Dust cloud minimum ignition energy testing device and testing method

Abstract

The invention discloses a dust cloud minimum ignition energy testing device and method, in the testing device, a transparent testing bin is arranged in a heat insulation box body and used for ignition testing, and a gas supply unit, a temperature control unit, a powder supply unit and an ignition unit are arranged to achieve automatic control of testing conditions and ignition operation. Meanwhile, the flame detection unit is arranged to automatically monitor the ignition condition, the self-cleaning unit can automatically clean the transparent test bin before each ignition test, the control unit is used for automatic control, the ignition test of the dust cloud and the automatic monitoring of the ignition condition can be repeatedly carried out, and the test efficiency is improved. And full-automatic testing of the minimum ignition energy of the dust cloud is realized.

Description

Technical Field

[0001] This application relates to the field of explosion-proof safety technologies, and particularly to a device and method for testing the minimum ignition energy of a dust cloud. Background Art

[0002] The minimum ignition energy of a dust cloud is a fundamental parameter for dust electrostatic evaluation and prevention, as well as for evaluating the ignition probability of friction and impact. It is also involved in the possibility grading and risk assessment of dust explosion evaluation, and is a key parameter for dust explosion risk assessment. Among the testing equipment for the minimum ignition energy of a dust cloud in various domestic and foreign scientific research institutions, the vast majority use a 1.2L Hartmann tube minimum ignition energy device. Currently, these testing equipment only conduct tests for one case of room temperature / air atmosphere, and all are manual operations. Multiple ignition tests and data recording and analysis are required to obtain the minimum ignition energy, resulting in low testing efficiency. Moreover, repeated operations are also prone to errors in test results. Summary of the Invention

[0003] The purpose of this application is to overcome the deficiencies of low efficiency and large errors caused by manual testing and recording of the minimum ignition energy in the prior art, and to provide a device and method for testing the minimum ignition energy of a dust cloud that can achieve automatic testing of the minimum ignition energy of a dust cloud.

[0004] The technical solution of this application provides a device for testing the minimum ignition energy of a dust cloud, including

[0005] An adiabatic box body, in which a transparent test chamber is arranged;

[0006] A gas supply unit for supplying gas to the transparent test chamber to make the test gas environment in the transparent test chamber reach the required state;

[0007] A temperature control unit arranged in the adiabatic box body for regulating the temperature in the adiabatic box body to reach the test temperature environment;

[0008] A powder supply unit arranged in the adiabatic box body for storing powder and providing powder to the transparent test chamber to form a dust cloud in the transparent test chamber;

[0009] An ignition unit arranged in the transparent test chamber for adjusting the ignition energy to conduct an ignition test on the dust cloud in the transparent test chamber;

[0010] A flame detection unit arranged on the transparent test chamber for monitoring whether the dust cloud is ignited and the flame temperature;

[0011] A self-cleaning unit arranged on the transparent test chamber for self-cleaning the transparent test chamber before each ignition test;

[0012] A control unit, which is communicatively connected to the transparent test chamber, the gas supply unit, the temperature control unit, the powder supply unit, the ignition unit, the flame detection unit and the self-cleaning unit, is configured to control the gas supply unit, the temperature control unit, the powder supply unit, the ignition unit, the flame detection unit and the self-cleaning unit to perform ignition tests on the dust cloud multiple times to determine the minimum ignition energy of the dust.

[0013] Further, the gas supply unit includes a gas storage tank, an oxygen gas source, an inert gas source, an oxygen regulating valve, an inert gas regulating valve, an intake valve, a gas supply valve, a pressure detection component and an oxygen concentration detection component;

[0014] The gas storage tank is arranged in the adiabatic box body. The oxygen gas source is connected to the first end of the intake valve through the oxygen regulating valve. The inert gas source is connected to the first end of the intake valve through the inert gas regulating valve. The second end of the intake valve is connected to the gas storage tank. The gas storage tank is also connected to the transparent test chamber through the gas supply valve;

[0015] The pressure detection component is used to detect the pressure of the gas storage tank, and the oxygen concentration detection component is used to detect the oxygen concentration in the transparent test chamber;

[0016] The oxygen regulating valve, the inert gas regulating valve, the intake valve, the gas supply valve, the pressure detection component and the oxygen concentration detection component are all communicatively connected to the control unit.

[0017] Further, the temperature control unit includes a heating element, a circulation fan, a gas preheating coil, an air temperature detection component, a material temperature detection component and a test temperature detection component;

[0018] The heating element and the circulation fan are installed in the adiabatic box body. The gas preheating coil is wound around the heating element, and both ends of the gas preheating coil are respectively connected to the intake valve and the gas storage tank;

[0019] The air temperature detection component is used to detect the temperature in the gas storage tank, the material temperature detection component is used to detect the temperature of the powder supply unit, and the test temperature detection component is used to detect the temperature in the transparent test chamber;

[0020] The heating element, the circulation fan, the air temperature detection component, the material temperature detection component and the test temperature detection component are all communicatively connected to the control unit.

[0021] Further, the powder supply unit includes a powder storage bin, a weight detection component and a feeding component;

[0022] The powder storage bin is used to store powder materials. The weight detection component is installed on the powder storage bin and is used to detect the weights of the powder storage bin and the feeding component. The feeding end of the feeding component is connected to the powder storage bin, and the discharging end of the feeding component is connected to the pipeline between the air supply valve and the transparent test chamber.

[0023] Further, the transparent test chamber is connected with an air inlet pipe. One end of the air inlet pipe extends into the bottom of the transparent test chamber, and the other end is connected to the air supply valve.

[0024] A dust nozzle is provided at the end of the air inlet pipe extending into the transparent test chamber. A feeding part is provided on the air inlet pipe, and the discharging end of the feeding component is connected to the feeding part.

[0025] Further, the flame detection unit includes an incident lens, an exit lens, an atomic spectral light source, a spectroscope, and a spectral detector.

[0026] The incident lens and the exit lens are oppositely arranged on the side wall of the adiabatic box body, and the transparent test chamber is located between the incident lens and the exit lens.

[0027] The atomic spectral light source is installed on the incident lens, and its light-emitting end faces the incident lens. The spectroscope and the spectral detector are installed on one side of the exit lens. The spectroscope is used to receive the emitted light of the atomic spectral light source and perform spectral splitting, and the spectral detector is used to detect the split spectrum.

[0028] Both the atomic spectral light source and the spectral detector are communicatively connected to the control unit.

[0029] Further, the self-cleaning unit includes a blower, a dust collector, and a cleaning valve.

[0030] The air inlet end of the dust collector is connected to the transparent test chamber through the cleaning valve, and the air outlet end of the dust collector is connected to the air inlet end of the blower.

[0031] Both the blower, the dust collector, and the cleaning valve are communicatively connected to the control unit.

[0032] Further, a breathable film is provided on the inner wall of the transparent test chamber, and the self-cleaning unit further includes a backflush valve.

[0033] The transparent test chamber is provided with a backflush interface, and the backflush valve is connected to the backflush interface.

