Flame cutting head arrangement, underwater cutting apparatus and underwater cutting method

Abstract

The application discloses a cutting head device for flame cutting, which comprises a first pipe body, a second pipe body and a third pipe body arranged in sequence from inside to outside, the second pipe body is sleeved outside the first pipe body, and the third pipe body is sleeved outside the second pipe body; a first gas passage is formed in the first pipe body, a second gas passage is formed between the second pipe body and the first pipe body, and a third gas passage is formed between the third pipe body and the second pipe body. The cutting head device for flame cutting has three gas passages formed by the three pipe bodies, the third gas passage and the second gas passage are annular passages, the gas in the first gas passage and the second gas passage is mixed and ignited to form a flame for flame cutting, and the gas in the third gas passage is used for forming an air cavity on the surface of a workpiece to be cut and discharging water in the air cavity when the workpiece is cut underwater, so that the flame in the air cavity can be sustained, and underwater flame cutting is realized.

Description

Technical Field

[0001] This invention belongs to the field of radioactive metal cutting technology, and particularly relates to a cutting head device suitable for underwater flame cutting, an underwater cutting device including the cutting head device, and a method for underwater flame cutting using the cutting head device. Background Technology

[0002] In nuclear power plant decommissioning projects, large radioactive metal components need to be cut and prepared to reduce space occupancy and achieve the goal of reducing waste disposal volume. Radioactive metal components from decommissioned and scrapped nuclear power plants are characterized by their large thickness and high radiation dose.

[0003] Cutting methods for thick-walled metals include flame cutting, mechanical cutting, and water jet cutting. Among them, flame cutting is the most mature cutting process for cutting thick steel plates (thickness > 100 mm) in industry. It has the largest thickness, the fastest speed, and the highest efficiency. However, it generates a large amount of aerosol during cutting, and the radioactive dose of the cut parts is high, resulting in a high radiation dose to personnel. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide a cutting head device suitable for underwater flame cutting, which enables underwater flame cutting of workpieces.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A flame cutting head device includes a first tube, a second tube, and a third tube arranged sequentially from the inside out. The second tube is sleeved outside the first tube, and the third tube is sleeved outside the second tube. A first gas channel is formed inside the first tube, a second gas channel is formed between the second tube and the first tube, and a third gas channel is formed between the third tube and the second tube. Both the second and third gas channels are annular.

[0007] According to some preferred embodiments of the present invention, a combustion-supporting gas, such as oxygen, is introduced into the second gas channel, and a combustible gas is introduced into the first gas channel. The gases in the first and second gas channels are mixed and ignited to form a flame for flame cutting. The gas in the third gas channel is used to form a gas cavity on the surface of the workpiece to be cut during underwater cutting and to discharge the water in the gas cavity, so that the flame in the gas cavity can be sustained, thereby realizing underwater flame cutting.

[0008] According to some preferred embodiments of the invention, the outlet of the third gas passage is oriented away from the first tube; and / or the outlet of the second gas passage is oriented towards the first tube.

[0009] According to some preferred embodiments of the present invention, the cross-sectional area ratio of the first gas channel, the second gas channel, and the third gas channel is 1:2 to 3:0.6 to 0.8.

[0010] According to some preferred embodiments of the present invention, the gas flow rate at the outlet of the first gas channel is 50-75 m³ / h. 3 / h; the gas flow rate at the outlet of the second gas channel is 100-150m³ / h. 3 / h; the gas flow rate at the outlet of the third gas channel is 30-60m³ / h. 3 / h.

[0011] According to some preferred embodiments of the invention, the lower end of the second tube has a first part and a second part, the first part being inclined from top to bottom toward the first tube, and the second part being inclined from top to bottom toward a direction away from the first tube; and / or the lower end of the third tube is inclined from top to bottom toward a direction away from the first tube.

[0012] According to some preferred embodiments of the present invention, the angle between the first part and the vertical plane is 8 to 12°; the angle between the second part and the vertical plane is 12 to 18°; and the angle between the lower end of the third tube and the vertical plane is 12 to 18°.

