TWI552935B - Tank roof opening method - Google Patents

Description

Opening method of storage tank roof

The present invention relates to a method of opening a roof of a tank in which a roof structure for storing a reservoir of liquefied gas is opened.

Liquefied gas systems such as liquefied natural gas (LNG) and liquefied petroleum gas (LPG) are stored in a storage tank in a low-temperature liquid state. The storage tank has a double-shell structure for maintaining a storage space inside the stored liquefied gas at a low temperature. That is, the double-shell structure is used to suppress heat from entering the storage space inside the tank from the outside of the tank.

Such a storage tank (hereinafter simply referred to as a storage tank) is described, for example, in Patent Document 1 below. The storage tank for storing the liquefied gas is a double-shell structure, and has an inner structure which has an inner surface which forms a storage space, and an outer structure which covers the inner structure from the outer side, as shown in the patent document 1. A heat insulating space is formed between the inner structure and the outer structure. In the heat insulating space, in order to suppress the conduction of heat from the outside of the storage tank to the storage space, a granular heat insulating material (for example, expanded perlite) is filled.

(previous technical literature) (Patent Literature)

Patent Document 1: Japanese Patent No. 3582241

The inner structural system of the tank has an inside roof. The outer side of the tank has a roof on the outside of the tank. The above-mentioned heat insulating space is formed between the inner roof and the outer roof.

In the existing storage tank, in order to check the state of the storage space (the liquid level of the liquefied gas, the temperature, the pressure, or the density of the liquefied gas), the roof structure of the storage tank (ie, the inner roof and the outer roof) may be considered. A through hole is opened, and an inspection machine (inspection nozzle) for inspecting the storage space is inserted into the storage space from the outside of the storage tank through the through hole.

However, between the inner roof and the outer roof, there is a heat insulating space for filling the granular heat insulating material.

Further, on the lower surface of the outer roof, a bone member extending radially from the central portion side of the roof of the tank is provided. Therefore, it is difficult to form a work area larger than the interval between the bone members (a region where a person performs an operation for arranging the inspection machine) between the inner roof and the outer roof.

Accordingly, it is an object of the present invention to provide a method for providing a method for a roof structure of a storage tank having a granular outer layer of a roof and an outer roof and a heat insulating space between the two. A working area of a plurality of spaced apart bone members disposed on a lower surface of the outer roof is formed between the inner roof and the outer roof.

In order to achieve the above object, according to an aspect of the present invention, there is provided a method for opening a roof of a tank in which a roof of a tank for storing a liquefied gas is internally opened, the tank having a storage space for storing a liquefied gas The roof system includes: an inner roof that covers an upper portion of the storage space; a roof that covers the outer roof from the upper side; and a granular heat insulating material that fills the heat insulating space between the inner roof and the outer roof; A plurality of bone members extending radially from a central portion side of the outer roof are attached to the lower surface of the outer roof, and the opening method of the roof includes: (A) an object surrounding the outer surface of the outer roof a region extending in a manner to form a plurality of slits divided by the portion so as to avoid a portion overlapping the bone member in a thickness direction of the outer roof, and each slit penetrates the outer roof in the thickness direction; Inserting a plurality of the rupture plates into the plurality of the aforementioned slits, respectively, forming a plurality of the foregoing in the heat insulating space (C) removing the granular material from the working area through the hole for filling the heat insulating material or the through hole for taking out the heat insulating material formed in the target area. The heat insulating material (D) is formed in the target region of the outer roof to open the outer side of the outer roof in the thickness direction; (E) In the work area, an inner opening of the storage space that communicates with the storage tank is formed on the inner roof.

According to the invention as described above, the plurality of slits divided by the portion are formed so as to surround the target region on the outer surface of the outer roof, and the portion overlapping the bone member in the thickness direction of the outer roof is avoided. A plurality of rupture plates are inserted into the slots. Thereby, a work area surrounded by a plurality of shutters can be formed between the outer roof and the inner roof.

Thus, by a plurality of slits arranged to avoid a plurality of bone members, a work area having a larger size than a plurality of bone members can be formed.

Then, the granular heat insulating material can be taken out from the work area, and the outer opening is formed in the object area of the outer roof, and in the work area, the inner side opening of the storage space connected to the storage tank is formed on the inner side roof.

