JP5120693B2 - Method for forming floating roof of storage tank and floating roof of storage tank - Google Patents

Description

  The present invention relates to a method for forming a floating roof of a storage tank and a floating roof of a storage tank.

  Examples of this type of storage tank floating roof include a pan deck type floating roof, a so-called pan type floating roof, a floating roof with a pontoon disclosed in Patent Document 1, a so-called pontoon type floating roof, and the like. In particular, a pan-type floating roof with an economical structure was adopted as the internal floating roof of the floating roof storage tank with a fixed roof.

JP-A-2005-153966

  However, the pan type with a floating roof has an economic structure, there is a risk that the strength will be insufficient during an earthquake. In addition, when the floating roof deck has a hole, or when the storage liquid blows up from between the floating roof and the side plate of the storage tank in the event of abnormal boiling, abnormal pressure, etc., the stored liquid is placed on the floating roof deck. As a result, the floating roof may be inclined or the buoyancy of the floating roof may be reduced. The inventor of the present application examined remodeling the floating roof to a pontoon type in order to eliminate such fears and concerns. However, unlike the case where the floating roof is formed as a pontoon type from the beginning as in Patent Document 1, when the floating roof is remodeled from the pan type to the pontoon type, the weight of the outer peripheral portion where the pontoon is formed becomes the outer periphery of the pan type floating roof. As will be described in detail later with reference to FIG. 2, a new problem has arisen that the entire shape of the floating roof is deformed.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for forming a floating roof of a storage tank and a floating roof of the storage tank, which are prevented from being deformed by remodeling from a pan type to a pontoon type. There is.

In order to solve the above-mentioned problem, the invention of the method for forming a floating roof of a storage tank according to claim 1 according to the present invention is characterized in that a pontoon is formed on an outer peripheral portion on a deck of an existing pan type floating roof body , and A method of forming a floating roof of the storage tank that installs a weight that prevents deformation due to the rise of the center of the deck at the center of the upper surface, or a deck corresponding to a pontoon formed on the outer periphery of the deck if the weight is not installed When a floating body that increases buoyancy and prevents deformation due to sinking of the outer periphery of the deck is installed on the lower surface to form a floating roof of the storage tank, or when the weight is not installed and the floating body is not installed is this to prevent deformation due to sinking of the outer peripheral portion of the deck to increase the buoyancy by increasing the interior volume of space below the liquid surface of the pontoons to move the lower plate of the pontoon from the liquid surface downward The features.

Further, the floating roof of the storage tank according to the invention of claim 2 has a pontoon type floating roof main body in which a pontoon is formed on the outer peripheral portion by modifying an existing pan type floating roof main body, and the buoyancy of the outer peripheral portion on which the pontoon is formed. And at least one of a structure for increasing the buoyancy increasing structure and a structure for installing a weight that suppresses deformation of the center of the upper surface of the deck of the floating roof main body.

The method for forming a floating roof of a storage tank according to the invention of claim 1 is to form a pontoon on the outer peripheral portion on the deck of an existing pan type floating roof body and remodel the pan type floating roof body into a pontoon type floating roof body. Accordingly, since the weight of the outer peripheral portion is increased, the outer peripheral portion sinks, the central portion of the deck (deck center) is Ri Moriaga, for this,浮屋fundamental body is deformed into shaped cross section f For the sinking with respect to the increase in the weight of the outer peripheral part, it is formed in a buoyancy increasing structure, or for the rising of the central part of the deck, a weight is installed in the central part of the deck (the center of the deck). This prevents the sinking of the lower part and the bulge of the center part of the deck. That is, when the buoyancy increasing structure is formed , the buoyancy of the outer peripheral portion is increased, so that the outer peripheral portion (that is, the pontoon) can be prevented from sinking downward. In addition, if a holding structure is formed, the rise at the center of the deck can be suppressed. For this reason, the formation method of the floating roof of the storage tank according to the present invention that forms at least one of the two structures is a formation method of the floating roof of the storage tank that is prevented from being deformed by modification to the pontoon type.
In this way, remodeling the floating roof from the pan type to the pontoon type eliminates the trouble of removing the pan type floating roof to form the pontoon type floating roof, which is economical and easy to carry in materials. And the like. In particular, the present invention is effective in the case of an internal floating roof of a floating roof storage tank with a fixed roof in which the material entrance is limited.

