Sealing elements and submerged pump systems

Abstract

To provide a sealing member and a submerged pump system capable of suppressing leakage of a residual gas when raising and lowering a pump.SOLUTION: A sealing member 3 seals an opening end 2a of a pump column 2 and hangs and supports a pump when raising and lowering the pump. The sealing member has a head plate 10 that has a through-hole 11 and is attached to an opening end, a lift shaft 20 that penetrates the through-hole and is raised and lowered between an ascending position and a descending position when raising and lowering the pump, and a bellows member 30 that expands / contracts according to the raising and lowering of the lift shaft. The bellows member is equipped with a bellows cylinder body 31 that covers an outer peripheral surface of a projecting part projecting upward from the head plate of the lift shaft, a first attaching member 32 that is disposed continuously to an upper end of the bellows cylinder body and is attached to an upper end surface of the lift shaft, and a second attaching member 33 that is disposed continuously to a lower end of the bellows cylinder body and is attached to an upper surface of the head plate.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a sealing member and a submerged pump system. [Background technology]

[0002] Submerged pumping systems are used to extract liquefied gas (such as liquefied natural gas or liquefied ammonia) from a storage tank in which the gas is stored (see, for example, Patent Document 1). The pump (submerged pump) of the submerged pumping system is housed in a pump column that extends from the ceiling of the storage tank into the liquefied gas and is immersed in the liquefied gas. A foot valve that opens under the pump's own weight is attached to the lower end of the pump column. The upper end of the pump column is liquid-tightly sealed by a head plate. A lift shaft that raises and lowers the pump is attached to the head plate and passes through the head plate. The space between the lift shaft and the head plate is liquid-tightly sealed by a sealing material (for example, a gland seal).

[0003] In a submerged pump system, the pump is removed from the storage tank for maintenance, for example. When the pump is stopped, the pump column is filled with residual liquefied gas and vaporized liquefied gas (vaporized gas). If the head plate is removed in this state, there is a technical problem in that the liquefied gas and vaporized gas (hereinafter collectively referred to as "residual gas") leak to the outside. Since most residual gases are flammable and / or toxic, they must be removed before the head plate is removed.

[0004] Residual gas is typically removed by introducing an inert gas, such as nitrogen, into the pump column with the foot valve closed. In this method, the pump is lifted by the lift shaft and the foot valve is closed before the inert gas is introduced. At this time, the lift shaft is raised to close the foot valve, which loosens the sealant beforehand. This weakens the sealant's sealing ability, potentially allowing a small amount of residual gas to leak through gaps in the sealant. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-132619 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a sealing member and a submerged pump system that can suppress leakage of residual gas when the pump is raised and lowered. [Means for solving the problem]

[0007] In one embodiment of the present invention, the sealing member seals an open end of a cylindrical pump column that houses a pump that is immersed in pumped liquid, and suspends and supports the pump when the pump is raised and lowered within the pump column, the sealing member comprising: a head plate having a through hole extending in the vertical direction and attached to the open end so as to close the open end; a lift shaft that is disposed through the through hole and raised and lowered between a raised position and a lowered position when the pump is raised and lowered; and a bellows member that expands and contracts in the axial direction of the lift shaft in response to the raising and lowering of the lift shaft. a shaft seal member disposed between the lift shaft and the head plate; The bellows member comprises a bellows cylindrical body that covers the outer peripheral surface of a protruding portion of the lift shaft that protrudes upward from the head plate, a first attachment member that is arranged contiguous with the upper end of the bellows cylindrical body and attached to the upper end surface of the lift shaft, and a second attachment member that is arranged contiguous with the lower end of the bellows cylindrical body and attached to the upper surface of the head plate. The lift shaft includes a first shaft portion and a second shaft portion having an outer diameter smaller than that of the first shaft portion, disposed below the first shaft portion, and inserted into the through hole, and the through hole includes a first hole portion into which a lower portion of the first shaft portion is inserted when the lift shaft is located at the lowered position, and a second hole portion having an inner diameter smaller than that of the first hole portion, disposed below the first hole portion, and into which the second shaft portion is inserted, and the shaft seal member is disposed between a lower end surface of the first shaft portion and a bottom surface of the first hole portion. .

[0008] One implementation of the present invention Aspects The submerged pump system in the above comprises a pump that is immersed in the pumped liquid, a cylindrical pump column that houses the pump, and the sealing member. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a sealing member and a submerged pump system that can suppress leakage of residual gas when the pump is raised and lowered. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional view showing an embodiment of a submerged pump system according to the present invention. [Figure 2] 1 is a schematic cross-sectional view showing an embodiment of a sealing member according to the present invention. [Figure 3] FIG. 3 is a schematic exploded cross-sectional view of the sealing member of FIG. 2. [Figure 4] 3 is a schematic cross-sectional view of the sealing member shown in FIG. 2 when a lift shaft of the sealing member is located at a raised position. [Figure 5] FIG. 10 is a schematic cross-sectional view showing a modified example of the sealing member according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of a sealing member and a submerged pump system according to the present invention will be described with reference to the drawings. In each drawing, the same members and elements are designated by the same reference numerals, and duplicated explanations will be omitted. In addition, in each drawing, the shape and size of each member are intentionally exaggerated compared to their actual dimensions in order to clarify the configuration of each member.

[0012] In the following description and drawings, "downward" refers to the direction of gravity, and "upward" refers to the opposite direction of downward.

[0013] ●Submerged pump system● First, an embodiment of a submerged pump system according to the present invention will be described.

[0014] ●Configuration of submerged pump system FIG. 1 is a schematic cross-sectional view showing an embodiment of a submerged pump system according to the present invention.

[0015] The submerged pump system 1 is attached to a storage tank T in which liquefied gas Lg is stored, and pumps the liquefied gas Lg from the storage tank T to the outside. The submerged pump system 1 includes a pump column 2, a sealing member 3, a support cable 4, a submerged pump (hereinafter referred to as "pump") 5, a foot valve 6, and a collar 7. In this embodiment, the liquefied gas Lg is liquefaction Ammonia. Liquefied ammonia is an example of the handled liquid in the present invention.

[0016] In the present invention, the handled liquid is not limited to liquefied ammonia, and may be, for example, liquefied natural gas.

[0017] The pump column 2 houses the pump 5 and functions as a liquid transport path for the liquefied gas Lg discharged from the pump 5. The pump column 2 is cylindrical in shape. The pump column 2 is disposed so as to penetrate the ceiling T1 of the storage tank T and extends from the ceiling T1 into the liquefied gas Lg. A liquid transport path R1 for the liquefied gas Lg is connected to the outer peripheral surface of the upper part of the pump column 2.

[0018] The sealing member 3 liquid-tightly seals the upper open end 2a of the pump column 2, and also suspends and supports the pump 5 via the support cable 4 when the pump 5 is raised and lowered within the pump column 2. The sealing member 3 is one example of a sealing member according to the present invention, and its specific configuration will be described later.

