FR2666442A1 - Machine for replacing doors for access to irradiated zones, and use of such a machine - Google Patents

Abstract

It comprises a chamber (1) provided with an opening (2) and a shuttle system (7, 8, 10). Plates (15) to which the doors (20, 25) are attached can be advanced into the opening or retracted. The shuttle system makes it possible to place them in turn in front of the opening. A system of sealing gaskets (22, 27, 29) makes it possible not to break the confinement with respect to the outside and limits the irradiation inside the chamber (1). Decontamination (31, 32, 53) is then easy.

Description

ACCESS DOOR REPLACEMENT MACHINE

  TO IRRADIATED AREAS, AND USE OF SUCH A MACHINE

DESCRIPTION

  The invention relates to a machine for replacing access doors to irradiated areas,

  and the use of such a machine.

  Such a machine is described in French patent 2,544,542 It is designed to operate from the outside, and it has a mouthpiece which is pressed against an opening on a biological protection wall The irradiated zone extends into a cell located behind the biological protection wall and delimited by a second wall, waterproof but permeable to radiation, which is provided with access doors to the irradiated area These doors are frequently

  fitted with devices which should be replaced periodically

  only, such as sensors or agitators if a gas circulates in the cell The contaminating product has the ability to flow out of the cell as soon as the door is removed This is why the door replacement machine must have the watertightness necessary to stop this flow and at no time require the communication of the area

irradiated with the outside.

  The machine contains a rotating shuttle mechanism which comprises two door supports in the form of cells provided with means for gripping the doors.

  A first support is brought in front of the opening.

  ture of the biological protection wall The door to be extracted is gripped then removed and held in the cell The Rotation of the shuttle mechanism

  then allows to bring another support in front of the

  verture of the biological protection wall, the cell of which contains a replacement door This door is inserted into the opening up to the cell wall The machine must fulfill the biological protection and sealing functions, which implies that it is heavy and cumbersome because

  the large amount of radiation absorbing material

  placed around the shuttle mechanism.

  Sealing can only be ensured with numerous seals, which do not offer total safety. Finally, the use of such a machine requires providing the cell with sleeves which connect the opening of the wall. of biological protection at the opening of the cell on which the door is arranged The door is then fixed to a rod which extends in the sleeve Before using the machine, one pulls on the rod to slide the door in the sleeve until close to the protective wall

  biological The rod is then removed from the door.

  Of course, the door and the sleeve are formed in such a way that the seal is never broken. This whole construction is complicated and costly We sometimes even have to locally deform the cells by bringing the doors closer to the biological protection wall to avoid

sleeves too long.

  The machine according to the invention therefore originates from the desire to avoid this complexity in

  installation and process The fundamental originality

  tale is that the new machine is used between the biological protection wall and the cell wall The machine no longer has a protective role

  organic to hold and simply needs to be waterproof.

  As its structure is very simplified and that slight leaks are less serious than in the case of an outside machine, the seal

  can be ensured much more simply.

  It is in particular possible to dispense with the multiple-effect seal, commonly used in

  this kind of technique, which is plated around the-

  Greenery of the biological protection wall and whose special shape guarantees the absence of contamination of the external areas With the new machine, a

  slight contamination is accepted but decontamination

  Then the company is enough to bring a pro-

  allowable loan around the cell opening.

  The invention therefore relates to a machine

  replacement of access doors to conta-

  mined, comprising an enclosure provided with an opening and containing two door handling systems, each door handling system comprising a door support and means for locking the door to the support, the enclosure further containing a mechanism for shuttle on which the door supports depend and which is constituted so as to be able to place alternately each of the door supports in the opening, the machine further comprising a first seal disposed around the opening and creating

  a seal between the enclosure and a delimited wall

  as a contaminated area, characterized in that it comprises a second seal disposed in the opening and creating a seal between the enclosure and a support placed in the opening, a third seal disposed on said support and creating a seal between the door and said support, as well as a device for decontamination of a sealed volume limited by the

three joints.

  The invention will now be described in more detail with the aid of the following figures, which are given by way of illustration and not limitation: FIG. 1 is an overview of the invention; Figure 2 is an overview of another embodiment of the invention;

  Figure 3 details the sealing device

cheeness;

  FIG. 4 represents a diagram of construction

  tution of access door; FIG. 5 represents the environment of the invention; and Figure 6 shows a front view

door supports.

  The first realization of The machine

  includes a box or enclosure 1 with an opening

  ture 2 on one side Enclosure 1 contains two systems

  identical door handling temes 3, each occupying substantially half the volume of the enclosure and each of which comprises two Archimedes screws for Llèles 4 The Archimedes screws 4 are oriented with an axis corresponding to the direction of passage through the opening 2 They are joined between the by one end to a first swivel bar 5 and by their other end to a second swivel bar 6 The second swivel bar 6 is subject to a pivot 7 fixed to the enclosure 1 not far from the opening

  2, while the first swivel bar 5 is subject to

  attached to a movable pivot 8 which crosses the face of the

  belt 1 opposite the opening 2, which is a cover

9 detachable.