The floating roof of the storage tank according to the invention of claim 2 increases the buoyancy of the pontoon type floating roof main body in which the existing pan type floating roof main body is modified to form a pontoon on the outer peripheral portion and the outer peripheral portion on which the pontoon is formed. At least one of a buoyancy-increasing structure or a structure in which a weight for suppressing deformation of the center of the upper surface of the deck of the floating roof main body is provided. Therefore, the floating roof is prevented from being deformed by remodeling to the pontoon type.

  An embodiment of the present invention will be described with reference to the drawings. In the drawings, the same, corresponding, and generic items will be described with the same reference numerals. The present invention is not limited to the following embodiments. It goes without saying that the embodiments can be modified without departing from the gist of the present invention. It goes without saying that the constituent elements of the embodiment can be omitted without departing from the gist of the present invention.

  In the method of forming a floating roof of a storage tank according to the present embodiment, a pontoon is formed on the outer peripheral portion of a pan type floating roof body already formed in the storage tank, and the pan type floating roof body is modified to a pontoon type floating roof body. In addition, at least one of a buoyancy increasing structure for increasing the buoyancy of the outer peripheral portion where the pontoon is formed or a pressing structure for pressing the center of the deck of the floating roof body is formed. In the present invention, the order of performing the step of remodeling the pontoon type floating roof body and the step of forming at least one of the buoyancy increasing structure or the holding structure may be appropriately determined, and both steps may be performed in parallel. In the present embodiment, the storage tank is a floating roof type storage tank with a fixed roof, and the floating roof is an internal floating roof of the storage tank, but the present invention can be applied to a storage tank without a fixed roof. is there. In addition, when the floating roof is formed into a pontoon type, by changing the floating roof from a pan type to a pontoon type, it is possible to eliminate the trouble of removing the pan type floating roof and forming a pontoon type floating roof. And the material is easy to carry in. In particular, the present invention is effective in the case of an internal floating roof of a floating roof storage tank with a fixed roof in which the material entrance is limited.

  In addition, the floating roof of the storage tank according to the present embodiment is a pontoon type floating roof body in which the pontoon is formed on the outer peripheral portion by modifying the pan type floating roof body, and the buoyancy increase that increases the buoyancy of the outer peripheral portion on which the pontoon is formed. And at least one of a structure and a pressing structure for pressing the center of the deck of the floating roof body.

  An example of this embodiment will be described in detail with reference to FIGS. Note that members, structures, and the like described below are basically formed of a metal such as iron or steel.

  As shown in FIGS. 1 to 3, a floating roof storage tank 10 with a fixed roof according to an example of this embodiment includes a bottom plate 12 formed on a base (not shown), a cylindrical side plate 11 formed on the bottom plate 12, A roof 13 is formed on the upper end of the side plate 11. The floating roof storage tank 10 with a fixed roof stores the storage liquid 20. The floating roof storage tank 10 with a fixed roof has an internal floating roof that floats on the liquid surface 21 of the storage liquid 20. The storage liquid 20 is water, liquid fuel, or the like.

  101 of FIG. 1 shows a pan type internal floating roof main body (pan deck type internal floating roof). As shown in FIG. 1, the pan type internal floating roof body 101 is formed by a disk-shaped deck 103 and an outer peripheral rim plate 105 erected on the outer periphery of the deck 103 on an edge (outer periphery) concentric circle of the deck 103. Is done. The outer peripheral rim plate 105 is formed in an annular shape along the edge of the deck 103. The pan type internal floating roof body 101 has an inner peripheral rim plate (see the inner peripheral rim plate 4 in FIG. 2), or an inner peripheral rim plate (see the inner peripheral rim plate 4 in FIG. 2) and an outer peripheral rim plate. In some cases, a partition plate (bulk head: not shown) that connects and partitions 105 is formed. The inner peripheral rim plate is formed in an annular shape inside the outer peripheral rim plate 105 and at a predetermined interval from the outer peripheral rim plate 105.

