RU2166808C1 - Plug remover - Google Patents

Abstract

FIELD: repairs involving replacement of spent flowmeters. SUBSTANCE: remover has body with cylindrical seat, snap ring clamping mechanism with set of radial movable pins kinematically coupled with plug extractor made in the form of hydraulic-control vertically moving annular rod actuating bottom end of plug through its butt-end surface . Shaped annular slot actuating the pins and vertical slots are provided on outer surface of rod. Body is built up of concentric tubes; internal tube has end lids on its outer surface joined with cylindrical surface of annular rod; pins are installed on inner surface of external tube. EFFECT: reduced manual labor consumption, improved reliability, reduced radiation dose absorbed by personnel. 5 dwg

Description

 The proposed technical solution relates to the operation technique of RBMK-type nuclear power reactors and can be used during repair work to replace ShADR-32M ball throttle flow meters that have exceeded the standard deadline. The indicated flowmeters are installed on each loop of the lower water supply circulating water supply of each technological channel. Each year, at each power unit with a RBMK-1000 reactor, 400 flow meters are subject to replacement. For a number of technological reasons, after removing the flowmeter from the reactor circulation loop, it is necessary to remove the plug from it. The plug is connected to the flowmeter body with an internal spring radial split ring. At the location of the ring, the flowmeter body has a group of radial holes that, by acting on the ring with external forces, compress it, thereby disengaging the tube with the body of the flowmeter and axially moving the tube to remove it with the ring from the body of the flowmeter.

 Known puller, which can be used to remove the plug from the ball throttle flowmeter of the coolant in the technological channels of a water-graphite nuclear reactor, containing a housing with a cylindrical socket for accommodating the flowmeter, a mechanism for compressing the locking ring with a group of radially movable fingers spring-loaded relative to the housing, kinematically connected with the mechanism extraction plugs. In the known puller, a mechanism for compressing the locking ring with a group of radially movable fingers located in the radial channels of the housing is manually actuated by an angular rotation covering the casing of the cage with an internal ratchet, setting the law and the amount of movement of the fingers in the direction of the locking ring of the flowmeter. However, there are no unambiguous criteria for the force of the fingers on the locking ring. As a result, fingers, compressing the locking ring, simultaneously clamp the cylindrical shank of the plug, which prevents its subsequent removal from the flow meter. The mechanism for extracting the plug is a master nut driven manually from the winch with a fixed lead screw, temporarily fixed, again manually, in the threaded socket on the plug.

и работа с ним требует минимального применения ручного труда.Thus, the disadvantages of the known puller arise from the design described above - this is a high proportion of manual labor and the unreliability of the mechanism for extracting the cork. It should be borne in mind that the flow meter extracted from the coolant circuit has a high degree of radioactive contamination with radionuclides of corrosive origin. The radiation power from the flow meter reaches

and working with it requires minimal manual labor.

 The aim of the invention is to reduce the proportion of manual labor when removing the plug from the flowmeter, increasing the reliability of the mechanism for extracting the plug and reducing the absorbed dose of radiation to personnel.

 This goal is achieved due to the fact that in the plug puller containing a housing with a cylindrical socket, a mechanism for compressing the locking ring with a group of radially movable fingers spring-loaded relative to the housing kinematically connected with the plug extraction mechanism, the extraction mechanism is made in the form of a hydraulically controlled vertically movable ring rod, with its end surface acting on the lower end of the tube with the annular profiled on the outer surface of the rod facing the lower end of the tube with a flute groove acting on the fingers and vertical grooves mating with the fingers, while the body is made in the form of concentrically arranged and interconnected lower end surfaces of the pipes, the inner of which contains end caps mating with the cylindrical surface of the stem of the plug extraction mechanism, and the fingers are mounted on the inner surface of the outer pipe of the housing.

 A comparative analysis of the proposed technical solution with the prototype allowed us to identify distinctive features, which proves the conformity of the claimed combination of features to the criteria of the invention of "novelty."

 When searching for analogues and prototype, no technical solutions were found that are similar to the distinguishing features of the proposed solution, which proves the conformity of the claimed combination of features to the criteria of the invention "inventive step".

