US3122660A - High-voltage electrostatic generator - Google Patents

Description

Feb- 25 1964 G. M. GIANNINI ETAL HIGH-VOLTAGE ELECTROSTATIC GENERATOR 5 Sheets-Sheet 1 Filed Jan. l2, 1962 1N VEN TORS VOL 72765 007007' VOL 7%765 Feb. 25, 1964 G'. M. GIANNINI ETAL HIGH-VOLTAGE ELEcTRosTATIc GENERATOR 5 Sheets-Sheet 5 Filed Jan. 12, 1962 m TGE SOUQCE United States Patent O Filed Jan. 12, 1962, Ser. No. 165,778 claims. (el. 31o-s) This invention relates to a highvoltage electrostatic generator and method, and makes use of a high-velocity charge-carrying stream of liquid droplets.

An object ot the present invention is to provide a method and apparatus for generating electrical energy at high voltage, being characterized by extremely high charge densities in the stream of droplets.

A further object is to provide a highvoltage electrostatic generator Which is light in weight, and which is capable of creating highvoltages at currents much greater than are generated in prior-art apparatus.

A further object is to provide a method and apparatus for generating high voltages in an ethcient manner such that the iiow of liquid droplets may be metered precisely to achieve the desired voltage and current.

Another object is to provide a method and apparatus for generating a high voltage without creating the caking or crusting problems inherent in dust-type generators, without requiring the enormous belt sizes necessary for Van de Graait generators, and without the necessity for massive equipment adapted to move large volumes of gas.

An additional object is to provide an electrostatic generator the energy for which may be supplied solely by heat, no mechanical or moving parts being required, so that the generator is highly suitable and desirable for space vehicles.

Another object is to provide a voltage generator employing charge-carrying droplets which do work against the electrostatic eld by virtue of their own momentum, there being no necessity that ions be drawn along by large volumes of rapidly-flowing gas.

A further object is to provide a two-phase electrostatic generator incorporating a liquid which is in coherent liquid form in the return portion of the cycle.

An additional object is to provide a voltage generator incorporating means interposed in the stream of droplets to provide an electrical control eiiect.

These and other objects and advantages of the invention will be more fully set forth in the following specification and claims, considered in connection with the attached drawings to which they relate.

In the drawings:

FIGURE 1 is a schematic vertical central sectional View illustrating a iirst embodiment of a high-voltage electrostatic generator constructed in accordance with the present invention;

FIGURE 2 is a schematic vertical central sectional View illustrating a voltage generator constructed in accordance with a second embodiment of the invention; and

FIGURE 3 is a corresponding schematic section illustrating a third embodiment.

Referring first to the embodiment shown in FIGURE 1, the high-voltage electrostatic generator is illustrated to comprise an elongated tube or conduit 1t) formed of insulating material and preferably maintained in vertical relationship by a suitable support means, not shown. Sealingly connected at the upper end of conduit 1t) is a charge-collecting metal dome or sphere 11, such sphere being associated with a voltage output schematically represented at 12. At the lower end of conduit 1t? is provided a metal sump element 13. Such sump is suitably associated with the conduit 16 in sealing relationship, being grounded as indicated at 14.

3,122,660 Patented Feb. 25, 1964 Coaxially mounted in vertically spaced, superposed relationship in conduit 1() are a plurality of charge-collecting metal domes 16-21, inclusive. The domes 16-20 are tXedly connected to the interior wall of conduit 1t) by suitable means, not shown. The upper metal dome 21 is electrically connected to the charge-collecting sphere 11 by means of metal webs 22. It is pointed out that the coaxially-arranged domes have major diameters somewhat less than the inner diameter of conduit lt), so that an annular passage is formed radially-inwardly of the interior conduit wall to permit gravitational tiow of liquid to the sump 23 deiined by element 13.

An insulating tube or conduit 25 is connected to the sump 23 and is also connected, through a plurality of branch conduits, to metal nozzles 26 which are respectively mounted on and electrically connected to the pole portions ot' domes 16-20. The nozzles 26 are each directed upwardly so that the droplet sprays 27 emanating therefrom will impinge against the under surfaces ol' domes 17-21 and will not contact the interior wall of conduit 1d. Liquid is pumped to the nozzles by a suitable pump means indicated at 28.

It is a feature of the invention that the pumping action may also be eliected solely by heat, without rotating mechanical parts, by providing a suitable heat source, check valve, etc. Such use of heat is highly desirable when the electrostatic generator is employed in space.

