JP4909751B2 - Low temperature liquefied gas storage tank and manufacturing method thereof - Google Patents

Description

  The present invention relates to a low-temperature liquefied gas storage tank and a method for producing the same, and more specifically, stores low-temperature liquefied gas such as liquefied argon, liquefied oxygen, liquefied nitrogen, liquefied carbon dioxide gas, and liquefied natural gas (LNG). The present invention relates to a structure of a large-sized low-temperature liquefied gas storage tank disposed at a predetermined site for supplying various gases to a sterile room, a ventilator, or the like in a medical institution such as a hospital, and a manufacturing method thereof.

A large-sized low-temperature liquefied gas storage tank for storing low-temperature liquefied gas is generally formed in a double structure of an inner tank and an outer tank in order to suppress evaporation of the stored low-temperature liquefied gas. Forms a vacuum heat insulating layer filled with a heat insulating material such as pearlite and evacuated (see, for example, Patent Document 1).
Japanese Patent No. 2964310

  In recent years, it has been desired to increase the size of low-temperature liquefied gas storage tanks, but the maximum capacity is limited by various restrictions when transporting low-temperature liquefied gas storage tanks manufactured at the factory to the installation location, especially weight restrictions on public roads. The fact is. It is also possible to manufacture a large-scale low-temperature liquefied gas storage tank locally, but it is necessary to prepare a lot of equipment and equipment necessary for manufacturing, and the cost of the construction is significant due to prolonged construction work. Up is inevitable.

  Therefore, an object of the present invention is to provide a low-temperature liquefied gas storage tank that can reduce the weight during transportation, enable transportation on public roads, and minimize the increase in production cost, and a method for manufacturing the same.

  In order to achieve the above object, the low-temperature liquefied gas storage tank of the present invention is a low-temperature liquefied gas storage tank having an inner tank for storing a low-temperature liquefied gas and an outer tank provided outside the inner tank via a heat insulating layer. The outer tank is divided into an outer tank lower member and an outer tank upper member, the outer tank lower member and the inner tank are assembled, and a pipe communicating with the inner tank is passed through the outer tank lower member. By providing, the inner tank unit is integrally formed, and the outer tank upper member of the outer tank is joined and integrated with the upper part of the outer tank lower member of the inner tank unit at the storage tank installation location.

Furthermore, the low-temperature liquefied gas storage tank of the present invention includes a vacuuming pipe for evacuating the heat insulation layer or a gas inflow pipe for allowing gas to flow into the heat insulation layer in the outer tank upper member. It is characterized by being.

  The method for producing a low-temperature liquefied gas storage tank of the present invention is a method for producing a low-temperature liquefied gas storage tank having an inner tank for storing a low-temperature liquefied gas and an outer tank provided outside the inner tank via a heat insulating layer. The outer tank is divided into an outer tank lower member and an outer tank upper member, the outer tank lower member and the inner tank are assembled, and a pipe communicating with the inner tank is provided through the outer tank lower member. As a result, the inner tank unit is integrally formed, the outer tank upper member and the inner tank unit are separately transported to the storage tank installation place, and the inner tank unit is installed at the storage tank installation place, The outer tank upper member is lifted above the tank unit, and the outer tank upper member is lowered toward the inner tank unit so that the inner tank of the inner tank unit is accommodated in the outer tank upper member. Joining the upper part of the outer tank to the upper part of the lower part of the tank It is characterized by integrating Te.

In the method for manufacturing a low-temperature liquefied gas storage tank of the present invention, the inner tank unit and the outer tank upper member are joined and integrated, and then the heat insulating layer between the inner tank and the outer tank is evacuated. The heat insulating layer is filled with a heat insulating material, and further, the heat insulating material is filled by evacuating the heat insulating layer, and a gas is introduced into the heat insulating layer in a substantially vacuum state from the top of the heat insulating layer. The heat insulating material is densely filled in the heat insulating layer by repeatedly pressing the heat insulating material toward the lower portion of the heat insulating layer by the impact of the gas that flows in rapidly.

  According to the present invention, the cryogenic liquefied gas storage tank is divided and formed into the inner tank unit and the outer tank upper member of the outer tank, so that the weight limit during transportation can be cleared, and the cryogenic liquefaction larger than the conventional one can be cleared. Gas storage tanks can be manufactured. Moreover, an inner tank can be reliably supported by supporting an inner tank support leg with a storage tank support leg via an outer tank lower member bottom plate part. Further, by providing a guide member for preventing contact between the outer tank upper member and the inner tank, when the outer tank upper member is assembled to the inner tank unit at the storage tank installation location, the outer tank upper member and the inner tank It is possible to prevent the piping from being damaged.

