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Delivery: <= 3 days. True-PDF full-copy in English will be manually translated and delivered via email. GB 12476.10-2010: [GB/T 12476.10-2010] Electrical apparatus for use in the presence of combustible dust -- Part 10: Test methods -- Method for determining minimum ignition energy of dust/air mixtures Status: Obsolete
Basic dataStandard ID: GB 12476.10-2010 (GB12476.10-2010)Description (Translated English): [GB/T 12476.10-2010] Electrical apparatus for use in the presence of combustible dust -- Part 10: Test methods -- Method for determining minimum ignition energy of dust/air mixtures Sector / Industry: National Standard Classification of Chinese Standard: K35 Classification of International Standard: 29.260.20 Word Count Estimation: 15,166 Date of Issue: 2010-08-09 Date of Implementation: 2011-08-01 Quoted Standard: GB/T 2900.77; GB/T 2900.79; GB/T 6919-1986; GB 12476.8-2010 Adopted Standard: IEC 61241-2-3-1994, IDT Regulation (derived from): Announcement of Newly Approved National Standards No. 3, 2010 (No. 158 overall) Issuing agency(ies): General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, Standardization Administration of the People's Republic of China Summary: This Chinese standard provides dust and air mixture is ignited spark needed HVDC Determination of minimum ignition energy. This test method is designed to determine the electrical discharge established on combustible dust and air mixture is ignited with a data capacity. This test method does not apply to a recognized explosives, black powder, dynamite, explosive oxy-combustion, spontaneous combustion substances, or under certain conditions, have similar manifestations of substances or mixtures of these substances. GB 12476.10-2010: [GB/T 12476.10-2010] Electrical apparatus for use in the presence of combustible dust -- Part 10: Test methods -- Method for determining minimum ignition energy of dust/air mixtures---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order. Electrical apparatus for use in the presence of combustible dust.Part 10. Test methods.Method for determining minimum ignition energy of dust/air mixtures ICS 29.260.20 K35 National Standards of People's Republic of China Combustible dust Electrical Equipment Part 10. Test methods for dust and air Determination of minimum ignition energy of the mixture of Part 10. Testmethods-Methodfordeterminingminimumignition (IEC 61241-2-3.1994, IDT) Issued on. 2010-08-09 2011-08-01 implementation Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China Standardization Administration of China released Table of ContentsPreface Ⅰ 1 Scope 1 2 Normative references 1 3 Terms and definitions 4 test apparatus 2 5 Test Sample 2 Program 3 6 Appendix A (informative) Example 5 spark generation system Annex B (informative) 9 minimum ignition energy of meaning References 11 Figure A.1 Test Report Form 6 Figure A.2 Determination of minimum ignition energy of dust device (schematic) --- by using a three-pole auxiliary spark discharge system 7 Figure A.3 Determination of minimum ignition energy of dust device (schematic) --- motion by the discharge electrode 7 Figure A.4 Determination of minimum ignition energy of dust device (schematic) --- boost through discharge 8 Figure A.5 Determination of minimum ignition energy of dust device (schematic) --- discharge circuit discharge transformer 8 Table B.1 different types of static ignition capacity of 90,000ForewordAll technical content in this section is mandatory. GB 12476 "combustible dust electrical equipment" is divided into several parts. --- Part 1. General requirements --- Part 2. Selection and installation --- Part 3. combustible dusts exist or may exist Classification of hazardous areas --- Part 4. Intrinsic safety "iD" --- Part 5. Housing protection type "tD" --- Part 6. protective encapsulation "mD" --- Part 7. protective positive pressure "pD" --- Part 8. Test methods for determining the minimum ignition temperature of a dust --- Part 9. Test method for determination of the dust layer resistivity --- Part 10. Test methods for dust and air mixture Determination of minimum ignition energy This section is part GB 1,012,476, equivalent using IEC 61241-2-3.1994 "combustible dust Electrical apparatus Part 2. Test methods - Section 3. a mixture of dust and air minimum ignition energy measurement method "(in English). This part of IEC 61241-2-3.1994 includes the following editorial changes. --- Remove the IEC 61241-2-3.1994 Foreword; --- Increase the national standard foreword. This section of the Appendices A and B are informative appendices. This part is proposed by the China Electrical Equipment Industrial Association. This part of the National explosion-proof electrical equipment Standardization Technical Committee (SAC/TC9) centralized. This part mainly drafted by. Explosion Protection Electric Institute. This part of the main participants. National explosion-proof electrical products for Quality Supervision and Inspection Center, Fushun Branch Coal Research Institute, a positive Explosion-proof electrical Limited. The main drafters of this section. Shu towards Chen in school, Zhang Haiou, Huang Jianfeng, Li Chang recorded. Combustible dust Electrical Equipment Part 10. Test methods for dust and air Determination of minimum ignition energy of the mixture of1 ScopeGB 12476 of the provisions of this part of the dust and air mixture is ignited by a high