[0019] The support cable 4 suspends and supports the pump 5 when the pump 5 is raised and lowered within the pump column 2. The support cable 4 is made of, for example, a metal wire. The support cable 4 is connected to the pump 5 and a lift shaft 20, which will be described later.

[0020] The pump 5 discharges the liquefied gas Lg that has flowed in through the foot valve 6 into the pump column 2. The pump 5 is, for example, a known submerged pump that is composed of a multi-stage centrifugal pump and a motor that drives the multi-stage centrifugal pump. Power for the pump 5 is supplied via a power cable (not shown) that is connected to the sealing member 3. The pump 5 is housed in the lower part of the pump column 2 and is immersed in the liquefied gas Lg.

[0021] The foot valve 6 opens and closes the lower open end 2b of the pump column 2. When the pump 5 is housed in the lower part of the pump column 2, the foot valve 6 opens due to the weight of the pump 5, and the pump 5 is suspended. the law of nature When raised, it closes under the biasing force of a spring (not shown).

[0022] The collar 7 fixes the lift shaft 20, which will be described later, in an elevated position, which will be described later. The collar 7 is cylindrically configured with two semi-cylindrical members 7a and 7b. That is, the collar 7 can be disassembled into the two semi-cylindrical members 7a and 7b. The collar 7 is a maintenance member that is used when the pump 5 is removed, and is not used while the pump 5 is in operation. For this reason, the collar 7 is shown in dashed lines in FIG. 1.

[0023] ●Configuration of sealing material Next, a specific configuration of the sealing member 3 (the sealing member according to the present invention) will be described.

[0024] FIG. 2 is a schematic cross-sectional view showing an embodiment of the sealing member 3. As shown in FIG. FIG. 3 is a schematic exploded cross-sectional view of the sealing member 3. As shown in FIG. Fig. 2 shows the sealing member 3 when a lift shaft 20 (described later) is in the lowered position. For ease of explanation, Fig. 2 also shows the upper part of the pump column 2. In the following explanation, bolt holes corresponding to bolts B1 to B5 (described later) are well known, and therefore will not be described here. In the following explanation, Fig. 1 will be referenced as appropriate.

[0025] The "lowered position" is a position (as shown in FIG. 2) in which the lift shaft 20 is lowered and its downward movement is restricted by a head plate 10, which will be described later. The "raised position" is a position (as shown in FIG. 4) in which the lift shaft 20 is raised and the collar 7 can be attached to the sealing member 3. In this embodiment, the raised position is a position in which the upward movement of the lift shaft 20 is restricted by a movement restricting member 90, which will be described later.

[0026] The sealing member 3 includes a head plate 10, a lift shaft 20, a bellows member 30, an upper sealing member 40, a lower sealing member 50, a shaft sealing member 60, a housing 70, a shaft fixing member 80, a movement restricting member 90, a plurality of plate mounting bolts B1, a plurality of bellows mounting bolts B2, a plurality of housing mounting bolts B3, a plurality of lid mounting bolts B4, and a plurality of pressing bolts B5.

[0027] The head plate 10 functions as a lid that closes the upper open end 2a of the pump column 2. The head plate 10 is, for example, disk-shaped. The head plate 10 is made of metal such as stainless steel. The head plate 10 includes an insertion hole 11, a seal groove 12, and a guide member 13.

[0028] The insertion hole 11 is a through-hole that penetrates the head plate 10 in the up-down direction. That is, the insertion hole 11 extends in the up-down direction in the head plate 10. The insertion hole 11 is disposed in the center of the head plate 10. The insertion hole 11 is an example of a through-hole in the present invention. The insertion hole 11 includes a first hole portion 11a and a second hole portion 11b.

[0029] The first hole 11a is a circular hole into which the lower part of a first shaft portion 21 (described later) of the lift shaft 20 is inserted when the lift shaft 20 is in the lowered position. The second hole 11b is a circular hole into which a second shaft portion 22 (described later) of the lift shaft 20 is inserted. The first hole 11a is disposed above the second hole 11b and continuous with the second hole 11b. The first hole 11a is disposed concentrically with the second hole 11b. The inner diameter of the first hole 11a is larger than the inner diameter of the second hole 11b.

[0030] The lower part of the second hole part 11b is expanded in diameter in two stages to form a fitting part 11c into which the guide member 13 is fitted.

[0031] The seal groove 12 is a ring-shaped groove in which the shaft seal member 60 is disposed. The seal groove 12 is disposed concentrically with the first hole portion 11a in the bottom surface 11d of the first hole portion 11a.

[0032] The guide member 13 guides the lift shaft 20 as it moves up and down. The guide member 13 is cylindrical in shape with a flange at its lower end. The guide member 13 is fitted into the fitting portion 11c of the second hole portion 11b. The inner diameter of the guide member 13 is approximately the same as the inner diameter of the second hole portion 11b. The dimensional tolerance (gap) of the inner diameter of the guide member 13 relative to the outer diameter of the lift shaft 20 (second shaft portion 22 described below) is smaller than the dimensional tolerance of the inner diameter of the second hole portion 11b.

[0033] When the pump 5 is raised or lowered, the lift shaft 20 is raised or lowered between a raised position and a lowered position, and supports the pump 5 via the support cable 4. The lift shaft 20 includes a first shaft portion 21, a second shaft portion 22, a first connecting member 23, a second connecting member 24, and a nut member 25.

[0034] The first shaft 21 restricts the lift shaft 20 from moving downward beyond its lowered position. The second shaft 22, together with the second hole 11b of the head plate 10, guides the lift shaft 20 as it moves up and down. The first shaft 21 and the second shaft 22 are cylindrical and elongated in the vertical direction. The first shaft 21 is disposed above and continuous with the second shaft 22, and is integral with the second shaft 22. That is, the first shaft 21 and the second shaft 22 form a single shaft body. The first shaft 21 is disposed concentrically with the second shaft 22. The outer diameter of the first shaft 21 is larger than the outer diameter of the second shaft 22 and slightly smaller than the inner diameter of the first hole 11a. The outer diameter of the second shaft 22 is slightly smaller than the inner diameter of the second hole 11b and the guide member 13.

[0035] The first shaft portion 21 has a female screw hole 21a that extends in the vertical direction and opens to an upper end surface 21b of the first shaft portion 21.

[0036] The second shaft portion 22 has a first female threaded hole 22a and a second female threaded hole 22b. The first female threaded hole 22a extends in the vertical direction and opens to a lower end surface 22c of the second shaft portion 22. The second female threaded hole 22b extends in the horizontal direction and opens to the outer peripheral surface of the lower part of the second shaft portion 22.

