JP2005111440A - Separation board-type centrifuge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seal means of a separation board-type centrifuge for surely preventing the flow of a liquid and mist, or the like by sealing the gap between a casing and a rotating shaft when the rotation is stopped. <P>SOLUTION: This separation board-type centrifuge is provided with a labyrinth seal which seals the gap between the casing and the rotating shaft, and an annular gas expansion sealing member which seals the gap between the casing and the rotating shaft and the passage section of the labyrinth seal by contracting when the body of revolution rotates so as to detach the rotating shaft which is driven to rotate from the labyrinth seal, and by expanding when the body of revolution stops rotating so as to seal the gap between the casing and the rotating shaft and the passage section of the labyrinth seal. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a centrifuge for performing solid-liquid separation or liquid-liquid separation of a liquid to be treated by centrifugal force, and more specifically, a rotating shaft of a separation plate type centrifuge in which a separation plate group is mounted in a rotating body. This relates to a part seal mechanism.

Solid-liquid separation operation or liquid-liquid separation that separates the liquid to be treated containing solids and the liquid to be treated in which two or more liquids having a specific gravity difference are mixed into a solid and a liquid or two or more liquids A centrifuge that separates the solid and liquid components by a high centrifugal force action of a rotating body that rotates at high speed is used for operations and the like. Also, among the centrifuges, a separation plate group in which separation plates are laminated in a rotating body is mounted, and fine particles in the liquid and a mixed liquid with a small specific gravity difference are efficiently separated using the large sedimentation area of the separation plate group. Can be used in many industrial fields such as food, medicine, biotechnology, etc. for cleaning and clarifying liquids to be treated and recovering valuable materials, especially for lubricating oil in ships. Many are used to clean and fuel oil.

The separation plate type centrifuge is composed of a rotating body having a rotating drum and a lid that covers the upper portion of the rotating drum and having a sludge discharge hole in the outer peripheral portion, and a truncated-cone-shaped thin plate mounted in the rotating member. A separation cylinder group formed by stacking a large number of separation plates in the axial direction of the rotating body, a valve cylinder for opening and closing the sludge discharge hole, and an upper end fastened to the lower end axial center of the rotating body, and rotated by a rotation drive means The structure is provided with a rotating shaft that rotates the rotating body by driving, a casing that covers the entire rotating body, and a frame that mounts and fixes the casing and covers the rotation driving means. In the above structure, the rotating shaft passes vertically through the fixed casing and the frame that supports the casing, and a gap is formed between the fixed casing and the rotating shaft. In order to secure the property and prevent the flow of liquid or mist, it is necessary to seal the gap between the casing and the rotating shaft.

One structure for sealing the gap is a mechanical seal.
The structure of the mechanical seal includes at least one rotary seal ring in which an O-ring is disposed on the upper and lower ends in a rigid connection with a rotary shaft in order to enhance the sealing performance. The structure is fixed to the rotating shaft by a non-rotating seal ring that is firmly and flexibly brought into close contact with a spring force and a non-rotating seal housing that surrounds the non-rotating seal ring. However, there is a gap between the rotary sealing ring, the non-rotating sealing ring, and the sealing housing, and heat and wear due to sliding between the rotary sealing ring and the non-rotating sealing ring in the gap. In order to prevent this, it is necessary to continuously supply a sealing liquid for the purpose of cooling, lubrication and improvement of the sealing performance. For this purpose, a liquid supply line, a drain line and a drain for leaking drainage are used for the sealing liquid. It is indispensable to install three lines of piping. As a result, the structure is complicated, and it takes time and labor for maintenance, and the equipment cost including the incidental device becomes extremely expensive. Furthermore, since the sealing liquid in the seal portion may come into contact with the processing liquid, there is a problem that there is a risk of contamination of the processing liquid.