  Furthermore, by providing a hanging tool on the outer tub upper end plate, the outer tub upper member can be increased in diameter by eliminating a member protruding from the outer periphery of the outer tub upper member. By providing an operation member capable of releasing the engagement from the lower part of the storage tank, the hanging tool can be removed from the ground, and work at a high place can be eliminated.

  FIG. 1 is an explanatory view showing an embodiment of the low-temperature liquefied gas storage tank of the present invention, FIG. 2 is a partially sectional front view showing an embodiment of the low-temperature liquefied gas storage tank in a completed state, and FIG. FIG. 4 is a plan view of the low-temperature liquefied gas storage tank, FIG. 5 is a front view of the main part of the low-temperature liquefied gas storage tank, and FIG. 6 is an explanatory view showing an installation example of various pipes.

  The low-temperature liquefied gas storage tank 11 has a cylindrical inner tank 12 for storing a low-temperature liquefied gas, and a cylindrical outer tank 14 provided outside the inner tank 12 via a heat insulating layer 13. The heat insulating layer 13 is filled with a powdery or granular heat insulating material such as pearlite and is evacuated to obtain a predetermined heat insulating property.

  In the storage tank manufacturing factory, the outer tank 14 is divided into an outer tank upper member 15 composed of an outer tank body 15a and an outer tank upper end plate 15b, and an outer tank lower member 16 composed of an outer tank lower end plate. The lower member 16 is assembled with the inner tank 12 and becomes a part of the inner tank unit 17. The inner tank 12 and the outer tank lower member 16 are assembled to the upper surface of the bottom of the outer tank lower member 16 by an inner tank support leg 18 that joins the bottom of the inner tank 12 and the inner bottom of the outer tank lower member 16. The inner tank support leg 18 is disposed in consideration of the position of the storage tank support leg 19 provided on the bottom lower surface of the outer tank lower member 16, and the inner tank support leg 18 is interposed via the bottom plate portion of the outer tank lower member 16. The tank support leg 19 can support 18 loads.

  Further, as shown in FIG. 6, the inner tank 12 has various pipes 20 such as a liquid feeding pipe, a lower liquid inlet pipe, an upper liquid inlet pipe, a gas discharge pipe, a test pipe, a liquid level gauge pipe, and the like. These pipes 20 are respectively disposed in a state of airtightly penetrating the outer tank lower member 16 when the inner tank unit 17 is formed. Furthermore, a suspension fitting 12 a is provided at the top of the inner tank 12.

  On the other hand, the outer tank upper member 15 is provided with a vacuuming pipe 21 for evacuating the heat insulating layer 13. The evacuation pipe 21 has a length corresponding to substantially the entire height of the outer tank body 15a, and a plurality of suction ports 21a are provided at predetermined positions. Further, a safety device / heat insulating material charging portion 22 is provided at the top of the outer tank upper end plate 15b, and suspension fittings 23 are provided at four locations on the outer surface of the outer tank body portion 15a.

  When the entire low-temperature liquefied gas storage tank is manufactured integrally in the factory, the vacuuming pipe 21 is usually provided through the outer end plate of the outer tank, but the vacuuming pipe 21 communicates with the inner tank 12. Since it is not a pipe to be used, it can be provided at an arbitrary position. Therefore, as shown in FIG. 6, by attaching the evacuation pipe 21 to the outer tank upper member 15 which is lighter than the inner tank unit 17, there is an advantage that the weights of both can be equalized during transportation.

  On the other hand, as shown in FIG. 7, a structure may be adopted in which the vacuum evacuation pipe 21 is attached to the inner tank unit 17 and the outer tank lower member 16 is penetrated and taken out. There is a merit that the piping can be concentrated on the bottom plate of the tank.

  It should be noted that both the members 15 and 16 are reliably specified at the joint between the outer tub upper member 15 and the outer tub lower member 16, that is, at the lower end of the outer tub upper member 15 and the upper end of the outer tub lower member 16. A jig (not shown) for joining in the state is provided so that the verticality of the welding allowance 14a and the outer tank upper member 15 when assembling and welding the two members 15 and 16 can be secured. Yes.