The essence of the proposal is illustrated from the consideration of the drawings, on which
FIG. 1 - sectional plug of the flow meter;
FIG. 2 is a view A from FIG. 1;
FIG. 3 is a view B of FIG. 2:
FIG. 4 is a section DD from FIG. 1;
FIG. 5 is a section EE from FIG. 1.

 The plug of the plug from the flowmeter (the ball throttle flowmeter in Fig. 1 is shown by the SHADR-32M leader) is a vertical casing 1 of two concentrically arranged pipes - inner 2 and outer 3. Both pipes are attached to the flange 4 by the lower end surfaces and are connected between the flange 4 and between by myself. In turn, the flange 4 is attached to the base 5 with height-adjustable supports 6 to ensure the vertical position of the puller.

 Inside the housing 1 there is a vertical cylindrical socket, in which the flowmeter is placed with the head 7 down, the cork 8 up. The plug is fixed on the flowmeter body from axial displacement by a spring radially split lock ring 9, which, being in a free state, overlaps the annular grooves in the cylindrical shank of the plug 8 and in the cylindrical body of the flow meter. The puller contains a mechanism 10 for compressing the locking ring 9 and the extraction mechanism 11 of the tube 8.

 The mechanism 10 (Fig. 3) for compressing the locking ring is made in the form of a group of radially movable fingers 12 spring-loaded relative to the housing 1. Moreover, each of the radially movable fingers is mounted on the inner surface of the outer pipe 3 of the housing 1 and is spring-loaded in the direction of movement of the finger toward the center puller. In the annular gap between the inner 2 and outer 3 pipes of the casing 1, the extraction mechanism 11 of the plug 8 is arranged concentrically to the flowmeter. The mechanism 11 is made in the form of a hydraulically controlled vertically movable annular rod 13. On the outer surface of the inner pipe 2 of the casing 1 there are clamps 14 and 15 attached to it , which are the end caps of the cylinder, paired with its cylindrical surface. An annular piston 16 is attached to the inner surface of the rod 13, which divides the fluid-filled space into upper and lower cavities, respectively, “VP” and “NP” (Fig. 1). On the outer surface of the rod 13, facing the lower end of the plug 8, an annular profile groove “L” and vertical grooves “M” conjugated with the fingers 12 are made. At the same time, rollers 17 are installed on each of the fingers 12 (Fig. 3), which interact with the profile of the groove "L" and in the initial state of the puller hold the radially movable fingers 12 in the extreme position allotted from the flowmeter. The puller has diameters 18 mounted diametrically opposite on the inner pipe 2, locking the flowmeter in the puller and preventing the axial and circular movement of the flowmeter relative to the housing 1. An annular groove "H" is made on flange 4 for collecting and organized drainage through vertical holes in the base of 5 leakages liquid from the cavity between the body 2 and the rod 13 of the extraction mechanism 11 into the pan 19 installed on the base 5. For alternately filling or emptying the cavities “VP” and “NP” of the extraction mechanism Section 11 with the working fluid there are media separators 20 and 21 attached to the outer pipe 3 of the housing 1 of the puller, filled with the working fluid. Both pressure cavities of the separators are connected by flexible pipelines 22 and 23 with the corresponding upper cavities ("VP") and lower cavities ("NP") of the rod 13 of the extraction mechanism 11. The control cavities of the media separators are connected through a four-way valve 24 and valve 25 to the process water line. In each of the cavities of the cylinder formed by the inner tube 2 of the housing 1 with end collars 14 and 15, i.e. with end caps and a stem 13 of the extraction mechanism 11 with a piston 16, screws 26 are installed to remove air from the cylinder.

 As follows from the design of the stripper described above, a highly active flowmeter is located in the central cavity of several concentrically arranged pipe structures, which noticeably attenuate radioactive radiation from the flowmeter, which creates biologically favorable working conditions for personnel.

