JPS60150855A - Electrostatic desalting apparatus - Google Patents

Abstract

PURPOSE:To remove impurities in the oil to be treated effectively by allowing to exhibit separating effect due to static electric force effectively. CONSTITUTION:In an electrostatic desalting apparatus for removing impurities in the oil to be treated utilizing separating effect of static electric force, at least two pairs of plate grid-shaped high voltage electrode 3, 3' arranged horizontally in a vessel 1, plate grid-shaped earthing electrodes 4, 4', an oil introducing pipe 7 for feeding the oil to be treated into the electric field of the pairs of electrode, a dispersing device 13 of a distributing pipe 6 for deflecting a part of the rising oil to counter direction, and a shielding plate 12 are provided. Thus, the oil to be treated fed to the vessel is disturbed in the electric field formed by at least two pairs of the electrode to prompt agglomeration of water drops by the effect of static electric force, and apparent strength of the electric field is reduced without elevating the electric potential of the pairs of the electrode. By this method, the electrostatic separating effect is exhibited effectively and the impurities in the oil to be treated are removed efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an electrostatic desalination device that removes impurities by utilizing the separation effect of electrostatic force.

Contained in natural crude oil or synthetic crude oil) IJum,
For desalination of salts such as potassium and dehydration of water, a method is adopted in which the oil to be treated is injected with water in advance and separated using electrostatic force. Conventionally, this method of desalination is shown in Figure 1 (G).
, Q3) is known. 1 in the figure is a desalination tank, and a transformer 2 is provided on the earthen wall of this desalination tank 1. Inside the desalination tank 1, a planar grid-like high voltage electrode 3 and a planar grid-like ground electrode 4 are arranged horizontally, and these electrodes 3.4 are suspended via an insulator 5. Further, the high voltage electrode 3 is connected to the transformer 2. A distribution pipe 6 is disposed in the desalination tank 1 so as to be located below the high voltage electrode 3, and the distribution pipe 6 penetrates the bottom of the desalination tank 1 and extends to the outside. It is connected to an inlet pipe 7 for the oil to be treated to be discharged. Furthermore, the desalination tank 1
An interface meter 8 is suspended inside to extend vertically. An oil collection pipe 9 is disposed at the upper part of the desalination tank 1 . Note that 10 in the figure is a drain port.

Next, the operation of the conventional electrostatic desalination apparatus mentioned above will be explained.

First, the oil to be treated is heated to approximately 70°C or higher using a heat exchanger, and then several washes of water are mixed in to create an appropriate pressure difference (approximately I
The oil and water are mixed by passing through a mixing valve at a rate of Ks/m 2 ). The oil mixed with water in this way is uniformly introduced into the desalination tank 1 from the distribution pipe 6 via the introduction pipe 7.

The minute water droplets mixed in the oil repeatedly coalesce with each other in the electric field formed by the high voltage applied between the ground electrode 4 and the high voltage electrode 3, and the particle size increases and they settle due to gravity. do.

In addition, sodium and potassium in the oil are dissolved into minute water droplets mixed in the oil and are partially separated from the oil. These minute water droplets also repeatedly coalesce with each other in the electric field applied between the ground electrode 4 and the high voltage electrode 30, their particle size increases, and they settle due to gravity. The level of the water thus settled is constantly monitored by the interface meter 8 and maintained at a constant level. On the other hand, the desalted oil passes through the oil collection pipe 9 at the top of the desalted tank 1 and is discharged to the outside of the tank.

However, in the above-mentioned electrostatic desalination equipment, the rising oil comes into contact with the settled water droplets, and the salts that were once separated in the washing water are entrained again, so the salt concentration in the oil to be treated increases.
This has the disadvantage that it must be treated again in an electric field and that oil is mixed into the cleaning water, making it necessary to reprocess it. In addition, water droplets that have repeatedly coalesced in an electric field and become larger will settle in the electric field only when they have grown to a certain particle size under an applied voltage. It has the disadvantage that it takes a considerable amount of time to separate.

The present invention has been made in order to eliminate the above-mentioned drawbacks, and aims to provide an electrostatic desalination device that can effectively remove impurities from oil to be treated by effectively exerting the separation effect of electrostatic force. It is.

That is, the present invention provides an electrostatic desalination apparatus that removes impurities from oil to be treated by using the separation effect of electrostatic force, which includes a container and at least two pairs arranged horizontally within the container. A planar grid high-voltage electrode, a planar grid grounded electrode, an oil introduction pipe for supplying the oil to be treated into the electric field of the pair of electrodes, and an oil inlet pipe that uniformly prevents the rise of the oil to be treated in the electric field of the pair of electrodes. The device is characterized by comprising means for directing the portion in the opposite direction.

Among the two or more pairs of electrodes, the distance between the lowermost counter electrode and the separated water surface may be any suitable value, but it is preferably greater than the distance between the lowermost counter electrodes. In the electrostatic desalination according to the present invention, impurities present in the electrostatic field cause dielectric polarization, and the movement of this causes current to be generated. For this reason, the movement of charge directly from the high-voltage electrode to the opposing ground electrode, as in spark discharge, does not involve the movement of impurities as charge carriers, so it does not waste power and causes spark discharge. It is necessary to prevent this from happening.

