JP2016098511A - Construction method for cylindrical tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction method for a cylindrical tank, in which an inner tank side plate can be carried in a tank peripheral direction in a compact configuration without giving influences to other work.SOLUTION: The construction method for the cylindrical tank in a double shell structure, in which an inner tank is assembled inside an outer tank by lifting an inner tank side plate 9 up using a jack-up device and mounting the next inner tank side plate 9 to the lower side of the lifted-up inner tank side plate 9 in an alternately repetitive manner, includes a step of providing a roller unit 100 along the tank peripheral direction for supporting the inner tank side plate 9, a step of fixing an endless winch 120 to the inner tank side plate 9, a step of providing a rope 121 which the endless winch 120 hauls in along the tank peripheral direction, and a step of carrying the inner tank side plate 9 supported by the roller unit 100 in the tank peripheral direction while making the endless winch 120 haul in the rope 121.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a method for constructing a cylindrical tank.

  A double-shell cylindrical tank having an inner tank and an outer tank is used for storing low-temperature liquids such as LNG (liquefied natural gas) and LPG (liquefied petroleum gas). Patent Document 1 discloses a method for constructing a cylindrical tank having a metal inner tank and a concrete outer tank. In this construction method, a method of constructing the inner tank and the outer tank in parallel is adopted in order to shorten the construction period of the cylindrical tank.

  Specifically, the jack up device is supported on the side wall of the outer tank while the side wall of the outer tank is sequentially assembled from the bottom to the top on the bottom of the outer tank of the cylindrical tank. The inner tank side plate is raised from the uppermost to the lowermost one by alternately repeating the raising of the inner tank side plate by the jack-up device and the welding of the next inner tank side plate to the lower side of the raised inner tank side plate. By installing in order, the inner tank and the outer tank are constructed in parallel.

JP 2012-149416 A

  By the way, in the above prior art, the inner tank side plate to be attached next is taken into the space below the inner tank side plate raised by the jack-up device from the construction port, and the taken inner tank side plate is moved to the predetermined position of the tank. The next inner tank side plate is welded to the lower side of the raised inner tank side plate. As a means for conveying the inner tank side plate, for example, a means for installing a monorail in the circumferential direction of the tank and conveying the inner tank side plate to the monorail can be considered.

  However, a transport device such as a monorail has to lay rails along the inside of the outer tub. Inside the outer tub, welding of the inner tub side plate, cold insulation work, and the like are performed, and the laid rail may interfere with the work. In particular, in the vertical welding of the inner tank side plate, it is necessary to perform welding to the lower end of the inner tank side plate, and the operator may perform a welding operation while diving under a laid rail, for example.

  The present invention has been made in view of the above problems, and is a method for constructing a cylindrical tank that can transport the inner tank side plate in the circumferential direction of the tank with a compact configuration without affecting other operations. For the purpose of provision.

  In order to solve the above problems, the present invention, on the inside of the outer tub, the rise of the inner tub side plate by the jack-up device, the attachment of the next inner tub side plate to the lower side of the raised inner tub side plate, Is a method for constructing a cylindrical shell having a double shell structure in which the inner tank is assembled by alternately repeating the steps, and a step of providing a roller unit for supporting the inner tank side plate along the circumferential direction of the tank; A step of fixing the mold winch, a step of providing a rope for the endless winch to be handed along the circumferential direction of the tank, and the inner tank side plate supported by the roller unit by handing the rope to the endless winch. The method of having a process of conveying in the tank circumferential direction is adopted.

  Further, in the present invention, the endless winch includes a leg portion with a wheel that can be expanded and contracted, and while the inner tank side plate is conveyed in the circumferential direction of the tank, the leg portion with the wheel is contracted, and the endless winch is The method of having a step of setting the non-grounding state is adopted.

