FI84532B - Plate-shaped construction unit for radiation protection - Google Patents

Description

84532

BUILDING SHEET UNIT FOR RADIATION PROTECTION

The present invention relates, for example, to a building board unit suitable for radiation protection of X-ray examination rooms 5, which is formed of a substantially homogeneous X-ray absorbing solid, the X-ray absorbing property of which is obtained by incorporating a structure-binding agent ingredient.

Exposure of the public to X-rays is considered undesirable due to the harmful effects of radiation on genetics and health. Likewise, X-rays may damage equipment and materials. For example, undeveloped film is sensitive to X-rays. For this reason, the aim is to direct the radiation from the X-ray equipment only to the desired target and to prevent the radiation from propagating elsewhere. In order to prevent the propagation of both primary radiation coming directly from the X-ray device and other, for example scattered, radiation, X-ray damping materials are used as sufficient layer strengths. Often, especially in new buildings, the wall thicknesses of X-ray spaces, such as concrete walls, are designed in such a way that X-rays cannot adversely spread to the environment. However, when constructing light-structure rooms, radiation protection must be provided separately. If spaces originally built for other purposes are taken as X-ray rooms, the walls of the X-ray examination room, often the walls, or even the ceiling, will not attenuate the radiation sufficiently and the attenuation in them must be improved to a sufficient level. In general, thick concrete walls become expensive and are avoided unless there is another technical advantage at the same time.

A fairly common way to prevent the propagation of X-rays into the environment 35 is to use lead to attenuate X-rays. For example, a 2mm layer of lead plate is sufficient to attenuate any stray radiation that may be generated in a conventional X-ray room to an acceptable level. However, installing a lead plate on the X-ray room wall is a rather cumbersome and high-precision job. For example, additional measures are required to ensure the radiation tightness of fastenings made with nails or screws. The protection thus made must still be covered with a building board in order to obtain a clean wall surface 5.

Since the lead plate handling is difficult and requires special skills, is developed by the interior wall panels having the construction levyelmentti, for example, a gypsum board is coated on one side of the lead plate 10. Such plates are thicker and stiffer than bare lead plates and in themselves form an unfinished finished wall surface. Radiation leaks from the joints between the plates are prevented by placing a strip of lead at the joint. However, the positions of the screws or nails 15 used for fastening have to be secured otherwise.

It is an object of the present invention to provide a novel, easy-to-install and easy-to-handle building board unit suitable for X-ray radiation protection which does not have the disadvantages described above.

To achieve this object, a building board unit suitable for X-ray radiation protection according to the invention is characterized in that the material composition of the building board unit is dimensioned so that the thickness of the board is substantially equal to or greater than the thickness of the steel layer providing the corresponding damping effect. The X-ray attenuation properties of the various elements are well known. In addition to the damping properties, the choice of absorbent component is also strongly influenced by the price and other suitability for the manufacture of the plate unit.

One advantage of such a building board is that it is clearly thicker than a lead board providing a corresponding damping. The material composition can be easily dimensioned so that the thickness of the plate is equal to or greater than the thickness of the steel layer providing the corresponding damping effect, whereby the nailing point is not worse in terms of X-ray damping than the plate elsewhere. Likewise, "extra 3,84532" nails can be punched into the finished protective wall, for example for fixing devices, without the need to ensure radiation tightness separately. Essential to the protection of a plate having a certain damping coefficient is the thickness of the plate. Rays 5 other than perpendicular to the plate travel a longer distance in the plate than its thickness and are correspondingly more attenuated.

Another advantage is that a plate made of uniforms is easier to process than a plate with two or more clearly different structural layers. This advantage arises when not all the dimensions of the room in which the plate units are installed are divisible by the modulus dimension of the plate, and also, for example, when making electrical cable entries.

It can also be mentioned as an advantage that the sheet metal units according to the invention, when installed, provide a finished wall surface without finishing and that this is achieved with a smaller amount of work than using known solutions.

The building board unit according to the invention is particularly well suited for use in lightweight structural solutions and also for spaces whose purpose is changed to an X-ray examination space.

Other preferred embodiments of the invention are characterized by what is set forth in the claims below.

The invention will now be described in more detail with reference to the accompanying drawings, in which Figures 1a and Ib show the attachment of a lead plate to the radiation attenuation of a wall,

Figure 2 shows a known plate element solution for radiation attenuation of a wall,

Figure 3 shows an example of a joint of two building board units according to one embodiment of the invention, 35 5 4 84532

Figure 4 shows an example of a joint of two building board units according to another embodiment of the invention.

Figures 1a and Ib show a detail of the installation of a wall-mounted lead plate, in which the seam 1 of two thinner lead plates is nailed to the wall. In the seam, the lead plates 2 are placed on top of each other nailed with nails 3. The edge 4 of the top-10 seam plate is then turned in the seam to cover the bases of the nails 3. This achieves a sealed structure in terms of radiation protection. However, installation is time consuming, especially because of the covering of the nail. In order to obtain a clean surface, a building board or the like is also mounted on such a wall surface, whereby damage to the lead is possible.

