US2120932A - High frequency induction dehydrator - Google Patents

Description

June 14, 1938.

L. DILLON HIGH FREQUENCY INDUCTION DEHYDRATOR Filed May 15, 1935 ATTORNEY.

Patented June 14, 1938 PATENT OFFICE HIGH FREQUENCY INDUCTION DEHYDRATOR Lyle Dillon,

Los Angeles, Calif., assignor to Union Oil Company of California,

Los Angeles, Calif.,

a corporation of California Application May 15, 1933, Serial No. 671,023

12 Claims. (01. 204-24) This invention relates to the art of separating the phases of emulsions and particularly to an electrical dehydrator for petroleum emulsions.

- Conventional treaters usually comprise a tank into which, or through which, the emulsion to be treated flows andin which a live electrode is disposed. The treating potential in the conventional treater is set up through the emulsion to be treated between the electrode and the tank wall or between the electrode and another surface grounded to said tank wall. The emulsion thus undergoing treatment is in physical contact with the electrode and the said oppositely chargedsurface, with the emulsion acting more or less as an 'electrical conductor between them, depending upon its water content, fineness of particles or other characteristics. This condition of operation tends to shortcircuit the electrical system and impair its operation. Therefore, due to their 'shortcircuiting-tendencies only emulsions covering a narrow range of characteristics can be treated in such a treater without employing special means to prevent the electrical system being rendered inoperative by shortcircuits through the emulsion.

The conventional dehydration apparatus also necessitates insulated electrical connections to the electrodes in the treating zone through the treater shell, said connections passing through a gas tightv lead-in insulator of high potential capacity. Due to the unfavorable conditions under which such a lead-in insulator is forced to operate it is a source of electrical and mechanical difficulty.

Objects of this invention are to overcome the above enumerated and other disadvantages of the common dehydration methods; to provide a novel form of treater and method of treatment which will be efficient, economical, of high capacity, simple and uniform in operation and capable of effec- AO tively treating emulsions which heretofore have been difficult if not impossible to treat by electrical methods alone; and to eliminate mechanical and electrical insulating and supply difficulties. Other objects are to provide a treater which is inherently electrodynamically and mechanically non-shortcircuiting in, its operation, which requires no electrodes in the treating zone nor leadin insulators through the treater shell into the treating zone, and in which electrical stresses through the insulating bodies therein are at a minimum, and it is a further object to provide such a treater which is capable of operating on emulsions having wide ranges of water content and electrical conductivity.

55 In general these objects are attained according to this invention through treatment only by currents and/or high potential gradients induced in the treated liquid by electromagnetic induction.

The invention is embodied in apparatus comprising an elongated annular insulating conduit through which emulsion to be treated is caused to fiow and around which an intense alternating electromagnetic field is induced. Said field is induced by a current of corresponding characteristics applied to an electrical conductor which winds spirally around the outside of said insulating conduit out of contact with the emulsion being treated, in the form of a solenoid. Means is provided for supplying said solenoid with an interrupted or intermittent high frequency high voltage. current. The field thus induced in the emulsion in .the annular insulating conduit in turn induces a counter E. M. F. of high potential around the annulus formed by the emulsion in the annular conduit. Means is provided to introduce emulsion to be treated into the treating zone in the annular insulating conduit and means is provided to withdraw treated emulsion from said conduit and pass it to a separate settling tank where separation takes place. Means is also provided for introducing gas into the treating zone in the insulating conduit to aid treatment. An auxiliary electrode system may optionally be embodied in the structure of the invention, said auxiliary system comprising a solenoid and an electrode axially disposed therein, which may be placed inside, of said insulating conduit, and in which treating potentials are induced by electromagnetic induction only.

The invention, broadly stated, comprises a method and apparatus for treating emulsions by electromagnetic induction. The invention comprises more specifically a process and apparatus for dehydrating petroleum emulsions of water in oil by inducing in said emulsion by an intense alternating electromagnetic field, closed electrical currents of high potential gradient, said induced potential gradient being sufiicient to agglomerate the water. The invention also resides in a dehydration method and means for producing an intense alternating and/ or intermittent electromagnetic inducing field. The invention further resides in a structure adapted to such a method of treatment in which high tension lead-in insulators directly into the treating zone are eliminated, electrical stresses across insulating bodies minimized and electrodes rendered unnecessary. The invention also resides in a structure in which an auxiliary solenoid and electrode system inside I of the treating zone may be employed in which tromagnetic induction.

the treating potentials are set up entirely by elec- The invention resides further in such a structure where an auxiliary solenoid is employed in stepping up the potential in said treating zone through said auxiliary electrode system. The invention also resides in combination of the automatic stirring action of the electromagnetic field upon the emulsion being treated to minimize short circuiting and to increase efficiency of treatment. The invention further resides in combination of the dynamic disrupting eflect of the magnetic field upon short-' circuiting current paths which may form in the emulsion undergoing treatment. The invention also resides in gas injection into the emulsion being treated in the treating zone combined with the above enumerated steps to increase emciency and effectiveness of electrical treatment.