[0037] The first connecting member 23 is a member to which a cable (not shown) from a lift (not shown) is connected when the pump 5 is raised or lowered. The first connecting member 23 includes a ring-shaped connecting portion 23a and a male threaded portion 23b extending downward from the connecting portion 23a. The male threaded portion 23b is threadedly engaged with the female threaded hole 21a, whereby the first connecting member 23 is attached to the upper end of the first shaft portion 21.

[0038] The second connecting member 24 is a member to which the support cable 4 is connected. The second connecting member 24 includes a ring-shaped connecting portion 24a and an externally threaded portion 24b extending upward from the connecting portion 24a. The second connecting member 24 is attached to the lower end of the second shaft portion 22 by threading the externally threaded portion 24b into the first internally threaded hole 22a.

[0039] The nut member 25 presses a first mounting member 32 (described later) toward the upper end surface 21b of the first shaft portion 21. The nut member 25 is attached to the male thread portion 23b of the first connecting member 23.

[0040] The lift shaft 20 is inserted from above into the insertion hole 11 of the head plate 10 and is disposed so as to penetrate the insertion hole 11. The lift shaft 20 can be raised and lowered between a lowered position and an elevated position when the pump 5 is raised and lowered. The second shaft portion 22 of the lift shaft 20 is guided by the guide member 13, so that the lift shaft 20 can be raised and lowered smoothly without rattle.

[0041] When the lift shaft 20 is in the lowered position, the lower portion of the first shaft portion 21 is inserted into the first hole portion 11a, and the second shaft portion 22 is inserted through the second hole portion 11b and the guide member 13. At this time, the first shaft portion 21 protrudes upward from the head plate 10, and the second shaft portion 22 protrudes downward from the head plate 10 (into the pump column 2). On the other hand, when the lift shaft 20 is in the raised position, the first shaft portion 21 is located above the head plate 10. The second shaft portion 22 is inserted through the first hole portion 11a, the second hole portion 11b, and the guide member 13, and protrudes in the vertical direction from the head plate 10.

[0042] The bellows member 30 expands and contracts in the axial direction (vertical direction) of the lift shaft 20 in response to the elevation of the lift shaft 20, and provides a liquid-tight seal between the head plate 10 and the lift shaft 20. The bellows member 30 includes a bellows cylindrical body 31, a first mounting member 32, and a second mounting member 33.

[0043] The bellows tubular body 31 expands and contracts in response to the elevation of the lift shaft 20. The bellows tubular body 31 is a cylindrical bellows with ring-shaped peaks and valleys that are continuous in the vertical direction. The bellows tubular body 31 is made of a metal such as stainless steel. The inner diameter of the bellows tubular body 31 (the inner diameter of the valleys) is larger than the outer diameter of the first shaft portion 21 of the lift shaft 20. Furthermore, the outer diameter of the bellows tubular body 31 when extended (the outer diameter of the peaks) is smaller than the inner diameter of the collar 7.

[0044] The first mounting member 32 mounts the bellows cylindrical body 31 to the lift shaft 20. The first mounting member 32 is disposed above the bellows cylindrical body 31, continuous with the upper end 31a of the bellows cylindrical body 31. The first mounting member 32 is shaped like a ring plate. The first mounting member 32 has an insertion hole 32a and a seal groove 32b. The outer diameter of the first mounting member 32 is larger than the outer diameter of the bellows cylindrical body 31.

[0045] The insertion hole 32a is a through-hole that passes through the first mounting member 32 in the vertical direction. The insertion hole 32a is disposed in the center of the first mounting member 32. The inner diameter of the insertion hole 32a is smaller than the outer diameter of the first shaft portion 21.

[0046] The seal groove 32b is a ring-shaped groove in which the upper seal member 40 is disposed. The seal groove 32b is disposed on the lower surface 32c of the first mounting member 32 concentrically with the insertion hole 32a.

[0047] The second mounting member 33 mounts the bellows cylinder body 31 to the head plate 10. The shape of the second mounting member 33 is as follows: ring The second mounting member 33 is plate-shaped and is disposed below the bellows cylindrical body 31, continuous with the lower end 31b of the bellows cylindrical body 31. The second mounting member 33 has an insertion hole 33a.

[0048] The insertion hole 33a is a through-hole that passes through the second mounting member 33 in the vertical direction. The insertion hole 33a is disposed in the center of the second mounting member 33.

[0049] The upper end 31a of the bellows tubular body 31 is liquid-tight welded to the lower surface 32c of the first mounting member 32 around the entire circumferential circumference of the bellows tubular body 31. The lower end 31b of the bellows tubular body 31 is liquid-tight welded to the upper surface 33b of the second mounting member 33 around the entire circumferential circumference of the bellows tubular body 31. As a result, the bellows tubular body 31, the first mounting member 32, and the second mounting member 33 are integrally configured. In the radial direction of the first mounting member 32, the seal groove 32b is positioned inward of the upper end 31a of the bellows tubular body 31.

[0050] The bellows member 30 is attached to the upper surface 10a of the head plate 10 by fastening the second attachment member 33 to the head plate 10 with the bellows attachment bolts B2. The bellows tubular body 31 houses the portion of the lift shaft 20 that protrudes upward from the head plate 10 (hereinafter referred to as the "protruding portion") and covers its outer circumferential surface. The protruding portion changes as the lift shaft 20 rises and falls; at the lowered position, the protruding portion is part of the first shaft portion 21, and at the raised position, the protruding portion is the entire first shaft portion 21 and part of the second shaft portion 22. A space surrounded by the bellows tubular body 31 (hereinafter referred to as the "internal bellows space S") is formed between the bellows tubular body 31 and the lift shaft 20. The internal bellows space S allows for fluctuations in the inner diameter (outer diameter) of the bellows tubular body 31 as the bellows tubular body 31 expands and contracts.

[0051] The male thread portion 23b of the first connecting member 23 is inserted into the insertion hole 32a. The connecting portion 23a of the first connecting member 23 and the nut member 25 are disposed above the first mounting member 32. When the nut member 25, which is in contact with the upper surface 32d of the first mounting member 32, is tightened, the first mounting member 32 is pressed downward (toward the first shaft portion 21).

[0052] The upper seal member 40 is, for example, an O-ring made of fluororesin. The upper seal member 40 is disposed in the seal groove 32b of the first mounting member 32. The upper seal member 40 is disposed between the upper end surface 21b of the first shaft portion 21 of the lift shaft 20 and the lower surface 32c (seal groove 32b) of the first mounting member 32, and provides a liquid-tight seal between them. The sealing performance of the upper seal member 40 is determined by the tightening force of the nut member 25. That is, when the nut member 25 is loosened, the sealing performance decreases, and when the nut member 25 is tightened, the sealing performance improves.

