KR100219766B1 - Cantilever counterweight fuelling machine bridge - Google Patents

Abstract

The bridge arrangement for supporting the fuel supply for the reactor has one main tower supporting the bridge as a cantilever. Counterweights adjacent to the main tower carry counterweights whose weight is equal to the weight of the bridge plus the fuel supply. Using rollers to provide minimal friction for vertical movement, bridges are installed on the pylons and counterweights are installed on counterweights. On both towers, the vertical ball screw is respectively coupled to the nut's balanced nut. The gears are engaged with the two ball screws so that the bridge rises and the counterweight falls or vice versa. Bending forces change the position of the fuel supply along the bridge but the actual weight does not change. Therefore, the weight of the screw on the tower does not change as it does on one of the pairs of supporting columns. Due to the counterweight, much less power is needed to raise the bridge.

Description

Bridge device for fuel supply

1 is an isometric view of the prior art of a bridge arrangement for supporting a fuel supply for a reactor.

2 is an isometric view of a bridge arrangement according to the invention.

3 is a partial cross-sectional front view of a pylon portion having a bridge portion.

4 is a side cross-sectional view of the pylon and counterweight tower.

5 is a plan view of the pylon and counterweight tower.

* Explanation of symbols for main parts of the drawings

14 fuel supply 20 pylon or frame

21: second tower or frame 22: balancing weight tower or frame

23: bridge 24, 25: brace member

26, 55: vertical member 27, 28, 30, 31: flange

35, 36, 53: extension member

37, 38, 46, 47, 57, 58, 65, 66: upper guide roller

44, 68, 70, 72: gear wheel

56: Counterweight

The present invention relates to a fuel supply bridge for a nuclear reactor, and more particularly to a counterweight cantilever configuration of a fuel supply bridge device.

Reactors with horizontally arranged fuel channels have a fuel supply at each end. When the fuel is supplied, the fuel supply is connected to each end of the predetermined fuel channel. The fuel bundle is compensated from one end and the replacement fuel bundle is inserted or filled at the other end. The fuel resupply requires accurate positioning of the fuel supply so that the suction of the fuel supply makes a satisfactory sealing engagement with the end fitting of the given fuel channel.

The fuel supply (used for fuel supply and release operations) is generally the same. The fuel supply is supported by the bridge. Thus there is a bridge arrangement with a pair of spaced towers at each end of the reactor and a horizontally extending bridge supported by the towers. The bridge is a heavy construction and supports a heavy reactor fuel supply. The bridge is raised or lowered to position the fuel supply vertically. Each tower has a fixed lead screw (or a pair of fixed lead screws) with a nut (suitably recirculating ball nut) supporting each end of the bridge. The screw is driven, i.e. rotated to raise or lower both ends of the bridge from the common drive means to maintain the same bridge level. The fuel feeder is installed on a bridge having transverse drive means for moving the feeder horizontally along the bridge. The fuel supply is therefore positioned by the transverse drive means laterally along the bridge and vertically by raising or lowering the bridge.

The bridge must not be inclined so that the fuel supply is correctly positioned. Because of the relatively heavy weight of the bridge and fuel feeder, it is difficult to have screws at both ends to raise or lower the bridge precisely with the fuel feeder at various locations. Canadian Patent No. 1,218,770, issued March 3, 1987 to Scott, relates to a system for detecting tilt in a bridge arrangement.

In addition, because the bridge having a fuel supply frame is heavy, the bridge tends to slowly rise and descend rapidly. In practice, the bridge does not require power when descending. Therefore, the vertical adjustment of the bridge position is different when the bridge rises and falls.

Summary of the Invention

The present invention utilizes a bridge arrangement or beam arrangement with a pylon or frame for supporting a spaced second tower and a pontoon-shaped bridge that guides the unsupported end of the bridge and prevents lateral movement. The third tower or frame is adjacent to the main tower. Supported by the third tower is the same counterweight in weight as the bridge and fuel supply. There are fixed lead ball screws in the main tower and the third tower. The screw has the same hand and the same lead. The gear device drives the screw from the common drive to the opposite rotation. The first bull nut is fixed to the bridge and screwed in the pylon. The second ball nut is secured to the counterweight and screwed to the third tower. Therefore, when the screw is driven to raise the bridge, the counterweight is lowered and raised.

When the weight of the bridge and the fuel supply are approximately equal to the weight of the counterweight, the power required to raise the bridge is significantly reduced. Much smaller electric motors are needed. Not only is the power saving significantly due to the small motor, but the load applied to the end fitting is also reduced if the fuel supply is coupled to the fuel channel end fitting while the bridge drive is accidentally pressurized.

Another advantage lies in the use of counterweight cantilever bridge arrangements with small vertical drive motors. Conventional bridges require large drive motors and small drive motors to raise the bridge and make small vertical adjustments in position. Smaller inertia speed controlled drive motors are used for main vertical drive because smaller motors are needed for counterweight bridges, which eliminates the need for additional small drive motors.