[0013] According to some preferred embodiments of the invention, the tilt angle of the second part is the same as the tilt angle of the lower end of the third tube.

[0014] According to some preferred embodiments of the present invention, a first intake pipe and a second intake pipe distributed around the outer periphery of the first intake pipe are included, wherein the first intake pipe and the second intake pipe extend in the same direction; the first intake pipe is connected to a first gas channel, and the second intake pipe is connected to a second gas channel and a third gas channel.

[0015] According to some preferred embodiments of the present invention, a plurality of second intake pipes are evenly spaced around the outer periphery of the first intake pipe with the center line of the first intake pipe as the center.

[0016] According to some preferred embodiments of the invention, a connecting plate is included for adjacent pipe bodies, the connecting plate having a through hole extending through its wall thickness.

[0017] According to some preferred embodiments of the invention, a connecting ring is included for connecting the intake pipe and the pipe body.

[0018] The present invention also provides an underwater cutting device, including a cutting pool, a frame disposed in the cutting pool, a platform, and a cutting head device as described above. The frame includes a crossbeam, an execution arm is disposed on the crossbeam, and the cutting head device is disposed at the lower end of the execution arm.

[0019] According to some preferred embodiments of the invention, a water inlet unit and / or a water outlet unit are connected to the space inside the cutting pool. The water inlet unit includes a water inlet pipe and a water inlet valve disposed on the water inlet pipe. The water outlet unit includes a water outlet pipe and a monitoring component and a water outlet valve disposed on the water outlet pipe.

[0020] According to some preferred embodiments of the present invention, the drainage pipe is further provided with a filter, a water pump, a circulation pipe, and a circulation water valve provided on the circulation pipe, the circulation pipe connecting the cutting pool and the drainage pipe.

[0021] According to some preferred embodiments of the present invention, an exhaust unit is included, the exhaust unit comprising a gas collection hood, an exhaust pipe, a filter disposed on the exhaust pipe, and an exhaust fan, the gas collection hood being disposed above the cutting head device, and the exhaust pipe communicating with the gas collection hood.

[0022] The present invention also provides an underwater cutting method, comprising the following steps:

[0023] A first gas channel, a second gas channel, and a third gas channel are formed, wherein the second gas channel is annularly surrounding the outer periphery of the first gas channel, and the third gas channel is annularly surrounding the outer periphery of the second gas channel;

[0024] Gas is introduced into the second and third gas channels to form an air cavity on the surface of the workpiece to be cut and to discharge the water in the air cavity to the outside of the air cavity;

[0025] Gas is introduced into the first gas channel, and the gas in the first gas channel mixes with the gas in the second gas channel to form a cutting flame, which is used to cut the workpiece to be cut.

[0026] Due to the adoption of the above technical solutions, the advantages of the present invention compared with the prior art are as follows: The cutting head device for flame cutting of the present invention forms three gas channels by setting three types of tubes. The third gas channel and the second gas channel are both annular channels. The gases in the first gas channel and the second gas channel are mixed and ignited to form a flame for flame cutting. The gas in the third gas channel is used to form an air cavity on the surface of the workpiece to be cut during underwater cutting and to discharge the water in the air cavity, so that the flame in the air cavity can be sustained, thereby realizing underwater flame cutting. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the main structure of the underwater cutting device in a preferred embodiment of the present invention;

[0029] Figure 2 This is a top view of the underwater cutting device in a preferred embodiment of the present invention.

[0030] Figure 3 This is a side view of the underwater cutting device in a preferred embodiment of the present invention.

[0031] Figure 4 This is a schematic diagram of the cutting head device for flame cutting in a preferred embodiment of the present invention;

[0032] Figure 5 This is a schematic diagram of the cutting head device during cutting in a preferred embodiment of the present invention. Detailed Implementation

[0033] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0034] To address the radiation shielding issue for workers during aerosol filtration and cutting, this invention discloses a cutting head device suitable for underwater flame cutting, an underwater cutting device including the cutting head device, and a method for underwater flame cutting of radioactive metal waste using the cutting head device. This achieves efficient flame cutting while simultaneously providing efficient biological shielding of radiation doses during the cutting process, efficient absorption and treatment of radioactive aerosols, and efficient absorption of insoluble radioactive gases.

