阅读说明：本技术 一种屏蔽主泵上部c型密封环内放射性残液疏排装置、方法 (Device and method for dredging and discharging radioactive residual liquid in C-shaped sealing ring on upper part of shielding main pump ) 是由 林鑫辉 耿加森 李松 李涛 董宝泽 王斌元 廖长城 王信东 曹阳 郦元辉 王扬 于 2019-08-28 设计创作，主要内容包括：一种屏蔽主泵上部C型密封环内放射性残液疏排装置、方法,属于核电站屏蔽主泵维修技术领域。装置包括真空废液罐、过滤器、真空泵、定距钻；定距钻定位于上部C型密封环上,用于定距开孔；定距钻的排液孔经管道与真空废液罐连接,真空废液罐经管道依次连接过滤器和真空泵。方法包括：步骤S01,在屏蔽主泵两根相邻的主螺栓间架设未安装手枪钻的定距钻,并确保定距钻的钻头密封抵在上部C型密封环上；步骤S02,按照定距钻、真空废液罐、过滤器和真空泵的顺序依次连接上述疏排装置；步骤S03,在通过真空废液罐上的真空表确认疏排装置内已变成负压,将手枪钻与钻头连接,启动手枪钻钻孔。本发明实现放射性残液不外漏至环境,避免现场工作人员和设备污染。(A device and a method for dredging and discharging radioactive residual liquid in a C-shaped sealing ring at the upper part of a shielding main pump belong to the technical field of maintenance of shielding main pumps of nuclear power stations. The device comprises a vacuum waste liquid tank, a filter, a vacuum pump and a fixed-distance drill; the distance drill is positioned on the upper C-shaped sealing ring and used for distance drilling; the liquid discharge hole of the distance drill is connected with a vacuum waste liquid tank through a pipeline, and the vacuum waste liquid tank is sequentially connected with a filter and a vacuum pump through pipelines. The method comprises the following steps: step S01, a distance drill without a gun drill is erected between two adjacent main bolts of the shielding main pump, and a drill bit of the distance drill is ensured to be tightly abutted against the upper C-shaped sealing ring; step S02, sequentially connecting the dredging device with a fixed-distance drill, a vacuum waste liquid tank, a filter and a vacuum pump; and step S03, confirming that the interior of the evacuation device is changed into negative pressure through a vacuum gauge on the vacuum waste liquid tank, connecting the pistol drill with the drill bit, and starting the pistol drill to drill. The invention realizes that the radioactive residual liquid does not leak to the environment, and avoids the pollution of field workers and equipment.)

1. a radioactive residual liquid dredging device in a C-shaped sealing ring at the upper part of a shielding main pump is characterized by comprising a vacuum waste liquid tank, a filter, a vacuum pump and a fixed-distance drill; the distance drill is positioned on the upper C-shaped sealing ring and used for distance drilling; and the liquid discharge hole of the distance drill is connected with the vacuum waste liquid tank through a pipeline, and the vacuum waste liquid tank is sequentially connected with the filter and the vacuum pump through pipelines.

2. The radioactive residual liquid drainage device in the C-shaped sealing ring at the upper part of the shielding main pump according to claim 1, wherein the distance drill comprises a drill bit, a drill chuck, a pistol drill and a supporting mechanism; the drill bit penetrates through the drill chuck, the head end of the drill bit is used for abutting against the upper C-shaped sealing ring to drill a hole, and the tail end of the drill bit is connected with the drill chuck of the pistol drill through the fixing ring; the front part of the drill chuck is designed with an intersecting line shape consistent with the upper C-shaped sealing ring, and the drill chuck is provided with a liquid discharge hole communicated with a drill bit passing through a channel; the supporting mechanism is used for supporting between two main bolts of the shielding main pump and applying pressure to the drill chuck, so that the drill chuck can be tightly attached to the upper C-shaped sealing ring.

3. the device for dredging radioactive residual liquid in the C-shaped sealing ring at the upper part of the shielding main pump according to claim 2, wherein the drill chuck comprises a drill chuck front cover and a drill chuck rear cover; and an irradiation-resistant sealing gasket is arranged between the drill chuck front cover and the drill chuck rear cover and is fastened through screws.