[0034] Further, a magnetic sealing cover and a switch electromagnetic component are installed on the transparent test chamber. The magnetic sealing cover is rotatably installed on the opening of the transparent test chamber. The switch electromagnetic component is communicatively connected to the control unit, and the magnetic sealing cover is adsorbed or opened by changing the current direction of the switch electromagnetic component.

[0035] The technical solution of the present application also provides a method for testing the minimum ignition energy of a dust cloud based on the aforementioned dust cloud minimum ignition energy testing device, including

[0036] Single ignition test step:

[0037] Control the temperature control unit to adjust the temperature in the adiabatic box to reach the test temperature environment;

[0038] Control the gas supply unit to prepare gas according to the test gas environment;

[0039] Control the self-cleaning unit to start and perform self-cleaning on the transparent test chamber;

[0040] Control the gas supply unit to supply gas to the transparent test chamber to make the transparent test chamber reach the test gas environment;

[0041] Control the powder supply unit to provide powder with a target test mass to the transparent test chamber and form a dust cloud;

[0042] After a target waiting period, control the ignition unit to ignite the dust cloud in the transparent test chamber with a target test energy. At the same time, control the flame detection unit to detect whether the dust cloud is ignited and the flame temperature and record the data;

[0043] According to the preset test process, adjust the target test mass, and / or the target waiting period, and / or the target test energy, and repeat the single ignition test step to determine the minimum ignition energy of the dust cloud.

[0044] Further, the step of adjusting the target test mass, and / or the target waiting period, and / or the target test energy according to the preset test process and repeating the single ignition test step to determine the minimum ignition energy of the dust cloud specifically includes:

[0045] Taking the preset maximum energy as the target test energy and the first waiting period as the target waiting period, sequentially change the target test mass according to the preset test mass gradient table and execute the single ignition test step. Select the test mass with the highest flame temperature and fix it as the target test mass. If the dust cloud is not ignited under all test masses in the preset test mass gradient table, then select the maximum test mass and fix it as the target test mass;

[0046] Maintain the target test quality, use the bisection method to sequentially change the target test energy, execute the single ignition test step with the first waiting duration as the target waiting duration, and determine the first lowest test energy at which the dust cloud ignites and the first highest test energy at which the dust cloud does not ignite;

[0047] Maintain the target test quality, use the first highest test energy as the target test energy, and execute the single ignition test step with the second waiting duration and the third waiting duration as the target waiting durations respectively. If the dust cloud does not ignite in both cases, determine the first lowest test energy as the minimum ignition energy of the dust cloud.

[0048] Furthermore, if, when maintaining the target test quality, using the first highest test energy as the target test energy and the second waiting duration as the target waiting duration to execute the single ignition test step, the dust cloud ignites, then

[0049] Maintain the target test quality, use the bisection method to sequentially change the target test energy, execute the single ignition test step with the second waiting duration as the target waiting duration, and determine the second lowest test energy at which the dust cloud ignites and the second highest test energy at which the dust cloud does not ignite;

[0050] Maintain the target test quality, use the second highest test energy as the target test energy, and execute the single ignition test step with the third waiting duration as the target waiting duration:

[0051] If the dust cloud does not ignite, determine the second lowest test energy as the minimum ignition energy of the dust cloud;

[0052] If the dust cloud ignites, maintain the target test quality, use the bisection method to sequentially change the target test energy, execute the single ignition test step with the third waiting duration as the target waiting duration, and determine the third lowest test energy at which the dust cloud ignites as the minimum ignition energy of the dust cloud.

[0053] Furthermore, if, when maintaining the target test quality, using the first highest test energy as the target test energy and the third waiting duration as the target waiting duration to execute the single ignition test step, the dust cloud ignites, then

[0054] Maintain the target test quality, use the bisection method to sequentially change the target test energy, execute the single ignition test step with the third waiting duration as the target waiting duration, and determine the third lowest test energy at which the dust cloud ignites as the minimum ignition energy of the dust cloud.

[0055] Further, when maintaining the target test quality, the target test energy is sequentially changed by the dichotomy method, and the first waiting duration is used as the target waiting duration to execute the single ignition test step. If the target test energy is reduced to be less than or equal to the preset minimum test energy and the dust cloud is not ignited, then

[0056] When maintaining the target test quality, the target test energy is sequentially changed from the preset maximum energy by the dichotomy method, and the second waiting duration is used as the target waiting duration to execute the single ignition test step. If the target test energy is reduced to be less than or equal to the preset minimum test energy and the dust cloud is not ignited, then

[0057] When maintaining the target test quality, the target test energy is sequentially changed from the preset maximum energy by the dichotomy method, and the third waiting duration is used as the target waiting duration to execute the single ignition test step. If the target test energy is reduced to be less than or equal to the preset minimum test energy and the dust cloud is not ignited, it is determined that the minimum ignition energy of the dust cloud is greater than the preset maximum energy.

[0058] After adopting the above technical solution, the following beneficial effects are obtained:

[0059] In the test device, a transparent test chamber is arranged in the adiabatic box for ignition tests, and a gas supply unit, a temperature control unit, a powder supply unit, and an ignition unit are set to realize the automatic control of test conditions and ignition operations. At the same time, a flame detection unit is set to automatically monitor the ignition situation, and the self-cleaning unit can perform self-cleaning of the transparent test chamber before each ignition test. The test device can repeatedly perform ignition tests on the dust cloud and automatically monitor the ignition situation, realizing the full-automatic test of the minimum ignition energy of the dust cloud. Description of the Drawings

[0060] Referring to the drawings, the disclosure of the present application will become easier to understand. It should be understood that these drawings are only for illustrative purposes and are not intended to limit the protection scope of the present application. In the figures:

[0061] Figure 1 is a schematic structural module diagram of a dust cloud minimum ignition energy test device in an embodiment of the present application;

[0062] Figure 2 is a dust cloud minimum ignition energy test device in an embodiment of the present application;

[0063] Figure 3 is a partially enlarged structural view of the powder supply unit in an embodiment of the present application;

[0064] Figure 4 is a first cross-sectional view of a dust nozzle in an embodiment of the present application;

[0065] Figure 5It is the second cross-sectional view of the dust nozzle in an embodiment of the present application;

[0066] Figure 6 It is the structural schematic diagram of the flame detection unit in an embodiment of the present application;

[0067] Figure 7 It is the structural schematic diagram of the transparent test chamber in an embodiment of the present application.

