RU2769194C1 - Multifunctional laser module mlm (complex) - Google Patents

Abstract

FIELD: laser technology.

SUBSTANCE: invention relates to a mobile multifunctional laser complex for remote separation cutting of massive metal, concrete and combined structures, underwater cutting and elimination of the consequences of hydrocarbon pollution on water, ice, coastal and coastal surfaces. The laser complex includes one Yb fiber laser with an output power of up to 20 kW with radiation output to the transport fiber. The laser is designed with the possibility of connecting it to a laser forming single-channel telescope or a remote optical module, which are designed to fragment the cutting object with focused laser radiation in a wide range of refocusing (from 0.1 to 100 m), as well as to a sealed underwater optical module designed for underwater separation cutting. The laser forming telescope and the remote optical module are placed on pivoting devices with two-coordinate movement. A nozzle equipped with a gas-dynamic system for protecting its output optics from vapors and melt droplets is installed on the remote optical module. A sealed underwater optical module equipped with a gas-dynamic nozzle coaxial with a laser beam is mounted on a robot manipulator with three-coordinate movement.

EFFECT: versatility, which consists in the possibility of operational switching of the transport optical fiber from the forming telescope to an external optical module or an underwater optical module.

7 cl, 6 dwg

Description

FIELD OF TECHNOLOGY

The invention relates to equipment for separation cutting (including remote cutting) of massive metal, concrete and combined structures, mainly in hard-to-reach places, including under water, in the presence of hazardous factors or in the conditions of liquidation of man-made accidents.

PRIOR ART

The main method for the disposal of massive thick-walled metal structures, such as, for example, the hulls of decommissioned marine vessels, decommissioned oil and gas platforms, as well as the dismantling of construction objects, is their separating cutting into fragments with masses and dimensions convenient for their transportation to the place of disposal. The main requirements for cutting are the efficiency of work, the safety of personnel and the relatively low cost of work, which the known existing tools do not fully possess.

One of the well-known traditional thermal separation cutting methods for metal products is plasma cutting. An electric arc is ignited between the electrode and the nozzle of the apparatus, or between the electrode and the metal being cut. Gas is fed into the nozzle at a pressure of several atmospheres. When the working gas passes through an electric arc, a high-temperature plasma is formed with a temperature of several thousand degrees, which is used for cutting.

A device operating on this principle is quite effective, however, it has a number of significant drawbacks:

1) the need to use gas mixtures: cutting of low-carbon steel with a thickness of > 20 mm is carried out in nitrogen and nitrogen-hydrogen mixtures; when cutting high-alloy steels > 50 mm thick, nitrogen-oxygen mixtures are used; when cutting stainless steels, a nitrogen-hydrogen mixture is used;

2) expensive and complex plasma torch equipment;

3) relatively small thickness of the metal being cut: high-alloy steel - up to 100 mm;

4) high labor intensity and duration of equipment preparation and work;

5) increased noise due to the outflow of gas from the nozzle at transonic speeds.

6) stringent requirements for deviation from perpendicularity of the cut. Depending on the thickness of the part, the deflection angle should not exceed 10÷50°. When these limits are exceeded, there is a significant expansion of the cut and, as one of the consequences, rapid wear of consumables.

Another common thermal separation cutting method for metal products is gas cutting, the principle of which is the combustion of metal in a jet of chemically pure oxygen, followed by the removal of oxidation products from the cut zone by this jet (by blowing). With the help of combustible gas, the metal is heated to a temperature of 1100 ° C. Then, a jet of pure oxygen at a pressure of 10÷12 atm is supplied to the impact zone. in which the metal is oxidized and the subsequent slag is blown out of the impact zone.

The most popular in practice today are the following methods:

1) cutting with propane and oxygen applicable for operations with titanium alloys, low carbon and low alloy steels; if the content of carbon or an alloying component in the material exceeds 1%, it is necessary to look for other methods of oxygen efficient metal cutting; this method involves the use of other gases: methane, acetylene and some others;

2) air-arc cutting, the principle of which is to melt the metal using an electric arc, and the removal of residues is performed by an air jet; oxygen-electric arc cutting involves the supply of gas directly along the electrode; The disadvantage of this method are shallow cuts;

3) oxygen-flux cutting, a feature of which is the supply of an additional component (powder) to the working area, which ensures greater compliance of the material during cutting; the method is used to cut materials that form hard-melting oxides; oxy-flux cutting is applicable to cast iron, alloy steels, aluminum, copper and copper alloys, slagged metals and reinforced concrete.