In addition, counterweight bridges or beams driven from one side have no inclination. The vertical load is always the same despite the position of the fuel supply. Attention is drawn to the support structure as the bending force can be changed with the fuel feeder at other locations.

Also, because there is a small force on the gear when the balance weight is present, the adjustment of the vertical bridge position tends to be reduced differently when the bridge is raised and lowered.

It is therefore an object of the present invention to provide an improved fuel supply bridge arrangement having a pylon or frame supporting a counterweight bridge positioned vertically by the drive means in the pylon.

Another object of the present invention is to provide a counterweight cantilever bridge device for supporting a fuel supply for a reactor.

Another object of the present invention is to provide a bridge device for supporting a fuel supply frame for a reactor in which the bridge has a tendency to be reduced with respect to the inclination.

Another object of the present invention is to provide bridge devices for supporting a fuel supply for a reactor that requires only one motor for vertical drive for the bridge rather than a large motor and a small motor for fine tuning.

Thus, a first vertical extension tower having a first vertical extension screw installed for rotation, and a bridge supporting the transversely operated fuel charger and supported at one end by the first tower as a cantilever for vertical movement on the first tower. A vertical extension installed for rotation with a first nut on one end of the bridge in engagement with the first screw by rotation of the first screw in the first direction to raise the bridging bridge and rotation in the second direction to lower the bridges; A second vertical extension tower adjacent the first tower having a second screw, counterweight means equal to the weight of the fuel supply frame installed in the second tower for vertical movement on the bridge and the tower, and a second screw in the second direction. Rotation is raised and rotation in the first direction engages the second nut on the counterweight means in engagement with the second screw and in the first and second directions by lowering the counterweight means. It provides a bridge device for supporting the fuel supply for the reactor, including drive means for coupling the first and second screw for rotating the screw amount.

The invention will be explained with reference to the accompanying drawings.

1 shows a conventional bridge arrangement having a pair of towers 10, 11. Bridge 12 extends between towers 10 and 11 and supports fuel supply 14. The fixed lead screw or ball screw 15, 16 extends vertically in each tower 10, 11. A nut or ball nut (not shown) on each end of the bridge 12 is associated with each screw 15, 16 such that the rotation of the screws 15, 16 can raise and lower the bridges integrally. The gear wheels 17, 18 fixed to the lower ends of the screws 15, 16 are engaged by the drive means (not shown) to rotate the screws 15, 16. Other drive means (not shown) drive the fuel supply 14 along the bridge 12 to a front and rear life so that the fuel supply 14 is correctly positioned. A bridge arrangement of this type is shown in the above mentioned Canadian patent 1,218,770. It should be noted that the load on the screw 15 when the fuel supply 14 is adjacent to the tower 10 is different than when the fuel supply is adjacent to the tower 11.

The bridge arrangement according to the invention of FIG. 2 has a main tower or frame 20 and a second tower or frame 21. Adjacent to tower 20 is counterweight tower or frame 22. The beam 23 or bridge is a cantilever bridge having brace members 24 and 25 extending from the point adjacent the unsupported end of the bridge 23 to the top of the vertical member 26. The brace members 24, 25, the vertical member 26 and the bridge 23 form rigid triangular structures. The end of the bridge 23, ie the unsupported end of the bridge 23, spaced apart from the vertical member 26 is a guide member coupled to the side of the tower 21 to prevent lateral movement of the unsupported end of the bridge. 48). The fuel supply 14 is installed on the bridge for lateral movement or horizontal movement following the bridge 23.

All towers 20, 21, 22 have a U-shaped cross section. The towers 20, 22 have bent flanges 27, 28, 30, 31. The flanges 27, 28, 30, 31 act as guides as will be apparent below. There are fixed lead ball screws 32 extending vertically in the tower 20 and similar screws 33 extending vertically in the tower 22. The screw has the same hand and leadron. The use of ball screws and nuts keeps frictional forces to a minimum.

In FIGS. 3, 4 and 5 the screw 32 extends vertically in the tower 20. The ball nut 34 is fixed to the extension members 35 and 36. The extension members 35 and 36 are fixed to the vertical member 26 having a U-shaped cross section. The extension members 35, 36 are coupled into the strip 20 between the flanges 27, 28. The pair of upper guide rollers 37, 38 are installed on the extension member 35 and are coupled to opposite sides of the flange 27. Similarly, the pair of lower guide rollers 40, 41 are installed on the extension member 35 and are coupled to opposite sides of the flange 27. In addition, the upper and lower guide rollers 42 and 43 are mounted on the extension member 35 and are supported on the inner surface of the tower 20 to prevent lateral movement. If necessary, the roller is positioned to be supported by the edge of the flange. Of course, there may be additional rollers if the associated forces are required. There are a pair of upper guide rollers 46 and 47 and a pair of lower guide rollers as shown in the extension member 36 and only the rollers 48 are shown in the figures, which are supported on opposite sides of the flange 28. The guide rollers 50, 51 are supported on the inner side of the tower 20 to prevent lateral movement.

