Seal structure and centrifugal degasser

Abstract

The present invention provides a sealing structure that can prevent liquid leakage at the connection between the fixed-side member and the rotating-side member, even when the contained liquid contains solid particles. [Solution] The seal structure 1 prevents liquid from leaking at the connection between the fixed-side member and the rotating-side member. The fixed-side member has a fixed-side cylindrical portion 22 that extends vertically and has a vertically extending flow path F1 inside, and a wall portion 21a that extends radially outward from the upper end of the fixed-side cylindrical portion 22 at the connection portion. The rotating-side member has a cylindrical rotating-side cylindrical portion 32 that extends toward the outer surface of the wall portion 21a at a position radially outward from the fixed-side cylindrical portion 22 at the connection portion. The seal structure 1 has a sealing gas containment space 11 that extends vertically between the fixed-side cylindrical portion 22 and the rotating-side cylindrical portion 32, with its upper side covered by the wall portion and its lower side opening to the liquid containment space S2 inside the rotating-side member, and functions as a seal.

Description

Technical Field

[0001] The present invention relates to a sealing structure for sealing a connection portion between a fixed-side member having a liquid storage space inside and a rotary-side member having a liquid storage space inside and rotatably connected to the fixed-side member, and a centrifugal defoaming machine in which the connection portion is sealed by the sealing structure.

Background Art

[0002] There is known a centrifugal defoaming machine that performs a defoaming process of applying a centrifugal force to a liquid containing bubbles by rotation to collect the bubbles toward the rotation center side, and separating the liquid with reduced bubbles from the liquid in which the bubbles are collected. For example, Patent Document 1 discloses a centrifugal defoaming machine having a rotor of a cylindrical box body configured to be rotatable about a rotation axis, and performing a defoaming process of applying a centrifugal force to a stock solution existing in a defoaming processing chamber in the rotor and containing bubbles to collect the bubbles near the rotation axis, and separating the defoamed liquid after the treatment from the bubble liquid in which the bubbles are collected.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a device such as the centrifugal degasser disclosed in Patent Document 1, in which a rotating member rotates relative to a fixed member and each contains a liquid, a sealing member is placed at the connection portion between the fixed member and the rotating member to prevent leakage of the liquid. In a device in which the sealing member is placed at the connection portion, the rotating member rotates while in contact with the sealing member. Therefore, if the liquid contained in the device is a liquid containing solid particles such as slurry, there is a possibility that the solid particles will be trapped between the sealing member and the rotating member as the rotating member rotates. As a result, the sealing member may wear down, and there is a possibility that the liquid will leak from the connection portion between the fixed member and the rotating member.

[0005] Therefore, there is a need for a sealing structure that can prevent liquid from leaking out from the connection between the fixed-side member and the rotating-side member, even when the liquid contains solid particles such as slurry.

[0006] The object of the present invention is to provide a sealing structure that can prevent liquid from leaking from the connection between a fixed-side member and a rotating-side member, even when the contained liquid contains solid particles. [Means for solving the problem]

[0007] A seal structure according to one embodiment of the present invention is a seal structure that prevents liquid flowing from the fixed side member to the rotating side member from leaking out at the connection portion between a fixed side member having a fixed side liquid containment space inside and a rotating side member having a rotating side liquid containment space inside and being rotatably connected to the fixed side member about an axis extending vertically. The fixed side member has, at the connection portion, a fixed side cylindrical portion which is vertically extending and forms a vertically extending flow path inside that connects the fixed side liquid containment space and the rotating side liquid containment space, and a wall portion which extends radially outward from the upper end of the fixed side cylindrical portion. The rotating side member has, at the connection portion, a cylindrical rotating side cylindrical portion which extends toward the wall portion at a position radially outward from the fixed side cylindrical portion. The seal structure extends vertically between the fixed side cylindrical portion and the rotating side cylindrical portion, and has a sealing gas containment space that functions as a seal, with its upper side covered by the wall portion and its lower side opening into the rotating side liquid containment space (first configuration).

[0008] In the above configuration, a sealing gas containment space is located at the connection point between the fixed-side member and the rotating-side member, opening into the rotating-side liquid containment space and extending upward to function as a seal. The sealing gas containment space acts as a buffer. Therefore, the sealing gas containment space prevents the liquid contained in the rotating-side liquid containment space from moving beyond the sealing gas containment space.

[0009] Furthermore, the fixed-side cylindrical portion and the rotating-side cylindrical portion that constitute the sealing gas containment space are separated radially. Therefore, even if a liquid containing solid particles enters the sealing gas containment space, the solid particles will not get stuck in the connection portion between the fixed-side member and the rotating-side member. Thus, even if the contained liquid contains solid particles, a sealing structure can be provided that prevents liquid from leaking from the connection portion between the fixed-side member and the rotating-side member.

[0010] The first configuration further includes a sealing member that restricts the movement of gas from above the sealing gas containment space to below the wall and radially outward of the rotating cylindrical portion (second configuration).

[0011] This restricts the outflow of gas from the upper side of the sealing gas containment space, allowing the gas contained within the sealing gas containment space to function as an air reservoir. Therefore, it is possible to prevent liquid from entering the sealing gas containment space.

[0012] In the first or second configuration described above, the rotating member is rotatably supported by the fixed member by a bearing portion supported by the fixed member (third configuration). This prevents liquid from leaking from the bearing portion located at the connection between the fixed member and the rotating member.

[0013] In the first or second configuration described above, the upper end of the sealing gas containment space is located above a position from which the liquid in the rotating liquid containment space, which is subjected to the liquid supply pressure of the liquid flowing from the fixed side member to the rotating side member and the centrifugal force due to the rotation of the rotating side member, can rise from the opening (fourth configuration).

