A powder granular explosive pneumatic conveying automatic charging system and automatic charging method

Abstract

The present application belongs to the technical field of powder and granular explosive pneumatic conveying equipment, and particularly relates to a powder and granular explosive pneumatic conveying automatic charging system and an automatic charging method. The automatic charging system comprises a pneumatic conveying feeding mechanism and a medicine conveying pipe. The head of the medicine conveying pipe is in communication with the pneumatic conveying feeding mechanism, and the tail of the medicine conveying pipe is in communication with a blast hole. The automatic charging system further comprises a tackifying additive mechanism. The tackifying additive mechanism comprises a tackifying additive supply tank with a material outlet, a conveying pump in communication with the material outlet of the tackifying additive supply tank at one end, and an atomizing mixer installed in the medicine conveying pipe and in communication with the conveying pump at the other end. The atomizing mixer is located downstream of the pneumatic conveying feeding mechanism in the direction of explosive airflow conveying. The present application improves the adhesion of explosive in the blast hole and significantly reduces the pneumatic charging powder return rate.

Description

Technical Field

[0001] This invention belongs to the technical field of pneumatic conveying equipment for powdered and granular explosives, specifically relating to an automatic pneumatic conveying and loading system and method for powdered and granular explosives. Background Technology

[0002] Blasting is commonly used for ore extraction and tunnel excavation in underground metal mines, and also in some underground coal mines and underground engineering projects such as tunnels and chambers. When using granular explosives such as ammonium nitrate fuel oil (AMF) and expanded ammonium nitrate (BND) explosives, the common loading method is manual loading using a pneumatic pump-type explosive charger. This pneumatic pump-type explosive charger is a pressure vessel-type pneumatic conveying device. During operation, the bulk explosive is manually poured into the container. External compressed air enters both the container body and the discharge port. The compressed air entering the container body creates static pressure above the explosive, forcing it through the discharge port into the delivery pipe. Compressed air bypasses the discharge port, pneumatically conveying the explosive along the delivery pipe. Simultaneously, the delivery pipe outlet is inserted to the bottom of the borehole, and the explosive is loaded and pulled out simultaneously to achieve coupled loading within the borehole, ensuring the blasting effect.

[0003] The main drawbacks of pneumatic conveying with a silo pump are twofold: First, granular explosives have good flowability but poor adhesion, with about 10-20% of the explosives failing to adhere effectively to the borehole and overflowing with compressed air, resulting in powder return. This affects charging efficiency, wastes explosives, and pollutes the downhole environment. Second, silo pump charging requires manual addition of explosives and manual removal of the tube, resulting in low automation and high labor intensity for workers.

[0004] In addition, pneumatically conveyed granular explosives differ from another type of explosive commonly used in underground mine blasting, namely gelatinous emulsion explosives. Emulsion explosives are pumped and conveyed, and the explosive formula can be directly adjusted to increase the viscosity of the explosive and reduce the return rate of upward-facing charges. Summary of the Invention

[0005] The purpose of this invention is to overcome the high powder return rate of pneumatic charging in existing pneumatic explosive conveying equipment, and to provide an automatic charging system and method for pneumatic conveying of powdered explosives. This invention adds a thickening additive, which is atomized and enters the charging pipe in the form of atomized droplets. The atomized droplets of the thickening additive are adsorbed and mixed with the explosive, which improves the adhesion of the explosive in the borehole and significantly reduces the powder return rate of pneumatic charging.

[0006] To achieve the above objectives, in a first aspect, the present invention provides an automatic pneumatic conveying and loading system for granular explosives, comprising a pneumatic conveying and feeding mechanism and a delivery pipe, wherein the head of the delivery pipe is connected to the pneumatic conveying and feeding mechanism, and the tail of the delivery pipe is connected to a borehole; the system further comprises a thickening additive mechanism, the thickening additive mechanism comprising:

[0007] The thickening additive feed box has a material outlet;

[0008] A delivery pump, one end of which is connected to the material outlet of the thickening additive supply box;

[0009] An atomizing mixer is installed in and connected to the delivery pipe, and its side end is connected to the other end of the delivery pump; along the direction of explosive gas flow, the atomizing mixer is located downstream of the pneumatic conveying and feeding mechanism.

[0010] In some preferred embodiments of the present invention, the atomizing mixer includes:

[0011] The housing has an airflow cavity inside, which has an airflow inlet and an airflow outlet, the airflow outlet being connected to the drug delivery tube;

[0012] The outer ring body has one end fixed to the airflow inlet end of the housing and extends in a direction away from the airflow inlet end, and its side opening near the airflow inlet end of the housing is connected to the material outlet of the thickening additive supply box.

[0013] The inner ring is fitted inside the outer ring, with a feeding gap between one end of the inner ring and the inner wall of the shell. The feeding gap is connected to the material outlet of the thickening additive feeding box. The outer wall of the other end of the inner ring is translatably connected to the outer ring and extends along the direction away from the airflow inlet end of the outer ring away from the shell. The translating connection is used to move or fix the inner ring along its axial direction. The extended end of the other end of the inner ring is connected to the drug delivery tube.

[0014] More preferably, the inner wall of the airflow inlet end of the housing is a first conical surface that is smaller inside and larger outside, and / or the outer wall of the inner ring body on the side near the airflow inlet end is a second conical surface that is wider inside and narrower outside.