  Further, in the present invention, after conveying the inner tank side plate, extending the leg portion with the wheel and bringing the endless winch into a grounded state, and releasing the fixing of the endless winch in the grounded state, And a step of separating from the inner tank side plate after conveyance.

In the present invention, the inner tank side plate is supported by the roller unit, the endless winch is fixed to the inner tank side plate, and the rope provided along the circumferential direction of the tank is rolled to convey the inner tank side plate in the circumferential direction of the tank. . By supporting the inner tank side plate on the roller unit, the frictional force at the time of conveying the inner tank side plate can be reduced, so that a compact endless winch can be employed for pulling the inner tank side plate. The endless winch can be moved anywhere by handing the rope, and the rope is thinner than the rail and is easy to install, and has little effect on other operations.
Therefore, in this invention, an inner tank side board can be conveyed in a tank circumferential direction with a compact structure, without affecting other operations.

It is explanatory drawing which shows the 1st process of the construction method in embodiment of this invention. It is explanatory drawing which shows the 2nd process of the construction method in embodiment of this invention. It is explanatory drawing which shows the 3rd process of the construction method in embodiment of this invention. It is explanatory drawing which shows the 4th process of the construction method in embodiment of this invention. It is explanatory drawing which shows the 5th process of the construction method in embodiment of this invention. It is a front view of the endless type winch in the embodiment of the present invention. It is a figure which shows the mode of conveyance of the inner tank side board by the endless type winch in embodiment of this invention. It is a top view of the endless type winch in the embodiment of the present invention. It is a side view of the endless type winch in the embodiment of the present invention.

  Hereinafter, the construction method of the cylindrical tank of the present invention will be described with reference to the drawings. In the following description, a ground type PC (prestressed concrete) double-shell storage tank for storing LNG is exemplified as the cylindrical tank.

  As shown in FIG. 1, in this method, first, construction of a substantially disk-shaped foundation plate 1 (the bottom of the outer tub) is performed. A base portion 3 for assembling the PC wall 2 (outer tank) is provided on the outer peripheral edge of the base plate 1 in a protruding manner. Moreover, the inner tank anchor strap 4 is installed along the inner side of the foundation part 3. Further, the PC wall 2 is placed on the foundation 3. When placing the PC wall 2, a scaffold 5 is provided and a formwork (not shown) is installed.

  Next, the bottom liner 6 is laid on the foundation plate 1. In addition, the roof mount 7 is assembled at the center of the base plate 1. Moreover, the construction port 8 for taking in the inner tank side plate 9 one by one in the base end part of the PC wall 2 is formed. A plurality of gate-type mounts 10 for assembling the inner tank side plate are installed along the inside of the base end of the PC wall 2. The gate-type gantry 10 is installed so that a cylindrical inner tank formed by combining a plurality of inner tank side plates 9 straddles the annular area X, which is an area to be finally lowered on the base plate 1.

  Next, in this method, next, the inner tank side plate 9 is mounted on the gate-type gantry 10, the adjacent inner tank side plates 9 are welded to each other, and are joined together in the circumferential direction so as to be cylindrical as a whole. Further, the knuckle plate 11 is assembled to the upper end portion of the inner tank side plate 9. Further, the structural member 12 of the annular portion 13 (see FIG. 2) such as a pearlite concrete block or a structural lightweight concrete block is temporarily placed in the annular region X under the portal frame 10. Further, the inner tank roof 14 is assembled on the roof mount 7. Further, the inner tank side plate 9 is assembled to the outer peripheral edge portion of the inner tank roof 14 via the knuckle plate 11.

  Under the gate-type gantry 10, the cold insulation work for the annular portion 13 is performed. The cold insulation work of the annular portion 13 is performed by assembling a pearlite concrete block and a structural lightweight concrete block on the bottom portion of the thermal resistance reducing material, and attaching an annular plate thereon. The annular portion 13 finally supports the assembled inner tank side plate 9, the annular plate is formed thick, and the cold insulation structure is also formed of a hard material such as a concrete block.