[0053] The lower seal member 50 is, for example, a gasket made of fluororesin. The lower seal member 50 is disposed between the upper surface 10a of the head plate 10 and the lower surface 33c of the second mounting member 33, and provides a liquid-tight seal between them. The sealing performance of the lower seal member 50 is determined by the tightening force of the bellows mounting bolts B2. That is, when the bellows mounting bolts B2 are loosened, the sealing performance decreases, and when the bellows mounting bolts B2 are tightened, the sealing performance improves.

[0054] The shaft seal member 60 is, for example, an O-ring made of fluororesin. The shaft seal member 60 is disposed in the seal groove 12 of the head plate 10. When the lift shaft 20 is in the lowered position, the shaft seal member 60 is disposed between the bottom surface 11d (seal groove 12) of the first hole portion 11a of the head plate 10 and the lower end surface 21c of the first shaft portion 21 of the lift shaft 20, and provides a liquid-tight seal therebetween. The sealing performance of the shaft seal member 60 is determined by the tightening force of the pressing bolt B5, which will be described later. That is, when the pressing bolt B5 is loosened, the sealing performance decreases, and when the pressing bolt B5 is tightened, the sealing performance improves.

[0055] When the lift shaft 20 is in the lowered position, the housing 70 accommodates the first shaft portion 21 and the bellows member 30. The housing 70 includes a cylindrical portion 71, a first flange portion 72, a second flange portion 73, and a lid portion 74.

[0056] The cylindrical portion 71 has a cylindrical shape. The inner diameter of the cylindrical portion 71 is larger than the outer diameter (outer diameter of the peaks) of the bellows cylindrical body 31 and is smaller than the inner diameter of the collar 7. big The inner surface of the lower end of the cylindrical portion 71 is expanded in diameter to form an accommodation portion 71a that accommodates the second mounting member 33, the lower seal member 50, and the bellows mounting bolt B2. In the radial direction of the cylindrical portion 71, the upper end of the cylindrical portion 71 protrudes outward to form a ring-shaped first flange portion 72. The lower end of the cylindrical portion 71 protrudes outward to form a ring-shaped second flange portion 73. In other words, the cylindrical portion 71, the first flange portion 72, and the second flange portion 73 are integrally molded.

[0057] The lid portion 74 protects the inside of the cylindrical portion 71 from wind, rain, etc. The lid portion 74 is hat-shaped. The lid portion 74 is fastened to the first flange portion 72 of the cylindrical portion 71 with the lid mounting bolt B4, so that the lid portion 74 covers the upper opening of the cylindrical portion 71.

[0058] The housing 70 is attached to the upper surface 10a of the head plate 10 by fastening the second flange portion 73 to the head plate 10 with housing mounting bolts B3. At this time, the second mounting member 33, the lower seal member 50, and the bellows mounting bolts B2 are housed in the housing portion 71a.

[0059] When the lift shaft 20 is in the lowered position, the shaft fixing member 80 fixes the lift shaft 20 in the lowered position. The shaft fixing member 80 includes a peripheral wall portion 81 and a flange portion 82.

[0060] The peripheral wall portion 81 has a cylindrical shape. The outer diameter of the peripheral wall portion 81 is approximately the same as the outer diameter (outer diameter of the ridge portion) of the bellows tubular body 31. In the radial direction of the peripheral wall portion 81, the upper end of the peripheral wall portion 81 protrudes outward to form a ring-shaped flange portion 82. That is, the peripheral wall portion 81 and the flange portion 82 are integrally formed. The outer diameter of the flange portion 82 is larger than the outer diameter of the bellows tubular body 31. The peripheral wall portion 81 is inserted into the tubular portion 71. When the shaft fixing member 80 is not fastened to the housing 70 by the pressing bolt B5, the length of the portion of the peripheral wall portion 81 below the flange portion 82 in the vertical direction is longer than the length between the upper end surface 70a of the housing 70 and the upper surface 32d of the first mounting member 32. Therefore, the flange portion 82 does not abut against the upper end surface 70a of the housing 70.

[0061] The flange portion 82 is fastened to the housing 70 by the pressing bolts B5, thereby fastening the shaft fixing member 80 to the housing 70. At this time, the first mounting member 32 is pressed downward (toward the head plate 10 and lift shaft 20) by the pressing bolts B5. As a result, the first mounting member 32 presses the lift shaft 20 toward the head plate 10 via the upper seal member 40, fixing it in the lowered position. In this way, when the lift shaft 20 is in the lowered position, the shaft fixing member 80 presses the lift shaft 20 toward the head plate 10 via the first mounting member 32 and the upper seal member 40, fixing it in the lowered position.

[0062] The movement restricting member 90 restricts movement of the lift shaft 20 above its raised position. The movement restricting member 90 is, for example, a bolt made of metal such as stainless steel. The movement restricting member 90 is threadedly engaged with the second female threaded hole 22b of the second shaft portion 22. As a result, the movement restricting member 90 is positioned below the head plate 10 and protrudes from the outer circumferential surface of the second shaft portion 22.

[0063] The sealing member 3 configured in this manner is attached to the upper open end 2a of the pump column 2 by fastening the head plate 10 to the upper open end 2a with plate mounting bolts B1. At this time, a gasket (not shown) is placed between the upper open end 2a and the head plate 10, creating a liquid-tight seal between the head plate 10 and the upper open end 2a.

[0064] ●Sealing structure using sealing materials Next, the sealing structure using the sealing member 3 will be described with reference to FIGS. 1 to 3. The sealing member 3 seals the liquefied gas Lg in the pump column 2 and the vaporized liquefied gas Lg (hereinafter referred to as "vaporized gas Vg"). 」 (See Figure 4. Same below.) )andThe lift shaft 20 has a sealing structure that prevents the liquefied gas Lg and the vaporized gas Vg from leaking out of the sealing member 3. The sealing structure is made up of a bellows member 30, an upper seal member 40, a lower seal member 50, and a shaft seal member 60. The sealing structure can prevent the liquefied gas Lg and the vaporized gas Vg from leaking out of the sealing member 3 whether the lift shaft 20 is in the lowered position or the raised position.

[0065] Hereinafter, the sealing structure for each position of the lift shaft 20 will be described in relation to the operation of the sealing member 3 (mainly the lift shaft 20).

[0066] While the pump 5 is operating, the liquefied gas Lg discharged from the pump 5 rises inside the pump column 2 and is supplied to the outside of the storage tank T through the liquid supply line R1. The pump column 2 is filled with the liquefied gas Lg, and a discharge pressure (for example, a maximum of 2 MPa) from the pump 5 is applied to the head plate 10 and the lift shaft 20. At this time, the lift shaft 20 is positioned and fixed in a lowered position.

[0067] When the lift shaft 20 is in the lowered position, the liquefied gas Lg penetrates into the gap between the second shaft portion 22 of the lift shaft 20 and the guide member 13, but is blocked by the shaft seal member 60 and does not leak into the space above the shaft seal member 60 (the bellows space S). As a result, the discharge pressure described above is not transmitted to the bellows member 30, the upper seal member 40, and the lower seal member 50.

