JP4576548B2 - Centrifugal liquid-liquid separation device and separation method - Google Patents

Description

  The present invention relates to a centrifugal liquid-liquid separation apparatus and separation method, and more particularly to an apparatus and method for efficiently separating a plurality of liquids having different specific gravities such as oil and water with a simple structure.

  Centrifugation is widely used as a method for separating a solid and a liquid or a plurality of solids having different specific gravities. Many conventional types of centrifuges have been developed and used. However, as a centrifuge having a relatively simple structure, a centrifuge containing a solid content from an upper opening of a rotating separation tank is used. Treated water is introduced and solid content with a large specific gravity is pressed against the inner wall of the separation tank by centrifugal force. On the other hand, the liquid in the water to be treated moves along the inner wall of the separation tank because of its low specific gravity, and is taken out from the opening and solidified. There is a type of device that separates liquid and liquid.

In addition to centrifugation including these solids, there is separation of liquids having different specific gravity, that is, centrifugal liquid-liquid separation. This centrifugal separation requires a special separation means because it cannot adopt a conventional method of separating the solid content having a large specific gravity against the inner wall of the separation tank by centrifugal force.
For example, in Japanese Patent Laid-Open No. 6-285389, a plurality of longitudinal separators are radially arranged around a cylindrical separator axis (paragraphs 0007, 0010 and FIGS. 1 and 2). In this apparatus, the stock solution flows in the axial direction between the longitudinal separation plates 5 arranged radially. While flowing in the axial direction, a liquid having a large specific gravity (hereinafter referred to as “heavy liquid”) receives the action of a centrifugal force and moves to the radial outer diameter side along the separation plate, while a liquid having a small specific gravity (hereinafter referred to as “light liquid”). ) Moves to the inner diameter side and the two types of liquid are separated. This device has a drawback that the structure is complicated and the separation of heavy and light liquids tends to be insufficient. That is, the two liquids flow in the axial direction, and depend on the phenomenon that heavy liquid moves outward and light liquid moves inward by a specific gravity difference along a plurality of longitudinal separation plates. In the case of solid-liquid separation, as described above, the solid is pressed against the inner wall to enable separation, but in the case of liquid-liquid separation, effective separation cannot be achieved.

Thus, in the conventional centrifugal liquid-liquid separator, satisfactory results cannot be obtained, and various waste liquids are discarded without being sufficiently separated.
An object of the present invention is to provide a centrifugal liquid-liquid separation apparatus that can achieve liquid-liquid separation efficiently with a relatively simple structure in view of the problems of the prior art.

  The device according to the present invention is a centrifugal liquid-liquid separator in which a rotating body is rotatably mounted in a cylindrical outer cylinder, and the rotating body has a plurality of vertical through holes in a peripheral portion and the outer A centrifugal liquid-liquid separation device, characterized in that it is an elastic body having a smaller diameter than a cylinder, and its peripheral part is in close contact with the inner surface of the outer cylinder by the rotation of the rotating body. A heavy liquid take-out pipe formed by being bent in the circumferential direction next to the top, and a light liquid take-out pipe formed by being bent in the circumferential direction from the upper surface to the lower side of the heavy liquid take-out pipe. A rotating body that has a plurality of through-holes and is an elastic body having a smaller diameter than the outer cylinder is rotated at a high speed by a centrifugal liquid-liquid separation device mounted in the cylindrical outer cylinder, and the peripheral portion of the rotating body is The outer cylinder is in close contact with the inner surface of the outer cylinder and divided into an upper chamber and a lower chamber , Supplying a stock solution that is a mixture of heavy liquid and light liquid to the upper chamber of the apparatus, and guiding the heavy liquid in the stock solution from the upper chamber to the lower chamber through the through-hole. The centrifugal liquid-liquid separation method is characterized in that the liquid is separated from the light liquid, the separated heavy liquid is taken out from the heavy liquid take-out pipe, and the light liquid is taken out from the light liquid take-out pipe.