  When the cold insulation work of the annular part 13 is completed, the leg part arranged inside the tank from the annular part 13 is replaced on the annular part 13 (see FIG. 2). By such replacement, there is no interference on the inside of the tank with respect to the annular portion 13, so that the cold insulation work at the center portion on the base plate 1 can be performed. In the cold insulation work in the central part, as shown in FIG. 3, the foam glass 40 is placed on the bottom cold resistance reducing material 39. Then, a pearlite concrete block (not shown) and an inner tank bottom plate (not shown) are laid on top of each other in this order.

  Returning to FIG. 1, in this method, a plurality of jackup devices 18 are installed on the PC wall 2 in the circumferential direction of the tank in parallel with the cold insulation work. First, between the inner and outer tubs 15 (between the PC wall 2 and the inner tub side plate 9) above the base plate 1, and on the PC wall 2 above the knuckle plate 11, the suspending side jack mount 16 (hanging) Multiple points) are installed in the tank circumferential direction. The suspension side jack mount 16 is provided so as to protrude substantially horizontally from the PC wall 2 having a predetermined height toward the inside of the tank. The suspension-side jack mount 16 is fastened and fixed to, for example, an anchor plate embedded in the PC wall 2 in a strong and detachable manner.

  Further, a plurality of knuckle reinforcement members 17 corresponding to the plurality of jackup devices 18 are installed on the knuckle plate 11. The knuckle reinforcement 17 projects from the knuckle plate 11 toward the inner / outer tank 15. Further, the knuckle reinforcing member 17 serves as a suspended base. The jack-up device 18 is a center hole jack, and attaches the lower end portion of the jack-up rod 19 to the knuckle reinforcement member 17.

  When the jackup device 18 is installed in this manner, as shown in FIG. 2, the roof mount 7 is removed, and the knuckle plate 11 is lifted by the jackup device 18 to raise the inner tank side plate 9. When the jack-up device 18 is raised by one stroke of the jack-up rod 19 (corresponding to the vertical width of the inner tank side plate 9 alone in this embodiment), the jack is raised to the space formed at the lower part of the inner tank side plate 9. The next inner tank side plate 9 is carried in.

  The next inner tank side plate 9 is transported to a predetermined welding position, welds a plurality of inner tank side plates 9 arranged in a ring shape on the gate-type gantry 10, and welds the inner tank side plates 9 arranged vertically. Thus, these inner tank side plates 9 are formed into an integral cylindrical shape. In this way, the raising of the inner tank side plate 9 by the jack-up device 18 and the attachment of the next inner tank side plate 9 to the lower side of the raised inner tank side plate 9 are repeated alternately.

  Next, as shown in FIG. 3, the outer tank roof 22 is assembled on the inner tank roof 14. The outer tank roof 22 is connected to the inner tank roof 14 by a connecting material (not shown), and is assembled integrally with the inner tank roof 14. Moreover, if the PC wall 2 is assembled, the jackup apparatus 18 is installed in the top part, and a suspending point is changed. On the gate-type gantry 10, the raising of the inner tank side plate 9 by the jack-up device 18 and the attachment of the next inner tank side plate 9 to the lower side of the raised inner tank side plate 9 are alternately repeated. The side plates 9 are attached in order from the uppermost one to the lowermost one.

Next, as shown in FIG. 4, when the installation of the inner tank side plate 9 to the lowermost stage is completed, the portal frame 10 is removed, and the lower end of the lowermost stage of the inner tank side plate 9 is lowered onto the annular portion 13, Attached to the inner tank anchor strap 4 installed in the base plate 1. Thereby, the inner tank 30 is completed.
Moreover, the outer tub roof 22 jacked up together with the inner tub roof 14 is disconnected from the inner tub roof 14 by a connecting material (not shown) and installed on the upper end portion of the PC wall 2 assembled to the top. Further, the side liner 2 a is attached to the inner wall surface of the PC wall 2. Further, an elevating staircase 23 is provided outside the PC wall 2. A roof staircase 24 is provided on the outer tank roof 22. Moreover, the pump barrel 25 is carried in.