  The inner tank unit 17 manufactured in the factory and the outer tank upper member 15 are separately transported to the storage tank installation location. When loading / unloading to a transport vehicle or the like, the inner tank unit 17 uses the hanging metal fittings 12a and the inner tank supporting legs 18, and the outer tank upper member 15 uses the four hanging metal fittings 23 to lie down. As a crane. Thus, by dividing and forming the inner tank unit 17 and the outer tank upper member 15, the weight limit during public road transportation can be cleared (see FIG. 1A).

  At the storage tank installation place, first, the inner tank unit 17 is erected and installed at a predetermined position, and then the outer tank upper member 15 is lifted above the inner tank unit 17, and the outer tank upper member 15 is moved to the inner tank 12. The outer tank upper member 15 is lowered in the vertical direction toward the inner tank unit 17 so as to cover from above, that is, the inner tank 12 of the inner tank unit 17 is accommodated in the outer tank upper member 15 (see FIG. 1 (B)), the lower end of the outer tank upper member 15 and the upper end of the outer tank lower member 16 are welded to complete the outer tank 14 (see FIG. 1C). At this time, the inner tank unit 17 and the outer tank upper member 15 are reliably assembled by providing guide rollers or the like at appropriate positions inside the outer tank upper member 15 or outside the inner tank 12. The possibility of damaging the inner tank 12, the outer tank upper member 15, and the pipe 20 is eliminated.

  Next, the safety device of the safety device and heat insulating material charging part 22 attached to the top of the outer tank is removed, and the space between the inner tank 12 and the outer tank 14 constituting the heat insulating layer 13 from the safety device and heat insulating material charging part 22 In addition, the heat insulating material is fed into the heat insulating layer 13 and the vacuum evacuation pipe 21 having a length corresponding to substantially the entire height of the outer tank body 15a connected to the vacuum exhaust device is evacuated. When the insulation is completely charged, replace the safety device.

  In this way, the low-temperature liquefied gas storage tank 11 is divided and formed at the factory, and transported separately to the storage location and then assembled on-site, the weight restrictions can be greatly relaxed, and the large-sized low-temperature liquefied gas has a larger capacity than before. The storage tank 11 can be manufactured. And since the inner tank 12 which stores low temperature liquefied gas is completed in a factory including piping, the same airtight performance as the past can be obtained reliably, and a field test and inspection can be omitted. Moreover, since the outer tank 14 only needs to confirm the airtight state in the welding part of the outer tank upper member 15 and the outer tank lower member 16, the work in a field is hardly prolonged.

  In addition, the outer tank upper member 15 is significantly lighter than the total weight of the low-temperature liquefied gas storage tank completed at the factory, so that compared with the hanging metal fittings provided on the outer surface of the conventional finished low-temperature liquefied gas storage tank. Thus, the hanging bracket 23 can be reduced in size. Furthermore, the upper suspension fitting 23 is moved from the outer peripheral surface of the trunk portion to the upper surface of the outer tub upper end plate 15b, and a jig is attached to the lower end portion of the outer tub upper member 15 in place of the lower suspension fitting 23 to hang it up. By forming the outer tank body 15a, the outer tank body 15a can be increased in diameter up to the projecting dimension of the hanging metal fitting 23 with respect to the lateral width limitation during transportation, and the capacity of the low-temperature liquefied gas storage tank 11 can be increased. it can.

  FIGS. 8 to 13 show countermeasures for preventing the outer tank upper member from coming into contact with the inner tank or the pipe and damaging them when the outer tank upper member is assembled to the inner tank unit installed at a predetermined position. An example is given.

  First, FIG.8 and FIG.9 shows the one example which provided the some guide member so that attachment or detachment was possible in the lower end part circumferential direction of the outer tank upper member, FIG. 8 is a general view and FIG. 9 is an example of a guide member. FIG. The guide member 31 shown in this embodiment includes a mounting portion 32 for detachably mounting on the peripheral wall of the outer tub upper member 15 and a guide portion 33 protruding from the mounting portion 32 in the inner peripheral direction of the outer tub upper member 15. And is formed. The mounting portion 32 utilizes a so-called giant clam vise structure, and is formed of a C-shaped or U-shaped fixing portion 32a and a screw member 32c screwed into one arm portion 32b of the fixing portion 32a. The outer tank upper member 15 is attached to the lower end of the outer tub upper member 15 by sandwiching the peripheral wall of the outer tub upper member 15 between the other arm portion 32d of the fixing portion 32a and the clamping member 32e provided at the tip of the screw member 32b. The guide portion 33 is formed such that a guide rod 33c provided with a roller 33b is inserted in an insertion hole 33a provided in the mounting portion 32 so as to be movable in the axial direction, and the guide rod 33c is fixed at a predetermined position by a set screw 33d. Has been.

