US2038479A - Electrical dehydrator high voltage supply - Google Patents

Description

l.. DILLoNY 52,038,479 ELECTRICAL DEHYDRATOR 51am/@TAGE SUPPLY [April 21, 1936.

vFiled SIep`t. 2, i952 v Patented Apr. 21, 1936 UNITEDV STATE ELECTRICAL DEHYDRATO'B. mc

voL'rAGE SUPPLY Lyle Dillon, Los Angeles,

Oil Company of California,

Calif., assignor to Union Los Angeles, Calif.,

a. corporation of Californial Application september z, 1932, serial No. 631,534

4 Claims.

This invention relates to the-art of disrupting emulsions and particularly to a high voltagel supply means for petroleum emulsion dehydrators.

The object of this invention is to provide a 5 means for supplying an interrupted and/ or intermittent high voltage to an electrical dehydrator. It is also an object of this invention to provide a high voltage interrupted current of high intensity which will be effectual in' breaking down low resistant emulsions which heretofore have required special treatment. A further object of this invention is to provide a process for Supplyinghigh voltage, high amperage current, either interrupted alternating, or interrupted direct current or both, at random, to an electrical 'dehydratcn 'A further object' of' this invention is to provide a high voltage supply for a fishydrator which shall be inherently free and protected from dehydrator short circuits and the attendant heavy demands. A further object is to providev an electrical supply, the current output of which shall be self regulating, and limited to a predetermined maximum, independently of treater operating conditions. Aiurther object of this invention is to provide a petroleuml de- `hydrator electrical supply with equipment of moderate capacity which will be capable oivfurnishing a current oi` suflicient intensity to maintain an eiective treating potential Agradient 'throughout 'a fluid of high conductivity. This process and apparatus is particularlyadapted to the treatment of petroleum emulsions oi the water-in-oil type which have low electrical resistances and poor dielectric properties. 35 Heretofore it has been difficult to emciently hydrate emulsions of high conductivity due to their short circuiting action in the treater. To

prevent this short circuiting, dilution of the conductive lemulsion with oil of highfr resistance or of higher dielectric properties has been practiced. Even Awhen such dilution is employed, in-

termittent heavy currents are drawn by short circuiting water chains which form between the electrodes of the treater. In order to protect the electrical system against these heavy currents, it

has been necessary to connect into `the electrical circuits, reactances, which together with the norymal 4regulation of the transformer cause the said circuit to have a very pronounced 'droopingA voltage regulation characteristic. Thus, when conductive emulsion comes between the electrodes,

the current rises and the voltage correspondingly i drops to a low ineiectual value at a time when a high voltage is mostneeded. To maintain an 55 effective high voltage across sucha low resistant (Cl. 20d- 24) emulsion path, obviously would require a heavy current iiow, one which a standard installation of normal capacity would be incapable of supplying. j

This invention resides in a process and apparatus for subjecting petroleum emulsions to an interrupted and/or intermittent electrical potential. This invention further resides in a process and apparatus capable of supplying to a treater a momentary current of sufficient intensity to institutea momentary effective treating potential gradient throughout emulsions of high conductivity, without shortcircuiting or overloading the potential source. This. invention further resides in a process and apparatus whereby a quantity of electricity is transferred from a source of electrical energy to the treater without at any time allowing the said sourceto be directly lconnected to the said treater.

This invention resides inA processes and means for maintaining effective treater voltages under emulsion conditions, would 'otherwise render the treaterv inoperative.

This invention further resides in processes and apparatus to accomplish the objects set forth hereinabove.

as outlined above, which Other objects and advantages of the 4invention will be evident hereinafter. v y- The drawing diagrammatically illustrates one form of a processand apparatus embodying this invention. v f A' Fig. 1 is a diagram of the apparatus and electricalvco'nnectirm.. y

interruptor of Figi. l

Fig. 3 illustrates a modication of Fig. 1 for' operation of 4:lurality of treaters. Y

Referring to Figs, l and 2 a brief description of the operation and apparatus follows.