[0035] The reference numerals and brief descriptions of the components in the attached drawings are shown in Table 1 below:

[0036] Table 1. Figure Labels and Brief Descriptions

[0037]

[0038]

[0039] Example 1: Underwater Cutting Equipment

[0040] The underwater cutting equipment of this embodiment includes a cutting pool, a frame and a platform disposed in the cutting pool, a water inlet unit, a drainage unit and an exhaust unit communicating with the space inside the cutting pool, and a cutting head device for underwater cutting. The frame includes a crossbeam, and an execution arm is disposed on the crossbeam. The cutting head device is disposed at the lower end of the execution arm.

[0041] The water inlet unit includes an inlet pipe and an inlet valve installed on the inlet pipe. The drainage unit includes a drainage pipe and, in sequence, a filter, a monitoring component (dose monitor), a water pump, a drain valve, a circulation pipe, and a circulation valve. One end of the circulation pipe is connected between the water pump and the drain valve, and the other end is connected to the cutting pool, communicating with the internal space of the cutting pool to achieve water circulation.

[0042] The exhaust unit includes a gas collection hood, an exhaust pipe, a filter and an exhaust fan arranged sequentially on the exhaust pipe, and the gas collection hood is positioned above the cutting head device. The exhaust pipe is connected to the gas collection hood.

[0043] This embodiment describes a cutting head device suitable for underwater flame cutting, comprising a first air inlet pipe (oxygen inlet pipe), second air inlet pipes (gas inlet pipes) distributed around the outer periphery of the first air inlet pipe, a first pipe body, a second pipe body, and a third pipe body arranged sequentially from the inside out, a connecting plate and a connecting ring, and an igniter disposed on the inner wall of the first pipe body. The first and second air inlet pipes extend in the same direction. Multiple second air inlet pipes are evenly spaced around the outer periphery of the first air inlet pipe, with the center line of the first air inlet pipe as the center. The first air inlet pipe communicates with the first pipe body, and the second air inlet pipes communicate with the second and third pipe bodies. The connecting plate is used for adjacent pipe bodies, and has through holes penetrating its wall thickness; the connecting ring is used to connect the air inlet pipes and the pipe bodies.

[0044] The first pipe is used to supply gas, while the second and third pipes are used to supply oxidizing gases such as oxygen. The igniter is located on the inner wall of the outlet section of the first pipe to ignite the gas and oxidizing gas to form a flame. The igniter lead can be embedded inside the channel wall.

[0045] The second tube is fitted over the first tube, and the third tube is fitted over the second tube. A first gas passage (fuel combustion passage) is formed inside the first tube, a second gas passage (oxygen combustion passage) is formed between the second tube and the first tube, and a third gas passage (oxygen purging passage) is formed between the third tube and the second tube. Both the second and third gas passages are annular, preferably circular, meaning the intake pipe and the tube body are circular.

[0046] The outlet of the third gas passage faces away from the first tube, and the outlet of the second gas passage faces towards the first tube. Specifically, the lower end of the second tube has a first part and a second part, the first part is inclined from top to bottom towards the first tube, and the second part is inclined from top to bottom away from the first tube; and / or the lower end of the third tube is inclined from top to bottom away from the first tube, and the inclination angle of the second part is the same as the inclination angle of the lower end of the third tube. In this embodiment, preferably, the angle between the first part and the vertical plane is 8-12°; the angle between the second part and the vertical plane is 12-18°; and the angle between the lower end of the third tube and the vertical plane is 12-18°.