In addition, labyrinth seals that have a simple structure and are inexpensive are often used as sealing means when the confidentiality inside the casing is not as high as that required by mechanical seals. The labyrinth seal has a fixed labyrinth member having a plurality of concentric annular grooves engaged on the casing side, and a concentric annular groove that is fitted in an annular groove of the fixed labyrinth member in a non-contact manner, and is engaged on the rotating shaft side. A narrow passage section bent with the labyrinth member is formed, and the liquid flowing from the gap between the casing and the rotating shaft is blocked by pressing the liquid that is about to flow in by centrifugal force against the circumferential inner surface of the passage section. To do.

As a centrifuge equipped with the labyrinth seal, an example in which it is attached to a decanter type centrifuge is described in Patent Document 1, and an example in which it is attached to a centrifugal filter is described in Patent Document 2.
JP-A-10-089491 JP 2000-042449 A

The problem to be solved is that in a separation plate type centrifugal separator, a mechanical part used as a sealing means for sealing a gap formed between the casing and the rotating shaft to prevent the flow of liquid, mist, etc. The seal provides confidentiality inside the casing, but the structure is complicated and maintenance such as replacement of parts is not easy, and the seal is expensive. On the other hand, the labyrinth seal is inexpensive, but has a passage portion. For this reason, when the rotation is stopped when centrifugal force does not work, confidentiality inside the casing such as a mechanical seal cannot be obtained.

The present invention comprises a rotating body and a lid that covers the upper part of the rotating body, a rotating body having a sludge discharge hole in the outer peripheral portion, and a separating plate made of a truncated conical thin plate mounted in the rotating body. A separation cylinder group formed in a stack in the axial direction of the rotator and a valve cylinder for opening and closing a sludge discharge hole, and an upper end thereof is fastened to a lower end axial center of the rotator, and is rotationally driven by a rotation driving means. A separating plate type centrifuge provided with a rotating shaft for rotating the rotating body, a casing for covering the entire rotating body, a frame for mounting and fixing the casing, and a frame for covering the rotation driving means The labyrinth seal that seals the gap between the casing and the rotating shaft, and contracts when the rotating body rotates to separate the rotating shaft and / or the labyrinth seal, and when the rotating body stops Inflating a separation plate type centrifuge, characterized in that a gap portion and / or cyclic gas expansion seal member for sealing the passage of the labyrinth seal between the rotary shaft and the casing.

Further, the annular gas expansion seal member of the separator-type centrifuge includes a support rod and a gas inlet / outlet projecting from the inner wall of the casing or the frame toward the outer wall of the labyrinth seal, and at the tip of the support rod It consists of the attached annular bag member made from heat-resistant rubber.

The gas expansion seal member is a structure that supplies an expansion working fluid such as air from the outside and seals the elastic surface such as rubber by pressurizing and inflating the seal surface, so that the structure is simple and easy to handle. It is. Further, since the expansion working fluid is not in direct contact with the centrifugal separation processing liquid, there is no contamination of the processing liquid. Furthermore, since the gas expansion seal member is not in contact with the rotating shaft when the centrifuge is in operation, the rotation speed is not lowered and the separation performance can be maintained.

  Since the annular bag member of the gas expansion seal member that seals the passage portion of the labyrinth seal is made of heat-resistant rubber, hermeticity can be obtained even under steam heating, so that steam sterilization (SIP) inside the casing is suitably performed. be able to.

Since the gas expansion seal member only needs to be provided with an auxiliary device that supplies only the gas for expansion, both the equipment cost and the operation cost can be made extremely low compared to the mechanical seal.

  The labyrinth seal and the labyrinth seal passage are closed for the purpose of sealing the gap formed between the casing and the rotating shaft of the separator plate centrifuge reliably and inexpensively to prevent the flow of liquid and mist. This is realized by configuring the sealing member to be a gas expansion sealing member.

  FIG. 1 is a cross-sectional view of a main part of a separation plate type centrifuge of the present invention, and FIG. 2 is an explanatory view of a rotating body of the separation plate type centrifuge. FIG. 3 is an explanatory diagram of the entire configuration of the separation plate type centrifugal separator.