[0068] Furthermore, while the pump 5 is not operating, liquefied gas Lg remains in the pump column 2 up to the same height as the liquid level of the liquefied gas Lg in the storage tank T. Furthermore, the space above the liquid level in the pump column 2 is filled with vaporized gas Vg. Even in this state, the above-mentioned sealing structure (particularly, the shaft seal member 60) prevents the vaporized gas Vg from leaking into the space above the shaft seal member 60 (the bellows space S).

[0069] The pump 5 is periodically (for example, every few years) removed from the pump column 2 for maintenance. Removing the pump 5 requires closing the foot valve 6 and removing the residual gas (liquefied gas Lg and vaporized gas Vg) from the pump column 2. As a preparation for this, the lift shaft 20 is raised from the lowered position to the raised position, thereby lifting the pump 5 to a predetermined height within the pump column 2.

[0070] In preparation for lifting the lift shaft 20, the cover 74 and the shaft fixing member 80 are removed. As a result, the pressure applied by the pressure bolt B5 is released, reducing the sealing performance of the shaft seal member 60. Therefore, residual gas may leak past the shaft seal member 60 into the bellows space S. However, the bellows space S is liquid-tightly sealed by the bellows member 30, the upper seal member 40, and the lower seal member 50. Therefore, residual gas does not leak from the bellows space S to the outside of the sealing member 3. In this embodiment, the handled liquid is liquefied ammonia, and the vaporized gas Vg is ammonia gas, which is flammable and highly toxic to living organisms. Furthermore, ammonia gas is lighter than air and therefore easily inhaled by maintenance workers. The sealing member 3 according to the present invention has a sealing structure using the bellows member 30, making it applicable to handling liquids that are difficult to handle, such as liquefied ammonia.

[0071] Next, a cable (not shown) from a lift (not shown) is connected to the first connecting member 23 of the lift shaft 20, and the lift shaft 20 is raised to the raised position by the lift. At this time, the pump 5 is lifted up onto the lift shaft 20 via the support cable 4, and the foot valve 6 is closed by the biasing force of a spring (not shown).

[0072] FIG. 4 is a schematic cross-sectional view of the sealing member 3 when the lift shaft 20 is in the raised position.

[0073] When the lift shaft 20 is raised to the raised position, the sealing by the shaft seal member 60 is released, and the bellows internal space S communicates with the space inside the pump column 2 through the insertion hole 11. Therefore, the residual gas flows into the bellows internal space S through the insertion hole 11. At this time, the bellows cylindrical body 31 is extended in response to the movement of the lift shaft 20. Therefore, the sealing state of the bellows internal space S by the bellows member 30, the upper seal member 40, and the lower seal member 50 is maintained. Therefore, the residual gas does not leak from the bellows internal space S to the outside of the sealing member 3.

[0074] Furthermore, when the lift shaft 20 is raised to the raised position, the movement restricting member 90 comes into contact with the lower surface 10b of the head plate 10, thereby restricting the movement of the lift shaft 20 above the raised position. Therefore, the bellows cylindrical body 31 is not excessively stretched, and no technical problems such as damage to the bellows member 30 (the bellows cylindrical body 31 or the welded portion) occur.

[0075] Furthermore, the outer diameter of the bellows tubular body 31 when extended is smaller than the outer diameter of the bellows tubular body 31 when contracted. Meanwhile, as described above, the inner diameter of the collar 7 is larger than the outer diameter of the bellows tubular body 31 when extended and smaller than the inner diameter of the tubular body portion 71. Therefore, the collar 7 can be attached between the first mounting member 32 and the first flange portion 72 of the housing 70. When the collar 7 is attached between the first mounting member 32 and the first flange portion 72, the lift shaft 20 is fixed in an elevated position. At this time, the sealing member 3 supports the pump 5 by suspending it.

[0076] When the lift shaft 20 is in the raised position, the lower end surface 21c of the first shaft portion 21 is separated from the shaft seal member 60, and the sealing by the shaft seal member 60 is released. Therefore, residual gas flows into the bellows internal space S through the gap between the second shaft portion 22 and the insertion hole 11 (guide member 13). However, as described above, the sealing state of the bellows internal space S by the bellows member 30, the upper seal member 40, and the lower seal member 50 is maintained. Therefore, the residual gas does not leak from the bellows internal space S to the outside of the sealing member 3.

[0077] Next, an inert gas is introduced into the pump column 2, and the remaining gas in the pump column 2 is returned to the storage tank T. The subsequent removal process of the pump 5 is a known process, and therefore a description thereof will be omitted.

[0078] Summary According to the embodiment described above, the sealing member 3 includes a head plate 10, a lift shaft 20, and a bellows member 30. The head plate 10 has an insertion hole 11 extending in the vertical direction and is attached to the upper open end 2a of the pump column 2 so as to close the upper open end 2a. The lift shaft 20 is disposed to pass through the insertion hole 11 and is raised and lowered between an elevated position and a lowered position when the pump 5 is raised and lowered. The bellows member 30 expands and contracts in the axial direction (vertical direction) of the lift shaft 20 in response to the elevation and lowering of the lift shaft 20. The bellows member 30 includes a bellows cylindrical body 31, a first mounting member 32, and a second mounting member 33. The bellows cylindrical body 31 covers the outer peripheral surface of the protruding portion of the lift shaft 20. The first mounting member 32 is disposed contiguous with the upper end 31a of the bellows cylindrical body 31 and is attached to the upper end surface 21b of the first shaft portion 21. The second mounting member 33 is disposed contiguous with the lower end 31b of the bellows cylindrical body 31, and is attached to the upper surface 10a of the head plate 10. With this configuration, the bellows internal space S is surrounded by the bellows member 30. Therefore, even when the lift shaft 20 moves up and down, the bellows cylindrical body 31 expands and contracts in response to the movement of the lift shaft 20, and the bellows internal space S is sealed by the bellows member 30. In this way, in the sealing member 3, the bellows member 30 prevents leakage of the liquefied gas Lg and residual gas when the pump 5 moves up and down.

[0079] According to the embodiment described above, the sealing member 3 includes an upper seal member 40 and a lower seal member 50. The upper seal member 40 is disposed between the first mounting member 32 and the upper end surface 21b of the first shaft portion 21. The lower seal member 50 is disposed between the second mounting member 33 and the upper surface 10a of the head plate 10. With this configuration, the gap between the first mounting member 32 and the upper end surface 21b and the gap between the second mounting member 33 and the upper surface 10a are liquid-tightly sealed. As a result, the bellows internal space S is liquid-tightly sealed by the bellows member 30, the upper seal member 40, and the lower seal member 50. Therefore, in the sealing member 3, the bellows member 30, the upper seal member 40, and the lower seal member 50 prevent leakage of the liquefied gas Lg and residual gas when the pump 5 is raised and lowered.

