US3225252A - Electrohydraulic system and working fluids therefor - Google Patents

Electrohydraulic system and working fluids therefor Download PDF

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Publication number
US3225252A
US3225252A US323363A US32336363A US3225252A US 3225252 A US3225252 A US 3225252A US 323363 A US323363 A US 323363A US 32336363 A US32336363 A US 32336363A US 3225252 A US3225252 A US 3225252A
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US
United States
Prior art keywords
energy
working fluid
discharge
electrohydraulic
electrical
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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US323363A
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English (en)
Inventor
Edward C Schrom
Allen Merton
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General Electric Co
Original Assignee
General Electric Co
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Filing date
Publication date
Priority to DENDAT1252449D priority Critical patent/DE1252449B/de
Application filed by General Electric Co filed Critical General Electric Co
Priority to US323363A priority patent/US3225252A/en
Priority to GB43846/64A priority patent/GB1073739A/en
Priority to NL6413035A priority patent/NL6413035A/xx
Priority to SE13634/64A priority patent/SE312879B/xx
Application granted granted Critical
Publication of US3225252A publication Critical patent/US3225252A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K15/00—Acoustics not otherwise provided for
    • G10K15/04—Sound-producing devices
    • G10K15/06—Sound-producing devices using electric discharge
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D26/00—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces
    • B21D26/02—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces by applying fluid pressure
    • B21D26/06—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces by applying fluid pressure by shock waves
    • B21D26/12—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces by applying fluid pressure by shock waves initiated by spark discharge
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
    • H01T2/00—Spark gaps comprising auxiliary triggering means
    • H01T2/02—Spark gaps comprising auxiliary triggering means comprising a trigger electrode or an auxiliary spark gap
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49805—Shaping by direct application of fluent pressure
    • Y10T29/49806—Explosively shaping

