical signal will be sent through a corresponding control line  74  to multiple and separate power supplies so that the volume of liquid being conduction pumped through each conduit will be precisely regulated. 
   Embraced within this disclosure is the feature of vapor depositing the electrodes onto the surface of the conduit or channel. Also embraced within this disclosure is the use of the conduction pumping mechanism to facilitate pumping of liquid and any bubbles therein. 
   While the electrodes have been illustrated in the drawings as having sharp corners, edges and the like, it is to be understood that the corners and edges of all electrodes are radiused. The magnitude of the radius is a function of the magnitude of the voltage and the magnitude of the electric fields. The rounded corners and edges will prevent ion injection during conduction pumping. 
   A grounded electrode has been specifically referenced in each of the above embodiments. It is to be understood that the phrases “high voltage electrode” and “high voltage source” as used herein and throughout merely indicate that there is to exist a sufficient potential difference between the electrodes to generate electric fields therebetween. 
   Although particular preferred embodiments of the invention have been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.