[0068] List of reference numerals:

[0069] Adiabatic box body 01;

[0070] Transparent test chamber 02: breathable film 21, backflush interface 22, magnetic seal cover 23, switch electromagnetic component 24;

[0071] Gas supply unit 03: gas storage tank 31, oxygen gas source 32, inert gas source 33, oxygen regulating valve 34, inert gas regulating valve 35, intake valve 36, gas supply valve 37, air pressure detection component 38, oxygen concentration detection component 39;

[0072] Temperature control unit 04: heating element 41, circulation fan 42, gas preheating coil 43, air temperature detection component 44, material temperature detection component 45, test temperature detection component 46;

[0073] Powder supply unit 05: powder storage bin 51, weight detection component 52, feeding component 53, intake pipe 54, feeding part 541, dust nozzle 55, spray hood 551, spray hole 552, base 553;

[0074] Ignition unit 06: high-voltage power supply 61, ignition electrode 62;

[0075] Flame detection unit 07: incident lens 71, exit lens 72, atomic spectral light source 73, spectroscope 74, spectral detector 75;

[0076] Self-cleaning unit 08: fan 81, dust collector 82, cleaning valve 83, backflush valve 84;

[0077] Control unit 09. Detailed implementation manners

[0078] The following further describes the detailed implementation manners of the present application with reference to the accompanying drawings.

[0079] It is easy to understand that according to the technical solution of the present application, under the condition of not changing the essential spirit of the present application, there are various structural manners and implementation manners that can be mutually replaced by those of ordinary skill in the art. Therefore, the following detailed implementation manners and the accompanying drawings are only exemplary descriptions of the technical solution of the present application, and should not be regarded as all of the present application or as a limitation or restriction on the technical solution of the application.

[0080] In this specification, the orientation terms such as up, down, left, right, front, back, front side, back side, top, bottom, etc., which are mentioned or may be mentioned, are defined relative to the structures shown in the respective drawings. They are relative concepts and may therefore change accordingly depending on their different positions and usage states. Therefore, these or other orientation terms should not be construed as restrictive terms. In addition, the terms "first", "second", "third" are used only for descriptive purposes and should not be construed as indicating or implying relative importance.

[0081] In the description of this application, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "linked" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0082] Dust cloud minimum ignition energy test device:

[0083] The dust cloud minimum ignition energy test device in the embodiment of this application, as Figure 1 , 2 shown, includes

[0084] An adiabatic box body 01, and a transparent test chamber 02 is arranged inside the adiabatic box body 01;

[0085] A gas supply unit 03, which is used to supply gas to the transparent test chamber 02 to make the test gas environment reach inside the transparent test chamber 02;

[0086] A temperature control unit 04, which is arranged inside the adiabatic box body 01 and is used to adjust the temperature inside the adiabatic box body 01 to reach the test temperature environment;

[0087] A powder supply unit 05, which is arranged inside the adiabatic box body 01 and is used to store powder and provide powder to the transparent test chamber 02 to form a dust cloud inside the transparent test chamber 02;

[0088] An ignition unit 06, which is arranged in the transparent test chamber 02 and is used to adjust the ignition energy to conduct an ignition test on the dust cloud in the transparent test chamber 02;

[0089] A flame detection unit 07, which is arranged on the transparent test chamber 02 and is used to monitor whether the dust cloud is ignited and the flame temperature;

[0090] A self-cleaning unit 08, which is arranged on the transparent test chamber 02 and is used to self-clean the transparent test chamber 02 before each ignition test;

[0091] The control unit 09 is communicatively connected to the transparent test chamber 02, the gas supply unit 03, the temperature control unit 04, the powder supply unit 05, the ignition unit 06, the flame detection unit 07, and the self-cleaning unit 08, and is configured to control the gas supply unit 03, the temperature control unit 04, the powder supply unit 05, the ignition unit 06, the flame detection unit 07, and the self-cleaning unit 08 to perform multiple ignition tests on the dust cloud to determine the minimum ignition energy of the dust.

[0092] Specifically, the transparent test chamber 02 can adopt a Hartmann tube. Multiple ignition tests are carried out by creating a dust cloud in the transparent test chamber 02 to determine the minimum ignition energy. The transparent test chamber 02 is arranged in the adiabatic box body 01 to prevent the energy flow between the inside and the outside environment of the transparent test chamber 02, so that the ignition test can be maintained in the set test temperature environment.

[0093] In the dust cloud minimum ignition energy test device in the embodiment of the present application, during the test, the control unit 09 controls the other units. The temperature control unit 04 heats the adiabatic box body 01 to make the inside of the adiabatic box body 01 reach the set test temperature environment. The gas supply unit 03 is used to supply gas to the transparent test chamber 02 to make the inside of the transparent test chamber 02 reach the test gas environment, so as to accurately control the temperature and gas conditions of the dust cloud ignition test; then the powder supply unit 05 supplies powder to the transparent test chamber to form a dust cloud in the transparent test chamber 02. The ignition unit 06 outputs ignition energy to the transparent test chamber 02 for ignition test. At the same time, the flame detection unit 07 monitors whether the dust cloud is ignited and the flame temperature; the self-cleaning unit 08 performs self-cleaning of the transparent test chamber 02 before each ignition test, enabling the test device to automatically repeat the ignition test of the dust cloud and automatically record the ignition situation, realizing the full-automatic test of the minimum ignition energy of the dust cloud.

[0094] In one embodiment, as Figure 2 shown, the gas supply unit 03 includes a gas storage tank 31, an oxygen gas source 32, an inert gas source 33, an oxygen regulating valve 34, an inert gas regulating valve 35, an intake valve 36, a gas supply valve 37, a pressure detection component 38, and an oxygen concentration detection component 39;

[0095] The gas storage tank 31 is arranged in the adiabatic box body 01. The oxygen gas source 32 is connected to the first end of the intake valve 36 through the oxygen regulating valve 34. The inert gas source 33 is connected to the first end of the intake valve 36 through the inert gas regulating valve 35. The second end of the intake valve 36 is connected to the gas storage tank 31. The gas storage tank 31 is also connected to the transparent test chamber 02 through the gas supply valve 37;

[0096] The pressure detection component 38 is used to detect the pressure of the gas storage tank 31, and the oxygen concentration detection component 39 is used to detect the oxygen concentration in the transparent test chamber 02;

[0097] The oxygen regulating valve 34, the inert gas regulating valve 35, the intake valve 36, the gas supply valve 37, the air pressure detecting member 38, and the oxygen concentration detecting member 39 are all communicatively connected to the control unit 09.

[0098] Specifically, the oxygen gas source 32 and the inert gas source 33 are arranged outside the adiabatic box 01. During the test, the opening degrees of the oxygen regulating valve 34 and the inert gas regulating valve 35 are adjusted respectively according to the preset oxygen concentration in the test gas environment, and the intake valve 36 is opened to supply gas to the gas storage tank 31 until the air pressure detecting member 38 detects that the air pressure of the gas storage tank 31 reaches the preset range, then the intake valve 36 is closed. The gas storage tank 31 is used to store the gas for the ignition test, and is heated inside the adiabatic box 01, and the ignition test is carried out after the gas reaches the test temperature environment.

[0099] After the gas is heated to the test temperature environment, the control gas supply valve 37 is opened to supply gas to the transparent test chamber 02 until the oxygen concentration detecting member 39 detects that the oxygen concentration in the transparent test chamber 02 reaches the preset oxygen concentration, and then the gas supply valve 37 is closed. At the same time, the intake valve 36 is continuously opened to supply gas to the gas storage tank 31 to keep the air pressure of the gas storage tank 31 within the preset range.

