Abstract
A sleeve made of rigid tube into which the feed lines for feeding the waste to treated and the gases to be discharged lead. In order to avoid contamination or blockage of the sleeve, a tool for scraping the inner face of the wall thereof is added, in this case a terminal tubular section of one of the feed lines, which carries out orbital movements tangent to this inner face. Various cooling, rinsing and overpressure structures are added, as is a docking device extending at the bottom of the sleeve for connecting the latter to the heat treatment container.
Claims
1. Device for feeding a container for an installation for the heat treatment and conditioning of waste, comprising a sleeve having a lower opening to be docked with an upper opening of the container, a first line for feeding the waste to be treated connecting to the sleeve and penetrating therein, the sleeve containing a tool for scraping its inner face, wherein the scraping tool is a sheath of axis parallel to the sleeve and forming a terminal section of the first feed line, and the device comprises a support of the sheath, the support being provided with a motorised off-centring mechanism to which the sheath is suspended, the off-centring mechanism moving the sheath in orbits where it is adjacent to the inner face of the sleeve.
2. Device for feeding a container according to claim 1, wherein the sheath extends beyond the sleeve in a direction opposite the lower opening, through a sealing plate at the upper end of the sleeve, the sealing plate comprising a movable plate linked to the sheath, and a fixed plate linked to the sleeve and on which the movable plate moves, the fixed plate being provided with an opening for passage of the sheath that is larger than the latter, and a sealing device between the fixed plate at the movable plate.
3. Device for feeding a container according to claim 1, wherein the off-centring mechanism comprises a toothed gear wheel to which the sheath is suspended, without being coaxial to an axis of rotation of said toothed wheel.
4. Device for feeding a container according to claim 1, wherein the off-centring mechanism is arranged to also make the sheath rotate about itself.
5. Device for feeding a container according to claim 3, wherein the off-centring mechanism comprises a gear between a toothed wheel attached to the sheath and a toothed ring attached to the off-centring mechanism, and the sheath is rotatably mounted in the toothed gear wheel to which it is suspended.
6. Device for feeding a container according to claim 4, wherein the sheath has a helical excrescence, particularly a helical blade, on its outer face.
7. Device for feeding a container according to claim 1, wherein the first feed line contains at least one rotating swirler, particularly of the pigtail type, to advance the waste to be treated.
8. Device for feeding a container according to claim 2, wherein the swirler extends beyond the sheath in the direction opposite the lower opening of the sleeve, is suspended to a second motorised off-centring mechanism to which the sheath is suspended, and is rotated by a motor mounted on the second off-centring mechanism.
9. Device for feeding a container according to claim 8, wherein the off-centring mechanism to which the sheath is suspended and the second off-centring mechanism are mechanically connected to one another and driven by the same motor.
10. Device for feeding a container according to claim 2, wherein the first feed line comprises an upstream section, forming an angle with the terminal section and connected to the terminal section by an overflow unit, the terminal section being provided with a funnel at its top, which is connected to a pierced lower face of the overflow unit, the sheath being movable under the overflow unit.
11. Device for feeding a container according to claim 10, wherein the sheath is sliding in an axial direction of the sleeve, and the upstream section is tilting by being hinged, at its two ends, to a fixed point of the device and to a wall of the overflow unit.
12. Device for feeding a container according to claim 10, wherein the upstream section is equipped with a motorised rotating swirler, and connected, at an end opposite the overflow unit, to a hopper for pouring the waste to be treated.
13. Device for feeding a container according to claim 1, wherein it comprises a second feed line made of material of a matrix for conditioning the waste, opening into the sleeve.
14. Device for feeding a container according to claim 13, wherein the sleeve consists of two portions in extension, that can be dismantled from one another and equipped with different coolant circuits, a lower portion of which comprising the lower opening, and an upper portion into which the second feed line and a line for discharging gaseous products from heat treatment open.
15. Device for feeding a container according to claim 1, wherein the second feed line is equipped with a scraper of its inner face.
16. Device for feeding a container according to claim 15, wherein the scraper is a ram sliding in a section of the second feed line adjacent to the sleeve, and housed in an extension of said section of the second feed line, beyond an upstream section of the second feed line forming an angle with said section adjacent to the sleeve.
17. Device for feeding a container according to claim 16, wherein a hole and a rinsing liquid pipe pass through the ram.
18. Device for feeding a container according to claim 1, wherein the sleeve comprises a main rigid tubular portion and a docking device, the docking device comprising a docking sleeve surrounding the main portion by extending downwards, comprising the lower opening of the sleeve, mounted on the main portion and movable along the main portion.