[0014] The liquid contained in the rotating liquid containment space is subjected to the liquid supply pressure from the liquid flowing from the stationary member. As a result, the liquid may enter the interior through the lower opening of the sealing gas containment space and rise. Furthermore, when the rotating member rotates, centrifugal force is generated in the liquid contained in the rotating liquid containment space of the rotating member. Therefore, when the rotating member rotates, the liquid pressure on the outer circumference of the rotating liquid containment space increases. As a result, the liquid may enter the interior through the lower opening of the sealing gas containment space and rise.

[0015] In contrast, in the above-described configuration, the upper end of the sealing gas containment space is located above the point at which the liquid can rise from the opening due to the liquid supply pressure and centrifugal force. Therefore, it is possible to prevent the liquid from reaching the upper end of the sealing gas containment space. Consequently, it is possible to prevent liquid from leaking from the connection portion between the fixed-side member and the rotating-side member.

[0016] In the first or second configuration described above, the sealing gas containment space has an enlarged diameter portion at its lower end, which is radially larger than that of the upper portion (fifth configuration).

[0017] This allows for a larger volume of the sealing gas containment space compared to the case without the enlarged diameter section. Therefore, compared to the case without the enlarged diameter section, the position that liquid entering the sealing gas containment space can reach through the opening can be lowered. Consequently, it is possible to more reliably prevent the liquid from reaching the upper end of the sealing gas containment space.

[0018] In the first or second configuration described above, the liquid is a liquid containing metal particles or carbon particles (sixth configuration).

[0019] The sealing structure prevents liquid leakage through a gas-containing sealing space. Therefore, even if the liquid contains metal or carbon particles, these particles will not get trapped in the connection between the stationary member and the rotating member. Consequently, even if the contained liquid contains metal or carbon particles, leakage of the liquid from the connection between the stationary member and the rotating member can be prevented.

[0020] A centrifugal defoamer according to one embodiment of the present invention comprises a fixed-side member having a fixed-side liquid containment space inside, and a rotating-side member having a rotating-side liquid containment space inside and being rotatably connected to the fixed-side member about an axis extending vertically. The centrifugal defoamer performs a defoaming process by applying centrifugal force through rotation to a liquid to be processed containing bubbles contained in the rotating-side liquid containment space of the rotating-side member, thereby collecting the bubbles towards the center of rotation, and separating the processed liquid from which the bubbles have been collected. The centrifugal defoamer has a seal structure at the connection portion between the fixed-side member and the rotating-side member to prevent leakage of liquid flowing from the fixed-side member to the rotating-side member. The fixed-side member has a fixed-side cylindrical portion that is vertically extending and has a vertically extending flow path inside that connects the fixed-side liquid containment space and the rotating-side liquid containment space, and a wall portion that extends radially outward from the upper end of the fixed-side cylindrical portion. The rotating side member has a cylindrical rotating side cylinder portion at the connecting portion, located radially outward from the fixed side cylinder portion, and extending toward the wall portion. The seal structure has a sealing gas containment space that extends vertically between the fixed side cylinder portion and the rotating side cylinder portion, with its upper side covered by the wall portion and its lower side opening into the rotating side liquid containment space, and functions as a seal (seventh configuration).

[0021] The sealing gas containment space of the above-described sealing structure prevents liquid in the rotating side liquid containment space from entering and rising into the sealing gas containment space through the lower opening of the sealing gas containment space. Therefore, a centrifugal degasser can be provided in which liquid leakage from the connection portion between the fixed side member and the rotating side member is prevented.

[0022] In the seventh configuration described above, the liquid to be treated is a liquid containing metal fine particles or carbon fine particles (eighth configuration).

[0023] The sealing structure prevents liquid leakage by means of a gas storage space for sealing. Therefore, even when the liquid processed by the centrifugal defoamer is a liquid containing metal fine particles or carbon fine particles, the metal fine particles or carbon fine particles are not sandwiched at the connection portion between the fixed-side member and the rotating-side member. Therefore, even when the liquid contains metal fine particles or carbon fine particles, a centrifugal defoamer can be provided in which liquid leakage from the connection portion between the fixed-side member and the rotating-side member is prevented.

Effect of the Invention

[0024] According to an exemplary embodiment of the present invention, a sealing structure that prevents leakage of liquid flowing from the fixed-side member to the rotating-side member at the connection portion between the fixed-side member and the rotating-side member is located between a fixed-side cylindrical portion that the fixed-side member has at the connection portion and a rotating-side cylindrical portion that the rotating-side member has at the connection portion, extends in the vertical direction, has an upper side closed by the wall portion and a lower side opening into a rotating-side liquid storage space, and has a gas storage space for sealing that functions as a seal.

[0025] In this configuration, the gas storage space for sealing that functions as a seal prevents the liquid stored in the rotating-side liquid storage space from entering between the fixed-side cylindrical portion that the fixed-side member has at the connection portion and the rotating-side cylindrical portion that the rotating-side member has at the connection portion. Therefore, even when the liquid contains solid particles, the solid particles are not sandwiched between the fixed-side member and the rotating-side member. Therefore, even when the stored liquid contains solid particles, a sealing structure that can prevent liquid leakage from the connection portion between the fixed-side member and the rotating-side member can be provided.

Brief Description of the Drawings

[0026] [Figure 1] FIG. 1 is a cross-sectional view showing a schematic configuration of a centrifugal defoamer according to an embodiment. [Figure 2] FIG. 2 is a configuration diagram of a defoaming system including a centrifugal defoamer. [Figure 3] FIG. 3 is a partially enlarged view of part III in FIG. 1. [Modes for carrying out the invention]

[0027] The embodiments of the present invention will be described in detail below with reference to the drawings. Note that identical or corresponding parts in the drawings are denoted by the same reference numerals, and their descriptions will not be repeated. Furthermore, the dimensions of the components in each drawing do not faithfully represent the actual dimensions of the components or their dimensional ratios.

