Overview
ISO 11520-2:2001 - "Agricultural grain driers - Determination of drying performance - Part 2" provides additional procedures and crop‑specific requirements for testing the drying performance of continuous‑flow and batch grain driers. It supplements ISO 11520‑1 (which addresses rewetted wheat in the 20 % to 15 % wet‑basis range) by covering a wider range of moisture conditions and specific crops including wheat, barley, oats, maize, rice, sorghum and rape (canola). The standard defines methods to determine the evaporation rate under steady‑state conditions and to correct drier performance (evaporation, grain flow, drying time, specific energy and fuel consumption) to reference and other ambient conditions. It also specifies sampling and quality assessment procedures for input and output grain.
Key topics
- Crop‑specific procedures: Guidance tailored to the drying characteristics of wheat, barley, oats (including naked oats), maize, rice (paddy, brown, milled), sorghum and rape/canola.
- Evaporation rate measurement: Methods for determining water evaporation during steady‑state drying.
- Performance correction: Procedures and tables for correcting observed evaporation rate, mass flow, drying time and specific energy / fuel consumption to reference ambient and grain conditions.
- Test periods and sampling: Minimum test period definitions (normally at least one residence time for continuous driers or one full drying/cooling cycle for batch driers), sampling frequency, and advice on stabilisation (e.g., allow ~1.5 residence times before measurement).
- Quality assessment: Procedures for sampling inlet/outlet grain to assess moisture removal, grain damage and germination (normative tests for reduction in germination are included).
- Annexes: Normative annexes (C and D) and informative annexes (A, B, E) containing sampling guidance, crop moisture removal data and airflow calculations.
Applications and users
Who benefits:
- Drier manufacturers - product development, performance verification and labelling.
- Testing laboratories and certification bodies - standard test procedures and uncertainty assessment.
- Agricultural engineers and researchers - comparative studies of drier designs and energy efficiency.
- Large farms, grain handling companies and procurement teams - specifying and selecting driers based on verified drying performance and energy/fuel consumption.
Practical uses:
- Comparing continuous‑flow vs batch drier performance for specific crops.
- Correcting field test data to reference conditions for fair comparison.
- Assessing energy efficiency, required airflow and drying time for crop‑specific operations.
- Monitoring post‑drying grain quality (e.g., head rice yield, germination).
Related standards
- ISO 11520-1:1997 - Agricultural grain driers - Determination of drying performance - Part 1: General (reference and baseline methods used together with Part 2).
Keywords: ISO 11520-2:2001, grain driers, drying performance, evaporation rate, continuous-flow driers, batch driers, moisture content, specific energy consumption, crop-specific requirements, grain quality sampling.