Definitions

  • This invention relates generally to an electrohydraulic spark discharge system having an improved working medium for greater operating efliciency. More particularly, the present invention relates to an improved electrohydraulic system with a modified dielectric liquid operatively associated with the spark gap to reduce energy loss during the discharge cycle.
  • Electrohydraulic systems convert electrical energy to a steep pressure wave in a liquid medium for useful work.
  • the energy released takes place by spark discharge across a suitable gap at sufliciently high rates to cause ionization of liquid in the gap.
  • the working force represented by the pressure wave is of suflicient magnitude to form metal members in communication with the working fluid for such useful operations as forging, hole drilling, bending, and the like.
  • Utilization of the electrohydraulic working force has been suggested for such other diversified applications as rock crushing, pile driving, material compaction, and vibratory devices
  • Past systems often employ conventional dielectric liquids such as water or hydrocarbon oil for the energy conversion medium.
  • ionic liquids such as aqueous salt solution were found useful since the discharge phenomenon depends primarily upon ionization of the working fluid rather than ionic conductance therethrough.
  • Faster ionization favorably influences rate of energy release and traditionally the working fluid has been a single phase liquid with uniform vaporization characteristics. It has been reported that discharge occurs more rapidly with consequent faster rate of pressure buildup in salt water.
  • a soluble ionic compound in the working fluid lowers conversion efiiciency of electrical energy to the pressure Wave.
  • An electrohydraulic working fluid providing faster discharge for greater pressure generation in the medium without attendant lower energy conversion would be of great benefit.
  • Another important object of the invention is to provide a working fluid permitting extension of the electrohydraulic spark gap at given energy levels for greater pressure wave generation upon discharge and less erosion of the gap construction
  • FIGURE 1 is a schematic electrical diagram illustrating one electrohydraulic system of the invention.
  • FIGURE 2 represents a different electrohydraulic system of the invention.
  • the improved electrohydraulic spark discharge systems of the invention comprise a source of high voltage electrical energy, capacitor storage means for the electrical energy, means for discharging the stored elec- ,trical energy in pulse form, and means for conducting the energy pulse to a spark gap :operatively associated with a working fluid containing particulate conducting 3,225,252 Patented Dec. 21, 1965 solids.
  • the improved working fluid comprises a multiphase composition having a continuous phase of dielectric liquid and a dispersed phase of conductive particulates which are substantially insoluble in the liquid.
  • the term dispersed as used to described the working fluid signifies ability to be dispersed in the continuous phase by spark discharge as well as the more conventional connotation of a suspension which does not readily settle out of the liquid.
  • the thickness of the insulation barrier to current flow is eifectively reduced and the originally applied potential achieves conduction through the entire medium.
  • the time interval for dielectric breakdown in solid insulation is often shortened by the nature of discontinuities in the medium. While electrohydraulic energy conversion diflers in most other aspects from the dielectric breakdown phenomenon above described, the similarities pointed out are believed helpful to better understand the functions performed by conductive particulates in the working fluid.
  • conductive particles may be dispersed in the Working fluid by conventional tech nique to form a stable suspension.
  • Emulsifiers, dispersing agents, or selection of a dielectric liquid with similar density to the particulate material provide known means 'for suspending solids in a liquid environment. It is also contemplated to physically circulate the Working fluid during spark discharge as will be subsequently described in greater detail hereinafter in the specification. Additionally, upon spark discharge, particulates which may be settled in the liquid receive sufficient impetus to produce the desired dispersion.
  • Preferred particulates for incorporation in the dielectric liquid are metal compositions including metal elements, alloys, and metallic compounds exhibiting good electrical conductivity, substantial insolubility in the liquid, and reasonably resistant to mechanical disintegration from the shock wave generated by spark discharge. While energy conservation is achieved at even minute concentrations of particulates in the working fluid, it has been found desirable to restrict the upper concentration limit below that resulting in decreased volume resistivity of the mixture below around 1000 ohm-centimeters. Lower volume resistivity produces other power losses during spark discharge so that the dielectric liquid of the working fluid must exhibit the mentioned resistivity characteristics.
  • One form of undesirable energy dissipation with low resistance working fluids is spark reignition during a single pulse from the associated high energy electrical circuit. More particularly, in electrohydraulic systems, the first cycle of current across the gap is of such higher magnitude than all successive cycles that little or no useful work is accomplished during the latter discharge. Spark reignition thereby dissipates energy otherwise available during the work-producing discharge.
  • FIGURE 1 there is depicted schematically an electrohydraulic system employing the above described working fluid in association with a low impedance electrical circuit for efficient energy conversion.
  • Electrohydraulic system 1 comprises generally a capacitor discharge circuit 2 connected to chamber means 3 housing the work gap element 4 and the working fluid 5.
  • Capacitor discharge circuit 2 comprises a source of high voltage electrical energy 6, capacitor storage means 7 for the electrical energy, electrical discharge means 8 for releasing the stored electrical energy in pulse form, and conductor means 9 for transmitting the energy pulse received to the spark gap.
  • Capacitor discharge circuit 2 comprises a source of high voltage electrical energy 6, capacitor storage means 7 for the electrical energy, electrical discharge means 8 for releasing the stored electrical energy in pulse form, and conductor means 9 for transmitting the energy pulse received to the spark gap.
  • Detailed description of the particular discharge circuit chosen for illustration appears in the copending application, Serial No.
  • capacitor element 10 is charged to the desired voltage level from an adjustable high voltage power supply 11 whereupon switch element 12 may be opened to disconnect the power supply from the capacitor as a safety precaution preventing stored energy from being returned to the power supply.
  • the stored energy may be discharged through a three-electrode tube rectifier which provides the switch function in discharge means 8.
  • the energy pulse received from the discharge means may thereafter be transmitted through a shielded coaxial power cable serving as low impedance conductor means 9 for carrying the energy to the spark gap.