[0028] In the following explanation, in the centrifugal degassing machine 100, the direction parallel to the central axis P of the degassing casing 3 is referred to as the axial direction, the direction perpendicular to the central axis P is referred to as the radial direction, and the direction along the arc centered on the central axis P is referred to as the circumferential direction.

[0029] Furthermore, in the following explanation, the expressions "fix," "connect," and "attach" (hereinafter referred to as "fixing, etc.") include not only cases where components are directly fixed to each other, but also cases where they are fixed to each other via other components. In other words, in the following explanation, the expressions "fixing, etc." include both direct and indirect fixing of components to each other.

[0030] The seal structure 1 according to this embodiment is a seal structure that prevents liquid flowing from the fixed side member to the rotating side member from leaking out at the connection portion between a fixed side member having a fixed side liquid containment space inside and a rotating side member having a rotating side liquid containment space inside and being rotatably connected to the fixed side member about an axis extending vertically.

[0031] The seal structure 1 is used, for example, in a centrifugal degasser 100 incorporated into a degassing system 90, which will be described later. The following describes the case in which the device using the seal structure 1 is a centrifugal degasser 100.

[0032] (Centrifugal degasser) (Overall structure) Figure 1 is a cross-sectional view showing the schematic configuration of a centrifugal defoamer 100, which is an example of a device in which the seal structure 1 is used. The centrifugal defoamer 100 is generally cylindrical with a central axis P extending in the vertical direction. The centrifugal defoamer 100 is a device that performs defoaming by applying centrifugal force by rotation to a liquid to be treated L1 containing bubbles, which is housed in a defoaming section 31 of a defoaming treatment casing 3, thereby collecting the bubbles towards the center of rotation, and separating it into a treated liquid L2 with reduced bubbles and a treated liquid L3 in which bubbles have been collected. The liquid to be treated L1 may be a liquid containing solid particles. The liquid to be treated L1 may be a liquid containing metal fine particles or carbon fine particles, such as an electrode slurry.

[0033] As shown in Figure 1, the centrifugal degasser 100 includes a liquid to be processed casing 2, a degassing processing casing 3, a hollow shaft 4, a first processing liquid casing 5, a second processing liquid casing 6, and a shaft 7. The liquid to be processed casing 2, the degassing processing casing 3, the first processing liquid casing 5, and the second processing liquid casing 6 are each cylindrical in shape extending in the vertical direction and each has a liquid containment space inside for containing liquid.

[0034] The first processing liquid casing 5, the second processing liquid casing 6, and the liquid casing to be processed 2 are supported by a base (not shown) of the centrifugal degasser 100. That is, the first processing liquid casing 5, the second processing liquid casing 6, and the liquid casing to be processed 2 are fixed to the base. In this embodiment, the first processing liquid casing 5, the second processing liquid casing 6, and the liquid casing to be processed 2 are arranged in this order from top to bottom. The liquid casing to be processed 2 corresponds to the fixed side member of the present invention.

[0035] The defoaming casing 3 is cylindrical in shape and extends vertically, and is rotatably connected to the liquid casing 2 about a central axis P. The defoaming casing 3 is rotatably supported by the liquid casing 2 via a bearing portion 8. In this embodiment, the defoaming casing 3 is located below the liquid casing 2. The connection portion between the liquid casing 2 and the defoaming casing 3 is sealed by a seal structure 1. The defoaming casing 3 corresponds to the rotating side member of the present invention.

[0036] The hollow shaft 4 is tubular and extends vertically, and is positioned coaxially with the central axis P of the defoaming casing 3 inside the centrifugal defoamer 100. In this embodiment, the hollow shaft 4 rotates integrally with the defoaming casing 3. The hollow shaft 4 is rotatably supported by the first processing liquid casing 5 and the second processing liquid casing 6 via a bearing portion 8.

[0037] (Casing for the liquid to be treated) The liquid casing 2 has a liquid containment section 21, a wall section 21a, a fixed cylindrical section 22, a bearing support section 23, and a liquid supply port 24. The liquid containment section 21 is cylindrical and extends in the vertical direction. A plate-shaped wall section 21a with an opening in the center is connected to the lower side of the liquid containment section 21, extending radially inward from the lower end of the liquid containment section 21.

[0038] The liquid to be processed section 21 has a liquid storage space S1 inside. The liquid to be processed L1 containing air bubbles is supplied to the liquid storage space S1 from the liquid to be processed supply port 24. The liquid storage space S1 inside the liquid to be processed section 21 corresponds to the fixed-side liquid storage space of the present invention.

[0039] The wall portion 21a is fixed to the liquid to be treated container portion 21 by fixing members such as screws. Below the wall portion 21a is a bearing portion 8 that rotatably supports the liquid to be treated casing 2 and the defoaming treatment casing 3. Therefore, the wall portion 21a prevents the liquid to be treated L1 contained in the liquid container space S1 from flowing towards the bearing portion 8.

[0040] The fixed cylindrical portion 22 extends downward from the inner circumference of the opening provided in the wall portion 21a of the liquid to be processed portion 21. The upper opening of the fixed cylindrical portion 22 is connected to the liquid storage space S1. The lower opening of the fixed cylindrical portion 22 is connected to the liquid storage space S2 inside the defoaming processing casing 3. In other words, the fixed cylindrical portion 22 has a vertically extending flow path F1 inside that connects the liquid storage space S1 of the fixed cylindrical portion 22 to the liquid storage space S2 inside the defoaming processing casing 3. The liquid to be processed L1 supplied to the liquid storage space S1 passes through the flow path F1 inside the fixed cylindrical portion 22 and is supplied to the liquid storage space S2 inside the defoaming processing casing 3.

