Crushing apparatus and crushing method

Abstract

The present invention provides a crushing device and crushing method that can destroy objects with higher energy than conventional methods, as an alternative to blasting with explosives. [Solution] The crushing device comprises a heating element that generates heat using electricity supplied from a power source and has a melting point higher than the melting point of nickel-chromium alloy (nichrome), a container that seals the space containing the heating element, and a medium sealed inside the container that expands due to the thermal energy emitted from the heating element.

Description

Technical Field

[0001] The present invention relates to a crushing device and a crushing method.

Background Art

[0002] Conventionally, in civil engineering work such as tunnels, geological surveys, and mining of natural resources such as ores, blasting has been carried out to break rocks and the like using explosives and the like. Also, in the demolition work of structures constructed of concrete and the like, blasting using explosives and the like has been carried out.

[0003] By supplying electrical energy to a fine metal wire, the fine metal wire rapidly melts and evaporates, causing its volume to expand. Along with this, the object to be destroyed is destroyed or weakened by the expansion force when the destruction substance rapidly expands in volume. A method has been proposed (see Patent Document 1 below).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the above conventional technology, since the fine metal wire melts and evaporates, it cannot be denied that there is a possibility that sufficient energy for destroying the object to be destroyed cannot be input into the destruction substance. The object of the present invention is to provide a crushing device and a crushing method capable of destroying an object to be destroyed with higher energy than before in the destruction of an object to be destroyed in place of blasting with explosives and the like.

Means for Solving the Problems

[0006] The present invention is exemplified by a crushing device. This crushing device comprises a heating element that generates heat by electricity supplied from a power source and has a melting point greater than the melting point of nickel-chromium alloy (nichrome), a container that seals the space containing the heating element, and a medium sealed inside the container that expands due to the thermal energy emitted from the heating element. [Effects of the Invention]

[0007] This crushing device can destroy objects with higher energy than conventional methods, replacing blasting with explosives. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 shows an example of the application of the crushing device 1 (part 1). [Figure 2] Figure 2 shows an example of the application of the crushing device 1 (part 2). [Figure 3] Figure 3 is a diagram illustrating the configuration of a crushing device according to one embodiment. [Figure 4] Figure 4 illustrates another configuration of the blasting body in the crushing device of this embodiment. [Figure 5] Figure 5 illustrates the operation of the crushing device. [Figure 6] Figure 6 illustrates another function of the crushing device. [Modes for carrying out the invention]

[0009] A crushing apparatus 1 and a crushing method according to one embodiment of the present invention will be described below with reference to the drawings. The configuration of the following embodiments is illustrative, and the present invention is not limited to the configuration of these embodiments.

[0010] <Embodiment 1> (Application Example) Figure 1 shows an example of the application of the crushing device 1 (part 1). The crushing device 1 is used in place of blasting with explosives and other gunpowder in civil engineering works such as tunnels, geological surveys, mining of natural resources such as ore, and demolition of structures, to destroy or crush the target object. In this embodiment, the terms destruction or crushing are used to describe the action of the crushing device 1.

[0011] In Figure 1, a hole HL is drilled in the object to be destroyed, for example, a concrete structure CN, and a crushing device 1 is installed in the hole HL. The hole HL containing the crushing device 1 is closed with a clay lid CL. Power is supplied to the crushing device 1 from power supply 2 via a switch SW through lead wires L1 and L2.

[0012] In this embodiment, there are no limitations on the type of power source 2. Power source 2 may be a storage battery or commercial power supplied by a power company. Power source 2 may also be a DC power source or an AC power source. When switch SW is turned on, electrical energy is supplied from power source 2 to the crushing device 1. The crushing device 1 generates heat when electrical energy is supplied for a predetermined time (for example, within a few seconds).

[0013] The crushing device 1 holds a gas (e.g., air) and a liquid (e.g., water) inside. Due to the heat generated, the air expands, the liquid expands and then vaporizes, and the vaporized gas expands further. Through this process, the crushing device 1 ruptures and destroys the concrete structure CN. The method of application is the same as in Figure 1 when the crushing device 1 is applied to civil engineering works such as tunnels, geological surveys, and the mining of natural resources such as ores.

