JP2005178825A - Closing method and closing structure of external tank roof construction port - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To safely, easily and quickly perform the removing work of a risen section of an external tank roof construction port, and the closing work of the external tank roof construction. <P>SOLUTION: This closing structure is employed for the external tank roof construction port for which a construction port 6 having the risen section 9 is provided on an external tank roof 4. The closing structure for the external tank roof construction port is equipped with a drop lid supporting member 17 which is fixed in a manner to roughly go along the construction port 6 on the lower surface of the external tank roof 4, a drop lid 20 which can airtightly close the construction port 6 by being inserted from the construction port 6 and fixed to the drop lid supporting member 17 through a seal material, and a closing plate which closes the construction port 6 clear of the risen section 9, from outside of the external tank roof 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a closing method and a closing structure for an outer tub roofing work opening, which enables the removal of the rising portion of the outer tub roofing work opening and the closing operation of the outer tub roofing work opening to be performed safely, easily and quickly. .

  Some low temperature liquefied gas tanks are called double shell tanks having an outer tank 1 and an inner tank 2 as shown in FIG. 8, and the outer tank 1 is made of concrete (or PC concrete). There is. In FIG. 8, 3 is a concrete outer tank side wall, 4 is an outer tank roof, and 5 is an inner tank roof.

  In the above-mentioned double shell tank, after the outer tub 1 is constructed, the outer tub roof 4 and the inner tub roof 5 assembled inside the outer tub 1 are raised by an air pressurization method called an air lasing method. Is fixed to the upper end of the outer tank side wall 3. And the side wall member 7 grade | etc., Is suspended through the construction port 6 formed in the outer tank roof 4, and the inner tank side wall 8 of the inner tank 2 is constructed | assembled. Further, a cold insulating material is inserted between the outer tub 1 and the inner tub 2 through the construction port 6 and installed.

  The construction port 6 provided in the outer tub roof 4 has a configuration shown in FIGS. The construction port 6 has a rising portion 9 rising at a required height along the peripheral edge of the construction port 6, and a closing lid 11 can be attached to and detached from the upper end of the rising portion 9 via a flange 10. The construction opening 6 can be opened and closed by the closing lid 11.

  The outer peripheral lower end of the outer tub roof 4 is fixed at a position lower than the upper end of the concrete outer tub side wall 3 as shown in FIG. 9. For this purpose, the inner surface of the outer tub side wall 3 and the lower end of the outer tub roof 4 are fixed. A triangular corner portion 12 is formed between the upper surface and rainwater is accumulated in the corner portion 12 to generate rust, and it is considered that water penetrates into the outer tub 1. .

  In order to cope with this problem, there is a structure in which a rainwater prevention plate is provided in the corner portion 12 to form a triangular space, and an inert gas is supplied to the space to reduce the oxygen concentration inside the space. (For example, refer to Patent Document 1).

  On the other hand, as a method for preventing rainwater from accumulating in the corner portion 12, as shown in FIG. 12, by placing shoulder concrete 13 from the upper end of the outer tub side wall 3 to the upper surface of the outer tub roof 4, It is considered to eliminate the portion 12.

  In this case, as shown in FIG. 8, since the side wall member 7 and the like need to be suspended between the outer tub 1 and the inner tub 2, the construction port 6 is provided at a position close to the outer tub side wall 3. The shoulder concrete 13 is applied to the work opening 6, which requires the work opening 6 to be closed.

  For this purpose, it is necessary to remove the rising portion 9 shown in FIG. 9 by fusing, and then close the construction port 6 by welding the closing plate 14 to the outside of the outer tank roof 4. However, since the work for closing the construction port 6 is close to completion of tank construction, a cold insulating material is already installed between the inner and outer tanks.

