Multimodal rock disintegration by thermal effect and system for performing the method

Abstract

Multimodal rock disintegration by non-contact thermal effect, spallation, melting, evaporation of a rock through a movable electric arc, arc thermal expansion and subsequent shock pressure wave allows in comparison with currently available and known technologies to drill into the rock by direct action of the electric arc and heat flows generated by the electric arc. The principle of the disintegration is based on the electric arc generation, force action to it and pressing it towards the rock intended to disintegrate, which causes heating of the rock so that a phase change and thermal disintegration of the rock occurs. Subsequently, the crushed rock is transported by a fluid streams, which are involved in stabilizing and guiding of the electric arc, from the area between the rock and the electric arc, which is the area of the rock disintegration.

Claims

1. Multimodal rock disintegration by thermal effect of an electric arc produced in an electric arc generator characterized in that the electric arc acts directly on the rock, wherein at least a part of the electric arc is pressed against the rock surface via forces caused by fluid streams, each force acting on the electric arc concurrently by a tangential component, a radial component, and an axial component due to the fluid streams being directed towards the rock being disintegrated so as to generate a vortex stream of plasma such that a part of the electric arc is spiral shaped and caused to rotate in a specified discoid area in close proximity above the surface of the rock being disintegrated so that the rock disintegrates via heat generated by the electric arc and is subsequently transported away from an area where the rock is disintegrated.

2. The multimodal rock disintegration by thermal effect according to claim 1 characterized in that at least part of the electric arc, after leaving the electric arc generator, is further shaped, moved around, and pressed onto the rock via magnetic forces, each magnetic force acting on the electric arc concurrently by a tangential component, a radial component, and an axial component.

3. The multimodal rock disintegration by thermal effect according to claim 1 characterized in that the rock is intensively heated to a temperature at which a physical process weakens the rock.

4. The multimodal rock disintegration by thermal effect according to claim 1 characterized in that the rock is intensively heated to a spallation temperature.

5. The multimodal rock disintegration by thermal effect according to claim 1 characterized in that the rock is intensively heated above a melting point of the rock.

6. The multimodal rock disintegration by thermal effect according to claim 1 characterized in that the rock is intensively heated above a boiling point of the rock such that the rock evaporates.

7. The multimodal rock disintegration by thermal effect according to claim 1 characterized in that one of the fluid streams is directed towards the rock near an axis of the vortex stream and, after impacting the rock, flows substantially radially between the disintegrated rock and the electric arc and carries the disintegrated rock away from an area between the disintegrated rock and the electric arc.

8. The multimodal rock disintegration by thermal effect according to claim 1 characterized in that a radiation component of heat flow of the arc that is heading away from the rock is redirected from a reflecting surface towards the rock being disintegrated.

9. The multimodal rock disintegration by thermal effect according to claim 1 characterized in that a first one of the fluid streams together with a second one of the fluid streams and the disintegrating rock have a stabilizing effect on the electric arc.

10. The multimodal rock disintegration by thermal effect according to claim 1 characterized in that one of the fluid streams incidents perpendicularly on the surface of the rock in a centre of an area where the electric arc acts on the rock and diverges radially from the centre towards edges of the electric arc.

11. The multimodal rock disintegration by thermal effect according to claim 1 characterized in that the electric arc acts on the rock in an area having a circular ring shape.

12. The multimodal rock disintegration by thermal effect according to claim 1 characterized in that the electric arc operates in an area having a cylindrical wall shape including an inner perimeter having a side, one of the fluid streams incidents on the electric arc from the side of the inner perimeter of the area in which the electric arc operates.

13. The multimodal rock disintegration by thermal effect according to claim 1 characterized in that the electric arc operates in an area having a cylindrical wall shape including an outer perimeter having a side, one of the fluid streams incidents on the electric arc from the side of the outer perimeter of the area in which the electric arc operates.

14. The multimodal rock disintegration by thermal effect according to claim 1 characterized in that at least one of the fluid streams presses the electric arc against the rock surface and removes the disintegrated rock from an area between the electric arc and the rock.

15. The multimodal rock disintegration by thermal effect according to claim 1 characterized in that the electric arc is embedded into the rock by pressure.

16. The multimodal rock disintegration by thermal effect according to claim 1 characterized in that the rock being disintegrated is alternately heated by the electric arc and cooled by one of the fluid streams such that the rock becomes thermally stressed.

17. The multimodal rock disintegration by thermal effect according to claim 1 characterized in that electric current in the electric arc is increased such that the electric arc expands, pushes against the rock, and concurrently pushes the disintegrated rock away from an area between the electric arc and the rock.

