Device for using solid-state dry ice phase change to fracture rock, and rock-fracturing method therefor

Abstract

A device for using a solid-state dry ice phase change to fracture rock, and a rock-fracturing method therefor. The device comprises an explosive-loading vehicle (1) and an initiating apparatus (4), a clamper (2) is mounted on an explosive-loading mechanism of the explosive-loading vehicle (1), a dry ice blasting explosive-loading structure (3) is clamped at a bottom portion of the clamper (2), the dry ice blasting explosive-loading structure (3) comprises dry ice (31), a heat insulation layer (32) and an explosive (33), the heat insulation layer (32) is filled between the dry ice (31) and the explosive (33), and a filler (5) is arranged at a top portion of the dry ice blasting explosive-loading structure (3).

Description

A device and method for fracturing rocks using solid dry ice phase change. Technical Field

[0001] This invention relates to the field of rock fracturing technology, specifically to a device and method for fracturing rocks using solid dry ice phase change. Background Technology

[0002] Blasting technology utilizes the immense energy generated by explosive detonations to disrupt the surrounding environment. This destructive effect is unparalleled by other methods, playing a crucial role in railway, mining, and urban demolition, and has become the most widely used method for rock breaking and demolition. Explosive blasting primarily results from the combined action of stress waves and explosive gases. When the shock wave pressure generated by an explosive explosion exceeds the dynamic compressive strength of the rock mass, it causes the surrounding rock to pulverize. The shock wave from the explosive explosion rapidly attenuates into a stress wave, causing cracks to form in the rock mass, creating fracture zones. Subsequently, under the expansion of the explosive gases, the fractures rapidly expand under the combined action of tensile stress and the gas wedge effect, propelling the broken rock in a throwing motion.

[0003] With my country's modernization and development, blasting environments are becoming increasingly complex, and the requirements for blasting safety are also becoming more stringent. In engineering practice, it is necessary to strictly control the harmful effects of blasting. However, excessive crushing of the surrounding rock mass caused by engineering blasting, as well as the resulting strong seismic waves, air shock waves, noise, and flyrock, all consume energy that is detrimental to rock breaking. The energy released by explosives during rock explosion is transferred to the rock mass through blast stress waves and explosive gases, causing it to break. The energy actually used for rock breaking accounts for only a very small portion of the explosive's total explosive energy; most of the consumed energy is wasted, with less than 10% being used for useful work in rock breaking. Therefore, according to the requirements of blasting engineering, improving the energy utilization efficiency of explosives is a crucial factor in improving blasting effectiveness and economic benefits.

[0004] Condensed carbon dioxide exists in two forms: liquid carbon dioxide and solid carbon dioxide (solid dry ice). Liquid carbon dioxide fracturing devices generate a large amount of heat by igniting chemical substances (such as potassium perchlorate, salicylic acid, and ammonium oxalate) within a heating element. This heat is transferred to the liquid carbon dioxide. When the temperature exceeds 31°C, it rapidly vaporizes within just 40ms, creating an expansion pressure exceeding 150MPa. When this pressure exceeds the ultimate bearing capacity of the fracturing device's rupture discs, the released high-pressure gas impacts the surrounding medium, causing loosening, fracture, and ejection. However, liquid carbon dioxide phase change rock breaking suffers from high cost, difficulty in controlling fracturing and fracture formation, and unstable effects. Furthermore, it exhibits a significant energy-concentrating characteristic during rock breaking, with the rock mass directly opposite the blast outlet experiencing a greater impact. Based on these considerations, those skilled in the art have proposed a device and method for rock breaking using solid dry ice phase change fracturing. This method can increase the energy utilization efficiency of explosives, reduce the amount of explosives used, improve blasting effects, and enhance the resource utilization of carbon dioxide, thereby contributing to my country's carbon peaking and carbon neutrality strategic goals. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a device and method for rock breaking using solid dry ice phase change fracturing. Solid dry ice is used as a carbon dioxide phase change material, which is rapidly sublimated under the energy released by the explosion of explosives, generating a large amount of carbon dioxide gas. This improves the energy utilization efficiency of explosives, reduces the amount of explosives used, improves the blasting effect, and enhances the resource utilization of carbon dioxide, thereby contributing to my country's carbon peaking and carbon neutrality strategic goals.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: a device and method for rock breaking by phase change of solid dry ice, comprising a charging trolley and a detonation device, wherein a clamping device is installed on the charging mechanism of the charging trolley, and the bottom of the clamping device holds a dry ice explosive charging structure.