[0015] More preferably, the angle α between any conical surface and the axial direction of the inner wall of the shell is 5°-20°.

[0016] More preferably, the included angle of the first conical surface provided on the inner wall of the airflow inlet end of the housing is greater than the included angle of the second conical surface provided on the outer wall of the inner ring body on the side near the airflow inlet end.

[0017] In some preferred embodiments of the present invention, an annular groove is formed on the inner wall of the outer ring body near the end of the housing, and the annular groove corresponds to and communicates with the side opening of the outer ring body.

[0018] In some preferred embodiments of the present invention, the atomizing mixer further includes a propulsion ring, which is fitted onto the outer wall of the protrusion at the other end of the inner ring body.

[0019] In some preferred embodiments of the present invention, the size of the feeding gap is 0.5-5 mm.

[0020] In some preferred embodiments of the present invention, the translational connection is a threaded connection.

[0021] In some preferred embodiments of the present invention, a sleeve groove is provided at the airflow inlet end of the housing, and the outer ring body is sleeved in the sleeve groove and fixed.

[0022] In some preferred embodiments of the present invention, the inner diameters of the shell and the inner ring are the same as the inner diameter of the drug delivery tube.

[0023] In some preferred embodiments of the present invention, the pneumatic conveying and feeding mechanism includes a feeding tank, an air compressor, an induced draft fan, a filter, a feeding pipeline, a discharging pipeline, an in-tank pressurization pipeline, a conveying air pipeline, an exhaust gas pipeline, and control valves installed on each corresponding pipeline. One end of the feeding pipeline is connected to the explosive feeding hopper, and the other end of the feeding pipeline is connected to the material inlet of the feeding tank. One end of the discharging pipeline is connected to the material outlet of the feeding tank, and the other end of the discharging pipeline is connected to the explosive conveying pipeline. One end of the in-tank pressurization pipeline is connected to the air compressor or an external compressed air source, and the other end of the in-tank pressurization pipeline is connected to the feeding tank. One end of the exhaust gas pipeline is connected to the exhaust gas outlet of the feeding tank, and the other end of the exhaust gas pipeline is connected to the filter and the induced draft fan in sequence. The conveying air pipeline is connected between and connected to the feeding pipeline and the explosive conveying pipeline.

[0024] More preferably, the sending tank includes a first sending tank and a second sending tank. The first sending tank and the second sending tank are respectively equipped with corresponding inlet pipes, outlet pipes, in-tank pressurization pipes, exhaust gas pipes and their control valves. The first sending tank and its corresponding pipes are connected in parallel with the second sending tank and its corresponding pipes.

[0025] In some preferred embodiments of the present invention, the pneumatic conveying automatic charging system for granular explosives further includes an automatic tube feeding and retraction mechanism. The automatic tube feeding and retraction mechanism includes a working arm, a drum, a tube feeder, and a rotating frame. The drum and the tube feeder are sequentially arranged on the working arm. The atomizing mixer is arranged at the charging inlet of the drum. The charging tube includes a first charging tube and a second charging tube. One end of the first charging tube is connected to the discharge pipeline, and the other end of the first charging tube is connected to the inlet of the atomizing mixer. One end of the second charging tube is connected to the airflow outlet of the atomizing mixer, and the other end of the second charging tube is wrapped around the drum and extends to be connected to the tube feeder and then extends to the borehole. The rotating frame is arranged on the working arm and connected to the tube feeder. The working arm has an automatic telescopic part.

[0026] In some preferred embodiments of the present invention, the pneumatic conveying automatic loading system for powdered explosives further includes hydraulic and electrical mechanisms, which are electrically connected to the pneumatic conveying feeding mechanism and the automatic feeding and unloading mechanism, respectively.

[0027] Secondly, the present invention provides an automatic loading method for pneumatic conveying of powdered explosives, comprising: aligning the delivery pipe with the borehole, feeding the explosives via negative pressure pneumatic conveying, then atomizing the thickening additive to obtain atomized droplets; and introducing the atomized droplets into the pneumatically conveyed explosive airflow for mixing.

[0028] Preferably, the pneumatic conveying automatic charging method for granular explosives is carried out in the pneumatic conveying automatic charging system for granular explosives described in the first aspect.

[0029] In some preferred embodiments of the present invention, the thickening additive is an aqueous solution of a viscous organic compound, the viscosity of which is below 15,000 cp, and the mass flow rate of the aqueous solution is 2%-5% of the mass flow rate of the explosive in the explosive gas stream.

[0030] In some preferred embodiments of the present invention, the mass flow rate of the explosive is 20-50 kg / min, and the flow rate of the viscous organic aqueous solution is 0.5-4.0 kg / min.

[0031] In some preferred embodiments of the present invention, the automatic loading method further includes the step of preventing explosive agglomeration: observing the explosive gas flow output from the delivery pipe, and when explosive agglomerates with a diameter exceeding a threshold value of 10-20 mm appear in the explosive gas flow, or when the thickening additives gather into water droplets or water flow, reducing the proportion of thickening additives and increasing the feeding gap between the shell and the inner ring body until the explosive agglomerates and thickening additives are eliminated.