[0014] FIG. 2 is a diagram showing an application example (Part 2) of the crushing device 1. In FIG. 2, in tunnel construction, a plurality of holes HL are drilled and formed in a rock mass RG in which a tunnel is to be formed. The structure of each hole HL is the same as that of the hole HL in FIG. 1. The inner wall of the tunnel has, in its cross-sectional shape, vertical wall portions on both sides of the tunnel that rise from the ground, and an arch-shaped (or semi-circular) portion that further covers the upper part from the vertical wall portions. In the example of FIG. 2, a plurality of holes HL are arranged in a plurality of rows along an arch-shaped curve (see the dotted line portion).

[0015] By loading the crushing device 1 into the holes HL arranged as shown in FIG. 2 and causing it to rupture, in the rock mass RG, it is possible to effectively excavate a destruction object such as a rock mass in an arch shape and proceed with tunnel construction. When a plurality (N) of crushing devices 1 are used as shown in FIG. 1, all the crushing devices 1 may be connected in parallel to the power source 2 (see FIG. 1). Also, among the plurality (N) of crushing devices 1, a predetermined number Nx (Nx < N) of groups of crushing devices 1 may be connected in parallel to the power source 2 (see FIG. 1).

[0016] (Configuration) FIG. 3 is a diagram illustrating the configuration of the crushing device 1 according to an embodiment of the present invention. Also in the example of FIG. 3, the crushing device 1 is loaded into the hole HL of the concrete CN structure, similar to FIG. 1. However, in the example of FIG. 3, a metal pipe TU is inserted into the hole HL. Therefore, the inner wall of the hole HL is covered with the metal pipe TU. Thus, in FIG. 3, after the crushing device 1 is installed inside the pipe TU, the pipe TU is inserted into the hole HL, so that the crushing device 1 can be loaded into the hole HL of the concrete CN structure. There is no limitation on the type of metal that is the material of the pipe TU. The metal may be, for example, iron, stainless steel, aluminum, or the like.

[0017] The crushing device 1 has a container 11, an explosive body 12 housed in the internal space H1 of the container 11, a lid portion 13 that seals the internal space H1 of the container 11, and lead wires L1, L2 for supplying electrical energy to the explosive body 12. There are no limitations on the shape and material of the container 11. The shape of the outer surface of the container 11 may be, for example, cylindrical, prismatic, etc. Also, the container 11 may be a polyhedron, a sphere, etc. However, in the container 11, the wall portion that forms the internal space H1 and , by adjusting the thickness of the lid portion 13, the direction in which the destructive energy by the explosive body 12 is concentrated or the main propulsion direction of the destructive force can be controlled (see Fig. 6). The material of the container 11 is, for example, metal, resin, ceramics, clay, stone, concrete, wood, etc.

[0018] There are no limitations on the method of forming the container 11. The container 11 may be formed by drilling or excavating a bar from the outside (also referred to as the outer wall). Also, when the container 11 is made of metal, the container 11 may be cast by a mold with a convex portion. When the container 11 is made of ceramics, a shape having an internal space H1 is formed with a material such as clay and sintered. However, when the container 11 is a conductor such as metal, the contact portions between the lead wires L1, L2 and the container 11 are insulated with an insulating material so that leakage from the lead wires L1, L2 or a short circuit between the lead wires L1, L2 does not occur when power is supplied to the explosive body 12.

[0019] The lid portion 13 is, for example, in the shape of a plate cut from an axially symmetric columnar material, and has end faces at both ends in the axial direction and a side wall formed between the two end faces. In the example of Fig. 3, the axial length of the lid portion 13 is smaller than the dimension of the end face perpendicular to the axial direction of the lid portion 13. The side wall formed between the end faces at both ends in the axial direction of the lid portion 13 adheres closely to the inner wall of the space H1 and seals the space on the deeper side of the space H1. Hereinafter, the internal space sealed by the lid portion 13 is referred to as a cavity H2. The side wall of the lid portion 13 and the inner surface of the space H1 may be adhered with an adhesive. The shape of the side wall of the lid portion 13 is a shape that conforms to the shape of the inner wall of the space H1. The lid portion 13 is not limited in material as long as it can seal the space H1 and form a cavity H2 that is an internal space. The lid portion 13 is, for example, metal, resin, ceramics, clay, stone, concrete, wood, etc.