For example, in a uniform electric field, the threshold for spark discharge is the spark initiation electric field strength obtained by subtracting the applied voltage by the distance between the two electrodes, but normally the applied voltage is set to generate a spark discharge between the two electrodes in order to maintain a high salt removal rate. The maximum value is used. The applied voltage at this time varies depending on the water content in the oil to be treated, and is usually about 1 to 10 kV per 1 c1n.

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS. 2(A)*(B). Components similar to those of the electrostatic desalination apparatus shown in FIG. 1 described above are designated by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 2, the electrostatic desalination apparatus of the present invention has an upper stage (first stage) planar grid-like high voltage electrode 3 in a desalination tank 1, an upper stage (first stage)
A planar lattice-like ground electrode 4 of the second stage), a planar lattice-like high voltage electrode 3' of the lower stage (second stage), and a planar grid-like ground electrode 4' of the lower stage (second stage) are arranged horizontally in order from the top. There is.

Two pairs of electrodes 3, 4, 3', 4'
is located. These electrodes 3, 4, 3', 4
' are suspended via insulators 5, and the upper high voltage electrode 3 is connected to the transformer 2 above the desalination tank 1 via an insulating bushing 11, and the lower high voltage electrode 3' is connected to the desalination tank 1. 1 is connected to a transformer 2' mounted on top of the transformer 1 through an insulating bushing 11'. Further, a shielding plate 12 is provided above the high voltage electrode 3 in the upper stage. Further, a plurality of dispersers 13 are installed at regular intervals on the upper surface of the distribution pipe 6 that supplies the oil to be treated.

Next, the operation of the electrostatic desalination apparatus of the present invention will be explained.

First, the oil to be treated is introduced from the oil inlet pipe 7 and distributed by the distribution pipe 6, and is passed through the distributor 1.3 attached to the distribution pipe 6 and the shielding plate 12 above the high voltage electrode 3 in the upper stage. A circulation flow path is formed in the electric field formed by the high voltage poles 3, 3/ and the upper and lower ground electrodes 4, 4', and a downward flow is created, opposite to the main flow (upward flow) of the oil to be treated. Some occur. During this time, the impurity particles contained in the oil to be treated are polarized in the electric field, and are attracted to areas where the electric field is strong, mainly due to gradient force (resulting from the partially unequal electric field between the electrodes).
The particles move toward the vicinity of the shielding plate 12 and the vicinity of the oil-water interface. Also, polarized impurities try to form beads through interaction. Once a bead is formed, impurity particles such as small particles maintain the bead for a long time due to the attraction between polarized charges. These processes work only when an external electric field is applied, causing particles to condense one after another in the direction of the electric field on the object surface or within the liquid, and as the fluid circulates, they gather near the oil-water interface.

Particles that are very close to the sides of the mala beads become attached to each other on the sides due to the diffusion effect. In addition, there is a possibility that the beads may tilt due to disturbance during the formation of the beads. This results in branching. This role has an effect on aggregation. When particles have the same charge, their formation is inhibited by Coulomb repulsion.

When the particles become conductive, this force is lost, and the beads can be torn apart and scattered by the Coulomb force acting on the upper and lower polarized charges.

Therefore, the beads themselves must be moved away before the particles become conductive. For this purpose, the above-mentioned strong circulation channels are formed.

The alternating current electric field formed by the upper ground electrode 4 and the lower high voltage electrode 3' has the same potential as the conventional type shown in FIG. Because of the arrangement, the apparent electric field strength (average value,
(potential minus the total distance between the poles).

The impurities combined by the above action are separated from the oil to be treated, reach the aqueous layer at the bottom of the desalination tank 1, and are extracted through the discharge port 10. The processing liquid that has passed through the electric field reaches the upper part of the demineralization tank 1 by a uniform upward flow, and is collected in the oil collecting pipe 9. The upper part of the desalination tank 1 is very little affected by the electric field, and becomes a separation area where water droplets that have not coagulated and separated are simply settled by gravity.

Note that stirring of fluid in an electric field is basically based on the flow path shown in Fig. 2 (B), but there is no restriction in any way, and any flow path that can effectively utilize the gradient force from the electric field section may be used. Either is fine.

As detailed above, according to the present invention, the oil to be treated supplied into the container is agitated in the electric field formed by two or more pairs of electrodes to promote agglomeration of water droplets due to electrostatic force. At the same time, by reducing the apparent electric field strength without increasing the potential of the electrodes that apply the pair, the electrostatic force can effectively exert the separation effect and efficiently remove impurities from the oil to be treated. We can provide electrolytic desalination equipment.

[Brief explanation of drawings]

Fig. 1 (G), ω) is a schematic diagram showing a conventional electrostatic desalination device, and Fig. 2 (4), (B) is a schematic diagram of an electrostatic desalination device showing an embodiment of the present invention. be. 1... Desalination tank, 2 p 2'... Transformer, 3.3'
...High voltage electrode, 4, 4'...Ground electrode, 6...
・Distribution pipe, 7... Treated oil introduction pipe, 9... Oil collection pipe,
12... Shielding plate, 13... Distributor.

Claims (1)

[Claims] An electrostatic desalination device that removes impurities from oil to be treated using the separation effect of electrostatic force includes a container and at least two pairs of high voltage flat grids arranged horizontally within the container. An electrode and a planar grid grounded electrode, an oil introduction pipe for supplying the oil to be treated into the electric field of the pair of electrodes, and a portion of the rise of the oil to be treated in the electric field of the pair of electrodes directed in the opposite direction. An electrostatic desalination device characterized by comprising means.