RU2452551C1 - Device for separation water-oil emulsions in electric field - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to separation of water-oil emulsions and may be used in oil processing and chemical industries, etc. Proposed separator comprises housing equipped with raw stock distributors and manifolds for discharge of purified oil product and separated water. Vertical external electrodes made up of plates and rod electrodes arranged there between and suspended to dry oil distribution manifold under dry oil flow injectors are connected via rectifier to transformer.

EFFECT: higher quality of separation.

3 dwg

Description

A device for the separation of oil-water emulsions in an electric field can be used in many industries for the separation of emulsions such as water in oil, especially in the oil and gas complex for the dehydration of persistent oil-water emulsions.

Known "ELECTRICAL TREATER" [Patented Dec. 29, 1931 1,838,926 HARMON F. FISHER, ELECTRICAL TREATER, Application filed June 23, 1927, Serial Ho. 200,877, Renewed September 29, 1931], made in the form of a vertical apparatus in which several external electrodes made in the form of Venturi tubes are installed in the horizontal partition. The role of the central electrodes is performed by pipes ending with nozzles. Through these pipes from nozzles, the dry oil is distributed downstream, washes the pipes from the outside, prevents the formation of structures from drops of water contained in the injected oil, and prevents short circuits of the electrodes. The electrode system is assembled in a partition installed in the guide shell, closed at the top with a conical screen and suspended on insulators above the guide conical screen.

The disadvantages are that the vertical cylindrical body effectively dehydrates the water-oil emulsion in small quantities and the productivity of vertical electric dehydrators per unit volume is less than that of horizontal ones. In addition, the vertical arrangement of electric dehydrators makes it difficult to maintain, repair and replace equipment items.

In addition, the patent "SEPARATION OF EMULSIONS WITH ELECTRIC FIELD" (separation of emulsions in an electric field) is known [United States Patent 4308127 Prestridge et al. Dec. 29, 1981 Inventors: Floyd L. Prestridge, Mounds, Okla .; Ronald L, Longwell, Boise, Id. Assignee: Combustion Engineering, Inc., Windsor, Conn. Appl. No .: 230,227 Filed: Feb. 2, 1981 Related U.S. Application Data Continuation-in-part of Ser. No. 130,878, Mar. 17, 1980. Int. CI.2 B01D 17/06; C10G 33/02 U.S. CI 204/302; 204/188], according to which equal amounts of an oil-water emulsion are fed into a cylindrical horizontal body through two pipelines. The incoming emulsion is evenly distributed along the length of the horizontal housing with pipes fixed in flat, vertical, grounded electrodes installed parallel to the axis of the housing. Grounded electrodes mounted parallel to the housing axis are separated from the electrode system, mounted perpendicular to the housing axis, by a dielectric shield. The emulsion coming through grounded pipes enters an inhomogeneous field with an intensity that decreases in the direction of fluid motion between flat, vertical electrodes of different sizes mounted perpendicular to the axis of the housing.

Of the known closest in technical essence is the copyright certificate "Horizontal Electrodehydrator" [a.s. 1813485 (USSR), class B01D 17/06, publ. in B.I. 1993, No. 17, L.A. Dritov, K.V. Tarantsev, L.M. Razzorilov], in which in a cylindrical case two systems of diverging flat electrodes made of sheet metal are combined into three horizontal packets, they are mounted in fan holders fan-shaped, diverging at an angle of 10-20 °. The electrodes are electrically insulated by dielectric plates fixed between them. The central electrodes in the bags are connected to a current source, the external ones through the body are grounded.

The disadvantage is that the proposed design does not fully use the flow of oil-water emulsion to prevent the formation of structures from water droplets, leading to a short circuit of the electrodes.

The present invention is directed to the implementation of the design in a horizontal housing to obtain almost any performance by increasing the length of the apparatus with the same diameter, to use an inhomogeneous field to increase the intensity of processing and the degree of dehydration of oil, and also to use the directed flow of working fluid flows to prevent the formation of structures from water droplets leading to a short circuit of the electrodes.

The technical result is to increase the intensity of processing and the degree of dehydration of oil at almost any productivity of the device.

This is achieved by the fact that in a device for separating water-oil emulsions in an electric field containing two systems of electrodes made of metal in a cylindrical body, mounted in horizontal bags, are installed in dielectric holders, the central electrodes in the bags are connected to a current source, and the external electrodes are through the body earthed, according to the invention, external electrodes made of sheet metal are combined in packages suspended on insulators, and are electrically insulated by dielectric with a hydrophilic coating, they converge from top to bottom with the formation of a confuser, then they are parallel to each other, nozzles are installed here, and then diverge with the formation of a diffuser, the central electrodes are made of vertical rods suspended from the pipes of the dry oil distribution manifold made of dielectric material, and ending with nozzles for supplying dry oil, the electrodes are connected to the transformer through rectifiers. After treatment in an electric field, the oil-water emulsion passes between the precipitation shelves.

The introduction of new elements and the relationships between them provides a solution to the problem.

Figure 1 schematically shows a General view of a device for separating an emulsion of immiscible liquids in an electric field.

The device (figure 1) contains:

1 - housing;

2 - collector of the original emulsion;

3 - collector for water collection;

4 - fender plates;

5 - liquid interface;

6 - a collector for collecting dry oil;

7 - contact node.

Figure 2 schematically shows the design of the contact node of the device for separating the emulsion of immiscible liquids in an electric field.

