JPH10151369A - Centrifugal separation of multilayer mixture and screw decanter type centrifugal separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively and continuously separate a multilayer mixture containing an intermediate layer. SOLUTION: This device is provided with a rotary shell 1 and a screw conveyor 2 installed in the rotary shell 1. In this case, the rotary shell 1 is provided with a light liquid layer takeoff port 33 and a heavy liquid layer takeoff port 3, and an intermediate layer takeoff port 19 in one large diameter side end part thereof, and in the other small diameter side end part thereof respectively. And moreover, a partition member 9 is fitted through which the screw conveyor shell part 23 passes partly and which is installed fixed on the small diameter side from a raw liquid feeding port 42 installed toward the inner wall of the cylinder part of the rotary shell 1 and which is intended for preventing a light liquid layer 7 from flowing to the conical part 12 side of the rotary shell 1 over the installed point thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for separating a multilayer mixture comprising at least a heavy liquid layer, an intermediate layer and a light liquid layer,
And a device suitable for centrifuging the multilayer mixture.

[0002]

2. Description of the Related Art Conventionally, in order to remove an intermediate layer from a multilayer mixture consisting of a heavy liquid layer, an intermediate layer and a light liquid layer, a method of vacuum filtration using a filter aid such as celite or radiolite is generally employed. Had been On the other hand, it is known to separate a coal tar by using a three-layer separation screw decanter to remove water and sludge (solid matter) in the coal tar. In this case, water and coal tar are collected from the large-diameter outlet, and the sludge having the highest specific gravity is scraped off the inclined portion of the screw decanter by the screw conveyor and discharged from the small-diameter outlet.

[0003]

However, since vacuum filtration is usually performed in a batch system, it is not suitable for filtering a large amount of a multilayer mixture. In addition, the method of removing the intermediate layer by vacuum filtration is such that when the intermediate layer is sticky, for example, containing a tar-like substance, the filter aid is contaminated in a short time, and the sticky intermediate layer is efficiently removed from the multilayer mixture. Is difficult to remove.

On the other hand, when the three-layer separation screw decanter is used to separate a multilayer mixture composed of a heavy liquid layer, an intermediate layer and a light liquid layer, particularly a multilayer mixture having a small amount of an intermediate layer, an intermediate layer having an intermediate specific gravity is obtained. However, there is a problem that the inclined portion of the screw decanter is not easily scraped up by the screw conveyor, so that it is difficult to be discharged to the outlet on the small diameter side, and the separation between the light and light layers and the intermediate layer becomes insufficient.

[0005]

Means for Solving the Problems The present inventor has made intensive studies to solve the above problems, and as a result, a screw decanter-type centrifugal separator, in which each of the large-diameter ends of the rotary drum of the screw decanter has a screw, A light liquid layer take-out port and a heavy liquid layer take-out port provided on the body side of the conveyor and the inner wall side of the rotary body, an intermediate layer take-out port provided on the small diameter end side of the rotary body, and a screw conveyor body. A centrifugal separator fixedly installed on the small-diameter side of the supply port of the multilayer mixture and provided with a partition member for preventing the light liquid layer from flowing toward the intermediate layer take-out port side from the installation point; The present inventors have found that the above-mentioned multilayer mixture can be efficiently separated by using the present invention, and completed the present invention.