[0080] Furthermore, according to the embodiment described above, the sealing member 3 includes a shaft seal member 60 disposed between the head plate 10 and the lift shaft 20. The lift shaft 20 includes a first shaft portion 21 and a second shaft portion 22. The second shaft portion 22 has an outer diameter smaller than that of the first shaft portion 21, is disposed below the first shaft portion 21, and is inserted through the insertion hole 11. With this configuration, when the lift shaft 20 is in the lowered position, the gap between the lower end surface 21c of the first shaft portion 21 and the head plate 10 is liquid-tightly sealed by the shaft seal member 60. As a result, when the lift shaft 20 is in the lowered position, neither the liquefied gas Lg nor residual gas leaks into the bellows space S. Furthermore, the discharge pressure of the pump 5 is not transmitted to the bellows member 30. As a result, the sealing performance of the sealing member 3 is improved, and technical problems such as damage to the bellows member 30 due to the discharge pressure do not occur.

[0081] Furthermore, according to the embodiment described above, the insertion hole 11 includes the first hole portion 11a and the second hole portion 11b. The second hole portion 11b has an inner diameter smaller than that of the first hole portion 11a and is disposed lower than the first hole portion 11a. When the lift shaft 20 is in the lowered position, the lower portion of the first shaft portion 21 is inserted into the first hole portion 11a. The second shaft portion 22 is inserted into the second hole portion 11b. The shaft seal member 60 is disposed between the lower end surface 21c of the first shaft portion 21 and the bottom surface 11d of the first hole portion 11a. According to this configuration, when the lift shaft 20 is in the lowered position, the gap between the lower end surface 21c and the bottom surface 11d is liquid-tightly sealed by the shaft seal member 60. As a result, when the lift shaft 20 is in the lowered position, the liquefied gas Lg and residual gas do not leak into the bellows space S. Furthermore, the discharge pressure of pump 5 is not transmitted to bellows member 30. As a result, the sealing performance of sealing member 3 is improved, and technical problems such as damage to bellows member 30 due to discharge pressure do not occur.

[0082] Furthermore, according to the embodiment described above, the sealing member 3 includes the shaft fixing member 80 that fixes the lift shaft 20 in the lowered position. The shaft fixing member 80 presses the lift shaft 20 toward the head plate 10 with the pressing bolt B5. With this configuration, even if the discharge pressure of the pump 5 is applied to the lift shaft 20, the lift shaft 20 is fixed in the lowered position. Furthermore, since the shaft seal member 60 is pressed between the lower end surface 21c of the first shaft portion 21 and the bottom surface 11d of the first hole portion 11a, the sealing performance of the shaft seal member 60 is improved.

[0083] Furthermore, according to the embodiment described above, the sealing member 3 has a movement restricting member 90 that restricts movement above the raised position of the lift shaft 20. With this configuration, the bellows tubular body 31 is not excessively stretched, and technical problems such as breakage of the bellows member 30 do not occur.

[0084] ●Other embodiments● In the present invention, the sealing member 3 does not necessarily have to include the shaft seal member 60. With this configuration, the discharge pressure from the pump 5 can be transmitted to the bellows member 30, but leakage of the liquefied gas Lg from the bellows internal space S is prevented by the bellows member 30, the upper seal member 40, and the lower seal member 50. Also, with this configuration, for example, by bringing the lower end surface 21c of the first shaft portion 21 and the bottom surface 11d of the first hole portion 11a into close contact with each other, a certain degree of sealing performance between them can be ensured and the transmission of the discharge pressure can also be suppressed.

[0085] Furthermore, in the present invention, the configuration for sealing the gap between the first mounting member 32 and the lift shaft 20 is not limited to the present embodiment. That is, for example, the first mounting member 32 may be attached to the lift shaft 20 in a liquid-tight manner by welding.

[0086] Furthermore, in the present invention, the upper seal member 40 is not limited to an O-ring, and may be, for example, a ring-shaped gasket.

[0087] Furthermore, in the present invention, the seal groove 32b in which the upper seal member 40 is disposed may be disposed in the upper end surface 21b of the first shaft portion 21.

[0088] Furthermore, in the present invention, the configuration for sealing the gap between the second mounting member 33 and the head plate 10 is not limited to the present embodiment. That is, for example, the second mounting member 33 may be attached to the head plate 10 in a liquid-tight manner by welding.

[0089] Furthermore, in the present invention, the lower seal member 50 is not limited to a gasket. That is, for example, the lower seal member 50 may be a ring-shaped O-ring. In this case, for example, a seal groove in which the lower seal member 50 is disposed may be arranged on the upper surface 10a of the head plate 10 or the lower surface 33c of the second mounting member 33.

[0090] Furthermore, in the present invention, bellows tubular body 31 may be molded integrally with first mounting member 32 and / or second mounting member 33. With this configuration, the strength of bellows member 30 is improved.

[0091] Furthermore, in the present invention, the insertion hole 11 does not necessarily have to include the first hole portion 11a. In this case, for example, the seal groove 12 into which the shaft seal member 60 is fitted may be disposed in the upper surface 10a of the head plate 10.

[0092] Furthermore, in the present invention, the seal groove 12 in which the shaft seal member 60 is disposed may be disposed in the lower end surface 21c of the first shaft portion 21.

[0093] Furthermore, in the present invention, the materials of the bellows member 30, the upper seal member 40, the lower seal member 50, and the shaft seal member 60 may be selected appropriately depending on the handled fluid, and are not limited to the present embodiment.

[0094] Furthermore, in the present invention, the shaft body formed by the first shaft portion 21 and the second shaft portion 22 may have the same outer diameter from the upper end to the lower end. That is, for example, the shaft body of the lift shaft 20 may be formed by only either the first shaft portion 21 or the second shaft portion 22. In this case, for example, the insertion hole 11 only needs to have an inner diameter that allows the lift shaft 20 to be inserted therethrough.

[0095] Furthermore, in the present invention, a female thread portion may be formed on the upper part of the inner peripheral surface of the cylindrical portion 71 of the housing 70, and a male thread portion corresponding to the female thread portion may be formed on the outer peripheral surface of the peripheral wall portion 81 of the shaft fixing member 80. According to this configuration, by threading the shaft fixing member 80 into the cylindrical portion 71, the shaft fixing member 80 can press the lift shaft 20 downward.

[0096] Furthermore, in the present invention, the sealing member 3 does not have to be provided with the movement restricting member 90. In this case, for example, it is sufficient if the height of the raised position is set in advance.

[0097] Furthermore, in the present invention, the configuration of movement restricting member 90 is not limited to this embodiment. That is, for example, movement restricting member 90 may be configured by a knock pin that is fitted into lift shaft 20. Also, for example, movement restricting member 90 may be configured by a slide rail with a stopper that is disposed between first mounting member 32 and second mounting member 33.