4. The device for thinning the radioactive residual liquid in the upper C-shaped sealing ring of the shielding main pump according to claim 3, wherein a first guide hole is formed in a front cover of the drill chuck, a second guide hole is formed in a rear cover of the drill chuck, the axes of the first guide hole and the second guide hole pass through the middle of the upper C-shaped sealing ring and are perpendicular to a tangent plane of a drill point, and the first guide hole and the second guide hole are used for guiding the drill bit to pass through the drill chuck.

5. The device for dredging radioactive residual liquid in the C-shaped sealing ring at the upper part of the shielded main pump according to claim 4, wherein a drill chuck cavity is arranged between the first guide hole and the second guide hole, and the diameter of the drill chuck cavity is larger than that of the first guide hole or the second guide hole.

6. The device for dredging radioactive residual liquid in the C-shaped sealing ring at the upper part of the shielding main pump according to claim 3, wherein the supporting mechanism comprises a first long inclined rod, a second long inclined rod, a first short inclined rod, a second short inclined rod, a first supporting claw, a second supporting claw, a supporting slide block, a locking handle, an eyebolt and an optical axis bolt nut; the supporting slide block is provided with a guide groove for accommodating the drill chuck rear cover; the first supporting claw and the second supporting claw are used for being respectively supported on the two main bolts; one end of the first long inclined rod is connected with the drill chuck, the other end of the first long inclined rod is connected with the first supporting claw, one end of the first short inclined rod is connected with the supporting sliding block, and the other end of the first short inclined rod is connected with the first supporting claw; one end of the second long inclined rod is connected with the drill chuck, the other end of the second long inclined rod is connected with the second supporting claw, one end of the second short inclined rod is connected with the supporting sliding block, and the other end of the second short inclined rod is connected with the second supporting claw; the lifting bolt is connected with the drill chuck through the optical axis bolt nut, and the relative displacement between the locking handle and the lifting bolt is adjusted through rotating the locking handle arranged at the tail end of the lifting bolt, so that the supporting slide block moves along the radial direction.

7. The radioactive residual liquid drainage device in the C-shaped sealing ring at the upper part of the shielded main pump according to claim 6, wherein the center of a rotating shaft of the first support claw and the first long inclined rod or the center of a rotating shaft of the second support claw and the second long inclined rod is B, the center of a circle of a cross section of a main bolt is O, the center of a rotating shaft of the first long inclined rod and the drill chuck or the center of a rotating shaft of the second long inclined rod and the drill chuck is A, the center of a rotating shaft of the first support claw and the first short inclined rod or the center of a rotating shaft of the second support claw and the second short inclined rod is C, the center of a rotating shaft of the first short inclined rod and the support slider or the center of a rotating shaft of the second short inclined rod and the support slider is D, a passing point C is a perpendicular line of a line segment AD, and an intersection point of the perpendicular line segment AD is E; the length relation on the same main bolt side satisfies: the sum of the lengths of the line segment AB and the line segment BO is greater than the length of the line segment AO, and the length of the line segment CD is greater than the length of the line segment CE.

8. The apparatus for discharging radioactive residual liquid in a C-shaped sealing ring at the upper part of a shielding main pump according to claim 1, wherein the filter comprises a first steel tank filled with soda lime, a second steel tank filled with activated carbon; the vacuum waste liquid tank is connected with the bottom of the first steel tank through a pipeline, the side wall of the first steel tank is connected with the bottom of the second steel tank through a pipeline, and the side wall of the second steel tank is connected with the vacuum pump through a pipeline.

9. a method for discharging radioactive residual liquid in a C-shaped sealing ring at the upper part of a shielded main pump, which is characterized in that the device for discharging the radioactive residual liquid in the C-shaped sealing ring at the upper part of the shielded main pump, which is disclosed by claim 2, is adopted, and the method comprises the following steps:

Step S01, a distance drill without a gun drill is erected between two adjacent main bolts of the shielding main pump, and a drill bit of the distance drill is ensured to be tightly abutted against the upper C-shaped sealing ring;

Step S02, sequentially connecting a radioactive residual liquid dredging device in a C-shaped sealing ring at the upper part of the shielding main pump according to the sequence of a fixed-distance drill, a vacuum waste liquid tank, a filter and a vacuum pump;

And step S03, confirming that the interior of the evacuation device is changed into negative pressure through a vacuum gauge on the vacuum waste liquid tank, connecting the pistol drill with the drill bit, and starting the pistol drill to drill.