[0032] In some preferred embodiments of the present invention, the automatic charging method further includes: synchronously pulling out the delivery tube after starting the charging process, and controlling the retraction speed v of the delivery tube from the borehole according to the following conditions to control the charge density ρ of the explosive in the borehole to be 900-1100 kg / m³. 3 :

[0033] ;

[0034] Among them, Q m For the mass flow rate of the charge;

[0035] d is the borehole diameter;

[0036] ρ is the charge density.

[0037] Beneficial effects:

[0038] The pneumatic conveying automatic charging system for granular explosives of this invention, by setting a specific structure of a thickening additive mechanism downstream of the charging pipe connected to the pneumatic conveying feeding mechanism, allows the thickening additive to be conveyed to an atomizing mixer via a pump in the thickening additive mechanism after the explosive is pneumatically fed. In the atomizing mixer, the thickening additive is atomized and enters the charging pipe in the form of atomized droplets. The atomized droplets of the thickening additive adsorb and mix with the explosive, improving the adhesion of the explosive within the borehole. This significantly reduces the return powder rate of pneumatic charging while ensuring smooth conveying, and also offers a high degree of automation. Under the same conditions, if the thickening additive mechanism is set upstream of the pneumatic conveying feeding mechanism, i.e., the thickening additive is added before pneumatic feeding, the charging pipe is prone to blockage.

[0039] In the automatic loading method provided by this invention, after the explosive airflow is formed by pneumatic conveying of the explosive, atomized droplets of a suitable proportion of thickening additive are introduced. This ensures that the thickening additive and the explosive are mixed evenly, preventing clumping and significantly reducing the return powder rate. However, because the proportion of thickening additive is low (only 2%-5%) and the granular explosive is highly hygroscopic, directly injecting the thickening additive into the silo pump (i.e., the explosive silo) will result in uneven mixing and clumping, which in turn will cause blockage of the pneumatic conveying pipe. Attached Figure Description

[0040] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of the process principle of the pneumatic conveying automatic loading system for powdered and granular explosives of the present invention.

[0042] Figure 2 This is a front view of a specific embodiment of the pneumatic conveying automatic loading system for powdered and granular explosives of the present invention;

[0043] Figure 3 yes Figure 2 Top view;

[0044] Figure 4 This is a schematic diagram of a specific embodiment of the atomizing mixer of the present invention.

[0045] Explanation of reference numerals in the attached figures

[0046] 01. Pneumatic conveying and feeding mechanism; 11A. First feeding tank; 11B. Second feeding tank; 12. Air compressor; 13. Exhaust fan; 14. Filter; 15. Feeding pipe; 16. Discharge pipe; 17. Internal pressurization pipe; 18. Conveying air pipe; 19. Exhaust air pipe; 20. External compressed air source; 02. Automatic pipe feeding and retraction mechanism; 21. Working arm; 22. Drum; 23. Pipe feeder; 24. Rotary frame; 03, thickening additive mechanism; 31, thickening additive feed box; 32, conveying pump; 33, atomizing mixer; 3301, shell; 3302, outer ring; 3303, inner ring; 3304, feeding gap; 3305, annular groove; 3306, propulsion ring; 3307, additive connection pipe; 04, explosive delivery pipe; 05, blast hole; 06, hydraulic and electrical mechanism; 07, explosive feeding hopper. Detailed Implementation

[0047] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0048] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0049] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0050] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0051] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein. The terms "optional" and "discretionary" mean that they may or may not be included (or may or may not be present).

[0052] In a first aspect, the present invention provides an automated pneumatic conveying and loading system for granular explosives, such as... Figure 1 , Figure 2 and Figure 3 As shown, it includes a pneumatic conveying and feeding mechanism 01 and a delivery pipe 04. The head of the delivery pipe 04 is connected to the pneumatic conveying and feeding mechanism 01, and the tail of the delivery pipe 04 is connected to the borehole 05. It also includes a thickening additive mechanism 03.

[0053] like Figure 1 As shown, the thickening additive mechanism 03 includes: a thickening additive supply box 31, a delivery pump 32, and an atomizing mixer 33.

[0054] The thickening additive supply box 31 has a material outlet; the conveying pump 32 has one end connected to the material outlet of the thickening additive supply box 31; the atomizing mixer 33 is installed in and connected to the delivery pipe 04, and its side end is connected to the other end of the conveying pump 32; along the explosive gas flow direction, the atomizing mixer 33 is located downstream of the pneumatic conveying feeding mechanism 01.

[0055] In some preferred embodiments of the present invention, such as Figure 4 As shown, the atomizing mixer 33 includes: a housing 3301, an outer ring 3302, and an inner ring 3303.

[0056] The housing 3301 has an airflow cavity inside, which has an airflow inlet and an airflow outlet, the airflow outlet being connected to the drug delivery tube 04. The outer ring 3302 has one end fixed (e.g., welded) to the airflow inlet of the housing 3301 and extends away from the airflow inlet, with an opening on its side near the airflow inlet of the housing 3301 that connects to the material outlet of the thickening additive supply box 31. The inner ring 3303 is fitted inside the outer ring 3302, with a feeding gap 3304 between one end and the inner wall of the housing 3301. The feeding gap 3304 is connected to the material outlet of the thickening additive feeding box 31. A portion of the outer wall of the other end of the inner ring 3303 is translatably connected to the outer ring 3302 and extends along the direction away from the airflow inlet end of the outer ring 3302 from the housing 3301. This translating connection allows the inner ring 3303 to move or be fixed along its axial direction. The extended end of the other end of the inner ring 3303 is connected to the drug delivery tube 04. The translating connection refers to the connection between the portion of the outer wall of the other end of the inner ring 3303 and the outer ring 3302, which can be translatably or fixed along the axial direction of the inner ring 3303.

