ISO 21404-2020 pdf free.Solid biofuels — Determination of ashmelting behaviour.
This document specifies a method for the determination of the characteristic temperatures for the ashmelting behaviour of solid biofuels.
The following referenced documents are indispensable for the application of this document.For datedreferences, only the edition cited applies. For undated references, the latest edition of the referenceddocument (including any amendments) applies.
ISO 16559,Solid biofuels — Terminology, definitions and descriptions
For the purposes of this document, the terms and definitions given in ISO 16559 and the following apply.
shrinkage starting temperature SST: temperature is defined as when the area of the test piece falls below 95 % of the original test piece areaat 550 C (or other ashing temperature used) due to shrinking of the test piece.Note 1 to entry: Shrinkage may be due to liberation of carbon dioxide and volatile alkali compounds. It may alsobe due to sintering and may be a first sign of partial melting.deformation temperature DT: temperature at which the first signs of melting occur.Note 1 to entry: lt is common thatDT will occur shortly before HT/FT.If the test results show a small temperaturedifference between SST and DT and a large temperature gap between DTand HT/FT it is advised that the analystreview the images to verify if the temperature recorded as DT is truly due to melting or if it is a shape changecaused by excessive shrinkage.
Note 2 to entry: Deformation temperature can be seen as rounding of the edges, smoothing of surfaces, expansionof the cylinder or general changing of the cylinder shape. If the test piece starts to swell or bubble without theedges being rounded, the temperature is registered as DT(since swelling and bubbling only occur when a fractionof the ash is melted).Note 3 to entry: For computerized evaluation a shape factor change can be used to define the deformationtemperature.For definition of shape factor see Annex A.ISO 21404 pdf download.