[0007] The dry ice blasting charge structure includes dry ice, an insulation layer and explosives, the insulation layer is filled between the dry ice and the explosives, and the top of the dry ice blasting charge structure is provided with a packing material.

[0008] In a single dry ice blasting charge structure, the mass of dry ice is less than the mass of explosive, and the work done by a unit mass of explosive is three times the mass of dry ice.

[0009] The detonation device is connected to the explosive.

[0010] Preferably, the dry ice includes, but is not limited to, different forms such as block, rod, granule, and powder. The preferred form is granular, as the porosity between dry ice particles helps increase the sublimation rate. The explosive includes, but is not limited to, emulsion explosives, water-gel explosives, ammonium nitrate explosives, aluminum-containing explosives, TNT, and RDX. The preferred explosives are emulsion explosives and water-gel explosives, both of which have good water resistance, explosive performance, and low cost. Water-gel explosives are used for water-bearing holes due to their high density and good water resistance, ensuring the explosive sinks smoothly to the bottom of the hole. Emulsion explosives are used for dry holes or boreholes with low water content due to their certain water resistance. Moreover, it has excellent explosive performance. Experimental studies have shown that emulsion explosives wrapped with a 3mm thick insulation layer can still detonate after being stored in a dry ice environment for 3 hours, providing sufficient time for on-site dry ice blasting operations. The insulation layer includes, but is not limited to, aluminum foil pearl cotton, heat insulation cotton, foam, sand, etc., with aluminum foil pearl cotton being the preferred insulation layer to reduce the impact of solid dry ice on the explosive performance of the explosive. The detonation device includes, but is not limited to, detonating cord detonators, electric detonators, electronic digital detonators, detonating cord, detonator, etc., with detonator being the preferred detonator. Combining electronic digital detonators for micro-delay detonation can increase the action time of stress waves and explosive gases, and reduce the vibration of dry ice blasting.

[0011] Preferably, the positional relationship between the dry ice, the insulation layer, and the explosive in the dry ice blasting charge structure can be a cylindrical charge structure, that is, the explosive is placed in the core of the rock borehole, the dry ice is placed on the outer periphery of the explosive, and the insulation layer is filled between the dry ice and the explosive.

[0012] Preferably, the positional relationship between the dry ice, the insulation layer, and the explosive in the dry ice blasting charge structure can be a centralized charge structure, that is, the explosive is placed at the bottom of the rock borehole, the dry ice is placed above the explosive, and the insulation layer is filled between the dry ice and the explosive.

[0013] Preferably, the positional relationship between the dry ice, the insulation layer, and the explosive in the dry ice blasting charge structure can be a layered charge structure, that is, the explosive is divided into several layers and arranged in layers in the rock mass borehole, and the weight of the explosive gradually increases from top to bottom, while the dry ice is arranged between every two layers of explosive, and the insulation layer is arranged between the dry ice and the explosive.

[0014] Preferably, the clamping device includes a detonator guide tube, a cylinder mounting bracket, two lifting cylinders, a lifting frame, a turntable, several rotating gears, several grippers, and several drive gear plates. The cylinder mounting bracket is fixed at the top of the detonator guide tube. The two lifting cylinders are respectively installed on the left and right sides of the cylinder mounting bracket. The lifting frame is fitted over the outside of the detonator guide tube and connected to the movable ends of the two lifting cylinders. The several rotating gears are arranged in a circumferential array and fixedly connected to the bottom of the lifting frame. The turntable is mounted on the outside of the detonator guide tube through bearings. The several rotating gears are arranged in a circumferential array and rotatably connected to several grooves in the turntable. The several grippers are fixedly connected to the outer walls of the several rotating gears and mesh with the rotating gears.

[0015] Preferably, the bottom of the detonator guide tube is rotatably connected to detonator limiting wheels at both the front and rear ends.

[0016] Preferably, a fixed gear plate is connected to the bottom of the lifting frame, a drive motor is installed on the outside of the detonator guide tube, a drive gear is connected to the movable end of the drive motor, and the drive gear meshes with the fixed gear plate.