A voltage source 31 is connected through a lead 32 to the lowermost dome 16 and thus to the metal nozzle 26 mounted thereon. Metal takes .33 are mounted on each of the domes 16-2ti and have their tine portions disposed in the paths of the droplet sprays 27. The rakes 33 and metal nozzles 26 cooperate with each other to effect charging of the droplets which emanate from the nozzles.

The sump 23 is tilled with a suitable insulating liquid,

such as oil or distilled water, adapted to be pumped by the pump means 2S to form the droplet sprays 27. It is emphasized that the sprays 27 are formed of small discrete liquid droplets, not vapor, the nozzles 2d being adapted to achieve this result in a manner known to the art.

It is pointed out that the liquid droplets in sprays 27 are projected upwardly through a gas (for example, air) which has a dilierent composition than that of the droplets (that is to say, is not the vapor of the liquid forming the droplets), Such shooting of droplets through a gas of a different nature produces important advantages, one of which is that the mass flow of liquid may be readily controlled in a manner achieving the desired voltage and current. t

Description of Method, Embodl'ment of FIGURE 1 The sump 23 is filled with a suitable insulating liquid such as a light oil or distilled water, and pump 28 is operated to` pump such liquid at very high pressure to all of the nozzles 26. The pressure may be thousands of pounds per square inch.

Voltage source `31 is applied to deliver a high voltage to dome 16 and its associated nozzle 26 and rake 33, such voltage being (for example) 10,000 volts.

The nozzle 26 on dome 16 converts the liquid into line droplets, not vapor, which droplets are eiected upwardly in a spray 27 until they impinge against the next dome 17. The veiocity of the droplet spray is, because of the great pressure, very high. The droplets are electrostatically charged due to combined action of nozzle 2o and rake 33. Because of such charging, the droplets spread apart due to mutual repulsion so that the spray 27 tends to fan out as indicated.

The droplets which impinge against the under surface of dome 17 deliver their charge to such dome, so that the voltage of dome 'i7 increases by a very substantial amount. The droplets then run down the under surface of dome ll7 and drip olf the lower edge thereof, after which they gravitate downwardly to the sump 23 in the form of the relatively large drops (not droplets) indicated at 36.

The charge on dome 17 is delivered by the associated nozzle 26 and rake 33 to the stream 27 of droplets emanating from the nozzle. It follows that the dome i3 its charged to a voltage much higher than that of dome 17. The drops on dome 18 combine to form large drops 36 which gravitate downwardly to the snmp 23 as in the case of the drops from dome 17. In like manner, the dome 19 is charged to a much higher voltage than dome 18, and domes Zt)l and 2l are charged to very much higher voltages. Thus, by the described voltage-multiplier action, the collecting sphere l1 is charged to a very high value, such as one million volts.

lt is emphasized that the droplets are very tine, so that there is an enormous amount of surface area capable of carrying electrostatic charge. It follows that the charge density of the sprays 2'7 is extremely high, so that the current generated by the apparatus may be a number of times greater than in prior-art apparatus.

Since the sprays 2.7 are composed of droplets and are not vapor, they are projected at high velocities and are not subject to drift. Furthermore, and very importantly, the charges move at the same velocity as the droplets instead of at a slower velocity as is the case in gas-type electrostatic generators. A further important advantage of the use of droplets is that the droplets combine into coherent masses (such as larger drops) which may be readily transported back to the sump by gravity or by an auxiliary pump.

The recirculation may, if desired, be effected outside the apparatus through a separate conduit leading to the sump 23. Such recirculation is to be contrasted with the use `of dust particles, for example, since such particles cluster together and may not be recirculated in a practical or eiiicient manner. ln constructions wherein the recirculation of liquid is forced and not gravitational, there is no necessity of maintaining the apparatus in vertical relationship.

it is emphasized that, in the present generator wherein the liquid droplets are shot through a gas (such as air) of a different nature than the liquid, the mass flow of liquid may be readily controlled by varying the operation of pump 23 or by auxiliary valve means (not shown). The droplets employed in the present apparatus are relatively insensitive to temperature gradients therein.

The described generator may lbe termed a two-phase apparatus since the liquid is in the form of very ne droplets while in sprays 27, but is in coherent masses while in the drops 36 and in the sump 223 and associated conduit 25. It is also pointed out that, in certain applications, the droplets may be frozen (ice) which melts to the liquid phase upon reaching the adjacent domes 7-2l. The use in the claims of the term two-phase is, however, to be interpreted as excluding liquid-vapor since vapor is relatively unsatisfactory in comparison to liquid droplets or frozen droplets. Stated otherwise, neither of the phases is a gaseous phase.

