JPH1182874A - Split cylinder type heat insulating radiation shielding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a split cylinder type heat insulating radiation shielding device in which shielding material can be removably built in a short time without lowering heat insulating performance and radiation shielding performance. SOLUTION: In a split cylinder type heat insulating device with semicircular shielding material B made of lead, disposed at a laminated intermediate part of heat insulating material 2 charged in a cylindrical metal case body A, an inner surface plate a1 , an outer surface plate a2 and end face plates a3 formed of low heat conductive steel plates are connected by L-shape fittings C1 , C3 , and the contact part of the shielding material B with the end face plates a3 are held between L-shape holding fittings C2 , C4 connected to the L-shape fittings C1 , C3 . The shielding material can therefore be built in removably in a short time without lowering heat insulating performance and radiating performance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a cylindrical split type adiabatic radiation shielding apparatus which is suitable mainly for use in piping, equipment, containers and the like of a nuclear power plant.

[0002]

2. Description of the Related Art In a nuclear power plant, it is legally obliged to conduct inspections during the service period. Therefore, an insulation device attached to a pipe of the plant is provided with a radiation exposure amount for maintenance work under radiation. In order to minimize it, a cylindrical split type heat insulation device that is easy to attach and detach is used.

[0003] In the above-mentioned cylindrical split type heat insulating device, a heat insulating material such as rock wool, glass wool or the like is provided in a cylindrical split metal box in which a hollow cylindrical body is vertically divided in half so as to hold a pipe. Aluminum foil that has been processed and wrinkled,
There is known a configuration in which a heat insulating material such as a stainless steel foil is filled and arranged in a laminated manner.

[0004]

Recently, in a nuclear power plant, in order to ensure the safety of workers and improve the working environment, a shielding member made of a lead plate for shielding radiation such as gamma rays is provided inside the metal box. A split-type heat insulation device incorporated in a rocket is often used.

A conventional heat insulating device incorporating a shielding material uses an end plate made of stainless steel, and installs the shielding material on the innermost layer of a cylindrically divided box body, and attaches only the outside of the shielding material with a clamp, In the case of supporting in the middle of the layer, a configuration is known in which a holding member is welded to a stainless steel end plate, and the shielding plate is held by the holding member.

Further, in order to improve the radiation shielding performance, the thickness of the shielding material tends to be larger than that of the related art. However, since the shielding material is a heavy metal, the weight increases, so that the number of cylinder divisions is increased in consideration of handling properties, but if the number of divisions increases, the cylindrical division type metal box is formed. Heat loss from the end plates (plate members located at both ends in the circumferential direction and the axial direction of the cylindrical box) increases, and the heat insulation performance decreases.

As a measure for suppressing the heat loss at the end face plate, there is a method of using a low heat conductive steel sheet such as a stainless steel fiber sintered plate or a foamed metal plate as the end face plate. However, since the low heat conductive steel sheet has a porous structure, there is a problem that the weldability is poor, and the heavy metal shielding material cannot be firmly supported.

The main object of the present invention is to provide a cylindrically divided heat-insulating radiation shielding apparatus in which a shielding material can be detachably incorporated in a short time without deteriorating the heat-insulating performance and the radiation shielding performance.

[0009]

SUMMARY OF THE INVENTION The present invention provides a metal box having a divided cylindrical shape, comprising an inner plate, an outer plate, end plates located at both ends in the circumferential direction, and end plates located at both ends in the axial direction. The end plates are made of a porous structure of low thermal conductive steel, and a heat insulating material is filled and arranged in the box, and a semicircular radiation shielding material is provided at an intermediate portion of the filled layer of the heat insulating material. A cylindrical split type adiabatic radiation shielding device, wherein the arc-shaped radiation shielding material is in contact with an end plate in a circumferential direction of the box and an end in contact with an end plate in an axial direction of the box. The gist is that the portion is configured to be held by holding metal fittings respectively connected to the inner surface plate and the outer surface plate.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As a preferred embodiment of the present invention, as shown in FIGS.
Are formed by an arc-shaped inner plate a ₁ , an outer plate a ₂ , end plates a ₃ , a ₃ located at both ends in the circumferential direction, and end plates a ₄ , a ₄ located at both ends in the axial direction, A heat insulating material made of rock wool, glass wool or thin metal plate 2 is filled and arranged in the inside thereof, and a semi-arc-shaped lead shielding material B is arranged in the lamination, and this shielding material B is an end plate a _The ends that abut against ₃ are two L-shaped fittings C ₁ , C ₃ and L-shaped holding fittings C ₂ , C ₄
A structure for clamping the box side via the connecting fitting comprising a, also ends shielding material B abuts against the end plates a ₄ is 2
It is configured to be clamped on the box body side via a connecting fitting composed of two L-shaped fittings C ₅ and C ₇ and two L-shaped holding fittings C ₆ and C ₈ .