[0041] In this embodiment, the fixed cylindrical portion 22 and the wall portion 21a are formed integrally. That is, the wall portion 21a of the liquid to be treated portion 21 extends radially outward from the upper end of the fixed cylindrical portion 22. Note that the upper end is not limited to the very top, but also includes the portion slightly below the upper end.

[0042] In this embodiment, the radial thickness of the fixed cylindrical portion 22 is smaller than the thickness of the wall portion 21a. This prevents a reduction in the cross-sectional area of ​​the flow path F1. Furthermore, by making the thickness of the wall portion 21a larger than the radial thickness of the fixed cylindrical portion 22, the rigidity of the wall portion 21a when it is fixed with a fixing member such as a screw can be ensured.

[0043] The bearing support portion 23 is located radially outward from the fixed cylindrical portion 22 and extends downward from the outer surface of the wall portion 21a. The bearing support portion 23 supports the bearing portion 8, which rotatably supports the defoaming treatment casing 3. The defoaming treatment casing 3 is rotatably connected to the liquid casing 2 by the bearing portion 8.

[0044] (Degassed casing) The defoaming treatment casing 3 has a defoaming treatment section 31 and a rotating cylindrical section 32. The defoaming treatment section 31 is a cylindrical container with a bottom that extends vertically. The bottom section 31a is located at the lower part of the defoaming treatment section 31. The lid section 31b, which has an opening 31c in the center, is located at the upper part of the defoaming treatment section 31. The inner diameter of the opening 31c is larger than the inner diameter of the lower opening of the fixed cylindrical section 22.

[0045] The defoaming section 31 has a liquid containment space S2 inside. The liquid to be treated L1 supplied from the liquid to be treated casing 2 is contained in the liquid containment space S2. The liquid containment space S2 inside the defoaming section 31 corresponds to the rotating side liquid containment space of the present invention.

[0046] The rotating cylindrical portion 32 extends upward from the inner circumference of the opening 31c provided in the lid portion 31b of the degassing processing unit 31. More specifically, the rotating cylindrical portion 32 extends toward the wall portion 21a of the liquid casing 2 at a position radially outward from the fixed cylindrical portion 22 of the liquid casing 2 and radially inward from the bearing support portion 23 of the liquid casing 2. The rotating cylindrical portion 32 is rotatably connected to the liquid casing 2 via a bearing portion 8 connected to the bearing support portion 23 of the liquid casing 2.

[0047] This configuration creates a space between the inner circumferential surface of the rotating cylindrical portion 32 and the outer circumferential surface of the stationary cylindrical portion 22 in which a certain amount of gas can be contained. This space constitutes the sealing gas containment space 11 of the sealing structure 1, which will be described later. In addition, a space is created between the outer circumferential surface of the rotating cylindrical portion 32 and the inner circumferential surface of the bearing support portion 23 in which the sealing member 13, which will be described later, can be contained. This space constitutes the sealing member containment space 12, which will be described later.

[0048] In this embodiment, the rotating side cylinder portion 32 has a radially recessed notch portion 32a at the lower end of its inner circumferential surface. Therefore, at the lower end of the rotating side cylinder portion 32, the radial distance between the rotating side cylinder portion 32 and the stationary side cylinder portion 22 is greater than at the upper end.

[0049] A shaft 7 extending vertically and positioned coaxially with the central axis P is fixed to the outer center of the bottom 31a of the defoaming section 31. Alternatively, the shaft 7 may pass through the bottom 31a and be fixed to the lower end of the inner cylinder 41 of the hollow shaft 4. The shaft 7 rotates under power from a motor (not shown), causing the defoaming casing 3 to rotate around the central axis P. This rotation of the defoaming casing 3 generates centrifugal force within the defoaming section 31. As a result, bubbles in the liquid to be treated L1 supplied to the defoaming section 31 move towards the center of rotation, and the treated liquid L2, with reduced bubbles, moves to the outside of the liquid containment space S2. In other words, the liquid to be treated L1 within the defoaming section 31 is separated into treated liquid L2 with reduced bubbles and treated liquid L3 with collected bubbles.

[0050] A hollow shaft 4 extending vertically is fixed to the center of the inner surface of the bottom 31a of the degassing section 31, and is positioned coaxially with the central axis P.

[0051] (Hollow shaft) The hollow shaft 4 has an inner cylinder 41, an outer cylinder 42, and a regulating plate 43. The inner cylinder 41 and the outer cylinder 42 form a double-tube structure that extends in the vertical direction. That is, a space extending in the vertical direction is formed inside the inner cylinder 41. A space extending in the vertical direction is formed between the outer circumferential surface of the inner cylinder 41 and the inner circumferential surface of the outer cylinder 42.

[0052] The inner cylinder 41 and the outer cylinder 42 protrude from inside the defoaming section 31 through the opening 31c of the lid 31b towards the liquid casing 2. That is, the lower part of the hollow shaft 4 is located inside the defoaming section 31. In this embodiment, the inner cylinder 41, the outer cylinder 42, and the regulating plate 43 rotate integrally with the defoaming casing 3.

[0053] The inner cylinder 41 extends vertically within the second processing liquid casing 6, the liquid casing 2, and the defoaming processing casing 3. The lower end of the inner cylinder 41 is fixed to the center of the inner surface of the bottom 31a of the defoaming processing unit 31. The upper end of the inner cylinder 41 opens into the first processing liquid casing 5. The lower end of the inner cylinder 41 may also be fixed to the upper end of the shaft 7 that penetrates the bottom 31a, as described above.