18. The multimodal rock disintegration by thermal effect according to claim 1 characterized in that electric current of the electric arc is increased by jumps so as to generate a pressure shockwave, which disintegrates the rock mechanically and pushes the rock away from an area where the rock is being disintegrated.

19. The multimodal rock disintegration by thermal effect according to claim 18 characterized in that one of the fluid streams enters between the rock and the electric arc and enhances the pressure shockwave on the rock being disintegrated.

20. A system for carrying out multimodal rock disintegration by thermal effect, the system comprising an electric arc generator characterized in that the electric arc generator comprises: a module configured to shape the electric arc via a vortex fluid stream; a system of tangentially oriented nozzles configured to form the vortex fluid stream; electrodes arranged so that one electrode is situated near an axis of another electrode; a module configured to guide and raise the disintegrated rock, the module containing a delimitation channel with a raising slot; the channel being configured to remove a mixture consisting of evaporated media and the disintegrated rock from an area of rock disintegration; control modules configured to regulate and modulate modes of fluid streams; and reflecting surfaces configured to guide heat flow into the area of rock disintegration.

21. The system for carrying out rock disintegration by thermal effect according to claim 20 characterized in that the module for shaping the electric arc comprises a magnetic field generator.

22. The system for carrying out rock disintegration by thermal effect according to claim 20 characterized in that the system further comprises control modules for regulation and modulation of modes of a magnetic force module.

23. The system for carrying out rock disintegration by thermal effect according to claim 20 characterized in that the reflecting surfaces for guiding the heat flow are arranged such that the heat flow is reflected and directed at the rock being disintegrated.

24. The system for carrying out rock disintegration by thermal effect according to claim 20 characterized in that the reflecting surfaces are part of one of the electrodes.

25. The system for carrying out rock disintegration by thermal effect according to claim 20 characterized in that the control modules for regulation and modulation of modes include at least one of reflective, logic and coordinating, and scanning and control elements.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) Figures show a schema of multimodal rock disintegration system by thermal effect.

(2) In FIG. 1 is shown a schematic layout of the part of the arc extending radially beyond the contours of the device.

(3) In FIG. 2 is shown an enlarged view of forces acting on the electric arc.

EXAMPLES OF CARRYING OUT THE INVENTION

Example 1

(4) The object of the invention is a technological process of non-contact rock disintegration and the system for carrying out the rock disintegration process by direct thermal action on the rock and its subsequent disintegration, melting and partial evaporation. The principle of here described preferable embodiment of the invention lies in that the rock being disintegrated is heated by planar shaped and spatially directional electric arc, forming thus a high-temperature torch, rotating along the whole perimeter, having a discoid shape with dimensions larger than the contour 10 of the device, which is pressed by force action modules against the rock being disintegrated. Forces generated in device, induced by a fluid stream shaped into vortex and by an action of a magnetic field, create a force action onto the electric art and thereby, they are, by both tangential-radial component and axially pressure component, involved in its pressing against the rock, its interaction with the rock, and provide transporting and raising of the crushed rock from the disintegration area. Since the moving electric arc has a spiral shape, its force and kinematic effect in the tangential direction is expressed, from the physical and geometric nature, by tangential-radial movement. Substantially coaxial-circular arrangement of the electrodes and the force action of the fluid flow and the magnetic field allows to generate a vortex flow of plasma at the outlet of the plasma generator device.

(5) The system implementing disintegration technological process contains the following main parts: electric arc generator; arc shaping module 100, which includes fluid and magnetic guiding and shaping components—electrodes 8, 9, discharge nozzles, magnets that actuate forces on the electric arc 1 and its shaping/formation; module for force action and pressing an electric arc against the rock and its control: discharge nozzles, magnets, regulation of system of flow and changes in the hydraulic circuit; heat flow action zone 3 of electric arc pressing against the rock and the thermal interaction with the rock; module 6 for guidance and raising of crushed rock.

(6) The device also contains other parts that complement the technology, control and intensify the process of disintegration during drilling and rock disintegration by thermal effect: control modules for controlling and modulation of modes of fluid and magnetic guidance elements; module 7 of reflecting surfaces guiding heat flow to the disintegration zone; flushing zone raising and removing crushed rock from the disintegration zone.