Embodz'ment of FIGURE 2 In the embodiment of FIGURE 2, an elongated insulating tube or conduit 4l is associated wtih a charge-coilecting metal sphere 42` at its upper end and wtih a metal A second insulating conduit 48, having a diameter substantially smaller than that of conduit 41, is mounted coaxially thereof and extends downwardly to the vicinity of sump element 43. Conduit 43 is connected to the lower end of small sphere 44, being registered with a large opening in such sphere. Suitable mounting means, not shown, are provided to maintain the conduit 43 fixedly in position.

A high-pressure pump 49' is provided adjacent sump element 43, having an intake 51 disposed in the body of liquid 52 in the sump. A nozzle 53 is connected to the outlet of pump 49 and is directed axially of the small conduit 48, so that a spray 54 of liquid droplets is passed upwardly to sphere 44. The pressure created by the pump 49 (which is only schematically represented) is extremely high, for example 20,0%() p.s.i. Because of the very high pressure, the droplets are ejected at enormous velocities tending to prevent them from separating excessively due to mutual repulsion. it is to be understood, however, that the diameters of conduits Il and 48 may be made much larger, in comparison to the lengths thereof, than is illustrated in the drawing.

A suitable voltage source 56 is connected to the metal nozzle 53, so that the particles emanating therefrom will be charged. T he charge-collecting large sphere 42 is illustrated as being associated wtih a voltage output 57. The sump element 43 is grounded at 58.

In performing the method with the embodiment of FIGURE 2, the oil, distilled water or other liquid is converted into droplet form by the nozzle 53' and is directed upwardly at high velocity into the small sphere `d4. Since the droplets are charged by the voltage source 56, a charge builds up on the small sphere 44. This charge is transmitted through the conductive webs 47 to the chargecollecting sphere 42 and thus to voltage output 57.

The droplets pass through openings 46 and engage the walls of sphere 42, after which they gravitate downwardly through the annulus 61 (between conduits 41 and 4S) and back into the sump 43. The system is thus two phase, in the sense described relative to the previous embodiment, that is to say between liquid in droplet form and liquid in large drops or coherent masses.

Embodz'ment of FIGURE 3 Referring to FGURE 3, there is schematically illustrated an electrostatic generator which is not of the recirculating type, although it is to be understood that means may be employed to recirculate liquid back to the source thereof, either through the apparatus or through an outside conduit.

An insulating tube or conduit 66 is connected at its upper end to a metal sphere 67, around a large opening therein. Such sphere has additional openings 68 adapted to discharge droplets to the ambient atmosphere or to a suitable recirculating means. A charge-collecting rake 6% is disposed in and connected to the sphere 67, serving to deliver' charge thereto and thus to a suitable voltage output which is indicated at 71.

Mounted at the lower end of the conduit or tube 66 is a metal pressure element or bomb 72 containing a suitahle liquid (such as an insulating oil or distilled water) under very high pressure. A nozzle 73 is mounted at the outlet of element 72 and is directed upwardly coaxially of tube 66.

A rake 74, which is connected toV a suitable voltage source 75, is disposed in the spray 76 emanating from nozzle 73. The voltage source is also connected to one end of the winding 77 of a potentiometer 78, the other end of the winding being connected to the metal clement 72 which is grounded as indicated at 79. The sliding tap Sti of the potentiometer 73 is electrically connected to a grid or control element 81 disposed in tube d6 in the path of the spray 76. Grid or control 81 may comprise a mesh of ne, electrically-conductive wires, being highly permeable to the spray 76.

aisance ln performing the method in accordance with the embodiment of FGURE 3, the voltage source '75' is employed to impose a voltage on ralre 7d and thus on the stream i6 of liquid droplets. The droplets ol oil or other suitable insulating duid are ejected from nozzle '73 due to the enormous pressure present in the pressure element or bomb 72. The spray passes upwardly to the sphere 67 to create thereon a very high voltage, collection of the charge being aided by the rake 69.

It is a feature of the invention that the voltage of the collecting sphere 67 may be regulated not only by varying the ilow of droplets but also by adjusting the tap Sti of potentiometer 7&3 to give control element Si a desired voltage. Stated otherwise, the charge on grid 81, as determined by the position of tap or slider Si), has a bearing on the charge delivered by the spray 76 to rake 69 and sphere 67. A very precise control of the voltage on sphere 67 may thus be achieved.

