JP4333286B2 - Screw decanter centrifuge - Google Patents

Description

  The present invention relates to a centrifuge that separates a stock solution into a solid component and a liquid component using centrifugal force, and more particularly to a screw decanter centrifuge.

  As the centrifuge, there is a screw decanter type centrifuge equipped with an outer cylinder (outer cylinder bowl) that rotates in a predetermined direction and an inner cylinder that rotates in the same direction as the outer cylinder in the outer cylinder (for example, Patent Document 1).

In the screw decanter type centrifuge, the stock solution is separated into solid and liquid according to the specific gravity difference on the inner peripheral surface of the rotating outer cylinder, and the separated liquid and solid matter are recovered. The solid-liquid matter that has settled on the inner peripheral surface of the outer cylinder is moved in the axial direction of the inner cylinder by a screw plate disposed on the outer peripheral surface of the inner cylinder, and then discharged and collected from the inside of the outer cylinder. Is done.
Japanese Patent Laid-Open No. 06-063450 (FIG. 1)

  By the way, in the screw decanter type centrifuge, the solid matter discharged from the inside of the outer cylinder adheres to and accumulates on the inner wall of the casing, which may cause problems in the operation of the outer cylinder. That is, the solid matter deposited on the inner wall of the casing becomes large, which may come into contact with the outer cylinder and hinder the rotation of the outer cylinder.

  This invention is made | formed in view of the said situation, and it aims at providing the screw decanter type | mold centrifuge which can prevent generation | occurrence | production of the malfunction by the deposit of the solid substance discharged | emitted from the outer cylinder.

  In order to achieve the above object, the present invention provides a screw including an outer cylinder that rotates in a predetermined direction, an inner cylinder that rotates in the same direction as the outer cylinder in the outer cylinder, and a casing that covers the outer cylinder. In the decanter-type centrifuge, the outer body is provided with a discharge port for discharging the centrifuged solid material, and the casing is provided with a discharge port for the solid material at a position facing the discharge port. A deposition preventing member for preventing deposition is provided.

  In this screw decanter type centrifuge, the accumulation prevention member prevents the solid matter from being deposited on the casing, so that the occurrence of malfunction of the outer cylinder due to the solid matter accumulation is prevented.

  In the screw decanter centrifuge described above, it is preferable that the accumulation preventing member includes a surface disposed obliquely with respect to the discharge direction of the solid matter from the discharge port. Thereby, the moving direction of the solid object is changed by the oblique surface, and the solid object is prevented from being deposited.

  In this case, for example, the deposition preventing member may include an angle member arranged with a ridge line at a position facing the discharge port, and may be disposed extending in the circumferential direction of the outer body. Thereby, since a solid thing moves separately on both sides of the ridgeline of an angle member, accumulation of a solid substance is prevented.

  As described above, according to the screw decanter type centrifuge of the present invention, the accumulation prevention member prevents the solid matter from being accumulated in the casing, thereby preventing the occurrence of problems due to the accumulation of the solid matter discharged from the outer body. can do.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is an overall configuration diagram schematically showing an embodiment of a screw decanter centrifuge according to the present invention. The centrifuge 10 of this example is a three-phase separation type that separates a slurry-like stock solution into three phases of light liquid, heavy liquid, and solid according to specific gravity. The present invention is not limited to the three-phase separation type, and is preferably applied to, for example, a two-phase separation type centrifuge.
First, the overall configuration and basic operation of the centrifuge 10 will be described.

  The centrifuge 10 mainly includes a cylindrical outer shell bowl 11 that is rotatably arranged, and an inner drum 12 that is rotatably arranged coaxially with the outer shell bowl 11 inside the outer shell bowl 11. It is configured. The outer shell bowl 11 and the inner shell 12 are each connected to a drive device (not shown) and are rotated in the same direction at a predetermined rotation speed (for example, 2000 to 6000 rpm). A speed difference is provided between the two cylinders 11 and 12, and the number of rotations per unit time of the inner cylinder 12 is determined to be slightly less (or more) than that of the outer cylinder bowl 11. Yes. Reference numerals 15 and 16 are bearings for rotatably supporting the outer shell bowl 11 and the inner shell 12, 17 is a gear box for determining a speed difference between the outer shell bowl 11 and the inner shell 12, 18 is a support frame, and 19 is an outer frame. A casing that covers the body bowl 11.

  Inside the inner cylinder 12 is provided a stock solution supply chamber 20 which is a space to which a stock solution to be centrifuged is supplied. The undiluted solution is supplied to the undiluted solution supply chamber 20 through a undiluted solution supply pipe 21 disposed in the inner cylinder 12 in an inserted state, and the inner cylinder 12 and the outer torso bowl 11 through a discharge port 41 provided in the inner cylinder 12. Released between and.

  During operation of the apparatus, the stock solution sent between the inner cylinder 12 and the outer cylinder bowl 11 stays on the inner peripheral surface of the outer cylinder bowl 11 due to centrifugal force, and the light liquid and the heavy liquid according to the specific gravity difference. It separates into three phases: liquid and solid (cake). The separated light liquid and heavy liquid are respectively discharged from the inside of the outer body bowl 11 through the discharge ports 30 and 31 provided at one end of the outer body bowl 11, and the light liquid outlet 32 provided in the casing 19 and Each is sent to the heavy liquid outlet 33.

  On the other hand, the separated solid substance (cake) is sent to the other end side of the outer shell bowl 11 which is the opposite side to the discharge side of the light liquid and the heavy liquid. That is, a spiral screw plate 13 is disposed on the outer peripheral surface of the inner cylinder 12, and solid matter staying on the inner peripheral surface of the outer cylinder bowl 11 is accompanied by the rotation of the inner cylinder 12. It is pushed by the screw plate 13 and moves to the other end side of the outer body bowl 11 along the axial direction of the inner body 12. On the other end side of the outer shell bowl 11, the solid material is conveyed by the screw plate 13 according to the speed difference between the outer shell bowl 11 and the inner shell 12 and dehydrated at the conical portion of the outer shell bowl 11.