  Therefore, the guide member 31 adjusts the protruding amount of the guide bar 33c in a state in which the guide member 31 is attached to the lower end of the peripheral wall of the outer tank upper member 15 by the mounting portion 32, whereby the inner peripheral surface of the outer tank upper member 15 is adjusted. The protrusion length L from the roller 33b to the tip of the roller 33b can be set according to the distance between the inner peripheral surface of the outer tub upper member 15 and the outer peripheral surface of the inner tub 12. In addition, the entire guide rod 33c or the tip thereof is made of a material having flexibility and low friction, for example, a synthetic resin, so that the inner tank 12 is not damaged even if the guide bar 33c contacts the inner tank 12. It is preferable to form by etc. The guide rod 33c may be a rod-shaped one without attaching the roller 33b to the tip, but if the guide rod 33c is made of metal, a cloth or a cushion material is attached to the tip of the guide rod 33c during work. Thus, damage to the inner tank 12 can be prevented.

  By arranging the guide members 31 formed in this manner at a plurality of locations in the circumferential direction at the lower end of the outer tank upper member 15, the outer tank upper member 15 is lifted above the inner tank unit 17 as shown in FIG. When the outer tank upper member 15 is lowered so as to cover the inner tank 12 from above, even if the suspended outer tank upper member 15 is slightly shaken by the wind, the roller 33b is spherical on the upper end plate 12b of the inner tank 12 The position of the lower end opening of the outer tank upper member 15 can be guided to the upper part of the inner tank 12 by contacting the outer surface. Therefore, the outer tank upper member 15 can be reliably lowered to a predetermined position, and the outer tank upper member 15 can be easily assembled. Further, by removing the guide member 31 from the lower end of the outer tank upper member 15 when the lower end of the outer tank upper member 15 is lowered near the upper end of the outer tank lower member 16, the outer tank upper member 15 and the outer tank lower member 16 are removed. Can be joined with no problem.

  The number and position of the guide members 31 attached are the height, weight and diameter of the outer tank upper member 15, the strength of the guide member 31, the buffer effect, the position of each pipe 20 provided in the inner tank unit 17, and the time of work. It is sufficient to set according to conditions such as wind power, and it is usually sufficient to provide three guide members 31 at equal intervals in the circumferential direction. Further, by connecting the guide rope to the guide member 31, the outer tank upper member 15 can be more reliably guided by the guide rope.

  10 to 13 show an embodiment in which a plurality of guide members are provided on the inner peripheral surface of the outer tank upper member, FIG. 10 is a partially sectional front view, and FIGS. 11 to 13 are structures of the guide members. It is a front view which shows an example.

  The guide member 41 shown in this embodiment is for preventing contact between the inner peripheral surface of the outer tank upper member and the outer peripheral surface (including piping) of the outer tank upper member due to the shaking of the outer tank upper member 15. A plurality of outer tank upper members 15 are provided in each of the height direction and the circumferential direction. The protruding dimension of each guide member 41 from the inner peripheral surface of the outer tank upper member 15 is set according to the distance between the inner peripheral surface of the outer tank upper member 15 to which the guide member 41 is attached and the outer peripheral surface of the inner tank 12. As described above, the tip of the guide member 41 is made of a material having flexibility and low friction that does not damage the inner tub 12 even if it contacts the outer peripheral surface of the inner tub 12.

  As shown in FIG. 11, a short tube 42a is fixed to the guide member 41 on the inner peripheral surface of the outer tank upper member 15, and a tip member 42b made of a synthetic resin having a low thermal conductivity is attached to the short tube 42a. 12, a roller 43b rotatably provided on a bearing member 43a fixed to the inner peripheral surface of the outer tub upper member 15, as shown in FIG. A rotating member 44b having a tip member 44a made of synthetic resin or the like can be used such that it can be bent only upward at the tip of a fixing member 44c fixed to the inner peripheral surface of the outer tank upper member 15. .