[0098] Furthermore, in the present invention, the head plate 10 does not necessarily have to include the guide member 13. In this case, for example, the second hole portion 11b may have the same function as the guide member 13.

[0099] Furthermore, in the present invention, the lift shaft 20 may be fixed by the collar 7 not at the raised position but at a holding position that is located below the raised position. In this case, the lift shaft 20 is raised to the raised position, the collar 7 is placed, and then the lift shaft 20 is lowered to the holding position. This configuration makes it easier to place the collar 7.

[0100] Furthermore, in the present invention, a gas path capable of introducing an inert gas into the bellows space S may be connected to the bellows member 30. In this case, for example, the gas path may be connected to the first mounting member 32. According to this configuration, when the lift shaft 20 is lowered to the lowered position, the liquefied gas Lg and vaporized gas Vg remaining in the bellows space S are released into the pump column 2. Furthermore, by introducing the inert gas into the pump column 2 and the bellows space S at the same time, the residual gas does not remain in the bellows space S.

[0101] Furthermore, in the present invention, the insertion hole 11 and the guide member 13 may have an air vent groove that bypasses the bellows internal space S and the space inside the pump column 2 when the pressure applied to the shaft seal member 60 by the pressure bolt B5 is released. This configuration facilitates the flow of air into the bellows internal space S and the flow of air out of the bellows internal space S. As a result, the bellows tubular body 31 can easily expand and contract.

[0102] Furthermore, in the present invention, when the flange portion 82 is fastened to the housing 70 by the pressing bolt B5, the flange portion 82 may or may not abut against the upper end surface 70a of the housing 70. In the former case, the force (pressing force) with which the shaft fixing member 80 presses the first mounting member 32 is uniform in the circumferential direction of the shaft fixing member 80. Furthermore, even if the shaft fixing member 80 is attached and detached multiple times, the pressing force is approximately the same each time it is attached. On the other hand, in the latter case, the pressing force can be adjusted to suit the state of the shaft seal member 60, for example.

[0103] Furthermore, in the present invention, the first mounting member 32 may be molded integrally with the shaft fixing member 80.

[0104] FIG. 5 is a schematic cross-sectional view showing a modified example of the sealing member according to the present invention. The figure shows the sealing member 3A according to this modification when the lift shaft 20 is in the raised position. The figure also shows that the bellows member 30A of the sealing member 3A according to this modification includes a first mounting member 34 having a shape in which the first mounting member 32 and the shaft fixing member 80 (both see FIG. 2) in the previously described embodiment are integrally molded. Furthermore, in the figure, only the cross section of the first mounting member 34 is painted gray to clearly show the first mounting member 34. The differences between this modification and the previously described embodiment will be described below.

[0105] In this modified example, the first mounting member 34 includes a ring-shaped bottom portion 34a, a cylindrical peripheral wall portion 34b extending upward from the outer edge of the bottom portion 34a, and a ring-shaped flange portion 34c protruding outward from the upper end of the peripheral wall portion 34b in the radial direction of the bottom portion 34a. The bottom portion 34a is disposed above and continuous with the upper end 31a of the bellows tubular body 31. The upper end 31a of the bellows tubular body 31 is liquid-tightly welded to the lower surface 34d of the bottom portion 34a around the entire circumferential circumference of the bellows tubular body 31. The seal groove 32b is disposed on the lower surface 34d of the bottom portion 34a. The outer diameter of the flange portion 34c is larger than the outer diameter of the bellows tubular body 31 (the outer diameter of the peak portion). According to this configuration, when the lift shaft 20 is in the raised position, the flange portion 34c protrudes outward from the bellows tubular body 31 in the radial direction of the bottom portion 34a. Therefore, a cylindrical collar 7A is attached between the flange portion 34c and the first flange portion 72 of the housing 70, thereby fixing the lift shaft 20 in the raised position. The collar 7A is composed of two semi-cylindrical members 7Aa and 7Ab. The inner diameter of the collar 7A is larger than the outer diameter of the peripheral wall portion 34b and smaller than the outer diameter of the flange portion 34c. By attaching the collar 7A between the flange portion 34c and the first flange portion 72, the head plate 10 can be removed from the upper open end 2a when the lift shaft 20 is fixed in the raised position (when the pump 5 is raised).

[0106] In this modification, the cylindrical portion 71, the first flange portion 72, and the second flange portion 73 of the housing 70 may be separable into two halves along the vertical direction. 4 After the second mounting member 33 is welded to the bellows cylindrical body 31, the cylindrical body portion 71 can accommodate the bellows member 30.

[0107] ●Embodiments of the present invention● Next, embodiments of the present invention that can be understood from the above-described embodiments will be described below, using the terms and symbols described in the embodiments.

[0108] A first embodiment of the present invention is a sealing member (e.g., sealing member 3, 3A) that seals an open end (e.g., upper open end 2a) of a cylindrical pump column (e.g., pump column 2) in which a pump (e.g., pump 5) immersed in a handled liquid (e.g., liquefied gas Lg) is accommodated, and that suspends and supports the pump when the pump is raised and lowered in the pump column. The sealing member has a through hole (e.g., insertion hole 11) extending in the vertical direction, and includes a head plate (e.g., head plate 10) attached to the open end so as to close the open end, a lift shaft (e.g., lift shaft 20) that is disposed through the through hole and raised and lowered between a raised position and a lowered position when the pump is raised and lowered, and a lift shaft (e.g., lift shaft 20) that is disposed through the through hole and raised and lowered between a raised position and a lowered position when the pump is raised and lowered. The bellows member is a sealing member comprising a bellows cylindrical body (e.g., bellows cylindrical body 31) that covers the outer peripheral surface of the protruding portion of the lift shaft that protrudes upward from the head plate, a first mounting member (e.g., first mounting member 32, 34) that is arranged contiguous with the upper end (e.g., upper end 31a) of the bellows cylindrical body and attached to the upper end surface (e.g., upper end surface 21b) of the lift shaft, and a second mounting member (e.g., second mounting member 33) that is arranged contiguous with the lower end (e.g., lower end 31b) of the bellows cylindrical body and attached to the upper surface (e.g., upper surface 10a) of the head plate. With this configuration, even when the lift shaft is raised or lowered, the bellows cylinder expands or contracts in response to the lift shaft's raising or lowering, and the gap can be sealed by the bellows member, thereby preventing leakage of residual gas when the pump is raised or lowered.

[0109] A second embodiment of the present invention is a sealing member comprising, in the first embodiment, an upper sealing member (e.g., upper sealing member 40) arranged between the first mounting member and the upper end surface of the lift shaft, and a lower sealing member (e.g., lower sealing member 50) arranged between the second mounting member and the upper surface of the head plate. According to this configuration, leakage of residual gas when the pump is raised and lowered can be prevented by the bellows member, the upper seal member, and the lower seal member.