The gas cutting method itself and devices operating on its principle have common disadvantages:

- the need to use gas mixtures;

- the method is not safe, since an explosion of the gas mixture is possible;

- a significant area is exposed to thermal effects.

Known means of mechanical separating cutting used in cutting building materials (concrete, reinforced concrete, brick, stone, etc.) using a diamond tool: diamond disc, diamond wire.

A diamond disc is a metal disc, on the cutting part of which diamond grit is deposited by spraying, held by a special binder. This allows you to significantly increase the resource of the tool, increase its productivity, accuracy and cleanliness of processing, keep the diameter of the circle unchanged during its operation.

The disadvantage of this tool is the need for frequent disc changes, as well as the fact that the large diameter of the disc does not allow cutting in hard-to-reach places. A disc of small diameter, at the same time, will not allow you to make a deep cut.

The diamond wire is a braided cable made of galvanized steel, with diamond rings - pearls - fixed at a certain distance (the distance between the individual segments is 25 mm). The rings are separated from each other by special inserts or polymer, which prevents them from moving relative to the cable. Diamond ring - a cutting tool similar to the segments of diamond discs.

The disadvantage of diamond wire is the need for frequent tool (rope) changes, as well as the following circumstance. When cutting large-sized massive products, its parts are set in motion under their own weight and tear the rope. This circumstance can lead to injury to the operating personnel.

One of the means of mechanical separation cutting of radioactive metal structures of nuclear power plants is known from patent RU 2687048, publ. 05/07/2019, Bull. No. 13.

The main disadvantage of this device is the need for frequent change of equipment - cutting tools (diamond saws, circular cutters, hydraulic shears, etc.) in hard-to-reach conditions of radiation exposure.

Known means of separation cutting based on technology LASOX (Laser ASisted Oxygen), based on the use of supersonic oxygen cutting with the support of laser radiation. A distinctive feature of the LASOX technology (Laser ASisted OXygen), developed by the British company The BOC Group Fabrication Technology Center at Morden, UK [1,2], is that CO ₂ laser radiation only heats the metal surface to a temperature of >1000°C before how a supersonic oxygen jet hits this surface, which cuts the metal due to the oxidation reaction.

The cutting complex includes the following elements with the following characteristics:

- technological cw CO ₂ laser (PRC 2.0 kW CO ₂ ) with an output power of up to 2 kW and two-coordinate positioning;

- gas-dynamic nozzle with an outlet diameter of 2.5 mm;

- high pressure oxygen supply system 6÷8 atm. and high purity to form a supersonic jet;

- the diameter of the diverging laser beam on the metal surface is 4 mm;

- the diameter of the supersonic oxygen jet coaxial with the laser beam is 3 mm;

- cutting speed - 0.3 m/min;

- thickness of the cut metal - up to 50 mm.

The disadvantages of this device include the need to use high purity oxygen, the small thickness of the cut steel sheet and a significantly lower cutting speed compared to traditional laser-oxygen cutting.

In addition, a common drawback of all the above described tools and techniques is that they are not all remote. The distance from the cutting tool to the surface of the material is a few millimeters, and diamond cutting is performed with the cutting tool in contact with the surface.

Known from patent RU 2485287, publ. 06/20/2013 Bull. No. 17 mobile laser technological complex has a sufficiently high power and allows remote separation cutting of massive metal and concrete structures at a large (up to 75 m) distance between the object of interaction from the focusing system.

However, the focusing system of this complex does not make it possible to obtain a sharp focusing of the radiation (the focal spot diameter is several millimeters), which would make it possible to achieve a more intensive removal of the melt from the region of radiation interaction with the material.

In addition, the equipment of the complex is placed in four block containers with dimensions (W × H × D) 2.34 × 2.34 × 2.34 m with a total weight of 10 tons, which complicates its transportation and limits the range of technological tasks to be solved.