For this reason, in order to close the construction opening 6, first, as shown in FIG. 11, the closing lid 11 is removed, members are loaded from the construction opening 6, and the flame is cured between the outer tank roof 4 and the inner tank roof 5. Assemble the scaffold 15. At this time, if the cold insulation material is in the way, a part of the cold insulation material is removed. Next, the sheet | seat 16 is installed on the spark-curing scaffold 15 and the rising part 9 is removed by fusing after that. Garbage such as sparks and chips generated by fusing the rear rising portion 9 is prevented from dropping onto the lower cooling material by the sheet. Thereafter, the sheet 16 and the fire-curing scaffold 15 are removed from the construction entrance 6, and the removed cold insulation material is installed. Then, the closing plate 14 is placed on the upper side of the outer tub roof 4 from which the rising portion 9 is removed as shown in FIG. Weld and close construction port 6. Subsequently, the shoulder concrete 13 is placed from the upper end of the outer tank side wall 3 to the upper surface of the lower end of the outer tank roof 4 so as to eliminate the corner portion 12.
JP 08-338598 A

  However, in the construction port closing method shown in FIGS. 9 to 12, the fire powder curing scaffold 15 for assembling the sparks and chips when the rising portion 9 is melted is prevented from falling down. Although the seat 16 is installed on the upper part, the installation work and the work of removing these after the fusing are very difficult, and there is a problem that takes time and labor. Furthermore, even if the sheet 16 is installed, it is difficult to completely prevent dust such as sparks and chips from falling down.

  The present invention has been made in view of the above circumstances, and the outer tub roofing work opening that allows the removal of the rising portion of the outer tub roofing work opening and the closing work of the outer tub roofing work opening to be performed safely, easily and quickly. The object of the present invention is to provide a closing method and a closing structure.

  The invention according to claim 1 is a method of closing an outer tank roof construction opening provided with a construction opening having a rising portion on the outer tank roof, and is dropped on the lower surface of the outer tank roof so as to substantially follow the construction opening. Install the support member in advance, drop it from the construction port, insert the lid, drop and fix it tightly to the lid support member, close the construction port, then cut off the rising part, and then close the construction port from the outside of the outer tank roof The present invention relates to a method for closing an outer tank roof construction opening, which is closed with a plate.

  According to a second aspect of the present invention, in the method for closing an outer tank roof construction opening according to the first aspect, the drop lid fixed to the lid support member is hermetically fixed with a sealing material. It is concerned.

  The invention according to claim 3 is a closed structure of the outer tank roof construction opening provided with a construction opening having a rising portion on the outer tank roof, and is fixed to the lower surface of the outer tank roof so as to substantially follow the construction opening. The dropped lid support member, a drop lid that can be inserted through the construction opening and fixed to the lid support member through a sealing material, and the construction opening can be hermetically closed, and the construction opening after the rising portion has been cut off are placed on the outer tank roof. The present invention relates to a closing structure for an outer tank roof construction opening, characterized in that it includes a closing plate that is closed from the outside.

  According to a fourth aspect of the present invention, the drop lid is composed of a plurality of divided lid members, and the construction port is hermetically closed by inserting each lid member through the construction port and fixing the lid member side by side on the lid support member. It is made to do. It concerns on the closed structure of the outer tank roof construction opening of Claim 3 characterized by the above-mentioned.

  According to the present invention, when constructing the outer tank roof, it is dropped on the lower surface of the outer tank roof and a lid support member is attached in advance, and when it is necessary to close the construction opening, the dropping lid is inserted from the construction opening. Since it was installed on the drop lid support member and the drop lid and lid support member were sealed with a sealing material, even if the work to remove the rising part by fusing was performed, dust such as sparks and chips at the time of fusing Can be received by the lid, and therefore, it is possible to completely prevent the dust from falling to the lower part and perform a safe operation.

  In addition, since the configuration for preventing dust such as sparks and chips from falling when the rising part is melted and removed can be performed only by installing a dropping lid, a conventional method of installing a spark curing scaffold Compared to the above, the work can be remarkably simplified, and the construction opening can be easily and quickly closed in a short time.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIGS. 1-7 is an example of the form of the closed structure of the outer tank roof construction opening of this invention, Comprising: A basic structure is a structure substantially the same as the structure shown in FIGS. 8-12, The same components as those shown in FIGS. 8 to 12 are denoted by the same reference numerals.