[0011]

1 to 6 show an embodiment of the present invention. 1 to 6, A is a semi-cylindrical metal box body obtained by vertically dividing a hollow cylinder into half, and has an arc-shaped inner plate a ₁ , an arc-shaped outer plate a ₂ , and both ends in the circumferential direction. End plate a ₃ ,
a ₃ , and end plates a ₄ , a ₄ located at both ends in the axial direction
Of which the inner plate a ₁ and the outer plate a ₂ are made of stainless steel, and the end plates a ₃ and a ₄ are made of a porous structure low thermal conductive steel plate obtained by sintering stainless steel fibers under a high temperature vacuum. I have.

[0012] B is to be located in a semi-tubular box body intermediate a lead made of shielding material which is bent in a semicircular arc shape with a predetermined radius of curvature, as shown in FIG. 2, end plates a ₃ , A ₃
Is held in the box by the following means via a connecting fitting composed of two L-shaped fittings C ₁ and C ₃ and two L-shaped holding fittings C ₂ and C ₄ . .

The procedure for assembling the shield on the box side includes:
First, the inner plate a ₁ and end plates a ₃ as tether the L-shaped fitting C _1, coupling each other by spot welding. Thereafter, the L-type clamping bracket C ₂ bind with spot welded to the L-shaped bracket C _1. On the other hand, to couple the L-shaped fitting C ₃ serving as a connecting member to the end plate a ₃ by spot welding.

[0014] Then on the inner surface plate a _1, after filling arranged in layers a heat insulating material made of a metal plate 2 of specific shape shown in FIGS. 4 to 6, the shielding member B of said semicircular L Katakyoji Hardware C ₂
Placed temporarily in contact with state, the outer shielding material B so as to sandwich the L-type clamping bracket C _4, is mounted above L
Binds a type fitting C ₃ and spot welding. Thereafter, a heat insulating material made of the metal plate 2 is further filled and arranged on the outer surface of the shielding material B in a laminated manner, and an outer surface plate a ₂ is superposed on the front side thereof, and L
Bound by a rivet (not shown) to the mold bracket C _3.

On the other hand, as shown in FIG. 3, two L-shaped fittings C ₅ and C ₇ and two L-shaped fittings C ₅ and C ₇ are also provided at the end of the semicircular shielding material B where the axial end face abuts against the end face plate a _4. Clamping fittings C ₆ , C ₈
And is held in the box by the same means as described above.

That is, the inner plate a ₁ and the end plate a ₄ are connected to the L-shaped
As ₅ ties bind each other by spot welding, thereafter, combining the L-shaped clamping bracket C ₆ to the L-shaped fitting C ₅ by spot welding. On the other hand, to couple the L-shaped fitting C ₇ serving as a connecting material of the outer surface plate a ₂ on the end face plate a ₄ by spot welding.

Next, after the above-mentioned heat insulating material made of the metal plate 2 is filled and arranged in a laminated manner, the semicircular shielding material B is temporarily placed in contact with the L-shaped holding member C ₆ , and the shielding material B is placed.
The outer so as to sandwich the L-type clamping bracket C _8, bind with it Aru L-shaped fitting C ₇ and spot welding the attachment to the first. Thereafter, a heat insulating material made of the metal plate 2 is further filled and arranged on the outer surface of the shielding material B in a laminated manner, and the outer surface plate a
Superimposing _2, binds to the L-shaped fitting C ₇ at rivet (not shown).

Thus, according to the above-described structure, the heavy metal semicircular arc-shaped shielding member housed in the cylindrical divided box body has a porous structure located at both ends in the circumferential direction and the axial direction of the box body. It is stably held on the low thermal conductive steel sheet by means not depending on welding. In this case, the mounting positions of the L-shaped clamping members C ₂ and C ₄ and the L-shaped clamping members C ₆ and C ₈ can be adjusted according to the dimensions of the shielding plate when clamping the shielding plate.

The thin metal plate 2 used as a heat insulating material to be stacked and filled in the box A constituting the cylindrical split type adiabatic radiation shielding device, reflects radiant heat on the surface thereof, and between the thin metal plates. The formed air layer serves as a heat insulating layer exhibiting a heat insulating effect, and has a thickness of 0.05 mm.
A stainless steel plate and an aluminum plate of up to 0.1 mm are used.

