RU2525191C1 - Gripping device - Google Patents

Abstract

FIELD: physics, atomic power.

SUBSTANCE: invention relates to nuclear power engineering and can be used primarily for rehandling spent fuel assemblies in heavy liquid metal coolant nuclear reactors. The gripping device has a housing made with a control mechanism in form of a control cam with cam slots, and a core with rods for opening the device, gripping elements made in form of rotating bars at the respective ends of which there are blocks for clamping the head of a spent fuel assembly, a flange for supporting a housing flange and rollers on axles capable of moving on the cam slots. In the lower part of the grooves there is a trapping unit which limits the bending of the rotating bars upon "destruction". The gripping device has a centre channel for passage of the device through the cover of the control and protection system.

EFFECT: overcoming the considerable buoyant force when immersing the gripping device into a coolant, reduced volume of immersed elements, removing control mechanisms of the device from the coolant area, monitoring the state (closed or open) of the device, preventing gripping elements from turning about their own axis and high reliability of operation.

9 cl, 9 dwg

Description

The invention relates to the field of nuclear energy and can be used primarily for overloading spent fuel assemblies (SFA) in nuclear reactors with a heavy liquid metal coolant.

When SFA is overloaded in a nuclear reactor with a heavy liquid metal coolant, it is necessary to carry out technological operations to engage the capture head ("fungus"), remove ("detonate") the SFA from its place, and lift the SFA into the transfer container, taking into account the conditions of nuclear and radiation safety.

The peculiarity of this overload process seems to be that the SFA is located under a layer of heavy liquid metal coolant; when the gripper is immersed in the specified coolant, it is necessary to overcome a significant buoyancy force due to the high density of the coolant exceeding the density of the material (steel) from which the gripper is made.

In addition, the mechanisms of the gripping device must remain operational when exposed to high temperatures of a heavy liquid metal coolant.

Due to the fact that the covers of the control and protection system (CPS) can be structurally above the SFA to a considerable height, it is necessary to ensure the possibility of unhindered passage of the gripper through and between the covers of the CPS, which in turn reduces the overall dimensions of the gripper.

Known automatic capture for goods with a figured head (patent RU, No. 1625808, B66C 1/66, publ. 02/07/1991), comprising a housing, articulated levers, articulated in its lower part, a rod and a slider connected to a copier.

The disadvantage of this gripping device is that it does not allow to pass through the CPS covers, overcoming the buoyancy when immersed in the coolant and work when exposed to high temperatures under the coolant layer

There is a gripping device for goods with a figured head (patent RU, No. 2034770, B66C 1/66, publ. 05/10/1995), containing gripping balls located in the radial holes of the guide, and equipped with locking balls located in the holes of the housing and interacting with extra sleeve.

A disadvantage of the known gripping device is that it does not allow it to pass through the CPS covers, to operate at high temperatures of a heavy liquid metal coolant and, in addition, to exclude damage to the load-gripping elements of the gripping device (guide) and the SFA head ("fungus") under "undermining" last one. Also, these devices do not allow you to monitor the state (closed or open) of the gripper, as they work in automatic mode, which can lead to an emergency when the SFA is overloaded.

The problem solved by the invention is the development of a device for performing technological operations for overloading SFAs in nuclear reactors with a heavy liquid metal coolant, which overcomes a significant buoyancy force when a gripper is immersed in a coolant with a minimum total weight and volume of immersed elements, with the removal of control mechanisms of the gripper from a zone of heavy metal coolant, with monitoring of the state (closed or open) of the gripping about a device that ensures the passage of the gripper through the CPS covers and the operability of the gripper mechanisms when exposed to high coolant temperatures.

When using the alleged invention are possible, in particular, the following technical results:

- providing overcoming significant buoyancy when immersing the gripper in the coolant;

- reduction in the volume of immersed elements;

- ensuring the operability of the mechanisms of the gripping device when exposed to high temperatures of the coolant;

- removal of the control mechanisms of the gripping device from the zone of heavy liquid metal coolant;

- tracking the status (closed or open) of the gripper;

- preventing the gripping elements from turning around their own axis;

- expansion of technological capabilities;

- increased reliability.

This problem is solved in that the gripping device comprises a housing, gripping elements, a control mechanism, lifting elements and a flange according to the invention

the housing is made with a control mechanism in the form of a control cam with curly grooves, with a core and rods to open the gripper,

the gripping elements are made in the form of rotary rods, at their respective ends there are crackers for “grasping” the heads of the spent fuel assemblies, a flange for abutting against the housing flange and rollers on the axes with the possibility of moving along the figured grooves, a trapping unit is installed at the bottom of them to limit bending pivoting rods with "blasting",

wherein the gripping device is made with a central channel for passing the gripping device through the covers of the control and protection system.