[0047] The cross-sectional area ratio of the first, second, and third gas channels is 1:2–3:0.6–0.8. Through the design of the through holes in the connecting plate, the cross-sectional area of ​​the gas channels, the inlet flow rate, and the size of the pipe outlet, the gas flow rate at the outlet of the first gas channel is 50–75 m³ / h. 3 / h; the gas flow rate at the outlet of the second gas channel is 100-150m³ / h. 3 / h; the gas flow rate at the outlet of the third gas channel is 30-60m³ / h. 3 / h, combined with the angled inclination of the lower end of the tube, to better form a gas cavity and ensure the flame cutting process.

[0048] Example 2: Underwater Cutting Method

[0049] This embodiment provides a method for underwater cutting of radioactive metal waste based on the underwater cutting equipment in Embodiment 1, including the following steps:

[0050] Step 1) Hoist the workpiece 18 to be cut onto the grid frame 13.

[0051] Step 2) Remotely operate the gantry frame 22 to move the flame cutting head device 20 above the workpiece 18.

[0052] Step 3) Close the manhole door 11 of the cutting pool and close the water valves 19A and 19B.

[0053] Step 4) Open the water inlet valve 12 and inject water into the cutting pool 10. The final water level is slightly lower than that of the gas collection hood 25.

[0054] Step 5) Turn on the underwater TV 24.

[0055] Step 6) Turn on the exhaust fan 28, and a slight negative pressure is formed inside the air collection hood 26.

[0056] Step 7) The remote control cutting head device 20 is ventilated and cuts the workpiece 18 according to the specified path.

[0057] The specific process of ventilation and cutting is as follows:

[0058] Oxygen is introduced into the second and third gas tubes through the second inlet pipe. The oxygen enters the second and third gas channels and exits from the ends of the channels. With the cutting head structure fixed, the outlet airflow can be controlled by adjusting the inlet airflow. This creates two annular flow channels after the gas exits from the second and third gas channels; the annular air curtain forms an air chamber on the surface of the workpiece to be cut. Slightly moving the cutting head back and forth and left and right blows away the water on the workpiece surface, expelling the water from the air chamber. The gas flow rate in the second and third gas channels remains stable to maintain this air chamber.

[0059] Next, combustible gas is introduced into the first gas channel, and the gas flow rate is adjusted to match the oxygen flow rate, forming a combustible flow ratio. The gas in the first gas channel mixes with the gas in the second gas channel, and a remotely controlled igniter is used to ignite and form a cutting flame for cutting the workpiece.

[0060] At the initial stage of gas chamber formation, the two annular channels formed by the outlets of the second and third gas channels are used to form the gas chamber and expel water from it. After ignition and cutting, the gas in the inner annular channel is used to form a cutting flame with the combustible gas, while the gas in the outer annular channel is used to maintain the gas chamber and ensure the flame inside the chamber remains continuous.

[0061] Step 8) Turn on water pump 17 and water valve 19A to circulate the water in pool 10 and purify the water quality.

[0062] When filter 15 needs to be replaced, follow these steps:

[0063] 1) If the dose monitor 16 alarms during the cutting process, the cutting operation will be stopped and the water pump 17 will be stopped.

[0064] 2) Close water valves 19A and 19B;

[0065] 3) Replace with a new filter 15;

[0066] 4) Open water valves 19A and 19B, start water pump 16, and continue cutting operations.

[0067] When it is necessary to replace the medium in the cutting pool 10, follow these steps:

[0068] 1) Close water valve 19A and open water valve 19B;

[0069] 2) Start water pump 16 and discharge the water in the cutting pool through water valve 19B;

[0070] 3) After the water has been drained, close water valves 19A and 19B;

[0071] 4) Open water valve 12 to inject water into the cutting pool 10.

[0072] Compared to traditional dry-environment flame cutting of radioactive metals, the underwater cutting equipment and method of this invention have the following advantages: The structural design of the flame cutting head enables underwater flame cutting of workpieces. Underwater cutting facilitates the absorption and removal of radioactive materials; most of the radioactive aerosols generated during flame cutting dissolve in the water, and as the water pump circulates the water, the radioactive materials are filtered and absorbed. All insoluble gases are collected by a gas collection hood, and the radioactive materials in the gases are absorbed by a filter. The cutting pool, as a water entity, provides excellent radiation shielding, and the entire cutting operation is remotely controlled, significantly reducing the radiation dose to cutting personnel.

