ISO 7189:1983 - Apron conveyors - Design rules
Overview
ISO 7189:1983 establishes design rules for apron conveyors - continuous mechanical handling equipment used to transport both loose bulk materials and unit loads. Published by ISO/TC 101, the standard provides symbols, units, formulas and tables needed for the mechanical design and capacity calculation of apron and pan-type conveyors (including conveyors with curved or flanged plates and closed pans). It is intended as a technical reference for sizing, resistance and power calculations for apron conveyor systems.
Key topics and technical requirements
- Scope and nomenclature: Definitions and reference to related nomenclature (ISO 2148).
- Symbols & units: Standardized designations for pitch, width, filling volume, density, chain pull, speed, etc.
- Flow and capacity calculations:
- Volume flow rate qv = v × A (conveying speed × filling cross‑section).
- Mass flow rate qm = ρ × qv (density × volume flow).
- Unit‑load flow qst = v / ast (speed divided by average spacing).
- Filling cross‑section and filling factor: Theoretical pan filling geometries (triangles/rectangles) and a filling factor φ (typically 0.5–1) to account for incomplete/irregular loading.
- Slope effects: A reducing factor k (table values from k = 1.00 at 0° to k ≈ 0.71 at 24°) adjusts filling volume for incline/decline conveyors.
- Resistance components:
- Slope resistance, main (operational) resistance, secondary (chain/chain‑wheel) resistance, and special resistance (material against skirtplates).
- Artificial friction coefficient f and bearing friction j values are tabulated for design (examples: plain bearings f ≈ 0.08–0.10; rolling bearings f ≈ 0.02–0.03).
- Chain pull and dynamics: Total chain pull includes peripheral drive force, slope resistance, initial tension, and dynamic polygonal effects (Fdyn). Guidance on limiting dynamic pull via small chain pitch and moderate angular speeds.
- Power & drive sizing:
- Driving power PA = Fu × v (peripheral force × speed).
- Motor power accounts for transmission efficiency (PMot = PA / ηges).
- Recommended operating speeds: Typical ranges given (e.g., 0.6–0.8 m/s for many flat‑link chains; up to 1.2–1.5 m/s for some round‑link chains; unit‑load conveyors often ≤ 0.4 m/s).
Applications and users
Who uses ISO 7189:
- Mechanical design engineers and conveyor manufacturers
- Plant engineers in mining, quarrying, cement, bulk‑material handling, ports, power plants and heavy industry
- System integrators and consultants sizing apron conveyors for material flow, power and structural requirements
Practical uses:
- Sizing pans and chain selection, estimating capacity and mass flow
- Calculating friction, slope effects and required drive power
- Ensuring reliable operation (preventing chain slack, limiting dynamic loads)
Related standards
- ISO 2148 - Continuous mechanical handling equipment: Nomenclature (referenced by ISO 7189)
Keywords: ISO 7189:1983, apron conveyors, design rules, continuous mechanical handling equipment, filling cross section, volume flow rate, chain pull, driving power, bulk materials.