Thereafter, as shown in FIG. 5, the knuckle reinforcement member 17 is cut off and the jackup device 18 is removed. After that, tension work on the PC wall 2 is performed. Then, after closing the construction port 8 and installing the pump barrel 25, water pressure is applied and a pressure and airtight test is performed.
Finally, a cold insulation material 44 is arranged between the inner and outer tanks 15 and a cold insulation work is performed by arranging the cold insulation material 44 on the back side of the inner tank roof 14. 50 is built.

  Subsequently, the transfer operation of the inner tank side plate 9 in the circumferential direction of the tank in the construction method of the cylindrical tank 50 described above will be described with reference to FIGS.

  In this method, first, as shown in FIG. 6, a roller unit 100 that supports the inner tank side plate 9 is provided along the circumferential direction of the tank. The roller unit 100 includes a support roller 101 that supports the lower end portion of the inner tank side plate 9 on the portal frame 10. The support roller 101 has a groove 101 a on the circumferential surface corresponding to the groove shape formed in the lower end portion of the inner tank side plate 9. The groove 101 a is a V-shaped groove having the same angle as the groove angle of the inner tank side plate 9. For this reason, even if the inner tank side plate 9 is rolled on the roller unit 100, the groove shape is not crushed.

  The rotating shaft 102 of the support roller 101 is rotatably supported by a bearing 103. The rotating shaft 102 extends in the tank radial direction orthogonal to the circumferential direction of the tank (the depth direction in FIG. 6), and both ends thereof are supported by the bearing 103 so as to be slidable with a predetermined width. The bearing 103 smoothly conveys the inner tank side plate 9 by supporting the rotating shaft 102 slidably in the tank radial direction. That is, the bearing 103 prevents the biting into the groove 101a of the inner tank side plate 9 by, for example, giving the support roller 101 a certain degree of freedom. The bearing 103 is fixed on the beam member 104. The beam member 104 is installed between the gate-type mounts 10 adjacent in the tank circumferential direction.

  A guide portion 110 is installed on the inner tank side plate 9 supported by the roller unit 100. The guide part 110 is for preventing the inner tank side plate 9 that is welded to the lower side of the inner tank side plate 9 raised by jacking up from falling. The guide part 110 is formed by a pair of guide members (a first guide member 111 and a second guide member 112). The first guide member 111 and the second guide member 112 are attached to the plate surface of the inner tank side plate 9 via the hose shoe 113. The horseshoe 113 is a substantially U-shaped portal steel material. The hose shoe 113 is welded to the inner tank side plate 9, and the first guide member 111 and the second guide member 112 are fixed to the inner tank side plate 9.

  The first guide member 111 includes a guide roller 114 that rolls on the inward plate surface of the inner tank side plate 9. The guide roller 114 has a rotation shaft 115 that extends in the vertical direction. The rotating shaft 115 is rotatably supported by the first guide member 111. The first guide member 111 is installed below the key nut 53 of the inner tank side plate 9. The key nut 53 is previously welded for skin alignment when welding the adjacent inner tank side plates 9. A jig for positioning and fixing adjacent inner tank side plates 9 is attached to the key nut 53 during welding.

  On the other hand, the second guide member 112 includes a guide roller 116 that rolls on the outward plate surface of the inner tank side plate 9. The guide roller 116 has a rotation shaft 117 that extends in the vertical direction. The rotating shaft 117 is rotatably supported by the second guide member 112. A key nut 53 is not provided on the outward plate surface of the inner tank side plate 9. Therefore, the second guide member 112 is installed so as to extend upward from the first guide member 111. That is, the guide roller 116 of the second guide member 112 can roll at the same height as the key nut 53.