[0057] In the atomizing mixer 33 with the above-mentioned preferred structure, the thickening additive increases the flow rate and further accelerates atomization and dispersion after entering the feeding gap 3304, which is more conducive to the uniform mixing between the thickening additive and the explosive particle flow. The feeding gap 3304 includes the gaps between the inner wall of the shell 3301 and the inner ring 3303 in the axial direction and perpendicular to the axial direction. Since the feeding gap 3304 is connected to the material outlet of the thickening additive feeding box 31, an atomization channel is formed between the shell 3301, the outer ring 3302, and the inner ring 3303, and the thickening additive is atomized within the atomization channel.

[0058] The opening of the outer ring 3302 of the present invention is connected to the material outlet of the thickening additive supply box 31. It can be directly connected or connected through the additive pipe 3307.

[0059] More preferably, the inner wall of the airflow inlet end of the housing 3301 is a first conical surface with a smaller inner diameter and a larger outer diameter, and / or, the outer wall of the inner ring body 3303 near the airflow inlet end is a second conical surface with a wider inner diameter and a narrower outer diameter. The first conical surface with a smaller inner diameter and a larger outer diameter refers to the inner diameter of the inner wall of the housing 3301 at the airflow inlet end being smaller inside and larger outside; it can gradually increase from the inside to the outside, or it can increase in a step-like gradient from the inside to the outside. The second conical surface with a wider inner diameter and a narrower outer diameter refers to the thickness of the outer wall of the inner ring body 3303 near the airflow inlet end being wider inside and narrower outside; it can gradually decrease from the inside to the outside, or it can decrease in a step-like gradient from the inside to the outside.

[0060] More preferably, the angle α between any conical surface and the axial direction of the inner wall of the housing 3301 is 5°-20°. Under this preferred embodiment, the appropriate angle can not only adjust the gap between the housing 3301 and the inner ring 3303, but also facilitate the rapid atomization of the thickening additive in a short period of time.

[0061] More preferably, the included angle of the first conical surface on the inner wall of the airflow inlet end of the housing 3301 is greater than the included angle of the second conical surface on the outer wall of the inner ring 3303 near the airflow inlet end. In this preferred embodiment, a wedge-shaped gap is formed between the first conical surface of the housing 3301 and the second conical surface of the inner ring 3303, which is more conducive to promoting the atomization effect.

[0062] In some preferred embodiments of the present invention, an annular groove 3305 is further formed on the inner wall of the outer ring body 3302 near the end of the shell 3301. The annular groove 3305 corresponds to and communicates with the side opening of the outer ring body 3302. In this preferred embodiment, the annular groove 3305 and the feeding gap 3304 form an accelerated mixing groove. After the thickening additive enters the accelerated mixing groove between the shell 3301, the outer ring body 3302, and the inner ring body 3303, the flow rate is increased when passing through the accelerated mixing groove, further accelerating the atomization and dispersion, which is beneficial to a more uniform mixing between the thickening additive and the explosive particle flow.

[0063] The inner diameter of the annular groove 3305 of the outer ring body 3302 of the present invention can be determined according to the flow rate of the thickening additive, so as to facilitate atomization and dispersion.

[0064] In some preferred embodiments of the present invention, the atomizing mixer 33 further includes a push ring 3306, which is fitted onto the outer wall of the protrusion at the other end of the inner ring body 3303. The push ring 3306 can adjust the threaded engagement position between the outer ring body 3302 and the inner ring body 3303, thereby adjusting the translational position of the inner ring body 3303, and thus adjusting the size of the feeding gap 3304.

[0065] In some preferred embodiments of the present invention, the size of the feeding gap 3304 is 0.5-5mm, which means that the maximum size is within the above range, which is more conducive to maximizing the atomization effect.

[0066] In some preferred embodiments of the present invention, the translational connection is a threaded connection.

[0067] In some preferred embodiments of the present invention, a sleeve groove is provided at the airflow inlet end of the housing 3301, and the outer ring 3302 is sleeved and fixed within the sleeve groove. The housing 3301 and the outer ring 3302 at the sleeve groove can be threaded or welded together.

[0068] In some preferred embodiments of the present invention, the inner diameters of the shell 3301 and the inner ring 3303 are the same as the inner diameter of the delivery pipe 04, which is more conducive to the stable delivery of explosive gas flow.

[0069] The pneumatic conveying and feeding mechanism 01 is used for the pneumatic conveying of explosives. In some preferred embodiments of the present invention, the pneumatic conveying and feeding mechanism 01 includes a feeding tank, an air compressor 12, an induced draft fan 13, a filter 14, an inlet pipe 15, an outlet pipe 16, an inlet pressurization pipe 17, a conveying air pipe 18, an exhaust gas pipe 19, and control valves installed on each corresponding pipe. The positive pressure compressed air required by the pneumatic conveying and feeding mechanism 01 is provided by the air compressor 12 (preferably a vehicle-mounted air compressor 12), or an external compressed air source 20 may be used. The conveying air pipe 18 is used to provide conveying air into the explosive delivery pipe 04.