3‧‧‧ storage space

5‧‧‧The inner structure

5a‧‧‧Inside wall

5b‧‧‧ inside roof

5c‧‧‧ inside opening

7‧‧‧Outside structures

7a‧‧‧Outer side wall

7b‧‧‧Outer roof

7c‧‧‧Outside opening

9‧‧‧Insulation space

9a‧‧‧Working area

10‧‧‧ storage tank

11‧‧‧Under the outer roof surface

12‧‧‧Reinforcing components

13‧‧‧ bone members

15‧‧‧ Upper surface of the outer roof

17‧‧‧ Upper surface of the inner roof

19‧‧‧ slit

21‧‧‧through holes

23‧‧‧ 断板

23a‧‧‧Gap section

23b‧‧‧Outside part of the slab

25‧‧‧column components

25a‧‧‧The outer part of the column member

27‧‧‧ Ribs

29‧‧‧Waterproof board

31‧‧‧ Holes for insulation filling

33‧‧‧Check the machine

33a‧‧‧Fixed Department

33b‧‧‧Extension

33c‧‧‧Sensor Department

L1‧‧‧1st side

L2‧‧‧2nd side

L3‧‧‧3rd side

L4‧‧‧4th side

R0‧‧‧Target area

R1‧‧‧ gap area

Fig. 1A is a side view showing a reservoir which can be the object of the opening method of the roof of the tank of the present invention.

Figure 1B is a B-B arrow view of Figure 1A and shows the underside of the outside roof.

Fig. 2 is a flow chart showing a method of opening a roof of a storage tank according to an embodiment of the present invention.

Fig. 3A is a view of the arrow line III-III of Fig. 1A, and is a view for explaining the sequence of the opening method of the roof of the tank.

Figure 3B is another diagram for explaining the sequence of the opening method of the roof of the tank.

Fig. 4A is a cross-sectional view taken along line IVA-IVA of Fig. 3B.

Figure 4B corresponds to the diagram of Figure 4A.

Fig. 5A is an explanatory diagram corresponding to step S2 of Fig. 3B.

Fig. 5B is an explanatory diagram corresponding to step S4 of Fig. 5A.

Fig. 6A is a cross-sectional view taken along line VIA-VIA of Fig. 5B.

Fig. 6B is a cross-sectional view taken along line VIB-VIB of Fig. 7B.

Fig. 7A is an explanatory diagram corresponding to step S5 of Fig. 5B.

Fig. 7B is an explanatory diagram corresponding to step S7 of Fig. 7A.

Fig. 8A is an explanatory diagram corresponding to step S9 of Fig. 6B.

Fig. 8B is an explanatory diagram corresponding to step S10 of Fig. 8A.

Embodiments of the present invention will be described with reference to the drawings. In addition, the same components are denoted by the same reference numerals throughout the drawings, and the description thereof will be omitted.

The storage tank which is the object of the opening method of the roof of the tank of the present invention will be described based on Figs. 1A and 1B.

Fig. 1A shows the side of the reservoir 10 which is the object of the opening method of the roof of the tank of the present invention. Fig. 1B is a view taken along the line B-B of Fig. 1A, and shows the lower surface of the outer roof 7b which will be described later. Further, in Fig. 1B, the illustration of the inner roof 5b is omitted.

The storage tank 10 has a storage space 3 for storing liquefied gas inside. The liquefied gas is a liquefied natural gas or a liquefied petroleum gas. The storage tank 10 is a double-shell structure and includes an inner structure 5 having an inner surface forming the storage space 3 and an outer structure 7 covering the inner structure 5 from the outer side. A heat insulating space 9 is formed between the inner structure 5 and the outer structure 7.

The inner structure 5 has an inner side wall 5a and an inner side roof 5b. The inner side wall 5a forms an inner peripheral surface of the storage space 3. The inner roof 5b is joined to the upper end portion of the inner side wall 5a. The inner roof 5b covers the upper portion of the storage space 3 in which the liquefied gas is stored.

The outer structure 7 has an outer side wall 7a and an outer side roof 7b. The outer side wall 7a extends in the circumferential direction so as to surround the inner side wall 5a. The outer roof 7b is coupled to the upper end of the outer side wall 7a. The outer roof 7b covers the inner roof 5b from above.