The present invention will be described in detail below.
The present invention is a centrifugal separation apparatus and method for separating a mixed liquid of a plurality of liquids having a specific gravity difference (which may be a suspension by mixing a small amount of solid content) using the specific gravity difference. . The number of liquids is usually two, but may be three or more. In the case of three kinds, the liquid is separated into two kinds of mixed liquid and one kind of liquid.
The stock solution before centrifugation is not particularly limited as long as it is a mixed solution having a specific gravity difference, but various waste fluids (drains), for example, waste fluids during die casting of aluminum, release fluids from release agents, food waste water, use of nuclear power plants Used waste liquid, waste paint, waste ink, waste paint liquid, cleaning waste liquid of equipment using mineral oil, and cutting fluid. The separated liquid with a high specific gravity (hereinafter referred to as “heavy liquid”) and the liquid with a low specific gravity (hereinafter referred to as “light liquid”) are discarded as they are or are recycled.

  As a conventional type, a rotating body is mounted in a cylindrical outer cylinder, the rotating body is rotated together with the outer cylinder, a solid-liquid mixture is supplied onto the rotating body, and the centrifugal separation is performed to separate liquid and solid by centrifugation. There is a device. However, in this apparatus, since both the outer cylinder and the rotating body are metal rigid bodies, there is a problem in that the contact surface is not sufficiently adhered, vibration is generated, and unevenness occurs in the rotation of the rotating body.

In the present invention, in order to solve this problem, it is desirable that the rotating body is made of an elastic body such as rubber or resin and has oil resistance and chemical resistance. The shape of the rotating body is a cylindrical shape whose diameter is slightly smaller than the inner diameter of the outer cylinder, and a plurality of through holes in the vertical direction are formed in the peripheral edge portion. The plurality of through holes are preferably formed at equal intervals so that smooth rotation can be achieved when the rotating body rotates. The actual diameter of the rotating body is preferably 150 to 300 mm and more preferably 200 to 250 mm in consideration of the adhesion force with the inner surface of the outer cylinder to be described later.
The outer cylinder is a cylindrical shape having a slightly larger inner diameter than the rotating body, and a material that does not deform or hardly deforms such as metal or hard resin is used. The gap between the periphery of the rotating body and the inner edge of the outer cylinder when the rotating body is stopped is preferably 5 to 8 mm, but is not limited thereto.

When both are rotated at a high speed while the rotating body is positioned in the outer cylinder, a centrifugal force acts on the rotating body to expand in the circumferential direction. Due to this expansion, the peripheral surface of the rotating body comes into contact with the inner wall of the outer cylinder. Since this contact is a contact between the rotating body, which is an elastic body, and a rigid outer cylinder, the rotating body is freely deformed, that is, the rotating body is deformed corresponding to the irregularities on the surface of the outer cylinder, and both are In close contact. This contact force does not cause vibration in the rotating rotating body, and enables stable rotation and therefore stable liquid-liquid separation.
Thereby, the inside of the outer cylinder is separated into an upper chamber above the rotating body and a lower chamber below the rotating body, and both chambers communicate with each other through the plurality of through holes.

When liquid mixtures having different specific gravity differences are supplied to the upper chamber while maintaining this high speed rotation, the heavy liquid in the liquid mixture moves in the circumferential direction due to strong centrifugal force, and at least a part of the liquid mixture is outside the outer chamber. Contact the inner surface of the tube. This heavy liquid reaches the lower chamber of the outer cylinder through the through hole of the rotating body.
The separated heavy liquid may remain in the lower chamber when the amount of the mixed liquid is small and may be taken out after the end of the rotation, but the mixed liquid volume is larger than the capacity of the centrifugal liquid-liquid separator. In some cases, it is preferable to take out the apparatus while rotating at high speed. For example, if a take-out pipe communicating with the outside of the apparatus is formed on the bottom surface of the rotating body, the separated heavy liquid having an increased volume can be forcibly taken out of the apparatus from the take-out pipe.