  A first motor 10 fixed to the outside

  of the cover 9 drives the movable pivot 8.

  The two bars 5 and 6 pivot and one of the two door handling systems 3 passes in front of the opening 2 at each half-turn In this position, a square section end 11 of the Archimedes screws 4 meshes in a c Labot 12 at the end of an axis 13 pivoting in the cover 9 along the axis of the Archimedes screws 4 A second motor 14 fixed to the outside of the cover 9 drives the two axes

  13 in one movement thanks to a compressed transmission

gimbals 43.

  A panel 15 is hung on the Archi screws

  mède 4 of each door handling system 3 We can distinguish a rear flange 16 carrying engagement nuts for Archimedes screws 4, a cylindrical zone 17 extending from the rear flange 16 towards the opening 2, and a substantially planar closing plate 18, surrounded by the cylindrical zone 17 The cylindrical zone 17 and the closing plate 18 delimit towards the front a

door housing cavity 19.

  In the state where the machine has been shown, one of the panels 15 has been moved to the very end of the Archimedes screws 4 which support it so as to obstruct the opening 2, while the other panel is retracted to the inside the enclosure 1, near the first swivel bar 5 It carries a door 20 housed in the cavity 19 and which carries itself

  a component such as a measuring device 21.

  Several systems can be used for

  block a door 20 on a panel 15 We can consider

  manage the use of a small pneumatic jack 44 in two states, articulated on the internal face of the closure plate 18, and the displacement of the rod 45 of which controls the rotation of an axis 46 which drives a disc 47 in front of the external face of the closing plate 18 Means 48 fixed to the periphery of the disc 47 move rods 49 which are articulated to them and which slide in bearings 50 on the panel

  18 the end of the rods 49 penetrates into recesses

  unrepresented elements of the door 20 and thus blocks it against the closure plate 18 This system, which is also shown in FIG. 6, is present on the two panels 15 but has only been designed

  on one so as not to overload Figure 1.

  In this design, the handling systems

  door 3 are subjected to a circu-

  space which imposes a certain overall width in the enclosure 1 For certain applications, the space constraints may require a narrower enclosure such as that which is referenced by

1 'in Figure 2-

  The above description can generally

  be transposed to this embodiment except for the shuttle mechanism by which

  moves door handling systems 3.

  This mechanism here consists in particular of two sliding bars 5 'and 6' which replace the pivoting bars 5 and 6 The second sliding bar 6 'is moved on fixed supports 7' on the enclosure 1 'while the first sliding bar 5 ′ comprises a rack on which a pinion 51 meshes at the end of the movable pivot 8 Support systems not shown fixed to the enclosure 1 ′ maintain

  the first sliding bar 5 'against the pinion 51.

  This achievement involves placing the open-

  ture 2 towards the middle in enclosure I while two cells are provided on either side to accommodate that of the door handling systems

who is not employed.

  We now refer to Figure 3.

  A first seal 22 is disposed around the opening 2 on a front face 23 of the enclosure 1 and comes to be pressed against a cell wall 24, around a door 25 for access to an irradiated area 26 A second seal 27 is placed on the outside of the cylindrical zone 17 and is pressed against the edge 28 of the opening 2 when the panel 15 is advanced A third seal 29 flat disposed on the face plate outer

  closure 18 and that the front part of the cylinder zone

  drique 17 surrounds is pressed against a door 25 to be replaced while a fourth seal 30 is pressed between the front face of the door 25 and the cell wall 24 The four seals 22, 27, 29 and 30 delimit a sealed annular volume 52 with the door 25, the cell wall 24,

Panel 15 and enclosure 1.

  A liquid circuit opens into this volume

  annular 52 There is shown in the figure a canali-

  sation 31 pierced through the enclosure 1 and which ends on an injection pump 32 and a reservoir of Liquid 53 at its other end There is an identical circuit, composed of a pipe, a suction pump and a reservoir of Liquid at the diametrically opposite location of the annular volume 52 The assembly makes it possible to circulate a decontamination fluid in the annular volume 52 using the two pumps By the way, there is one of the nuts 33 whose is fitted with the rear flange 16 for

  engagement with Archimedes' screws 4.

  Finally, the cell wall 24 is provided

  of pawns 34 whose shape is complementary to the hollow

  elements 35 of enclosure 1 to allow centering

  correct opening 2 around door 25.

  The door replacement process consists first of all in placing the enclosure 1 on the cell wall 24 by correctly fitting the pins 34 in the recesses 35 The seals 22 and 29 are pressed against the cell wall 24 and the door 25 Ce pressing can be accomplished by the machine's own weight

  if the cell wall 24 is a ceiling Otherwise, the

  belt 1 can be clamped against the cell wall

  24 or pressed by any mechanical means.