[0017] Preferably, it includes the following steps:

[0018] S1. Based on the rock mass structure and the site environment of the pre-blasting area, determine the hole network parameters and drill holes to form blast holes. Use a clamping device to clamp the dry ice blasting charge structure. During clamping, two lifting cylinders drive the lifting frame to move downward, causing several drive tooth plates to drive several rotating gears and the clamps to rotate downward together, thereby clamping the dry ice blasting charge structure in several clamps. During clamping, the detonator's lead wire passes through the detonator limit wheel. After clamping, the charge trolley is placed into the blast hole.

[0019] S2. After the dry ice blasting charge structure is placed into the borehole, several grippers loosen slightly and move away from the borehole. The detonator limit wheel can prevent the detonator wire from tilting. After the bottom of the clamping device leaves the borehole, soil is poured into the borehole.

[0020] S3. After the soil layer is poured in, the two lifting cylinders drive the lifting frame to the top, causing the drive gear plate to disengage from the rotating gear. At this point, several grippers are funnel-shaped. Subsequently, the loading mechanism of the loading trolley drives the clamping device to gently tap the soil layer, compacting it. Then, the drive motor drives the drive gear to rotate, which in turn drives the fixed gear plate to rotate, thereby rotating several grippers mounted on the turntable, thus compressing the soil layer into a funnel-shaped filling material.

[0021] S4. After the packing material is compressed, the rock breaking work can be completed by using the detonation device.

[0022] Preferably, the dry ice blasting charge structure can be manufactured using ice makers, ice crushers, manual methods, or other means.

[0023] The present invention has the following technical features and beneficial effects:

[0024] This invention utilizes carbon dioxide phase change to fracture rock. The explosive energy acts directly on dry ice, causing it to sublimate rapidly, increasing the volume of the explosive gas products and forming a high-pressure gas cavity within the borehole. This reduces explosive consumption and rock mining costs. Furthermore, dry ice is safer than explosives, is not classified as a civilian explosive, and avoids the cumbersome approval process and strict supervision of public security departments. It is convenient for use in mines and can be used in complex operating environments. Compared to explosive blasting, it has higher energy utilization, effectively controlling air impact, reducing blasting vibration, and minimizing harmful effects such as dust and noise. Solid dry ice can act as a spacer structure, dispersing the charge, reducing peak pressure on the borehole wall and the surrounding rock fragmentation zone, allowing more energy to be used for rock breaking and increasing the fracture zone. Different charging methods can be used in the dry ice blasting charge structure, enabling efficient blasting of rock masses with different structures. Dry ice decouples the explosive from the borehole, reducing the rock fragmentation zone. The released energy directly acts on the solid dry ice, causing it to sublimate and rapidly release a large amount of carbon dioxide gas. This increases the gas wedge effect of the explosion products, facilitating further crack propagation and allowing more energy to be used for breaking the surrounding rock. While reducing the explosive energy, it ensures efficient rock-breaking. Under the explosive energy, the dry ice undergoes an instantaneous phase change and sublimation, rapidly expanding in volume by more than 700 times. This ensures the rock-breaking and throwing effects of dry ice blasting while reducing the amount of explosive. The blasting effect of layered dry ice blasting is better than that of concentrated blasting, mainly because it increases the number of free surfaces between dry ice and explosive, thus improving the blasting effect. It adopts a top-down loading mode of explosive + dry ice + explosive or dry ice + explosive + dry ice + explosive. Dry ice blasting can effectively reduce blasting vibration while meeting the blasting effect. In special environments, dry ice can be used to achieve vibration reduction. Attached Figure Description

[0025] Figure 1 is a schematic diagram of the structure of the present invention;

[0026] Figure 2 is a schematic diagram of the clamping device in this invention;

[0027] Figure 3 is a schematic diagram of the bottom of the clamping device in this invention;

[0028] Figure 4 shows the dry ice blasting charge structure with a centralized charge structure in this invention;

[0029] Figure 5 shows the dry ice blasting charge structure with a layered charge structure in this invention;

[0030] Figure 6 shows the dry ice blasting charge structure in the present invention, which has a cylindrical charge structure.

[0031] Figure 7 is a curve comparing the volume of the blasting funnel of the explosive and dry ice of the present invention.