voltage direct current required minimum spark ignition energy measurement party law. This test method is intended to establish electrical discharge data for determining combustible dust and air mixture whether the ignition capability. Subjects Dust presents state (particle size, moisture content, etc.) should be representative of the actual use, in order to produce the actual dangers to be assessed. The party Determination of the ignition energy can be compared with other dust ignition energy, for assessing the electrical or electrostatic discharge caused by ignition of the respective risk To determine whether the electrical equipment suitable for installation in the presence of combustible dust in the workplace. This test method is not applicable recognized Explosives, gunpowder, dynamite, oxygen-free combustion explosives, spontaneously combustible materials, or in certain conditions With or mixtures of these substances similar forms of substance. If you suspect an explosion characteristics of danger may be a small amount of dust above Placed on the heated surface of the apparatus described in GB 12476.8-2010 heated to 400 deg.] C to obtain indicators. NOTE. should take some measures to protect the test personnel from fire and explosion hazards and/or burning effects, including toxic gas formed by combustion. Consistent with national Standard home does not exempt their share liability. This section includes the relevant Appendix B Electrostatic Discharge minimum ignition energy efficient guidelines.2 Normative referencesThe following documents contain provisions which, through reference in this Part of GB 12476, constitute provisions of this part. For dated reference documents Member, all subsequent amendments (not including errata content) or revisions do not apply to this section, however, encouraged to reach under this section Parties to research agreement to use the latest versions of these documents. For undated reference documents, the latest versions apply to this section. GB/T 2900.77 Electrotechnical terminology for electric and electronic measurements and instrumentation - Part 1. General term measurements (GB/T 2900.77- 2008, IEC 60050 (300-311).2001, IDT) GB/T 2900.79 Electrotechnical terminology for electric and electronic measurements and instrumentation - Part 3. Types of electrical measuring instruments (GB/T 2900.79, IEC 60050 (300-311).2001, IDT) GB/T 6919-1986 air quality vocabulary (eqvISO 4225. 1980) GB 12476.8-2010 combustible dust electrical equipment - Part 8. Determination of the minimum ignition temperature of dust Test Method Method (IEC 61241-2-1.1994, IDT)3 Terms and DefinitionsGB 12476 that this part of GB/T 2900.77, GB/T 2900.79 established in the following terms and definitions. 3.1 Dust dust In the air can settle down on its own weight, but also sustainable solid fine particles suspended in the air for some time. Note. GB/T 6919, the present definition includes "dust" and "grit." 3.2 Combustible dust combustibledust After mixing with air can burn dust. Note 1. combustible dust mixture only within a certain range of concentrations to burn. Note 2. The external source of ignition of combustible dust can be ignited, continues to burn at ambient temperature, but they are only the minimum ignition temperature above its self-combustion. 3.3 Spark discharge sparkdischarge Potential difference exists between the two conductors of electrical discharges moment. Spark is an ion across a gap between two conductors to a single electrical Form passage from discontinuous release. 3.4 The minimum ignition energy (combustible dust and air mixture) minimumignitionenergy (ofacombustibledust/air mixture) Capable of igniting the flammable mixture of air and dust, and it continued to burn spark (measured in accordance with this part of the program) the lowest energy. 3.5 Ignition ignition During the test, when the following conditions be considered when ignited. --- Pressure rises above the sealed container (ie 20L spherical vessel) the pressure measured in the ignition sparks at least 20kPa; or --- Flame tube from the open style (ie. Hartley Man tube Hartmanntube) position sparks occur within the spread at least 6cm. 3.6 Ignition delay time ignitiondelaytime Dust and spray times between the spark discharge occurs.4 test device4.1 spark generating circuit Appendix A lists some suitable circuit form, all of these circuits should have the following characteristics. The following only relates to a circuit. --- Discharge circuit inductance. 1mH ~ 2mH, when the data used to assess the risk of 25μH inductance not exceeding electrostatic discharge circuit when except; --- Discharge circuit resistance (Ω). as low as possible, and not more than 5Ω; --- Electrode material; stainless steel, brass, copper, or tungsten; Electrode diameter and shape. 