Other objects, advantages and features of the invention will appear hereinafter.

In the accompanying drawing 'wherein one embodiment of this invention is illustrated:

Figure 1 is a view partially in elevation, partially in vertical section and partially diagrammatic showing the general assembly of the apparatus, including a vertical section of the electrical treater;

Figure 2 is a cross section of the treater unit taken on line 22 of Figure 1 showing the relative positions of the insulating conduit, solenoid coil and central insulating core or cylinder:

Figure 3 is a view showing the spider support attached to the cylindrical insulating 'core of the insulating conduit;

Figure 4 is a fragmentary vertical sectional detail of the modified treater showing a portion of -the auxiliary solenoid and electrode system;

Figure 5 is a cross section through the treater unit at line 5-5 of Figure 4 showing the relative positions of the solenoids, auxiliary electrodes and insulating conduit.

The apparatus illustrated comprises two main units, a treater unit A, and a separating unit B.

The treater unit A comprises an elongated vertical insulating conduit I of any suitable insulation material, the upper end of which is screwed into a flange 2 and the lower end of which is screwed into a flange 3. Surrounding and enclosing insulating conduit l is a metallic cylinder 4, adapted to contain insulating oil, the lower end of which is closed liquid tight by an annular head 5 which extends under and makes a liquid tight seal with flange 3, and the upper end ot which is closed liquid tight by an annular head 6 which makes a liquid tight seal with flange 2. The top 1 of the treater is supported by and makes a gas tight connection with flange 2 and annular head 6, and forms an enlarged upper continuation of conduit I. The top I is closed by a bumped head 8 which makes a gas tight seal thereon. A T connection 9 is flanged to the lower end of conduit I and cylinder head 5 through the medium of the flange 3 and forms a lower extension and outlet for conduit I. An insulating cylindrical core III with rounded or tapered ends I2 is coaxially placed within the insulating conduit I to form an annular passage I3 between said cylinder and said conduit. Insulating cylindrical core III is supported at top and bottom by spiders I4 which extend out between member III and the ends of conduit I, being retained in the respective flange connections.

A solenoid I6, formed of a number of turns of a. large electrical conductor is positioned around the middle of insulating conduit I. Electrical connections to said solenoid I8 are made from an external current source through lead connections l1 and petticoated insulators I8, said insulators extending through the upper cylinder head 6.

In Figure 4, there is shown an optional arrangement or the treating zone structure in which the insulating cylindrical core III is replaced by an auxiliary solenoid I 9 .and an auxiliary electrode 20 positioned inside of insulating conduit I. Auxiliary solenoid l9 and electrode 20 are not electrically connected to the external solenoid I6 but are in inductive relation thereto.

An emulsion inlet is provided through a pipe 2| into the top 1 of the treater. The emulsion outlet from the treater is formed by T 9 which leads into the lower portion of a settling tank 22 of unit 13. A. gas outlet fromthe treater is provided at the top through pipe 23. A gas injection inlet 24 is provided at the bottom of the treater through a head 25 on T 9, pipe 24 having an up-turned end 26 centrally positioned be low insulating conduit I and insulating cylindrical core III.

To allow for expansion of oil and at the same time maintain the annular chamber in the cylinder 4 entirely filled with oil under varying conditions of temperature, a pipe 28 connected with cylinder head 6 leads to an expansion chamber 29, which is partially filled with oil making a liquid seal with the down-turned portion of pipe 28 therein. In the upper end of expansion chamber 29, an air space is maintained communicating with the atmosphere through breather pipe 30 and an air drier 3|. Air drier 3I contains a chemical, such as calcium' chloride, which has the ability to remove moisture from the air. Pipe 32 with valve 33 may be placed at the lower end of cylinder 4 for draining the oil therefrom.

