An electrically heated wire ignition device and method for igniting a single grain of an energetic material in a sealed pressurized environment

Abstract

The application provides an ignition device and method for single particle of energetic material in a sealed and pressurized environment, which comprises a shell, a pressurized sealing flange and a sealing flange, the shell, the pressurized sealing flange and the sealing flange are connected to form a pressurized and sealed combustion chamber, and a heating ignition assembly is arranged in the pressurized and sealed combustion chamber; the heating ignition assembly comprises a glass slide, and fixing grooves for fixing electric heating wires are arranged on the two opposite side walls of the glass slide, the electric heating wires can be connected with a conductive column extending into the pressurized and sealed combustion chamber, and the conductive column is detachably connected with an external power source arranged outside the shell; a pneumatic quick connector is arranged on the pressurized sealing flange, and the pneumatic quick connector can be connected with a pressurizing device arranged outside the shell, the method can provide a high-temperature and high-pressure single particle combustion environment, more flexibly realize the ignition and combustion imaging of the single particle of energetic material, and effectively realize the non-interference test of single particle micro-combustion under a high-temperature and high-pressure environment.

Description

Technical Field

[0001] This invention belongs to the field of single-particle combustion technology of energetic materials, specifically relating to a device and method for igniting single-particle energetic materials in a closed pressurized environment with an electric heating wire. Background Technology

[0002] Single-particle combustion technology has become a research hotspot in the field of solid combustion due to its ability to clearly reveal the kinetic evolution characteristics of single-particle fuels at each stage of combustion, providing a comprehensive understanding of the heat and mass transfer and chemical reaction kinetics of the fuel. Currently, ignition and combustion technologies based on laser ignition and planar flame burners have been widely applied to the study of the combustion characteristics of single particles of conventional solid fuels such as pulverized coal, biomass, and highly reactive metal materials. However, single-particle ignition and combustion methods for high-energy-density energetic materials such as RDX, HMX, and CL-20 are rarely reported domestically or internationally. This is because energetic materials possess characteristics such as regular crystal shapes, violent ignition and combustion reactions, metastable lattice states, and high material hazard. Conventional high-energy lasers or xenon lamps are affected by energy dissipation caused by the crystal structure of the energetic material particles, making it difficult to ensure effective transfer of radiated energy to the single particles and their ignition.

[0003] The existing micron-scale metal particle ignition and combustion test device creates a metal particle ignition and combustion environment through a planar flame furnace to achieve highly discrete metal particles and ignition and combustion. However, this device has high requirements for the control of the planar flame furnace, and the dynamic carry-over flow makes it difficult to achieve a pressurized environment for highly discrete metal particles.

[0004] Existing technologies also include sample stages suitable for laser ignition of single energetic material particles, comprising a glass slide with micropores of a certain depth arranged on the slide, the diameter of which matches the diameter of the single particle sample. This invention can effectively confine the single particle sample, preventing the energetic material particle from shifting position due to decomposition and gas release under the action of a laser beam. However, this device uses laser ignition to ignite the single particle, which cannot guarantee effective ignition of single particles such as RDX, HMX, CL-20, and aluminum powder, which have a dissipative effect on radiant energy.

[0005] Therefore, considering the effective absorption of energy by a single particle and the requirements of a pressurized environment, it is urgent to develop a device and method for igniting a single particle of energetic material under closed pressurized environment with an electric heating wire. Summary of the Invention

[0006] In view of the defects and deficiencies of the existing technology, the purpose of this invention is to provide a heating wire ignition device and method for a single particle of energetic material under closed pressurized environment, so as to solve the technical problems that the existing single particle ignition devices for energetic materials are unable to meet the requirements of pressurized combustion environment for highly discrete particles and the single particle ignition requirements where radiant energy has a dissipative effect.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] A single-particle closed pressurized environment electric heating wire ignition device for energetic materials includes a shell with open front and rear ends, a pressurized sealing flange that can be detachably and sealingly connected to the front end of the shell, and a sealing flange that can be detachably and sealingly connected to the rear end of the shell. The shell, the pressurized sealing flange and the sealing flange are sealed together to form a pressurized closed combustion chamber. A heating and ignition assembly is provided in the pressurized closed combustion chamber.

[0009] The heating and ignition assembly includes a glass slide, on which two opposite sidewalls are provided fixing grooves for fixing a heating wire. The heating wire can be connected to a conductive post extending into the pressurized and sealed combustion chamber. The conductive post is detachably connected to an external power source located outside the housing.