[0020] However, when the lid portion 13 is a conductor such as metal, the contact portions of the lead wires L1 and L2 with the lid portion 13 are insulated with an insulating material so that leakage from the lead wires L1 and L2 or a short circuit between the lead wires L1 and L2 does not occur when power is supplied to the blasting body 12. For example, the lid portion 13 is provided with a through-hole that connects the external space of the container 11 and the cavity H2, which is the internal space, in a state where the space H1 is sealed. Then, the through-hole may be sealed with an insulating material in a state where the lead wires L1 and L2 are passed through the through-hole. The insulating material is, for example, a resin, ceramics, an adhesive containing a resin or ceramics, or the like.

[0021] The blasting body 12 includes a heating element 121 that generates heat when an electric current flows through it after being connected to the power source 2, a gas 122 sealed in the cavity H2, and a liquid 123 sealed in the cavity H2. The heating element 121 is a rod-shaped (linear) conductive material that generates heat when an electric current flows through it. The heating element 121 extends linearly from the back surface of the lid portion 13 (the surface on the cavity H2 side) to the bottom of the cavity H2 within the cavity H2. Here, the bottom of the cavity H2 refers to the wall portion on the side opposite to the side sealed by the lid portion 13 in the cavity H2 (space H1). One end of the heating element 121 is connected to the lead wire L1 that penetrates the lid portion 13 on the back surface of the lid portion 13. The other end of the heating element 121 is connected to the lead wire L2 that penetrates the bottom of the container 11 at the bottom of the cavity H2. The hole in the lid portion 13 through which the lead wire L1 passes is sealed with an adhesive or the like. The hole at the bottom of the cavity H2 through which the lead wire L2 passes is also sealed with an adhesive or the like.

[0022] Examples of the conductive material forming the heating element 121 include nickel-chromium alloy (hereinafter simply referred to as nichrome), tungsten, molybdenum, and graphite. However, the conductive material forming the heating element 121 is not limited to the above examples. Nichrome preferably has a melting point of 1400 degrees Celsius or higher.

[0023] Within the cavity H2, at least a portion of the heating element 121 may be immersed in the liquid 123, while the other portion may be exposed to the gas 122. However, the entire heating element 121 may be immersed in the liquid 123. Both ends of the heating element 121 are connected to a power supply 2, for example, via a switch SW, by lead wires L1 and L2, respectively. Note that in Figure 3, the power supply 2 is... Although a battery symbol is shown, as mentioned in Figure 1, power source 2 is not limited to batteries and may also be commercial power supplied by a power company.

[0024] Gas 122 is, for example, air. Liquid 123 is, for example, water. Gas 122 and liquid 123 are sealed within the cavity H2 of container 11 by the lid 13 illustrated in Figure 3.

[0025] By turning on the switch SW, which is connected in series with the power supply 2 and the heating element 121 by lead wires L1 and L2, current flows from the power supply 2 to the heating element 121, and power is supplied. When power is supplied, the heating element 121 generates heat with energy determined by the supplied power and time. The heat generated by the heating element 121 causes the gas 122 in the cavity H2 to expand. In addition, the heat generated by the heating element 121 causes the liquid 123 to expand and vaporize at a temperature above its boiling point, and the vaporized gas (e.g., water vapor) expands.

[0026] The expansion of gas 122, the expansion of liquid 123, and the expansion of the gas produced when liquid 123 vaporizes cause the pressure inside the cavity H2 to rise. When the pressure inside the cavity H2 exceeds the limits of the mechanical strength or durability, which are the mechanical properties of the container 11 and the lid 13 that seals the space H1, the container 11 ruptures. The shock wave or the pressure of gas 122 and the vaporized gas accompanying the rupture of the container 11 destroys the objects to be destroyed (also called the objects to be destroyed) around the container 11.