[0100] In one embodiment, as Figure 2 shown, the temperature control unit 04 includes a heating element 41, a circulation fan 42, a gas preheating coil 43, an air temperature detecting member 44, a material temperature detecting member 45, and a test temperature detecting member 46;

[0101] The heating element 41 and the circulation fan 42 are installed in the adiabatic box 01, the gas preheating coil 43 is wound around the heating element 41, and both ends of the gas preheating coil 43 are respectively connected to the intake valve 36 and the gas storage tank 31;

[0102] The air temperature detecting member 44 is used to detect the temperature inside the gas storage tank 31, the material temperature detecting member 45 is used to detect the temperature of the powder supply unit 05, and the test temperature detecting member 46 is used to detect the temperature inside the transparent test chamber 02;

[0103] The heating element 41, the circulation fan 42, the air temperature detecting member 44, the material temperature detecting member 45, and the test temperature detecting member 46 are all communicatively connected to the control unit 09.

[0104] Specifically, the heating element 41 can be set as a heating resistance wire plate and arranged in the adiabatic box body 01. Multiple circulating fans 42 can be evenly arranged around the heating element 41 so that the gas flow rate passing through the heating element 41 is greater than or equal to 2 m / s to balance the temperature of each area in the adiabatic box body 01. The gas preheating coil 43 is wound around the heating element 41. After the oxygen and inert gas are mixed, they flow into the gas preheating coil 43 through the intake valve 36, and then flow into the gas storage tank 31 after being heated by the gas preheating coil 43, realizing rapid preheating of the gas to shorten the heating time of the gas in the gas storage tank 31 and improve the test efficiency. The gas preheating coil 43 can be filled with filamentous high thermal conductivity materials, such as silver wires, copper wires, porous graphene, etc., and the filling rate is 40%-80%.

[0105] The air temperature detection element 44, the material temperature detection element 45, and the test temperature detection element 46 respectively detect the temperature in the gas storage tank 31, the temperature of the stored powder in the powder supply unit 05, and the temperature in the transparent test chamber 02. At the start of the test, the heating element 41 and the circulating fan 42 are started according to the test temperature environment. After the monitored temperature of the air temperature detection element 44 reaches the temperature required by the test temperature environment, gas is supplied to the transparent test chamber 02. After the monitored temperatures of the test temperature monitoring element 46 and the material temperature detection element 45 also reach the temperature required by the test temperature environment, powder is supplied to the transparent test chamber 02 and an ignition test is carried out.

[0106] In one embodiment, as Figure 2 shown, the powder supply unit 05 includes a powder storage bin 51, a weight detection element 52, and a feeding element 53;

[0107] The powder storage bin 51 is used to store powder. The weight detection element 52 is installed on the powder storage bin 51 to detect the mass of the powder storage bin 51 and the feeding element 53. The feeding end of the feeding element 53 is connected to the powder storage bin 51, and the discharging end of the feeding element 53 is connected to the pipeline between the gas supply valve 37 and the transparent test chamber 02.

[0108] Specifically, the feeding element 53 can adopt a precision screw feeder to feed slowly at a slower rate, which can accurately control the feeding amount. The weight detection element 52 detects the total weight of the powder storage bin 51 and the powder therein and the feeding element 53 during feeding, and judges the feeding weight through the change of the total weight.

[0109] The discharging end of the feeding element 53 is connected to the pipeline between the gas supply valve 37 and the transparent test chamber 02, and the powder is added to the pipeline between the gas supply valve 37 and the transparent test chamber 02. During the ignition test, the gas supply valve 37 is opened to supply gas to the transparent test chamber 02, and under the action of the air pressure in the gas storage tank 31, the gas blows the powder on the pipeline into the transparent test chamber 02 to form a dust cloud.

[0110] In one embodiment, as Figure 3As shown, the transparent test chamber 02 is connected to an intake pipe 54. One end of the intake pipe 54 extends into the bottom of the transparent test chamber 02, and the other end is connected to a gas supply valve 37.

[0111] At one end of the intake pipe 54 extending into the transparent test chamber 02, there is a dust nozzle 55. The intake pipe 54 is provided with a feeding part 541, and the discharging end of the feeding member 53 is connected to the feeding part 541.

[0112] Specifically, the diameter of the feeding part 541 is smaller than the diameter of the gas area of the intake pipe 54. The Venturi principle is used to generate negative pressure in the feeding part 541, so that the powder quickly mixes with the gas under the action of gravity and negative pressure and flows into the transparent test chamber 02.

[0113] The dust nozzle 55 is as Figure 4 、 5 shown. The dust nozzle 55 includes a base 553 and a spray hood 551. The spray hood 551 is rotatably mounted on the base 553. A cavity is formed inside the spray hood 551. The spray hood 551 is provided with spray holes 552 distributed spirally upward. After the powder is mixed in the gas and first enters the cavity, it is sprayed into the transparent test chamber 02 from the spray holes 552, thereby forming a dust cloud in the transparent test chamber 02. When the powder mixed gas is ejected from the spray holes 552, under the action of the centrifugal force of the air flow, the spray hood 551 rotates relative to the base 553, making the ejected dust more uniform. Preferably, the opening ratio of the spray holes 552 on the spray hood 551 is 60%-90%, the aperture of the spray holes 552 is 500μm to 1mm, and the angle between the axis of the spray holes 552 and the horizontal plane is 30°-60°.

[0114] In one embodiment, as Figure 6 shown, the flame detection unit 07 includes an incident lens 71, an exit lens 72, an atomic spectral light source 73, a spectroscope 74, and a spectral detector 75;

[0115] The incident lens 71 and the exit lens 72 are oppositely arranged on the side wall of the adiabatic box 01, and the transparent test chamber 02 is located between the incident lens 71 and the exit lens 72;

[0116] The atomic spectral light source 73 is installed on the incident lens 71, and its light-emitting end is arranged facing the incident lens 71. The spectroscope 74 and the spectral detector 75 are installed on one side of the exit lens 72. The spectroscope 74 is used to receive the emitted light of the atomic spectral light source 73 and perform spectroscopy, and the spectral detector 75 is used to detect the spectrum after spectroscopy;

[0117] Both the atomic spectral light source 73 and the spectral detector 75 are communicatively connected to the control unit 09.

[0118] Specifically, the incident lens 71 and the exit lens 72 are made of high-temperature-resistant and high-transmittance optical lenses. The atomic spectral light source 73 is used to emit resonance radiation for detecting one or more of the gases such as water molecules, carbon monoxide, carbon dioxide, and methane, and emits it towards the transparent test chamber 02 through the incident lens 71. The spectroscope 74 receives the resonance radiation light passing through the flame and performs spectroscopy to separate the resonance absorption lines from other spectral lines. The spectral detector 75 analyzes and determines the combustion condition and the flame temperature by comparing the resonance absorption lines with the pre-stored resonance absorption spectra at different temperatures, and sends the results to the control unit 09, where the combustion condition is determined by comparing the temperature difference between the highest temperature and the preset test temperature.