[0010] A pneumatic quick connector is provided on the pressure sealing flange, which can be connected to a pressure device located outside the housing.

[0011] The present invention also has the following technical features:

[0012] Specifically, the first inner wall and the second inner wall of the housing are respectively provided with mounting grooves. Metal clamping pieces for clamping glass slides are provided in the mounting grooves. The metal clamping pieces are connected to conductive posts that pass through the first inner wall and the second inner wall into the housing.

[0013] Furthermore, the loading pressure of the pressurized sealed combustion chamber is less than or equal to 0.6 MPa.

[0014] Furthermore, the housing is a transparent housing, and high-speed cameras for acquiring images of the single-particle ignition and combustion process are evenly distributed on the outer sides of the first and second inner sidewalls.

[0015] Furthermore, the conductive post and the metal clamping plate are made of copper or stainless steel, and the diameter of the conductive post is 0.5 to 2.0 mm, and the wall thickness of the metal clamping plate is 0.05 to 0.2 mm.

[0016] Furthermore, the heating wire is made of one of nickel-chromium alloy, iron-chromium-aluminum alloy, or nickel-manganese alloy, and the diameter of the heating wire is 0.05–0.2 mm.

[0017] Furthermore, the energetic materials include RDX, octogen, hexanitrohexaazaisowulzane, metastable intermolecular complexes, highly active metals, and highly active nonmetals.

[0018] Furthermore, the glass slide is made of quartz glass and has a thickness of 0.9–1.2 mm.

[0019] This invention also protects a method for igniting a single energetic material particle in a closed pressurized environment using a heating wire. The method is implemented using the aforementioned device for igniting a single energetic material particle in a closed pressurized environment using a heating wire, and includes the following steps:

[0020] Step 1: Place a single particle of energetic material on the heating wire of a glass slide, then place the glass slide into the housing, and seal the housing, the pressure sealing flange and the sealing flange to form a pressure-sealed combustion chamber;

[0021] Step 2: Connect the positive and negative terminals of the external power supply to the two conductive posts respectively, and set the output parameters of the external power supply; connect the pneumatic quick connector to the pressurization device;

[0022] Step 3: Inert gas is introduced into the pressurized closed combustion chamber through a pressurizing device to create high pressure in the pressurized closed combustion chamber; the external power supply is turned on to heat the heating wire to achieve ignition and combustion of the single particles of energetic material; during the combustion process of the single particles of energetic material, combustion images are captured by a high-speed camera.

[0023] Step 4: After the ignition and combustion test is completed, the pressurized and sealed combustion chamber is depressurized and the walls are cleaned.

[0024] Furthermore, the inert gas includes nitrogen, argon, and helium.

[0025] Compared with the prior art, the present invention has the following beneficial technical effects:

[0026] (1) The single-particle enclosed pressurized environment electric heating wire ignition device for energetic materials provided by the present invention has a simple structure. It uses an electric heating wire to heat and ignite the single particle of energetic material in a pressurized enclosed environment, which can effectively avoid the dissipation of radiation energy by the crystal structure during the radiation ignition process of laser or xenon lamp. It effectively solves the problems of pressurized environment sealing, external current introduction, electric heating wire power supply and glass slide fixation. While ensuring that the single particle of energetic material can be ignited, the overall reliability of the device operation is guaranteed.

[0027] (2) The method of the present invention can provide a high-temperature and high-pressure combustion environment for single particles of energetic materials more efficiently and simply. It can also more flexibly realize the observation of the ignition and combustion of single particles of energetic materials from a two-dimensional or three-dimensional perspective, effectively conduct non-interference testing of single particle micro-combustion under high-temperature and high-pressure environment, and better reveal its mechanism. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of the device of the present invention;

[0029] Figure 2 This is a partial structural schematic diagram of the present invention;

[0030] Figure 3 This is a schematic diagram of the heating and ignition assembly structure of the present invention;

[0031] Figure 4 This is an image of the combustion reaction of a single CL-20 particle in Example 2 of the present invention;

[0032] Figure label:

[0033] 1-Housing, 2-Pressure sealing flange, 3-Sealing flange, 4-Glass slide, 5-Heating wire, 6-Conductive column, 7-Pneumatic quick connector, 8-Metal clamping plate, 9-Observation window, 10-Fixing sleeve;

[0034] 11-First inner sidewall, 12-Second inner sidewall, 13-Mounting groove.