  • the complete discharge path of the circuit for spark discharge comprises the serially connected capacitor, three-electrode tube, power cable, and spark gap with electrical return from the spark gap taking place through ground connection 13 in the circuit.
  • Capacitor element 10 of the circuit is shown connected to current limiting resistor 14 for relief of the residual capacitor charge after discharge through the rectifier element 8 upon closure of switch 15.
  • the time of residual charge dissipation may be shortened by closing second switch 16 in a particular time sequence after closure of switch 15.
  • the mentioned switch elements are normally operated only upon termination of the final discharge cycle.
  • Spark gap element 4 of the circuit is located in the working fluid. As shown, the working fluid comprises a continuous phase of dielectric liquid 17 having uniformly dispersed therein a quantity of discrete individual metal particles 18.
  • FIGURE 2 there is depicted schematically an electrode member 20 having associated chamber means 21 in which spark discharge is generated.
  • a capacitor discharge circuit of the same general configuration described for FIGURE 1 may again be employed to provide successive high energy electrical pulses to the electrode.
  • the electrode element of the embodiment performs the spark gap function of the preceding embodiment being connected in the electrical circuit as previously described.
  • Different conductor means 22 are employed for connection of the electrode member, iowever, illustrating equivalent construction of a low impedance circuit to provide efficient energy conversion.
  • conductor elements 22 leading from the electrode and all conductors in the electrical circuit may comprise a parallel bus bar network interconnecting the circuit components.
  • Electrode 2 comprises a longitudinally extending body 23 having a working tip portion 24 at one end of the member and electrical termination portion 25 at its opposite end.
  • Body portion 23 consists of a solid electrically conducting rod element 26 at the center axis of the member and extending its entire length, hollow conducting sheath 27 of larger internal diameter than the rod and disposed coaxially to define a continuous annular space with the rod, and dielectric spacer means 28 occupying the annular space and bonding the sheath to the rod to form a unitary solid construction for the length of the electrode.
  • Working tip portion 24 is formed by adjacent ends of the conducting elements interconnected with bonded dielectric and may conveniently have the conical configuration shown in order to regulate the shape and/ or direction of the shock wave formed thereat.
  • Terminal portion 25 of the electrode consists of electrical connector means 29 atfixed directly to the outer surface of the sheath having an associated dielectric bushing 30 to provide electrical separation between said connector means and adjacent end portion 31 of the center conducting rod. To insure electrical separation at the relatively high operating voltages employed, it will be advisable to maintain longer path lengths across the bushing than the annular distance separating the conducting elements.
  • Chamber 21 in which the electrohydraulic work force is generated, has means associated therewith for circulating the working fluid during spark discharge.
  • the circulation means 32 may consist of a liquid pump 33 with inlet and discharge sides connected directly to the chamber by conduit means 34 for sustained flow of the working fluid past the electrode. Liquid flow rate may thereby be established in the chamber sufficient to keep the particulate matter of the working fluid in dynamic suspension.
  • An electrohydraulic spark discharge system which comprises a source of high voltage electrical energy, capacitor storage means for the electrical energy, electrical discharge means for releasing the stored electrical energy in pulse form, and conductor means for transmitting the energy pulse to a spark gap immersed in a working fluid, said working fluid comprising a multiphase composition having a continuous phase of dielectric liquid and a dispersed phase of electrically conductive substantially insoluble particulates.
  • An electrohydraulic spark discharge system which comprises a transformer source of high voltage electrical energy, capacitor storage means for the electrical energy, rectifier means for discharging the stored electrical energy in pulse form, and conductor means for transmitting the energy pulse to a spark gap immersed in a working fluid, said working fluid comprising a multiphase composition having a continuous phase of dielectric liquid and a dispersed phase of electrically conductive substantially insoluble particulates.
  • An electrohydraulic spark discharge system which comprises a low impedance electric-a1 circuit defined by series connection of a transformer source of high voltage electrical energy, capacitor storage means for the electrical energy, electronic rectifier means for discharging the stored electrical energy in pulse form, and conductor means for transmitting the energy pulse to a spark discharge electrode immersed in a working fluid, said working fluid comprising a multiphase composition having a continuous phase of dielectric liquid and a dispersed phase of electrically conductive substantially insoluble particulates.
  • An electrohydraulic spark discharge system which comprises a low impedance electrical circuit defined by series connection of a transformer source of high voltage electrical energy, capacitor storage means for the electrical energy, electronic rectifier means for discharging the stored electrical energy in pulse form, and conductor means for transmitting the energy pulse to a spark discharge electrode having common electrical ground means with the capacitor storage means and immersed in a working fluid, said working fluid comprising a multiphase composition having a continuous phase of dielectric liquid and a dispersed phase of electrically conductive substantially insoluble particulates.
  • An electrohydraulic spark discharge system which comprises a low impedance electrical circuit defined by series connection of a transformer source of high voltage electrical energy, capacitor storage means for the elec trical energy, electronic rectifier means for discharging the stored electrical energy in pulse form, means for conducting the energy pulse to a spark discharge electrode immersed in a working fluid, and circulating means for flowing the working fluid past the electrode, said working fluid comprising a multiphase composition having a continuous phase of dielectric liquid and a dispersed phase of electrically conducting substantially insoluble particulates.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • Lubricants (AREA)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
US323363A 1963-11-13 1963-11-13 Electrohydraulic system and working fluids therefor Expired - Lifetime US3225252A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
DENDAT1252449D DE1252449B (enrdf_load_stackoverflow) 1963-11-13
US323363A US3225252A (en) 1963-11-13 1963-11-13 Electrohydraulic system and working fluids therefor
GB43846/64A GB1073739A (en) 1963-11-13 1964-10-27 Electrohydraulic system and working fluids therefor
NL6413035A NL6413035A (enrdf_load_stackoverflow) 1963-11-13 1964-11-09
SE13634/64A SE312879B (enrdf_load_stackoverflow) 1963-11-13 1964-11-12

