RU2459763C1 - Screw elevator - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to nuclear power engineering and may be used in reactors with liquid-metal heat carriers for mounting and dismantling reactor cover protective plug. Screw elevator comprises framed structure with straight guides and three guide screws with gears to engage with common gear wheel. Drive unit with nut and moving top and bottom stops are fitted on every guide screw. Said stops comprises axles to fit in horizontal grooves made in drive unit and those in guides for drive unit to slide thereon. Grooves in guide top section are inclined to allow move top and bottom stops aside.

EFFECT: higher smoothness of protective plug displacement in reactor cover, automatic control over elevator.

5 dwg

Description

The invention relates to nuclear technology and is intended for use in reactors with a liquid metal coolant, namely, when installing or removing a sealing protective plug in the reactor lid.

A device for depressurizing and removing the reactor lid using a hydraulic lift (patent RU No. 2333148, B66F 3/24, B66F 7/20, B66F 11/00, publ. 09/10/2008). But in the case of removing the sealing protective plug of a reactor with a liquid metal coolant, when a significant buoyancy force acts on the plug, a hydraulic hoist cannot be used.

Known screw lifts, for example, according to patent No. RU 2271329 B66B 9/02, publ. 03/10/2006 or No. 2092426 B66F 3/08, B66F 7/14, publ. 10.10.1997, cannot be used in conditions of multidirectional efforts during lifting, and even more so when installing the plug in the reactor lid.

A feature of the process of vertical movement of the plug from the lid of a reactor with a liquid metal coolant by means of a screw hoist is the multidirectionality and change of forces acting on the tube due to the influence of the buoyancy force generated by the liquid metal coolant on it.

In addition, when the plug is lifted from the reactor lid, the radiation situation in the area of the screw elevator sharply worsens, and it is necessary to automatically disconnect the plug from the screw elevator for its subsequent removal into the protective suit.

The load-bearing elements of the screw hoist should ensure unimpeded movement of the plug during its installation and removal from the reactor lid.

The closest analogue of the design of a helical elevator for removing and installing plugs in the lid of a reactor with a liquid metal coolant is the device according to patent RU No. 2297568, F16K 3/18, F16K 31/54, publ. 2007, comprising a housing, a displacement drive, and lifting screws with gears gearing with one gear.

A disadvantage of the known device is the inability to use it to move objects with alternating load, as well as the inability to move objects inside the device.

The basis of the invention is the task of developing a helical elevator for installing and removing the protective plug in the reactor cover under multidirectional loads, capable of providing automatic coupling and disengagement with the protective plug.

In addition, the screw hoist should be located in a limited space above the reactor cover and provide the possibility of unimpeded movement of the plug inside the hoist to remove it in a protective suit.

The invention provides the following, in particular, technical results:

firstly, increased smoothness of the movement of the cork under conditions of alternating load;

secondly, the improvement of radiation conditions during operation due to automatic trip or clutch with the cork.

The invention consists in the following.

The screw elevator interacting with the movable plug contains a frame structure that serves as a power support for the drive, three lead screws and straight guides with grooves. On each of the lead screws there is a power unit with a nut and movable stops - upper and lower. The nut is used for the interaction of the power unit with the thread of the lead screw. The power unit moves along straight guides with grooves. The horizontal movement of the stops relative to the power unit is determined by the path of the grooves in the guides and the horizontal grooves in the power unit, which include the axis of the stops. The upper stop serves to limit the movement of the plug in the vertical direction relative to the power block, under the influence of the buoyancy force. The lower stop serves to prevent the cork from falling. Each of the spindles contains a gear that engages in gearing with one unifying gear. The unifying gear is rotated from a separate drive. The plug is connected to a traverse containing three protrusions, which are designed to interact with the movable stops of the power unit. These three protrusions are mounted on the traverse with the possibility of a turn relative to the vertical axis of the cork. The indicated spread of the protrusions is necessary for their joining with the stops of the power unit during installation of the screw hoist.

The invention is illustrated by drawings:

figure 1 is a longitudinal section of a helical elevator;

figure 2 is a section along aa;

figure 3 is a section along BB;

figure 4 is a section along BB;

5 is a view of G.

The helical elevator comprises a frame part 1 with straight guides 2 and three spindles 3 with gears 4, which are engaged in gearing with the unifying gear 5. In the upper part of the helical elevator is a drive 6, which is connected to the unifying gear 5 through the drive shaft 7 and gear 8 on the last. On each of the lead screws 3 there is a power block 9 with a nut 10 and movable stops upper 11 and lower - 12. The stops 11 and 12 contain axes 13 included in the horizontal grooves 14 located in the power block and grooves 15 of the guides 2, along which it moves power block. The grooves 15 have a vertical direction in the lower part and an inclined direction in the upper part. The stops 11 and 12 cover the protrusions 16 associated with the traverse 17 of the movable tube 18. Initially, the tube 18 is located and fixed on the reactor 19 with a liquid metal coolant 20.

Screw lift works as follows.

Before lifting the plug 18, a traverse 17 and a load (not shown) are installed on it, preventing the ascent of the plug, and the frame part 1 of the screw hoist is installed on the reactor lid 19. The protrusions 16 are inserted between the stops 11 and 12. The load and the pressure flange of the plug 18 are removed, holding it from vertical movement. The drive 6 is turned on, which rotates the drive shaft 7 with the gear 8 and, therefore, the combining gear 5. The rotation of the combining gear 5 leads to the simultaneous rotation of the gears 4 and, therefore, the spindles 3. The nuts 10 move the power block 9 upward in the thread the lead screws 3 and the guides 2. The movement of the power unit 9 leads to the lifting of the plug 18 with a traverse 17. In this case, the stops 11 and 12 move within the contact between the axes 13 and the grooves 14 and 15. When the plug 18 approaches the upper position, at which the ejection from la, acting on the stopper approaches zero, the groove 15 removes the upper supports 11 to the outer side of the tube. After complete removal of the upper stop 11, the operation of the drive 6 is stopped and the plug 18 through the yoke 37 is engaged with the capture of the lifting device of the protective suit. After the specified clutch, a certain rise in the plug is made and the further lifting of the power unit 9 is performed, in which the lower stops 12 are relegated similarly to the upper 11. After these operations, the plug is freely removed into the protective suit.

When installing the plug on the reactor, operations are performed in the reverse order of removing the plug from the reactor.

Claims (1)

A helical elevator interacting with a protective plug in the reactor lid, characterized in that it contains a frame structure serving as a power support for the drive, three spindles with gears engaged in gearing with a unifying gear wheel, power blocks with nuts moving along rectilinear guides with grooves on the spindles, while the power blocks are made with movable upper and lower stops, which contain axes that can slide into the horizontal grooves of the power blocks and vertical grooves of the guides, in the upper part of the guides the grooves have an inclined trajectory, which ensures the sequential removal of the upper and lower stops.

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