[0070] It should be noted that the control valves installed on the respective pipelines refer to control valves installed on the feed pipeline 15, discharge pipeline 16, in-tank pressurization pipeline 17, and exhaust gas pipeline 19, such as the feed control valve installed on the feed pipeline, the gas filling control valve installed on the in-tank pressurization pipeline 17, the discharge control valve installed on the discharge pipeline 16, and the gas conveying control valve installed on the gas conveying pipeline 18. Each control valve can be, for example, an electric control valve that can automatically control the flow of materials.

[0071] Preferably, one end of the feed pipe is connected to the explosive feeding hopper 07, and the other end is connected to the material inlet of the delivery tank. One end of the discharge pipe 16 is connected to the material outlet of the delivery tank, and the other end is connected to the delivery pipe 04. One end of the pressurization pipe 17 inside the tank is connected to the air compressor 12 or an external compressed air source 20, and the other end is connected to the delivery tank. One end of the exhaust pipe 19 is connected to the exhaust outlet of the delivery tank, and the other end is connected to the filter 14 and the induced draft fan 13 in sequence. The conveying air pipe 18 is connected between the feed pipe and the delivery pipe 04. Powdered explosives are poured into the explosive feeding hopper 07 and, under the negative pressure suction generated by the air compressor 12 or the external compressed air source 20, enter the delivery tank along the feed pipe 15. The exhaust gas from the delivery tank is purified by the filter 14 and then directly discharged into the environment by the induced draft fan 13.

[0072] The delivery tank can be one or multiple tanks connected in parallel. When it is a single delivery tank, it provides intermittent delivery, suitable for shallow hole blasting. More preferably, as... Figure 1 and Figure 3As shown, the delivery tank includes a first delivery tank 11A and a second delivery tank 11B. The first delivery tank 11A and the second delivery tank 11B are respectively equipped with corresponding inlet pipes, outlet pipes 16, internal pressurization pipes 17, exhaust gas pipes 19, and their control valves. The first delivery tank 11A and its corresponding pipes are connected in parallel with the second delivery tank 11B and its corresponding pipes. In this preferred embodiment, two or more delivery tanks can achieve alternating pneumatic conveying, reducing the waiting time when feeding a single delivery tank. Continuous discharge of explosives is achieved at the outlet of the delivery pipe 04, enabling alternating continuous conveying of two / multiple tanks, suitable for medium-deep hole mining blasting.

[0073] In a preferred embodiment of the present invention, the present invention adopts negative pressure suction feeding, and uses two or more delivery tanks for alternating feeding and pneumatic conveying, thereby realizing continuous charging, improving charging efficiency, reducing labor intensity, and is suitable for medium and deep hole mining blasting with a large single charge; while configuring only one delivery tank results in lower efficiency for intermittent charging, but the charging car has a simple structure, fewer equipment, and is easy to maintain, making it suitable for shallow hole tunneling blasting with a smaller single charge.

[0074] In the alternating feeding process, for example, after the first feed control valve on the first sending tank 11A reaches the set loading amount, the first feed control valve is closed, and the second feed control valve on the second sending tank 11B is opened to add the drug. In the alternating pneumatic conveying process, for example, loading begins with activating the first discharge control valve connected to the first sending tank 11A, the conveying air control valve on the conveying air pipeline 18, and the thickening additive conveying pump 32, continuing until the first sending tank 11A is emptied. Then, the second discharge control valve on the second sending tank 11B is opened, and the first discharge control valve connected to the first sending tank 11A is closed, achieving alternating discharge from the sending tanks. During the conveying process in the second sending tank 11B, the air compressor 12 and the first feed control valve can be opened to add the drug to the first sending tank 11A; the efficiency of this addition is controlled to be greater than the pneumatic conveying loading efficiency, ensuring that the addition of the drug to the first sending tank 11A is completed before the second sending tank 11B is emptied. Among them, the pneumatic conveying loading efficiency can be, for example, 20-40 kg / min, and the loading efficiency during continuous feeding can be 30-50 kg / min.

[0075] Preferably, the sending tank is a pressure vessel type sending tank.

[0076] Preferably, the delivery tank is equipped with a drug level sensor, which is used to automatically shut off the feed control valve and the air compressor 12 when the drug level reaches a preset limit level.

[0077] The working process of the pneumatic conveying and feeding mechanism 01 described in this invention includes: before loading begins, the air compressor 12 and the feeding control valve on the feeding pipeline are turned on, creating a negative pressure suction in the explosive feeding hopper 07. Bagged explosives are moved into the explosive feeding hopper 07 and the bags are broken. Under the action of negative pressure suction, the explosives enter the dispensing tank. The exhaust gas first passes through the filter 14 along the exhaust gas pipeline 19 to remove the explosive dust carried in the exhaust gas. The clean exhaust gas is then directly discharged into the environment through the induced draft fan 13. The dispensing tank is equipped with a material level sensor. When the feeding amount reaches the preset limit level, the feeding control valve and the air compressor 12 are automatically closed sequentially. This completes the negative pressure automatic feeding process.