[0035] The technical solution of the present invention will be further described below with reference to the embodiments. Detailed Implementation

[0036] Following the above technical solutions, specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0037] As described in the background section, current ignition and combustion technologies based on laser ignition and planar flame burners have the following drawbacks: due to the energy dissipation of single-particle crystals of energetic materials by high-energy lasers or xenon lamps, it is difficult to ensure that the radiant energy is effectively conducted to the single particles of energetic materials and ignited; the planar flame furnace has high control requirements, and it is difficult to achieve a pressurized environment for highly discrete metal particles in the dynamic carry-over flow.

[0038] To overcome the shortcomings of the prior art described in the background section, this invention provides a closed-loop pressurized environment ignition device and method for single energetic material particles using an electric heating wire. By creating a pressurized environment within a sealed housing, energy transfer is achieved using an electric heating wire based on Joule's law, fundamentally improving the observation effect of ignition and combustion of single energetic material particles. The advantages of using electric heating wire ignition are: high ignition heating temperature (up to 1500℃), high reliability of heat transfer to the energetic material particles, and the ability to acquire ignition reaction images using a high-speed camera, thus enabling observation and recording of the ignition reaction process of single energetic material particles from a two-dimensional planar perspective or a three-dimensional perspective. Compared to existing devices and methods using laser ignition and planar flame burners for single-particle ignition, this invention effectively avoids the dissipation of radiation energy by the crystal, and the crystal particle size is not affected by the size of the focused spot or airflow. Furthermore, it has advantages such as simple device structure and convenient operation.

[0039] This invention proposes a technical solution for igniting single particles in a pressurized environment using a contact heating wire, changing the heat transfer method to heat conduction.

[0040] In summary, applying heating wire ignition to single particles of energetic materials effectively avoids the energy dissipation caused by the crystal structure during radiation ignition processes such as laser or xenon lamp ignition. It effectively solves problems related to pressurized environment sealing, external current introduction, heating wire power supply, and glass slide fixation, ensuring both the ability to ignite single particles of energetic materials and the overall reliability of the device.

[0041] It should be emphasized that, unless otherwise specified, all components used in this invention are commercially available.

[0042] Example 1

[0043] Following the above technical solutions, such as Figures 1 to 3 As shown in the figure, this embodiment discloses a closed pressurized environment electric heating wire ignition device for a single energetic material particle, including a shell 1 with open front and rear ends, a pressurized sealing flange 2 that can be detachably and sealingly connected to the front end of the shell 1, and a sealing flange 3 that can be detachably and sealingly connected to the rear end of the shell 1. The shell 1, the pressurized sealing flange 2, and the sealing flange 3 are sealed together to form a pressurized closed combustion chamber. A heating and ignition assembly is provided in the pressurized closed combustion chamber. The heating and ignition assembly is used to heat and ignite the single energetic material particle to be ignited in the pressurized closed combustion chamber.

[0044] The heating and ignition assembly includes a glass slide 4. The glass slide 4 has a fixing groove on each of its two opposite side walls for fixing the heating wire 5. The heating wire 5 can be connected to two conductive posts 6 that extend into the pressurized and sealed combustion chamber through the two side walls. The two conductive posts 6 are detachably connected to the positive and negative poles of an external power supply located outside the housing 1. The heating wire 5 can be heated to a higher temperature by electric heating.

[0045] A pneumatic quick connector 7 is provided on the pressure sealing flange 2, which can be connected to a pressure device located outside the housing 1.

[0046] In this embodiment, an air inlet and an air outlet are provided on the pressure sealing flange 2. Pneumatic quick connectors 7 are provided on both the air inlet and the air outlet. Each pneumatic quick connector 7 is connected to a PU tube, and each PU tube is equipped with a valve. When it is necessary to pressurize the pressure-sealed combustion chamber, the valve on the PU tube connected to the air inlet is opened and the valve on the PU tube connected to the air outlet is closed. When it is necessary to depressurize the pressure-sealed combustion chamber, the valve on the PU tube connected to the air inlet is closed and the valve on the PU tube connected to the air outlet is opened.

