Overview
ISO 17831-1:2015 - Solid biofuels - Determination of mechanical durability of pellets - Part 1: Pellets - specifies a laboratory method to measure the mechanical durability of solid biofuel pellets. Mechanical durability quantifies a pellet’s resistance to shocks and abrasion incurred during handling, storage and transportation. The standard is intended for producers, testing laboratories, equipment manufacturers and purchasers who need reliable durability data for quality control, specification and process design.
Key topics and technical requirements
- Scope and purpose: Defines the test objective, terminology and reporting requirements for pellet durability testing.
- Apparatus (pellet tester):
- Dust-tight stainless-steel rotating box (inner dims ≈ 300 × 300 × 125 mm, wall thickness ~1.5 mm).
- A baffle fixed on the diagonal, rounded edges to avoid cutting.
- Rotation at (50 ± 2) rpm; sample subjected to controlled pellet-to-pellet and pellet-to-wall collisions.
- Sieve and balance:
- Manual sieve with round holes of 3.15 mm diameter (recommended ≥ 400 mm diameter).
- Balance capacity ≥ 2 kg with 0.1 g readability.
- Sample preparation:
- Sampling and sub-sampling per the referenced sampling/sample-preparation documents.
- Minimum sample size 2.5 kg; pre-sieve to remove fines < 3.15 mm.
- Moisture content determination according to ISO 18134 (oven-dry methods).
- Procedure:
- Duplicate determinations.
- Test portion: (500 ± 10) g (500 ± 50 g for pellets >12 mm).
- Tumble for 500 rotations at 50 rpm, then gently sieve (5–10 circular shakes) to separate fines.
- Calculation:
- Mechanical durability (DU) = (mass after tumbling / mass before tumbling) × 100; results to two decimals, report rounded to 0.1%.
- Precision and bias:
- For DU ≥ 97.5%: repeatability 0.3% abs, reproducibility 0.6% abs.
- For DU
Open preview (PDF)Solid biofuels — Determination of mechanical durability of pellets and briquettes — Part 1: Pellets