The separating unit B comprises the settling tank 22 which receives treated emulsion from the treater A through the T connection 9. For drawing off separated water from thesettling tank 22, a drain pipe 35 is provided in the bottom thereof connecting with a water leg 36, funnel 31 and water disposal line 33. Valve 39 in water leg 36 serves to regulate the rate of water drainage. Valve 36' between pipes 35 and 38 serves when opened to allow complete drainage of settling tank 22 through pipe 38 when desired. A pressure equalization and common vent line 40 connects thetop of the treater unit A through gas outlet line 23 with the top of the'settling tank through a connection 4| to allow the liquid level indicated by broken line 42 in treater unit A to be governed and maintained by the liquid level 42 in settling tank 22. Excessgas is discharged from line 40 past a pressure relief valve 43 which serves to prevent excess pressures from being built up in the system. Water leg 36 also is connected to gas lines 40, by pipe 44 to equalize the pressure therebetween and eliminate the possibility of treater tank 22 being entirely drained in event the emulsion supply through the treater should materially decrease or fail. Dry oil is removed from settling tank 22 through line 45 located near the top on the liquid level 42. Broken line 42 is extended through treater unit A and indicates the approximate liquid level also maintained there. V

Interrupted high frequency electric current in the form of condenser discharges is supplied to solenoid I6 by way of electrical-conductors 50, lead-in insulators IB-and leads IT. The electrical supply system to the treater comprises a transformer 52, a condenser 54 connected across the secondary of said transformer through impedances 55 and 56 and electrical conductors 58. Low voltage alternating current is supplied to the transformer primary from electrical conductors 60 through impedance 6|. A spark gap 62 is provided across which the condenser 54 discharges through-the solenoid H5 in the treater field, by way of jconductors 50, as previously stated.

The operation of the dehydrator is as follows: The emulsion enters the top I of the treater unit A through emulsion inlet pipe 2|. From the top 1 the emulsion, the top surface of which is shown at 42, flows down through the annular passage between the insulating conduit l and the insulating cylindrical core l0. From the annular passage between insulating conduit l and insulating cylindrical core Ii) the treated emulsion passes into T connection 9 and from there into the tank 22 of the separating and settling unit B. The emulsion while passing through that portion of the conduit around which the solenoid I6 is wound, is acted upon by an intense high frequency electromagnetic field set up by high frequency alternating current flowing through said solenoid. This high frequency electromagnetic field induces circumferential high potential gradients directly in the said annular stream of emulsion said potential gradients resulting in the breaking of the emulsion and agglomeration of the water particles. When the said circumferential high potential gradients occur in emulsions of moderate or high conductivity, circumferential shortcircuiting currents tend to form and flow through closed circular paths formed by the agglomerated water chains. When this condition tends to occur, an electrodynamic force incidentally comes into play between the initial shortcircuiting current and the electromagnetic field which induces it, tending to expand the diameter of said closed circumferential paths and thus to disrupt them immediately. Settling and separation of the thus treated emulsion takes place in settling tank 22 of the separating and settling unit B. The dry oil rises to the top and is withdrawn through outlet pipe 45, and the water settles to the bottom and is withdrawn through water drain 35, water leg 36, funnel 39, and water disposal line 38.

In some cases it has been found that injection of gas into the emulsion undergoing treatment in the treating zone is advantageous in increasing its efficiency and effectiveness. Pipe 24-26 serves as a means for such introduction of gas into the lower end of insulating conduit I from where it rises in finely divided bubbles countercurrent to the downward flowing emulsion stream through the treating zone. The gas thus injected continues upward through the emulsion into the treater top 'I where it disengages from the liquid therein at liquid surface 42, passes into the gas space thereabove and is vented from the treater through vent pipes 23 and 40. Gas which is evolved by the oil in the top of settling tank 22 is vented therefrom through pipes 4| and 40, all these gases being passed to any suitable gas disposal system. Gas vent pipes 23, 40 and 4|, in addition to the above, serve to equalize the pressures in the treater unit and settling tank so that the liquid level in each will be approximately the same height. The liquid level in the treater unit indicated byline 42 will thus be regulated and maintained by the liquid level in the settling tank. Pressure relief valve 43 on gas disposal line 40 serves to relieve the pressure in the treater system if it rises to a value substantially above atmospheric.

The enclosing cylinder 4 around insulating conduit l is provided to relieve, partially, the stress imposed upon it by the pressure of the emulsion passing therethrough. Cylinder 4 also provides a mechanical protection to insulating conduit I which may be of fragile material, guarding it against accidental breakage, and a means of restraining or restricting the flow of emulsion therefrom in case said conduit should fail for any reason. The annular space within cylinder 4 around conduit l is entirely filled with an insulating fluid, such as transformer oil. Provision for taking care of expansion and contraction of the said insulating fluid is made in the expansion drum 29 as above described.

