Method for detecting explosion risk of aluminum powder

Abstract

The invention discloses an aluminum powder explosion risk detection method, and relates to the technical field of aluminum powder explosion determination. The method comprises the following steps: firstly, installing and debugging a to-be-detected system; secondly, measuring the median particle size of the sample aluminum powder, drying the sample aluminum powder, and putting the dried sample aluminum powder into an experimental tank body; before an aluminum powder explosion experiment, the oxygen content, the temperature and the humidity in the experiment tank body are respectively read; after reading is completed, the experiment tank body is closed, and the experiment tank body is vacuumized to be in a negative pressure state; then injecting a certain amount of air into the vacuumized experimental tank body, pressurizing to a certain value to obtain a turbulence level, igniting through an ignition system, exploding the aluminum powder in the experimental tank body through energy excitation, and recording an explosion pressure through a pressure monitoring sensor; and finally, after an aluminum powder explosion experiment is completed, recording each parameter, calculating an aluminum powder explosion risk index through a formula, and judging a risk level. According to the method, the explosion risk of the aluminum powder can be evaluated more accurately.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum powder explosion determination, and in particular to a method for detecting aluminum powder explosion hazard. Background Art

[0002] Aluminum powder is a recognized high-performance metal material, commonly used in aerospace fuels, propellants and explosives. In the workshops and storage spaces where aluminum powder is produced, it is easy to cause accidental explosions. Faced with the urgent need for industrial protection, it is particularly urgent to prevent and eliminate the risk of aluminum dust explosions.

[0003] At present, the main methods for evaluating the hazard of aluminum powder explosion in the prior art are as follows: Application No. 201910286884.4 discloses a risk assessment method for aluminum powder explosion based on mutation theory. The initial evaluation system is used to conduct a preliminary evaluation of the main influencing factors of aluminum products factories that are affected by aluminum powder explosions, and a preliminary calculation of the main factors affecting the aluminum products factories is performed; then a secondary evaluation is performed through the risk assessment system, and the risk level evaluation system uses mutation theory to construct a hierarchical model, decomposes the evaluation target at multiple levels, and uses a normalized formula to calculate the total mutation membership function value, thereby realizing the factory safety level evaluation and dynamic evaluation. In this method, the evaluation system evaluates the aluminum powder explosion risk twice, and constructs a model to decompose the evaluation target at multiple levels. This method is not only complicated to operate, but also requires the evaluator to master certain model building and calculation capabilities, which is not conducive to timely grasping the hazard of aluminum powder explosion.

[0004] Application No. 202110495125.6 discloses a method and system for predicting overpressure of aluminum powder explosion in a constrained space. By constructing a prediction model for the peak overpressure of aluminum powder explosion, numerical methods are used to study and obtain the influence of different explosion relief surface sizes in the constrained space on the peak overpressure of indoor aluminum powder explosion, and establish a quantitative relationship between the explosion relief surface size and the peak overpressure of aluminum powder explosion inside and outside the constrained space, thereby achieving rapid and accurate prediction and evaluation of explosion overpressure disasters. This method uses numerical methods to study the influence of different explosion relief surface sizes in the constrained space on the peak overpressure of indoor aluminum powder explosion. This method is used in limited scenarios.

[0005] In summary, the above-mentioned prior art predicts and evaluates aluminum powder explosion by means of an evaluation system and by constructing an aluminum powder explosion peak overpressure prediction model, but the method is complex and the prediction accuracy needs to be further improved. Summary of the invention

[0006] The purpose of the present invention is to provide a method for detecting the explosion hazard of aluminum powder. The method uses the characteristics of dust and the environment to directly predict the severity after the explosion. The hazard index F is obtained by directly substituting parameters such as dust particle size, dust mass, ambient humidity, ambient temperature, ignition source energy, oxygen content, experimental tank volume, turbulence, etc. into a formula to analyze and judge the explosion hazard and disaster degree of aluminum powder. The operation is simpler and the evaluation is more accurate.