[0119] In one embodiment, the self-cleaning unit 08 includes a blower 81, a dust collector 82, and a cleaning valve 83;

[0120] The air inlet end of the dust collector 82 is connected to the transparent test chamber 02 through the cleaning valve 83, and the air outlet end of the dust collector 82 is connected to the air inlet end of the blower 81;

[0121] The blower 81, the dust collector 82, and the cleaning valve 83 are all communicatively connected to the control unit 09.

[0122] Specifically, the blower 81 and the dust collector 82 are arranged outside the adiabatic box 01. When self-cleaning the transparent test chamber 02, the blower 81 is started to extract the gas in the transparent test chamber 02 outwards. After the gas and dust in the transparent test chamber 02 pass through the dust collector 82 to remove the dust, the clean gas is discharged into the atmosphere, thereby realizing the self-cleaning of the transparent test chamber 02 and enabling the test device to automatically perform multiple ignition tests.

[0123] In one embodiment, as Figure 7 shown, the inner wall of the transparent test chamber 02 is provided with a breathable membrane 21, and the self-cleaning unit 08 further includes a backflush valve 84;

[0124] The transparent test chamber 02 is provided with a backflush interface 22, and a backflush valve 84 is connected to the backflush interface 22.

[0125] Specifically, the breathable membrane 21 can be made of a fire-resistant, high-toughness, and high-transmittance microporous breathable membrane. The breathable membrane 21 is arranged close to the inner wall of the transparent test chamber 02 but does not completely fit the inner wall of the transparent test chamber 02. When the transparent test chamber 02 is self-cleaning, the control unit 09 controls the backflush valve 84 to open and close periodically, thereby forming a pulsed air flow in the transparent test chamber 02. The pulsed air flow causes the breathable membrane 21 to vibrate, making the dust adhering to the breathable membrane 21 rise, enter the transparent test chamber 02 through the micropores on the breathable membrane 21, and enter the dust collector 82 along with the dust removal air flow.

[0126] In the embodiments of the present application, an air-permeable membrane 21, a backflush interface 22, and a backflush valve 84 are provided in the transparent test chamber 02, and the self-cleaning effect of the transparent test chamber 02 is further improved through the oscillation of the air-permeable membrane 21.

[0127] In one embodiment, as Figure 7 shown, a magnetic seal cover 23 and a switch electromagnetic component 24 are installed on the transparent test chamber 02. The magnetic seal cover 23 is rotatably installed on the opening of the transparent test chamber 02, and the switch electromagnetic component 24 is communicatively connected to the control unit 09. By changing the current direction of the switch electromagnetic component 24, the switch electromagnetic component 24 is controlled to adsorb or open the magnetic seal cover 23.

[0128] Specifically, the magnetic seal cover 23 is flipably installed on the opening of the transparent test chamber 02. The switch electromagnetic component 24 is an electromagnet, which is arranged on the opening of the transparent test chamber 02. The control unit 09 changes the current direction of the switch electromagnetic component 24 to make the switch electromagnetic component 24 adsorb or open the magnetic seal cover 23, realizing the automatic opening and closing of the transparent test chamber 02. When the transparent test chamber 02 is self-cleaning, the magnetic seal cover 23 is opened, and then gas is supplied to the transparent test chamber 02. When it is detected that the oxygen concentration in the transparent test chamber 02 reaches the preset oxygen concentration, the magnetic seal cover 23 is controlled to close until the ignition test ends, and then the magnetic seal cover 23 is opened again.

[0129] Furthermore, the ignition unit 06 includes a high-voltage power supply 61 and an ignition electrode 62 electrically connected to the high-voltage power supply 61. The high-voltage power supply 61 is arranged outside the adiabatic box 01 to ensure safety. The high-voltage power supply 61 leads out a positive wiring and a negative wiring as the ignition electrode 62 and inserts them into the transparent test chamber 02. Two opposite electrode sockets are provided on the side wall of the transparent test chamber 02. The two ignition electrodes 62 are respectively inserted into the transparent test chamber 02 from the electrode sockets. A gap is provided between the ends of the two ignition electrodes 62. During the ignition test, the control unit 09 controls the high-voltage power supply 61 to discharge, and a spark is generated between the two ignition electrodes 62 due to the high voltage, thereby igniting the dust cloud. By adjusting the discharge voltage of the high-voltage power supply 61, the ignition energy can be adjusted.

[0130] According to needs, the above technical solutions can be combined to achieve the best technical effect.

[0131] The minimum ignition energy test method for dust cloud in the embodiments of the present application is based on the minimum ignition energy test device for dust cloud in any of the foregoing embodiments, and includes

[0132] Single ignition test steps:

[0133] Control the temperature control unit to adjust the temperature in the adiabatic box to reach the test temperature environment;

[0134] Control the gas supply unit to prepare gas according to the test gas environment;

[0135] Control the self - cleaning unit to start and perform self - cleaning on the transparent test chamber;

[0136] Control the gas supply unit to supply gas to the transparent test chamber to make the transparent test chamber reach the test gas environment;

[0137] Control the powder supply unit to provide powder with a target test mass to the transparent test chamber and form a dust cloud;

[0138] After a target waiting duration, control the ignition unit to ignite the dust cloud in the transparent test chamber with a target test energy, and at the same time control the flame detection unit to detect whether the dust cloud is ignited and the flame temperature and record the data;

[0139] According to the preset test process, adjust the target test mass, and / or the target waiting duration, and / or the target test energy, and repeat the single - ignition test step to determine the minimum ignition energy of the dust cloud.

[0140] Specifically, before the test, receive the test temperature environment and test gas environment set by the user. The test temperature environment includes the test temperature, and the test gas environment includes the air pressure, oxygen concentration, etc. After the test environment is set, adjust at least one variable among the target test mass, target waiting duration, and target test energy according to the preset test process, and repeat the single - ignition test step to determine the minimum ignition energy of the dust cloud.

[0141] In the single - ignition step, first control the temperature control unit to adjust the temperature in the adiabatic box to reach the test temperature environment. Due to the time delay of temperature regulation, in order to save heating time, start the temperature control unit first, control the heating element 41 and the circulation fan 42 to start, and real - time monitor the test temperature data of the air temperature detection element 44, the material temperature detection element 45, and the test temperature detection element 46, and adjust the heating temperature of the heating element 41 according to the test temperature data.

[0142] After starting the temperature control unit, according to the test gas environment, control the oxygen regulating valve 34, the inert gas regulating valve 35, and the intake valve 36 of the gas supply unit 03 to open, supply gas to the gas storage tank 31, heat the gas in the gas storage tank 31 to the test temperature, and close the intake valve 36 to stop gas supply when the air pressure detection element 38 detects that the air pressure in the gas storage tank 31 reaches the preset air pressure range.