19. Device for feeding a container according to claim 18, wherein the docking sleeve comprises a compressible portion in the direction of the mobility of the docking sleeve.
20. Device for feeding a container according to claim 18, further comprising a means for rinsing an annular volume between the docking sleeve and the main portion of the sleeve.
21. Device for feeding a container according to claim 19, further comprising a means for rinsing an annular volume between the docking sleeve and the main portion of the sleeve, wherein the compressible portion is a bellows, and the rinsing means comprises inlet pipes in the annular volume that overhang the bellows, guided radially towards the main portion of the sleeve and producing bounces of rinsing liquid radially outwardly and towards the bellows.
22. Device for feeding a container according to claim 18, wherein it comprises a pipe for injecting overpressure gas into an annular volume between the docking sleeve and the main portion of the sleeve.
23. Device for feeding a container according to claim 18, wherein the docking sleeve comprises a docking sheath sliding on the main portion of the sleeve, and actuators for moving the docking sheath connecting the docking sheath to the main portion of the sleeve.
24. Device for feeding a container according to claim 23, wherein it comprises a pipe for injecting overpressure gas into an annular volume between the docking sheath and the main portion of the sleeve.
25. Device for feeding a container according to claim 1, further comprising a pressure intake pipe comprising rinsing means, extending in a wall of the sleeve along the sleeve, and opening at a lower edge of the sleeve.
26. Device for feeding a container according to claim 1, further comprising a means for measuring the filling level of the container, disposed through the sleeve with overpressure gas injection into the pipe.
Description
[0035] FIG. 1: a general view of a particular installation for the heat treatment, namely in can vitrification, that is to say directly in the canister intended for storage and disposal, wherein the feeding device according to the invention may be used;
[0036] FIG. 2: a general view of the feeding device in a non-docking state of the container (pigtail raised);
[0037] FIG. 3: another general view of the same, in the docking state of the container (pigtail engaged in the container);
[0038] FIG. 4: the isolated sheath;
[0039] FIG. 5: the top of the sheath, in section;
[0040] FIG. 6: the device for supporting and driving the sheath, in general representation;
[0041] FIG. 7: a detailed view, in section and perspective, of a portion of this device;
[0042] FIG. 8: certain gears of this device;
[0043] FIG. 9: the top of the sleeve, in section and perspective;
[0044] FIG. 10: the support and drive device, and the neighbouring portions of the device, in section;
[0045] FIG. 11: the configuration of the device and of the container in the non-docking state;
[0046] FIG. 12: the configuration, in the docking state;
[0047] FIG. 13: a partial view of the sheath in section;
[0048] FIG. 14: the second feed line, in the normal state;
[0049] FIG. 15: this line, during scraping;
[0050] FIG. 16: details of the docking device;
[0051] FIG. 17: other details of the docking device;
[0052] FIG. 18: an inspection device.
[0053] FIG. 1 shows a vitrification installation. Radioactive waste vitrification containers are called cans 1, and they are successively provided in a furnace 2 here consisting of two semi-cylindrical halves that can be move closer to one another in order to clamp a can 1. The cans 1 have a neck 3, equipped with an upper opening 4 delimited by a flat flange 5, at their top. In reality, these are crucibles that withstand the very high temperatures produced during the vitrification operations. The furnace 2 may be with heating of the resistive type. Its upper lid 6 (shared between the two halves) includes a central opening 7 under which the neck 3 of the can 1 is located clamped by the furnace 2 during a vitrification operation. A station for pre-loading the cans 1, unrelated to the invention, bears the reference 8.
[0054] Interest will now be paid to a feeding device 9 adjacent to the furnace 2; FIG. 1 illustrates that it particularly includes: a sleeve 10, which mainly comprises a vertical cylindrical tube open downwards and that extends, in the disjoint state of the device preceding vitrification, facing the neck 3 of the can 1 clamped more or less at a distance above it; on the left side of this FIG. 1, appear means 12 for treating the gases from the vitrification operations, according to features known by the person skilled in the art and that do not form part of this invention.
[0055] The detail of the feeding device 9 becomes more apparent in FIG. 2. It comprises a line 11 for feeding waste to be treated, consisting of a vertical sheath 16 containing a swirler 18 that rotates therein, which is in the form of a helix with coils that are close together and not very inclined (pigtail), of a hopper 14 from which the waste is extracted and of an oblique section 15 connected to the vertical sheath 16. Optionally as shown in FIG. 2, the oblique section 15 contains a swirler 17 that rotates therein, also of the pigtail type.