That is, the present invention relates to a method for separating a multilayer mixture comprising a heavy liquid layer, an intermediate layer and a light liquid layer, wherein the mixture has a cylindrical shape with both ends open, and one opening is formed with a large diameter. At the same time, the inside of the opening is integrally formed with a cylindrical portion having a cylindrical shape, the other opening is formed with a small diameter, and the inside of the opening is integrally provided with a conical portion having a truncated cone shape, and the center of the opening is the cylindrical shape. A rotary drum having a virtual straight line generated along the longitudinal direction as a rotation axis, a screw conveyor disposed inside the rotary drum, and provided in close proximity to an inner wall of the rotary drum, and a trunk portion of the screw conveyor; A supply port that partially penetrates along the rotation axis and supplies the multilayer mixture toward the inner wall of the cylindrical portion of the rotary drum, and the large-diameter side end of the rotary drum on the drum side of the screw conveyor. Light liquid layer outlet provided in the Said rotation said at barrel end of the large diameter side, the rotary shell inner wall heavy liquid layer is provided on the side outlet,
An intermediate layer take-out port provided at the small-diameter side end of the rotary drum, and fixedly installed on a smaller-diameter side than the supply port of the screw conveyor body, and the light liquid layer, A centrifugal separation method for a multilayer mixture, comprising using a screw decanter-type centrifugal separator provided with a partition member for preventing flow to the conical portion side of the rotary drum.

Further, the present invention has a cylindrical shape with both ends open, one opening is formed in a large diameter, the inside of the opening is formed in a cylindrical shape, and the other opening is formed in a small diameter. A rotating drum having an opening inside integrally formed with a truncated cone-shaped conical portion, and a center of the opening having a virtual straight line generated along the longitudinal direction of the cylindrical shape as a rotation axis; And a screw conveyor provided in proximity to the inner wall of the rotary drum, and partially penetrating the body of the screw conveyor along the rotation axis and toward the cylindrical inner wall of the rotary drum. A supply port for supplying a multilayer mixture consisting of a heavy liquid layer, an intermediate layer, and a light liquid layer, and is uniformly arranged in the circumferential direction on the end side of the large diameter in the rotary drum,
A first outlet for collecting light liquid is provided coaxially with the rotation axis, and is uniformly arranged in the circumferential direction on the large-diameter end side of the rotary drum, and is coaxial with the rotation axis. A second take-out port for collecting heavy liquid, and evenly arranged in the circumferential direction on the small-diameter end side of the rotary drum, and provided coaxially with the rotation axis, A third outlet for collecting layers;
A partition member is provided radially from the body of the screw conveyor, and has a smaller diameter side than the supply port and is fixedly positioned on the cylindrical part side of the rotary body.
A screw decanter-type centrifugal separator characterized in that the radial distance between the outlet and the partition member from the rotation axis satisfies the following formula (I).

Γ ₁ <Γ ₂ <Γ ₃ <Γ ₄ (I) (where Γ ₁ is the distance to the first outlet, Γ ₂ is the third
Distance to the outlet, gamma ₃ is the maximum distance to the partition member, the gamma ₄ represents the distance to the second outlet. )

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The apparatus used in the present invention is described below.
This will be described with reference to FIG. This device is provided coaxially with the rotating drum 1 driven at a predetermined rotation speed via a belt 17 by an electric motor (not shown), and is rotated at a predetermined speed by a speed reducer 22. This is a centrifugal separator constituted by a screw conveyor 2 driven.

The rotating drum 1 is formed in a penetrating cylindrical shape, a cylindrical portion 13 having an opening end (on the left side in the figure) having a large diameter and at least the inside of the opening having a cylindrical shape (on the right side in the figure).
The opening end has a smaller diameter than this, and at least the inside of the opening is integrally provided with a conical portion 14 having a truncated cone shape. The conical portion 14 is formed in the opening so as to gradually decrease in diameter toward the outer end corresponding to the right side of the figure, and its inclination angle is set within a range of 5 ° to 30 ° with respect to the horizontal line of the figure. . A ring-shaped side wall 18 having a predetermined radius dimension is provided at an open end of the conical portion 14 so as to close the open end. The side wall 18 has a cylindrical cylindrical shaft 15 provided coaxially therewith. The side wall 18 is provided with a plurality of intermediate layer take-out ports 19 uniformly arranged in the circumferential direction of the conical portion 14. This can be achieved by, for example, providing a hollow portion further concentrically on the side wall 18. can get.