10. the method for dredging radioactive residual liquid in the shielding C-shaped sealing ring at the upper part of the main pump according to claim 9, further comprising the step S04 of closing a valve at the exhaust port of the vacuum waste liquid tank if liquid flows in the pipeline and the vacuum waste liquid tank has liquid to be overturned after the upper C-shaped sealing ring is drilled through; if no liquid flows in the pipeline, the distance drill is detached, a hose for suction is connected with the pipeline, and the hose is inserted into the C-shaped ring drill hole at the upper part to suck the radioactive residual liquid below the height of the drill hole; after the residual liquid is completely absorbed, the valves of the water inlet and the exhaust port of the vacuum waste liquid tank are closed, and then the vacuum pump is closed.

Technical Field

The invention belongs to the technical field of maintenance of a shielding type main pump of a nuclear power station, and particularly relates to a device and a method for evacuating and discharging radioactive residual liquid in an upper C-shaped sealing ring before cutting the upper C-shaped sealing ring welded between a detachable part of the shielding type main pump and a pump shell in a high-radioactivity environment.

Background

After the nuclear power station runs for a long time, the possibility that other parts such as a main pump thrust bearing, a shielding sleeve and the like go wrong is gradually increased, so that the maintenance process is reasonably optimized and a special maintenance tool is developed to realize the overall replacement of the shielding main pump in a high-radioactivity environment.

The upper C-ring seal is an annular part welded between the main pump housing and the removable main pump assembly, with an inner diameter of 1599.18mm, which is the pressure boundary of the main pump. As shown in figure 1, the cross section is C-shaped, the thickness of both ends is 11.17mm, the thickness of the middle part is 6.35mm, the total height is 85.09mm, and the material is ASME SA-182F 304N. In the process of the whole replacement of the shielded main pump, firstly, the detachable main pump assembly needs to be removed from the pump shell, the upper C-shaped sealing ring needs to be cut, however, due to the structural characteristics of the shielded main pump, after the internal medium of the shielded main pump is drained through the lower drain valve, 40L of radioactive liquid still exists in the rear chamber area of the upper C-shaped sealing ring (such as A, B in fig. 2), and radioactive residual liquid splashes along the cutting seam when the upper C-shaped sealing ring is cut, so that field workers and equipment are contaminated. Therefore, a special device is needed to be designed for draining the radioactive residual liquid in the upper C-shaped sealing ring.

The difficult point that the interior raffinate of upper portion C type seal ring was dredged and is arranged has in combination shielding main pump's structural feature and on-the-spot arrangement condition: the radioactive residual liquid is difficult to collect, the device and the upper C-shaped sealing ring are difficult to seal, the drilling difficulty on the upper C-shaped sealing ring is large, the operation space is narrow, the foreign matter control difficulty and the evacuation progress pressure are large.

Chinese patent application CN201711270906.5 discloses a nuclear power is with shielding main pump Canopy seal ring drilling flow thinning device to specifically disclose flow thinning device includes the bottom plate, be equipped with the seal valve piece that can be at the horizontal direction back-and-forth movement on the bottom plate, be equipped with the ball valve in the seal valve piece, be equipped with the flowing back passageway on the seal valve piece, the front end of seal valve piece is equipped with sealed briquetting, the shape and Canopy seal ring appearance looks adaptation of sealed briquetting, sealed briquetting is opened along the fore-and-aft direction has the water conservancy diversion hole, be equipped with the drilling equipment at seal valve piece rear on the bottom plate, drilling equipment includes feed mechanism and installs the drill bit on feed mechanism, the drill bit can loop through ball valve, flowing back pipeline and water conservancy diversion hole. Although the borehole flow dredging device can realize borehole flow dredging of the Canopy sealing ring and prevent the coolant from splashing, residual liquid cannot be completely sucked.

disclosure of Invention

aiming at the problems in the prior art, the invention provides the radioactive residual liquid dredging and discharging device and method in the C-shaped sealing ring on the upper part of the shielding main pump, which have high reliability, can effectively suck the radioactive residual liquid completely and prevent the radioactive residual liquid from leaking to the environment.

the invention is realized by the following technical scheme:

The invention provides a radioactive residual liquid dredging device in a C-shaped sealing ring at the upper part of a shielding main pump, which comprises a vacuum waste liquid tank, a filter, a vacuum pump and a fixed-distance drill; the distance drill is positioned on the upper C-shaped sealing ring and used for distance drilling; and the liquid discharge hole of the distance drill is connected with the vacuum waste liquid tank through a pipeline, and the vacuum waste liquid tank is sequentially connected with the filter and the vacuum pump through pipelines.