[0073] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. An underwater cutting device suitable for radioactive metal waste, characterized in that, The device includes a cutting pool, a frame and a platform set inside the cutting pool, and a cutting head device for flame cutting. The frame includes a crossbeam, an execution arm is set on the crossbeam, and the cutting head device is set at the lower end of the execution arm. It includes a water inlet unit and a drainage unit that communicate with the space inside the cutting pool. The water inlet unit includes a water inlet pipe and a water inlet valve installed on the water inlet pipe. The drainage unit includes a drainage pipe and a monitoring component and a drainage valve installed on the drainage pipe. The device includes an exhaust unit, which comprises a gas collection hood, an exhaust pipe, a filter installed on the exhaust pipe, and an exhaust fan. The gas collection hood is correspondingly installed above the cutting head device, and the exhaust pipe is connected to the gas collection hood. The monitoring component on the drainage pipe is a dose monitor. The cutting head device includes a first tube, a second tube, and a third tube arranged sequentially from the inside out. The second tube is sleeved outside the first tube, and the third tube is sleeved outside the second tube. A first gas channel is formed inside the first tube, a second gas channel is formed between the second tube and the first tube, and a third gas channel is formed between the third tube and the second tube. Both the second gas channel and the third gas channel are annular. It includes a first intake pipe and a second intake pipe distributed around the outer periphery of the first intake pipe, the first intake pipe and the second intake pipe extending in the same direction; the first intake pipe is connected to a first gas channel, and the second intake pipe is connected to the second gas channel and a third gas channel; a plurality of second intake pipes are evenly distributed around the outer periphery of the first intake pipe with the center line of the first intake pipe as the center. Includes a connecting plate, which is used for adjacent pipe bodies, and the connecting plate has a through hole that penetrates its wall thickness; Includes a connecting ring for connecting the intake pipe and the pipe body; The outlet of the third gas channel faces away from the first tube; the outlet of the second gas channel faces towards the first tube. The cross-sectional area ratio of the second gas channel and the third gas channel is 2~3:0.6~0.8; The lower end of the second tube has a first part and a second part, the first part is inclined from top to bottom toward the first tube, and the second part is inclined from top to bottom toward the direction away from the first tube; the lower end of the third tube is inclined from top to bottom toward the direction away from the first tube; the angle between the first part of the second tube and the vertical plane is 8~12°; the angle between the second part of the second tube and the vertical plane is 12~18°; the angle between the lower end of the third tube and the vertical plane is 12~18°.

2. The underwater cutting equipment according to claim 1, characterized in that, The gas flow rate at the outlet of the second gas channel is 100~150m³. 3 / h; the gas flow rate at the outlet of the third gas channel is 30~60m³ / h. 3 / h.

3. The underwater cutting equipment according to claim 1, characterized in that, The inclination angle of the second part of the second tube is the same as the inclination angle of the lower end of the third tube.

4. The underwater cutting equipment according to claim 1, characterized in that, The drainage pipe is also equipped with a filter, a water pump, a circulation pipe, and a circulation water valve on the circulation pipe. The circulation pipe connects the cutting pool and the drainage pipe.

5. An underwater cutting method based on the underwater cutting equipment according to any one of claims 1-4, characterized in that, The process includes the following steps: forming a first gas channel, a second gas channel, and a third gas channel, wherein the second gas channel is annularly surrounding the outer periphery of the first gas channel, and the third gas channel is annularly surrounding the outer periphery of the second gas channel; Gas is introduced into the second and third gas channels to form an air cavity on the surface of the workpiece to be cut and to discharge the water in the air cavity to the outside of the air cavity; Gas is introduced into the first gas channel, and the gas in the first gas channel mixes with the gas in the second gas channel to form a cutting flame, which is used to cut the workpiece to be cut.

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