[0047] As a preferred embodiment, the first inner wall 11 and the second inner wall 12 of the housing 1 are respectively provided with mounting grooves 13. The mounting grooves 13 are provided with metal clamping pieces 8 for clamping glass slides 4. The metal clamping pieces 8 are fixedly connected to the conductive posts 6 that extend into the pressurized and sealed combustion chamber.

[0048] In this embodiment, the inner contour of the mounting groove 13 matches the outer contour of the metal clamping piece 8, and the mounting groove 13 can fit tightly with the metal clamping piece 8 to clamp the metal clamping piece 8 and restrict its movement. The inner contour of the metal clamping piece 8 matches the outer contour of the end of the glass slide 4 to clamp the glass slide 4 and restrict its movement.

[0049] As a preferred embodiment, the loading pressure of the pressurized closed combustion chamber is less than or equal to 0.6 MPa. The loading pressure is set to create a pressurized environment in the closed combustion chamber, while taking into account the tensile strength limit of the transparent shell 1, so as to ensure the safety of experimental instruments and operators.

[0050] As a preferred embodiment, the housing 1 is a transparent housing. In this embodiment, the housing 1 is made of plexiglass. High-speed cameras for image acquisition of the single-particle ignition and combustion process are evenly distributed on the outer sides of the first inner sidewall 11 and the second inner sidewall 12. The high-speed cameras can acquire images through the plexiglass.

[0051] As a preferred embodiment, the conductive post 6 and the metal clamping piece 8 are made of copper or stainless steel, and the diameter of the conductive post 6 is 0.5 to 2.0 mm, and the wall thickness of the metal clamping piece 8 is 0.05 to 0.2 mm. A fixing sleeve is also fitted on the outside of the conductive post 6 outside the housing 1. The fixing sleeve is used to seal the through holes opened on the first inner sidewall 11 and the second inner sidewall 12 for the conductive post 6 to pass through.

[0052] As a preferred embodiment, the heating wire 5 is made of one of nickel-chromium alloy, iron-chromium-aluminum alloy or nickel-manganese alloy, and the diameter of the heating wire 5 is 0.05-0.2 mm.

[0053] As a preferred embodiment, the energetic material includes RDX, octogen, hexanitrohexaazaisowulzane, metastable intermolecular complexes, highly active metals, and highly active nonmetals.

[0054] As a preferred embodiment, the glass slide 4 is made of quartz glass and has a thickness of 0.9 to 1.2 mm.

[0055] In use, the device of this invention is as follows: A heating wire is mounted on a glass slide 4, then a single energetic material particle is placed on the heating wire 5 of the glass slide 4. The glass slide 4 is then clipped into a metal clamping piece 8, which is then clipped into a mounting groove 13 for fixation. The pressure sealing flange 2 and the sealing flange 3 are then fastened to the housing 1 using bolts. After the housing 1, pressure sealing flange 2, and sealing flange 3 are sealed together, a pressure-sealed combustion chamber is formed. The positive and negative terminals of an external power supply are connected to two conductive posts 6, and the output parameters of the external power supply are set. A pneumatic quick connector 7 is connected to a pressurizing device, which pressurizes the pressure-sealed combustion chamber by filling it with inert gas, creating high pressure within the chamber. The external power supply is then turned on to heat the heating wire 5, thus igniting and burning the single energetic material particle.

[0056] Example 2

[0057] This embodiment discloses a method for igniting a single energetic material particle under closed pressurized environment with an electric heating wire. This method is implemented using the energetic material single-particle closed pressurized environment with an electric heating wire ignition device provided in Embodiment 1, and includes the following steps:

[0058] Step 1: Place a single particle of energetic material CL-20 on the heating wire of a glass slide, then place the glass slide into the housing, seal the housing, the pressure sealing flange and the sealing flange to form a pressure-sealed combustion chamber;

[0059] Step 2: Connect the positive and negative terminals of the external power supply to the two conductive posts respectively, and set the output parameters of the external power supply; connect the pneumatic quick connector to the pressurization device;

[0060] Step 3: Nitrogen gas is introduced into the pressurized closed combustion chamber through the pressurization device to create high pressure in the pressurized closed combustion chamber; the external power supply is turned on to heat the heating wire, and the CL-20 single particle undergoes an ignition reaction in the high-temperature heating environment. During the combustion process of the energetic material single particle, combustion images are collected through the observation window using a high-speed camera.

[0061] Step 4: After the ignition and combustion test is completed, the pressurized and sealed combustion chamber is depressurized and cooled.