In the operation of the electrical equipment, the primary of the high voltage transformer 53 is supplied with low voltage current through supply lines 60 and impedance Bl. The condenser 54 is charged to a high voltage by the high voltage output of the transformer secondary through impedances 55 and 56 and electrical conductors 58. Condenser 54 is shunted by the solenoid inductance I6, the circuit thereto being completed through leads l1, lead-in insulators l8, electrical conductors 50 and series spark gap 62. The circuit just outlined comprising condenser 54, inductance l6 and spark gap 62, with the enumerated electrical connections therebetween, constitutes an electrical oscillatory circuit, the

. frequency of oscillation of which depends upon the values of said inductance and said condenser capacity. The width of gap 62 is adjusted so that when the charge in condenser 54 is at or near the maximum value, the air dielectric therebetween will break down allowing a high frequency oscillatory discharge of said condenser through solenoid l6. In some cases where the energy transfer to a highly conductive emulsion is great the high frequency oscillations are suppressed thereby, and the condenser dischar e under such conditions occurs in a single impulse of steep fronted wave form. Gap 62 as shown in the drawing is of the fixed spherical type, but other types may be used, such as the rotary or the synchronously interrupted type. Since the condenser charging current is of a low frequency alternating characteristic, the condenser 54 will be intermittently charged and discharged at a corresponding frequency and thus the condenser discharge through solenoid IE will be intermittent.

With this type of electrical supply it is possible to apply extremely high peaks of energy to the emulsion undergoing treatment.

In some cases where it is desired to apply a much higher voltage to the emulsion than can be induced therein in an emulsion stream of an annular form, which comprises in effect a one-turn electrical circuit, the insulating cylindrical core I0 is removed and an auxiliary solenoid l9 and electrode .20 is substituted therefor (Figure 4). Auxiliary solenoid l9 may have any number of turns but where it is desired, as stated above, to increase the applied potential it may have a greater number of turns than solenoid l6 and being in inductive relation with solenoid IE will, therefore,when it has a greater number of turns, have a higher voltage induced in it than that which is applied by the electrical supply system across the said solenoid l6. Since electrode 20 is connected to one end of said solenoid I9 and extends axially therethrough, electrical potentials will exist between it and each turn of said solenoid, said potentials being progressively greater towards the open end of said solenoid and said electrode.- The maximum potential will exist between the open end of solenoid I9 and electrode 20, and will bear a ratio to the voltage supply to the solenoid l6 equal to the ratio of the number of turns on the respective solenoids.

Impedance 5| serves to cushion the electrical shocks which are transmitted through the transformer 52 from the electrical treater circuit to the supply circuit 60. Impedances 55 and 56 also serve the same purpose in addition to shielding the transformer end turns from the high frequency electrical surges in the condenser circuit and also to limit the flow of current from the transformer following each breakdown of gap 62. Impedances 55, 56 and Bi may have any ratios of inductive to ohmic resistance therein but preferably they are largely inductive with the ohmic resistance practically negligible.

The transformer secondary voltage may range from 10,000 to 30,000 volts; condenser 54 may have a capacity ranging from 0.03 mi. to 0.1; solenoid I B may have any suitable number of turns but preferably, as few as possible conducive to efiicient operation of the oscillatory circult and efiective distribution of the magnetic field through the emulsion.

It is a well known principle that an electric current in a magnetic field is acted upon electrodynamically. This principle applies beneficially in the treater of this invention in reducing shortcircuiting tendencies in operation with shortcircuiting emulsions. Thus when crcumferential shortcircuiting current paths form around the annulus of emulsions undergoing treatment in the electromagnetic field, an outward radial force is electrodynamically applied thereto which aids in quickly disrupting said paths and preventing their complete formation. The electrodynamic action 2 inches to 4 inches correspondingly. Insulating conduit l and cylindrical core l0 may be constructed of bakelite, pyrex, porcelain or other suitable insulating material.

The insulating cylindrical core ill in the insulating conduit I as shown in the drawing FiguPe 1 may be omitted and the treater operated without it, but it is desirable for the reason that it serves to reduce the cross-sectional area of the emulsion annulus through which the induced treating currents fiow, thus increasing the unit potential gradient throughout the emulsion to be treated, and it serves to confine the emulsion to that part of the conduit I where the electromagnetic field is mosteifective. a

In some cases enclosing cylinder 4 and the insulating liquid therein may be omitted and the treater operated without any protection around the insulating conduit I. In this case there is no need for lead-in insulators l9 and 20 electrical connections being made direct to the solenoid I5.

It is to be understood that the foregoing is merely illustrative of one apparatus and method of operation and that'the invention is not limited thereby but may include any method and apparatus to accomplish the same within the scope of the invention.