[0054] A disc-shaped regulating plate 43 that expands radially is fixed to the portion of the inner cylinder 41 located within the degassing section 31.

[0055] The outer cylinder 42 extends radially outward from the inner cylinder 41 and vertically within the liquid casing 2 and the defoaming casing 3. The lower end of the outer cylinder 42 is located above the regulating plate 43 within the defoaming section 31. The upper end of the outer cylinder 42 opens into the second liquid casing 6.

[0056] A portion of the outer cylinder 42 is located radially inward relative to the fixed-side cylindrical portion 22 of the liquid casing 2. As described above, the fixed-side cylindrical portion 22 forms the flow path F1 of the liquid L1 to be treated. That is, the flow path F1 of the liquid L1 to be treated is formed by the inner circumferential surface of the fixed-side cylindrical portion 22 of the liquid casing 2 and the outer circumferential surface of the outer cylinder 42.

[0057] Between the lower end of the outer cylinder 42 and the regulating plate 43 in the vertical direction, there is a foam liquid intake port 42a for taking in the processing liquid L3 in which bubbles have been collected by the defoaming process in the defoaming processing section 31. The processing liquid L3 taken in from the foam liquid intake port 42a passes through a foam liquid flow path F3 formed by the inner circumferential surface of the outer cylinder 42 and the outer circumferential surface of the inner cylinder 41, and is discharged into the second processing liquid casing 6 from the opening at the upper end of the outer cylinder 42.

[0058] Below the regulating plate 43 within the liquid casing 2, the inner cylinder 41 is provided with a defoaming liquid intake port 41a for taking in the processed liquid L2, which has had its bubbles reduced by the defoaming treatment in the defoaming treatment section 31. The processed liquid L2 taken in through the defoaming liquid intake port 41a passes through the defoaming liquid flow path F2 configured inside the inner cylinder 41 and is discharged into the first processed liquid casing 5 from the opening at the upper end of the inner cylinder 41.

[0059] The regulating plate 43 restricts the movement of air bubbles contained in the liquid to be treated L1 supplied from the liquid to be treated casing 2 below the regulating plate 43. That is, when centrifugal force is applied to the liquid to be treated L1 due to the rotation of the liquid to be treated casing 2, the air bubbles contained in the liquid to be treated L1 move towards the center of rotation above the regulating plate 43 and do not move below the regulating plate 43. On the other hand, the liquid to be treated L2, from which the air bubbles have decreased, moves outward within the liquid containment space S2. Therefore, the liquid to be treated L2, from which the air bubbles have decreased, can move below the regulating plate 43 by passing radially outward. In this way, the regulating plate 43 separates the liquid to be treated L1 into the liquid to be treated L2, from which the air bubbles have been collected, and the liquid to be treated L3, from which the air bubbles have been collected.

[0060] (Second treatment liquid casing) In this embodiment, the second processing liquid casing 6 is fixed to the upper part of the processing liquid casing 2. Processing liquid L3, which has bubbles collected after being taken in from the foam liquid intake port 42a of the hollow shaft 4 and passing through the foam liquid flow path F3, is supplied to the second processing liquid casing 6. The processing liquid L3 supplied to the second processing liquid casing 6 is discharged to the outside from the discharge port 6a of the second processing liquid casing 6.

[0061] (First treatment liquid casing) In this embodiment, the first processing liquid casing 5 is fixed to the upper part of the second processing liquid casing 6. The first processing liquid casing 5 is supplied with processing liquid L2, which has been taken in from the defoaming liquid intake port 41a of the hollow shaft 4, passed through the defoaming liquid flow path F2, and has reduced bubbles. The processing liquid L2 supplied to the first processing liquid casing 5 is discharged to the outside from the outlet port 5a of the first processing liquid casing 5.

[0062] (Defoaming system) Figure 2 is a diagram showing the configuration of a defoaming system 90 including a centrifugal defoamer 100. The defoaming system 90 is an in-line system that defoams the liquid to be treated L1 using the centrifugal defoamer 100. In an in-line system having a supply port and a discharge port, liquid supply is necessary, and liquid supply pressure is applied to the treated liquid, making it prone to leakage to the outside. For this reason, the seal structure 1 of the present invention is useful for the centrifugal defoamer 100 incorporated into the in-line system.

[0063] As shown in Figure 2, the defoaming system 90 includes a centrifugal defoamer 100, a tank 91 for the liquid to be treated, a pump 92, piping 93, a supply unit 90a, and a discharge unit 90b. Each operation of the system is controlled by a control unit (not shown).

[0064] The liquid to be treated tank 91 contains the liquid to be treated L1, which is to be defoamed by the centrifugal defoamer 100. The liquid to be treated L1 is supplied to the liquid to be treated tank 91 from the supply unit 90a. The liquid to be treated L1 in the liquid to be treated tank 91 is sent by the pump 92 through the piping 93 to the liquid to be treated casing 2 of the centrifugal defoamer 100. The liquid to be treated L1 sent to the liquid to be treated casing 2 is then sent into the defoaming casing 3.

[0065] As the defoaming casing 3 rotates around its central axis P, the liquid to be treated L1 is separated into a liquid with reduced bubbles L2 and a liquid with collected bubbles L3. At this time, the liquid to be treated L1 inside the defoaming casing 3 is subjected to centrifugal force due to rotation and the liquid pressure from the pump 92.