[0007] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a method for detecting explosion hazard of aluminum powder, comprising the following steps.

[0008] (1) Install and debug the required detection system, which includes an experimental tank, an ignition system, a gas supply system and a data acquisition system. The experimental tank is equipped with an oxygen content monitoring sensor, a temperature monitoring sensor, a pressure monitoring sensor and a humidity monitoring sensor; the ignition system includes a cartridge with different ignition source energies.

[0009] (2) Measure the median particle size of the sample aluminum powder, dry it, and place it in the experimental tank after drying; before the aluminum powder explosion experiment, read the oxygen content, temperature and humidity in the experimental tank through the oxygen content monitoring sensor, temperature monitoring sensor and humidity monitoring sensor respectively; after the reading is completed, close the experimental tank and evacuate the experimental tank to a negative pressure state.

[0010] (3) A certain amount of air is injected into the vacuumed test tank and pressurized to a certain value to obtain turbulence. The air is ignited through the ignition system. The aluminum powder in the test tank explodes after energy excitation, and the explosion pressure is recorded by the pressure monitoring sensor.

[0011] (4) After the aluminum powder explosion experiment is completed, record various parameters and calculate the aluminum powder explosion hazard index F using formula (1).

[0012] (1).

[0013] In formula (1), m is the mass of the sample aluminum powder, T is the temperature in the test tank, U is the turbulence, and V is the volume of the test tank. is the oxygen content in the test tank, E is the ignition source energy, p is the explosion pressure, h is the humidity in the test tank, is the median particle size of aluminum powder, t is the explosion time, e is a natural constant, d is used to represent the differential, dp / dt represents the instantaneous rate at which the explosion pressure p changes with the explosion time t, log 10 D 50 Refers to taking D 50 The logarithmic value of .

[0014] (5) The explosion hazard level of aluminum powder is further determined based on the aluminum powder explosion hazard index F.

[0015] In the above-mentioned method for detecting explosion hazard of aluminum powder, in step (2), the median particle size of the sample aluminum powder is measured by a particle size analyzer.

[0016] In the above-mentioned aluminum powder explosion hazard detection method, in step (2), the sample aluminum powder is dried in a drying oven at a drying temperature of 40 to 50° C. and a drying time of 5 to 7 hours.

[0017] In the above-mentioned method for detecting explosion hazard of aluminum powder, the volume of the experimental tank is 20L.

[0018] In the above-mentioned aluminum powder explosion hazard detection method, in step (5), the aluminum powder explosion hazard level is divided into: when F=0, it indicates that the aluminum powder has no explosion hazard; when 0≤F<10 3 When 10 3 ≤F<10 7 When F≥10 7 , it indicates that the explosion hazard level of aluminum powder is serious.

[0019] Compared with the prior art, the present invention brings the following beneficial technical effects: The present invention proposes a method for detecting the explosion hazard of aluminum powder, which uses the detection system of the present invention to obtain various hazard factors, such as the median particle size D of the aluminum powder. 50 , explosion pressure P in the test tank, oxygen content in the test tank, temperature in the test tank, ignition source energy E, explosion time t, the parameters affecting the explosion hazard are determined through experiments, and the parameters are substituted into the proposed explosion hazard detection method to obtain the aluminum powder explosion hazard index. The larger the F value, the greater the hazard. Through the pressure monitoring sensor and temperature monitoring sensor of the explosion detection system, the pressure and temperature change trend of the exploding aluminum powder during the explosion formation process, as well as the hazard of aluminum powder explosion, can be understood, thereby improving the awareness of operators or experimenters on the hazards of aluminum powder explosion and strengthening engineering prevention and control.