[0078] In some preferred embodiments of the present invention, the pneumatic conveying automatic charging system for powdered explosives further includes an automatic tube feeding and retraction mechanism 02. The automatic tube feeding and retraction mechanism 02 includes a working arm 21, a drum 22, a tube feeder 23, and a rotating frame 24. The drum 22 and the tube feeder 23 are sequentially arranged on the working arm 21. The atomizing mixer 33 is provided at the charging inlet of the drum 22. The charging tube 04 includes a first charging tube 04 and a second charging tube 04. One end of the first charging tube 04 is connected to the discharge tube. Pipeline 16 is connected, with the other end of the first delivery pipe 04 connected to the inlet of the atomizing mixer 33, and one end of the second delivery pipe 04 connected to the airflow outlet of the atomizing mixer 33. The other end of the second delivery pipe 04 is wrapped around the drum 22 and extends to the delivery pipe 23 and then to the blast hole 05. The rotating frame 24 is mounted on the working arm 21 and connected to the delivery pipe 23 to enable 360° rotation of the delivery pipe 23, allowing the outlet of the delivery pipe 23 to be aligned with the blast hole 05 at any position and angle. In this preferred embodiment, the delivery pipe 23, the working arm 21, and the drum 22 are wirelessly remotely controlled, replacing manual delivery of explosives and improving the automation level of explosive loading and blasting.

[0079] It should be noted that the tube feeder 23 is located at the end of the working arm 21. The working arm 21 has an automatic telescopic section. The working arm 21 of the present invention can have multiple degrees of freedom, such as telescopic extension, which is beneficial for aligning the outlet of the tube feeder 23 with any blast hole 05 in the roadway. The tube feeder 23 can automatically feed and retract the delivery tube 04. Its structure only needs to achieve this function and can be selected from existing technologies.

[0080] The present invention uses a speed-adjustable matching system between the drum 22 and the tube feeder 23 for winding and unwinding the drug delivery tube 04. To achieve automated control functions, those skilled in the art can also equip the device with other components. For example, the automatic tube feeding and unloading mechanism 02 may also include a wireless remote control system to control the positioning of the working arm 21 and the automatic winding and unwinding of the tube feeder 23 and the drum 22. The tube feeder 23, the drum 22, and the working arm 21 can all be hydraulically driven devices.

[0081] In some preferred embodiments of the present invention, the pneumatic conveying automatic loading system for granular explosives further includes a hydraulic and electrical mechanism 06, which is electrically connected to the pneumatic conveying feeding mechanism 01 and the automatic tube feeding / retracting mechanism 02, respectively. The hydraulic and electrical mechanism 06 is used to control the activation and regulation of the hydraulic and electrical systems. The hydraulic and electrical mechanism 06 centrally provides hydraulic power, electrical power, and control signals to other mechanisms. It utilizes an onboard programmable logic controller (PLC) to analyze and process signals collected by sensors from various mechanisms, and adopts automatic control strategies according to preset programs to achieve automated and intelligent operation of the loading vehicle.

[0082] Preferably, the pneumatic conveying automatic charging system for granular explosives further includes a mining truck chassis, with the pneumatic conveying feeding mechanism 01, the delivery pipe 04, and the automatic pipe feeding / retracting mechanism 02 all mounted on the mining truck chassis. The mining truck chassis serves as the walking mechanism, and mounting other mechanisms facilitates underground movement.

[0083] When applying this invention, preparatory work can be carried out as needed. For example, after transporting bagged explosives to the underground blasting site, the pneumatic conveying automatic charging system for granular explosives is moved to the blasting operation area and parked at a position where the working arm 21's range of motion can cover all blast holes 05. A power cable is connected to provide power to the pneumatic conveying automatic charging system for granular explosives. Whether to connect an external compressed air source 20 is determined based on the site conditions. To reduce site noise, an external compressed air source 20 is preferred. If site conditions do not allow for this, a vehicle-mounted air compressor 12 is used to provide compressed air, and a three-way valve is used as a compressed air source switching switch. This completes the site preparation work.

[0084] When the automatic pneumatic conveying and charging system for granular explosives of the present invention is in operation, the charging operation begins by opening the inflation control valve on the pressurization pipeline 17 inside the tank to establish static pressure inside the delivery tank. Then, the discharge control valve on the discharge pipeline 16 is opened, and the explosive inside the tank enters the delivery pipe 04 under static pressure. Next, the delivery gas control valve on the delivery gas pipeline 18 is opened, and the explosive, under the action of the delivery gas, flows from the delivery pipe 04 through the atomizing mixer 33 and the reel 22 into the borehole 05. The delivery pump 32 is then turned on, and a thickening additive (e.g., 2-5% of the explosive mass flow rate) is injected into the atomizing mixer 33 from the thickening additive supply box 31. The thickening additive physically mixes with the explosive during the pneumatic conveying process in the delivery pipe 04, increasing the viscosity of the granular explosive. The explosive then passes through the reel 22 and the feeder 23 into the borehole 05.

[0085] Secondly, the present invention provides an automatic loading method for pneumatic conveying of powdered explosives, comprising: aligning the delivery pipe 04 with the borehole 05, feeding the explosives via negative pressure pneumatic conveying, then atomizing the thickening additive to obtain atomized droplets; and introducing the atomized droplets into the pneumatically conveyed explosive airflow for mixing.