  A total of six such guide members 41 are provided in a plurality of locations in the height direction and the circumferential direction of the outer tank upper member 15, for example, two locations in the height direction and three locations in the circumferential direction at each height position. Thus, the outer tank upper member 15 can be smoothly lowered along the outer peripheral surface of the inner tank 12. Such a guide member 41 can also be used as a steady stop for the inner tank 12. The position of the guide member 41 can be set to an arbitrary position that can achieve these predetermined purposes, and the height position and the circumferential position may be shifted. Further, the guide member 41 can be used in combination with the guide member 31 shown in FIG. 8. When the guide member 31 is provided at the lower end of the outer tank upper member 15, the guide member 41 shown in this embodiment is used. It is only necessary to provide a plurality of members in one place on the upper side in the height direction of the outer tank upper member 15, for example, in the circumferential direction at the intermediate height position.

  FIG. 14 and FIG. 15 show an embodiment in which the heat insulating material is filled into the heat insulating layer between the inner tank and the outer tank from the lower part of the storage tank, FIG. 14 is a schematic front view, and FIG. It is a top view.

  In the present embodiment, as a pipe for filling the heat insulating material into the heat insulating layer 13 from the lower part of the storage tank, the lower part of the outer tank lower member 15 passes through the lower part of the outer tank lower member 15 to reach the upper part of the heat insulating layer. A heat-insulating material filling pipe 51 and a gas inflow pipe 52 for opening gas into the uppermost part of the heat insulating layer by opening in the outer tank upper end plate 15b of the outer tank upper member 15 are provided. As shown in FIG. 15, a plurality of, for example, two heat insulating material filling pipes 51 are provided, and the front end openings 51a of the respective heat insulating material filling pipes 51 opened at the uppermost part of the heat insulating layer are directed in different directions. Is arranged. Further, on / off valves 21V, 51V, and 52V are provided on the outside of the storage tank of the evacuation pipe 21, the heat insulating material filling pipe 51, and the gas inflow pipe 52, and the heat insulating layer 13 is opened and closed by opening and closing each of the on / off valves. The inside is filled with a heat insulating material at a predetermined filling density.

  After the outer tank upper member 15 is joined and integrated with the inner tank unit 17, the on-off valve 21V of the evacuation pipe 21 and the on-off valve 51V of the heat insulating material filling pipe 51 are opened, and a vacuum exhaust device (not shown) is operated. The inside of the heat insulating layer 13 is evacuated by the evacuation pipe 21, and the heat insulating material is sucked by the heat insulating material filling pipe 51 to supply the heat insulating material into the heat insulating layer 13. At this time, a plurality of heat insulating material filling pipes 51 are provided, and at the position where the tip opening 51a of each heat insulating material filling pipe 51 is disengaged from the top of the inner tank 12, the charging direction of the heat insulating material from the tip opening 51a is different, for example, By opening the tip openings 51 a of the two heat insulating material filling pipes 51 in the opposite directions, it is possible to prevent the heat insulating material from accumulating in the upper part of the inner tank 12, and to put the heat insulating material in a wide range of the heat insulating layer 13. be able to. Further, a plurality of vacuuming pipes 21 are provided, and the vacuuming pipes 21 and the front end openings 51a of the heat-insulating material filling pipes 51 are alternately arranged at equal intervals in a plan view. Thus, the gas flow in the heat insulating layer 13 sucked into the heat insulating layer 13 can be equalized, and the entire heat insulating layer 13 can be averagely filled with the heat insulating material.

  Then, after filling the heat insulating material to some extent, the on-off valve 51V is closed and then the on-off valve 21V is closed, and then the on-off valve 52V of the gas inflow pipe 52 is opened to form a heat insulating layer in the heat insulating layer 13 which is in a substantially vacuum state. A gas such as air or nitrogen is supplied into the heat insulating layer 13 from the top of 13 at a stretch. Thereby, the heat insulating material in the heat insulating layer 13 is pressed toward the lower side of the heat insulating layer 13 by the impact of the gas rapidly flowing into the heat insulating layer 13. By appropriately repeating such filling of the heat insulating material by evacuation and pressing of the heat insulating material with gas, the heat insulating material can be densely filled in the heat insulating layer 13.