By utilizing the vacuum suction principle, iron chips generated during drilling and radioactive residual liquid flowing out after drilling through the upper C-shaped sealing ring are sucked, so that the radioactive residual liquid is prevented from leaking to the environment, and the pollution of field workers and equipment is avoided.

Preferably, the distance drill comprises a drill bit, a drill chuck, a pistol drill and a supporting mechanism; the drill bit penetrates through the drill chuck, the head end of the drill bit is used for abutting against the upper C-shaped sealing ring to drill a hole, and the tail end of the drill bit is connected with the drill chuck of the pistol drill through the fixing ring; the front part of the drill chuck is designed with an intersecting line shape consistent with the upper C-shaped sealing ring, and the drill chuck is provided with a liquid discharge hole communicated with a drill bit passing through a channel; the supporting mechanism is used for supporting between two main bolts of the shielding main pump and applying pressure to the drill chuck, so that the drill chuck can be tightly attached to the upper C-shaped sealing ring.

Preferably, the drill chuck comprises a drill chuck front cover and a drill chuck rear cover; and an irradiation-resistant sealing gasket is arranged between the drill chuck front cover and the drill chuck rear cover and is fastened through screws.

Preferably, the drill chuck front cover is provided with a first guide hole, the drill chuck rear cover is provided with a second guide hole, the axes of the first guide hole and the second guide hole pass through the middle part of the upper C-shaped sealing ring and are perpendicular to a drilling point tangent plane, and the first guide hole and the second guide hole are used for guiding the drill bit to pass through the drill chuck.

Preferably, a drilling and clamping cavity is arranged between the first guide hole and the second guide hole, and the diameter of the drilling and clamping cavity is larger than that of the first guide hole or the second guide hole.

preferably, the support mechanism comprises a first long inclined rod, a second long inclined rod, a first short inclined rod, a second short inclined rod, a first support claw, a second support claw, a support slider, a locking handle, an eyebolt and an optical axis bolt nut; the supporting slide block is provided with a guide groove for accommodating the drill chuck rear cover; the first supporting claw and the second supporting claw are used for being respectively supported on the two main bolts; one end of the first long inclined rod is connected with the drill chuck, the other end of the first long inclined rod is connected with the first supporting claw, one end of the first short inclined rod is connected with the supporting sliding block, and the other end of the first short inclined rod is connected with the first supporting claw; one end of the second long inclined rod is connected with the drill chuck, the other end of the second long inclined rod is connected with the second supporting claw, one end of the second short inclined rod is connected with the supporting sliding block, and the other end of the second short inclined rod is connected with the second supporting claw; the lifting bolt is connected with the drill chuck through the optical axis bolt nut, and the relative displacement between the locking handle and the lifting bolt is adjusted through rotating the locking handle arranged at the tail end of the lifting bolt, so that the supporting slide block moves along the radial direction.

Preferably, the center of a rotating shaft of the first supporting claw and the first long inclined rod or the center of a rotating shaft of the second supporting claw and the second long inclined rod is B, the center of a circle of the cross section of the main bolt is O, the center of a rotating shaft of the first long inclined rod and the drill chuck or the center of a rotating shaft of the second long inclined rod and the drill chuck is A, the center of a rotating shaft of the first supporting claw and the first short inclined rod or the center of a rotating shaft of the second supporting claw and the second short inclined rod is C, the center of a rotating shaft of the first short inclined rod and the supporting slide block or the center of a rotating shaft of the second short inclined rod and the supporting slide block is D, a passing point C is a perpendicular line of the line segment AD, and the intersection point of the perpendicular line and the line segment AD is E; the length relation on the same main bolt side satisfies: the sum of the lengths of the line segment AB and the line segment BO is greater than the length of the line segment AO, and the length of the line segment CD is greater than the length of the line segment CE.

Preferably, the filter comprises a first steel tank filled with soda lime, a second steel tank filled with activated carbon; the vacuum waste liquid tank is connected with the bottom of the first steel tank through a pipeline, the side wall of the first steel tank is connected with the bottom of the second steel tank through a pipeline, and the side wall of the second steel tank is connected with the vacuum pump through a pipeline.