Figure 2 shows a known plate element solution. The lead plate 5 is attached to the rear surface of the building plate 6. The plates are fixed at their edges to a special fixing base 7, in which 20 there is a lead plate 5 to prevent radiation leakage from the seam.

Figure 3 shows a reduced cross-section of the seam point 10 of two plate units according to the invention 8.9. The male edges 8 'of the plate unit 8 are convex and the female edge 9' of the incoming plate unit 9 is concave. By making the radius of curvature of the convex edge somewhat smaller than that of the concave, the plates are placed firmly against each other. Since the cross-section of the seam is curved, the free distance of the X-ray hitting the seam is relatively short and there is a sufficiently thick layer of damping agent in the radial direction in front of the X-ray to provide the designed damping. A piece of damping material, such as a lead plate strip 18, can also be placed behind the seam. The plate can be somewhat thinned at its edge, so that the strip placed behind the seam 35 does not lift the plate off the wall. Ensuring the radiation tightness of the joint is necessary, especially if for some reason the joints do not seal sufficiently against each other. This is the case, for example, in corners where the shaped surface of the edge is against the outer surface of the plate. The plates are fastened through by nailing to the wall structure 12 below. The nails 13 are made of at least as good an X-ray absorbing material as the plate, so that the point of the nail is not inferior to the other parts of the wall surface thus made. In addition to nailing, another method of fastening can also be used, for example screw fastening or gluing.

Figure 4 is a cross-sectional view of the seam point 16 of plate units 14, 15 having a different shape. The plate units have been constructed of a new inner wall by nailing the plates to the collar 17. The material strength of the X-ray hitting the seam is sufficient to would be quite long with respect to the thickness 15 of the plate, since the edges 14 ', 15' of the plates are formed such that the cross section of the seam is a broken line. By pushing the shape edges of the plate units against each other, a good radiation density is achieved, because the thickness of the plate unit is clearly larger than the gap that may remain in the seam. In the figures, only the edge parts of the building board-one-20 ropes to which the functions of the installation phase are directed are shown.

The sheet unit of the invention was prepared as an experiment by casting a mixture of barium-25 sulfate as the X-ray absorbing component and gypsum, approximately the same amount of each, as the structure-binding component. This plate stayed well together and was easy to work with. By varying the composition of the material, different sheets with mechanical properties can be made. Likewise, the thickness 30 of the damping layer having the same damping can be adjusted in the manufacturing step by the relationship between the absorbent component and other raw materials, or sheets of the same thickness having different damping coefficients can be made. In a broader fabrication, the sheet units can be made to be made of gypsum board like a test piece, but there is nothing to prevent a gypsum board-like sheet made with a radiation absorbing component as one filler or a board with cement as a binder. In addition to barium sulfate, 6,84532 is excellently suitable for use as an X-ray attenuating ingredient, e.g. lead chemical compounds or lead flour or lead-containing minerals.

It will be apparent to those skilled in the art that the various embodiments of the invention are not limited to the above examples but may vary within the scope of the claims below.

Claims (9)

1. A building plate unit for, for example, radiation protection in an X-ray examination room, which building plate unit (8,9,14,15) is made of a substantially homogeneous, X-ray radiation absorbing solid, the X-ray absorbing property of which is obtained by providing in the plate unit blank composition and structure constituents include a substance which strongly absorbs X-ray radiation, characterized in that the structure composition of the structural plate assembly (8, 9, 14, 15) is so dimensioned that the thickness of the plate is substantially the same or greater than the thickness of an adjusting plate having the same damping effect. 2. A building board unit according to claim 1, characterized in that the highly X-ray absorbing substance component contains a substantial amount of barium sulphate or lead or chemical lead compounds or of a mixture of at least two substances mentioned herein. 20 3. A building board unit according to any one of the preceding claims, characterized in that gypsum or cement or glue or resin is used as one of the binding constituents of the composition. 25 Building plate assembly according to any of the above claims, characterized in that the edges (8 ', 9', 14 ', 15') of the building plate unit (8 ', 9', 14 ', 15') are so designed that at the joint (10, 16) of two plate units, assembled edge to edge, the material thickness encountered by the beam passing through the plate is substantially the same or greater than the thickness of the plate. 5. The building plate unit according to any of the above claims, characterized in that the plate unit at least at one edge is slightly thinner than the other parts of the plate unit. 10 84532 6. A building board unit according to any one of the preceding claims, characterized in that the edges of the plate unit (8 ', 9') in their cross section are considerably bent, and that of the opposite edges, one is bent towards the plate and the other from the plate. The building plate unit according to any of the above claims, characterized in that the bending radius of the convex edge (8 ') is smaller than the concave edge (9 *). 8. A building board unit according to any one of the preceding claims, characterized in that the edges of the plate unit (14 ', 15') are in the form of a breaking line. 15