[0066] The processing liquid L3, from which air bubbles have been collected, is sent into the second processing liquid casing 6. Part of it is discharged through the piping 93 to the outside of the centrifugal defoamer 100 via the discharge port 90b, and the remainder is returned to the processing liquid tank 91 through the piping 93. The processing liquid L2, from which the air bubbles have been reduced, is sent into the first processing liquid casing 5 and discharged through the piping 93 to the outside of the centrifugal defoamer 100 via the discharge port 90b.

[0067] (Seal structure) Next, the seal structure 1 used in the centrifugal defoamer 100 will be described. Figure 3 is a partially enlarged view of part III of Figure 1. The seal structure 1 is used at the connection between the liquid casing 2 and the defoaming treatment casing 3, and prevents liquid leakage at the connection. That is, the seal structure 1 is positioned at the connection between the liquid casing 2 and the defoaming treatment casing 3, and seals the internal space inside the centrifugal defoamer 100 from the external space inside the centrifugal defoamer 100.

[0068] As shown in Figure 3, the seal structure 1 includes a sealing gas containment space 11, a sealing member containment space 12, a sealing member 13, a filling member 14, and a sealing member 15.

[0069] The sealing gas containment space 11 is located between the fixed-side cylindrical portion 22 and the rotating-side cylindrical portion 32 and extends in the vertical direction. Above the sealing gas containment space 11 is a wall portion 21a that extends radially outward from the upper end of the fixed-side cylindrical portion 22.

[0070] The sealing gas containment space 11 opens at its lower side to the liquid containment space S2 within the degassing treatment casing 3. The upper side of the sealing gas containment space 11 is connected to the sealing member containment space 12. The sealing gas containment space 11 contains a gas such as air. The sealing gas containment space 11 acts as a buffer for the liquid containment space S2, preventing the liquid contained in the liquid containment space S2 from moving further into the sealing gas containment space 11.

[0071] As described above, the liquid to be treated L1 inside the defoaming casing 3 is subjected to the pressure of the liquid flowing from the liquid to be treated casing 2 and the centrifugal force caused by the rotation of the defoaming casing 3. Therefore, liquid may enter the sealing gas containment space 11.

[0072] In this embodiment, the vertical lengths of the fixed-side cylindrical portion 22 and the rotating-side cylindrical portion 32 are configured such that even when the liquid to which the liquid supply pressure and centrifugal force are applied enters the sealing gas containment space 11 through the opening and rises within the sealing gas containment space 11, it will not reach the upper end.

[0073] In other words, the upper end of the sealing gas containment space 11 is located above the position from which the liquid in the liquid containment space S2, which is subjected to the liquid supply pressure of the liquid flowing from the liquid casing 2 to the defoaming treatment casing 3 and the centrifugal force due to the rotation of the defoaming treatment casing 3, can rise from the opening.

[0074] This prevents the liquid from reaching the upper end of the sealing gas containment space 11.

[0075] As described above, in this embodiment, the rotating cylindrical portion 32 has a radially recessed notch 32a at the lower end of its inner circumferential surface. Therefore, the sealing gas containment space 11 has an enlarged diameter portion 111 at its lower end, which is radially larger than that of the upper portion. The enlarged diameter portion 111 increases the volume at the lower end of the sealing gas containment space 11.

[0076] This allows the volume of the sealing gas containment space 11 to be increased compared to the case without the enlarged diameter section. Therefore, the position that the liquid to be treated L1 can reach in the sealing gas containment space 11 can be lowered compared to the case without the enlarged diameter section. Consequently, it is possible to more reliably prevent the liquid to be treated L1 from reaching the upper end of the sealing gas containment space 11.

[0077] The seal member housing space 12 is located below the wall portion 21a and between the bearing support portion 23 and the rotating side cylindrical portion 32. That is, the wall portion 21a is located above the seal member housing space 12. The bearing portion 8 is located below the seal member housing space 12.

[0078] The seal member housing space 12 is connected to the sealing gas housing space 11. The seal member 13, the filling member 14, and the bearing portion 8 are arranged in the seal member housing space 12.

[0079] The sealing member 13 restricts the movement of gas in the sealing gas containment space 11 into the sealing member containment space 12. The sealing member 13 is, for example, an O-ring or an oil seal. That is, the sealing structure 1 has a sealing member 13 that restricts the movement of gas from the upper side of the sealing gas containment space 11 downwards of the wall portion 21a and radially outward of the rotating cylindrical portion 32.

[0080] This restricts the outflow of gas from the upper side of the sealing gas containment space 11, allowing the gas contained within the sealing gas containment space 11 to function as an air reservoir. Therefore, it is possible to prevent liquid from entering the sealing gas containment space 11.

[0081] The filling member 14 is positioned within the seal member housing space 12. The filling member 14 fills the space within the seal member housing space 12. The filling member 14 is, for example, a gap-filling ring made of stainless steel. The material of the filling member is not particularly limited.

[0082] The sealing member 15 is positioned between the sealing member 13 and the bearing portion 8 within the sealing member housing space 12. The sealing member 15 is, for example, grease. The sealing member 15 seals the bearing portion 8 side of the sealing member housing space 12. In other words, the sealing member 15 seals the outside air side of the sealing member housing space 12. This makes it possible to more reliably prevent liquid from entering the sealing gas housing space 11.

[0083] The seal structure 1, with the above configuration, prevents leakage of liquid flowing from the liquid casing 2 to the defoaming casing 3 at the connection portion between the liquid casing 2, which has a liquid containment space S1 inside, and the defoaming treatment casing 3, which has a liquid containment space S2 inside and is rotatably connected to the liquid casing 2 about an axis extending vertically. The liquid casing 2 has, at the connection portion, a fixed side cylindrical portion 22 that is vertically extending and forms a vertically extending flow path F1 inside that connects the liquid containment space S1 and the liquid containment space S2, and a wall portion 21a that extends radially outward from the upper end of the fixed side cylindrical portion 22. The defoaming treatment casing 3 has, at the connection portion, a cylindrical rotating side cylindrical portion 32 that extends toward the outer surface of the wall portion 21a at a position radially outward from the fixed side cylindrical portion 22. The seal structure 1 has a sealing gas containment space 11 that extends vertically between the fixed side cylindrical portion 22 and the rotating side cylindrical portion 32, with its upper side covered by a wall portion 21a and its lower side opening to the liquid containment space S2, thereby functioning as a seal.