  On the other hand, the light liquid in the mixed liquid does not receive the centrifugal force as much as the heavy liquid, and therefore stays near the center of the upper surface of the rotating body. If the amount of the mixed liquid is small, it may be retained and removed after separation from the heavy liquid, but if the amount of the mixed liquid is larger than the capacity of the centrifugal liquid-liquid separator, It is preferable to take it out of the apparatus. For example, if a take-out pipe communicating with the outside of the apparatus is formed on the upper surface of the rotating body, the separated light liquid can be taken out of the apparatus from the take-out pipe.

  After the heavy liquid and the light liquid are sufficiently separated, the rotation of the rotating body and the outer cylinder is stopped. As a result, the rotating body, which is an elastic body, returns to its original state from the expanded state, and a gap is formed between the outer cylinder and the rotating body. Therefore, if a light liquid exists on the upper surface of the rotating body when the rotation is stopped or the rotation becomes weak, the light liquid flows down to the lower chamber through the gap and is mixed with the separated heavy liquid. Therefore, when stopping the rotation, it is desirable to take out at least one of light liquid and heavy liquid from the apparatus. For example, after all of the light liquid has been separated and removed, the heavy liquid remains in the lower chamber, but an openable / closable outlet is provided on the bottom surface of the outer cylinder, and when this outlet is opened after rotation stops, only the separated heavy liquid is removed. Can be taken out.

  In normal centrifugal liquid-liquid separation, a small amount of solid content may be mixed in the stock solution in addition to the liquid, and these solid content may be removed from the upper surface of the rotating body, the inner surface of the through hole, the side surface or the bottom surface of the outer cylinder after liquid-liquid separation. In many cases, it adheres firmly. In the centrifugal liquid-liquid separation device of the present invention, since the rotating body is separated from the outer cylinder after the high-speed rotation is stopped, the solid content can be easily removed and washing can be completed simply by flowing a water flow to the upper chamber side.

  The present invention is configured as described above, and by using a rotating body that is an elastic body, centrifugal liquid-liquid separation can be performed in a state where the rotating body and the outer cylinder are in close contact with each other. When the rotator is rotated at a high speed, the rotator expands and the periphery of the rotator is automatically strongly pressed against the inner surface of the outer cylinder, deforms according to the irregularities on the surface, and adheres without gaps except for the through holes. As a result, the rotating body and the outer cylinder integrally rotate at high speed without causing vibration or the like, so that heavy liquid and light liquid can be separated smoothly. In addition, it is not necessary to support the rotating body separately, and the apparatus can be configured with only the outer cylinder and the rotating body, so that the structure can be greatly simplified as compared with the conventional apparatus.

Next, an example of the centrifugal liquid-liquid separation device according to the present invention will be described with reference to the accompanying drawings, but this does not limit the present invention.
FIG. 1 is a partially broken perspective view illustrating a main part of a centrifugal liquid-liquid separation device according to the present invention, and FIG. 2 is a perspective view and a longitudinal sectional view showing a series of operating states of the centrifugal liquid-liquid separation device. 2A shows the situation before the rotation of the rotating body, FIG. 2B shows the situation where the rotating body is rotating, FIG. 2C shows the situation where the stock solution is supplied to the rotating body that is constantly rotating, and FIG. It is a perspective view which shows the condition which stopped rotation of the body, respectively. 2A-1 is a longitudinal sectional view taken along line A-1 in FIG. 2A, FIG. 2B-1 is a longitudinal sectional view taken along line B-1 in FIG. 2B, and FIG. 2C-1 is a longitudinal sectional view taken along line C-1 in FIG. 2C-2 is a longitudinal sectional view taken along line C-2 in FIG. 2C, FIG. 2D-1 is a longitudinal sectional view taken along line D-1 in FIG. 2D, and FIG. 3 is a longitudinal sectional view showing another example of a centrifugal liquid-liquid separator. FIG.