The apparatus comprises the following parts:

A high voltage transformer l, high voltage elec' trical capacitances or condensers 2 and 2', resist--A ance or impedance 3, rotaryswitch or interrupter rotor il, with rotating conducting segments 5 and S, stationary contact points l, t, li and 9, connecting conductors Il), ll, l2 and i3, switch 2d,

electrode. lli, metallicshell l5 of the emulsion treater it, electrode lead-in insulatorl'l; and emulsion treater inlets and outlets I8 and ,I9 respectively. One method of operation is as follows:

Rotor Il mounted on the shaft of a synchro-- nous motor and rotated at a speed which is in synchronism with the alternating high potential output of the transformerl l. Rotor 4 is thus Fig. 2 illustrates a` moml vntary position ofthe rotated so that at the time when the transformer output potential is at or near its maximum, segment 5 will'be moving through the position shown former. At this instant condenser 2 receives a full electrical charge at the transformer potential. During this charging period the circuit from condenser 2 -to the treater I6 is open, as shown in Fig. 1, there being no segment in position to bridge th'e gapbetween points 'Il and 8 in said circuit.

Immediately after the condenser 2 receives its charge, as explained above, the rapid rotation of rotor 4 carries segment 5 around to the position shown in Fig. 2, opening the circuit between the points 8 and 9, thereby disconnecting condenser 2 from transformer I, and closing the circuit between points 1 and 8, connecting the condenser across the treater electrodes. The condenser potential is then placed across the emulsion between electrode I4 and metallic treater shell I5,

. and the condenser charge is rapidly discharged therethrough by way of the completed circuit, point 8, segment 5, point l, conductor I2, treater shell I 5; electrode I4 and conductor I3.

As the rotor turns in synchronism with the alternating transformer output potential, the condenser is thus repeatedly and alternately connected to the transformer to receive a. charge, then disconnected therefrom and connected to the treater through which it discharges the previously received charge. At no time is the transformer directly connected to the treater, forthe treater receives its current only from the condenser discharge. "Therefore the maximum possible demand upon the transformer is that which is required to completely charge condenser 2, regardless of what the conductivity of the materia] in the treater` may be. Since the transformer is never in direct electrical connection with the treater, there can be no heavy current from Vthe transformer following' a short circuit between the electrodes.

The rapidity of discharge of the condenser through the treater and the value of the discharging current will depend largely upon the resistance ofthe emulsion between the electrodes. Since a condenser is capable 6livering a very heavy current for a limited time interval, it is therefore possible with this system to maintain momentarily a high potential dierence across a low resistance path such as a highly conducting emulsion. This potential can be applied repeatedly and at as rapid frequency as is necessary to accomplish thorough treatment of the low resistantl emulsion with the lapparatus of this invention, whereas with the usual arrangement with the transformer directly connected to the treater, the voltage is reduced to an ineffectual value and remains such as long as the low resistant emulsion remains in the treating zone.

By choice of design of the interrupter 4 and the value of resistance or impedance 3, the period of charging the condenser 2, from transformer' I, may be made relatively long as compared to the timeof its discharge through emulsions of'low resistance; thereby relieving the transformer of suddencharging shocks and lowering the accompanying power output peak. For example.

by lengthening the contact points of the charging contacts 8 and 9 and increasing the impedance of the charging circuit, as by impedance 3, the rate of charging of condenser 2 may be retarded. The rate of discharge of condenser 2 will be governed largely by the resistance of the emulsion in the treating space between the electrodes.

Rotor 4 may be run at synchronous speed under which .condition the condenser 2 will be charged and discharged twice per cycle, each charge at opposite polarity from thepreceding one. 'Ihis method of operation will be satisfactory, provided that the condenser is completely discharged through the treater with each connection therewith. If the resistance of the lemulsion in the treater is such, however, that a half of each cycle of the transformer output is utilized in charging condenser 2. By closing switch 20, a second condenser 2 may be connected, as shown on Fig. 1, to enableboth sides of the alternating cycle of the transformer output to be utilized, while at the same time charging each condenser unidirectionally.

With the rotor running at one half synchronous speed, and with the switch 20 open as shown in Fig. 1, an interrupted direct current is supplied to the treater. With the rotor running at synchronous speed with the sameconnections, an interrupted alternating current is supplied to the treater or the same is obtained by closing-switch 20 when the rotor is run at one half synchronous speed. Variations of the above current supply characteristics may be obtained by running the rotor at multiples of the synchronous speed with proper accompanying manipulation of switch 20; or the rotor may be run non-synchronously, producing an interrupted.

current of random polarity. Thus the electricalsupply may be adapted to produce an output of a character best suited vto the efcient treatment of the emulsion at hand.