[0062] Figure 4 The image obtained shows the ignition and combustion process of a single CL-20 particle. It can be seen from the image that the single CL-20 particle undergoes a crystal phase transition, releases flue gas, undergoes a violent reaction and extinguishes itself in a short period of time. Among them, the CL-20 single particle retains a lot of carbon skeleton structure after combustion reaction under normal pressure, while the CL-20 single particle basically completes combustion reaction under 0.2 MPa pressure.

[0063] This embodiment illustrates that the method provided by the present invention can effectively acquire combustion images of the combustion process of single particles of energetic materials, so as to further analyze the combustion of single particles of energetic materials.

[0064] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0065] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0066] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A method of igniting an energetic material single particle in a closed pressurized environment by an electrically heated wire, characterized in that, The method is realized by means of an electric heating wire ignition device in a single particle closed pressurized environment of energetic material, the device comprises a shell (1) with open front and rear ends, further comprises a pressurized sealing flange (2) capable of detachable sealing connection with the front end of the shell (1), and a sealing flange (3) capable of detachable sealing connection with the rear end of the shell (1), the shell (1), the pressurized sealing flange (2) and the sealing flange (3) are sealingly connected to form a pressurized closed combustion chamber, a heating ignition assembly is arranged in the pressurized closed combustion chamber; The heating ignition assembly comprises a glass slide (4), the opposite two side walls of the glass slide (4) are provided with fixing grooves for fixing electric heating wires (5), the electric heating wires (5) are connected with conductive columns (6) extending into the pressurized closed combustion chamber, the conductive columns (6) are detachably connected with an external power source arranged outside the shell (1); The pressurized sealing flange (2) is provided with a pneumatic quick connector (7), the pneumatic quick connector (7) is capable of connecting a pressurizing device arranged outside the shell (1); The gas pressure in the pressurized closed combustion chamber is less than or equal to 0.6 MPa; The method comprises the following steps: Step 1, place the single particle of energetic material on the glass slide and close to the electric heating wire, then put the glass slide into the shell, sealingly connect the shell, the pressurized sealing flange and the sealing flange to form a pressurized closed combustion chamber; Step 2, connect the positive and negative poles of the external power source to the two conductive columns respectively, set the output parameters of the external power source, and connect the pneumatic quick connector to the pressurizing device; Step 3, fill the inert gas into the pressurized closed combustion chamber through the pressurizing device to form high pressure in the pressurized closed combustion chamber, turn on the external power source to heat the electric heating wire, realize the ignition and combustion of the single particle of energetic material, and collect the combustion image by means of a high-speed camera during the combustion process of the single particle of energetic material; Step 4, after the ignition and combustion test is completed, perform the pressure relief treatment and wall cleaning of the pressurized closed combustion chamber; The inert gas comprises nitrogen, argon and helium; The first inner side wall (11) and the second inner side wall (12) of the shell (1) are provided with mounting grooves (13), the mounting grooves (13) are provided with metal clamping pieces (8) for clamping the glass slide (4), and the metal clamping pieces (8) are fixedly connected with the conductive columns (6) extending into the pressurized closed combustion chamber; The shell (1) is a transparent shell, the first inner side wall (11) and the second inner side wall (12) are provided with high-speed cameras for collecting the image of the single particle ignition and combustion process; The energetic material comprises black powder, octogen, hexanitrohexaazaisowurtzitane, metastable intermolecular complexes, high-activity metals and high-activity nonmetals.

2. The energetic material single grain pressurized environment hot-wire ignition method of claim 1, wherein, The material of the conductive column (6) and the metal clamping piece (8) is copper or stainless steel, the diameter of the conductive column (6) is 0.5-2.0 mm, the wall thickness of the metal clamping piece (8) is 0.05-0.2 mm, and the rear end of the conductive column (6) is further provided with a fixed clamping sleeve (10).

3. The energetic material single particle pressurized environment hot wire ignition method of claim 1, wherein, The material of the electric heating wire (5) is one of nickel-chromium alloy, iron-chromium-aluminum alloy or nickel-manganese alloy, and the diameter of the electric heating wire (5) is 0.05-0.2mm.

4. The energetic material single grain pressurized environment hot-wire ignition method of claim 1, wherein, The material of the glass slide (4) is quartz glass, and the thickness of the glass slide (4) is 0.9-1.2mm.

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