  A short cylindrical rotary body 2 (shown by a solid line in FIG. 1) is located in a longitudinal long cylindrical outer cylinder 1 having a bottom surface and a top plate, and is shown in FIGS. As shown in FIG. 1, the rotating body 2 is separated from the inner wall of the outer cylinder 1 by a distance “d” when stationary. A liquid discharge port 4 is formed at the center of the bottom surface 3 of the outer cylinder 1, and a stock solution supply pipe 7 having a dispersion plate 6 attached to the lower end is provided at the center of the top plate 5. In the example shown in the figure, the central axes of the outer cylinder 1 and the rotating body 2 are made to coincide with each other.

The rotating body 2 is made of an elastic body such as rubber or resin, and a total of four through-holes 8 are formed in the vertical direction at the peripheral edge of the rotating body 2 at equal intervals.
Two light liquid take-out pipes 9 formed on the slightly outer side of the center of the upper surface of the rotating body 2 and then bent in the circumferential direction are further slightly outside the center of the lower surface of the rotating body 2. Are respectively formed with heavy liquid take-out pipes 10 which are formed by being bent upward and then circumferentially. The same number of light liquid outlets 11 and heavy liquid outlets 12 are formed in the outer cylinders 1 corresponding to the light liquid outlet pipe 9 and the heavy liquid outlet pipe 10, respectively.

  When a rotational force is applied to the outer cylinder 1 and the rotating body 2 from the stopped state of FIGS. 1, 2 </ b> A, and A- 1, the rotating body 2 that is an elastic body starts to expand and rotates at a high speed. As described above, the periphery of the rotating body 2 is in close contact with the inner wall of the outer cylinder 1 (FIGS. 2B and 2B-1; FIGS. 2B to D omit the bottom surface and the top plate of the outer cylinder), and the light liquid take-out pipe 9 and The outlet side of the heavy liquid outlet pipe 10 is aligned with the light liquid outlet 11 and the heavy liquid outlet 12 of the outer cylinder 1, respectively. Thus, the inside of the outer cylinder 1 is clearly divided into an upper chamber 13 and a lower chamber 14 below the rotating body.

  If the stock solution 15 that is a mixture of light and heavy liquids is supplied from the stock solution supply pipe 7 while maintaining this high speed, the stock solution 15 collides with the dispersion plate 6 as shown in FIGS. C-1 and C-2. And then scatter in the circumferential direction. The light liquid and the heavy liquid in the stock solution 15 are centrifuged by the specific gravity difference, the light liquid 16 collects near the center of the upper surface of the rotating body 2, and the heavy liquid 17 moves in the circumferential direction and contacts the inner surface of the outer cylinder 1. . The light liquid 16 moves in the circumferential direction through the light liquid take-out pipe 9 formed near the center of the upper surface and is taken out from the light liquid take-out port 11. The heavy liquid 17 that has contacted the inner surface of the outer cylinder moves downward through the through-hole 8 on the periphery of the rotating body 2 and reaches the lower chamber 14. The heavy liquid 17 in the lower chamber 14 is moved inward of the lower chamber 14 by the subsequent heavy liquid 17 and is taken out of the outer cylinder 1 from the heavy liquid outlet pipe 10.