(7) Arc shaping module 1: an electric arc picked from an electric arc generator is further shaped, formed and guided in arc shaping module 1. Arc shaping module 1 is a chamber shape of which defines the area in which the formed arc channel is in its initiation position. It contains a series of nozzles to generate fluid streams and a magnetic generator. The action of magnetic forces and fluid flow forces subsequently shape the electric arc. Furthermore through the forces exerted on the electric arc the discharge moves and its movement delimits a discoid shape, larger than the cross-section of the device in the active region.

(8) The force action modules consist of magnets generating magnetic fields 5 and the system of nozzles which by generating fluid streams 2, 4 exert force on the electric arc during its formation and when pressing against the rock. The first and the second fluid streams by their action generate forces which in the case of first fluid stream press the electric arc and in the case of second stream carry away crushed rock.

(9) Zone 3 of heat flow action—the device working in several disintegration operating modes: The zone 3 of heat flow action is located in the lower part of the chamber just above the surface of the rock being disintegrated and it is an area of direct interactive action on the rock, i.e. a contact of the electric arc and a arc of bypassing high-temperature and dissociated gases of fluid streams. The fluid streams have dual function, namely pressing, shaping, forming by their force effect and as a plasma generating medium they are involved in the generation of plasma itself passing in the proximity of the electric arc, and thereby they create a rotating discoid plasma cloud with the contour larger than the contour of the device. During non-contact direct action of the electric arc, thermal rock disintegration leads to the disintegration of the rock. By that are generated hot gaseous mixture composed of vapours of evaporated rock and plasma generating fluid stream carrying gases, which exert forces on the electric arc. The electric arc and the flowing fluid streams with their effects, temperature ranges and thermal heating allow for multimodal operation, i.e. multiple mechanisms for rock disintegration, and thus they disintegrate the rock.

(10) The heat levels in non-contact thermal disintegration close to the rock are controlled by control modules, a control of the electric current that is supplied to the electric arc and control of corresponding force action of force carriers on the electric arc.

(11) Control modules: Various methods of rock disintegration, as well as different heat levels and temperature ranges can answer to different behaviour and properties of different rock types during their disintegration and their responses to the thermal effect. The control module changes the temperature of another supplied fluid stream in intervals as to intensify through alternate heating and cooling of rock being disintegrated at disintegration process that occurs through spallation, melting and evaporation of the rock material.

(12) A sequence of signals for generating pulse rises in the electric current feeding the electric arc is formed in control module which causes the arc's expansion. The power of the electric are increases in repeated intervals in pulses, which causes the arc to expand and by the dynamic action of the flowing medium puts pressure on the rock and at the same time pushes the melted rock away from the area between the electric arc and the rock.

(13) Reflecting surfaces module 7: The pressing electric arc itself is characterized in that the thermal energy emitted from it radiates evenly in all directions into its surroundings. That is why the heat energy radiating and routing from the rock disintegration area is reflected in heat flow reflecting surfaces module 7 and concentrated onto the surface of the rock being disintegrated. The heat flow reflecting surfaces module 7 consists of reflecting and guiding elements, which are located on the surface of the electrodes which not only guide the radiative components of the heat flow but also protect the active and exposed wall areas of the device from the heat generated by the heat flows.

(14) Module 6 for guidance and raising of crushed rock is a zone of interaction between the electric arc and the rock and is located in the area between them. Through the flushing function of the second fluid stream 4 it is directed so as to generate a steady stream on the rock surface removing evaporating rock immediately after its forming and preventing the crushed rock from shielding and from restricting the spread of the heat flow radiation components, thereby avoiding further unnecessary heating of vapourized rock near or in the area of the electric arc. The tangential and axial pressure force components act simultaneously on the electric arc, while removing and flushing out the crushed rock material in the form of vapour, melted rock, as well as disintegrated solid phase from the bottom of the borehole.

(15) The flowing mixture of crushed rock and the pressure and plasma generating fluid streams are raised to the edge of the rock being disintegrated while pushing before them vapourized rock fractions.

(16) The mixture of crushed rock, flowing gases and vapours is a mixture of expanding gases and evaporated rock mixed with drift parts of rock raised radially to the edge of the device outside the rock disintegration area, where it is under pressure gradient flushed out of the device.

Example 2

(17) Another example embodiment is a system of rock disintegration by rock melting, which operates in the same configuration, on the same principle as described in example 1, but under different temperature and power levels, preferably from 700-1800 K and the power between 3000-8000 J/cm.sup.3 on the rock being disintegrated, that is in a different operating mode. They differ in the intensity of thermal action of the electric arc on the rock in the heat flow action zone 3.