[0032] Figure 8 shows the vibration measurement positions of the blasting network in this invention;

[0033] Figure 9 shows the vibration measurement curve of the explosive detonation in this invention;

[0034] Figure 10 shows the vibration measurement curve of dry ice explosion in this invention.

[0035] Among them, 1. charging trolley; 2. clamping device; 3. dry ice blasting charging structure; 4. detonation device; 5. packing material;

[0036] 21. Detonator guide tube; 22. Cylinder mounting bracket; 23. Lifting cylinder; 24. Lifting frame; 25. Turntable; 26. Rotating gear; 27. Gripper; 28. Detonator limit wheel; 29. ​​Fixed gear plate; 210. Drive gear plate; 211. Drive motor; 212. Drive gear;

[0037] 31. Dry ice; 32. Insulation layer; 33. Explosives. Detailed Implementation

[0038] 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 are within the scope of protection of the present invention. Example 1

[0039] As shown in Figures 1, 4, and 7, this embodiment provides a device and method for rock breaking using solid dry ice phase change fracturing. It includes a charging trolley 1 and a detonating device 4. A clamping device 2 is installed on the charging mechanism of the charging trolley 1. The bottom of the clamping device 2 holds a dry ice explosive charge structure 3. The dry ice explosive charge structure 3 includes dry ice 31, an insulation layer 32, and explosive 33. The insulation layer 32 fills the space between the dry ice 31 and the explosive 33. A packing material 5 is provided on the top of the dry ice explosive charge structure 3. In a single dry ice explosive charge structure 3, the mass of dry ice 31 is less than the mass of explosive 33, and the work done by a unit mass of explosive 33 is three times the mass of dry ice 31. The detonating device 4 is connected to the explosive 33. The density of liquid carbon dioxide is 1100 kg / m³, and its vaporization requires the absorption of heat q. 液 =578kJ / kg, a single 108mm diameter fracturing tube can hold 6kg of liquid carbon dioxide, and vaporization requires endothermic reaction Q. 液 =3469kJ, the ignition charge weight is 1.2kg, and the energy released by complete combustion is Q. 激 =3600kJ.Q 激Q 液， Liquid carbon dioxide can completely vaporize into a gaseous state and expand to do work, while dry ice has a density of 1560 kg / m³ and requires heat q to sublimate. 升 =574kJ / kg, density of commonly used emulsion explosives: 1200kg / m3, energy released in explosion is q. 炸 =3009kJ / kg. According to the law of conservation of energy, if the energy released by the explosive explosion is completely absorbed by dry ice, the volume ratio of dry ice to explosive is 4:1, and the mass ratio is 5.25:1. The sublimated carbon dioxide expands rapidly, generating high pressure and damaging the surrounding medium. By burying explosive 33 at a depth of 50cm from the surface of the sand, with explosive 33 masses of 90g, 100g, 110g, and 120g respectively, and comparing the explosive detonation effect with that of adding 30g of dry ice 31, the visible depth and opening diameter of the blast funnel were measured after the blast, and the volume of the blast funnel was obtained. This proves that dry ice 31 has good work-doping ability in the blast, and 30g of dry ice does work. The working capacity is equivalent to 10g of explosive, indicating that the working capacity of dry ice is about 1 / 3 the mass of explosive. Furthermore, by using solid dry ice to decouple the explosive from the borehole, it can not only reduce the rock fragmentation zone, but also allow the released energy to directly act on the solid dry ice, causing it to sublimate and rapidly release a large amount of carbon dioxide gas. This increases the gas wedge effect of the explosion products, which is conducive to further crack propagation. More energy is used for breaking the surrounding rock, reducing the explosive energy while ensuring the efficiency of rock breaking. Under the action of the explosive energy, the dry ice undergoes an instantaneous phase change and sublimation, rapidly expanding in volume by more than 700 times. This ensures the rock breaking and throwing effect of dry ice while reducing the amount of explosive.