As shown in Fig. 1B, a plurality of (for example, a plurality of) bone members 13 extending radially from the central portion side of the outer roof 7b are attached to the lower surface 11 of the outer roof 7b. Each of the bone members 13 protrudes from the lower surface 11 of the outer roof 7b toward the lower side and in the thickness direction of the outer roof 7b. Further, as shown in Fig. 1B, a reinforcing member 12 extending in the circumferential direction of the outer roof 7b is also attached to the lower surface 11 of the outer roof 7b.

A heat insulating space 9 is formed between the inner structure 5 and the outer structure 7. The heat insulating space 9 is filled with a granular heat insulating material. The granular heat insulating material is a granular expanded perlite in the present embodiment. In addition, the expansive perlite system smashes obsidian, perlite, rosin, etc. And quickly make it heated and expanded.

The roof structure of the storage tank 10 is constituted by the inner roof 5b, the outer roof 7b, and the granular heat insulating material filled in the heat insulating space 9 between the inner roof 5b and the outer roof 7b.

The central portion of the upper surface 15 of the outer roof 7b is as shown in Fig. 1A, and is higher than the outer periphery of the upper surface 15 of the outer roof 7b. The upper surface 15 of the outer roof 7b gradually becomes lower as it is transferred from the central portion of the outer roof 7b to the outer periphery of the outer roof 7b. Similarly, the central portion of the upper surface 17 of the inner roof 5b is higher than the outer periphery of the upper surface 17 of the inner roof 5b. The upper surface 17 of the inner roof 5b gradually decreases as it moves from the central portion of the inner roof 5b to the outer periphery of the inner roof 5b.

Figure 2 is a flow chart of the opening method of the roof of the tank.

Next, a method of opening the roof of the tank in which the roof of the tank 10 is opened will be described with reference to Fig. 2 and other figures.

Figure 3A is a view of the arrow line III-III of Figure 1A and showing a portion of the upper surface 15 of the outer roof 7b.

In step S1, as shown in FIG. 3A, the object region R0 (the region surrounded by a little chain line in FIG. 3A) in the upper surface 15 of the outer roof 7b is extended so as to avoid A plurality of slits 19 divided by the portion are formed in such a manner that the thickness direction of the outer roof 7b overlaps with the bone member 13. Each of the slits 19 penetrates the outer roof 7b in the thickness direction of the outer roof 7b.

Further, the upper surface 15 of the outer roof 7b on which the target region R0 is set is inclined with respect to the horizontal plane.

In the target region R0, a hole (hole) 31 for filling the heat insulating material is positioned on the outer roof 7b. The hole 31 for heat insulating material filling can be opened and closed. The heat insulating material filling hole 31 in the open state communicates the outside of the storage tank 10 with the heat insulating space 9 between the inner roof 5b and the outer roof 7b. The heat insulating material 9 can be supplied with a heat insulating material or the heat insulating material can be taken out from the heat insulating space 9 by the heat insulating material filling hole 31 in an open state.

In the present embodiment, the target region R0 is set so as not to overlap the reinforcing member 12 (see FIG. 1B) in the thickness direction of the outer roof 7b.

In the present embodiment, the target region R0 has a quadrangular shape (a trapezoidal shape in a preferred example). As shown in FIG. 3A, the square has a first side L1 extending in the horizontal direction, and a second side extending from the both ends of the first side L1 toward the lower side along the upper surface 15 of the outer roof 7b. The third side L2 and L3; and the fourth side L4 extending in the horizontal direction so as to connect the lower ends of the second and third sides L2 and L3.

In step S1, a slit 19 is formed in each of the first, second, third, and fourth sides L1, L2, L3, and L4.

Further, in the present embodiment, in the outer roof 7b, the position of the portion overlapping with the bone member 13 in the thickness direction of the outer roof 7b is avoided in the step S1, and the position adjacent to the slit 19 is adjacent. A through hole 21 for inserting a column member 25 to be described later is formed. In the example of Fig. 3A, the column member 25 to be described later has a U-shaped cross section, and thus a through hole 21 having a U shape is formed.

Next, the description of step S2 will be given.

Fig. 3B corresponds to the diagram of Fig. 3A (i.e., the view from the same direction, the same applies hereinafter), and is an explanatory diagram of step S2. Further, Fig. 4A is a cross-sectional view taken along line IVA-IVA of Fig. 3B, and is an explanatory view of step S2. Fig. 4B is also an explanatory diagram corresponding to step S2 of Fig. 4A. Fig. 5A is also an explanatory diagram corresponding to step S2 of Fig. 3B.