[0056] Thanks to these means, the content of the first feed line 11 is forced to advance and to go down before dropping into the opening 4 of the can 1 located below the sleeve 10. The oblique section 15 and the sheath 16 connect to one another by an overflow unit 19. A drive device 20 extends above the sleeve 10. The rigid main tube of the sleeve 10 consists of a lower portion 21 and of an upper portion 22 that extends the preceding upwards, and that is connected thereto by an assembly of bolted flanges 23.
[0057] A second feed line 24, intended to feed the can 1 with a glass frit that constitutes the material of the conditioning matrix to obtain the final vitrified product, opens into the upper portion 22, in the same way as a gas removal line 25, at an altitude a little higher. The second feed line 24 particularly comprises a vertical section 26, a downward oblique section 27 that connects the vertical section 26 to the sleeve 10, and an extension 28 of the downward oblique section 27 that extends, in relation thereto, on the side opposite the sleeve 10. The invention may be applied to devices devoid of such a second feed line, if all of the products to be treated are introduced via the same feed line.
[0058] The lower portion 21 of the sleeve 10 comprises on its outer face a docking device 29 on the collar 5 of the can 1, and to which the lower opening 109 of the sleeve 10 belongs; the cylindrical tube consisting of the lower portion 21 and of the upper portion 22 stops a little above the lower opening 109.
[0059] These various main elements of the invention will be described in turn in the following description.
[0060] FIG. 2 illustrates the feeding device 9 in a completely raised state, where it does not touch the collar 5. FIG. 3 shows it in the completely lowered state, characterised by an expansion of the docking device 29 downwards, which makes it reach the collar 5 with a compression force, and by a lowering of the sheath 16, which projects its lower end into the neck 3 of the can 1; the drive device 20 is also lowered, and the oblique section 15 is inclined downwards by approaching the sheath 16; for this it is hinged via a ball joint 30 to the overflow unit 19, and to a horizontal pivot 31 mounted at a fixed location of the feeding device 9, at its opposite end. The state in FIG. 2 corresponds to the phases for changing the can 1, that the feeding device 9 releases; and the state in FIG. 3 corresponds to the vitrification operation phases, where sealing is performed between the feeding device 9 and the can 1.
[0061] The sheath 16 is shown in FIGS. 4 and 5. It has a helix 32 on the outer face of its cylindrical wall, the coils of which are significantly inclined and far enough apart from one another. Its upper end has an inlet funnel 33 the upper face of which is a flat collar 34. The wall of the sheath 16 is double and cooled by fluid circulating in pipes 35 (shown in FIG. 5) forming an inner cooling cavity, and which open a little below the funnel 33 into a water box 36 that sealingly surrounds the portion of the sheath 16 located at this height. As the sheath 16 rotates about itself but the water box 36 is fixed in rotation, a permanent circulation of the coolant is maintained by providing the water box 36 with a water inlet chamber 37 and with a water outlet chamber 38 that are both circular but at different altitudes, and wherein the inlet 98 and outlet ends 99 of the pipes 35, at corresponding altitudes, constantly open. The sheath 16 is maintained by a first toothed eccentric 39 of horizontal axis while being rotatable about itself therein, and it extends downward by passing through a hole 40 of the first toothed eccentric 39. The sheath 16 finally has a toothed wheel 41 that extends around its outer face, and a crown 95 a little above the toothed wheel 41, with which it is concentric. If however, the toothed wheel 41 is attached in relation to the sheath 16, the crown 95 is connected thereto by a bearing 96 and may therefore rotate about itself. In addition, the crown has axes 97 of rotation of the toothed pinions 42 (shown in FIG. 8) that mesh with the toothed wheel 41. Bearings 100 are disposed between the first toothed eccentric 39 and the sheath 16 to ensure that the latter remains centred in the hole 40, and rotates without significant effort in relation to the first toothed eccentric 39.
[0062] The drive device 20 is now described by means of FIGS. 6 to 8. It comprises a support 44, supported by a pair of vertical cylinders 45 mounted on the upper portion 22 of the sleeve 10, and that may therefore raise the support 44 and the entire drive device 20 above the sleeve 10 (which is illustrated in this figure and corresponds to the raised state of the sheath 16 illustrated in FIG. 2), or lower the support 44 by placing it on the top 46 of the sleeve 10 (which corresponds to the lowered state of the sheath 16 illustrated in FIG. 3); small guide columns 47, vertical and attached under the support 44, maintain its horizontal position by sliding in holes of a collar 48 equipping the top 46.