[0040] As shown in Figures 8, 9, and 10, the blasting effects of pure explosive and dry ice + explosive charge structures are compared. The borehole diameter is 140mm, the depth is 15m, the borehole spacing is 6m, and the row spacing is 4m, totaling 13 boreholes in two rows. The charge per borehole is 192kg. Explosives are placed at the bottom of the borehole, and the upper part is filled with rock and soil. To compare the blasting effects, other parameters are kept constant, but the charge per borehole is changed. For dry ice blasting, the charge per borehole is 132kg, and the dry ice mass is 84kg. First, 84kg of explosives are placed at the bottom of the borehole, 42kg of dry ice is placed on top, then 24kg of explosives are placed on top of the dry ice, and finally 42kg of dry ice is placed on top of that. 24 kg of dry ice was placed on top of the blast hole, and then filled with soil and rock. The top and bottom of the blast hole were positioned at a distance from the detonator to ensure stable detonation of the explosives. A vibration meter was placed 100 m away from the measuring point. A drone was used to compare the rock-breaking effects of the two charge structures. Combined with the results of the shovel loading, it was found that the blasting effect of the explosive hole was comparable to that of the dry ice hole (84 kg dry ice + 132 kg explosives). Furthermore, a single hole could reduce the amount of explosives used by 60 kg. The blasting vibration velocity of the pure explosive hole was 2.867 cm / s, while that of the dry ice hole was 1.999 cm / s, representing a 30.3% reduction in vibration compared to the pure explosive hole.

[0041] As shown in Figure 4, dry ice 31 includes, but is not limited to, different forms such as block, rod, granule, and powder. The preferred form of dry ice 31 is granular, as the porosity between dry ice particles helps increase the sublimation rate. Explosive 33 includes, but is not limited to, emulsion explosives, water-gel explosives, ammonium nitrate explosives, aluminum-containing explosives, TNT, and RDX. Explosive 33 is preferably emulsion explosives or water-gel explosives, both of which have good water resistance, explosive performance, and low cost. For water-bearing holes, water-gel explosives are used because they have high density and good water resistance, ensuring the explosive sinks smoothly to the bottom of the hole. For dry holes or boreholes with low water content, emulsion explosives are used because they have a certain degree of water resistance. It is safe and has excellent explosive performance. Experimental studies have shown that emulsion explosives wrapped with a 3mm thick insulation layer can still detonate after being stored in a dry ice environment for 3 hours, which can provide sufficient time for on-site dry ice blasting operations. The insulation layer 32 includes, but is not limited to, aluminum foil pearl cotton, heat insulation cotton, foam, sand, etc., with aluminum foil pearl cotton being preferred, to reduce the impact of solid dry ice on the explosive performance of the explosive. The detonation device 4 includes, but is not limited to, detonating cord detonator, electric detonator, electronic digital detonator, detonating cord, detonator, etc., with detonator being preferred, combined with electronic digital detonator for micro-delay detonation, which can increase the action time of stress wave and explosive gas, and reduce the vibration of dry ice blasting. Example 2

[0042] As shown in Figures 4, 5, and 6, this embodiment provides another technical solution based on Embodiment 1. In the dry ice blasting charge structure 3, the positional relationship between the dry ice 31, the insulation layer 32, and the explosive 33 can be a cylindrical charge structure, where the explosive 33 is placed in the core of the rock borehole, the dry ice 31 is placed around the outer periphery of the explosive 33, and the insulation layer 32 fills the space between the dry ice 31 and the explosive 33. Alternatively, the positional relationship between the dry ice 31, the insulation layer 32, and the explosive 33 can be a concentrated charge structure, where the explosive 33 is placed at the bottom of the rock borehole, the dry ice 31 is placed above the explosive 33, and the insulation layer 32 fills the space between the dry ice 31 and the explosive 33. Finally, the positional relationship between the dry ice 31, the insulation layer 32, and the explosive 33 can be a layered charge structure, where the explosive 33 is divided into several layers and arranged layer by layer within the rock borehole. The weight of explosive 33 gradually increases from top to bottom, while dry ice 31 is placed between every two layers of explosive 33. The insulation layer 32 is placed between dry ice 321 and explosive 33. The charge structure of the dry ice blasting charge structure 3 is preferably a cylindrical charge structure, in which the explosive energy directly acts on the dry ice, causing it to sublimate rapidly. Moreover, the dry ice acts as a spacer, making the charge more dispersed, which is beneficial to improving the rock breaking and throwing effect. The blasting effect of dry ice layered charge is better than that of concentrated charge, mainly because it increases the number of free surfaces between dry ice and explosive, which can improve the blasting effect. However, from a practical point of view, considering the simplicity of on-site charge operation, the dry ice segment should not be too many. The charge mode of explosive + dry ice + explosive or dry ice + explosive + dry ice + explosive is adopted from top to bottom. While satisfying the blasting effect, dry ice blasting can effectively reduce the blasting vibration. In special environments, dry ice can be used to achieve the vibration reduction target. Example 3