A radioactive residual liquid drainage method in a C-shaped sealing ring at the upper part of a shielding main pump adopts the radioactive residual liquid drainage device in the C-shaped sealing ring at the upper part of the shielding main pump, and the method comprises the following steps:

Step S01, a distance drill without a gun drill is erected between two adjacent main bolts of the shielding main pump, and a drill bit of the distance drill is ensured to be tightly abutted against the upper C-shaped sealing ring;

Step S02, sequentially connecting a radioactive residual liquid dredging device in a C-shaped sealing ring at the upper part of the shielding main pump according to the sequence of a fixed-distance drill, a vacuum waste liquid tank, a filter and a vacuum pump;

And step S03, confirming that the interior of the evacuation device is changed into negative pressure through a vacuum gauge on the vacuum waste liquid tank, connecting the pistol drill with the drill bit, and starting the pistol drill to drill.

The method also comprises a step S04, after the upper C-shaped sealing ring is drilled through, if liquid flows in the pipeline and the vacuum waste liquid tank has liquid to turn over, a valve of an exhaust port of the vacuum waste liquid tank is closed; if no liquid flows in the pipeline, the distance drill is detached, a hose for suction is connected with the pipeline, and the hose is inserted into the C-shaped ring drill hole at the upper part to suck the radioactive residual liquid below the height of the drill hole; after the residual liquid is completely absorbed, the valves of the water inlet and the exhaust port of the vacuum waste liquid tank are closed, and then the vacuum pump is closed.

The invention has the following beneficial effects:

the radioactive residual liquid dredging and discharging device and method in the C-shaped sealing ring on the upper part of the shielding main pump have higher reliability, small enough volume and weight and easy movement and transportation, can operate in a narrow area of the C-shaped sealing ring on the upper part of the main pump, realize positioning and distance drilling on the C-shaped sealing ring, prevent cuttings generated by drilling from entering the interior of the main pump, and have reliable sealing between the device and the C-shaped sealing ring on the upper part, effectively contain and collect the flowing radioactive residual liquid, can suck the residual liquid in the area below the drilling part, and can adsorb the flowing radioactive gas.

drawings

FIG. 1 is a cross-sectional view of a prior art top C-ring seal;

FIG. 2 is a schematic representation of a prior art radioactive raffinate in an upper C-ring seal;

FIG. 3 is a schematic structural view of a radioactive residual liquid drainage device in a C-shaped sealing ring at the upper part of a shielded main pump according to the present invention;

FIG. 4 is a schematic view of the construction of the distance drill of FIG. 3;

FIG. 5 is a cross-sectional view of the drill chuck of FIG. 4;

FIG. 6 is an assembled view of the distance drill of FIG. 4 mounted on the upper C-ring seal;

FIG. 7 is a schematic view of the support mechanism;

fig. 8 is a schematic flow chart of a method for draining radioactive residual liquid in a C-shaped sealing ring at the upper part of a shielded main pump according to the invention.

Detailed Description

The following are specific embodiments of the present invention and are further described with reference to the drawings, but the present invention is not limited to these embodiments.

referring to fig. 3, the radioactive residual liquid dredging device in the C-shaped sealing ring at the upper part of the shielded main pump comprises a vacuum waste liquid tank 2, a filter 3, a vacuum pump 4 and a distance drill 1. The distance drill 1 is positioned on the upper C-shaped sealing ring and used for distance drilling. The liquid discharge hole of the distance drill 1 is connected with the vacuum waste liquid tank 2 through a pipeline, and the vacuum waste liquid tank 2 is sequentially connected with the filter 3 and the vacuum pump 4 through pipelines.

The vacuum pump 4 is started to pump the interior of the device into negative pressure, so that liquid can be effectively prevented from leaking at the joint, and in the moment that the sealing ring is drilled through, cuttings can be sucked into the dredging device to be prevented from entering the main pump, and residual liquid can be sucked out quickly under the action of front-back pressure difference, so that the dredging efficiency is improved. The filter 3 is used to adsorb the radioactive gas in the device and prevent air pollution in the working area. The vacuum waste liquid tank 2 is used for collecting radioactive residual liquid and cutting scraps, and is convenient for subsequent unified treatment. The distance drill 1 is positioned and provided with a distance hole on the upper C-shaped sealing ring, and the radioactive residual liquid and cuttings flowing out are contained and sealed by utilizing the structure of the distance drill, so that the contamination of personnel and equipment is prevented. For the aspect of observing the evacuation condition of raffinate and guaranteeing that the pipeline can not be inhaled and held back, the connecting tube adopts transparent PVC steel wire hose between the equipment. The hose is connected with the joint of each device through a hose clamp, so that the hose is convenient to assemble and disassemble.

