Patent Number: 047085711
Section: description

SPECIFIC DESCRIPTION In general, the apparatus shown in the drawing comprises a melting furnace 1 which may be of any conventional type and can be inductively heated and evacuated. For convenience, the evacuation is shown to be effected by a fitting 4 communicating with a hood 1a at the top of the furnace. The balance of the furnace has not been illustrated but it will be understood that this furnace can have a siphon transfer device including an inverted U tube of the type previously mentioned, one leg of which reaches into the melt within the furnace while the other leg of which reaches into a sealed ingot mold or receptacle which in turn is evacuated. At the mouth of the furnace defined by the hood 1a, a gate generally represented at 2 is provided. As can be seen from a comparison of FIGS. 1A and 1B this gate is formed by a container 5 which can be positioned over the mouth of the furnace in the alignment with and engagement with a seating ring 18, the mouth otherwise being closed by a slider represented at 13 which will be described in greater detail hereinafter. The device 3 for transferring the waste to the furnace 1 generally comprises a carriage mounted upon wheels 3a, 3b and having a framework 3c which carries a guide 10a forming part of a transfer unit generally represented at 10 laterally engaging the container 5 and enabling the container to be shifted from the position shown in FIG. 1A in which it receives the vessel to a position in which the container is inverted and discharges its contents, namely the vessel and the radioactive waste, into the furnace (FIG. 1B). The furnace charging container 5 has an upper container mouth in its initial position shown in FIG. 1A which can be closed by a laterally retractable cover 7 guided on a track 12a and displaced by a fluid operated cylinder arrangement 12 affixed to the container is suspended by a pair of laterally extending trunions 9 and a yoke 10b carrying the trunions in a pair of pivot carriages 8 which are guided by rollers 8a on the track 10a previously mentioned. The assembly 10a, 10b forms a guide unit 10 enabling the container to be shifted between its right hand position shown in FIG. 1A and its left hand position shown in FIG. 1B along the track 10a. The trunnions 9 define a horizontal pivot axis about which the container may be swung through 180.degree.. The charging carriage 3 can be therefore filled with the transport vessel represented in dot dash lines in FIG. 1A and 17 at any location and then brought into the region of the furnace with the container 5 inverted or the container 5 can be inverted and then the container moved toward the transport vessel with the carriage 3 in place. As previously mentioned, the mouth of the furnace is provided with a gate slider arrangement generally represented at 11 onto which the inverted mouth of the container 5 can be placed, the slider gate 13 of this mouth being displaceable independently of the retractable cover 7 by a slider retraction unit 14 which may also be a fluid operated unit. As can be seen from FIG. 2, the unit 14 lies at a right angle to the unit 12 which displaces the cover 7. In addition, the bottom 15 of the container 5 can be formed with a perforating unit 16 which has been illustrated in greater detail in FIG. 4. The unit 16 can comprise a fluid pressurizable cylinder 16a which has a piston 16b connected to a piercing tool 16c adapted to pierce the bottom 17c of the transport vessel 17 to leave a hole 17a therein of a diameter or cross section sufficient to vent the pressure build up in the container if the cover 17b is left sealingly attached thereto when that cover is introduced with that vessel into the container 5. As has been shown in greater detail in FIG. 5, when the container 5 is positioned on the seating ring 18 of the mouth of the furnace, the slider 13 and the cover 7 are normally in their closed position. In this embodiment, the cover 17b has been shown to have been loosened somewhat from the transport vessel 17. The waste is illustrated at 17d in this FIGURE. The cover 7 is then retracted in the direction of arrow A while the slider 13 is retracted in the direction of arrow B (FIG. 2) and the cover 17b, the waste 17d and even the container 17 can fall freely into the furnace 1. FIGS. 1A and 1B show two functional positions of the apparatus. FIG. 1A shows the charging container 5 in its position in which the transport vessel 17 can be inserted. After insertion of the transport vessel 17, the cover can be loosened or can be permitted to remain in place or even removed as previously mentioned. The transport vessel 17 is lowered into the container 5 by any conventional hoist provided in the foundry. The container is inserted in the direction of the arrow C shown in FIG. 1A. The cover 7 is thereupon closed by movement in the direction of arrow D in FIG. 1A thus via the cover displacing fluid operated unit 12. The charging container 5 more or less conforms in shape to the transport vessel 17. Thus with larger transport vessels, larger furnace charging containers 5 are used than is the case with smaller transport vessels 17. After the charging container 5 has been rotated through 180.degree. about its horizontal axis defined by the trunions 9, it is placed upon the seating ring 18 of the furnace and the cover 7 and the slider 13 are then retracted at right angles to one another in the manner described in connection with FIG. 5. The contents of the container 5 thereupon fall into the furnace and a gate slider 13 can be closed. The charging unit can be returned to its original position for receiving another container. The furnace is meanwhile evacuated and its contents melted in the usual manner.