[0084] In the above configuration, a sealing gas containment space 11 is located at the connection point between the liquid casing 2 and the defoaming treatment casing 3. This space opens into the liquid containment space S2 of the defoaming treatment casing 3 and extends upward, functioning as a seal. The sealing gas containment space 11 acts as a buffer. Therefore, the sealing gas containment space 11 prevents the liquid contained in the liquid containment space S2 from moving beyond the sealing gas containment space 11.

[0085] Furthermore, the fixed-side cylindrical portion 22 and the rotating-side cylindrical portion 32 that constitute the sealing gas containment space 11 are separated radially. Therefore, even if a liquid containing solid particles enters the sealing gas containment space 11, the solid particles will not get stuck in the connection portion between the liquid casing 2 and the defoaming treatment casing 3. Thus, even if the contained liquid contains solid particles, a sealing structure 1 can be provided that prevents liquid from leaking from the connection portion between the liquid casing 2 and the defoaming treatment casing 3.

[0086] The centrifugal defoamer 100 according to this embodiment has a seal structure 1 with the above configuration at the connection portion between the liquid to be processed casing 2 and the defoaming processing casing 3, which prevents the liquid to be processed L1 flowing from the liquid to be processed casing 2 to the defoaming processing casing 3 from leaking out. This provides a centrifugal defoamer 100 in which the liquid to be processed L1 is prevented from leaking out from the connection portion between the liquid to be processed casing 2 and the defoaming processing casing 3.

[0087] In the centrifugal degasser 100 of this embodiment, the liquid to be processed L1 may be a liquid containing metal fine particles or carbon fine particles.

[0088] The seal structure 1 used in the centrifugal degasser 100 prevents leakage of the liquid to be processed L1 through a sealing gas containment space 11. Therefore, even if the liquid to be processed L1 by the centrifugal degasser 100 is a liquid containing metal particles or carbon particles, the metal particles or carbon particles will not get caught in the connection between the liquid to be processed casing 2 and the degassing casing 3. Thus, even when the liquid to be processed L1 contains metal particles or carbon particles, the centrifugal degasser 100 can be provided in which leakage of liquid from the connection between the liquid to be processed casing 2 and the degassing casing 3 is prevented.

[0089] (Other embodiments) Although embodiments of the present invention have been described above, the embodiments described above are merely examples for carrying out the present invention. Therefore, the invention is not limited to the embodiments described above, and it is possible to carry out the invention by appropriately modifying the embodiments described above without departing from the spirit of the invention.

[0090] In the above embodiment, the case in which the seal structure 1 is used in a centrifugal degassing machine 100 was described as an example. However, the seal structure may also be used in a device having a fixed-side member having a fixed-side liquid containment space inside, and a rotating-side member having a rotating-side liquid containment space inside and being rotatably connected to the fixed-side member about an axis extending vertically, to prevent leakage of liquid flowing from the fixed-side member to the rotating-side member at the connection portion between the fixed-side member and the rotating-side member.

[0091] The configuration of the centrifugal defoamer 100 using the seal structure 1 described in the above embodiment is just one example. The configuration of the centrifugal defoamer using the seal structure is not limited to the configuration described in the embodiment. For example, the second processing liquid casing of the centrifugal defoamer does not have to be fixed to the upper part of the processing liquid casing. The first processing liquid casing does not have to be fixed to the upper part of the second processing liquid casing. The hollow shaft does not have to rotate. A part of the hollow shaft may rotate integrally with the defoaming processing casing, and the rest of the hollow shaft may not rotate.

[0092] In the above embodiment, the fixed cylindrical portion 22 and the wall portion 21a of the liquid casing 2 are formed integrally. However, the fixed cylindrical portion and the wall portion may be separate.

[0093] Furthermore, in each figure, the wall portion 21a extends radially outward from the upper end of the fixed-side cylindrical portion 22. However, the wall portion may also extend radially outward from a position slightly below the upper end of the fixed-side cylindrical portion.

[0094] In the above embodiment, the radial dimension of the fixed cylindrical portion 22 is smaller than the thickness of the wall portion 21a. However, the radial dimension of the fixed cylindrical portion may be equal to the thickness of the wall portion, or it may be larger than the thickness of the wall portion.

[0095] In the above embodiment, the case in which the seal structure 1 is used at the connection between the liquid casing 2 to be processed and the defoaming treatment casing 3 of the centrifugal defoamer 100 was described. However, the seal structure may also be used at the connection between the first treatment liquid casing and the hollow shaft. The seal structure may also be used at the connection between the second treatment liquid casing and the hollow shaft.

[0096] In the above embodiment, the sealing gas containment space 11 has an enlarged diameter portion 111 at its lower end, which is larger in the radial direction than the upper portion. However, the radial direction of the sealing gas containment space may be the same from the upper end to the lower end.

[0097] In the above embodiment, the enlarged diameter portion 111 of the sealing gas containment space 11 is formed by a notch 32a provided on the inner circumferential surface of the rotating side cylindrical portion 32. However, the enlarged diameter portion of the sealing gas containment space may also be formed by a notch provided on the outer circumferential surface of the stationary side cylindrical portion 22.