As shown in fig. 4-6, the distance drill comprises a drill bit 5, a drill chuck 6, a pistol drill 9 and a support mechanism 7. The drill bit 5 penetrates through the drill chuck 6, the head end of the drill bit 5 is used for abutting against the upper C-shaped sealing ring 10 to drill, and the tail end of the drill bit 5 is used for being connected with a drill rod connected with a pistol drill 9 through a fixing ring 8. The front part of the drill chuck 6 is designed with an intersecting line shape consistent with the upper C-shaped sealing ring, and the drill chuck 6 is provided with a liquid discharge hole 61 communicated with a drill bit passing channel. The supporting mechanism 7 is used for supporting between two main bolts 20 of the shielding main pump and pressing the drill clamp 6, so that the drill clamp 6 can be tightly attached to the upper C-shaped sealing ring 10. Once the drill bit drills through the C-ring, the radioactive raffinate can drain through the drain hole 61 of the distance drill.

The drill chuck 6 comprises a front chuck cover 62 and a rear chuck cover 63. An irradiation-resistant sealing gasket 65 such as an ethylene propylene diene monomer sealing gasket is arranged between the drill chuck front cover 62 and the drill chuck rear cover 63, and the sealing is realized through the fastening of screws. The front part of the drill chuck 6, namely a front cover 62 of the drill chuck, is provided with a circle of grooves around the open hole, and the grooves are internally provided with an irradiation-resistant sealing ring 64, such as an O-shaped ring made of ethylene propylene diene monomer, the interface diameter of the O-shaped ring is larger, so that enough deformation and sealing area are ensured, and residual liquid cannot leak from the upper C-shaped sealing ring when the drill chuck is tightly attached to the upper C-shaped sealing ring. The drill chuck front cover 62 is provided with a first guide hole 621, the drill chuck rear cover 63 is provided with a second guide hole 631, the first guide hole 621 with the diameter of the second guide hole 631 all matches with the drill bit diameter, the first guide hole 621 with the second guide hole 631 is used for guiding the drill bit 5 passes through the drill chuck 6, the first guide hole 621 with the axis of the second guide hole 631 passes through the middle of the upper C-shaped sealing ring and is perpendicular to the drilling point tangent plane, so that the drill chuck can drill a hole in the middle of the sealing ring without drilling deviation when tightly attaching to the upper C-shaped sealing ring. The back of the drill chuck, i.e. the back cover of the drill chuck, is provided with a skeleton oil seal 632 for preventing residual liquid from leaking between the drill chuck 6 and the drill bit 5. The cutting scraps of the stainless steel are not easy to cut off, the coiled materials are wound on the drill rod, in order to prevent the liquid drainage hole 61 from being blocked, a drilling clamp cavity 66 is arranged between the first guide hole and the second guide hole, and the diameter of the cavity is larger than that of the first guide hole or the second guide hole.

The supporting mechanism 7 is used for applying pressure to the drill chuck 6 by supporting two adjacent main bolts 20 of the drill hole, so that the drill chuck can be ensured to be tightly attached to the upper C-shaped sealing ring 10. In order to facilitate the disassembly and assembly and have the self-adaptability, the supporting mechanism 7 comprises a first long inclined rod 71, a second long inclined rod 72, a first short inclined rod 73, a second short inclined rod 74, a first supporting claw 75, a second supporting claw 76, a supporting slide block 77, a locking handle 78, an eyebolt 79 and an optical axis bolt nut 80. The supporting slide block is provided with a guide groove for accommodating the drill chuck rear cover. The two sides of the drill chuck rear cover are retracted inwards relative to the drill chuck front cover, the supporting slide block can move along the radial direction of the drill chuck rear cover under the constraint of the guide groove, and when the drill chuck rear cover moves to the position of the drill chuck front cover, the supporting slide block cannot move forwards under the limitation of the bottom of the drill chuck front cover. One end of the first long inclined rod 71 is connected to the drill chuck 6, the other end of the first long inclined rod is connected to the first supporting claw 75, one end of the first short inclined rod 73 is connected to the supporting slide block 77, and the other end of the first short inclined rod is connected to the first supporting claw 75. One end of the second long inclined rod 72 is connected to the drill chuck 6, the other end of the second long inclined rod is connected to the second support claw 76, one end of the second short inclined rod 72 is connected to the support sliding block 77, and the other end of the second short inclined rod is connected to the second support claw 76. The first supporting claw 75 and the second supporting claw 76 are used for being supported on two main bolts respectively. The first long diagonal bar 71, the second long diagonal bar 72, the first short diagonal bar 73, and the second short diagonal bar 74 form a symmetrical quadrilateral configuration with the support slider 77 as a center. The lifting bolt 79 is connected with the drill chuck 6 through the optical axis bolt nut 80, and the relative displacement between the locking handle 78 and the lifting bolt 79 is adjusted by rotating the locking handle 78 mounted at the tail end of the lifting bolt, so that the supporting slide block 77 moves along the radial direction.