In step S2, as shown in Fig. 3B, a plurality of shutters 23 are inserted into the plurality of slits 19, respectively. Thereby, in the heat insulating space 9, the work area 9a surrounded by the plurality of shutters 23 is formed. At this time, each of the blocking plates 23 is formed from the outer portion 23b (refer to FIG. 4A described later) located above the upper surface 15 of the outer roof 7b, and extends downward in the thickness direction of the outer roof 7b. The lower end is in contact with the state of the upper surface 17 of the inner roof 5b. Further, each of the shutters 23 has a rectangular side surface.

In an example, as shown in FIG. 4A, one of the blocking plates 23 disposed on both sides of the bone member 13 so as to sandwich the bone members 13 is in contact with the inner roof 5b at the lower end. The region having the same height as the bone member 13 in the state of the upper surface 17 has a notch portion 23a recessed in the width direction Dw of the bone member 13. Further, Fig. 1B shows the width direction Dw of one bone member 13. In the example of Fig. 4A, the blocking plate 23 has a shape in which the corner portion of the rectangular side surface is cut in order to form the notch portion 23a.

At this time, first, as described above, in step S2, a plurality of shutters 23 are respectively inserted into the plurality of slits 19, and as shown in FIG. 4A, the lower ends of the shutters 23 are brought into contact with the inner side. Above the roof 5b After the surface 17, the respective blocking plates 23 having the notched portions 23a (hereinafter simply referred to as the notched blocking plates 23) are oriented in the width direction Dw of the bone members 13 adjacent to the notched blocking plates 23. Displacement (moving). Thereby, as shown in FIG. 4B, the bone member 13 and the portion in which the thickness direction of the outer roof 7b overlaps the bone member 13 on the outer side roof 7b are located in the notch portion 23a. Thereby, in the heat insulating space 9, the gap region 23 in which the thickness direction of the outer roof 7b is overlapped with the bone member 13 is closed by the partition plate 23 with the notch (the area surrounded by the broken line in FIG. 4A) . This state is shown in Fig. 4B and Fig. 5A.

In this manner, since the notch-blocking plate 23 is moved toward the width direction Dw of the bone member 13, and the bone member 13 is placed in the notch portion 23a, the gap-attached shutter can be used in the heat-insulating space 9. 23 is to close the region R1 which is overlapped with the bone member 13 in the thickness direction of the outer roof 7b. As a result, in the heat insulating space 9, the working area 9a having a higher degree of sealing with respect to the area of the other heat insulating space 9 can be formed.

Further, Fig. 4B shows the state of each of the slits 23 inserted into the slits 19 on the fourth side L4 of the target region R0, but the slits 19 inserted in the first side L1 of the target region R0. The shutter 23 is also the same as described above.

On the other hand, the second and third sides L2 and L3 of the target region R0 described above are not overlapped with the bone member 13 in the thickness direction of the outer roof 7b. Therefore, each of the blocking plates 23 inserted into the slits 19 on the second and third sides L2 and L3 does not have the above-described notch portion 23a.

Thus, in step S2, by masking the gap The breaking plate 23 is moved toward the width direction Dw of the bone member 13, and the other blocking plate is inserted so that the amount of movement becomes no longer in the longitudinal direction of the slit 19 of the blocking plate 23. This can also be carried out, for example, in the manner described below.

As shown in FIGS. 3B and 4A, in step S2, the notched shutter 23 and the other shutter 23 are inserted into the same slit in such a manner as to be partially repeated in the width direction of the slit 19. 19 (in FIG. 3B, each slit 19 on the first and fourth sides L1, L4). Then, as shown in, for example, FIGS. 4B and 5A, by moving the notched shutter 23 toward the width direction Dw of the bone member 13, the amount of movement up to the extent becomes the absence of the shutter 23 The length direction range of the slit 19 becomes such that the other shutter 23 described above is located there. Thereby, the shutter 23 can be present in the entire length direction of the slit 19.

In this way, by moving the notched shutter 23 toward the width direction Dw of the bone member 13, the length of the slit 19 of the shutter 23 having no gap is not increased, and the other is inserted. A shutter 23 is provided. Therefore, even if the shielding plate 23 with the notch is moved in the width direction Dw of the bone member 13, the shielding plate 23 can be present in the entire longitudinal direction of the slit 19.