[0086] Preferably, the thickening additive of this invention is an aqueous solution of a viscous organic compound with a viscosity below 15,000 cp and a mass flow rate of 2%-5% of the mass flow rate of the explosive in the explosive gas stream. This invention uses a thickening additive with a specific suitable viscosity and appropriate addition ratio to balance the pneumatic transport of the explosive in the delivery pipe and its subsequent adhesion in the borehole. Excessive viscosity can cause the explosive to adhere to the inner wall of the delivery pipe, leading to blockage. Insufficient viscosity hinders the adhesion of the explosive in the borehole, causing powder return and loss of the explosive charge, which is detrimental to pneumatic detonation.

[0087] In this invention, the mass flow rate of each material can be controlled by measuring the pneumatic conveying efficiency of the explosive and adjusting the conveying rate of the conveying pump, thereby controlling the ratio of thickening additives to explosives.

[0088] Preferably, the pneumatic conveying automatic charging method for granular explosives is carried out in the pneumatic conveying automatic charging system for granular explosives described in the first aspect.

[0089] In some preferred embodiments of the present invention, the mass flow rate of the explosive is 20-50 kg / min, and the flow rate of the viscous organic aqueous solution is 0.5-4.0 kg / min.

[0090] In some preferred embodiments of the present invention, the flow rate of the thickening additive is 1-3 m / s, which is more conducive to the formation of atomized dispersion.

[0091] In some preferred embodiments of the present invention, the automatic charging method further includes a step to prevent explosive agglomeration: observing the explosive gas flow output from the delivery pipe 04, and when explosive agglomerates with a diameter exceeding a threshold range of 10-20 mm appear in the explosive gas flow, or when the thickening additive gathers into water droplets or streams, reducing the proportion of thickening additive and increasing the feeding gap 3304 between the shell 3301 and the inner ring 3303 until the explosive agglomerates and thickening additives are eliminated. In this preferred embodiment, the uniformity of mixing of the thickening additive and explosive particles is detected by visual observation, observing whether there are explosive agglomerates with a diameter exceeding the threshold range of 10-20 mm, and whether there are obvious thickening additive water droplets or streams. The above measures are taken when these phenomena occur, which can further prevent the possible blockage of the pneumatic charging pipe.

[0092] The explosive gas flow output from the delivery tube 04 described in this invention can be observed by exporting the explosive gas flow from the delivery tube 04, or by directly setting a partially transparent delivery tube 04 for observation, or by using a vertically placed plastic tube to simulate the borehole 05 and the delivery tube 04 to test and observe the thickening effect.

[0093] It should be noted that when the thickening effect is poor and the powder return rate during the loading process is high, the proportion of thickening additives can be increased or the feeding gap can be increased.

[0094] In some preferred embodiments of the present invention, the automatic charging method further includes: synchronously pulling out the delivery tube 04 after starting the charging process, and controlling the retraction speed v of the delivery tube 04 from the borehole 05 according to the following conditions to control the charge density ρ of the explosive in the borehole 05 to be 900-1100 kg / m³. 3 :

[0095] ;

[0096] Among them, Q m For the mass flow rate of the charge;

[0097] d is the diameter of borehole 05;

[0098] ρ represents the charge density. In this preferred embodiment, the explosive fills the entire borehole 05 from the bottom to achieve coupled charging. The charge density within borehole 05 is controlled within the range of 900-1100 kg / m³ by controlling the tube withdrawal speed, which facilitates precise adjustment of the blasting effect. The tube withdrawal speed is controlled by the automatic tube feeding and withdrawing mechanism 02.

[0099] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. An automatic pneumatic conveying and loading system for granular explosives, comprising a pneumatic conveying and feeding mechanism and a delivery pipe, wherein the head of the delivery pipe is connected to the pneumatic conveying and feeding mechanism, and the tail of the delivery pipe is connected to a borehole, characterized in that, It also includes a thickening additive mechanism, which includes: The thickening additive feed box has a material outlet; A delivery pump, one end of which is connected to the material outlet of the thickening additive supply box; An atomizing mixer is installed in and connected to the delivery pipe, and its side end is connected to the other end of the delivery pump; along the direction of explosive gas flow, the atomizing mixer is located downstream of the pneumatic conveying and feeding mechanism; The atomizer includes: The housing has an airflow cavity inside, which has an airflow inlet and an airflow outlet, the airflow outlet being connected to the drug delivery tube; The outer ring body has one end fixed to the airflow inlet end of the housing and extends in a direction away from the airflow inlet end, and its side opening near the airflow inlet end of the housing is connected to the material outlet of the thickening additive supply box. The inner ring is fitted inside the outer ring, with a feeding gap between one end of the inner ring and the inner wall of the shell. The feeding gap is connected to the material outlet of the thickening additive feeding box. A portion of the outer wall of the other end of the inner ring is translatably connected to the outer ring and extends along the direction away from the airflow inlet end of the outer ring away from the shell. The translating connection is used to allow the inner ring to move or be fixed along its axial direction. The extended end of the other end of the inner ring is connected to the drug delivery tube. The pneumatic conveying and feeding mechanism includes a feeding tank, an air compressor, an induced draft fan, a filter, an inlet pipe, an outlet pipe, an in-tank pressurization pipe, a conveying air pipe, an exhaust gas pipe, and control valves installed on each corresponding pipe. One end of the inlet pipe is connected to the explosive feeding hopper, and the other end is connected to the material inlet of the feeding tank. One end of the outlet pipe is connected to the material outlet of the feeding tank, and the other end is connected to the explosive conveying pipe. One end of the in-tank pressurization pipe is connected to the air compressor or an external compressed air source. The other end of the internal pressurization pipeline is connected to the delivery tank, one end of the exhaust gas pipeline is connected to the exhaust gas outlet of the delivery tank, and the other end of the exhaust gas pipeline is connected to the filter and the induced draft fan in sequence. The delivery gas pipeline is connected between the feed pipeline and the drug delivery pipeline. The delivery tank includes a first delivery tank and a second delivery tank. The first delivery tank and the second delivery tank are respectively equipped with corresponding feed pipelines, discharge pipelines, internal pressurization pipelines, exhaust gas pipelines and their control valves. The first delivery tank and its corresponding pipelines are connected in parallel with the second delivery tank and its corresponding pipelines.