2.0mm ± 0.5mm. Use spherical electrode to reduce the impact on the corona electrode tip, pointed electricity Can produce extremely erroneous spark energy value. If you use a pointed electrode, the corona impact should be carefully considered. --- Electrode gap. 6mm (minimum); --- Capacitance. low inductance and capacitance, resistance to inrush current; --- Distribution electrode capacity. as low as possible; --- Insulating material between the electrodes. sufficient to prevent leakage current. Note. In general, the minimum resistance for 1mJ minimum ignition energy requirements between the electrodes is 1012Ω, 100mJ minimum ignition energy required minimum resistance To 1010Ω. 4.2 Test container The test vessel is recommended for 20L spherical container or Hartley Man tube. These containers in Ref. [6] and [7] are described. as long as 6.2 meet the calibration requirements, other containers may also be used.5 test sampleThe test shall be carried out on a sample equivalent to actual plant conditions established. The minimum ignition energy with decreasing particle size decreases. test In the test with the actual use shall particle size consistent or finer than the actual use, the sample or the finest material. The ratio should be prepared for the test, the sample through a fixed method, the particle size and moisture content fixed. Note. If the particle size of the material is unknown, the test should be performed on a size of less than 63μm particles. The minimum ignition energy with decreasing particle size decreases. Should check whether the particle size of the sample may appear on behalf of the finest in the factory The particulate material, the test should be performed on a size of less than 63μm particles.6 Program6.1 Description At atmospheric and ambient temperature, the test will be evenly sprayed flammable dust into a suitable device, so that dust and air mixture bear charge Spark capacitor discharge generated. Discharge energy calculated by the following formula. W = 0.5C × U2 Where. W --- stored energy, J; C --- Total discharge capacity, F; The U --- charging capacitor voltage, V. Note 1. When the spark energy than 100mJ, spark resistance will become very small, compared with the spark resistance, circuit resistance can not be ignored, especially when the circuit with 1mH magnitude of inductance coil. In this case, the spark of static energy obtained by the following formula. W = I (t) U (t) dt Where. I (t) --- spark current; U (t) --- spark voltage. Obtained by measuring both. Note 2. For more information spark energy calculation in Appendix A. We need to consider the following factors may have an impact on the test. --- Pneumatic dust and air mixture (ie ignition delay time, spraying pressure); --- Dust concentration; --- Voltage to charge the capacitor; --- Capacitor capacitance; --- Discharge circuit inductance; --- Discharge circuit resistance ([Omega); --- Material and size of the electrode, the electrode gap. To reduce the cost of the test, each test device uses nominal dimensions and the minimum electrode gap electrode containing a specific material. Discharge circuit Resistance should be kept as small as possible (see Chapter 4). Caused by the actual test dust ignition spark energy is beginning to adjust the concentration of dust and dust sprinkled parameters (ie ignition delay time and spraying Pressure), to form the most flammable dust clouds. Use the best ignition timing adjustment capacitor capacitance and/or electric charge it through Pressure, the spark energy gradually reduced by half, until successive 20 tests does not appear until the ignition. NOTE. When using 20L spherical container tested, should adopt the ignition delay time 120ms. The minimum ignition energy between W min 20 consecutive attempts to ignite a mixture of air and dust ignition does not occur and the maximum continuous power W 20 attempts to ignite the lowest energy ignition occurs between W2. W1 \u003cW min\u003cW2 6.2 Calibration Calibration test should be carried out with reference to the three dust. Before measuring, three kinds of dust should be under atmospheric conditions at 50 ℃ dried 24h. The results should be within the following ranges. Lycopodium. W min = 5mJ ~ 15mJ, an average particle diameter of 31 m; Smoke Hua Shi. W min = 2mJ ~ 6mJ, an average particle diameter of 18μm; Polyacrylonitrile. W min = 2mJ ~ 6mJ, an average particle diameter of 27μm. Each sample shall be marked dust spraying parameters including ignition delay time. 6.3 Test Report When tested in accordance with the provisions of this section shall provide test reports, records and information 6.3.3 6.3.1,6.3.2 listed. Although involved Range limits and minimum ignition energy of dust concentration value should be recorded by the laboratory, but divided by the total weight of the dust explosion container values are generally not included In a test report. 6.3.1 Features --- Sample grade (name and chemical species, if the name does not contain); --- Sample source or provenance; --- Sample pretreatment; --- If available, the particle size distribution, moisture content, and characteristics of the data given no pretreatment. 6.3.2 The test device characteristics --- Discharge; --- Explosive containers; --- Dust spray system; --- Total discharge circuit inductance; --- Charging voltage, electrode materials and the optimization of the length of the discharge gap circuit. 6.3.3 Results --- No longer appears in the highest energy W1 ignited; --- Appears when the minimum ignition energy W2. 