Standard Test Method for Minimum Ignition Energy and Quenching Distance in Gaseous Mixtures
气体混合物中最小点火能量和淬火距离的标准测试方法
发布日期:
2013-10-01
1.1本试验方法包括测定点火(爆燃开始)的最小能量和相关平板点火熄灭距离。
2.
完整描述针对在正常环境温度和压力下与空气混合的烷烃或烯烃燃料。该方法适用于指定燃料与空气的混合物,从最容易点燃的混合物到接近可燃性成分极限的混合物。
1.2如果满足某些附加条件,则可以以该方法固有的所有精度扩展到其他燃料氧化剂组合以及其他温度和压力:(
一
)混合物的稳定性以及与炸弹、密封件和其他材料的兼容性通过第节中所述的时间测试确定
9
; (
b
)试验的预期峰值压力在炸弹的额定压力范围内(根据特定研究实验室的要求确定);(
c
)炸弹内的火花击穿与被测距离的Paschen定律一致;
(
d
)温度(包括放电电极的温度)均匀;和(
e
)如果温度不是环境温度,则所需的储能电容小于约9 pF。
1.3该方法是E27委员会开发的几种方法之一,用于确定化学品的危害,包括其在空气或其他氧化剂大气中的蒸汽。这些测量有助于评估由静电或其他电火花引起的燃料可燃性危险。然而,必须非常谨慎地使用淬火距离数据,因为它们主要适用于点火阶段,因此表示初始压力值,而不是较高压力下存在的较小值。
1.4以英寸-磅为单位的数值应视为标准值。括号中给出的值是到国际单位制的数学转换,仅供参考,不被视为标准值。
1.5
本标准应用于测量和描述材料、产品或组件在受控实验室条件下对热和火焰的响应特性,不应用于描述或评估材料、产品或组件在实际火灾条件下的火灾危险或火灾风险。
然而,该测试结果可作为火灾风险评估的要素,该评估考虑了与特定最终用途火灾危险评估相关的所有因素。
1.6
本标准并非旨在解决与其使用相关的所有安全问题(如有)。本标准的用户有责任在使用前制定适当的安全和健康实践,并确定监管限制的适用性。
第5节列出了具体的安全预防措施。
====意义和用途======
3.1最小能量为比较气体的易点燃性提供了基础。平板点火淬灭距离为现有最小点火能量数据提供了重要验证,并给出了各种混合物传播淬灭距离的近似值。强调最大安全实验间隙,如“隔爆”或“爆炸”-
“证明”研究,均小于平板点火熄灭距离。
1.1 This test method covers the determination of minimum energy for ignition (initiation of deflagration) and associated flat-plate ignition quenching distances.
2
The complete description is specific to alkane or alkene fuels admixed with air at normal ambient temperature and pressure. This method is applicable to mixtures of the specified fuels with air, varying from the most easily ignitable mixture to mixtures near to the limit-of-flammability compositions.
1.2 Extensions to other fuel-oxidizer combinations, and to other temperatures and pressures can be accomplished with all the accuracy inherent in this method if certain additional conditions are met: (
a
) mixture stability and compatibility with bomb, seal, and other materials is established through time tests described in Section
9
; (
b
) the expected peak pressure from the test is within the pressure rating of the bomb (established as required by the particular research laboratory); (
c
) spark breakdown within the bomb is consistent with Paschen's law for the distance being tested; (
d
) the temperature, including that of the discharge electrodes, is uniform; and (
e
) if the temperature is other than ambient, the energy storage capacitance required is less than about 9 pF.
1.3 This method is one of several being developed by Committee E27 for determining the hazards of chemicals, including their vapors in air or other oxidant atmospheres. The measurements are useful in assessing fuel ignitability hazards due to static or other electrical sparks. However, the quenching distance data must be used with great prudence since they are primarily applicable to the ignition stage and therefore, represent values for initial pressure and not the smaller values existing at higher pressures.
1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.5
This standard should be used to measure and describe the properties of materials, products, or assemblies in response to heat and flame under controlled laboratory conditions and should not be used to describe or appraise the fire hazard or fire risk of materials, products, or assemblies under actual fire conditions. However, results of this test may be used as elements of a fire risk assessment which takes into account all of the factors which are pertinent to an assessment of the fire hazard of a particular end use.
1.6
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Specific safety precautions are listed in Section 5.
====== Significance And Use ======
3.1 The minimum energies provide a basis for comparing the ease of ignition of gases. The flatplate ignition quenching distances provide an important verification of existing minimum ignition energy data and give approximate values of the propagation quenching distances of the various mixtures. It is emphasized that maximum safe experimental gaps, as from “flame-proof” or “explosion-proof” studies, are less than the flat-plate ignition quenching distances.