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US323363A US3225252A (en) 1963-11-13 1963-11-13 Electrohydraulic system and working fluids therefor

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US3225252A true US3225252A (en) 1965-12-21

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US (1) US3225252A (enrdf_load_stackoverflow)
DE (1) DE1252449B (enrdf_load_stackoverflow)
GB (1) GB1073739A (enrdf_load_stackoverflow)
NL (1) NL6413035A (enrdf_load_stackoverflow)
SE (1) SE312879B (enrdf_load_stackoverflow)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3345843A (en) * 1964-09-21 1967-10-10 Gen Dynamics Corp Forming apparatus
US3356178A (en) * 1965-06-29 1967-12-05 Shell Oil Co Method and apparatus for seismic exploration
US3452565A (en) * 1964-11-23 1969-07-01 Rohr Corp Electric discharge machine and method of metal forming
US3491010A (en) * 1965-05-18 1970-01-20 Iwatani & Co Method for cracking liquid hydrocarbons in an electrical discharge
WO1989011665A1 (en) * 1988-05-27 1989-11-30 Natural Environment Research Council Seismic wave generating apparatus
US6113560A (en) * 1994-09-21 2000-09-05 Hmt High Medical Techologies Method and device for generating shock waves for medical therapy, particularly for electro-hydraulic lithotripsy
US20040145354A1 (en) * 2003-01-17 2004-07-29 Stumberger Walter W. Method for controlling an electrical discharge using electrolytes and other electrically conductive fluid materials
US20080112107A1 (en) * 2004-01-14 2008-05-15 Stumberger Walter W Method for controlling an electrical discharge using electrically conductive fluid materials
US10012063B2 (en) 2013-03-15 2018-07-03 Chevron U.S.A. Inc. Ring electrode device and method for generating high-pressure pulses
RU2688154C1 (ru) * 2018-03-12 2019-05-20 Дмитрий Вениаминович Воробьев Устройство для получения нанокапсул витаминов

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH478604A (de) * 1968-06-24 1969-09-30 Siemens Ag Vorrichtung zum Umformen von Werkstücken mittels Druckwellen
DE10100974B4 (de) * 2001-01-11 2004-07-08 Hmt High Medical Technologies Ag Vorrichtung zur Erzeugung von Stoßwellen
DE10125936A1 (de) 2001-05-23 2003-01-02 Hmt Ag Medizinisches Gerät
DE102009034314B4 (de) * 2009-07-23 2011-04-07 Adensis Gmbh Verfahren zur materialselektiven Zerkleinerung von Brennstoffzellenstacks

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2162823A (en) * 1935-08-16 1939-06-20 Gen Motors Corp Apparatus for producing colloidal suspensions of metals

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2162823A (en) * 1935-08-16 1939-06-20 Gen Motors Corp Apparatus for producing colloidal suspensions of metals

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3345843A (en) * 1964-09-21 1967-10-10 Gen Dynamics Corp Forming apparatus
US3452565A (en) * 1964-11-23 1969-07-01 Rohr Corp Electric discharge machine and method of metal forming
US3491010A (en) * 1965-05-18 1970-01-20 Iwatani & Co Method for cracking liquid hydrocarbons in an electrical discharge
US3356178A (en) * 1965-06-29 1967-12-05 Shell Oil Co Method and apparatus for seismic exploration
WO1989011665A1 (en) * 1988-05-27 1989-11-30 Natural Environment Research Council Seismic wave generating apparatus
US6113560A (en) * 1994-09-21 2000-09-05 Hmt High Medical Techologies Method and device for generating shock waves for medical therapy, particularly for electro-hydraulic lithotripsy
US20040145354A1 (en) * 2003-01-17 2004-07-29 Stumberger Walter W. Method for controlling an electrical discharge using electrolytes and other electrically conductive fluid materials
US20080112107A1 (en) * 2004-01-14 2008-05-15 Stumberger Walter W Method for controlling an electrical discharge using electrically conductive fluid materials
US10012063B2 (en) 2013-03-15 2018-07-03 Chevron U.S.A. Inc. Ring electrode device and method for generating high-pressure pulses
US10077644B2 (en) 2013-03-15 2018-09-18 Chevron U.S.A. Inc. Method and apparatus for generating high-pressure pulses in a subterranean dielectric medium
RU2688154C1 (ru) * 2018-03-12 2019-05-20 Дмитрий Вениаминович Воробьев Устройство для получения нанокапсул витаминов

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Publication number Publication date
DE1252449B (enrdf_load_stackoverflow)
SE312879B (enrdf_load_stackoverflow) 1969-07-28
NL6413035A (enrdf_load_stackoverflow) 1965-05-14
GB1073739A (en) 1967-06-28

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