[0143] Then control the fan 81 and the cleaning valve 83 of the self - cleaning unit 08 to start, and the back - blowing valve 84 is periodically opened and closed, and the time interval between opening and closing is 1 - 3 s, and perform self - cleaning on the transparent test chamber 02, and the self - cleaning time is set to at least 2 min.

[0144] After the self - cleaning of the transparent test chamber 02 is completed, control the current of the control switch electromagnetic part 24 to open the magnetic sealing cover 23. At the same time, control the gas supply valve 37 to open. The gas storage tank 31 supplies gas to the transparent test chamber 02. At the same time, the oxygen concentration detection part 39 detects the oxygen concentration in the transparent test chamber 02. When the oxygen concentration reaches the set oxygen concentration, control the switch solenoid valve 24 to close the magnetic sealing cover 23 and close the gas supply valve 37 at the same time. After the gas storage tank 31 supplies gas and the air pressure detection part 38 detects a decrease in air pressure, the intake valve 37 is opened to continue supplying gas to the gas storage tank 31.

[0145] After that, obtain the detection data of the air temperature detection part 44, the material temperature detection part 45, the test temperature detection part 46 and the air pressure detection part 38. If they all reach the preset range, control the feeding part 53 of the feeding unit 05 to start, add the powder of the target test mass to the feeding part 541, and then open the gas supply valve 37 to make the powder in the feeding part 541 enter the transparent test chamber 02 under the action of air flow and form a dust cloud by spraying.

[0146] After the gas supply valve 37 is opened, delay the target waiting time to control the ignition unit 06 to ignite the dust cloud in the transparent test chamber 02 with the target test energy. At the same time, control the flame detection unit 07 to detect whether the dust cloud is ignited and the flame temperature and record the data.

[0147] In the dust cloud minimum ignition energy test method in the embodiment of the present application, based on the dust cloud minimum ignition energy test device, under the control of the control unit 09, multiple ignition tests can be automatically carried out to measure the minimum ignition energy of the dust.

[0148] In one of the embodiments, according to the preset test process, adjust the target test mass, and / or the target waiting time, and / or the target test energy to repeat the single - ignition test step to determine the minimum ignition energy of the dust cloud. Specifically, it includes:

[0149] Take the preset maximum energy as the target test energy, take the first waiting time as the target waiting time, and change the target test mass in turn according to the preset test mass gradient table to execute the single - ignition test step. Select the test mass with the highest flame temperature and fix it as the target test mass. If the dust cloud is not ignited under all test masses in the preset test mass gradient table, select the maximum test mass and fix it as the target test mass;

[0150] Maintain the target test mass, use the dichotomy method to change the target test energy in turn, take the first waiting time as the target waiting time to execute the single - ignition test step, and determine the first lowest test energy at which the dust cloud is ignited and the first highest test energy at which the dust cloud is not ignited;

[0151] Maintain the target test quality. Take the first highest test energy as the target test energy, and execute the single ignition test step with the second waiting duration and the third waiting duration as the target waiting durations respectively. If the dust cloud does not ignite in both cases, determine the first lowest test energy as the minimum ignition energy of the dust cloud.

[0152] Specifically, the preset test quality gradient table can be set according to the dust properties and test requirements, which includes multiple test qualities. The test qualities are executed in ascending order to perform the single ignition test step and collect the flame temperature. In each single ignition test, the target test energy is set to the preset maximum energy, such as 1000 mJ, and the target waiting duration is set to the first waiting duration, such as 120 ms. Then, select the test quality corresponding to the single ignition test step with the highest flame temperature and fix it as the target test quality. In subsequent single ignition tests, this test quality is used as the target test quality. If the dust cloud does not ignite under all test qualities in the preset test quality gradient table, select the maximum test quality and fix it as the target test quality.

[0153] After determining the target test quality through the above steps, use the bisection method to sequentially change the target test energy. For example, if the current target test energy is 1000 mJ, then sequentially use 500 mJ, 250 mJ, 175 mJ... as the target test energy, and execute the single ignition test step with the first waiting duration as the target waiting duration to determine the first lowest test energy at which the dust cloud ignites and the first highest test energy at which the dust cloud does not ignite.

[0154] After that, maintain the target test quality. Take the first highest test energy as the target test energy, and execute the single ignition test step with the second waiting duration and the third waiting duration as the target waiting durations respectively. If the dust cloud does not ignite in both cases, determine the first lowest test energy as the minimum ignition energy of the dust cloud. The second waiting duration can be set to 60 ms, and the third waiting duration can be set to 180 ms.

[0155] Preferably, to improve the accuracy of the single ignition step, if ignition does not occur, control the ignition unit to start for ignition again. In the single ignition step, the maximum number of starts of the ignition unit is 10 times. If ignition does not occur in all 10 times, it is determined that the dust does not ignite in this single ignition step.

[0156] After determining the target test quality in the embodiment of the present application, taking the first waiting duration as the target waiting duration, using the dichotomy method to sequentially reduce the target test energy to perform a single ignition step, after determining the first minimum test energy at which the dust cloud is ignited and the first maximum test energy at which the dust cloud is not ignited, continue to perform the single ignition step by fine-tuning the target waiting duration. If the dust cloud is not ignited after fine-tuning the target waiting duration, then judge the first minimum test energy as the minimum ignition energy of the dust cloud, improving the test accuracy of the minimum ignition energy.

[0157] In one of the embodiments, if the target test quality is maintained, taking the first maximum test energy as the target test energy and the second waiting duration as the target waiting duration to perform the single ignition test step, and if the dust cloud is ignited, then

[0158] Maintain the target test quality, use the dichotomy method to sequentially change the target test energy, take the second waiting duration as the target waiting duration to perform the single ignition test step, and determine the second minimum test energy at which the dust cloud is ignited and the second maximum test energy at which the dust cloud is not ignited;

[0159] Maintain the target test quality, take the second maximum test energy as the target test energy, and take the third waiting duration as the target waiting duration to perform the single ignition test step:

[0160] If the dust cloud is not ignited, then determine the second minimum test energy as the minimum ignition energy of the dust cloud;

[0161] If the dust cloud is ignited, then maintain the target test quality, use the dichotomy method to sequentially change the target test energy, take the third waiting duration as the target waiting duration to perform the single ignition test step, and determine the third minimum test energy at which the dust cloud is ignited as the minimum ignition energy of the dust cloud.

[0162] After the embodiment of the present application determines the first minimum test energy at which the dust cloud is ignited and the first maximum test energy at which the dust cloud is not ignited, continue to perform the single ignition step by fine-tuning the target waiting duration. If the dust cloud is ignited after the target waiting duration is adjusted to the second waiting duration, then maintain the target test quality and the target waiting duration, and continue to use the dichotomy method to reduce the target test energy to perform the single ignition step, and determine the second minimum test energy at which the dust cloud is ignited and the second maximum test energy at which the dust cloud is not ignited.