From patent RU 2708442, publ. 06.12.2019 Bull. No. 34, a method for remote separation cutting of emergency metal structures and bulk equipment of offshore drilling platforms is known. The method involves placing the equipment of the laser complex on the deck of the vessel in sea block containers and the forming telescope on a turntable stabilized platform. The state of the metal structures to be separated is monitored from the board of the vessel that bypasses the emergency facility, and when the cutting result is detected, work is stopped.

However, this method and the shipborne laser complex based on it provide a solution to narrowly focused tasks and do not allow separation cutting in hard-to-reach areas of the structure.

SUMMARY OF THE INVENTION

The technical task and technical result of the proposed invention is the implementation of a wide range of technological tasks: separation cutting of metal and concrete structures at a distance of up to 100 m in the air, underwater cutting, as well as the elimination of the consequences of hydrocarbon pollution of the water surface, coastal and coastal strips, including number in arctic ice conditions.

The solution of these problems is possible with the help of the MLM laser complex (multifunctional laser module) with an output radiation power of up to 20 kW based on a Yb fiber laser and the ability to quickly switch the laser transport fiber to various focusing systems with a wide refocusing range.

The difference of this laser complex is that it

it is designed with the functions of cutting massive metal, concrete and combined structures, carrying out underwater cutting, and eliminating the consequences of hydrocarbon pollution,

contains one Yb fiber laser, a single-channel laser shaping telescope, as well as a set of focusing systems: an external optical module and a sealed external optical module for underwater cutting,

each of these focusing systems is configured to be operatively connected to a Yb fiber laser using a transport fiber.

Unlike the analogue described in the patent RU 2485287, publ. 06/20/2013 Bull. No. 17, all the equipment of this laser complex is placed in one block container with dimensions (W × H × D) of 2.3 × 2.2 × 6.0 m and a total weight of 6 tons, which greatly facilitates its loading and transportation to the place of work by any type of land, sea and air transport. Also, unlike the analogue, this laser complex includes one Yb fiber laser and a single-channel shaping telescope connected to the laser through a transport fiber 5 m long, which eliminates the need for such a complex operation as bringing three beams into one at a distance. The forming telescope of the complex is capable of focusing radiation at a distance of 20 to 100 m with a focal spot diameter ^of Ø10÷15 mm and an intensity in the spot of 10 ⁴ W/cm from the analog focusing system, is capable ^of obtaining a sharply focused beam Ø4÷ ⁵ mm at a distance ^of up to 30 m. ² ) at the same distance (up to 30 m) the intensity value in the focal spot and implement a more efficient mechanism for the removal of the melt under the action of the material vapor recoil pressure. The use of a single-channel telescope of this laser complex allows remote cutting of metal structures up to 190 mm thick, which solves most of the required tasks for remote separation cutting.

For cutting at short distances, in hard-to-reach places of the structure, the use of a remote optical module (PTO), which is part of this complex, is operatively connected to the laser through a transport fiber up to 100 m long and equipped with a gas-dynamic system for protecting the output optics, connected by a flexible hose to a cylinder with compressed air. The refocusing range of the PTO is 0.1÷3 m, and the diameter of the focal spot on the surface of the interaction object is Ø4÷5 mm, which makes it possible, with a laser output power of 20 kW, to obtain a radiation intensity in the impact zone (1÷1.5)⋅10 ⁵ W/cm ² and provides cutting metal structures up to 190 mm thick. In accordance with the invention, the removal of the melt from the zone of exposure to radiation occurs due to the recoil pressure of the vapors of the material, and the air jet of the gas-dynamic protection system prevents vapors and melt drops from entering the PTO protective glass.

The maximum cutting thickness of concrete structures is 1.5 times higher than the maximum cutting thickness of metal structures with the same energy input. This circumstance is explained by an order of magnitude lower thermal conductivity of concrete compared to steel, which makes it possible to successfully use this laser complex in the dismantling of building concrete structures.

When developing a gas-dynamic protection system, two schemes were implemented: coaxial with a laser beam and with transverse blowing of the output optics. The principle of operation of the first scheme is based on the blowing of vapors and melt splashes from the PTO protective glass in the direction along the beam. In the second scheme, a transverse supersonic air flow is organized, which prevents vapors and melt drops from settling on the surface of the PTO protective glass.