' I claim:

1. A process for treating emulsions comprising tense electromagnetic field impulses corresponding to said electrical surges, flowing the emulsion to be treated through said pulsating electromagnetic field whereby electrical currents are induced in emulsion of suflicient intensity to agglomerate water particles in said emulsion, injecting gas into the emulsion in the zone of said pulsating electromagnetic field and settling and separating the emulsion constituents.

2. A process for treating emulsion comprising passing the emulsion to be treated in contact with a solenoid in inductive relation to an alternating electromagnetic field and subjecting said emulsion while in said field to the potential induced in said solenoid by said field.

3. Apparatus for treating emulsions comprising a solenoid, a vertically disposed annular insulating conduit forming an annular passageway through said solenoid, a gas tight chamber communicating with the top of said insulating conduit, an enclosing tank surrounding said insulating conduit adapted to be filled with insulating oil, means to supply emulsion to be treated to the upper end of said insulating conduit, means to withdraw treated emulsion from the lower end of said conduit, means to withdraw gas from said gas tight chamber, and means to supply an alternating electric current to said solenoid.

4. Apparatus for treating emulsions comprising a solenoid, an insulating conduit forming a passageway through the field of said solenoid, a second solenoid inside of said conduit in said passageway, coaxial with said first mentioned solenoid and with said conduit, said solenoids being in inductive relation with one another, a cylindrical electrode axially disposed within said secand mentioned solenoid and electrically connected thereto, means to pass a high frequency alternating current through said first mentioned solenoid and means to flow emulsion tube treated through said conduit between and in contact with said electrode and said second mentioned solenoid.

5. Apparatus for treating oil and water emulsions comprising a solenoid inductance having a number of turns of spirally wound conductor, means to impress a radio frequency alternating potential across said solenoid whereby a high voltage drop per turn of said solenoid conductor is maintained, means to pass emulsion to be treated through the radio frequency electromagnetic field thus induced by said solenoid, whereby a potential gradient sufiicient to agglomerate the water phase is induced in said emulsion and means to separate the water from the oil.

6. Apparatus for treating oil and water emulsions comprising a solenoid inductance, a condenser, means -to electrically charge said condenser, means to periodically discharge said electrically charged condenser through said solenoid, coaxial non-magnetic insulating cylinders to define an annular passage through the field of said solenoid, means to pass emulsion to be treated through said annular passage whereby the said emulsion is subjected to the periodic magnetic field thus induced by said solenoid and the water phase is agglomerated and means to separate the water from the oil.

'7. Apparatus for treating oil and water emulsion comprising a solenoid inductance having in the order of two and one-half turns of spirally wound conductor, the turns being spaced from one another, means to impress a high frequency electric potential upon said solenoid inductance whereby a high potential drop per turn of said solenoid can be maintained means to pass the emulsion to be treated through the high frequency electromagnetic field thus induced by said solenoid, whereby a potential gradient suflicient to agglomerate the water phase is induced in the said emulsion and means to separate the water from the oil. 4

8. Apparatus for treating oil and water emulsions comprising a solenoid inductance having in the order of two and one-half turns of spirally wound conductor, a condenser having a capacity in the order of 0.1 microfarad means to charge said condenser to a the order of 10,000 volts, means i to discharge said condenser through said solenoid inductance, means to pass the emulsion.,:-'t6be treated through the magnetic field induced around said solenoid incident upon said= condenser discharge and means whereby the water phase of the emulsion is agglomerated and means to separate the water from the oil. 9. A process for dehydrating emulsions comprising inducing in the emulsion by an electromagnetic field of varying intensity a. potential gradient sumcient to cause disruptive discharges within the emulsion, whereby the water phase rating the water from the'oil.

is agglomerated, and settling and separating the water from the oil.

10. A process for dehydrating emulsions comprising inducing in the emulsion by an electromagnetic field of varying intensity a potential gradient sufllcient to cause disruptive discharges within the emulsion, whereby the water phase is agglomerated, injecting gas into the emulsion in the zone of said induced disruptive potentials whereby the disruptive discharges are reduced in frequency, and settling and separating the water from the oil.

11. A process for dehydrating emulsions comprising inducing in the emulsion by an electro-- magnetic field of varying-intensity a potential gradient normally sumcient to cause disruptive discharges within the emulsion, whereby the water phase is agglomerated and separating the water from the oil.

12. A process for dehydrating emulsions comprising inducing in the emulsion by an electromagnetic field of varying intensity a potential gradient normally sufficient to cause disruptive discharges within the emulsion whereby the water phase is agglomerated, suppressing said disruptive discharges by movement of the current paths thereof in the emulsion and settling and sepa- LYLE DILLON.

Images