2. The pneumatic conveying automatic charging system for powdered and granular explosives according to claim 1, characterized in that, The inner wall of the airflow inlet end of the housing is a first conical surface that is smaller inside and larger outside, and / or the outer wall of the inner ring body on the side near the airflow inlet end is a second conical surface that is wider inside and narrower outside.

3. The pneumatic conveying automatic charging system for powdered and granular explosives according to claim 2, characterized in that, The angle α between any conical surface and the axial direction of the inner wall of the shell is 5°-20°.

4. The pneumatic conveying automatic charging system for granular explosives according to claim 3, characterized in that, The included angle of the first conical surface on the inner wall of the airflow inlet end of the housing is greater than the included angle of the second conical surface on the outer wall of the inner ring body near the airflow inlet end.

5. The pneumatic conveying automatic charging system for powdered and granular explosives according to claim 1, characterized in that, The inner wall of the outer ring body near one end of the shell is also provided with an annular groove, which corresponds to and communicates with the side opening of the outer ring body; and / or The atomizing mixer also includes a propulsion ring, which is fitted onto the outer wall of the protrusion at the other end of the inner ring body.

6. The pneumatic conveying automatic charging system for powdered and granular explosives according to claim 1, characterized in that, The size of the feeding gap is 0.5-5mm. And / or, the translational connection is a threaded connection; And / or, the airflow inlet end of the housing is provided with a sleeve groove, and the outer ring body is sleeved in the sleeve groove and fixed; And / or, the inner diameters of the shell and the inner ring are the same as the inner diameter of the drug delivery tube.

7. The pneumatic conveying automatic charging system for powdered and granular explosives according to claim 1, characterized in that, The pneumatic conveying automatic charging system for granular explosives also includes an automatic tube feeding and retraction mechanism. This mechanism comprises a working arm, a drum, a tube feeder, and a rotating frame. The drum and tube feeder are sequentially mounted on the working arm. The atomizing mixer is located at the charging inlet of the drum. The charging tube includes a first charging tube and a second charging tube. One end of the first charging tube is connected to the discharge pipeline, and the other end is connected to the inlet of the atomizing mixer. One end of the second charging tube is connected to the airflow outlet of the atomizing mixer, and the other end wraps around the drum and extends to connect with the tube feeder before extending to the borehole. The rotating frame is mounted on the working arm and connected to the tube feeder. The working arm has an automatic telescopic section. The pneumatic conveying automatic loading system for powdered explosives also includes hydraulic and electrical mechanisms, which are electrically connected to the pneumatic conveying feeding mechanism and the automatic feeding and unloading mechanism, respectively.

8. A pneumatic conveying and automatic loading method for granular explosives, characterized in that, The automatic charging method is performed in the pneumatic conveying automatic charging system for powdered and granular explosives as described in any one of claims 1-7. The automatic charging method includes: aligning the charging pipe with the borehole, feeding the explosives using negative pressure pneumatic conveying, then atomizing the thickening additive to obtain atomized droplets; and introducing the atomized droplets into the pneumatically conveyed explosive airflow for mixing. The thickening additive is an aqueous solution of a viscous organic compound with a viscosity below 15,000 cp and a mass flow rate of 2%-5% of the mass flow rate of the explosive in the explosive gas stream.

9. The automatic loading method according to claim 8, characterized in that, The mass flow rate of the explosive is 20-50 kg / min, and the flow rate of the viscous organic aqueous solution is 0.5-4.0 kg / min; and / or The automatic loading method also includes a step to prevent explosive agglomeration: observe the explosive gas flow output from the delivery pipe, and when explosive agglomerates appear in the explosive gas flow with a diameter exceeding the threshold and the threshold range being 10-20 mm, or when the thickening additives gather into water droplets or water flow, reduce the proportion of thickening additives and increase the feeding gap between the shell and the inner ring until the explosive agglomerates and thickening additives are eliminated. and / or The automatic charging method further includes: synchronously pulling out the delivery tube after starting the charging process, and controlling the withdrawal speed v of the delivery tube from the borehole according to the following conditions to control the charge density ρ of the explosive in the borehole to be between 900-1100 kg / m³. 3 : ； Among them, Q m For the mass flow rate of the charge; d is the diameter of the borehole; ρ is the charge density.

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