[0027] Figure 4 illustrates another configuration of the blasting body 12 in the crushing device 1 of this embodiment. In Figure 4, the cavity H2 formed by the inner wall 11D of the container 11 and the back surface 13A of the lid 13, and the blasting body 12 inside the cavity H2 are clearly shown, while the wall and lid 13 of the container 11 are omitted.

[0028] In Figure 4, the heating element 121 is not a straight rod but is bent into a U-shape. Both ends of the heating element 121 are connected to lead wires L1 and L2 that pass through the lid 13 on the back surface 13A of the lid 13. The structure, such as sealing the holes in the lid 13 through which the lead wires L1 and L2 pass, and the action by which the blasting body 12 and container 11 destroy the surrounding objects upon power application are the same as in Figure 3.

[0029] (action) Figure 5 illustrates the operation of the crushing device 1. In Figure 5, the crushing device 1 shown in Figure 4 is illustrated. In Figure 5, the changes in state accompanying the input of power to the crushing device 1 are shown by the three crushing devices 1 illustrated on either side of arrows A1 and A2. As described above, when electrical energy is input to the heating element 121, the heating element 121 generates heat, causing the gas 122 to expand in the cavity H2, the liquid 123 to expand, and then the gas that has vaporized from the liquid 123 to expand (to the left of arrow A1).

[0030] When the pressure inside the cavity H2 exceeds the mechanical strength or durability limit of the container 11 and the lid 13 that seals the cavity H2, the container 11 ruptures (to the right of arrow A1). The shock wave or the pressure of the gas 122 and vaporized gas resulting from the rupture of the container 11 then destroys the objects surrounding the container 11.

[0031] Gases such as water vapor dissipate through cracks in the object being destroyed, and the expansion of the gas subsides (to the right of arrow A2). Also, the heating element 121 stops heating when the switch SW connecting power supply 2 and heating element 121 is turned off.

[0032] Figure 6 illustrates another operation of the crushing device 1. Figure 6 illustrates the walls (side walls 11A, bottom wall 11B) and lid 13 of the container 11 of the crushing device 1 illustrated in Figure 4. As mentioned above, the container 11 is cylindrical in one example, but it may also be prismatic. That is, in the example shown in Figure 6, the container 11 has axially symmetric side walls 11A, and the walls at both ends in the axial direction (lid 13 and bottom wall 11B) close off the space of the cavity H2.

[0033] In the example shown in Figure 6, in the crushing device 1, the thickness of the bottom wall portion 11B and the lid portion 13 at both ends in the axial direction of the wall portion surrounding the cavity H2 of the container 11 is greater than the thickness of the side wall portion 11A. Therefore, the bottom wall portion 11B and the lid portion 13 are constrained by mechanical properties, specifically mechanical strength or durability, and have higher rigidity than the side wall portion 11A. On the other hand, the side wall portion 11A has less mechanical strength or durability than the bottom wall portion 11B and the lid portion 13.

[0034] As a result, when the container 11 ruptures, the side wall 11A is destroyed before the bottom wall 11B and lid 13 are destroyed. Therefore, the expansion of the volume of the gas 122, the expansion of the volume of the liquid 123, and the expansion of the volume of the gas produced when the liquid 123 vaporizes act in the direction of the side wall of the container 11 (in the direction of the black arrow in Figure 6). For example, if the container 11 is cylindrical, the shock wave and pressure from the rupture of the container 11 act on the object to be destroyed in a direction perpendicular to the axis of the cylinder, i.e., in the direction normal to the outer surface of the side wall 11A (in the direction of the black arrow in Figure 6). Note that in Figure 6, the black arrows are illustrated in two directions, but if the container 11 is cylindrical, for example, the shock wave and pressure act in all directions perpendicular to the axis of the cylinder. Note that the crushing device 1 of the present invention is not limited to the configuration in Figure 6.