[0043] As shown in Figures 2 and 3, this embodiment provides another technical solution based on Embodiments 1 and 2. The clamping device 2 includes a detonator guide tube 21, a cylinder mounting bracket 22, two lifting cylinders 23, a lifting frame 24, a turntable 25, several rotating gears 26, several grippers 27, and several drive gear plates 210. The cylinder mounting bracket 22 is fixed to the top of the detonator guide tube 21. The two lifting cylinders 23 are respectively installed on the left and right sides of the cylinder mounting bracket 22. The lifting frame 24 is sleeved on the outside of the detonator guide tube 21 and connected to the movable ends of the two lifting cylinders 23. The several rotating gears 26 are distributed in a circumferential array. The detonator is fixedly connected to the bottom of the lifting frame 24. The turntable 25 is mounted on the outside of the detonator guide tube 21 via bearings. Several rotating gears 26 are arranged in a circumferential array and rotatably connected to several slots in the turntable 25. Several grippers 27 are fixedly connected to the outer side walls of the rotating gears 26 and mesh with them. Detonator limiting wheels 28 are rotatably connected to the bottom of the detonator guide tube 21 at both the front and rear ends. A fixed gear plate 29 is connected to the bottom of the lifting frame 24. A drive motor 211 is installed on the outside of the detonator guide tube 21. A drive gear 212 is connected to the movable end of the drive motor 211. Engaging with the fixed gear plate 29, the dry ice explosive charge structure 3 is clamped by the clamping device 2. During clamping, two lifting cylinders 23 drive the lifting frame 24 to move downwards, causing several drive gear plates 210 to drive several rotating gears 26 and the clamps 27 to rotate downwards together, thereby clamping the dry ice explosive charge structure 3 in the clamps 27. During clamping, the lead wire of the detonating device 4 passes through the detonator limiting wheel 28. After clamping, it is placed into the borehole by the charging trolley 1. After the dry ice explosive charge structure 3 is placed into the borehole, the clamps 27 slightly loosen and move away from the borehole. The detonator limiting wheel 28 prevents the detonating device from being detonated. The lead wire of 4 is tilted. After the bottom of the clamping device 2 leaves the blast hole, soil is poured into the blast hole. After the soil is poured in, the two lifting cylinders 23 drive the lifting frame 24 to rise to the top, so that the drive tooth plate 210 leaves the rotating gear 26. At this time, several grippers 27 are funnel-shaped. Then the loading mechanism of the loading trolley 1 drives the clamping device 2 to gently strike the soil. After the soil is compacted, the drive motor 211 drives the drive gear 212 to rotate. The drive gear 212 drives the fixed tooth plate 29 to rotate, thereby driving several grippers 27 installed on the turntable 25 to rotate, thereby pressing the soil into a filling material 5 with a funnel-shaped top. Example 4

[0044] As shown in Figures 1 to 6, this embodiment provides another technical solution based on Embodiments 1, 2, and 3: a method for fracturing rocks using solid dry ice phase change, comprising the following steps:

[0045] S1. Based on the rock mass structure and the site environment of the pre-blasting area, determine the borehole network parameters and perform drilling to form blast holes. Use the loader 2 to load the dry ice blasting charge structure 3. When selecting the dry ice blasting charge structure 3, it is necessary to analyze the rock mass structure and site environment before making a selection. If the rock mass structure is solid but the loading time is limited, a concentrated charge dry ice blasting charge structure 3 can be selected, as its loading process is relatively simple. If the site environment is complex but the rock mass structure is relatively solid, a cylindrical charge dry ice blasting charge structure 3 can be selected. Its explosive energy directly acts on the dry ice, causing it to sublimate rapidly, and the dry ice acts as a separator, making the charge more dispersed, which is beneficial for improving rock breaking and throwing effects. If the site environment is simple but the rock mass structure is solid, a layered charge structure can be selected. The dry ice blasting charge structure 3 is mainly designed to increase the number of free surfaces between dry ice and explosives, thereby improving the blasting effect. However, considering the ease of on-site charging operations, the dry ice segments should not be too numerous. The charging mode of explosive + dry ice + explosive or dry ice + explosive + dry ice + explosive is adopted from top to bottom. While satisfying the blasting effect, dry ice blasting can effectively reduce the vibration of the blast. In special environments, dry ice can be used to achieve the vibration reduction target. During clamping, two lifting cylinders 23 drive the lifting frame 24 to move downward, so that several drive tooth plates 210 drive several rotating gears 26 and clamps 27 to rotate downward together, thereby clamping the dry ice blasting charge structure 3 in several clamps 27. During clamping, the lead wire of the detonation device 4 passes through the detonator limiting wheel 28. After clamping, it is placed into the borehole through the charging trolley 1.

[0046] S2. After the dry ice explosive charge structure 3 is placed into the borehole, several grippers 27 are slightly loosened and driven away from the borehole. The detonator limiting wheel 28 can prevent the detonator wire of the detonation device 4 from tilting. After the bottom of the clamp 2 leaves the borehole, soil is poured into the borehole.

[0047] S3. After the soil layer is poured in, the two lifting cylinders 23 drive the lifting frame 24 to rise to the top, so that the drive tooth plate 210 leaves the rotating gear 26. At this time, several grippers 27 are funnel-shaped. Then the loading mechanism of the loading trolley 1 drives the clamping device 2 to gently hit the soil layer. After the soil layer is compacted, the drive motor 211 drives the drive gear 212 to rotate. The drive gear 212 drives the fixed tooth plate 29 to rotate, thereby driving several grippers 27 installed on the turntable 25 to rotate, thereby pressing the soil layer into a filling material 5 with a funnel-shaped top.

[0048] S4. After the packing material 5 is pressed, the rock breaking work can be completed by the detonation device 4.

[0049] The dry ice 31 in the dry ice blasting charge structure 3 can be produced by means of ice maker, ice crusher, manual labor, etc. The preferred form of dry ice 31 is granular, and the pores between dry ice particles are conducive to increasing the sublimation rate of dry ice.

[0050] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for fracturing rock using solid dry ice phase change, comprising a charging trolley (1) and a detonation device (4), characterized in that, The loading mechanism of the loading trolley (1) is equipped with a clamp (2), and the bottom of the clamp (2) holds a dry ice blasting charge structure (3). The dry ice blasting charge structure (3) includes dry ice (31), insulation layer (32) and explosive (33). The insulation layer (32) is filled between the dry ice (31) and the explosive (33). The top of the dry ice blasting charge structure (3) is provided with a filler (5). In a single dry ice blasting charge structure (3), the mass of dry ice (31) is less than the mass of explosive (33), and the work done by a unit mass of explosive (33) is 3 times the mass of dry ice (31). The detonation device (4) is connected to the explosive (33).

2. The device for fracturing rock using solid dry ice phase change as described in claim 1, characterized in that, The dry ice (31) includes, but is not limited to, different forms of dry ice such as block, rod, granule, and powder. The explosive (33) includes, but is not limited to, emulsion explosive, water gel explosive, ammonium nitrate explosive, aluminum explosive, TNT and RDX. The insulation layer (32) includes, but is not limited to, aluminum foil pearl cotton, heat insulation cotton, foam, sand and soil. The detonating device (4) includes, but is not limited to, detonating cord detonator, electric detonator, electronic digital detonator, detonating cord, detonator and detonator.

3. The device for fracturing rock using solid dry ice phase change as described in claim 1, characterized in that, The positional relationship between the dry ice (31), the insulation layer (32), and the explosive (33) in the dry ice blasting charge structure (3) can be a cylindrical charge structure, in which the explosive (33) is placed in the core of the rock borehole, the dry ice (31) is placed on the outer periphery of the explosive (33), and the insulation layer (32) is filled between the dry ice (31) and the explosive (33).

4. The device for fracturing rock using solid dry ice phase change as described in claim 3, characterized in that, The positional relationship between the dry ice (31), the insulation layer (32), and the explosive (33) in the dry ice blasting charge structure (3) can be a concentrated charge structure, that is, the explosive (33) is arranged at the bottom of the rock borehole, the dry ice (31) is placed above the explosive (33), and the insulation layer (32) is filled between the dry ice (31) and the explosive (33).