  In FIG. 1 to FIG. 3, a sealing material formed between the internal floating roof 1 (or 101) and the side plate 11 for sealing the liquid surface 21 is omitted.

A pontoon 6 is formed on the outer periphery of the pan type internal floating roof body 101 already formed in the floating roof storage tank 10 with a fixed roof (already floated on the storage liquid 20), and the pan type internal floating roof body 101 is pontooned. To modify the type internal floating roof body 1a (that is, to modify the pan type internal floating roof to the pontoon type internal floating roof), for example, as shown in FIG. 2, the outer peripheral rim plate 5 (corresponding to the outer peripheral rim plate 105). .), An annular inner peripheral rim plate 4 is formed concentrically with the outer peripheral rim plate 5 at a predetermined distance from the outer peripheral rim plate 5, and the upper plate 7 is formed as the outer peripheral rim plate 5 and the inner peripheral rim plate. It is formed so as to be bridged over 4 and covered. Further, when the inner peripheral rim plate 4 is formed in advance, it is only necessary to form the upper plate 7 so as to span the outer peripheral rim plate 5 and the inner peripheral rim plate 4. Thus, the pontoon 6 is formed in the outer peripheral part of the pan type internal floating roof main body 101 using at least the outer peripheral rim plate 5 (and the inner peripheral rim plate 4).
The pontoon 6 is formed by an outer peripheral rim plate 5 and an inner peripheral rim plate 4, and an upper plate 7 that connects and covers (bridges) the upper edge of the outer peripheral rim plate 5 and the upper edge of the inner peripheral rim plate 4. A pontoon 6 in an annular space formed by the outer peripheral rim plate 5, the inner peripheral rim plate 4, and the upper plate 7 is a partition plate that connects and partitions the inner peripheral rim plate 4 and the outer peripheral rim plate 5 in the radial direction. (Bulkhead: not shown) is divided into compartments (not shown). As described above, since the pontoon 6 is formed as a compartment, even if a leak occurs in one compartment, the buoyancy is safely maintained by the buoyancy held by the other compartment.
According to such a method, the pontoon 6 can be easily formed using the outer peripheral rim plate 5, and the pontoon type internal floating roof body 1a can be easily reinforced. The pontoon type internal floating roof body 1 a includes a deck 3 and a pontoon 6 provided on the outer periphery of the deck 3.

  When the pontoon 6 is formed on the outer peripheral part, the outer part of the pontoon type internal floating roof body 1a sinks and the center part of the deck 3 rises due to the weight of the pontoon 6 (increase in the outer peripheral part). 1a is deformed into a substantially square shape in cross section (see FIG. 2). For this reason, along with this modification, a deformation preventing structure for preventing the deformation of the pontoon type internal floating roof body 1a due to the weight of the pontoon 6 is formed in the pontoon type internal floating roof body 1a (see FIGS. 3 to 7). The deformation prevention structure can prevent deformation of the pontoon type internal floating roof body 1a, and can prevent deformation of the (pontoon type) internal floating roof 1. This deformation preventing structure has at least one of a buoyancy increasing structure for increasing the buoyancy of the outer peripheral portion where the pontoon 6 is formed and a pressing structure for pressing the center of the deck 3 of the floating roof body (FIG. 3 shows both). These structures are formed in the pontoon type internal floating roof body 1a.