[0035] When destroying an object using the crushing device 1, three modes (types) of destruction can be assumed. The first mode of destruction is detonation. Detonation is similar to, for example, the mode of destruction by explosives. Detonation occurs when the energy for destruction is supplied to the blasting body 12 within approximately 0.17 microseconds.

[0036] The second mode of destruction is static destruction. Unlike destruction by explosives, static destruction occurs over a time range of 1 minute to 24 hours or more. That is, static destruction occurs when the energy for destruction can be supplied to the blasting body 12 over a time range of 1 minute to 24 hours or more. Compared to detonation, static destruction can destroy the target object in a more stable manner.

[0037] The third mode of destruction is an intermediate mode between detonation and static destruction. Destruction in this intermediate mode occurs in a time range of approximately 0.17 microseconds to about 1 minute. In other words, destruction in this intermediate mode occurs when the energy necessary for destruction is supplied to the blasting body 12 in a time range of approximately 0.17 microseconds to about 1 minute. Destruction in this intermediate mode can also be called dynamic destruction because the destruction progresses faster than static destruction. It is assumed that the time ranges for each of the above modes of destruction will vary depending on the volume of the container 11.

[0038] (Effects of the embodiment) As described above, the crushing device 1 has a heating element 121 that generates heat from electricity supplied from a power source 2 and has a melting point higher than the melting point of nickel-chromium alloy, and a container 11 that seals the cavity H2 which is the space containing the heating element 121. The cavity H2 of the container 11 is sealed by a lid 13. The crushing device 1 is also equipped with a gas 122 (e.g., air) and a liquid 123 (e.g., water) as a medium that is sealed inside the cavity H2 of the container 11 and expands due to the thermal energy emitted from the heating element 121. Therefore, in the crushing device 1, the heating element 121 generates heat from electricity supplied from a power source 2, the gas 122 expands inside the cavity H2, the liquid 123 expands, and then the gas that has vaporized from the liquid 123 expands, causing the container 11 to rupture. As a result, the crushing device 1 can produce an effect similar to blasting and destroy the target object without using explosives or being subject to regulations on the storage and management of explosives.

[0039] Furthermore, as described above, the crushing device 1 contains water and air as expanding media. Therefore, the crushing device 1 can effectively expand the medium with the heating element 121 and destroy the object to be destroyed.

[0040] Furthermore, examples of materials for the heating element 121 include nichrome, tungsten, molybdenum, and graphite. Nichrome generally has a melting point of 1400 degrees Celsius or higher. Tungsten has a melting point of 3420 degrees Celsius or higher, molybdenum has a melting point of 2600 degrees Celsius or higher, and graphite has a melting point of 3500 degrees Celsius or higher. Therefore, in the crushing device 1, power can be supplied while the heating element 121 is not melting, allowing for continuous high energy input, effectively expanding the medium, and destroying the object to be destroyed.

[0041] Furthermore, as described above, the container 11 is, for example, cylindrical or prismatic and has axially symmetrical side walls. It is possible to make the thickness of the axially positioned wall portion (lid portion 13 and bottom wall portion 11B) that closes the cavity H2 containing the medium thicker than the thickness of the side wall portion 11A. Therefore, as illustrated in Figure 6, the shock wave and pressure caused by the rupture of the container 11 can act on the object to be destroyed in the direction normal to the outer surface of the side wall portion 11A perpendicular to the axis of the container 11.

[0042] It should be noted that the shape of the container 11, which is subjected to shock waves and pressure in a specific direction, is not limited to cylindrical or prismatic shapes. For example, even if the container 11 is polyhedral or spherical, the same effect as in Figure 6 can be obtained by adjusting the thickness of the walls forming the cavity H2 inside the container 11 in a specific direction. For example, when the container 11 is used in a state where it is placed surrounded by an object to be destroyed, the same effect as in Figure 6 can be obtained by relatively increasing the thickness of the walls located in the vertical direction and relatively decreasing the thickness of the walls located closer to the horizontal plane.