It is advisable to make the swing rods a length that allows the coolant layer to pass to the head ("fungus") of the spent fuel assemblies.

Preferably, the capture unit is made with holes for installing rods and a hole with a trap

It is desirable to perform the capture unit with friction bearings to rotate the rods around its axis.

It is advisable to position the control cam outside the zone of the heavy liquid metal coolant.

It is advisable to perform the grooves of the control cam along a helical line.

It is advisable to perform the grooves of the control cam in pairs towards each other

It is advisable to place the rollers outside the zone of a heavy liquid metal coolant.

Preferably, the core is provided with rods for opening the gripper.

It is advisable to provide the casing with a protrusion for performing "undermining" of the spent fuel assemblies.

The technical result is achieved by the fact that the gripping device is made with a massive body, which allows it to overcome significant buoyancy when immersed in a heavy liquid metal coolant. In addition, the massive casing ensures the exclusion of damage to the control mechanisms when working near a coolant having high temperatures.

Rotary rods are made in length, allowing the coolant layer to pass through the SFA head (“fungus”), and with crackers in their lower part for “wrapping” the SFA head (“fungus”) SFA, which ensures the minimum volume immersed in a heavy liquid metal coolant.

In the lower part of the rotary rods, a catching unit is installed, made with holes for installing the rods with friction bearings and a hole with a trap, which provides support for the rods and limits the opening (bending) of the latter when undermining the SFA.

The core, installed with the ability to move in the control cam, is equipped with a central channel for passing the gripper through the covers of the CPS, which ensures the expansion of technological capabilities.

The rollers mounted on the rods, mounted on the axles and interacting with the grooves of the control cam, and the control cam are removed from the zone of the heavy liquid metal coolant, ensuring the operability of the gripping mechanism.

Tracking the state (closed or open) of the gripper when working in a heavy liquid metal coolant is provided by moving the rod relative to the housing of the gripper.

Slots of the control cam, made curly, in a helical line and towards each other in pairs, provide for the rotation of the rods and the insertion of crackers of the rotary rods under the head ("fungus") of the SFA, and the direct groove of the control cam due to the locking with the key prevents the rotation of the rotary rods around their own axis.

The invention, in the particular case of implementation, is illustrated by the following drawings, presented in figures 1-9:

figure 1 - General view of the gripping device;

figure 2 - gripper - top view (figure 1);

figure 3 - the gripper is open - section BB (figure 1);

figure 4 - the gripping device is open - section aa (figure 3);

figure 5 - the gripper is closed - section bB (figure 1);

Fig.6 - the gripper is closed - section aa (Fig.5);

Fig.7 - elements of the gripper - view G (Fig.1);

Fig.8 - the gripper is open - section bb (Fig.3);

Fig.9 - node capture.

The gripping device (figure 1) contains a housing 1, made massive with the ability to overcome significant buoyancy force of the coolant and perform work at high temperature. The housing 1 (Fig.2, 3) is made with load-lifting elements 2 in the form of symmetrical blocks for connection to the load-lifting rope of the reloading container and a flange 4 located in its lower part. The gripping device is equipped with a control cam 3, moving inside the housing 1 with a restriction at the bottom of the flange 4.

The flange 4 (figure 3), placed in the housing 1, is made, in particular, with four holes for the installation of the respective rods 5 with the possibility of rotation around its own axis of the latter.

The gripping device is equipped with gripping elements in the form of rotary rods 5 with the possibility of rotation around its axis. The rotary rods 5 (Figs. 3, 4, 5), in particular four, are installed with the possibility of placement in the corresponding holes in the flange 4, are made long, that is, with a length that allows the coolant layer to pass to the head of the SFA, and with breadcrumbs 17 in their lower part for "girth" of the head ("fungus") of the SFA. The rotary rods 5 are made with a flange 18 and with the possibility of rotary rods to rely on them on the flange 4.

The control cam 3 (Fig. 3, 7) is equipped with slots, in particular four, with grooves 15 made curly along a helix and arranged in pairs towards each other (Fig. 8) to rotate the rods and establish crackers of the rotary rods under the head ( "Fungus") SFA, as well as a groove made straight, to fix the key 9 from turning around its own axis. At the same time, the control cam 3 is located outside the zone of the heavy liquid metal coolant, ensuring the operability of the gripping mechanisms when exposed to high temperatures.

The core 8 (figure 3), mounted in the control cam with the ability to move relative to the control cam 3, is provided with a central channel 10 for passing the gripper through the CPS covers, expanding technological capabilities, and rods 11 (figure 2, 3) for connecting control ropes to open the gripper. A spring 12 is installed on the core 8 (Fig. 3) to compensate for the pulling of the ropes attached to the lifting elements 2 and the rods 11.