For underwater cutting, a sealed underwater optical module (POM) is used, which is quickly connected to the laser through a transport fiber up to 100 m long and equipped with a gas-dynamic nozzle coaxial with the laser beam, as well as a robotic arm and a video surveillance system. In this part, the described scheme is close to the coaxial scheme of the gas-dynamic protection system for the PTO output optics. When using POM, an air channel is organized in the aquatic environment between the nozzle and the surface of the product being cut. The design of the POM, as well as all the technological equipment, allows for separation cutting at a depth of up to 100 m.

With the help of a forming telescope or PTO, which are part of this laser complex, it is possible to eliminate emergency oil spills on water, ice, coastal and coastal surfaces. The PTO, connected to the laser through a transport optical fiber, makes it possible to obtain a diverging beam with a cross-sectional area of 3÷30 cm ² at a distance of several meters, which, with a laser output power of 20 kW, gives an intensity in the beam of 6.7⋅10 ² ÷6.7⋅10 ³ W/cm ² . Then, by moving the spot of the laser beam over the surface to be cleaned (beam scanning), oil products are burned.

When using this laser complex, the following results are achieved:

- the use of a single-channel shaping telescope, which eliminates the need for such a complex operation as bringing several beams into one at a distance;

- obtaining the intensity of radiation in the impact zone (1÷1.5)⋅10 ⁵ W/cm ² , which leads to intense boiling of the melt and its removal under the action of vapor pressure;

- remote cutting of metal structures up to 190 mm thick;

- the maximum cutting thickness of concrete structures is 1.5 times higher than the maximum cutting thickness of metal structures with the same energy input;

- carrying out underwater separation cutting at a depth of up to 100 m;

- obtaining a divergent beam with a cross-sectional area of 3÷30 cm ² and, accordingly, at a laser output power of 20 kW, the intensity in the beam is 6.7⋅10 ² ÷6.7⋅10 ³ W/cm ² , allowing laser cleaning of water, ice, coastal and coastal surfaces.

BRIEF DESCRIPTION OF THE FIGURES

The essence of the invention is illustrated by drawings, which show:

Fig. 1 - laser complex MLM (multifunctional laser module) in a transport block container;

Fig. 2 - diagram of cutting with a telescope;

Fig. 3 - scheme of cutting with the help of PTO;

Fig. 4 - diagram of the gas-dynamic protection system for the PTO output optics;

Fig. 5 - scheme of conducting underwater cutting;

Fig. 6 - scheme of liquidation of the consequences of hydrocarbon pollution.

Positions in Fig. 1÷6 mean the following:

1 - single-channel laser forming telescope;

2 - two-coordinate support-rotary device of the forming telescope (OPU);

3 - table OPU;

4 - electric convector;

5 - fire extinguisher;

6 - ventilation grill;

7 - cooling system;

8 - Yb fiber laser;

9 - operator's table;

10 - electrical panel;

11 - exhaust duct from the chiller;

12 - exhaust pipe from the heater generator;

13 - diesel heater;

14 - block container with equipment of the laser complex;

15 - laser radiation;

16 - object of interaction;

17 - transport fiber;

18 - two-coordinate turntable of a remote optical module (OPU PTO);

19 - remote optical module (PTO);

20 - nozzle gas-dynamic protection system;

21 - flexible compressed air supply hose;

22 - cylinder with compressed air;

23 - nozzle with transverse blowing of the output optics;

24 - slotted nozzle;

25, 26 - side slots;

27 - robotic arm;

28 - "arm" of the robotic arm;

29 - underwater optical module (POM);

30 - air channel between the nozzle and the surface of the product being cut;

31 - cable for monitoring and controlling the robotic arm;

32 - carrying rope-cable;

33 - manipulator power cable;

34 - cable-cable reel;

35 - surface to be cleaned (ice, water, ground).

IMPLEMENTATION OF THE INVENTION

All elements of the MLM laser complex are located in one block container (Fig. 1). The laser forming single-channel telescope 1 is installed on the OPU 2, located on the OPU table 3. An electric convector 4 is installed near the OPU table 3, and a fire extinguisher 5 is installed near the entrance door to the block container of the complex. After the entrance door, on the same side of the block container, there is a ventilation grill 6 of the cooling system 7 Yb of a fiber laser with an output power of 20 kW 8. Next to the OPU table 3, an operator’s table 9 is installed, above which a power switchboard 10 is located. also an exhaust pipe from the heater generator 12 and a diesel heater 13. 14 - a block container with the equipment of the laser complex.

