ISO 8130-10-2021 pdf free download – Coating powders — Part 4: Calculation of lower explosion limit.
This document specifies a method for the calculation of the lower explosion limit of a coating powder,i.e.the minimum concentration of the coating powder in air which will form an explosive mixture. Itis based on the measurement of the gross calorific value of the product, as determined by the methoddescribed in lSO 1928.
Normative references
The following documents are referred to in the text in such a way that some or all of their contentconstitutes requirements of this document. For dated references, only the edition cited applies. Forundated references, the latest edition of the referenced document(including any amendments) applies.
ISo 1928,Coal and coke — Determination of gross calorific value
ISO8130-14, Coating powders — Part 14: Vocabulary
ISO 15528, Paints, varnishes and raw materials for paints and varnishes —Sampling
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 8130-14 and the following.apply.
IlSO and IEC maintain terminology databases for use in standardization at the following addresses:- ISO online browsing platform: available at https://www.iso.org/obp
一IEC Electropedia: available at https://www.electropedia.org/
3.1
lower explosion limitLEL
minimum concentration of coating powder as a mixture of powder and air, below which an explosion isnot possible
Note 1 to entry: The lower explosion limit is expressed as grams per cubic metre(g· m3).
4Principle
The lower explosion limit of a coating powder is calculated by measuring the gross calorific value viathe heat of combustion of 1 g of product, using Formula ( 1).
An estimation of the lower explosion limit can be made, starting with Formula (2), by multiplying thegross calorific value of each combustible constituent by the mass present in 1 g of product.
5 Sampling
Take a representative sample of the product to be tested as specified in IS0 15528, for use as specifiedin ISo 1928.
6Determination of gross calorific value
Either measure the gross calorific value H of the product under test by the method described inIS0 1928, or calculate it by summation of the gross calorific values of the combustible constituents ofthe product as specified in Clause 7.
NOTE1 With powders that are not flammable, such as those of the poly[(vinyl chloride) type, the calculationmethod can nevertheless give a value for the lower explosion limit in air.Thus, any underestimation of anexplosion risk is effectively avoided.
NOTE 2 The calculation used in this document is based on the following assumptions:a)that material exists in the form of a powder dispersion;
b)that there is complete combustion of the material to the highest oxidation level;cthat there is an adiabatic type of reaction;
d)that the flame temperature for the composition with which the minimum concentration for explosion in air
is attained is 1 oo0c.
7Calculation of the lower explosion limit
Calculate the lower explosion limit, LEL, in grams per cubic metre (g · m3), using Formula (1):
(1)
where
A is a constant equal to -2,5 g/m3;Bis a constant equal to 1,24× 106J/m3;
Hois the gross calorific value of the coating powder, in joules per gram, as per Clause 6.
To estimate the gross calorific value H of the product under test from those of its combustibleconstituents, multiply the gross calorific value of each combustible constituent by the mass present in1g of the product and then summate.ISO 8130-10 pdf download.