[0043] <Variation> In the above embodiment, the cavity H2 is sealed with a gas 122 such as air and a liquid 123 such as water as a medium. In addition to this configuration, the gas 122 may contain, for example, a hydrocarbon gas. Examples of hydrocarbon gases include paraffinic hydrocarbons (CnH2n+2) such as methane (CH4), ethane (C2H6), propane (C3H8), and butane (C4H10). Examples of hydrocarbon gases include olefinic hydrocarbons (CnH2n) such as ethylene (C2H4), propylene (C3H6), and butylene (C4H8). Furthermore, the liquid 123 may contain hydrocarbons such as liquid paraffin and kerosene. Moreover, the liquid 123 may contain an alcohol. Examples of alcohols include methanol, ethanol, and propanol.

[0044] In this case, the crushing device 1 may have an ignition device (also called an ignition unit) for igniting the hydrocarbon gas. The ignition device may, for example, ignite the hydrocarbon gas in conjunction with the destruction of the container 11. The ignition device includes, for example, an ignition circuit including an ignition coil that boosts the voltage from the power supply 2 and outputs a high-voltage current, and a spark plug. The spark plug is installed in the cavity H2 and generates a spark between the high-voltage electrode and the ground electrode by the high-voltage current output from the ignition circuit, thereby igniting the hydrocarbon gas.

[0045] It is desirable that the timing of the ignition device's ignition of the hydrocarbon gas by the spark plug be synchronized with the rupture of the container 11. Therefore, the timing of the ignition device's ignition of the hydrocarbon gas by the spark plug can be controlled, for example, by the elapsed time after power is supplied from the power source 2 to the heating element 121. This elapsed time can be determined experimentally and empirically by measuring the time from the supply of power from the power source 2 to the heating element 121 until the container 11 is destroyed.

[0046] However, a pressure sensor is installed in the cavity H2 inside the container 11, and the pressure sensor detects The ignition system may be controlled to ignite the hydrocarbon gas with a spark plug when the air pressure inside the cavity H2 reaches a predetermined limit. Such control can be achieved by inputting the output signal of a comparator, which compares the output value of a pressure sensor with a predetermined limit, to the ignition system and activating the spark plug.

[0047] Alternatively, a strain sensor may be provided on the side wall portion 11A inside the container 11, and the ignition device may be controlled to ignite the hydrocarbon gas with a spark plug when the strain of the side wall portion 11A detected by the strain sensor reaches a predetermined limit value. Such control can be implemented by inputting the output signal of a comparator, which compares the output value of the strain sensor with a predetermined limit value, to the ignition device and activating the spark plug.

[0048] With this configuration, the crushing device 1 can destroy the object to be destroyed by adding shock waves and pressure from the ignition and explosion of hydrocarbon gas, in addition to the expansion of air and water described in the embodiment. [Explanation of symbols]

[0049] 1. Crushing device 2 Power supply 11 Container 11A Side wall part 11B Bottom wall 12 blasting bodies 13 Lid 121 Heating element 122 Gases 123 Liquid

Claims

1. A heating element that generates heat through electricity supplied from a power source and has a melting point higher than the melting point of nickel-chromium alloy (nichrome), A container that seals the space containing the heating element, A crushing device comprising a medium sealed within the container and which expands due to thermal energy emitted from the heating element.

2. The crushing apparatus according to claim 1, wherein the medium comprises water or air.

3. The crushing apparatus according to claim 1, wherein the heating element is one of nichrome, tungsten, molybdenum, and graphite.

4. The crushing device according to claim 1, wherein the container has axially symmetric side walls and the space is closed by the walls at both ends in the axial direction, and the thickness of the walls at both ends in the axial direction is greater than the thickness of the side walls.

5. The crushing apparatus according to claim 1, wherein the medium comprises a hydrocarbon gas.

6. The crushing apparatus according to claim 5, further comprising an ignition unit for igniting the hydrocarbon gas.

7. The heating element is heated by electricity. A medium sealed within a container that closes off the space containing the heating element is expanded by the thermal energy emitted from the heating element. A crushing method in which the container is ruptured by the expanded medium, thereby crushing an object to be destroyed outside the container.

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