To be able to conduct separation cutting at distances of 10÷100 m from the focusing system (Figure 2), as part of this complex 14, a forming single-channel telescope 7 is used, which focuses laser radiation 15 on the surface of the interaction object 16.

When cutting at distances of 0.1÷3 m from the focusing system (Fig. 3), PTO 19 is connected to the Yb fiber laser of this complex 14 through a transport fiber 17 with a length of up to 100 m, installed on the OPU PTO 18. On the front part of the PTO, a threaded connection is fixed a nozzle with a gas-dynamic protection system 20 connected by a flexible compressed air supply hose 21 to a compressed air cylinder 22. A focused laser beam 75 falls on the surface of the interaction object 16, performing separation cutting.

A scheme of gas-dynamic protection of the PTO output optics with the organization of a supersonic air flow transverse to the laser beam has been developed and implemented (Fig. 4). A slit nozzle 24 is mounted on the front part of the nozzle 23, which forms a vertically directed supersonic air flow that carries away vapors and splashes of the melt. Through the side slots 25 and 26, the PTO is focused by turning the dial and blowing the PTO protective glass before starting work, respectively.

When carrying out underwater laser cutting, a POM and a robotic arm are used, connected by cables to a real laser complex, including those located on board the ship (Fig.5 a and b): 27 - robotic arm, 28 - "arm" of the robotic arm, 29 - POM, 30 - air channel between the nozzle and the surface of the product being cut, 21 - flexible compressed air supply hose, 77 - laser transport fiber, 31 - cable for monitoring and controlling the robot-manipulator, 32 - carrying cable-cable, 33 - manipulator power cable , 16 - cut metal structure, 34 - cable-cable reel, 14 - real laser complex.

To eliminate emergency oil spills on water, ice, coastal and coastal surfaces (Fig. 6) to the Yb fiber laser of this complex 14 through the transport fiber 77 installed on the PTO control unit 18, the PTO 19 is connected. The laser radiation 75 falls on the surface to be cleaned (ice , water, ground) 35. Upon completion of the phase of self-sustaining combustion of oil products, using a two-coordinate turntable 18, a beam scan of the surface to be cleaned is performed by afterburning oil residues on it.

Claims (7)

1. A mobile multifunctional laser complex for remote separation cutting of massive metal, concrete and combined structures, underwater cutting and elimination of the consequences of hydrocarbon pollution on water, ice, coastal and coastal surfaces, containing an ytterbium (Yb) fiber laser placed in one container unit with an output laser power up to 20 kW, a single-channel laser shaping telescope and a set of remote optical focusing systems, including a remote optical module for separation cutting and a sealed remote optical module for underwater cutting, each of the mentioned remote optical focusing systems is made with the possibility of operational connection with a Yb fiber laser through a transport fiber, while the mentioned single-channel laser forming telescope is configured to provide laser radiation transmission for remote laser cutting with a focal length of 20 up to 100 m 2. The laser complex according to claim 1, in which the transport optical fiber is made up to 100 m long to transfer the laser radiation energy to a remote optical module designed for separation cutting with a focal length of 0.1 to 3 m. 3. The laser complex according to claim 1, in which the laser forming telescope and the remote optical module are mounted on turntables with two-coordinate movement. 4. The laser complex according to claim 3, in which the turntables are designed for cutting massive metal, concrete and combined structures, beam scanning of surfaces during the elimination of emergency oil spills by remote ignition, self-sustaining combustion and subsequent afterburning of oil residues by laser radiation. 5. The laser complex according to claim 1, in which a nozzle is installed on the remote optical module, equipped with a gas-dynamic system for protecting the output optics of the remote optical module from vapors and melt drops. 6. The laser complex according to claim 5, in which a slotted nozzle is mounted on the front part of the nozzle for forming a supersonic air flow transverse to the laser beam. 7. The laser complex according to claim 1, in which, to perform underwater laser separation cutting, a sealed remote optical module is installed on a robotic arm.

Images