[0098] In the above embodiment, the rotating cylindrical portion 32 of the degassing treatment casing 3 has a radially recessed notch 32a at the lower end of its inner circumferential surface. The enlarged diameter portion 111 of the sealing gas containment space 11 is formed by the notch 32a. Therefore, the radial dimension of the lower opening of the sealing gas containment space 11 is the same as the radial dimension of the upper part of the sealing gas containment space 11. However, the rotating cylindrical portion may have a notch at its lower end in which the radial dimension increases as it extends downward. In this case, the radial dimension of the lower opening of the sealing gas containment space may be larger than the radial dimension of the upper part of the sealing gas containment space. [Industrial applicability]

[0099] The present invention can be used in a device having a fixed-side member that contains liquid and a rotating-side member that contains liquid flowing from the fixed-side member, for sealing the connection portion between the fixed-side member and the rotating-side member. [Explanation of Symbols]

[0100] 1. Seal structure 2. Casing for the liquid to be treated (fixed side member) 3. Degassing treatment casing (rotating side member) 4 Hollow shaft 5. First treatment liquid casing 5a Outlet 6. Second treatment liquid casing 6a Outlet 7 shafts 8 Bearing section 11. Space for containing sealing gas 12. Sealing member housing space 13. Sealing member 14 Filling material 15 Sealing member 21 Liquid to be processed storage section 21a Wall section 22 Fixed side cylinder part 23 Bearing support part 24. Supply port for liquid to be treated 31 Degassing treatment section 31a bottom 31b Lid 31c aperture 32 Rotating side cylinder 32a Notch 41 Inner cylinder 41a Defoaming liquid intake port 42 Outer cylinder 42a Foam liquid intake port 43 Restriction board 90 Degassing System 90a supply section 90b Discharge section 91 Tank of liquid to be treated 92 pumps 93 Piping 100 Centrifugal degasser 111 Expanded diameter part F1 channel F2 Defoaming liquid flow path F3 Foam liquid channel L1 Liquid to be treated containing air bubbles L2 Processing solution (liquid) with reduced bubbles L3: Processing liquid (liquid) in which air bubbles have been collected. S1 Liquid containment space (fixed side liquid containment space) S2 Liquid containment space (rotating side liquid containment space)

Claims

1. A sealing structure that prevents liquid flowing from the fixed member to the rotating member from leaking out at the connection point between a fixed member having a fixed liquid containment space inside and a rotating member having a rotating liquid containment space inside and being rotatably connected to the fixed member about an axis extending vertically, The fixed side member has the following at the connection portion: A fixed cylindrical portion that is cylindrical in shape extending in the vertical direction and has a vertically extending flow path inside that connects the fixed liquid storage space and the rotating liquid storage space, A wall portion extending radially outward from the upper end of the fixed side cylindrical portion, It has, The rotating side member has a cylindrical rotating side section at the connecting portion that extends toward the wall portion at a position radially outward from the fixed side section, The seal structure extends vertically between the fixed side cylindrical portion and the rotating side cylindrical portion, and has a sealing gas containment space that functions as a seal, with its upper side covered by the wall portion and its lower side opening into the rotating side liquid containment space. Seal structure.

2. In the seal structure according to claim 1, The system further includes a sealing member that restricts the movement of gas from above the sealing gas containment space toward the wall portion and radially outward toward the rotating cylindrical portion. Seal structure.

3. In the seal structure according to claim 1 or claim 2, The rotating member is rotatably supported by the fixed member by a bearing portion supported by the fixed member. Seal structure.

4. In the seal structure according to claim 1 or claim 2, The upper end of the sealing gas containment space is located above the position from which the liquid in the rotating liquid containment space can rise from the opening, due to the liquid supply pressure of the liquid flowing from the fixed side member to the rotating side member and the centrifugal force due to the rotation of the rotating side member. Seal structure.

5. In the seal structure according to claim 1 or claim 2, The aforementioned sealing gas containment space has an enlarged diameter portion at its lower end, which is radially larger than that of the upper part. Seal structure.

6. In the seal structure according to claim 1 or claim 2, The aforementioned liquid is a liquid containing metal nanoparticles or carbon nanoparticles. Seal structure.

7. A fixed-side member having a fixed-side liquid storage space inside, A rotating side member having a rotating side liquid containment space inside and being rotatably connected to the fixed side member about an axis extending in the vertical direction, It has, A centrifugal defoaming machine that performs a defoaming treatment on a liquid to be treated containing bubbles contained in the liquid-containing space on the rotating side of the rotating side member, by applying centrifugal force through rotation to collect the bubbles toward the center of rotation, thereby separating the treated liquid from the treated liquid with reduced bubbles and the treated liquid from which the bubbles have been collected, The connection portion between the fixed-side member and the rotating-side member has a sealing structure to prevent leakage of liquid flowing from the fixed-side member to the rotating-side member. The fixed side member has the following at the connection portion: A fixed cylindrical portion that is cylindrical in shape extending in the vertical direction and has a vertically extending flow path inside that connects the fixed liquid storage space and the rotating liquid storage space, A wall portion extending radially outward from the upper end of the fixed side cylindrical portion, It has, The rotating side member has a cylindrical rotating side section at the connecting portion that extends toward the wall portion at a position radially outward from the fixed side section, The seal structure has a sealing gas containment space that extends vertically between the fixed side cylindrical portion and the rotating side cylindrical portion, with its upper side covered by the wall portion and its lower side opening into the rotating side liquid containment space, and which functions as a seal. Centrifugal degasser.

8. A centrifugal degasser according to claim 7, The liquid to be treated is a liquid containing metal fine particles or carbon fine particles. Centrifugal degasser.

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