(18) During the non-contact thermal disintegration by an electric arc the rock material in a close vicinity of the rock is disintegrated by melting, which generates hot mixtures of molten rock and plasma generating, carrying fluid streams that exert force on the electric arc. In the middle range of disintegration temperatures using rock melting the interaction produces molten rock, which is carried out through the force action of another supplied fluid stream as well as expanding plasma generating medium, and which then due to mixing and cooling solidifies into fine fractions outside the zone 3 of heat flow action of the electric arc pressed on the rock.

Example 3

(19) Another example embodiment is a system of rock disintegration through spallation effect, which operates on the same principle as described in example 1, but under different temperature and power levels, preferably from 500-1200K and the power between 1000-3000 J/cm.sup.3 on the disintegrated rock, that is in a different operating mode. They differ in the intensity of thermal action of the electric arc on the rock in the heat flow action zone 3.

(20) During non-contact thermal disintegration by an electric arc the rock material in a close vicinity of the rock is disintegrated by spallation. This fragmented material, together with carrying and plasma generating fluid streams that exerts force on the electric arc, forms a hot mixture. At lower temperatures of disintegration by spallation effect the heat flow from the electric arc disintegrates the rock by flaking off solid particles due to different thermal expansion rates of different overheated and weakened sections of the rock.

Example 4

(21) Another example embodiment is a system combining thermal processes and pressure shock waves which operates in the same configuration, on the same principle as described in example 1, but operates under different temperature and power levels, that is in a different operating mode. They differ in the intensity of the thermal action of the electric arc on the rock in the zone 3 of heat flow action.

(22) During non-contact thermal disintegration by an electric arc near the rock, it is first exposed to the heat flow generated by the electric arc which can reach temperatures of up to several 10,000 Kelvin. The most important properties of disintegrated rock include mechanical strength and flexibility, reduced by the action of the heat flow. The heat flow causes intense and rapid heating of the rock. At certain temperature level, the rock's mechanical properties significantly change. This change is caused by different physical-chemical processes such as recrystallization, dehydration and the like. Subsequently they are fragmented by the action of generated pressure wave. Recrystallization deepens the resulting effect of rock disintegration by the action of generated pressure wave on the rock. Removal of fragments is provided by further pressure pulse and/or fluid flow of another supplied medium. The advantage of this mode is raising the drilling speed and the efficient use of thermal energy, which is supplied largely only into the rock, which is to be immediately removed and therefore no multiple heating and subsequent cooling occurs.

Example 5

(23) The electric arc is created by an electric arc generator and by the forces of the fluid stream and by the forces of generator's magnetic field shaped and formed into a rotational configuration. At its bottom at least part of the electric arc is, by the action of a force, pressed against the rock surface intended for disintegration. In doing so the forces induced by the first fluid stream 2 and by the magnetic field act on the electric arc simultaneously by a tangential radial component and an axial pressing component.

(24) The action of the heat flow generated by the electric arc causes direct and intense heating of the rock and thereby its disintegration. Disintegration occurs by heating the rock to a temperature level and exceeding the boiling point, with its intense vaporization. After disintegration this rock is transported outside from the area between the rock and the electric arc.

(25) The electric arc is located and moves just above the surface of the rock, wherein at least a portion is embedded into it. In this example embodiment at least part of the transferred electric arc is shaped as a spiral which rotates in a specified cylindrically shaped space and hence the rock surface on which the electric arc directly acts is shaped as a part of a spiral defined surface space, wherein the exposed and disintegrated area is larger than the projection or the contour of the device.

(26) Evaporated rock is forced out by force action of the second fluid stream that expands following the pressure gradient and pushes the crushed and evaporated rock towards the borehole periphery thereby making space for further interaction of the rotating electric arc and heat transfer into the rock by radiation.

(27) The arc's heat flow radiation component directed away from the rock is reflected in order to intensify the heat transfer into the rock being disintegrated from the reflecting surface.

(28) The first fluid stream 2 together with the second supplied fluid stream and the vaporizing rock stabilize the electric arc. The second fluid stream 4 impacts the rock perpendicularly and diverges radially from the centre towards the edges of the transferred arc.

(29) All fluid flows together with evaporated crushed material are flowing and carried out from area between the disintegrating rock and the electric arc.

Example 6

(30) In this concrete embodiment example of the invention, the rock disintegration is based on heating the rock above its melting point.

(31) The processes taking place in the initialization phase are identical to the processes described in example 5.

(32) At least part of the arc acts directly on the rock through a heat flow. This leads to an intense heating of the rock until it melts. After melting the rock, the melt itself is transported outside from area between the rock and the electric arc.