Further, in the present embodiment, in step S2, as shown in Fig. 5A, the column member 25 is inserted into the through hole 21 formed in step S1.

Next, step S3 will be described.

In step S3, each of the shutters 23 is fixed to the outer roof 7b by welding. That is, each of the louvers 23 has a ratio of the outer side The outer portion 23b (see FIGS. 4A and 4B) above the upper surface 15 of the top portion 7b is fixed to the outer roof portion 7b by welding. At this time, the lower end of each of the shutters 23 is in contact with the upper surface 17 of the inner roof 5b.

Further, in step S3, the column member 25 (the outer portion 25a (refer to FIG. 6A to be described later) which is higher than the upper surface 15 of the outer roof 7b is fixed to the outer roof 7b by welding, and is inserted by welding. The shutter 23 of the slit 19 is fixed to the column member 25. At this time, the lower end of each column member 25 is in contact with the upper surface 17 of the inner roof 5b.

Since the column member 25 is provided as described above, the column member 25 is fixed to the outer roof 7b, and the shutter 23 is fixed to the column member 25, the shutter 23 is reinforced by the column member 25.

Next, step S4 will be described.

Fig. 5B is an explanatory diagram corresponding to step S4 of Fig. 5A. Fig. 6A is a cross-sectional view taken along line VIA-VIA of Fig. 5B.

In step S4, as shown in Figs. 5B and 6A, the ribs 27 are fixed to the outer side portions 23b of the respective blocking plates 23 by welding. Further, in step S4, the ribs 27 are fixed to the upper surface 15 of the outer roof 7b by welding.

In this manner, since the rib 27 is fixed to the outer side portion 23b of the blocking plate 23, and the rib 27 is fixed to the upper surface 15 of the outer roof 7b, the blocking plate 23 can be reinforced. That is, each of the shutters 23 is stably supported on the outer roof 7b.

In the present embodiment, each of the ribs 27 has a plate shape. Pieces. Further, in the present embodiment, each of the plate-shaped ribs 27 is fixed to the side surface so as to be orthogonal to the side surface of the blocking plate 23. Therefore, each of the ribs 27 is in a state of being extended in a direction perpendicular to the slit 19 into which the shutter 23 to which the rib 27 is fixed is inserted.

In this example, one or a plurality of ribs 27 are fixed by welding to each of the shutters 23 of the slit 19 inserted into the first side L1 and the fourth side L4 (see FIG. 3A) of the target region R0. Both sides. However, one or a plurality of ribs 27 may be fixed to both side faces of the respective blocking plates 23 of the slits 19 inserted into the second side L2 and the third side L3 (see FIG. 3A) of the target region R0.

As an example, in step S4, the ribs 27 may be fixed to the respective column members 25 by welding. In a state where the lower end of each of the column members 25 is in contact with the upper surface 17 of the inner roof 5b, each of the column members 25 has an outer portion 25a located above the upper surface 15 of the outer roof 7b (see FIG. 6A). By way of example, in step S4, the ribs 27 are fixed to the outer side portions 25a of the respective column members 25 by welding, and the ribs 27 are fixed to the upper surface 15 of the outer roof 7b by welding. The shape of the rib 27 fixed to the column member 25 may be the same shape as the rib 27 fixed to the outer side portion 23b of the blocking plate 23.

Next, the description will be given with respect to step S5.

Fig. 7A is an explanatory diagram corresponding to step S5 of Fig. 5B.

In step S5, as shown in Fig. 7A corresponding to Fig. 5B, the upper surface 15 of the outer roof 7b is disposed upward from the upper surface 15 A waterproof board 29 is erected. The waterproof sheet 29 is fixed to the upper surface 15 of the outer roof 7b by, for example, welding. As shown in FIG. 7A, the waterproof sheet 29 is disposed closer to the center side (upper side) of the roof of the storage tank 10 than the first side L1 (see FIG. 3A) of the target region R0.

By the waterproof sheet 29, rainwater is prevented from flowing from the center side of the roof of the storage tank 10 to the upper surface 15 of the outer roof 7b, and penetrates into the portion of the slit 19 and the shutter 23. In other words, when it takes a few days or more to complete the opening method of the roof of the tank of the present embodiment, rainwater can be prevented from infiltrating into the target region R0 by the waterproof sheet 29 even if it is rained. Further, in this case, in the case of rain, in addition to the waterproof sheet 29, the vinyl sheet can be disposed so as to cover the entire object region R0.