Attached to the screw 32 and adjacent to the lower end are the gear wheel 44 and the drive input 45. When the drive input 45 causes the screw 32 to rotate, the bridge 23 and the fuel supply 14 will be raised and lowered in the direction of rotation.

In the tower 22, the screw 33 is similarly engaged with the nut 52 fixed to the two extension members 53, 54 fixed to the vertical member 55. The members 53, 54, 55 have a U-shaped cross section with an elongate member projecting inwardly from the vertical member 55 between the flanges 30, 31. The counterweight 56 is installed on the vertical member 55. The counterweight is equal to the weight of the bridge 23 and the fuel supply 14. An alternative design may place a counterweight on the centerline of the ball screw.

A pair of upper guide tollers 57 and 58 and a pair of lower guide rollers (only the guide roller 60 is shown in the figure) are installed in the extension member 53 and are supported by the flange 30. The guide rollers 61 and 62 are installed on the extension member 53 and are supported on the side inner surface of the tower 22 as shown. Similarly, the guide rollers 63 and 64 are installed on the extension member 54 and are supported on the inner surface of the side of the tower 22 as shown. A pair of upper guide rollers 65 and 66 and a pair of lower guide rollers (only the guide roller 67 is shown in the figure) are provided in the extension member 54.

Installed at the lower end of the screw 33 is a gear wheel 68.

There is an opening 72 extending through adjacent walls of the towers 20, 22 opposite the gear wheels 44, 68. Two additional gear wheels 70, 71 are coupled to gear wheels 68, 44 to form a gear train. When the drive input 45 rotates the gear wheel 44 with the screw 32, the gear wheel 44 rotates the gear wheel 71, 70, 68 with the screw 33. The gear hill work causes the screw 33 to rotate at the same speed in the opposite direction to the screw 32. Therefore, the counterweight 56 is raised and lowered when the bridge 23 is raised and lowered.

The drive input is much reduced compared to a bridge without balancing, so you will recognize that you need a much smaller drive motor. Also, regardless of the position of the fuel supply, the vertical load does not change, only the bending force changes.

It is clear that the use of counterweights of conventional construction with two support towers is not satisfactory. Assuming that there is a bridge arrangement with first and second support towers and adjacent counterweight towers of the first and second towers having counterweights, they are equal to half the weight of the bridge and fuel feeder. When the fuel supply is adjacent to the first tower, the load on the drive in the first tower is much larger than the load on the drive in the second tower and is inclined.

Claims (7)

A bridge arrangement for a fuel supply for a nuclear reactor, comprising: a vertically extending first tower having a first guide means, and transversely movable along the bridge, one end of the bridge being coupled to the first guide means; A cantilever bridge for supporting the fuel feeder supported by the first tower for vertical movement vertically; A vertically extending second tower adjacent the first tower and having a second guide means; Counterweight means coupled to the second guide means and supported by the second tower for vertical vertical movement of the second tower and equal to the weight of the bridge and the fuel feeder; A bridge device for interconnecting fuel with the bridge and the counterweight means for raising the bridge while the counterweight means is lowered and for lowering the bridge while the counterweight means is raised. . And a vertically extending third tower having guide means for engaging at an end of said bridge spaced from said one end to prevent lateral movement from said first tower. . A first vertically extending tower having a first vertically extending ball screw installed for rotation; A bridge supported by a transversely actuated fuel feeder and supported at one end by the first tower as a pincer for vertical movement on the first tower, A first nut on one end of the bridge that engages the first screw by rotation of the first screw in a first direction to raise the bridge and rotation in a second direction to lower the bridge; A counterweight means equal to the weight of a second vertical extension tower adjacent to the first tower having a vertically extending second ball screw installed for rotation, and a fuel feeder installed in the second tower for vertical movement with the bridge; A second nut on the counterweight means engaged with the second screw by rotating the second screw in a second direction and rotating in the first direction by lowering the counterweight means; And drive means for engaging the first and second screws to rotate both screws in the same direction in the first and second directions. A vertically extending third tower having a vertical extension guide means slidably engaged with the end of the bridge spaced from the one end to prevent lateral movement of the bridge as it is raised and lowered from the first tower; And a fuel supply bridge device, characterized in that it is provided. The bridge includes a vertical member that extends at an upper end at the one end adjacent to the first tower, a brace extending from an upper end of the vertical member to a point on the bridge spaced apart from the one end; And means by a roll on said vertical member that is rolled into said first tower to promote downward ear canal. The driving means may be configured such that the second screw is rotated in the one direction due to the rotation of the first screw in the one direction due to the rotation of the first screw in one rotation direction, so that the first and second And a gear means coupled with a screw. The first tower has a U-shaped cross section having a curved flange having an inner surface and an outer surface on an open side forming a guide means, wherein the vertical member extends adjacent to the outer surface of the flange and is rotatable on the vertical member. And the rollers are installed on the inner and outer surfaces of both sides of the flange.