Contact node (figure 2) includes:

8 - precipitation shelves of hydrophilic dielectric;

9 - diffuser parts of the external electrodes;

10 - vertical parts of the external electrodes;

11 - confuser parts of the external electrodes;

12 - collector distribution of dry oil to the nozzle;

13 - dielectric screen;

14 - suspension insulators of the external electrode;

15 - pipe manifold distribution of dry oil;

16 - nozzle;

17 - suspension insulators of the central electrodes;

18 - a central electrode;

19 - precipitating parts of the external electrodes;

20 - metal precipitation shelves with a hydrophilic coating.

Figure 3 schematically shows the structure of the flows in a device for separating an emulsion of immiscible liquids in an electric field.

Figure 3 shows the flows:

I - input of the initial oil-water emulsion;

II - from the collectors of the distribution of the initial oil-water emulsion along the walls of the housing;

III and IV - crude oil injected into the working space between the electrodes;

V - dry oil to the collector of dry oil;

VI - oil output from the collector of dry oil;

VII - return of a portion of the oil flow from the dry oil collection manifold to the nozzles of the dry oil distribution manifold;

VIII - water droplets flowing down the precipitation surface of the external electrode and precipitation shelves;

XI - large drops of water deposited in the water layer;

X is the outlet of water from the collector of water collection.

Moreover, in the lower part of the horizontal cylindrical body 1, below the interface of the liquids, there are two distribution manifolds 2. The holes in the collector pipes are made on their lower semicircles, and the baffle plates 4 are located under the lower generatrix of the collector. The holes made on the lower semicircle of the collectors 2, on the one hand, and the baffle plates 4 direct the flows of oil-water emulsion along the walls of the apparatus.

Above the interface of liquids 5 are metal precipitation shelves 20 with a hydrophilic surface coating and precipitation shelves 8 of a hydrophilic dielectric. This helps to accelerate the coalescence of droplets on the surface of the shelves.

A composite external electrode, consisting of precipitating 19, diffuser 9, vertical 10, confuser 11 metal plates, is connected to an AC transformer. The electrodes are connected to a step-up transformer through rectifiers. The technical result is the use of a pulsating unidirectional field. Precipitation shelves 20 made of metal with a hydrophilic, dielectric coating, precipitation shelves 8 made of dielectric material, and the interface of liquids 5 can be considered as separate electrodes. This allows you to create secondary electric fields between the precipitation shelves and the interface of the liquids.

The external electrodes are made of plates 9, 10, 11, 19, the role of the central electrodes is performed by rod structures suspended from the pipes of the dry oil distribution manifold 12 made of a dielectric material (for example, fluoroplastic). Under each nozzle is a vertical metal rod. All the rods of the central electrodes are combined in a common design, connected to a transformer.

A device for separating an emulsion of immiscible liquids in an electric field operates as follows.

In the housing 1 (figure 3) through two collectors 2 is fed a water-oil emulsion. The holes in the reservoirs 2 and the baffle plates 4 direct the flow of emulsion II along the walls of the housing 1. At the same time, through the dry oil manifolds 12, through the pipes, through the nozzles 16, a dry oil flow enters the housing. These flows prevent the formation of structures from droplets of water contained in the injected oil-water emulsion V, and prevent short circuits of the electrodes. The flows of dry oil and injected water-oil emulsion IV together pass through a pulsating unidirectional electric field. Under the influence of electric field forces, the adsorption shells around water drops are destroyed and their coalescence is destroyed. As a result, the water droplets are enlarged and move downward by gravity. The use of precipitation shelves 8, 19 and 20 can significantly reduce the path of water droplets to deposition, and hence the deposition time. The load per unit volume increases. Drops of water merge on the hydrophilic surface of the plates 8, 19, 20 (stream VIII), flow down (stream IX) and collect in a layer of water located at the bottom of the apparatus.

In the casing of the apparatus, the circulation of the oil-water emulsion is carried out as follows (Fig. 3): from the collector 2 up the walls of the casing (stream II). Part of the flows in the contact node 7 (flows III and IV). In the middle part of the hull, due to the increase in the horizontal cross-sectional area, the speed decreases and droplets move to sedimentation shelves 8, 19, 20. Wet oil is injected into the contact unit, and dry oil V is cut off by screen 13 to the oil collection manifold 6.

Dry oil is discharged from the housing 1 through the collector 6. At the output, part of the stream VII is separated and returned through the collectors 12 through pipes to the nozzles 16 to create flows of dry oil between the electrodes. Part of stream VI is withdrawn for further processing. Water is discharged from the housing 1 through the collector 3 (stream X).

Three working zones can be distinguished in the apparatus: - separation of large drops of water when passing through a layer of water; - destruction of the adsorption shells and the coalescence of water droplets between the plates of the electrodes; - precipitation of water droplets in the gravity field above the precipitation shelves.

The proposed device allows you to maintain a stable circulation of liquids in the working volume of the device; reduce flow turbulence; use a transformer to create a pulsating unidirectional field; create intermediate electric fields between precipitation shelves; implement the design in a horizontal case, thereby obtaining almost any performance by increasing the length of the apparatus with the same diameter.

Claims (1)

A device for separating water-oil emulsions in an electric field, containing two systems of electrodes made of metal in a cylindrical body, combined in horizontal packages, installed in dielectric holders, central electrodes in packages connected to a current source, external electrodes through the body are grounded, characterized in that external electrodes made of sheet metal are combined into packages suspended on insulators, electrically isolated by a dielectric, hydrophilic coating, they are on top the bottom converges with the formation of a confuser, then they are parallel to each other, nozzles are installed here, and then diverge with the formation of a diffuser, the central electrodes are made of vertical rods suspended from the pipes of the dry oil distribution manifold made of dielectric material and ending with nozzles for supplying dry oil , the electrodes are connected to the transformer through rectifiers.

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