In order to protect the main bolt 20, the curvature radius of the gripping surface of the first supporting claw 75 and the second supporting claw 76 is consistent with the radius of the section circle of the main bolt, and rubber pads are arranged. Because of the drill chuck and autogenous structural limitations, the support slide 77 can only move horizontally in the radial direction. As shown in fig. 7, the center of the rotation axis of the first supporting claw 75 and the first long diagonal bar 71 is B, the center of the cross-section circle of the main bolt 20 is O, the center of the rotation axis of the first long diagonal bar 71 and the drill chuck 6 is a, the center of the rotation axis of the first supporting claw 75 and the first short diagonal bar 73 is C, the center of the rotation axis of the first short diagonal bar 74 and the supporting slider 77 is D, the crossing point C is a perpendicular line of the line segment AD, and the intersection point of the perpendicular line and the line segment AD is E. The length relation of the main bolt on the left side satisfies: the sum of the lengths of the line segment AB and the line segment BO is greater than the length of the line segment AO, and the length of the line segment CD is greater than the length of the line segment CE. Similarly, the center of the rotating shaft of the second support claw 76 and the second long oblique rod 72 is B, the center of the cross section circle of the main bolt 20 is O, the center of the rotating shaft of the second long oblique rod 72 and the drill chuck 6 is a, the center of the rotating shaft of the second support claw 76 and the second short oblique rod 74 is C, the center of the rotating shaft of the second short oblique rod 74 and the support slider is D, the passing point C is a perpendicular line of the line segment AD, and the intersection point of the perpendicular line and the line segment AD is E; the length relation of the main bolt on the right side meets the following conditions: the sum of the lengths of the line segment AB and the line segment BO is greater than the length of the line segment AO, and the length of the line segment CD is greater than the length of the line segment CE.

The supporting slide block 77 is moved towards the upper C-shaped sealing ring 10, the supporting slide block 77 cannot move, the supporting claws 75 and 76 cannot move, the locking handle 78 is rotated, the eyebolt can rotate around the optical axis bolt, a pretightening force is applied to the supporting slide block 77 by utilizing the relative displacement of the locking handle 78 and the eyebolt 79, the supporting mechanism applies an acting force to the main bolt 20, the main bolt 20 has a reaction force to the supporting mechanism, a certain pressure is applied to a drill chuck, the more the locking handle 78 rotates, the greater the force applied to the drill chuck is, and the tighter the distance drill is clamped between the upper C-shaped sealing ring and two adjacent main bolts. When the support mechanism supports the main bolt, the lifting bolt is in a horizontal position. When the evacuation is finished, the locking handle 78 is rotated in the opposite direction, and the supporting slide block 77 is moved outwards to complete the removal of the distance drill. The eye screw 79 is connected to the drill chuck by means of a plain bolt nut 80, and can rotate around the plain bolt, and when the support mechanism is withdrawn, the eye screw is in a downward inclined position to avoid interference of the locking handle 78 with the withdrawn support slider 77.

the vacuum waste liquid tank is made of single-layer 304 stainless steel, and in view of radiation protection, collected liquid is discharged to a nearby floor drain as soon as possible after residual liquid in the upper C-shaped sealing ring is drained, so that a drain valve is designed at the lower part of the tank body, universal brake nylon wheels are designed on supporting legs, movement and positioning on the ground are facilitated, handles are symmetrically arranged on two sides of the tank body, and the vacuum waste liquid tank is convenient to carry when going upstairs and downstairs. Still be provided with the glass liquid level window on the jar body, have the liquid level scale mark on the window for observe the volume of collecting liquid and whether because of the liquid boiling condition that the jar internal pressure crossed the cause excessively. In order to effectively prevent residual liquid from being sucked into the air filter, the water pumping port and the air exhaust port are arranged at the top of the tank body, and in addition, isolation valves are arranged on the inlet and outlet pipelines, so that the waste liquid tank is conveniently isolated from the dredging device. The vacuum gauge is arranged at the top of the waste liquid tank, so that the vacuum degree in the tank can be conveniently monitored in real time. For guaranteeing the gas tightness of the waste liquid tank, the tank body is convenient to clean, and the tank cover and the tank body are designed to be connected through a stainless steel vacuum clamp.

