SU1717167A1 - Electrocoalescence apparatus for water/oil emulsions - Google Patents

Abstract

The invention relates to devices for treating a water-oil emulsion in an electric field. The purpose of the invention is to increase the efficiency of the process by increasing the rate of coalescence of the droplets. The electrocoaler machine contains a grounded cylindrical body with inlet and outlet fittings and a cylindrical electrode coaxially arranged in it, provided with rods located along it at a distance from it with rods with a diameter smaller than the electrode diameter. The electrode rods are fixed in transverse partitions, the diameter of which decreases, and the pitch between them increases in the direction towards the outlet fitting. 3 il.

Description

The invention relates to devices for treating a water-oil emulsion in an electric field and can be used in the oil refining, gas and other sectors of the industry to intensify the processes of desalting and dewatering petroleum and various petroleum products.

The purpose of the invention is to increase the efficiency of the process by increasing the rate of coalescence of water droplets.

This goal is achieved by the fact that the Electrocoalercing apparatus for a water-oil emulsion, containing a grounded cylindrical body with inlet and outlet fittings and a cylindrical electrode coaxially located in it, along which rods with a diameter smaller than the electrode diameter are located, is provided with transverse partitions, the diameter of the partitions decreases to the exit nipple, and the step between

they increase to the outlet fitting, with the rods fixed in the transverse partitions.

The speed of the process of coalescence of water droplets in an oil emulsion that is in an electric field depends on the distance between these droplets. During coalescence, the droplets merge with each other, their number decreases, the distance between the droplets increases, and therefore the speed of the process of coalescence of water droplets in the emulsion decreases sharply as the flow of the emulsion in the apparatus moves. With the passage of the emulsion against each of the partitions in the device is the dispersion of the largest drops. The number of drops increases. The distance between them is reduced and the speed of the coalescence process after the emulsion has passed the gap between the bulkhead and the housing increases. As a result, the efficiency of the device increases,

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FIG. 1 shows the proposed electrocoalescent apparatus, a longitudinal section; in fig. 2 is a section A-A in FIG. one; in fig. 3 is a graph of the change in the rate of the process of coalescence of water droplets along the emulsion along the electrode.

The device contains a grounded cylindrical body 1 with an input 2 and an output 3 unions. A cylindrical electrode 4 is placed along the axis of the apparatus. The rods 5, whose diameter is less than the electrode diameter, are placed along it. The rods 5 are fixed in transverse partitions 6, which the electrode 4 is provided with. The diameter of the partitions 6 decreases, and the pitch between them increases in the direction towards the outlet fitting. Electrode 4 is connected through a bushing 7 to a high-voltage transformer 8. The lower end of the electrode 4 is fixed on the supporting insulator 9 mounted on the grid 10.

The device works as follows.

Water-oil emulsion is fed through nozzle 2. The passage through the gap between the electrode under voltage and the grounded housing, the emulsion is processed in an electric field and removed from the apparatus through nozzle 3.

The design provides optimal conditions for the implementation of the process of coalescence of water droplets in a water-oil emulsion.

In an electric field, coalescence of the water droplets contained in the emulsion occurs, with the fusion of the droplets, increasing their size and decreasing the number. The efficiency of this process depends on the intensity of the electric field, the number of drops per unit volume of the amulsion, and their size. The intensity of the field depends not only on the voltage on the electrode, but also on the radius of curvature of the electrode elements and the distance between these elements and the housing. In the apparatus, the field strength varies greatly in the radial direction: in the volume between the electrodes 4 and the rods 5, it is very low; in most of this volume, the electric field is practically absent (electrodes and rods are at the same potential); near the surface of the rods 5 due to the small radius of curvature of these rods, the field strength is the highest; moving away from the bar surface, the floor strength decreases. An electric field of the highest intensity exists between the edges of the partitions 6 and the casing.

When the emulsion moves in the apparatus q as a result of the coalescence of the droplets, the speed of the coalescence process rapidly decreases as a result of a decrease in the number of droplets and

increase the distance between them. The absolute value of this velocity at different points over the cross section of the apparatus varies greatly depending on the intensity of the electric field. In those areas

0 where the speed of the process is the highest, some of the droplets are enlarged to sizes close to equilibrium, i.e. maximum possible under these conditions.

When evaluating the operation of the apparatus should

5 to keep in mind that a polydisperse emulsion containing fine highly mineralized formation water with a particle size from a few micrometers to several tens of micrometers and coarse washing water is put into the apparatus. Large drops coalesce faster than small ones. Therefore, in the course of the emulsion in the apparatus, the rate of coalescence of formation water droplets with washing drops decreases even faster than the average rate of coalescence.

In the annular gap opposite the partitions, the emulsion speed and intensity of the electric field are the highest.

0 Here there is a process of coalescence of the smallest droplets, which do not coalesce in a weaker field, or the process of dispersion of the largest droplets, the size of which is larger than the critical one, can exist in the field of a given intensity and at a given flow rate. As a result of this dispersion behind the partition, the amount of water droplets in the emulsion is greater than before the partition, and the speed

0 process increases (Fig. 3).

A reduction in the diameter of the electrode partitions 6 in the direction towards the outlet fitting ensures that larger and larger water droplets remain in the emulsion and, at the exit of the apparatus, a sufficiently homogeneous emulsion with large water droplets easily separated in the settling unit. Increase step between partitions towards the output

0 fitting provides a greater depth of coalescence process for a given length of the apparatus, since the process speed drops from the partition to the partition and to obtain the required depth is necessary

5 more time In the case of a constant step. between the partitions do not have time to coalesce smaller drops of water.

Thus, the device provides the highest average process speed and optimal conditions for the implementation of the process of coalescence of water droplets in a water-oil emulsion.

Fo rmula and z oo ria and Electrocoalescent machine for water-oil emulsion, containing a grounded cylindrical body with inlet and outlet fittings and a cylindrical electrode coaxially arranged in it, along which

rods with a diameter smaller than the diameter of the electrode are located, characterized in that, in order to increase the efficiency of the process, the apparatus is provided with transverse partitions, the diameter of the partitions decreases towards the outlet fitting, and the spacing between them increases towards the output fitting, while the rods are fixed in the transverse partitions.

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Editor And / Casarda

Compiled by O. Kal Kalin

Tehred M.MorgentalKorrektor O. Kravtsova

speed coessection fig.Z

Claims (1)

Claim An electrocoalescing apparatus for a water-oil emulsion containing a grounded cylindrical body with inlet and outlet fittings and a cylindrical electrode coaxially located in it, along which rods with a diameter smaller than the diameter of the electrode are placed at a distance, characterized in that, in order to increase the efficiency of the process, the apparatus is provided with transverse 5 partitions, 'the diameter of the partitions decreases to the outlet fitting, and the step between them increases to the outlet fitting, while the rods are fixed in transverse the cities.