  The holding structure is, for example, a structure in which a weight 16 and a holding portion such as a reinforcing plate / reinforcing material are formed on the pontoon type internal floating roof main body 1a, specifically, as shown in FIG. 3 and FIG. This is a structure in which a pressing part (weight 16 in this case) is installed (including fixing, placing, etc.) on the part. By installing a pressing portion, in particular, a weight 16 in the center portion of the deck 3, it is possible to easily suppress the bulge in the center of the deck 3. For this reason, a deformation | transformation of the pontoon type internal floating roof main body 1a (internal floating roof 1) can be prevented easily. The weight 16 is composed of iron plate, concrete, sand, remaining material / scrap, and the like. In addition, by holding down the deck 3, it is possible to prevent vapor gas from accumulating under this rise. The weight, size, shape, position, etc. of the holding part are considered whether to form another buoyancy increasing structure or the shape, size, weight, strength, etc. of the pontoon type internal floating roof body 1a, It determines suitably so that the pontoon type internal floating roof main body 1a (internal floating roof 1) may not deform | transform. When only the holding structure is formed, since all the construction work can be performed on the deck 3, it is an easy construction method.

  The buoyancy increasing structure includes, for example, a floating body structure (see FIGS. 3 and 4) in which a floating body 15 is formed below the pontoon 6, and a volume increasing structure in which the internal space volume below the pontoon 6 is increased (see FIGS. 5 and 5). 6)). Thus, when the buoyancy increasing structure is formed in the pontoon type internal floating roof main body 1a, the buoyancy of the outer peripheral portion of the pontoon 6 itself and the like increases, so the outer peripheral portion of the pontoon type internal floating roof main body 1a (that is, the pontoon 6) is downward. Can be prevented from sinking. Thereby, a deformation | transformation of the pontoon type internal floating roof main body 1a (internal floating roof 1) can be prevented. Moreover, the buoyancy increase structure can increase the buoyancy of the entire internal floating roof 1, and can prevent the internal floating roof 1 from sinking even if it is damaged. By forming the buoyancy increasing structure, in particular, by forming this buoyancy increasing structure in an annular shape or vertically and horizontally along the pontoon 6, the buoyancy balance and weight balance of the internal floating roof 1 are improved.

  The floating body structure is, for example, a structure in which an annular floating body 15 concentric with the pontoon 6 and formed along the pontoon 6 is installed (fixed and abutted) on the lower surface of the pontoon 6 (see FIGS. 3 and 4). ). The floating body 15 is a buoyancy body having a hollow inside made of, for example, aluminum or steel. The structure in which the floating body 15 is provided below the pontoon 6 may be, for example, a structure in which the floating body 15 is not a ring but a plurality of box-shaped floats, and this float is installed at a predetermined position below the pontoon 6. . The weight, size, shape, position, etc. of the floating body 15 are determined by examining whether or not to form another buoyancy increasing structure or a holding structure, and the shape, size, weight, etc. of the pontoon type internal floating roof body 1a. The pontoon type internal floating roof body 1a (internal floating roof 1) is appropriately determined in consideration of strength and the like. This structure has advantages such as easy adjustment of the buoyancy balance and simple formation. Then, the deck 3 can be attached without modification, and a predetermined buoyancy can be given to the outer peripheral portion. If the pan type internal floating roof body 101 is modified to the pontoon type internal floating roof body 1a after the floating body 15 is formed, the floating roof is modified to the pontoon type after adding rigidity to the floating roof with the floating body 15. This makes it easy to convert to a pontoon type.

  The volume increasing structure is, for example, a structure (see FIG. 5) in which the lower plate (the outer peripheral portion of the deck 3) of the pontoon 6 is inclined and moved downward to form a space 17 having a shape that maintains balance, or the pontoon 6 This is a structure (see FIG. 6) in which the lower plate (the outer periphery of the deck) is moved downward in parallel to form a space 18 having a shape that secures the volume. With this structure, the space 17 or the space 18 is formed in the pontoon type internal floating roof main body 1a, the internal space volume below the liquid level of the pontoon 6 is increased, and the buoyancy of the outer peripheral portion is increased. The volume increasing structure may have both of the above structures. By having at least one of the above two structures, the buoyancy of the pontoon can be reliably increased. The space 17 or 18 is formed in an annular shape along the pontoon 6, for example. The space 17 or 18 is constituted by, for example, a plurality of spaces that are formed in a balanced manner in the pontoon 6 such as vertically and horizontally symmetrically. The size, shape, position, etc. of the space 17 or 18 are determined as to whether to form another buoyancy increasing structure or a structure having a weight, and the shape, size, and size of the pontoon type internal floating roof body 1a, The pontoon type internal floating roof body 1a (internal floating roof 1) is appropriately determined in consideration of weight, strength, and the like.