Fig. 3 diagrammatically illustrates a method operating according to the principle .outlined' in connection with Fig. 1, whereby a number of individual treaters or a number of different pairs of electrodes in a treater can be operated, each treater 'or pair oi' electrodes receiving intermittent and successive electrical discharges. The operation of the system shown in Fig 3 is as follows: w Y y With the Arotor in the position as shown in Fig. 3, condenser 22 receives a charge from transformer 2I by way of conductor 33, resistance or impedance 34, contact point 29, rotor segment 36, contact' point 25 and return line 35. The contact points are of suilicient size to permit complete charging and discharging of the 'condensera The next position of the segment 36 following k the one illustrated here; as the rotor 24` revolves clockwise at one half synchronous speed, is that which bridges the gap between contact points 26 and 33. As this gap between 23 and 30 is bridged bysegment 36, condenser 22 discharges the previously obtained chargethrough treater 'IISA i the treaters.

42 by way o! conductors 31 and 3l. Following this, contact points 2'I and 3l are closed by the segment 36 whereupon condenser 23 receives a charge from the transformer 2|,.which charge -is immediately thereafter discharged through treater 4I by way of completing circuit conductors 43, 44 and 38, when contact points 28 and 32 are bridged; and so on, the condensers alternately receiving charges vand discharging through connection une as with switch 4u iuustrates an optional connection between condensers 22 and 23 whereby they may be made to operate in parallel, in which case the condensers will be simultaneously charged and discharged in alternating polarity. Without .connection` 33, con-` densers 22 and 23 .will operate independently without alternation of polarity of charge, i.- e.,

yeach condenser will be charged unidirectionally.

Other arrangements are obvious to one skilled inthe art, by which a plurality of treaters can be operated in a manner similar to that described above.

-allowed to take place.

High voltage transformer I may be oi- .any suitable voltage and power rating. Condenser 2 may be oi.' any suitable type, preferably with a capacity such that, at 'the frequency i charging; the maximum average charging power will be not greater than the desired output of the transformer. The interrupter 4 may be of the synchronous rectier type. -This type of rectiiler usually takes the formvot a plurality of stationary electrodes or' contact points circumierentially 'arranged with' a plurality of points rotatably mounted to move past the said stationary points. The rotatable 'points are suitably arranged and connected together 4by interconducting bars, to accomplish. when rotated, the properswitching oi.' circuits terminating at the stationary points. These 'points-the rotatable and stationary ones-do not usually make mechanical contact, but for highl voltage systems such as the one of this invention, merely pass one another withs'uch' slight clearance that the voltage therebetween is able to bridge the slight gap.

It is to be understood that the foregoing is ofoperation and that the invention is not limited thereby, but may include any method and appav`merely illustrative of one apparatus and method v ratus to accomplish the same within the scope of the invention.

l I claim as my invention:

1. A method of treating emulsions which come" prises charging a plurality o f condensers successively and discharging said charged condensers successively through a pair of electrodes in contact with emulsion to be treated, each con-l denser being isolated from the charging source during the discharging interval. y

2. A method of treating emulsions which comprises charging a plurality of condensers successively and discharging said charged condensers successively each through a separate pair of a plurality of pairs of electrodes in contact with emulsion 'to be treated, each condenser being electrically isolated from the charging source during the discharging interval.

'3. An apparatus for treating; emulsions comprlsing a plurality of pairs of electrodes in emulsion to be treated, a .source of high potential f electricity,"an electrical condenser system, and distributor means for alternately connecting said condenser system successively to said high potential source and to each pair of said electrodes in turn. A

4. In a dehydrator having electrodes, a source of high voltageyelectricalr; energy, a plurality of condensers for storing said energy, and means for alternately connecting each of said condensers to said electrodes and to said source, said means being adapted to alternately disconnect each,

of said condensers from said source and connect each of said condensers to the electrodes whereby, when one of said condensers is connected to said electrodes and disconnected from said source. another or said condensers is disconnected from the electrodes and is connected to said source.

LYLE nunon.

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