[0020] Compared with the prior art, the present invention obtains the aluminum powder hazard coefficient F through a formula, and by dividing the numerical value of F, the explosion hazard of aluminum powder can be evaluated more accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a flow chart of a method for detecting explosion hazard of aluminum powder. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0023] The present invention proposes a method for detecting the explosion hazard of aluminum powder, which mainly applies the theoretical knowledge of dust explosion, and predicts the degree of danger after the explosion through the characteristics of dust and environment (dust particle size, energy of ignition source, oxygen concentration, dust explosion volume, temperature, relative humidity and turbulence), solving the technical problems of complicated and inaccurate steps in the prior art for evaluating the explosion hazard of aluminum powder. The present invention can obtain the hazard coefficient F through a formula, and by dividing the value of F, the explosion hazard of aluminum powder can be evaluated more accurately.

[0024] The detection system described in the present invention includes a test tank, an ignition system, a gas supply system and a data acquisition system as its main components. In addition, it also includes control valves for controlling the opening or closing of each component. An oxygen content monitoring sensor, a temperature monitoring sensor, a pressure monitoring sensor and a humidity monitoring sensor are arranged in the test tank; the ignition system includes a medicine head with different ignition source energies. The pressure in the test tank is collected by the data acquisition system and saved in the computer. Specifically, for the convenience of observation, an observation window can be set on the test tank; the ignition method of the igniter can be chemical ignition or pulse ignition; the setting of several control valves and the open / closed state can be achieved by those skilled in the art with the help of existing technology.

[0025] The above-mentioned detection system is used to detect the explosion hazard of aluminum powder, which specifically includes the following steps: Step 1, install and debug the required detection system, the detection system includes an experimental tank body, an ignition system, a gas supply system and a data acquisition system, and the experimental tank body is provided with an oxygen content monitoring sensor, a temperature monitoring sensor, a pressure monitoring sensor and a humidity monitoring sensor; the ignition system includes medicine heads with different ignition source energies, and medicine heads with different ignition source energies can meet the ignition source energy requirements.

[0026] Step 2: Use a particle size analyzer to measure the median particle size of the sample aluminum powder, and dry it in a dryer at a temperature of 40-50°C for 5-7 hours. After drying, put it into the experimental tank; before the aluminum powder explosion experiment, use the oxygen content monitoring sensor, temperature monitoring sensor and humidity monitoring sensor to read the oxygen content, temperature and humidity in the experimental tank respectively; after reading, close the experimental tank and evacuate the experimental tank to a negative pressure state.

[0027] Step 3: Inject a certain amount of air into the vacuumed experimental tank and pressurize it to a certain value to obtain turbulence. Ignite it through the ignition system. The aluminum powder in the experimental tank explodes after energy excitation, and the explosion pressure is recorded by the pressure monitoring sensor.

[0028] Step 4: After the aluminum powder explosion experiment is completed, record various parameters and calculate the aluminum powder explosion hazard index F using formula (1).

[0029] (1).

[0030] In formula (1), m is the mass of the sample aluminum powder, T is the temperature in the test tank, U is the turbulence, and V is the volume of the test tank. is the oxygen content in the test tank, E is the ignition source energy, p is the explosion pressure, h is the humidity in the test tank, is the median particle size of aluminum powder, t is the explosion time, e is a natural constant, d is used to represent the differential, dp / dt represents the instantaneous rate at which the explosion pressure p changes with the explosion time t, log 10 D 50 Refers to taking D 50 The logarithmic value of .

[0031] Step 5: further determine the explosion hazard level of aluminum powder according to the aluminum powder explosion hazard index F. The explosion hazard level of aluminum powder is divided into: when F=0, it indicates that the aluminum powder has no explosion hazard; when 0≤F<10 3 When 10 3 ≤F<10 7 When F≥10 7 , it indicates that the explosion hazard level of aluminum powder is serious.

[0032] The present invention will be further described below in conjunction with specific embodiments.

[0033] Example 1: Combination Figure 1 As shown, step 1, before conducting the aluminum powder explosion experiment, design the explosion test plan, determine the different feature combinations in advance, test the energy of the ignition source energy head, ensure that the ignition energy can detonate the aluminum powder, set the ignition delay time, debug the detection system, and ensure that all components are in good condition.

