Patent Number: 046801669
Section: description

In the drawings, details and devices which are not required for the purposes of understanding the invention are omitted for the sake of improved clarity. DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION Referring to FIG. 1, two conduit ends 7 and 9 of respective conduit lengths 8 and 10 are bent through 90.degree. and terminate in end flanges 11 and 13, respectively, welded thereto. The conduit ends 7 and 9 extend from a rack or frame structure 5 mounted in a large-area cell 40 for reprocessing irradiated nuclear fuel. The frame structure 5 accommodates process components (not shown herein) for the chemical reprocessing of nuclear fuels. The two end flanges 11 and 13 are disposed in a common horizontal plane and are connected together by a conduit connecting unit 15 having a conduit portion 17 thereby forming a continuous conduit made up of conduit portion 17 and conduit lengths 8 and 10. which carries the medium to be processed. The conduit connecting unit 15 is of a bent configuration for the purposes of giving a better position for the center of gravity thereof and which has end flanges 19 and 21 which are welded thereon at the respective ends thereof. The two end flanges 19 and 21 are each connected to a respective end flanges 11 and 13 of the conduits ends 7 and 9 on the rack side, by threaded bolts 23. A bracket 25 is attached to the conduit connecting unit 15 in an aligned position relative to the center of gravity. At its center the bracket 25 has a carrying eye or lug 27 which is welded thereto and which can be engaged by a load hook of a lifting device. At their sides, the end flanges 19 and 21 have respective guide pins 29 and 31 welded thereto. The guide pins 29 and 31 are parallel to the respective axes of the throughflow bores of the end flanges 19 and 21. Each guide pin 29 and 31 lies in respective guide cradles 33 which are suitably mounted laterally on the respective end flanges 11 and 13. At the rearward end, towards the rack 5, the guide cradles 33 terminate in respective catch rings 35. Each guide pin 29 and 31 lies in the corresponding guide cradle 33 and also projects through the corresponding catch ring 35 and beyond the same. FIG. 2 shows that the pair of flanges 13 and 21 couples a conduit end 9 and conduit portion 17 which extend from the center point of the pair of flanges 13 and 21. Arranged around the conduit portion 17 are three threaded bolts 23 which have their actuating hexagon away from the end flange side of the conduit connecting unit. Provided in the end flange 21 are through bores while the corresponding threaded bores are provided in the end flange 13. The threaded bolts 23 are secured on the back of the end flange 13 by means of suitable nuts 41. FIG. 3 shows the guide pin 31 with the threaded bolts 23 removed. The modified embodiment shown in FIG. 4 is used for connecting conduit connections which are not arranged in parallel-axial relationship to each other. By means of the centering and manipulating arrangement of which FIG. 4 only shows the parts provided on the respective end flanges 51 and 53 of the conduit connecting unit 59, namely the guide pins 55 and 57 respectively, it is possible for such conduit connections which are inclined relative to each other to be connected together. This conduit connecting unit 59 also carries, at its center of gravity, a carrying lug 61 which can be engaged by a load hook. The guide pins 55 and 57 respectively are provided on their surface with barb-like notches 63 which, when the flange pairs are in the condition of being threadably disengaged from each other, effectively prevent the conduit connecting unit 59 from falling out because the notches 63 hook onto the upper edge of the respective catch ring at the end of the guide cradle. Dismantling of the conduit connecting unit 15 (FIGS. 1 to 3) takes place in the fashion described below. Using a lifting device, the operator brings a remotely controllable impact wrench to the end flange side of the conduit connecting unit 15 of one of the two pairs of flanges (11, 19). The three threaded bolts 23 are threadably disengaged and entirely removed from the threaded bores in the end flange 11, The pins or bolts 23 remain secured in position in the through bores in the end flange 19. The operator then moves the impact wrench to the other pair of flanges (13, 21) and there repeats the above-described operation. Although the threaded fastener connections between the conduit connecting unit 15 and the fixed flanges 11 and 13 are now disengaged, the conduit connecting unit is secured against dropping down by virtue of the guide pins 29 and 31 which are still in the inserted condition. The operator moves the impact wrench to a storage position by means of the lifting device and now uses the same lifting device for engaging the conduit connecting unit 15 at its carrier lug 27. The guide pins 29 and 31 come out of the catch rings by movement away from the fixed flanges 11 and 13 and the conduit connecting unit 15 can now be removed. A new conduit connecting unit 15 is brought up to the point of connection by picking it up at its carrying lug 27 by means of a lifting device which has a load hook. The operator places the conduit connecting unit 15 with the guide pins 29 and 31 substantially centrally on the periphery of the end flanges 11 and 13 and, by lowering the conduit connecting unit 15, permits the guide pins 29 and 31 to slide down on the outside periphery of the flanges so that the guide pins positively engage into the guide cradles. After that, a forward movement is performed in the direction towards the end flanges 11 and 13 by means of the lifting device, so that the guide pins 29 and 31 pass into the respective catch rings 35 and are secured therein. The crane hook of the lifting device is removed from the lug 27 and the lifting device is used to pick up an impact wrench and move it to the end flange side of the conduit connecting unit 15 of a pair of flanges (11, 19). The threaded fasteners 23 are screwed into the end flange 11 and then the same operation is carried out on the other pair of flanges (13, 21). The conduit connecting unit 15 has been quickly and safely replaced. It is understood that the foregoing descripton is that of the preferred embodiments of the invention and that various changes and modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.