[0163] After that, continue to fine-tune the target waiting duration to the third waiting duration, maintain the target test quality, and perform a single ignition step with the second highest test energy as the target test energy. If ignition does not occur, use the second lowest test energy as the minimum ignition energy of the dust cloud. If ignition occurs, continue to use the dichotomy method to reduce the target test energy, and perform a single ignition step with the third waiting duration as the target waiting duration to determine the third lowest test energy at which the dust cloud ignites as the minimum ignition energy of the dust cloud. By adjusting the target waiting duration, the minimum ignition energy of the dust cloud is determined. According to the requirements of test accuracy, the target waiting duration can also be further fine-tuned to perform a single ignition step to determine a more accurate minimum ignition energy. Generally speaking, after the target waiting duration is fine-tuned twice, the determined minimum ignition energy can already meet the requirements.

[0164] In one embodiment, if during the single ignition test step with the first highest test energy as the target test energy and the third waiting duration as the target waiting duration while maintaining the target test quality, the dust cloud ignites, then

[0165] Maintain the target test quality, use the dichotomy method to sequentially change the target test energy, and perform a single ignition test step with the third waiting duration as the target waiting duration to determine the third lowest test energy at which the dust cloud ignites as the minimum ignition energy of the dust cloud.

[0166] In the embodiment of the present application, after determining the first lowest test energy at which the dust cloud ignites and the first highest test energy at which the dust cloud does not ignite, continue to perform a single ignition step by fine-tuning the target waiting duration. If the dust cloud does not ignite after the target waiting duration is adjusted to the second waiting duration, and the dust cloud ignites after the target waiting duration is adjusted to the third waiting duration, then continue to use the dichotomy method to reduce the target test energy, and perform a single ignition step with the third waiting duration as the target waiting duration to determine the third lowest test energy at which the dust cloud ignites as the minimum ignition energy of the dust cloud.

[0167] In one embodiment, while maintaining the target test quality, use the dichotomy method to sequentially change the target test energy. If during the single ignition test step with the first waiting duration as the target waiting duration, the dust cloud does not ignite even when the target test energy is reduced to less than or equal to the preset minimum test energy, then

[0168] Maintain the target test quality, use the dichotomy method to sequentially change the target test energy from the preset maximum energy, and perform a single ignition test step with the second waiting duration as the target waiting duration. If the dust cloud does not ignite even when the target test energy is reduced to less than or equal to the preset minimum test energy, then

[0169] Maintain the target test quality, and use the dichotomy method to sequentially change the target test energy from the preset maximum energy. Take the third waiting duration as the target waiting duration and execute a single ignition test step. If the target test energy decreases to be less than or equal to the preset minimum test energy and the dust cloud does not ignite, it is determined that the minimum ignition energy of the dust cloud is greater than the preset maximum energy.

[0170] In the embodiment of the present application, after determining the target test quality, if the dichotomy method is used to reduce the target test energy, and in the single ignition test step with the first waiting duration as the target waiting duration, when the target test energy decreases to be less than or equal to the preset minimum test energy and the dust cloud does not ignite; then fine-tune the target waiting duration to the second waiting duration, and again use the dichotomy method to sequentially decrease the target test energy from the preset maximum energy. If it still does not ignite; then fine-tune the target waiting duration to the third waiting duration, and again use the dichotomy method to sequentially decrease the target test energy from the preset maximum energy. If it still does not ignite, it is determined that the minimum ignition energy of the dust cloud is greater than the preset maximum energy, and the test process ends.

[0171] The above are only the principles and preferred embodiments of the present application. It should be noted that for those of ordinary skill in the art, the implementation manners obtained by appropriately combining the technical solutions separately disclosed in different embodiments are also included within the technical scope of the present invention. Based on the principle of the present application, several other variations can also be made, which should also be regarded as the protection scope of the present application.

Claims

1. A device for testing the minimum ignition energy of a dust cloud, characterized in that, including an adiabatic box body, in which a transparent test chamber is arranged; a gas supply unit for supplying gas to the transparent test chamber to make the inside of the transparent test chamber reach a test gas environment; a temperature control unit arranged in the adiabatic box body for regulating the temperature in the adiabatic box body to reach a test temperature environment; a powder supply unit arranged in the adiabatic box body for storing powder and supplying the powder to the transparent test chamber to form a dust cloud in the transparent test chamber; an ignition unit arranged in the transparent test chamber for adjusting the ignition energy to conduct an ignition test on the dust cloud in the transparent test chamber; a flame detection unit arranged on the transparent test chamber for monitoring whether the dust cloud is ignited and the flame temperature; a self-cleaning unit arranged on the transparent test chamber for self-cleaning the transparent test chamber before each ignition test; a control unit communicatively connected to the transparent test chamber, the gas supply unit, the temperature control unit, the powder supply unit, the ignition unit, the flame detection unit and the self-cleaning unit, for controlling the gas supply unit, the temperature control unit, the powder supply unit, the ignition unit, the flame detection unit and the self-cleaning unit to conduct multiple ignition tests on the dust cloud to determine the minimum ignition energy of the dust.

2. The device for testing the minimum ignition energy of a dust cloud according to claim 1, characterized in that, The gas supply unit includes a gas storage tank, an oxygen gas source, an inert gas source, an oxygen regulating valve, an inert gas regulating valve, an intake valve, a gas supply valve, a pressure detection component and an oxygen concentration detection component; The gas storage tank is arranged in the adiabatic box body. The oxygen gas source is connected to the first end of the intake valve through the oxygen regulating valve, the inert gas source is connected to the first end of the intake valve through the inert gas regulating valve, the second end of the intake valve is connected to the gas storage tank, and the gas storage tank is also connected to the transparent test chamber through the gas supply valve; The pressure detection component is used for detecting the pressure of the gas storage tank, and the oxygen concentration detection component is used for detecting the oxygen concentration in the transparent test chamber; The oxygen regulating valve, the inert gas regulating valve, the intake valve, the gas supply valve, the pressure detection component and the oxygen concentration detection component are all communicatively connected to the control unit.

3. The device for testing the minimum ignition energy of a dust cloud according to claim 2, characterized in that, The temperature control unit includes a heating element, a circulation fan, a gas preheating coil, an air temperature detection component, a material temperature detection component and a test temperature detection component; The heating element and the circulation fan are installed in the adiabatic box body. The gas preheating coil is wound around the heating element, and both ends of the gas preheating coil are respectively connected to the intake valve and the gas storage tank; The air temperature detection component is used for detecting the temperature in the gas storage tank, the material temperature detection component is used for detecting the temperature of the powder supply unit, and the test temperature detection component is used for detecting the temperature in the transparent test chamber; The heating element, the circulation fan, the air temperature detection component, the material temperature detection component and the test temperature detection component are all communicatively connected to the control unit.

4. The device for testing the minimum ignition energy of a dust cloud according to claim 2, characterized in that, The powder supply unit includes a powder storage bin, a weight detection component and a feeding component; The powder storage bin is used to store powder materials. The weight detection component is installed on the powder storage bin and is used to detect the weights of the powder storage bin and the feeding component. The feeding end of the feeding component is connected to the powder storage bin, and the discharging end of the feeding component is connected to the pipeline between the air supply valve and the transparent test chamber.