[0110] A third embodiment of the present invention is the first or second embodiment, which comprises a shaft seal member (e.g., shaft seal member 60) arranged between the lift shaft and the head plate, wherein the lift shaft comprises a first shaft portion (e.g., first shaft portion 21) and a second shaft portion (e.g., second shaft portion 22) having an outer diameter smaller than that of the first shaft portion, arranged below the first shaft portion, and inserted into the through hole, and the shaft seal member is a sealing member arranged between the lower end surface (e.g., lower end surface 21c) of the first shaft portion and the head plate. According to this configuration, the sealing performance of the sealing member is improved, and technical problems such as damage to the bellows member due to discharge pressure do not occur.

[0111] A fourth embodiment of the present invention is the third embodiment, wherein the through hole comprises a first hole portion (e.g., first hole portion 11a) into which the lower part of the first shaft portion is inserted when the lift shaft is positioned in the lowered position, and a second hole portion (e.g., second hole portion 11b) having an inner diameter smaller than the inner diameter of the first hole portion, positioned lower than the first hole portion, and into which the second shaft portion is inserted, and the shaft seal member is a sealing member positioned between the lower end surface of the first shaft portion and a bottom surface (e.g., bottom surface 11d) of the first hole portion. According to this configuration, the sealing performance of the sealing member is improved, and technical problems such as damage to the bellows member due to discharge pressure do not occur.

[0112] A fifth embodiment of the present invention is any of the first to fourth embodiments, and includes a shaft fixing member (e.g., shaft fixing member 80) that fixes the lift shaft in the lowered position, and the shaft fixing member is a sealing member that presses the lift shaft toward the head plate via the first mounting member when the lift shaft is in the lowered position. With this configuration, the lift shaft is fixed in the lowered position, and the sealing performance of the shaft seal member is improved.

[0113] A sixth embodiment of the present invention is a sealing member (e.g., sealing member 3A) in any of the first to fifth embodiments, wherein the first mounting member (e.g., first mounting member 34) comprises a ring-shaped bottom portion (e.g., bottom portion 34a) adjacent to the upper end of the bellows cylindrical body, a wall portion (e.g., peripheral wall portion 34b) extending upward from the outer edge of the bottom portion, and a flange portion (e.g., flange portion 34c) having an outer diameter larger than the outer diameter of the bellows cylindrical body and protruding outward from the upper end of the wall portion in the radial direction of the bottom portion. According to this configuration, the collar is disposed below the flange portion, so that the lift shaft rise As a result, the lift shaft rise Once locked into position (pump elevated), the head plate can be removed from the top open end.

[0114] A seventh embodiment of the present invention is a sealing member according to any one of the first to sixth embodiments, which comprises a movement restricting member (e.g., movement restricting member 90) that restricts movement of the lift shaft above the raised position. According to this configuration, the bellows cylindrical body is not stretched excessively, and defects such as breakage of the bellows cylindrical body or welded portions do not occur.

[0115] An eighth embodiment of the present invention is a submerged pump system comprising a pump immersed in a pumped liquid, a cylindrical pump column accommodating the pump, and a sealing member according to any one of the first to seventh embodiments. According to this configuration, the bellows member can prevent the residual gas from leaking when the pump is raised and lowered. [Explanation of symbols]

[0116] 1 Submerged Pump System 2 Pump column 3 Sealing member 5. Pump 10 Head Plate 10a top surface 11 Insertion hole (through hole) 11a 1st hole 11b 2nd hole 11d bottom 20 Lift shaft 21 First shaft 21b Upper end surface 21c Lower end surface 22 Second shaft 30 Bellows member 31 Bellows cylinder 31a top end 31b Bottom end 32 First mounting member 33 Second mounting member 40 Upper seal member 50 Lower seal member 60 Shaft seal member 80 Shaft fixing member 90 Movement restriction member Lg liquefied gas (liquid handled) 3A Sealing member 30A bellows member 34 First mounting member (shaft fixing member) 34a bottom 34b Peripheral wall (wall) 34c flange

Claims

1. A sealing member that seals an open end of a cylindrical pump column that houses a pump that is immersed in a pumped liquid, and that suspends and supports the pump when the pump is raised and lowered within the pump column, a head plate having a through hole extending in the vertical direction and attached to the opening end so as to close the opening end; a lift shaft disposed through the through hole and raised and lowered between a raised position and a lowered position when the pump is raised and lowered; a bellows member that expands and contracts in the axial direction of the lift shaft in response to the lift shaft being raised and lowered; a shaft seal member disposed between the lift shaft and the head plate; and The bellows member is a bellows cylinder that covers an outer peripheral surface of a protruding portion of the lift shaft that protrudes upward from the head plate; a first mounting member disposed continuously with an upper end of the bellows cylindrical body and attached to an upper end surface of the lift shaft; a second mounting member disposed continuously with the lower end of the bellows cylindrical body and attached to the upper surface of the head plate; Equipped with The lift shaft A first shaft portion; a second shaft portion having an outer diameter smaller than an outer diameter of the first shaft portion, disposed below the first shaft portion, and inserted into the through hole; Equipped with The through hole is a first hole portion into which a lower portion of the first shaft portion is inserted when the lift shaft is located at the lowered position; a second hole portion having an inner diameter smaller than an inner diameter of the first hole portion, disposed below the first hole portion, and through which the second shaft portion is inserted; Equipped with The shaft seal member is disposed between a lower end surface of the first shaft portion and a bottom surface of the first hole portion. Sealing member.

2. an upper seal member disposed between the first mounting member and the upper end surface of the lift shaft; a lower seal member disposed between the second mounting member and the upper surface of the head plate; consisting of The sealing member according to claim 1 .

3. a shaft fixing member that fixes the lift shaft in the lowered position, When the lift shaft is in the lowered position, the shaft fixing member presses the lift shaft toward the head plate via the first mounting member. The sealing member according to claim 1 or 2.

4. A housing that accommodates the first shaft portion and the bellows cylinder body when the lift shaft is in the lowered position; and The first mounting member is a ring-shaped bottom portion attached to the upper end surface of the lift shaft and adjacent to the upper end of the bellows cylindrical body; a wall portion extending upward from the outer edge of the bottom portion; a flange portion having an outer diameter larger than an outer diameter of the bellows cylindrical body and projecting outward from an upper end of the wall portion in a radial direction of the bottom portion; Equipped with the flange portion is disposed above the housing, When the lift shaft is in the lowered position, the flange portion is fastened to the housing, and the first mounting member functions as the shaft fixing member. The sealing member according to claim 3 .

5. a movement restricting member that restricts movement of the lift shaft above the raised position, The sealing member according to any one of claims 1 to 4.

6. a pump immersed in the handled liquid; a cylindrical pump column that houses the pump; The sealing member according to any one of claims 1 to 5, consisting of Submerged pump system.

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