  In addition, when a heat insulating material is charged into the heat insulating layer 13 from the safety device / heat insulating material charging portion 22, a high place work by an operator is necessary. In addition to the vacuuming pipe 21, the heat insulating material filling pipe 51 is used. And the gas inflow pipe 52 allow the charging and filling of the heat insulating material to be performed by work on the ground or near the ground, and work at high places is not necessary. In this embodiment, the heat insulating material filling pipe 51 is provided on the inner tank unit 17 side, but may be provided on the outer tank upper member 15 side. Further, the gas inflow pipe 52 can be provided outside the outer tank upper member 15, but by passing the inner side of the outer tank upper member 15, it is possible to eliminate protrusions to the outer peripheral side.

  FIGS. 16 and 17 show an embodiment in which a hanging bracket is provided on the outer tank upper end plate of the outer tank upper member, FIG. 16 is a front view of the main part, and FIG. 17 is an engagement of the lifting tool and the hanging bracket. It is explanatory drawing which shows the operation procedure which cancels | releases.

  The hanging metal fitting 61 shown in the present embodiment is provided in a state protruding above the outer tank upper end plate 15b of the outer tank upper member 15 and within the outer diameter range of the outer tank upper member 15, The base member 61a is fixed to the upper surface of the upper end plate 15b, and the circular brazing member 61c is provided on the vertical surface 61b of the base member 61a. The outer tank upper member 15 is lifted at the storage tank installation place by engaging a ring-shaped suspension rope 63 with a guide rope 62 attached in advance to the brazing member 61c of the suspension fitting 61, and the outer tank upper member 15 in a laid state is laid down. Is lifted by a crane via a ring-shaped suspension rope 63, and after standing in the vertical direction, the outer tank upper member 15 is lowered toward the inner tank unit 17.

  As shown in FIG. 17A, after the joining operation of the inner tub unit 17 and the outer tub upper member 15 is completed, the ground worker 64 holds the lower portion of the guide rope 62 in the state shown in FIG. As shown in FIG. 17C, the ring-shaped suspension rope 63 is lowered and the guide rope 62 is pulled, so that the ring-shaped suspension rope 63 can be removed from the bracing member 61c as shown in FIG. Therefore, a high place work for removing the ring-shaped suspension rope 63 from the suspension fitting 61 becomes unnecessary.

  Moreover, the above-mentioned suspension metal fitting 23 protrudes from the outer tank trunk | drum 15a by projecting the suspension metal fitting 61 above the outer tank upper end plate 15b and arranging it within the outer diameter range of the outer tank upper member 15. Compared to the case, the outer tank 14 can be enlarged in diameter, and the low-temperature liquefied gas storage tank 11 can be further enlarged. Furthermore, the suspension fitting provided in the inner tub 12 can be provided with the same shape as that of the suspension fitting 61 on the top portion or the side of the trunk portion of the inner tub 12, and the removal of the ring-shaped suspension rope 63 is guided in the same manner as described above. By performing the operation with the rope 62, it is possible to eliminate the work at a high place when the inner tank unit 17 is installed. In addition, although a ring-type suspension rope is generally used for the hanging tool, other hanging tools can also be used. The operation member capable of releasing the engagement between the hanging tool and the hanging bracket is a simple guide rope, but an appropriate operation member can be used depending on the engagement state between the hanging tool and the hanging bracket. .

  In addition, the material and shape of each member are not specifically limited, It can be made the same as that of the conventional low temperature liquefied gas storage tank. Also, manufacturing in the factory can be performed in the same procedure except that the outer tank 14 is divided into the outer tank upper member 15 and the outer tank lower member 16, and the existing facilities in the factory are significantly changed. There is no need. Furthermore, although the division position of the outer tub 14 is the boundary position between the outer tub lower end plate and the outer tub trunk in the present embodiment, it may be divided below the outer tub trunk.