5. The device for testing the minimum ignition energy of a dust cloud according to claim 4, characterized in that, The transparent test chamber is connected with an air inlet pipe. One end of the air inlet pipe extends into the bottom of the transparent test chamber, and the other end is connected to the air supply valve. A dust nozzle is arranged at one end of the air inlet pipe extending into the transparent test chamber. A feeding part is arranged on the air inlet pipe, and the discharging end of the feeding component is connected to the feeding part.

6. The device for testing the minimum ignition energy of a dust cloud according to claim 1, characterized in that, The flame detection unit includes an incident lens, an exit lens, an atomic spectral light source, a spectroscope and a spectral detector. The incident lens and the exit lens are oppositely arranged on the side wall of the adiabatic box body. The transparent test chamber is located between the incident lens and the exit lens. The atomic spectral light source is installed on the incident lens, and its light emitting end is arranged towards the incident lens. The spectroscope and the spectral detector are installed on one side of the exit lens. The spectroscope is used to receive the emitted light of the atomic spectral light source and perform spectral splitting, and the spectral detector is used to detect the spectrum after spectral splitting. Both the atomic spectral light source and the spectral detector are communicatively connected to the control unit.

7. The device for testing the minimum ignition energy of a dust cloud according to claim 1, characterized in that, The self-cleaning unit includes a blower, a dust collector and a cleaning valve. The air inlet end of the dust collector is connected to the transparent test chamber through the cleaning valve, and the air outlet end of the dust collector is connected to the air inlet end of the blower. The blower, the dust collector and the cleaning valve are all communicatively connected to the control unit.

8. The device for testing the minimum ignition energy of a dust cloud according to claim 7, characterized in that, A breathable film is arranged on the inner wall of the transparent test chamber. The self-cleaning unit further includes a backflush valve. The transparent test chamber is provided with a backflush interface, and the backflush valve is connected to the backflush interface.

9. The minimum ignition energy test device for dust cloud according to claim 1, characterized in that, A magnetic sealing cover and a switch electromagnetic component are installed on the transparent test chamber. The magnetic sealing cover is rotatably installed on the opening of the transparent test chamber. The switch electromagnetic component is communicatively connected to the control unit, and the magnetic sealing cover is adsorbed or opened by changing the current direction of the switch electromagnetic component.

10. A method for testing the minimum ignition energy of a dust cloud based on the minimum ignition energy test device for a dust cloud according to any one of claims 1-9, characterized in that, Including Single ignition test steps: Control the temperature control unit to adjust the temperature in the adiabatic box body to reach the test temperature environment. Control the air supply unit to prepare gas according to the test gas environment. Control the self-cleaning unit to start and perform self-cleaning on the transparent test chamber. Control the air supply unit to supply gas to the transparent test chamber to make the transparent test chamber reach the test gas environment. Control the powder supply unit to provide powder materials with a target test mass to the transparent test chamber and form a dust cloud. After a target waiting period, control the ignition unit to ignite the dust cloud in the transparent test chamber with a target test energy, and at the same time control the flame detection unit to detect whether the dust cloud is ignited and the flame temperature and record the data. According to the preset test process, adjust the target test mass, and / or the target waiting period, and / or the target test energy, and repeat the single ignition test steps to determine the minimum ignition energy of the dust cloud.

11. The method for testing the minimum ignition energy of a dust cloud according to claim 10, characterized in that, Adjusting the target test quality, and / or the target waiting duration, and / or the target test energy according to a preset test process, and repeating the single ignition test step to determine the minimum ignition energy of the dust cloud, specifically including: Taking the preset maximum energy as the target test energy, taking the first waiting duration as the target waiting duration, sequentially changing the target test quality according to a preset test quality gradient table to execute the single ignition test step, selecting the test quality with the highest flame temperature and fixing it as the target test quality. If the dust cloud is not ignited under all test qualities in the preset test quality gradient table, then select the maximum test quality and fix it as the target test quality; Maintaining the target test quality, sequentially changing the target test energy by using the dichotomy method, taking the first waiting duration as the target waiting duration to execute the single ignition test step, and determining the first lowest test energy at which the dust cloud is ignited and the first highest test energy at which the dust cloud is not ignited; Maintaining the target test quality, taking the first highest test energy as the target test energy, and respectively taking the second waiting duration and the third waiting duration as the target waiting durations to execute the single ignition test step. If the dust cloud is not ignited, then determine the first lowest test energy as the minimum ignition energy of the dust cloud.

12. The method for testing the minimum ignition energy of a dust cloud according to claim 11, characterized in that, If, when maintaining the target test quality, taking the first highest test energy as the target test energy and taking the second waiting duration as the target waiting duration to execute the single ignition test step, the dust cloud is ignited, then Maintaining the target test quality, sequentially changing the target test energy by using the dichotomy method, taking the second waiting duration as the target waiting duration to execute the single ignition test step, and determining the second lowest test energy at which the dust cloud is ignited and the second highest test energy at which the dust cloud is not ignited; Maintaining the target test quality, taking the second highest test energy as the target test energy, and taking the third waiting duration as the target waiting duration to execute the single ignition test step: If the dust cloud is not ignited, then determine the second lowest test energy as the minimum ignition energy of the dust cloud; If the dust cloud is ignited, then maintain the target test quality, sequentially change the target test energy by using the dichotomy method, take the third waiting duration as the target waiting duration to execute the single ignition test step, and determine the third lowest test energy at which the dust cloud is ignited as the minimum ignition energy of the dust cloud.

13. The method for testing the minimum ignition energy of a dust cloud according to claim 11, characterized in that, If, when maintaining the target test quality, taking the first highest test energy as the target test energy and taking the third waiting duration as the target waiting duration to execute the single ignition test step, the dust cloud is ignited, then Maintaining the target test quality, sequentially changing the target test energy by using the dichotomy method, taking the third waiting duration as the target waiting duration to execute the single ignition test step, and determining the third lowest test energy at which the dust cloud is ignited as the minimum ignition energy of the dust cloud.

14. The method for testing the minimum ignition energy of a dust cloud according to claim 11, characterized in that, In the step of maintaining the target test quality, sequentially changing the target test energy by using the dichotomy method, and taking the first waiting duration as the target waiting duration to execute the single ignition test step, if the target test energy is reduced to be less than or equal to the preset minimum test energy and the dust cloud is not ignited, then Maintain the target test quality, use the dichotomy method to sequentially change the target test energy from the preset maximum energy, execute the single ignition test step with the second waiting duration as the target waiting duration. If the target test energy decreases to less than or equal to the preset minimum test energy and the dust cloud does not ignite, then Maintain the target test quality, use the dichotomy method to sequentially change the target test energy from the preset maximum energy, execute the single ignition test step with the third waiting duration as the target waiting duration. If the target test energy decreases to less than or equal to the preset minimum test energy and the dust cloud does not ignite, then determine that the minimum ignition energy of the dust cloud is greater than the preset maximum energy.

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