The metal sheet 2 has V-shaped ribs 2a and 2b which are embossed in a lattice at a required interval, and the ribs 2a and 2b.
A conical projection 2c is provided at the center of the lattice plane section defined by a and 2b and is embossed higher than the rib. The V-shaped ribs 2a and 2b pressed in a lattice shape on the metal sheet 2 are important factors for holding the metal sheet 2 in a polygonal shape concentrically with the semi-cylindrical box. That is, when a metal thin plate is filled in a semi-cylindrical box body in a stacked state, it is easy to bend at the axial rib 2a of the box body, and the circumferential rib 2b becomes resistant to bending, and in the middle of the axial rib. Since it is difficult to bend, the metal sheet can be easily bent and held in a polygonal shape concentric with the semi-cylindrical box. The interval between the V-shaped ribs 2a and 2b provided in the metal thin plate 2 in a lattice pattern is 10 to 70.
mm and a height of the V-shaped rib of about 1 mm is suitable for piping.

The conical projections 2c serve to hold the metal thin plates at a constant interval, and it is preferable that the diameter of the bottom of the cone is about 10 to 15 mm and the height is about 3 to 8 mm in terms of heat insulation performance. It is desirable to reduce the number of the conical protrusions 2c as much as possible from the viewpoint of heat insulation performance. However, if the number is too small, the metal thin plates may come into contact with each other and have an adverse effect. Therefore, the interval between conical projections is 50-70m
m is appropriate.

It is preferable that the conical projections 2c are provided at different phase portions between the laminated metal sheets. For example, as shown in FIG. 4, when using a metal thin plate in which the pitch of the projections 2c provided on the lattice surface section defined by the V-shaped ribs 2a and 2b is different in the orthogonal direction, the metal thin plate is used. By turning 90 degrees and stacking sequentially, or by simply stacking by sequentially shifting the pitch of the projections by 1/2 in the axial direction of the semi-cylindrical box, the adjacent metal sheet metal projections are set to different phases. Can be done easily.
In the embodiment shown in FIG. 6, a state in which metal thin plates are stacked by the latter means is shown.

With the above construction, the strength of the metal sheet itself is improved, deformation such as warping due to heat is eliminated, heat conduction due to contact between the metal sheets is minimized, and the surface of the metal sheet is reduced. The effect of reflecting the radiant heat effectively acts, and an excellent heat insulating effect is exhibited.

[0024]

As described above in detail, according to the present invention, a cylindrical split type heat-insulating radiation shielding apparatus capable of detachably incorporating a shielding material in a short time without deteriorating the heat insulating performance and radiation performance. Is obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a cylindrical split type adiabatic radiation shielding apparatus showing one embodiment of the present invention.

FIG. 2 is an enlarged sectional view taken along line XX of FIG.

FIG. 3 is a sectional view taken along line YY of FIG. 2;

FIG. 4 is a plan view of a metal thin plate.

FIG. 5 is a side view of a metal sheet.

FIG. 6 is a cross-sectional view of a laminated metal sheet.

[Explanation of symbols]

A Half-cylindrical metal box a ₁ Inner plate a ₂ Outer plate a ₃ , a ₄ End plate B Radiation shielding material C ₁ , C ₃ , C ₅ , C ₇ Angled L-shaped bracket C ₂ , C ₄ , C ₆ , C ₈ Angled L-shaped clamping bracket 2 Metal sheet 2a, 2b V-shaped rib 2c Conical projection

Claims (3)

[Claims] 1. A metal box of a cylindrical split type is formed of an inner plate, an outer plate, end plates located at both ends in the circumferential direction, and end plates located at both ends in the axial direction, and each of the end plates is provided. Is a porous structure of a low thermal conductive steel sheet, a heat insulating material is filled and arranged in the box, and a semicircular radiation shielding material is provided in a middle portion of the filled layer of the heat insulating material. Wherein the arc-shaped radiation shielding material has an end contacting the circumferential end plate of the box and an end contacting the axial end plate of the box, the inner plate and the outer plate, respectively. A cylindrical split type heat-insulating radiation shielding device characterized in that it is configured to be clamped by a coupled clamping fitting. 2. An inner face plate and an end face plate are connected by spot welding via a first L-shaped fitting, a second L-shaped holding fitting is connected to the first L-shaped fitting by spot welding, and a third L-shaped fitting is separately provided on the end face plate. Are connected by spot welding, and the second L-shaped clamping metal is connected to the third L-shaped metal by spot welding.
The cylindrical split-type adiabatic radiation shielding device according to claim 1, wherein a radiation shielding material is sandwiched between the die clamping metal. 3. The heat insulating material is provided with ribs stamped in a lattice shape on a thin metal plate, and projections which are stamped higher than the ribs on a surface section defined by the lattice ribs. The cylindrically divided adiabatic radiation shielding apparatus according to claim 1, wherein the apparatus is configured.