On the other hand, at the open end of the cylindrical portion 13, a heavy liquid layer outlet 3 and a light liquid layer outlet 33 are provided. The heavy liquid layer outlet 3 can be obtained, for example, by providing a side wall at the opening end of the cylindrical portion 13 and providing a hollow portion 35 concentrically therewith, similarly to the intermediate layer outlet 19.
The heavy liquid layer 8 can be recovered by overflowing from the heavy liquid layer outlet 3. (See FIG. 3) Further, the light liquid layer take-out port 33 is, for example, a large diameter side (left side in the figure) from the disk-shaped partition member 9 fixed perpendicular to the body 23 of the screw conveyor 2. In the light liquid layer 7, the light liquid layer 7 flowing out of the hole 34 (see FIG. 3) near the rotation axis at the opening end of the cylindrical portion 13 is once received by a discharge tank (not shown), and then siphoned. It is possible to adopt a configuration in which the outside of the centrifugal separator is collected by a known means such as a tube.

The light liquid layer 7 and the heavy liquid layer 8 can be collected by a well-known variable impeller in addition to the siphon tube and the overflow as described above. Further, as shown in the figure, the partition member 9 is
Is provided so as to partially cross the spiral surface of the transfer section 21 (the lower side of the figure is the corresponding section). Cylindrical shaft 15
A pair of bearings 51 and 52 are externally fitted on both sides of the rotating body 1, whereby the rotating body 1 is rotatably supported by the rotating axis 6. Then, a belt 17 is mounted via a pulley 16 provided on the right side of the cylindrical shaft 15, and the rotary drum 1 is driven to rotate in a predetermined direction in the rotation direction indicated by the arrow in the figure.

The cylindrical body 23 of the screw conveyor 2
Are provided coaxially on the outer peripheral side of the cylindrical shaft 15 of the rotating drum 1, and the body 23 is indirectly connected to the bearing 51 via the cylindrical shaft 15,
The bearing is supported by 52 and is driven to rotate by the speed reducer 22 in the direction of the arrow in the figure. The rotation speed difference between the rotary drum 1 and the screw conveyor 2 is preferably 5 r. p.
m to 200r. p. m.

The screw conveyor 2 is provided with a spiral conveying section 21 on the outer periphery of a body section 23, and the outer peripheral edges 24, 24... Of the conveying section 21 are close to the inner walls 11, 12 of the rotating cylinder 1. It is arranged to be. Then, the screw conveyor 2 is driven to rotate in a predetermined direction in the figure. In FIG. 1, the partition member 9 is fixed to a disk shape perpendicular to the body of the screw conveyor 2, but, for example, as shown in FIG. Conical partition member 99 fixed in a conical shape to a part of the screw conveyor body 23 between the spiral portions to be formed.
It may be.

The partition member 99 is attached to the large-diameter side (left side in the figure) adjacent to the supply port 42, similarly to the disk-shaped partition member 9. In the illustrated example, the spiral pitches of the transport unit 21 are provided uniformly, but, for example, the light liquid layer outlet 33 and the heavy liquid layer outlet 3 of the cylindrical unit 13 have a small pitch, and the side wall of the conical unit 14 has a small pitch. The 18 side may have a large pitch.

A supply line 4 is provided for supplying the multilayer mixture to be centrifuged into the rotary drum 1.
Is provided inside the cylindrical shaft 15 so as to partially penetrate along the rotation axis 6. Internal line 1
The end 42 of the nozzle 4 is open to serve as a supply port for the multilayer mixture.
The supply port 42 is provided so that the multilayer mixture is discharged toward the inner wall 11 of the rotating drum 1.