DESCRIPTION OF SYMBOLS 1 is a rotary body, 2 is fastened to the lower end shaft center part of the rotary body 1, and the rotating shaft to which the rotation drive means 31 was connected, 3 is a casing which covers the whole rotary body, 5 is mounting and fixing a casing Then, a frame that covers the rotation driving means 31, 4 constitutes a lower end surface of the casing 3, a disk cover fixed to the frame 5, 6 a radial bearing of a rotary shaft located at the upper end in the frame, and 7 a radial bearing 6. A bearing case 8 to be held covers the upper surface of the radial bearing 6 and a bearing cover which forms a fixed labyrinth member 9a which is a part of a labyrinth seal 9 described later, and 9 is related to the rotating shaft 2 which forms a pair with the fixed labyrinth member 9a. A labyrinth seal 10 comprising a rotating labyrinth member 9b attached thereto, 10 is a water supply device for supplying operating water to the valve cylinder 1e, and controlling the opening and closing of the sludge discharge hole 1c, and 11 is a disk cover. 4 is a gap between the rotary shaft 2, 12 is an annular gas expansion seal member that seals the gap, and 13 is a support rod that is configured as a supply channel for supplying the working fluid of the gas expansion seal member 12. is there.

Hereinafter, an embodiment of the separation plate type centrifuge of the present invention will be described in more detail together with the operation.
Reference numeral 1 denotes a rotating body comprising a rotating drum 1a and a lid 1b covering the upper portion of the rotating drum 1a. The rotating plate 1 has a sludge discharge hole 1c on the outer peripheral portion, and a separating plate made of a truncated and truncated thin plate inside. A separation plate group 1d formed by laminating many in the axial direction of 1 and a valve cylinder 1e for opening and closing a sludge discharge hole 1c are mounted.

The rotating body 1 is fastened to the lower axis of the rotating body 1 and is rotated at a high speed by the rotating shaft 2 that is rotationally driven by the rotation driving means 31. The entire rotating body 1 is covered with a casing 3, and the casing 3 has an annular leg portion 4 a of the disc cover 4 and an engaging portion that protrudes in the horizontal direction from the lower end of the annular leg portion 4 a. It is placed and fixed on the upper end portion of the frame 5 that covers the rotation driving means 31 via.

The labyrinth seal 9 is a member that seals the gap 11 between the disc cover 4 and the rotary shaft 2 so that no liquid flows when the rotating body 1 rotates, and is a fixed labyrinth having an annular groove that is a part of the bearing cover 8. A narrow passage portion that is bent is formed by the member 9a and the rotating labyrinth member 9b attached to the rotating shaft 2 side having a concentric annular groove that is fitted in the annular groove of the fixed labyrinth member 9a in a non-contact manner.

The gas expansion seal member 12 is an inflatable annular bag member made of heat-resistant rubber provided at the tip of a support rod 13 that protrudes from the inner wall of the casing 3 or the frame 5 toward the outer wall of the labyrinth seal 9. When the body 1 rotates, the body 1 contracts and separates from the rotating shaft 2 and / or the labyrinth seal 9, and when the rotating body 1 stops, the body 1 is expanded by working fluid such as instrument air supplied through the support rod 13. Thus, the gap 11 between the disc cover 4 and the rotary shaft 2 and / or the passage portion of the labyrinth seal 9 is sealed.

The lower part of the rotating body 1 is provided with a valve cylinder 1e for opening / closing a sludge discharge hole 1c for discharging sludge accumulated in the rotating body 1, and supply of working water to the valve cylinder 1e to control the opening / closing of the sludge discharge hole 1c. A water supply device 10 is incorporated, and the supply of working water to the water supply device 10 is supplied via a working water supply channel provided in the disc cover 4.