[0063] The support 44 has a toothed crown 49, a first motor 50, and the overflow unit 19, which are attached thereto; it also has the first toothed eccentric 39 by means of a drive ring 101, and a second toothed eccentric 51, having the same features of dimension and or toothing as the first toothed eccentric 39, coaxial and parallel thereto, and provided with a shaft end 52 rotating in a cylindrical housing 102 established on a top face 53 of the overflow unit 19. The shaft end 52 is supported by a bottom face 103 of the cylindrical housing 102. The swirler 18 is suspended to the second toothed eccentric 51 and attached to it (shown in FIG. 10), and it extends through the overflow unit 19 by passing through a hole 54 of the top face 53, then it extends into the sheath 16. The second toothed eccentric 51 also has a second motor 55, which drives the swirler 18 in rotation by a gear 56 (FIG. 2). The first motor 50 drives the slewing ring 101, of vertical axis of rotation, and the first toothed eccentric 39. The latter 39 meshes with a first drive pinion 58 of vertical axis, and it also drives a second drive pinion 59 above the preceding, similar and joined to the latter by a vertical synchronisation shaft 60. With the exception of the worm 57, all of the pinions and other toothed mechanisms have axes of rotation parallel with one another and with the axes of the sleeve 10 and of the sheath 16, that is to say vertical. As the drive pinions 58 and 59 are identical and superposed, and the toothed eccentrics 39 and 51 are also identical and superposed, the rotations of the first motor 50 produce identical circular orbital movements for the sheath 16 and its swirler (pigtail) 18, which therefore moves them in unison in the sleeve 10, the swirler 18 remaining centred in the sheath 16. The orbit of the movements maintains the sheath 16 adjacent to the inner face of the sleeve 10, which scrapes it and removes the deposits of materials that foul it. In addition, the rotation of the toothed pinions 42, which mesh both with the toothed wheel 41 attached to the sheath 16 and with the toothed crown 49 (FIG. 8), imposes a rotation of the sheath 16 about itself jointly with the orbital movement, which increases the scraping thanks to the helix 32, which makes the deposits scraped along the sleeve 10 go down.
[0064] The orbital movement of the sheath 16 imposes certain measures to maintain the sealing. FIG. 9 illustrates that the sheath 16 is surrounded by an outer collar 61, which is retained in a horizontal rabbet 104 inside the collar 48 by being able to slide therein horizontally: it slides on a horizontal flat bearing surface 62 established around a central hole 105 of the collar 48, distinctly wider than the sheath 16, and it is covered by a hold-down plate 63 that retains it on the flat bearing surface 62 and delimits the rabbet 104 with the latter, by thus forming a sealing plate. Seals 64 are added between the outer collar 61, the flat bearing surface 62, the hold-down plate 63 and the sheath 16. In addition, FIG. 10 shows a similar layout under the overflow unit 19, with the flat collar 34 of the funnel 33 sliding in a flat and circular rabbet 65 established between two thicknesses of a bottom face 66 of the overflow unit 19, seals 67 also being placed between the flat collar 34 and the flat faces opposite the rabbet 65. Moreover, the bottom face 66 is attached to a support post structure 68 belonging to the support 44 and that makes it possible to raise the overflow unit 19 above the gears for setting in motion the sheath 16. FIG. 10 also shows numerous details of neighbouring parts of the device, particularly of the drive unit 20; it also shows circuits for cooling the main tube of the sleeve 10, which comprise water inlet and outlet pipes, 110 for the upper portion 22 and 111 for the lower portion 21, which open into cooling cavities, 112 for the upper portion 22 and 113 for the lower portion 21, consisting of double cooling shells; these cooling circuits are completely separate.