The intermediate layer 5 includes a partition member 9 and a rotating drum inner wall 1.
It flows preferentially over the gap 1 and is drawn out of the centrifugal separator from the intermediate layer outlet 19. On the other hand, the light liquid is suppressed by the partition member 9 from flowing toward the inclined rotary drum cone 14. As shown in FIG.
The depth a (cm) of the intermediate layer 5, the depth b (cm) of the light liquid layer 7, and the height of the intermediate layer take-out port 19, which are larger in diameter than the partition member 9 or the partition member 99 fixed to the body portion of c (c
m), if the height d (cm) of the heavy liquid layer 8 is the same on the large diameter side and the small diameter side of the partition member 9 or 99, the light liquid layer 7
Is selected so as not to be located closer to the inner wall side of the rotary drum 1 than the lowermost part of the partition member 9 or 99, and when the specific gravity of the intermediate layer 5 and the specific gravity of the light liquid layer 7 are respectively ρa and ρb, the above c (c
m) is approximately calculated by the following equation (II) c = (ρb / ρa) × b + a + d (II) when the depth of these liquid layers is sufficiently smaller than the radius of the rotating drum 1. That is, so as to obtain the value obtained by this equation,
The height c of the intermediate layer outlet 19 may be set.

When the light liquid layer 7 is collected by, for example, a variable impeller, the diameter of the impeller is reduced (ie, the diameter of the impeller is reduced).
Reduce the amount recovered per unit time and increase the amount of stagnation in the centrifugal separator), and the intermediate layer falls down to the inner wall of the rotating drum,
It flows from the lower part of the partition member 9 to the small diameter side, and the intermediate layer 5 is easily discharged from the intermediate layer outlet 19. (See FIG. 4) At this time, the height of the light liquid layer outlet 33 from the rotary drum inner wall 11 on the large diameter side is (b + a + d), and the height of the heavy liquid layer outlet 3 from the rotary drum inner wall 11 is also d
On the other hand, the height of the intermediate layer outlet 19 on the small diameter side is c
The height of the lower part of the partition member 9 on the large diameter side from the inner wall 11 of the rotary drum is at a position intermediate between c and d.

[0019]

According to the present invention, the radial distances from the rotation axis of the partition member fixedly provided at a specific position and the first, second and third liquid layer outlets are respectively determined. By the provision, even in the case of a multilayer mixture in which the amount of the intermediate layer having an intermediate specific gravity is relatively small, the intermediate layer is easily discharged to the small-diameter outlet, and therefore, the light liquid, the intermediate layer, and the heavy liquid Can be continuously and efficiently separated.

[0020]

Next, the present invention will be described more specifically with reference to examples. The present invention is not limited by this embodiment. Example 1 A mixture consisting of an aqueous layer, an o-dichlorobenzene layer containing valuables, and a tar-like intermediate liquid layer was separated by the centrifugal separator shown in FIG. 1 or FIG.

The specific gravity of the aqueous layer is 1, and the specific gravity of the intermediate liquid layer is 1.0.
5. The specific gravity of the dichlorobenzene layer was 1.3. or,
The centrifugal separator was operated so that the centrifugal force was 800 G (g). During operation, the trunk 2 of the screw conveyor 2
On the larger diameter side than the disc-shaped partition member 9 or the conical-plate-shaped partition member 99 attached to 3, the lower layer dichlorobenzene has a depth d of about 17 cm and the intermediate liquid layer has a depth a of 0.
The removal amount of the aqueous layer and the dichlorobenzene layer was adjusted using a siphon tube at the outlet provided at the large-diameter end so that the depth of the aqueous layer was 5 cm and the depth b of the aqueous layer was 13 cm. The height c of the intermediate liquid layer outlet 19 was 30 cm.

The above mixture was continuously separated into an aqueous layer, a tar-like intermediate layer and a dichlorobenzene layer, and no adhesion or residue of the tar-like intermediate layer was observed in the centrifugal separator. As described above, in the present invention, by providing the partition member 9 or 99 and the intermediate liquid layer outlet 19 at specific positions, even a three-liquid layer mixture containing an adhesive tar having a small specific gravity difference from the light liquid layer can be obtained. Can be separated very easily.

[Brief description of the drawings]

FIG. 1 is a sectional view of a centrifugal separator according to the present invention.

FIG. 2 is a sectional view of another centrifugal separator according to the present invention.

FIG. 3 is an enlarged sectional view of a main part of FIG.

FIG. 4 is a diagram illustrating a separated state of each liquid layer in the apparatus used in the present invention.