On the rotary rods 5 mounted rollers 13 (Fig.4, 6) mounted on the axes and interacting with the grooves 15 curly control cam 3 (Fig.7). In this case, the rollers 13 are located outside the zone of a heavy liquid metal coolant, ensuring the operability of the gripping mechanisms when exposed to high temperatures of the coolant. In the lower part of the rods 5, a catching unit 6 is installed (Fig. 3) with friction bearings 7, allowing the rotary rods 5 to rotate around its axis. Moreover, the design of the rotary rods 5 can reduce the volume of immersed elements of the gripping device.

The capture unit 6 (Fig.3, 9) is made with holes for installing the corresponding rotary rods 5 with friction bearings 7 and a hole with a trap 14 (Fig.5), which rests the head ("fungus") of the SFA when docking the gripper. The capture unit 6 by combining the rotary rods 5 with friction supports 7 allows you to limit the opening (bending) of the rotary rods and to prevent damage to the elements of the gripper when undermining the SFA.

The operation of the gripper is as follows.

In the initial position, the gripper is suspended on a cable (not shown) of the winch of the transfer container (figure 2). In this case, the rollers 13 are located in the lower part of the grooves 15 of the curly control cam 3, and the crackers 17 of the rods 5 are turned outward (from the center to the periphery), the core 8 is raised and the spring 12 is in a compressed state.

Using a pointing device (not shown), the gripping device is guided to the SFA coordinate to be extracted, after which the winch of the container lowers the gripping device behind the load-lifting elements 2.

Next, the corresponding CPS cover enters the central channel 10 of the gripper. Lowering of the gripping device is carried out until the lifting ropes are loosened.

In this case, the trap 14 of the capture unit 6 abuts against the head ("fungus") of the SFA, restricting the downward movement of the housing 1 associated with the rods 5. The housing 1 of the gripping device provides it with the ability to overcome the significant buoyancy force of the heat transfer medium and the operation of the rods 5 under the heat-carrier layer , expanding technological capabilities and increasing reliability.

When you release the control cable (not shown) attached to the rods 11, the control cam 3 under the action of its own weight moves down and allows you to track the corresponding state (closed or open) of the gripper. The rollers 13, inserted into the grooves 15 of the curly control cam 3, rotate the rotary rods 5 around their own axes, thus making crackers 17 of the rotary rods 5 under the head (“fungus”) of the SFA in pairs towards each other. Now the gripper is in the closed position (figure 3).

To carry out the "undermining" of the SFA, the pipe of the pointing device behind the protrusion 16 (Fig. 1) of the gripping device lifts the SFA with a controlled effort to a fixed height. The friction bearings 7 of the rods 5 integrated in the collecting unit 6 do not allow the rods to disperse (bend) from the forces arising from this, excluding damage to the elements of the gripping device.

When lifting the gripping device for lifting elements 2, the housing 1 with the control cam 3 moves up into the reloading container.

The opening of the gripper takes place in the reverse order.

Claims (9)

1. The gripping device comprising a housing, gripping elements, a control mechanism, lifting elements and a flange, characterized in that the housing is made with a control mechanism in the form of a control cam with curly grooves, with a core and rods for opening the gripping device, the gripping elements are made in the form rotary rods, at their respective ends there are crackers for “grasping” the heads of the spent fuel assemblies, a flange for abutting against the housing flange and rollers on the axles with the possibility of moving along the grooves of FIG First, a trapping unit is installed in their lower part, which limits the bending of the slewing rods during “undermining”, while the gripping device is made with a central channel for passing the gripping device through the covers of the control and protection system. 2. The gripping device according to claim 1, characterized in that the rods are made in length, allowing the coolant layer to pass to the head ("fungus") of the spent fuel assemblies. 3. The gripping device according to claim 1, characterized in that the capture unit is made with friction bearings for rotating the rods around its axis. 4. The gripping device according to claim 1, characterized in that the capture unit is made with holes for the installation of rods and a hole with a trap. 5. The gripping device according to claim 1, characterized in that the control cam and rollers are located outside the zone of the heavy liquid metal coolant. 6. The gripping device according to claim 1, characterized in that the grooves of the control cam are made along a helical line. 7. The gripping device according to claim 1, characterized in that the slots of the control cam are made in pairs towards each other. 8. The gripping device according to claim 1, characterized in that the core is provided with rods for opening the gripping device. 9. The gripping device according to claim 1, characterized in that the housing is provided with a protrusion for performing "undermining" of spent fuel assemblies.

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