(33) The conductive channel of the electric arc is located and moves in close proximity to the surface of the rock being disintegrated. In this example embodiment at least part of the transferred electric arc has a conductive channel shaped as a spiral which rotates in a specified cylindrically shaped area. Hence the rock surface on which the electric arc directly acts is shaped as a part of a surface defined by spiral.

Example 7

(34) In this concrete embodiment example of the invention, the system of rock disintegration is based on heating the rock up to the temperature of rock spallation.

(35) The processes taking place in the initialization phase are identical to the process described in example 3, but the rock is subjected to different temperatures and power levels, that is in a different operating mode. The electric arc acts on the rock to supply enough heat in certain minimum time which is specific to each rock. Receiving more heat results in reaching a certain limit temperature and required temperature gradient in the rock. As a result of increased temperature and increased temperature gradient, the rock material fragments by spallation which generates hot mixtures consisting of fractured rock flakes and plasma generating, carrier gases of fluid streams operating by force on the electric arc. Using disintegration by spallation effect, at lower temperatures the heat flow from the electric arc disintegrates the rock by flaking off solid particles due to thermal expansion of the heated part of the rock and by weakening caused by recrystallization and different expansion rates of various types of crystals.

Example 8

(36) In this concrete embodiment example, the rock disintegration system is based on a combination of heat processes and pressure shock waves due to rock heating.

(37) The processes taking place in the initial phase are the same as in example 5. But unlike processes in example 5, the rock is subjected to different temperature and power levels, that is in a different operating mode. The electric arc acts on the rock so as to add sufficient heat to the rock and thereby to increase its temperature to a level at which some types of rock change its mechanical properties. The most important properties include mechanical strength and flexibility, which are reduced by the action of the heat flow. The heat flow causes intense and rapid heating of the rock which at certain temperature alters its mechanical properties. This change is caused by different physicochemical processes such as recrystallization, dehydration and the like. These processes are intensified by alternating the heat flow from the electric arc, which heats the rock, and the second fluid stream, which cools it down. The alternate heating and cooling thermally stresses the disintegrating rock.

(38) Subsequently, the generated pressure wave fragments it. Recrystallization and other processes that weaken the rock deepen the resulting effect of disintegration by generated pressure waves acting on the rock. The rock fragments are then removed from area between the non-crushed rock and the electric arc. Thus the entire procedure can be repeated on the next layer of the non-crushed rock. The advantages of this mode are raising the drilling speed and an efficient use of thermal energy, which is supplied largely only into the rock, which will be removed immediately, and so there is no multiple heating and subsequent cooling.

(39) The multimodality of rock disintegration consists in the fact that, depending on the disintegration method, the disintegration can take place in operating modes which run separately or in a combination according to the properties of a rock being disintegrated.

Example 9

(40) In this concrete embodiment example, the electric arc is generated by an electric arc generator, is formed between concentric cylindrical electrodes, and is then shaped and formed in an area with the shape of a cylindrical wall by the action of the fluid stream and the action of the generator's magnetic field. In the bottom part of the system for rock disintegration by direct thermal effect, the electric arc is pressed against the rock surface to be disintegrated. The forces acting on the arc move the arc simultaneously in the axial and tangential directions. The electric arc is located and moves in close proximity to the surface of the rock being disintegrated. In this example embodiment, at least part of the transferred electric arc is shaped as a spiral which rotates in a specified space with a shape of cylindrical wall and hence the rock surface on which the electric arc directly acts takes a shape of a part of the space defined by arc's movement.

(41) By the action of the heat flow generated by the electric arc a direct and intense heating of the rock occurs leading to its disintegration. Disintegration occurs by heating the rock to the temperature level and exceeding the boiling point causing an intense vaporization. The arc's heat flow radiation component directed away from the rock is reflected in order to intensify the heat transfer into the rock being disintegrated from the reflecting surfaces. After disintegration this rock is transported outside from the area situated between the surface of the rock being disintegrated and the electric arc by radial fluid flows. All fluid flows together with evaporated fragmented materials are flowing and carried out alongside the device.

REFERENCE SIGNS

(42) 100. Arc shaping module 1. Electric arc inside the active surface zone 2. Fluid stream force action module—first fluid stream 3. Zone of heat flow action 4. Fluid stream force action module—second fluid stream 5. Magnet force action module 6. Module for guidance and raising of crushed rock 7. Module of reflecting surfaces guiding the heat flows 8. Electric arc generator electrode 9. Electric arc generator electrode 10. Device contours