[Explanation of symbols]

1. Rotary drum, 2. Screw conveyor, 3. Heavy liquid layer take-out port 4. Supply pipeline, 5. Middle layer, 6. Rotation axis, 7.
· Light liquid layer 8 · · Heavy liquid layer 9 · · · Disc-shaped partition member 11 and 12
..Rotating drum inner wall 13.Rotating drum cylindrical part, 14.Rotating drum cone part, 15.
・ Cylindrical shaft 18 ・ ・ Conical part side wall, 19 ・ ・ Intermediate layer take-out port 21 ・ ・ Screw conveyer part, 22 ・ ・ Reducer 23 ・ ・ Screw conveyer body part 24 ・ ・ Outer peripheral part of screw conveyer part, 33 ・・
Light liquid layer take-out port 41 Internal passage of screw conveyor, 42 Supply ports 51 and 52 Bearing, 99 Conical plate-shaped partition member In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] 1. A method for separating a multilayer mixture comprising a heavy liquid layer, an intermediate layer, and a light liquid layer, wherein the mixture has a cylindrical shape with both ends open, one opening is formed with a large diameter, and the inside of the opening is formed. Are integrally provided with a cylindrical portion having a cylindrical shape and a conical portion having the other opening formed with a small diameter and a truncated cone inside the opening, and the center of the opening is formed along the longitudinal direction of the cylindrical shape. A rotating body having a virtual straight line generated as a rotation axis, a screw conveyor disposed inside the rotating body and provided in close proximity to an inner wall of the rotating body, and a body part of the screw conveyor being the rotation axis. A supply port that partially penetrates along and supplies the multilayer mixture toward the inner wall of the cylindrical portion in the rotating drum; and a large-diameter end portion of the rotating drum, which is provided on a drum portion side of a screw conveyor. The light liquid layer outlet and the rotation In the large diameter end portion, the heavy liquid layer take-out port provided on the inner wall side of the rotating drum, the intermediate layer take-out port provided at the small diameter side end portion of the rotary drum, and the screw conveyor body portion A screw decanter-type centrifugal centrifugal centrifuge, which is fixedly installed on the smaller diameter side than the supply port, and provided with a partition member for preventing the light liquid layer from flowing toward the conical portion side of the rotating drum from the installation point. A method for centrifuging a multilayer mixture, comprising using a separation device. 2. A cylindrical shape having both ends open, one opening having a large diameter and the inside of the opening having a cylindrical shape, and the other opening having a small diameter and the inside of the opening being formed. A rotating drum having a virtual straight line generated along the longitudinal direction of the cylindrical shape as a rotation axis, wherein the rotating drum is provided integrally with a truncated cone-shaped conical portion, and disposed inside the rotating drum. And a screw conveyor provided in proximity to the inner wall of the rotary drum, and a heavy liquid layer that partially penetrates the body of the screw conveyor along the rotation axis and faces the inner wall of the cylindrical portion of the rotary drum, A supply port for supplying a multilayer mixture composed of an intermediate layer and a light liquid layer, and the liquid liquid is provided evenly in the circumferential direction on the large-diameter end portion side of the rotary drum and provided coaxially with the rotation axis; A first outlet for collecting A second outlet for collecting heavy liquid, which is equally arranged in the circumferential direction at the end of the large diameter in the rolling drum and is provided coaxially with the rotation axis; and the small diameter in the rotating drum. And a third outlet for collecting an intermediate layer, which is provided coaxially with the rotation axis and is provided radially from the body of the screw conveyor, A partition member fixedly positioned on the cylindrical side of the rotary drum with a smaller diameter side than the supply port,
A screw decanter-type centrifugal separator characterized in that the radial distance between the outlet and the partition member from the rotation axis satisfies the following formula (I). Γ ₁ <Γ ₂ <Γ ₃ <Γ ₄ (I) (where Γ ₁ is the distance to the first outlet, Γ ₂ is the third
Distance to the outlet, gamma ₃ is the maximum distance to the partition member, the gamma ₄ represents the distance to the second outlet. )