  As shown in FIGS. 1 and 2, a drop lid support member 17 that protrudes downward so as to substantially follow the construction port 6 is fixed to the lower surface of the outer tub roof 4. The construction port 6 is usually oval or circular as shown in FIG. 10, whereas the drop lid support member 17 is fixed to the structural member 18 of the outer tub roof 4, for example, a hexagonal shape It is said. Such a shape is relatively easy to construct. A support portion 19 bent inward is provided at the lower end of the drop lid support member 17. The drop lid support member 17 is installed in advance when the outer tank roof 4 is constructed. Moreover, in the example of FIG. 1, the upper surface of the outer tub roof 4 from the upper end of the outer tub side wall 3 is not formed between the inner surface of the outer tub side wall 3 and the lower end upper surface of the outer tub roof 4. An angled upper surface member 28 extending horizontally toward is provided.

  On the other hand, as shown in FIGS. 3 and 4, a drop lid 20 is provided that can be installed on the support portion 19 of the drop lid support member 17 by being inserted from the construction port 6. As shown in FIGS. 4 and 5, the drop lid 20 is composed of three divided lid members 20a, 20b, and 20c. On the upper surface of the central lid member 20b, the left and right lid members 20a and 20c are arranged. A bracket 21 is fixed by welding 22 for mounting and closing a gap between the central lid member 20b and the left and right lid members 20a and 20c. The support portion 19 that supports the lid members 20a, 20b, and 20c has a bolt 23 that passes through the support portion 19 and protrudes upward, and is fixed to the lower surface of the support portion 19 by welding 22, and the lid The members 20a, 20b, and 20c are formed with holes 24 that fit into the bolts 23. By fitting the holes 24 into the bolts 23 and tightening the nuts 26 through washers 25, the lid members 20a, 20 b and 20 c are fixed to the support portion 19. Further, a sealing material 27 such as putty is applied between the upper surface of the support portion 19 and the end portions of the lid members 20a, 20b, and 20c. Further, a sealing material 27 such as putty is also applied between the end of the bracket 21 of the central lid member 20b placed on the left and right lid members 20a and 20c and the upper surface of the lid members 20a and 20c. ing.

  Further, as shown in FIG. 7, a closing plate 14 similar to FIG. 12 is provided for closing the construction port 6 after welding by removing the rising portion 9 of the construction port 6 by fusing.

  Next, a method for closing the outer tub roof construction opening in the above embodiment will be described.

  When constructing the outer tub roof 4, as shown in FIGS. 1 and 2, a drop lid support member 17 having a support portion 19 at the lower end is attached to the lower surface of the outer tub roof 4 in advance. Further, the bolts 23 shown in FIG. The drop lid support member 17 can be constructed relatively easily by using, for example, a hexagonal shape that is fixed to the structural member 18 of the outer tub roof 4.

  In order to remove the rising portion 9 by fusing in order to close the construction port 6, first, the closing lid 11 is removed from the rising portion 9, and then, as shown in FIGS. 3 and 4, the lid 20 is dropped from the construction port 6. It is inserted and dropped and installed on the support portion 19 of the lid support member 17. At this time, since the drop lid 20 is constituted by the lid members 20a, 20b, and 20c divided into three, the insertion and installation work can be easily performed. 4 and 5, the holes 24 of the inserted lid members 20a and 20c are first fitted on the bolts 23 and placed on the support portion 19, and then tightened by the nut 26 via the washer 25, The members 20 a and 20 c are fixed to the support portion 19. Further, a sealing material 27 such as a putty is applied between the upper surface of the support portion 19 and the ends of the lid members 20a and 20c for sealing. Next, the lid member 20b is installed so that the bracket 21 of the lid member 20b is placed on the left and right lid members 20a and 20c, and the end of the lid member 20b is also the same as the lid members 20a and 20c. Further, it is fixed to the support portion 19 with bolts 23 and sealed with a sealing material 27, and further, a sealing material 27 such as a putty is applied between the end portion of the bracket 21 and the upper surfaces of the lid members 20a and 20c for sealing.

  Subsequently, as shown in FIG. 6, the rising portion 9 is removed by fusing. At this time, the lower part of the construction port 6 is surrounded by the drop lid support member 17 and the drop lid 20 and is sealed by the sealing material 27, so that dust such as sparks and chips at the time of fusing can fall to the lower part. It can be completely prevented and therefore safe work can be carried out.