  In this method, the endless winch 120 is fixed to the inner tank side plate 9. The endless winch 120 is a winder that winds out the rope 121 by the length of the rope 121 when the rope 121 is wound, and can wind up indefinitely as long as the length of the rope 121 allows. The endless winch 120 includes a main body portion 122 that winds the rope 121, a fixing portion 123 that is fixed to the inner tank side plate 9, a leg portion 124 (a leg portion with wheels) provided at a lower portion of the main body portion 122, and a main body And a gripping part 125 for pushing and pulling the part 122.

  As shown in FIG. 8, the main body 122 includes a pair of sheaves 131, a winding drum 132 that winds the rope 121, a pair of adjustment sheave 133 that adjusts the pressing force of the rope 121 against the winding drum 132, and the winding drum 132. And a motor 134 for rotating the motor. When the winding drum 132 is rotated by the motor 134, the rope 121 is wound up through the sheave 131 on the towing side, and the rope 121 is fed out through the sheave 131 on the feeding side. The pair of adjustment sheaves 133 are provided so as to be freely displaceable, and the displacement enables the gripping of the winding drum 132 to the rope 121 to be ensured.

  The fixing portion 123 includes a fixing plate 141 protruding from the side surface of the main body portion 122, a fixing hole 142 provided in the fixing plate 141, a cushion material 143 provided at the tip of the fixing plate 141, and the back side of the fixing plate 141. A pantograph jack 144 provided on the pantograph jack, and a rubber plate 145 provided on the pantograph jack 144. As shown in FIG. 6, the fixing plate 141 is fixed to the inward plate surface of the inner tank side plate 9. The fixing plate 141 is firmly fixed to the inner tank side plate 9 by, for example, welding a fixing piece (not shown) to the inner tank side plate 9 and passing a fixing tool such as a bolt through the fixing hole 142. Further, the pantograph jack 144 is extended, pressed against the inner tank side plate 9, and fixed through a fixing tool (not shown) such as a fixing piece and a bolt. As a result, the main body 122 is supported by the inner tank side plate 9.

  The leg part 124 has a wheel 151 provided at the grounding part (lower end part), and a pantograph jack 152 that includes the wheel 151 and can be expanded and contracted. As shown in FIG. 9, the leg portion 124 includes a wheel 151 and a pantograph jack 152 at the front and rear, and can be grounded at four points. As shown in FIG. 6, the leg 124 is in a grounded state in which it can run on the plate material 54 installed between the gate-type gantry 10 adjacent in the tank circumferential direction, and in a non-grounded state in which it is separated from the plate material 54. Can do. The grip portion 125 is provided in the main body portion 122 to push and move the endless winch 120 in a grounded state.

  Moreover, in this method, the rope 121 which the endless type winch 120 handles is provided along the tank circumferential direction as shown in FIG. Both ends of the rope 121 are tied and fixed to appropriate locations in the tank. The rope 121 is arranged inside the transport path L of the inner tank side plate 9 and outside the column 52 of the temporary scaffold for welding the inner tank side plate 9. A pole 51 is erected between the columns 52 of the temporary scaffold so that the rope 121 does not hit the columns 52 of the temporary scaffold. The pole 51 is disposed on the outer side in the tank radial direction than the column 52 of the temporary scaffold, and is disposed on the outer side of the transport path of the endless winch 120.

Thus, in this method, the inner tank side plate 9 is supported by the roller unit 100 shown in FIG. 6, the endless winch 120 is fixed to the inner tank side plate 9, and the rope 121 provided along the circumferential direction of the tank is handed over. The inner tank side plate 9 is conveyed in the tank circumferential direction. By supporting the inner tank side plate 9 on the roller unit 100, the frictional force when the inner tank side plate 9 is conveyed can be reduced, so that a compact endless winch 120 can be employed for pulling the inner tank side plate 9. The endless winch 120 can be moved anywhere by handling the rope 121, and the rope 121 is thinner than the rail, is easy to install, and hardly affects other operations.
Therefore, according to the present method, the inner tank side plate 9 can be transported in the circumferential direction of the tank with a compact configuration without affecting other operations.