[0065] FIGS. 2, 3, 11 and 12 help to describe the docking device 29. It surrounds the lower portion 21 of the sleeve 10, and it is attached to it by a ring support 69. Screw jacks 70 are supported by the ring support 69, and they suspend a docking sleeve 71 sliding along the sleeve 10 in the direction of its axis. In the state in FIG. 2, the docking sleeve 71 is raised; in that of FIG. 12, corresponding to the lowered state in FIG. 3, it is lowered, a docking flange 72 that constitutes its lower end is joined to the top flange 5 of the can 1, and the flanges 5 and 72 may be held against one another by clamping a clamp 73 disposed around the docking flange 72. The sleeve 10 itself does not change altitude between these two states, but the docking sleeve 71 extends it downwards by a variable height. The docking sleeve 71 comprises an elastic portion 74 consisting of a bellows, which absorbs the compressions caused by the excessive lowering of the docking sleeve 71 beyond the contact with the top flange 5 of the can 1, and by the thermal expansions of the can 1 during the vitrification operations. The clamp 73 is supported by static tie rods 75 extending vertically along the elastic portion 74.
[0066] The following figures are now considered to discover other layouts combating the fouling of the portions of the feeding device 9. FIG. 13 shows that the sheath 16 contains a tube 76 that passes through it by extending over its entire height in its cooling cavity, from the water box 36 up to the lower edge 77, of the sheath 16 from where it can project rinsing water downwards. The device also comprises an end fitting 78 of the water box 36, and a circular feeding chamber 79, hollowed into the water box 36 at an altitude other than the preceding. It should be noted that this device is used, in the absence of rinsing, as a pressure intake inside the can 1, by connecting a measuring apparatus to the end fitting 78.
[0067] FIGS. 14 and 15 illustrate a device associated with the second feed line 24. The extension 28 contains a scraping ram 80, which consists of a piston at the end of the rod of a cylinder 81. The ram 80 remains in the extension 28 in the idle state, but it slides in the downward oblique section 27 when the rod of the cylinder 81 is deployed, by rubbing against its wall or at least by passing against it, which removes the dirt that fouls it. The ram 80 and the rod of the cylinder 81 are in addition cleared by a rinsing pipe 82, connectable to a pressurised water supply apparatus and used if necessary to rinse the downward oblique sections 24 and 27.
[0068] FIG. 16 indicates that the docking device 29 may be provided with tubes for injecting air 83 into a gap between the sheath 16 and a docking sheath 84 sliding thereon. The docking sheath 84 belongs to the docking sleeve 71, of which it forms an upper portion, and it guides its vertical sliding movement. The annular gap is closed by circular seals 85 located at its top and bottom ends. The overpressure that establishes in the gap impedes the entry of impurities deposited on the sheath 16 in this gap when the docking sheath 84 lowers, and therefore reduces the risks of blockage.
[0069] The bellows 74 is retained between an upper flange 86 and a lower flange 87, best shown in FIG. 17. The volume 106 that it encloses around the sleeve 10 must also favourably be guaranteed against dirt. An air injection tube 88 passes through the upper flange 86 to create an overpressure in this volume 106. Water injection holes 89 also pass through it, and water discharge holes 91 pass through the lower flange 87. The water injection holes 89 are distributed around the circumference of the upper flange 86, and they extend from water boxes 90 hollowed at the top of the upper flange 86 up to a conical clearing 107 located under the upper flange 86, while being guided downwards and radially inwards. The water discharge holes 91 also have a radial and vertically oblique orientation, and they go down from a bottom of the volume 106 to an interior of a funnel 108 that forms the bottom of the docking device 29, and that ends at the docking flange 72. The overpressure produced by the injection of air largely prevents the dirt carried upwards by the fumes from entering into the volume 106. In addition, the water injected radially inwardly bounces against the outer face of the sleeve 10 and coming out of the water injection holes 89, disperses in the conical clearing 107 then in the entire volume 106, before flowing into the funnel 108 either directly, or by following the water discharge holes 91.
[0070] The invention is also compatible with the taking of measurements during the operations of vitrification or of other treatments. A possibility of a pressure intake through the sheath 16 has already been encountered. Another possibility relates to viewing the content of the can 1 and for example its level. FIG. 18 shows a sight tube 92 that obliquely passes through the upper flange 86 and is guided into the gap between the bottom of the sleeve 10 and the docking sleeve 71; the sight passes through a local notch 93 of the sleeve 10; the viewing direction subsequently extends through the neck 3 and leads into the can 1. The measurement is carried out for example by a laser 114, by leaving the sight tube 92 closed by a transparent porthole 94, behind which the laser 114 is installed; its beam 115 is directed in the axis of the sight tube 92; the latter is flushed by an injection of overpressure gas, introduced by a pipe 116 that connects to the inside of the sight tube 92 below the transparent porthole 94, to keep it free of fumes.
[0071] The equipment for injecting and discharging the fluids, as well as the measuring means envisaged, are considered as known and therefore are not described in detail here.