After the predetermined amount of heavy liquid 17 and light liquid 16 are thus centrifuged and only the heavy liquid is present in the apparatus, the rotation of the outer cylinder 1 and the rotating body 2 is stopped. As a result, the expanded rotating body 2 contracts to its original size, returns to the state of FIG. 2D, which is the same as FIG. 2A, and the heavy liquid 17 remaining in the lower chamber 14 is taken out from the liquid discharge port 4.
When the cleaning liquid 18 is supplied from the stock solution supply pipe 7 in this state, the cleaning liquid 18 cleans the inside of the upper chamber 13 including the upper surface of the rotating body 2 and then cleans both through the gap between the outer cylinder 1 and the rotating body 2. However, after reaching the lower chamber 14 and washing the lower chamber 14, it is taken out from the liquid discharge port 4. In the state of FIG. 2D, since the gap between the outer cylinder 1 and the rotating body 2 is generated, the cleaning liquid moves from the upper chamber 13 to the lower chamber 14 without receiving a large resistance, thereby enabling smooth cleaning.

When the outer cylinder 1 and the rotating body 2 start to rotate, the outlet side of the light liquid extraction pipe 9 and the light liquid outlet 11, and the outlet side of the heavy liquid outlet pipe 10 and the heavy liquid outlet 12 are aligned. Can be difficult.
In this case, for example, as shown in FIG. 3, one end of a cylindrical tube 19 made of metal or the like is inserted into the outlet side of the light liquid extraction tube 9 of the rotating body 2 before rotation, and the other end of the outer tube 1. The light liquid outlet 11 may be engaged. Even if the rotating body 2 rotates and expands, the cylindrical tube 19 engages with the light liquid outlet 11, and a light liquid take-out pipe can be secured. The same applies to the outlet side of the heavy liquid outlet tube 10 and the heavy liquid outlet 12.

The partially broken perspective view which illustrates the principal part of the centrifugal liquid-liquid separator which concerns on this invention. The perspective view and longitudinal cross-sectional view which show a series of operation | movement situations of the centrifugal liquid-liquid separator of FIG. The longitudinal cross-sectional view which illustrates the aspect of another centrifugal liquid-liquid separator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer cylinder 2 Rotating body 8 Through-hole 9 Light liquid extraction pipe 10 Heavy liquid extraction pipe 13 Upper chamber 14 Lower chamber 15 Stock solution 16 Light liquid 17 Heavy liquid 19 Cylindrical tube

Claims (5)

  In a centrifugal liquid-liquid separation device in which a rotating body is rotatably mounted in a cylindrical outer cylinder, the rotating body has a plurality of vertical through holes in a peripheral portion and is smaller in elasticity than the outer cylinder. A centrifugal liquid-liquid separation device, characterized in that a peripheral portion thereof is in close contact with the inner surface of the outer cylinder by the rotation of the rotating body.   The centrifugal liquid-liquid separator according to claim 1, wherein the elastic body is rubber or resin.   The centrifugal liquid-liquid separator according to claim 1, further comprising a heavy liquid take-out pipe formed by being bent upward in the circumferential direction from the bottom of the rotating body.   The centrifugal liquid-liquid separator according to any one of claims 1 to 3, further comprising a light liquid take-out pipe formed by being bent downward from the upper surface of the rotating body and then circumferentially.   It has a heavy liquid take-out pipe formed by bending upward from the bottom and then circumferentially, and a light liquid take-out pipe formed by bending downward from the top and then circumferentially, and a peripheral edge. The rotary liquid-liquid separation device in which a rotating body, which has a plurality of through holes in the vertical direction in its part and is an elastic body having a smaller diameter than the outer cylinder, is mounted in a cylindrical outer cylinder, is rotated at a high speed to rotate the rotating body. The outer periphery of the body is brought into close contact with the inner surface of the outer cylinder to divide the outer cylinder into an upper chamber and a lower chamber, and a stock solution that is a mixture of heavy liquid and light liquid is supplied to the upper chamber of the apparatus, The heavy liquid in the stock solution is guided from the upper chamber to the lower chamber through the through hole to separate the heavy liquid from the light liquid, the separated heavy liquid is removed from the heavy liquid take-out pipe, and the light liquid is removed from the light liquid. A centrifugal liquid-liquid separation method, wherein the liquid is extracted from the liquid extraction pipe to the outside of the apparatus.

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