 To prepare the puller for operation, the outlet of the crane 24 (Fig. 2) is informed with a drain path (not shown) with sewage. Connect the inlet of the closed valve 25 to the network of process water. The separator 21 is filled with working fluid until the working fluid appears in the hole "P", after which the screw 26 holes. "P" and the plug 27 of the filler neck 28 (Fig. 2) of the separator 21 are tightened to the stop. Turn the crank handle 24 towards the separator 21. Having opened the valve 25, the working fluid is fed into the "NP" cavity (Fig. 1) and the annular piston with the rod 13 is lifted to the end of the piston 16 against the end of the cover 14. The valve 25 is closed. The separator is filled with working fluid 20 to the appearance of the working fluid in the holes. "P", after this screw 26 holes. The "P" and the plug 29 of the filler neck 30 and the separator 20 are tightened to the stop. Turn the handle of the crane 24 towards the separator 20. Having opened the valve 25, feed the working fluid into the cavity "VP", lower the annular piston 16 with the rod 13 until the piston 16 stops in the shoulder 15 of the housing 2. Close the valve 25.

 The flow plug tube works as follows.

 A flowmeter (SHADR-32M) installed in a vertical cylindrical socket of the housing 1 (Fig. 1), previously oriented relative to radially movable fingers 12 by the holes of the SHADR-32M housing, is clamped with locks 18 to prevent its vertical and circular movements.

 In the initial position of the puller, the rod 13 (Fig. 1) is lowered, the handle of the crane 24 (Fig. 2) is turned towards the separator 20, the valve 25 is closed.

 When applying the working fluid to the cavity "NP" (Fig. 1), the piston 16 moves the rod 13 up.

 When the rollers 17 of the fingers 12 move from the upper cylindrical belt to the conical belt of the profile groove "L" of the rod 13, the fingers 12 under the influence of the mechanism 10 move in the radial holes of the cover 14 in the radial direction.

 When the rollers 17 of the fingers 12 move to the middle cylindrical belt of the "L" surface, the fingers 12 act on the locking ring 9, squeeze it and remove it from the groove of the SHADR-32M body, recessing the plugs 8 in the groove of the shank.

 Continuing the upward movement of the rod 13, the upper end starts to push the plug 8 out of the SHADR-32M body, while simultaneously holding the ring 9 in a compressed position.

 When the rollers 17 of the fingers 12 move to the lower conical belt of the surface “L” of the rod 13, the rollers 17, acting on the springs of the mechanism 10, squeeze them, moving the fingers 12 from the ring 9. Continuing the upward movement of the rod 13, the top end extends the plug 8 from the SHADR-32M case . In this case, the rollers 17 of the fingers 12, moving along the lower cylindrical belt of the surface "L", hold the fingers 12 outside the vertical cylindrical socket of the housing 1. Remove the plug 8 with the ring 9 manually.

 Clips 18 are retracted, ShADR-32M is removed from the cylindrical socket of the housing 1.

 When the working fluid is supplied into the "VP" cavity, the rod 13 returns to its lowest position. The fingers 12 are returned to their original position (Fig. 1), the valve 25 (Fig. 2) is closed.

 Thus, the combined fulfillment of the features of the puller described above reduces the share of manual labor in removing the plug from the flowmeter, increases the reliability of the puller, reduces the radiation power and, as a result, creates more favorable medical conditions for the staff to work.

Sourse of information
RF patent N 2009868, IPC class ⁶ B 25 B 27/00, publication date 03/30/94.

Claims (1)

 A plug puller comprising a housing with a cylindrical socket, a mechanism for compressing the locking ring with a group of radially movable fingers spring loaded relative to the housing kinematically connected with the plug extraction mechanism, characterized in that the plug extraction mechanism is made in the form of a hydraulically controlled vertically movable ring rod, its end the surface of the stopper acting on the lower end face with the annular profile groove made on the outer surface of the stem facing the lower end face of the stopper existing on the fingers, and vertical grooves mating with the fingers, while the casing is made in the form of concentrically arranged and interconnected lower end surfaces of the pipes, the inner of which contains end caps mating with the cylindrical surface of the annular rod of the tube extraction mechanism, and the fingers are mounted on the inner surface of the outer pipe of the housing.

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