Next, step S6 will be described.

In step S6, the heat insulating material filling hole 31 located in the target region R0 is taken out from the working area 9a partitioned by the blocking plate 23 in the heat insulating space 9.

The operation of taking out the granular heat insulating material from the work area 9a can be performed by a suitable suction device. In order to return to the work area 9a afterwards, the sucked granular heat insulating material is temporarily stored in an appropriate container. The particulate insulation material that has been pumped can also be replaced with a new granular heat insulation material.

As described above, steps S1 to S4 are performed before step S6. However, step S5 can also be performed after step S6.

Next, step S7 will be described.

Fig. 7B is an explanatory diagram corresponding to step S7 of Fig. 7A. Fig. 6B is a cross-sectional view taken along line VIB-VIB of Fig. 7B.

In step S7, in the object region R0 of the outer roof 7b, the outside opening 7c is formed by a person using a suitable tool as shown in Fig. 7B. The outer side opening 7c penetrates the outer side roof 7b in the thickness direction. Further, at this point of time, since the granular heat insulating material is taken out from the work area 9a in step S6, the granular heat insulating material is not detached from the work area 9a through the outer opening 7c in step S7.

Next, the description will be given with respect to step S8.

In step S8, the person enters the work area 9a through the outer opening 7c (see FIG. 6B), and various operations are performed in the work area 9a. In this work, there are, for example, the following operations (1) to (5).

(1) Using a suitable sealing material (for example, glass wool or caulking material), plugging the blocking plates 23 partially repeated in the width direction of the slit 19 (for example, the blocking plate 23 with other notches and other shielding plates) 23) The gap.

(2) A gap between the adjacent pairs of the shutters 23 is blocked by a sealing material (for example, a caulking material).

(3) The lower end of each of the shutters 23 and the lower end of each of the column members 25 are fixed to the upper surface 17 of the inner roof 5b by welding (for example, locally).

(4) The lower end of each of the shutters 23 and the gap between the lower end of each of the column members 25 and the upper surface 17 of the inner roof 5b are closed by a sealing member (for example, a caulking material).

(5) When there is a gap between the work area 9a and the other heat insulating space 9, the gap is closed by a sealing material (for example, a caulking material).

By the above operation, it is possible to more reliably prevent the particulate heat insulating material from entering the work area 9a from other areas of the heat insulating space 9. As a result, the person can stably perform the subsequent steps S9, S10 in the work area 9a. industry.

Next, the description will be made with respect to step S9.

Fig. 8A is an explanatory diagram corresponding to step S9 of Fig. 6B.

In step S9, as shown in Fig. 8A, in the work area 9a, the inner side opening 5c that communicates with the storage space 3 of the storage tank 10 is formed on the inner side roof 5b. In the present embodiment, in step S9, the person enters the work area 9a through the outer opening 7c, and the inner opening 5c that communicates with the storage space 3 of the storage tank 10 is formed inside the work area 9a by an appropriate tool. Roof 5b.

Next, step 10 will be described.

Fig. 8B is an explanatory diagram corresponding to step S10 of Fig. 8A.

In step S10, the person arranges the inspection machine 33 in the storage space 3 through the inner opening 5c in the work area 9a as shown in Fig. 8B. This inspection machine 33 is fixed to, for example, the inner roof 5b. In the example of Fig. 8B, the inspection machine 33 has a fixing portion 33a fixed to the inner roof 5b, an extension portion 33b extending from the fixing portion 33a into the storage space 3, and a sensor located at the front end of the extension portion 33b. Part 33c. The sensor unit 33c detects, for example, the pressure or temperature in the storage space 3, the height of the liquid surface of the liquefied gas in the storage space 3, or the density of the liquefied gas.

Then, the outer opening 7c is plugged with a suitable plate member. Next, each of the shutters 23 and the column members 25 are removed from the outer roof 7b. Then, the slit 19 is stuffed by an appropriate means.

Then, the person comes out of the work area 9a through the outside opening 7c. Then, in the state where the inspection machine 33 is placed as described above, the particulate heat insulating material temporarily stored is returned to the work area 9a through the heat insulating material filling hole 31. Alternatively, the replaced new granular heat insulating material is filled in the work area 9a through the heat insulating material filling hole 31.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit and scope of the invention.