6.3.4 Report Shape Suitable examples of reporting format shown in Figure A.1.Appendix A(Informative) Spark system example A.1 Overview A.2, A.3, A.4 and A.5 cited with Four spark the occurrence of a circuit diagram of the test. Different explosion container can use these Example, as long as the dust spray to achieve the best, and to take appropriate measures to prevent dust sprinkled over a large container because electrostatic charge phenomenon The boundary effects occur, these phenomena include auxiliary capacitor charging/discharging. If the process of charging the storage capacitor electrode and a state of separation, then when it is connected to the electrode, due to increased capacity and the emergence of Voltage spark energy to reduce impact on the calculation should be considered. In calculating the energy, the total capacitance of the discharge circuit and the voltage should be discharging Be considered. A.2 By using the system to produce a three-pole auxiliary spark discharge The overall arrangement of the test apparatus shown in Figure A.2. The basic element is a three-pole spark gap, wherein the diode is formed having a diameter of 3.2mm main spark arrester (1), over the long After the end of the reduced diameter of 20mm 2mm. End of the auxiliary electrode (2) to the main spark gap is curved, the length of the bent portion 20mm. The electrode arrangement is mounted within Hartley Mann pipe opening, but also suitable for installation in the other explosive containers. Subsequently, the mixture was stirred in the apparatus to a predetermined amount of dust is added, so that the tube in place. High-pressure charger (HVCU), by charging Resistor R has to store ignition energy test capacitance C (20pF ~ 10000pF), the charging current is limited to 1mA. Control device CF discharge try to ignite the mixture of dust and air. Before each attempt to discharge, the discharge is first sprayed into the dust in suspension means After a predetermined time interval, the auxiliary spark discharge through the main spark capacitor discharge test. Energy auxiliary circuit is limited to no more than one-tenth of the main discharge circuit energy. A.3 moving through the electrode discharge The overall arrangement of the test apparatus shown in Figure A.3. Polytetrafluoroethylene stopper block (2) penetrate diode, diode mounting holes in the open type Hartley Man tube (1). With a hole on a stopper block wear Through the electrodes (3), the electrode can be moved. One of them on the ground electrode and the micrometer screw (4) is connected to the spindle, micrometer yoke shortened, Improved clamping de Man Ha tube. Another high-voltage electrode and the only access to the adjustable, pneumatic reciprocating piston (6) (a nominal diameter of the piston 35mm, working pressure of 600kPa) is connected to the lever, operating range of the piston is 10mm, attached to a Teflon insulation (5). A high voltage electrode and the capacitor (7) electrical connection, the capacitance between 26pF ~ 311μF. Charging the capacitor voltage electrostatic voltmeter (8) is displayed. After disconnecting the generator from the high-voltage capacitor circuit (9), from the pressure vessel (10) to electrically - pneumatically releasing air pressure Pressure within the container below the spray pressure of suspended dust. After the timer (11) set delay time, the high voltage electrode incident provisions Location spark gap length, electrical energy stored then released in a spark arrester. A.4 boost discharge (trickle charging circuit) The overall arrangement of the test apparatus shown in Figure A.4. Trickle charging circuit is one of the known energy spark easiest method for manufacturing the most energy for measuring dust and air mixture Small ignition energy. High-voltage DC power supply capacitor potential rises slowly, until a spark occurs. Then repeat the operation generates a series of sparks, each fire The same energy spent. The circuit is equipped with a resistance value of the limiting resistor between 108Ω ~ 109Ω of. Brought coupled with resistance at 108Ω ~ 109Ω series resistance between the electrostatic voltmeter potential capacitance. Using this circuit, by varying the capacitance changes when necessary, discharge Pressure can be easily manufactured in any order of spark 1mJ above. Setpoint before dust loading container determine the energy required to ignite the spark, select the appropriate parameters of the capacitor, the voltage range of 10kV ~ Choose between 30kV. Try adjusting the voltage to the electrode gap and the energy required to spark appeared on the electrode, which is determined by the energy 0.5CU2. Wherein, U is the voltage spark, C is the total capacitance of the high voltage electrode, using conventional AC bridge measurements. For ignition test, High voltage electrode is grounded, the required number of spare dust sprayed into the cup, the DC power into the circuit. When started by the spark electrodes, gas Stream so that dust spray. Record whether ignition, combustion appliances if there is spread from the spark discharge. The first test is usually formed 500mJ high energy spark, if ignited, then gradually reduce the spark energy, repeat the test until 6.1 No provision ignition oc......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of GB 12476.10-2010_English be delivered?Answer: Upon your order, we will start to translate GB 12476.10-2010_English as soon as possible, and keep you informed of the progress. The lead time is typically 1 ~ 3 working days. The lengthier the document the longer the lead time.Question 2: Can I share the purchased PDF of GB 12476.10-2010_English with my colleagues?Answer: Yes. The purchased PDF of GB 12476.10-2010_English will be deemed to be sold to your employer/organization who actually pays for it, including your colleagues and your employer's intranet.Question 3: Does the price include tax/VAT?Answer: Yes. 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