  Further, the endless winch 120 includes a leg portion 124 that can be expanded and contracted, and while the inner tank side plate 9 is conveyed in the circumferential direction of the tank, the leg portion 124 is contracted so that the endless winch 120 is not grounded. According to this method, since the endless winch 120 is in a floating state, interference with a structure on the ground can be avoided. Further, since the endless winch 120 is in a floating state, the frictional force between the leg portion 124 and the plate material 54 is eliminated, and the conveyance resistance of the inner tank side plate 9 can be reduced.

  Further, in this method, after the inner tank side plate 9 is transported, the legs 124 are extended, the endless winch 120 is brought into a grounded state, the endless winch 120 in a grounded state is released, and the inner tank side plate after the transporting is released. Separated from 9. By extending the leg portion 124, the endless winch 120 can be prevented from falling even if the endless winch 120 is released from being fixed. Further, when the endless winch 120 is released from the fixed state, it can be easily moved by holding the grip 125 and pushing it. Then, the endless winch 120 is returned to the initial position, for example, around the inner tank side plate 9 taken from the construction port 8 in the circumferential direction of the tank, and fixed to the next inner tank side plate 9. The Rukoto. When the endless winch 120 is returned to the initial position, the winding drum 132 may be made free or removed from the rope 121.

  Thus, according to the above-described embodiment, inside the PC wall 2, the inner tank side plate 9 is lifted by the jack-up device 18, and the next inner tank side plate 9 to the lower side of the raised inner tank side plate 9. And a step of providing a roller unit 100 supporting the inner tank side plate 9 along the circumferential direction of the tank. A step of fixing the endless winch 120 to the inner tank side plate 9, a step of providing a rope 121 that the endless winch 120 handles along the circumferential direction of the tank, a hand holding the rope 121 to the endless winch 120, and a roller unit. Influencing other operations by adopting a technique of having a step of conveying the inner tank side plate 9 supported by 100 in the circumferential direction of the tank Ku, may carry inner tank side plate 9 to the tank circumferential direction in a compact configuration.

  The preferred embodiment of the present embodiment has been described above with reference to the drawings, but the present embodiment is not limited to the above embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the spirit of the present embodiment.

2 PC wall (outer tank)
9 Inner tank side plate 18 Jack up device 30 Inner tank 50 Cylindrical tank 100 Roller unit 120 Endless winch 121 Rope 124 Leg 151 Wheel 152 Pantograph jack

Claims (3)

Inside the outer tub, a double shell structure in which the inner tub is assembled by alternately repeating the rise of the inner tub side plate by the jack-up device and the attachment of the next inner tub side plate to the lower side of the raised inner tub side plate. A cylindrical tank construction method,
Providing a roller unit supporting the inner tank side plate along the circumferential direction of the tank;
Fixing the endless winch to the inner tank side plate;
A step of providing a rope that the endless winch handles in the circumferential direction of the tank;
A method of constructing a cylindrical tank, comprising the step of feeding the rope to the endless winch and transporting the inner tank side plate supported by the roller unit in a circumferential direction of the tank. The endless winch includes a leg portion with a wheel that can be expanded and contracted,
2. The cylindrical tank according to claim 1, further comprising a step of shrinking the wheel leg portion and bringing the endless winch into a non-grounding state while the inner tank side plate is conveyed in the circumferential direction of the tank. Construction method. After transporting the inner tank side plate, extending the wheeled leg and bringing the endless winch into a grounded state;
The method for constructing a cylindrical tank according to claim 2, further comprising: releasing the fixing of the endless winch in the grounded state and separating the endless winch from the inner tank side plate after transport.

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