For example, in the above description, although the heat insulating material filling hole 31 is located in the target region R0, in the case where this is not the case, the following may be employed. A through hole for taking out the heat insulating material for allowing the outer roof 7b to penetrate in the thickness direction is formed in the target region R0. The particulate heat insulating material is taken out from the work area 9a through the heat insulating material take-out through hole. At this time, after the installation of the inspection machine 33, the through-holes for taking out the heat insulating material are passed through, and the temporarily stored particulate heat insulating material is returned to the work area 9a (or the replaced new granular heat insulating material) Filled in the work area 9a). In this case, the other points are the same as described above.

S1 to S10‧‧‧ steps

Claims (6)

A method for opening a roof of a storage tank, wherein the roof of the storage tank for storing the liquefied gas is opened, wherein the storage tank has a storage space for storing the liquefied gas; and the roof system has: covering the upper part of the storage space An inner side roof; a roof side outer roof covering the outer side roof; and a granular heat insulating material filled in the heat insulating space between the inner side roof and the outer side roof; and the outer surface of the outer roof is mounted from the outer side a central portion of the roof extending radially into a plurality of bone members; the method for opening the roof of the tank includes: (A) extending in a manner surrounding an object area of the outer surface of the outer roof, and avoiding the outer side Forming a plurality of slits divided by the portion in a thickness direction of the roof and a portion overlapping the bone member, wherein the slits penetrate the outer roof in the thickness direction; (B) inserting the plurality of shutters into the respective blocks a plurality of the aforementioned slits, and a working area surrounded by a plurality of the aforementioned blocking plates is formed in the heat insulating space; (C) a transmissive position The heat insulating material filling hole provided in the target region or the heat insulating material taking-out through hole formed in the target region, and the granular heat insulating material is taken out from the working region; (D) in the outer roof In the aforementioned object area, forming the front The outer roof penetrates the outer side opening in the thickness direction. (E) In the work area, an inner opening of the storage space that communicates with the storage tank is formed on the inner roof. The opening method of the roof of the tank according to the above aspect of the invention, wherein each of the blocking plates inserted into the slit in the above (B) has an outer side portion extending from the slit toward the upper side, in the foregoing ( B) After and before (C), the rib is fixed to the aforementioned outer portion of the shutter, and the rib is fixed to the aforementioned upper surface of the outer roof. The method for opening a roof of a tank according to the first or second aspect of the invention, wherein in the above (B), the cover is disposed on both sides of the bone member so as to sandwich the bone member. a blocking plate of one of the broken plates, the region having the same height as the bone member in a state in which the lower end is in contact with the upper surface of the inner roof has a notch portion recessed in the width direction of the bone member, In (B), a plurality of the shutters are inserted into the plurality of slits, and the lower ends of the shutters are brought into contact with the upper surface of the inner roof, and the slits are provided. The breaking plate moves toward the width direction of the bone member, and the bone member is positioned in the notch portion, thereby closing the gap between the thickness direction of the outer roof and the bone member in the heat insulating space by the blocking plate. region. The method for opening a roof of a tank according to claim 3, wherein in the above (B), the aforementioned covering having the notch portion is provided The breaking plate is moved in the width direction of the aforementioned bone member, and the other blocking plate is inserted so that the amount of movement becomes no longer in the longitudinal direction of the slit of the blocking plate. The method for opening a roof of a tank according to the first or second aspect of the invention, wherein before the foregoing (C), in the outer roof, a position adjacent to the slit is formed for the column. a through hole into which the member is inserted, in which the column member is inserted into the through hole, and the lower end of the column member is in contact with the upper surface of the inner roof, the column member is fixed to the outer roof, and the slit is inserted into the slit The aforementioned blocking plate is fixed to the column member. The method for opening a roof of a tank according to the first or second aspect of the invention, wherein the upper surface of the outer roof provided with the object area is inclined with respect to a horizontal plane, and the object area has a square shape a ridge having a first side extending in a horizontal direction; a second side and a third side extending from the both ends of the first side toward the lower side of the outer roof upper surface; and connecting the second side And the fourth side extending in the horizontal direction in the lower end of the third side; in the above (A), the slit is formed in each of the first, second, third, and fourth sides.