It is explanatory drawing which shows one example of the low temperature liquefied gas storage tank of this invention. It is a partial cross section front view which shows one example of the low temperature liquefied gas storage tank of the completed state. It is a front view which shows the state which established the inner tank unit. It is a top view of a low-temperature liquefied gas storage tank. It is a front view of the principal part of a low-temperature liquefied gas storage tank. It is explanatory drawing which shows the example of installation of various piping. It is explanatory drawing which shows the example which attached piping for vacuuming to the inner tank unit. It is the whole figure which shows one form example which provided the some guide member so that attachment or detachment was possible in the lower end part circumferential direction of an outer tank upper member. It is a front view which similarly shows an example of a guide member. It is a partial cross section front view which shows the one example which provided the some guide member in the internal peripheral surface of an outer tank upper member. It is a front view which similarly shows the structural example of a guide member. It is a front view which similarly shows the other structural example of a guide member. It is a front view which shows the other structural example of a guide member similarly. It is a schematic front view which shows the example of a form which was able to perform the filling of the heat insulating material to the heat insulation layer between an inner tank and an outer tank from the storage tank lower part. Similarly, it is a schematic plan view. It is a front view of the principal part which shows the example which provided the suspension metal fitting in the outer tank upper end panel of the outer tank upper member. It is explanatory drawing which shows the operation procedure which cancels | releases engagement with a hanging tool and a hanging metal fitting.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Low temperature liquefied gas storage tank, 12 ... Inner tank, 12a ... Hanging metal fitting, 12b ... Upper end plate, 13 ... Thermal insulation layer, 14 ... Outer tank, 14a ... Welding allowance, 15 ... Outer tank upper member, 15a ... Outer tank trunk 15b ... Outer tank upper end panel, 16 ... Outer tank lower member, 17 ... Inner tank unit, 18 ... Inner tank support leg, 19 ... Storage tank support leg, 20 ... Pipe, 21 ... Vacuum suction pipe, 21a ... Suction port, DESCRIPTION OF SYMBOLS 22 ... Safety device and heat insulating material injection | throwing-in part, 23 ... Suspension metal fitting, 31 ... Guide member, 32 ... Mounting part, 32a ... Fixing part, 32b ... Arm part, 32c ... Screw member, 32d ... Arm part, 32e ... Clamping member 33 ... Guide portion, 33a ... Insertion hole, 33b ... Roller, 33c ... Guide rod, 33d ... Set screw, 41 ... Guide member, 42a ... Short tube, 42b ... Tip member, 43a ... Bearing member, 43b ... Roller, 44a ... Tip member, 44b ... Rotating member, 44c Fixing member, 51 ... heat insulating material filling pipe, 51a ... tip opening, 52 ... gas inflow pipe, 61 ... suspension fitting, 61a ... base member, 61b ... vertical surface, 61c ... brazing member, 62 ... guide rope, 63 ... ring Type hanging rope, 64 ... Worker, 21V, 51V, 52V ... Open / close valve

Claims (6)

In a low-temperature liquefied gas storage tank having an inner tank for storing the low-temperature liquefied gas and an outer tank provided outside the inner tank via a heat insulating layer, the outer tank is divided into an outer tank lower member and an outer tank upper member. The outer tank lower member and the inner tank are assembled, and an inner tank unit is integrally formed by providing a pipe communicating with the inner tank through the outer tank lower member. The low temperature liquefied gas storage tank characterized in that the outer tank upper member is joined and integrated with the upper part of the outer tank lower member of the inner tank unit at the storage tank installation location. The low temperature liquefied gas storage tank according to claim 1, wherein the outer tank upper member is provided with a vacuuming pipe for evacuating the heat insulating layer. The low temperature liquefied gas storage tank according to claim 1, wherein the outer tank upper member includes a gas inflow pipe for allowing gas to flow into the heat insulating layer. In the manufacturing method of the low temperature liquefied gas storage tank which has the inner tank which stores low-temperature liquefied gas, and the outer tank provided in the outer side of the inner tank via the heat insulation layer, the outer tank is made into the outer tank lower member and the outer tank upper part. It is divided into members, and the inner tank unit is integrally formed by assembling the outer tank lower member and the inner tank, and providing a pipe communicating with the inner tank through the outer tank lower member, The outer tank upper member and the inner tank unit are separately transported to the storage tank installation location, and after installing the inner tank unit at the storage tank installation location, the outer tank upper member is lifted above the standing inner tank unit. The outer tank upper member is lowered toward the inner tank unit so that the inner tank of the inner tank unit is accommodated in the outer tank upper member, and the outer tank upper member is joined to the upper part of the outer tank lower member of the inner tank unit. Low temperature liquefaction, characterized by Manufacturing method of the scan storage tank. After the inner tank unit and the outer tank upper member are joined and integrated, the heat insulating layer between the inner tank and the outer tank is evacuated, and the heat insulating material is filled in the heat insulating layer. The manufacturing method of the low temperature liquefied gas storage tank of Claim 4. Filling the heat-insulating layer by evacuation and supplying the gas from the top of the heat-insulating layer into the heat-insulating layer in a substantially vacuum state. 6. The method for producing a low-temperature liquefied gas storage tank according to claim 5, wherein the heat insulating material is densely filled in the heat insulating layer by repeating the pressing toward the lower part.

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