  Locking is then carried out.

  the door 25 on the panel 15 using the pneumatic cylinder

  tick 44, after which the Archimedes' screws 4 are set in motion to lift the panel 15 and remove the door 25 The contaminated content of the irradiated zone 26 can be introduced into the enclosure

  1 The seals 22 and 29, however, prevent it from leaking out.

  Outside and in front of the closing plate 18 Without moving the enclosure 1 of the cell wall 24, the shuttle mechanism rotates by a half-turn so as to place the replacement door 20 in front of the opening 2 The panel 15 is then advanced until the door 20 is placed on the irradiated area 26 The door 20 is then unlocked from the panel 15 The sealed annular volume 52 has however been reconstituted,

  so that it is decontaminated by injecting it

  so much washing liquid which is then sucked up.

  The enclosure 1 can then be removed.

  The panel 15 remains in the state shown to completely isolate the contaminated content of the enclosure 1

  from the outside, thanks to the seal 27 which obstructs hermetic

only the opening 2.

  The contaminated doors such as 25 have left enclosure 1 after having placed the machine on a container having a shape similar to that of the cell wall 24 The contaminated door is placed on the opening of the container in the manner described, then decontamination is carried out and

the machine is removed.

  In many cases, the total weight of the door and of the possible measuring device 21 is sufficient to achieve correct support on the cell wall 24 Otherwise, it is possible to use a system such as that of FIG. 4 A stirrup 39 is placed on two diametrically opposed centering pins 34 A pressing pad 40 is placed on the door

above the stirrup 38.

  A threaded shaft 41 completed by a flywheel 42 is engaged in a thread in the stirrup 39 of

  so that its end touches the pressure shoe

  sage 40 and exerts a force on it, which keeps the door 20 in place In this design, the centering pins 34 are terminated by threads which extend through holes in the stirrup 39, and nuts screwed onto these threads maintain

stirrup 39.

  FIG. 5 shows the way in which the machine is used. A biological protection wall 55 surrounds the cell wall 24 Two rails 56 are fixed against the internal face of the biological protection wall 55, and a carriage 57 rolls on them Two slides 58 on the carriage 57 allow a lower carriage 59 to roll perpendicular to the

rails 56.

  The enclosure 1 is located at the end of the rod of a jack 60 whose cylinder is fixed to the lower carriage 59 The extension of the jack rod makes it possible to press the machine against the cell wall 24 A camera 61 monitors the volume between the two walls 24 and 55 and indicates whether the machine is placed in the desired location The rails 56 can

  end at their opposite end to an airlock o

  reduce intervention on the machine This is notably

  where the containers receiving the contaminated doors

  born or new doors are put in place.

  FIG. 5 represents a device placed on rails 56 and where the cell wall is a ceiling, as is the case in the previous figures This device could be used with rails 56 and cell walls 24

of any orientation.

  The motors 10 and 14 are controlled, like the pneumatic cylinder 44, by means of electric cables or the like which terminate outside the biological protection wall and

  have not been shown for convenience.

Claims (5)

  1 door replacement machine (25) for access to contaminated areas (26), comprising a   enclosure with an opening and containing two systems   door handling elements (3), each door handling system comprising a door support (15) and means for locking the door to the support, the enclosure further containing a shuttle mechanism (7, 8, 10 ) on which the door supports depend and which is constituted so as to be able to place alternately each of the door supports in the opening (2), the machine further comprising a first seal (22) disposed around the opening and creating a seal between the enclosure and a wall (24) delimiting a contaminated area, characterized in that it comprises a second seal (27) disposed in the opening and creating a seal between the enclosure and a support placed in the opening, a third seal (29) disposed on said support and creating a seal between the door and said support, as well as a decontamination device (31) of a limited sealed volume (52) by the three joints.   2 Machine according to claim 1, character-   laughing at the fact that the third seal is a flat seal   (29) disposed at the bottom of a support cavity.   3 Machine according to any one of the res-   dications 1 or 2, characterized in that the enclosure is provided with centering means (35) of the opening around the door.   4 Machine according to any one of the res-   dications 1 to 3, characterized in that the shuttle mechanism comprises a rotating structure for bringing each support indifferently in front of the opening and motor means for sliding the supports in the opening (figure 1).   Machine according to any one of Claims 1 to 3, characterized in that the shuttle mechanism comprises a structure movable in alternative translation to bring each support indifferently before the opening and motor means for making   slide the supports into the opening (figure 2).   6 Use of a machine according to one   any of the preceding claims in a   installation composed of an external biological protection wall (55) and of the wall (24) delimiting the contaminated zone, characterized in that the machine   is used between the two walls.