  On the peripheral surface on the other end side of the outer shell bowl 11, a discharge port 25 for discharging solid matter in the outer shell bowl 11 is provided. The solid material carried to the other end side of the outer shell bowl 11 is discharged from the inside of the outer shell bowl 11 into the casing 19 through the discharge port 25. The solid matter discharged into the casing 19 is sent to a solid outlet 34 provided in the casing 19 by gravity. A reference numeral 55 shown in FIG. 1 is a deposition preventing member for preventing the deposition of a solid substance on the inner wall of the casing 19, which will be described later.

  Thus, in the centrifuge 10, the stock solution is separated into light liquid, heavy liquid, and solid matter. They are recovered through the light liquid outlet 32, the heavy liquid outlet 33, and the solid outlet 34, respectively. In the above centrifugation, an aggregating agent is added to the stock solution as necessary. By adding the flocculant, it is possible to improve the separation performance and improve the recovery rate of the solid matter.

  Next, the deposition preventing member 55 that is a characteristic part of the centrifugal separator 10 will be described. FIG. 2 is a view showing the vicinity of the discharge port 25 of the outer body bowl 11 in the centrifugal separator 10, and FIG. 3 is a view showing the arrangement state of the deposition preventing member 55.

  As shown in FIGS. 2 and 3, a plurality of discharge ports 25 that are separated from each other in the circumferential direction are provided on the peripheral surface of the outer shell bowl 11. On the inner wall of the casing 19, a deposition preventing member 55 is disposed at a position facing the discharge port 25, that is, a position on an extended line extending radially outward from the axial center of the outer shell bowl 11 through the discharge port 25. ing.

  The deposition preventing member 55 includes an angle member 56 that is arranged with a position facing the solid material discharge port 25 as a ridge line, and a support member 57 that supports the angle member 56 with respect to the inner wall of the casing 19. Yes. The angle member 56 is disposed to extend over the circumferential direction of the outer body bowl 11 so as to surround the outer body bowl 11. The two flat portions 56 a and 56 b that form the ridge line of the angle member 56 are respectively arranged obliquely with respect to the discharge direction of the solid material from the discharge port 25.

Next, the operation of the deposition preventing member 55 will be described.
As described above, when the apparatus is in operation, the centrifuged solid matter is discharged from the inside of the outer shell bowl 11 into the casing 19 through the discharge port 25. The discharged solid matter is scattered in the radial direction of the outer shell bowl 11 through the discharge port 25 and moves toward the inner wall of the casing 19.

  A deposition preventing member 55 is disposed at a position opposite to the discharge port 25, and the solid matter discharged from the discharge port 25 collides with the angle member 56 of the deposition prevention member 55, and both sides of the ridge line of the angle member 56. Move to separate. At this time, since the angle member 56 is formed extending along the circumferential direction of the outer shell bowl 11, the solid matter discharged from the outer shell bowl 11 reliably collides with the deposition preventing member 55. Further, since the flat portions 56a and 56b of the angle member 56 are arranged obliquely with respect to the discharge direction of the solid matter from the discharge port 25, the solid matter moves along the flat portions 56a and 56b. The width in the moving direction is spread and dispersed.

  Due to the dispersion of the solid matter, most of them fall by gravity without colliding with the inner wall of the casing 19. Further, even when a solid object collides with the inner wall of the casing 19, since the energy at the time of the collision is small, adhesion of the solid object on the inner wall of the casing 19 is suppressed, and accumulation there is prevented. . As a result, most of the solid material falls by gravity without being deposited on the inner wall of the casing 19. And the fallen solid object is collect | recovered via the solid outlet 34 provided in the lower part of the casing 19. FIG.

  As described above, in the centrifuge 10 of this example, the accumulation prevention member 55 prevents the solid matter from being deposited on the inner wall of the casing 19. Therefore, the malfunction of the outer shell bowl 11 due to the accumulation of solid matter discharged from the outer shell bowl 11 is prevented.

  The shape of the deposition preventing member is not limited to the above. For example, it is good also as a structure which can adjust the distance of a deposition prevention member and an outer shell bowl.

  As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

1 is an overall configuration diagram schematically showing an embodiment of a screw decanter centrifuge according to the present invention. It is a figure which shows the discharge port vicinity of an outer trunk bowl. It is a figure which shows the arrangement | positioning state of the deposition prevention member.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Centrifuge, 11 ... Outer body bowl (outer body), 12 ... Inner body, 13 ... Screw plate, 19 ... Casing, 20 ... Stock solution supply chamber, 21 ... Stock solution supply pipe, 25 ... Discharge port, 41 ... Release Outlet, 55: Deposition prevention member, 56: Angle member, 56a, 56b: Plane portion, 57: Support member.

Claims (2)

In a screw decanter centrifuge comprising an outer cylinder rotating in a predetermined direction, an inner cylinder rotating in the same direction as the outer cylinder in the outer cylinder, and a casing covering the outer cylinder,
The outer body is provided with a discharge port for discharging the centrifuged solid matter,
The casing is provided with a deposition preventing member for preventing deposition of the solid matter at a position facing the discharge port .
The screw decanter type centrifugal separator , wherein the accumulation preventing member includes a surface that is obliquely arranged so that the solid matter is dispersed with respect to a discharge direction of the solid matter from the discharge port . 2. The accumulation preventing member includes an angle member arranged with a ridge line at a position facing the discharge port, and is disposed to extend in a circumferential direction of the outer body. Screw decanter centrifuge.

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