The labyrinth seal 9 is located between the disc cover 4 and the radial bearing 6 and prevents the processing liquid mist inside the casing 3 from entering the lubricating oil inside the frame 5 and also the lubricating oil mist inside the frame 5. Is a sealing means provided to prevent the liquid from flowing into the casing 3, and the liquid to be introduced by centrifugal force action is pressed against the inner circumferential surface of the passage portion, thereby The structure is such that the flow of liquid and mist from the gap 11 is blocked.

The gas expansion seal member 12 includes a support rod 13 projecting toward the outer wall of the labyrinth seal 9 and a gas inlet / outlet in a gap 11 formed by the labyrinth seal 9 and the disc cover 4. It is composed of an inflatable annular bag member made of an elastic body, preferably heat-resistant rubber, attached to the tip, and when performing a steam sterilization treatment (SIP) or the like inside the casing 3 with the rotating shaft 2 stopped In addition, it is an auxiliary sealing means provided to prevent water vapor from being mixed into the lubricating oil inside the frame 5, and a pressurized working fluid such as instrumentation air is supported on the gas expansion seal member 12 by supporting the support rod 13. It is inflated by supplying the air through the gap 11 and / or the passage portion of the labyrinth seal 9 and seals the inside of the casing 3 reliably and easily. The material of the elastic body of the annular bag portion can be selected depending on the fluid in contact with the outside, and a silicon rubber material is preferable when used for the SIP.

In addition, when the SIP is terminated while the centrifuge is stopped and the centrifuge is restarted, gas such as instrumentation air held to pressurize and expand the rubber in the annular bag portion is discharged. Therefore, the gas expansion seal member 12 does not come into contact with various rotating members. The direction of expansion of the elastic annular bag member attached to the tip of the support rod 13 is not only the radial direction but also an annular bag that expands in the thrust direction depending on the arrangement of the support rod 13. May be.

Separating plate centrifuges used in oil industry, chemical industry, food industry, cleaning of lubricating oil and fuel oil in ships, especially pharmaceuticals that require cleaning operation and steam sterilization (SIP) inside casing It is a centrifuge that can be suitably used for applications in the field of manufacturing food and beverages and biotechnology-related fields, and is easy to maintain due to its simple structure and can seal the inside of a casing at low cost. .

It is principal part sectional drawing of the separation plate type centrifuge of this invention. (Example 1) It is rotary body explanatory drawing of a separation plate type centrifuge. It is a whole block explanatory view of a separation plate type centrifuge.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating body 2 Rotating shaft 3 Casing 4 Disc cover 5 Frame 6 Radial bearing 7 Bearing case 8 Bearing cover 9 Labyrinth seal 10 Water supply device 11 Gap part 12 Gas expansion seal member 13 Support rod 31 Rotation drive means

Claims (2)

A rotating body comprising a rotating body and a lid part covering the upper part of the rotating body and having a sludge discharge hole in the outer peripheral part, and a separating plate made of a truncated conical thin plate mounted in the rotating body is an axial direction of the rotating body A plurality of separator plates and a valve cylinder that opens and closes a sludge discharge hole, and an upper end fastened to a lower axis of the rotating body and is driven to rotate by rotation driving means. A separating plate type centrifuge provided with a rotating shaft for rotating the casing, a casing for covering the whole of the rotating body, and a frame for mounting and fixing the casing and for covering the rotation driving means. A labyrinth seal that seals the gap between the rotating shaft and the rotating body, and contracts when the rotating body rotates to separate from the rotating shaft and / or the labyrinth seal, and expands when the rotating body stops. Serial casing and the gap portion and / or the separation plate type centrifuge, characterized in that said providing the annular gas expansion seal member for sealing the passage of the labyrinth seal and the rotating shaft. An annular bag made of heat-resistant rubber, wherein the annular gas expansion seal member has a support rod and a gas inlet / outlet protruding from the inner wall of the casing or frame toward the outer wall of the labyrinth seal, and is attached to the tip of the support rod The separation plate type centrifugal separator according to claim 1, comprising a member.

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