  Next, the dust inside the drop lid support member 17 and the drop lid 20 is removed, and if necessary, a cold insulation material 29 is loaded inside the drop lid support member 17 and the drop lid 20 as shown in FIG. Thus, the blocking plate 14 is installed on the outer tank roof 4 and fixed to the outer tank roof 4 by welding.

  Since the construction port 6 is closed as described above, the shoulder concrete 13 can be placed from the upper end of the outer tank side wall 3 to the upper surface of the lower end of the outer tank roof 4.

  As described above, when the outer tank roof 4 is constructed, the lid support member 17 is attached to the lower surface of the outer tank roof 4 in advance, and when the construction port 6 needs to be closed, the lid is dropped from the construction port 6. 20 is inserted and installed on the support portion 19 of the drop lid support member 17, and the drop lid 20 and the drop lid support member 17 are sealed with the sealing material 27, so the work of removing the rising portion 9 by fusing is removed. Even if it is carried out, all dusts such as sparks and chips at the time of fusing can be dropped and received by the lid 20, so that it is possible to completely prevent the dust from falling to the lower part and perform a safe operation.

  Furthermore, since the structure for preventing the fall of dust such as sparks and chips when the rising portion 9 is melted and removed can be performed only by installing the dropping lid 20 as described above, the conventional fire powder curing scaffold 15 ( Compared with the method of installing FIG. 11), the work can be remarkably simplified, and the construction entrance can be closed easily and quickly in a short time.

  The present invention is not limited to the above-described embodiment, and various shapes can be adopted for the drop lid support member and the drop lid, and various modifications can be made without departing from the scope of the present invention. Of course.

It is a cut side view which shows an example of embodiment of the closing structure of the outer tank roof construction opening of this invention. It is an II-II direction arrow line view of FIG. It is a cutting | disconnection side view which shows the state which inserted and installed the drop cover in the drop cover support member. It is an IV-IV direction arrow line view of FIG. It is a cutting | disconnection side view which shows the structure which installs a dropping lid in a support part. It is a cutting | disconnection side view which shows the state which melted up the standing part in the state which installed the drop lid. It is a cutting | disconnection side view which shows the state which obstruct | occluded the construction port with the obstruction board. It is a cut side view which shows an example of the low temperature liquefied gas tank of a double shell tank system. It is a cut side view which shows an example of the conventional construction opening. It is a XX direction arrow line view of FIG. It is a cutting side view showing the composition which installed the spark curing scaffold in the lower part of the construction entrance. It is a cutting | disconnection side view which shows the state which obstruct | occluded the construction port with the obstruction board.

Explanation of symbols

4 Outer tank roof 6 Construction entrance 9 Rising part 14 Blocking plate 17 Drop cover support member 19 Support part 20 Drop cover 20a, 20b, 20c Cover member 27 Sealing material

Claims (4)

  A method for closing an outer tank roof work opening provided with a work opening having a rising part on the outer tank roof, and dropping the cover support member in advance on the lower surface of the outer tank roof so as to substantially follow the work opening, The construction opening is closed by inserting and dropping the lid and fixing it to the lid support member in an airtight manner, and then the rising portion is excised, and then the construction opening is closed from the outside of the outer tank roof with a closing plate. How to close the outer tank roof construction entrance.   2. The method for closing an outer tub roof construction opening according to claim 1, wherein a drop lid fixed to the lid support member is hermetically fixed with a sealing material.   It is a closed structure of an outer tank roof construction opening provided with a construction opening having a rising part on the outer tank roof, and a drop lid support member fixed to the lower surface of the outer tank roof substantially along the construction opening, and from the construction opening A drop lid that can be closed airtightly by inserting and fixing it to the lid support member by dropping the seal material, and a closing plate that closes the work opening from the outside of the outer tub roof after the rising portion has been excised. The closed structure of the outer tank roof construction opening, characterized by having.   The drop lid is composed of a plurality of lid members, and each of the lid members is inserted from the construction port, and is placed side by side on the lid support member to fix the construction port in an airtight manner. The closed structure of the outer tank roof construction opening according to claim 3.

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