Additional Factors and Structure Relating t0 All Embodiments An additional important feature or t'ne invention is that the method ymay be performed in a quasi or partial vacuum, in order to achieve various advantages including higher velocity of movement of the charge droplets, and better insulation against undesired loss of charge by the droplets and by the domes )t6-21. To accomplish such results, a liquid (such as a suitable oil) is employed which has a low vapor pressure. The conduit it) (ElGURE l) is then evacuated, as by the means schematically represented at V. It is to be understood that evacuation means may also be employed with the embodiments oi FGURES 2 and 3.

When the apparatus is employed in outer space the evacuation means may, of course, be omitted. However, when the apparatus is disposed in a gravitationless field it is desirable to generate artificially a gravitational gradient causing the drops 36 (FIGURE l) to return to sump 23.

The gravitational gradient may be created by rotating the entire apparatus around the center point C (FGURE l), for example by means of a suitable motor M and connected shaft S. Similar apparatus may be incorporated in the embodiments of FIGURES 2 and 3.

Various embodiments of the present invention, in addition to what has been illustrated and described in detail, may be employed without departing from the scope of the accompanying claims.

We claim:

1. A high-voltage electrostatic generator, comprising an insulating conduit, an insulating liquid, charge-collector means provided at one end portion of said conduit, a series of spaced spray-collecting metal elements disposed along said conduit, nozzle means associated with the respective spray-collecting elements and directed toward said chargecollector means, the nozzle means associated with each of said sprayecollecting elements being adapted to transmit therefrom to the adjacent element a spray of discrete droplets of said liquid, said droplets being charged by the spray-collecting element associated with such nozzle means, memis to charge to an initial Voltage the droplets emanating from a nozzle means remote from said chargecollector means, and pressure means to force droplet sprays at high velocities out each of said nozzle means.

2. The invention as claimed in claim l, in which each of said spray-collecting elements is a metal dome, and in which said pressure means to force sprays out said nozzle means includes an insulating conduit having a plurality of branches communicating with the respective nozzles.

3. The invention as claimed in claim 2, in which the major diameters or said domes are smaller than the internal diameter of said conduit whereby space is pro vided between said domes and conduit for recirculation to the inlet of said pressure means of coherent masses of liquid.

4. The invention as claimed in claim l, in which means are provided to maintain the space within said conduit in substantially evacuated condition.

5. A high-voltage electrostatic generator, which comprises an insulating liquid, charge-coll ctor means, a substantial number of electrically-conductive spray-collecting elements, said spray-collecting elements being disposed in a row and in electrically-insulated relationship relative to said charge-collector means and to each other, the spraycoilecting element at one end o said row being relatively adiacent said charge-collector means, nozzle means associated with each of said spray-collecting elements and directed toward said charge-collector means, the nozzle means associated with each of said spray-collecting elements other than said end element being ad( pted to transmit to the adjacent element a spray of discrete droplets of said liquid, said droplets being charged to the voltage of the spray-collecting element associated with such nozzle means, the nozzle means associated with said end element being adapted to transmit therefrom to said charge-collector means a spray of discrete droplets of said liquid, said droplets being charged by said end element to the voltage thereof, means to charge to an initial voltage the droplets emanating from a nozzle means remote from said end element, pressure means to force droplet sprays of said liquid at high velocities out each of said nozzle means, and electrically-insulating means to recirculate liquid from said charge-collector means to said nozzle means.

References Cited in the le of this patent UNITED STATES PATENTS 2,078,760 Hanscll Apr. 27, 1937 2,308,884 Lindenblad Ian. 19, 1943 FOREIGN PATENTS 1,108,105 France Aug. 24, 1955 OTHER REFERENCES Publication: Project Satellite by Gatland, published by Wingate, London, England; pages 123, 124,

Claims (1)

1. A HIGH-VOLTAGE ELECTROSTATIC GENERATOR, COMPRISING AN INSULATING CONDUIT, AN INSULATING LIQUID, CHARGE-COLLECTOR MEANS PROVIDED AT ONE END PORTION OF SAID CONDUIT, A SERIES OF SPACED SPRAY-COLLECTING METAL ELEMENTS DISPOSED ALONG SAID CONDUIT, NOZZLE MEANS ASSOCIATED WITH THE RESPECTIVE SPRAY-COLLECTING ELEMENTS AND DIRECTED TOWARD SAID CHARGECOLLECTOR MEANS, THE NOZZLE MEANS ASSOCIATED WITH EACH OF SAID SPRAY-COLLECTING ELEMENTS BEING ADAPTED TO TRANSMIT THEREFROM TO THE ADJACENT ELEMENT A SPRAY OF DISCRETE DROPLETS OF SAID LIQUID, SAID DROPLETS BEING CHARGED BY

Images