GB/T 16430-2018 Determination of the minimum ignition temperature of dust layer
1 Scope
This standard specifies the specimen, test devices, determination procedure and expression of determination results for determination of the minimum ignition temperature of dust layer.
This standard is applicable to combustible dust that relies on oxygen in the air to maintain its oxidation reaction.
This standard is not applicable to explosives or substances capable of combusting or exploding without relying on oxygen in the air.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 15604 Terminology for dust explosion prevention
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 15604 and the following apply.
3.1
ignition of dust layer
state of the test dust layer when flameless or flaming combustion occurs, or when its temperature reaches 450 °C and above, or when its temperature rise reaches or exceeds the hot surface temperature of 250 °C
3.2
minimum ignition temperature of dust layer
minimum temperature of the hot surface when a dust layer of specified thickness on the hot surface catches fire
Note: Dust exists in a variety of processes, dust layer ignition depends on the actual working conditions, this standard may not represent all process conditions, such as the thickness of the dust layer and ambient temperature distribution and other factors.
3.3
ignition time
time from the beginning of the heating of the dust until it reaches its maximum temperature or appears to catch fire
4 Specimen
Dust specimen shall be made homogeneous and representative. The dust specimen shall be able to pass through a metal mesh or square orifice plate test sieve with a nominal aperture diameter of 75μm. If it is necessary to test with coarser dust, it is allowed that the dusts pass through a test sieve with a nominal aperture of up to 500μm, and the sieve aperture size shall be specified in the test report.
During the preparation of the specimen, any obvious changes in the properties of the dust shall be described in the test report, such as changes caused by sieving or temperature and humidity.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Specimen
5 Test device
6 Determination procedure
7 Presentation of determination results
Annex A (Normative) Structure of hot surface
Annex B (Normative) Measurement of temperature distribution on hot surface
Annex C (Normative) Inference of minimum ignition temperature of dust layer