  When a buoyancy increasing structure is first adopted and a holding structure is added for adjustment, a floating roof that is superior in balance can be obtained.

  As described above, according to the storage tank floating roof forming method according to the present embodiment, the storage tank floating roof forming method is prevented from being deformed by remodeling from the pan type to the pontoon type, and the strength and buoyancy are increased. Therefore, it can be widely applied industrially. And the floating roof of the storage tank according to this embodiment according to the present embodiment is applied to a wide range of industries because it becomes a floating roof of the storage tank which is prevented from being deformed by remodeling from the pan type to the pontoon type and has increased strength and buoyancy. It becomes possible.

It is explanatory drawing for demonstrating an example of the formation method of the internal floating roof of a floating roof storage tank with a fixed roof, and is a schematic cross section of the floating roof storage tank with a fixed roof in which the pan type internal floating roof is already formed in the storage tank FIG. It is explanatory drawing for demonstrating an example of the formation method of the internal floating roof of a floating roof type storage tank with a fixed roof, and the deformation | transformation at the time of remodeling a pan type internal floating roof main body into a pontoon type internal floating roof main body has occurred. It is a figure which shows the schematic cross section of the floating roof storage tank with a fixed roof shown. It is explanatory drawing for demonstrating an example of the formation method of the internal floating roof of a floating roof storage tank with a fixed roof, and is the outline of the floating roof storage tank with a fixed roof after forming a deformation | transformation prevention structure in the pontoon type internal floating roof main body. It is a figure which shows a cross section. It is a figure which shows an example of the internal floating roof of a floating roof type storage tank with a fixed roof. It is a figure which shows an example of the internal floating roof of a floating roof type storage tank with a fixed roof. It is a figure which shows an example of the internal floating roof of a floating roof type storage tank with a fixed roof. It is a figure which shows an example of the internal floating roof of a floating roof type storage tank with a fixed roof.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal floating roof 1a Pontoon type internal floating roof main body 3 Deck 4 Inner circumference rim board 5 Outer circumference rim board 6 Pontoon 7 Upper board 10 Floating roof storage tank 11 with a fixed roof Side board 12 Bottom board 13 Roof 15 Floating body 16 Weight 17 Space 18 Space 20 Liquid 21 Liquid surface 101 Pan type internal floating roof body 103 Deck 105 Outer rim plate

Claims (2)

A method for forming a floating roof of a storage tank, in which a pontoon is formed on the outer peripheral portion on the deck of an existing pan type floating roof main body, and a weight for preventing deformation due to the rising of the central portion of the deck is installed at the center of the upper surface of the deck, Alternatively, if the weight is not installed, a floating body that increases buoyancy and prevents deformation due to the sinking of the outer periphery of the deck is installed on the bottom surface of the deck corresponding to the pontoon formed on the outer periphery of the deck. When the roof is formed or the weight is not installed and the floating body is not installed, the lower plate of the pontoon is moved below the liquid level to increase the internal space volume below the pontoon liquid level. A method for forming a floating roof of a storage tank, characterized by increasing buoyancy and preventing deformation due to sinking of the outer periphery of the deck . A pontoon type floating roof body in which an existing pan type floating roof body is modified to form a pontoon on the outer periphery, and a buoyancy increasing structure for increasing the buoyancy of the outer periphery on which the pontoon is formed or the center of the top surface of the deck of the floating roof body A floating roof for a storage tank, comprising: at least one of a structure for installing a weight that suppresses deformation of the portion .

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