the filter is designed to comprise a first steel tank filled with soda lime and a second steel tank filled with activated carbon; the vacuum waste liquid tank is connected with the bottom of the first steel tank through a pipeline, the side wall of the first steel tank is connected with the bottom of the second steel tank through a pipeline, and the side wall of the second steel tank is connected with the vacuum pump through a pipeline. The first steel tank and the second steel tank are 304 stainless steel tanks, and are erected on the ground by using 304 stainless steel frames, and the stainless steel frames are used for fixing the steel tanks and facilitating integral movement. The tank cover is connected with the tank body through a stainless steel vacuum clamp, so that the air sealing of the tank body can be ensured, and the filling and the replacement of the activated carbon and the soda lime are facilitated. In order to ensure the full contact of the sucked mixed gas with the soda lime and the activated carbon and improve the filtering effect, the process is designed in such a way that the mixed gas firstly enters from the bottom of a steel tank filled with the soda lime, flows out from the side wall, the moisture in the gas is filtered, then enters from the bottom of the steel tank filled with the activated carbon, flows out from the side wall, and the radioactive gas in the gas is filtered.

The vacuum pump is designed to be a jet vacuum pump with small volume, light weight, high reliability and simple maintenance.

Referring to fig. 8, a method for discharging radioactive residual liquid in a C-shaped sealing ring at the upper part of a shielded main pump, which adopts the device for discharging radioactive residual liquid in a C-shaped sealing ring at the upper part of a shielded main pump, includes:

step S01, a distance drill without a gun drill is erected between two adjacent main bolts of the shielding main pump, and a drill bit of the distance drill is ensured to be tightly abutted against the upper C-shaped sealing ring;

Step S02, sequentially connecting a radioactive residual liquid dredging device in a C-shaped sealing ring at the upper part of the shielding main pump according to the sequence of a fixed-distance drill, a vacuum waste liquid tank, a filter and a vacuum pump;

and step S03, confirming that the interior of the evacuation device is changed into negative pressure through a vacuum gauge on the vacuum waste liquid tank, connecting the pistol drill with the drill bit, and starting the pistol drill to drill.

in step S01, a distance drill (removed pistol drill) is set between two adjacent main bolts according to actual conditions on site, it is confirmed that the distance drill and the upper C-shaped sealing ring are well sealed, then the head of the drill bit is abutted against the upper C-shaped sealing ring, and the fixing ring is fixed at the corresponding position of the drill rod according to the required moving distance.

In step S03, the vacuum pump is started, it is confirmed that the inside of the device has become negative pressure and the vacuum degree is not changed through the vacuum gauge on the vacuum waste liquid tank, the pistol drill is connected to the drill bit, the pistol drill is set at a low rotation speed (about 100-200 rpm), the pistol drill is started to start drilling, the process is kept stable and the direction is stabilized, and when the upper C-shaped sealing ring is about to be drilled through, the pressure is reduced, and the drill bit is prevented from being damaged. When the drill bit needs to be replaced in drilling, the negative pressure in the device is firstly confirmed, and the framework sealing is carefully damaged when the drill bit is pulled out.

The method also comprises a step S04, after the upper C-shaped sealing ring is drilled through, if liquid flows in the pipeline and the vacuum waste liquid tank has liquid to turn over, a valve of an exhaust port of the vacuum waste liquid tank is closed; if no liquid flows in the pipeline, the distance drill is detached, a hose for suction is connected with the pipeline, and the hose is inserted into the C-shaped ring drill hole at the upper part to suck the radioactive residual liquid below the height of the drill hole; after the residual liquid is completely absorbed, the valves of the water inlet and the exhaust port of the vacuum waste liquid tank are closed, and then the vacuum pump is closed.

It will be appreciated by persons skilled in the art that the embodiments of the invention described above and shown in the drawings are given by way of example only and are not limiting of the invention. The objects of the present invention have been fully and effectively accomplished. The functional and structural principles of the present invention have been shown and described in the examples, and any variations or modifications of the embodiments of the present invention may be made without departing from the principles.