[0034] Step 2: When conducting an aluminum powder explosion experiment, first read the temperature, humidity and oxygen content in the experimental tank after putting the aluminum powder in, then seal the experimental tank, and use a vacuum pump to draw a certain negative pressure into the experimental tank according to the turbulence index.

[0035] Step 3. Open the air inlet switch of the gas cylinder in the detection system, open the control valve, put in a certain amount of air, then close the control valve and pressurize the test tank to a certain value. Under the premise that all control valves are closed, ignite using the set ignition method. When the ignition action is triggered, the control switch of the detection system is turned on, and the test aluminum powder is sprayed into the tank through a dispersed nozzle to complete the injection process. The aluminum powder explodes after energy excitation. At the same time, the data acquisition system is used to collect experimental data such as the maximum explosion pressure and the pressure rise rate. It should be noted that all enclosures containing electrical equipment should be connected to the common ground.

[0036] Step 4: After the aluminum powder explosion experiment is completed, record various parameters and calculate the aluminum powder hazard index using formula (1).

[0037] Step 5: Further determine the explosion hazard level of aluminum powder based on the aluminum powder explosion hazard index F.

[0038] Parts not described in the present invention can be implemented by referring to the existing technology.

[0039] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present application and are not intended to be limiting of the present application. As long as they are within the spirit and scope of the present application, appropriate changes and modifications to the above embodiments are within the scope of protection claimed in the present application.

Claims

1. A method for detecting explosion hazard of aluminum powder, It is characterized in that The following steps are involved: (1) Install and debug the required detection system, which includes an experimental tank, an ignition system, a gas supply system and a data acquisition system. The experimental tank is equipped with an oxygen content monitoring sensor, a temperature monitoring sensor, a pressure monitoring sensor and a humidity monitoring sensor; the ignition system includes a cartridge with different ignition source energies; (2) measuring the median particle size of the sample aluminum powder, drying it, and placing it in the experimental tank after drying; before the aluminum powder explosion experiment, reading the oxygen content, temperature and humidity in the experimental tank through the oxygen content monitoring sensor, temperature monitoring sensor and humidity monitoring sensor respectively; after the reading is completed, the experimental tank is closed and the experimental tank is evacuated to a negative pressure state; (3) A certain amount of air is injected into the vacuumed test tank and pressurized to a certain value to obtain turbulence. The ignition system is used to ignite the air. The aluminum powder in the test tank explodes after energy excitation, and the explosion pressure is recorded by the pressure monitoring sensor. (4) After the aluminum powder explosion experiment is completed, record various parameters and calculate the aluminum powder explosion hazard index F using formula (1); （1）； In formula (1), m is the mass of the sample aluminum powder, T is the temperature in the test tank, U is the turbulence, and V is the volume of the test tank. is the oxygen content in the test tank, E is the ignition source energy, p is the explosion pressure, h is the humidity in the test tank, is the median particle size of aluminum powder, t is the explosion time, e is a natural constant, d is used to represent the differential, log 10 D 50 Refers to taking D 50 The logarithm of ; (5) The explosion hazard level of aluminum powder is further determined based on the aluminum powder explosion hazard index F.

2. A method for detecting explosion hazard of aluminum powder according to claim 1, Features: In step (2), the median particle size of the sample aluminum powder is measured by a particle size analyzer.

3. A method for detecting explosion hazard of aluminum powder according to claim 1, Features: In step (2), the sample aluminum powder is dried in a drying oven at a drying temperature of 40 to 50° C. for a drying time of 5 to 7 hours.

4. A method for detecting explosion hazard of aluminum powder according to claim 1, Features: The volume of the experimental tank is 20L.

5. A method for detecting explosion hazard of aluminum powder according to claim 1, Features: In step (5), the explosion hazard level of aluminum powder is divided into: when F=0, it means that aluminum powder has no explosion hazard; when 0≤F<10 3 When 10 3 ≤F<10 7 When F≥10 7 , it indicates that the explosion hazard level of aluminum powder is serious.

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