5. The device for fracturing rock using solid dry ice phase change as described in claim 4, characterized in that, The positional relationship between the dry ice (31), the insulation layer (32), and the explosive (33) in the dry ice blasting charge structure (3) can be a layered charge structure, that is, the explosive (33) is divided into several layers and arranged in layers in the rock borehole, and the weight of the explosive (33) gradually increases from top to bottom, while the dry ice (31) is arranged between every two layers of explosive (33), and the insulation layer (32) is arranged between the dry ice (321) and the explosive (33).

6. The device for fracturing rock using solid dry ice phase change as described in claim 1, characterized in that, The clamping device (2) includes a detonator guide tube (21), a cylinder mounting bracket (22), two lifting cylinders (23), a lifting frame (24), a turntable (25), several rotating gears (26), several grippers (27), and several drive gear plates (210). The cylinder mounting bracket (22) is fixed at the top of the detonator guide tube (21). The two lifting cylinders (23) are respectively installed on the left and right sides of the cylinder mounting bracket (22). The lifting frame (24) is fitted onto the detonator guide tube (21). The outer side of the lifting frame (24) is connected to the movable end of the two lifting cylinders (23). The rotating gears (26) are arranged in a circular array and fixedly connected to the bottom of the lifting frame (24). The turntable (25) is installed on the outside of the detonator guide tube (21) through bearings. The rotating gears (26) are arranged in a circular array and rotatably connected to the grooves of the turntable (25). The grippers (27) are fixedly connected to the outer side wall of the rotating gears (26) and mesh with the rotating gears (26).

7. The device for fracturing rock using solid dry ice phase change as described in claim 6, characterized in that, The bottom of the detonator guide tube (21) is rotatably connected to detonator limiting wheels (28) at both the front and rear ends.

8. The device for fracturing rock using solid dry ice phase change as described in claim 7, characterized in that, The bottom of the lifting frame (24) is connected to a fixed gear plate (29), and a drive motor (211) is installed on the outside of the detonator guide tube (21). A drive gear (212) is connected to the movable end of the drive motor (211), and the drive gear (212) meshes with the fixed gear plate (29).

9. A method for fracturing rock using solid dry ice phase change according to any one of claims 1-8, characterized in that, Includes the following steps: S1. Based on the rock mass structure and the on-site environment of the pre-blasting area, determine the hole network parameters and perform drilling to form blast holes. The dry ice blasting charge structure (3) is clamped by the clamping device (2). During clamping, two lifting cylinders (23) drive the lifting frame (24) to move downward, so that several driving tooth plates (210) drive several rotating gears (26) and the clamps (27) to rotate downward together, thereby clamping the dry ice blasting charge structure (3) in several clamps (27). During clamping, the lead wire of the detonation device (4) passes through the detonator limiting wheel (28). After clamping, it is placed into the blast hole by the charging trolley (1). S2. After the dry ice blasting charge structure (3) is placed into the borehole, several grippers (27) loosen slightly and move away from the borehole. The detonator limiting wheel (28) can prevent the lead wire of the detonation device (4) from tilting. After the bottom of the clamp (2) leaves the borehole, soil is poured into the borehole. S3. After the soil layer is poured in, the two lifting cylinders (23) drive the lifting frame (24) to rise to the top, so that the drive tooth plate (210) leaves the rotating gear (26). At this time, several grippers (27) are funnel-shaped. Then the loading mechanism of the loading trolley (1) drives the clamping device (2) to gently hit the soil layer. After the soil layer is compacted, the drive motor (211) drives the drive gear (212) to rotate. The drive gear (212) drives the fixed tooth plate (29) to rotate, thereby driving several grippers (27) installed on the turntable (25) to rotate, thereby pressing the soil layer into a filling material (5) with a funnel-shaped top. S4. After the filling material (5) is pressed, the rock breaking work can be completed by the detonation device (4).

10. The device and method for rock breaking using solid dry ice phase change-induced fracturing according to claim 9, characterized in that, The dry ice blasting charge structure (3) can be made by means of ice maker, ice crusher, manual labor, etc.

Images