Facts & Figures Book - KPI-JCI

FLOWABILITY—ANGLE OF SURCHARGE—ANGLE OF REPOSEVery freeflowing Free flowing Average Flowing Sluggish5° Angle of 10° Angle of 20° Angle of 25° Angle of 30° Angle ofsurcharge surcharge surcharge surcharge surcharge0°-19° Angle 20°-29° Angle 30°-34° Angle 35°-39° Angle 40°-up Angleof repose of repose of repose of repose of reposeMATERIAL CHARACTERISTICSUniform size, Rounded, dry Irregular, granu- Typical common Irregular,very small polished particles, lar or lumpy materials such as stringy, fibrous,rounded particle, of medium weight, materials of bituminous coal, interlocking mateeithervery wet or such as whole medium weight, stone, most ores, ial, such as woodvery dry, such as grain or beans. such as anthra- etc. chips, bagasse,dry silica sand, cite coal, cotton- tempered foundrycement, wet con- seed meal, clay, sand, etc.crete, etc.etc.d. The material weight affects the volume, which affectsthe width. Most aggregate weighs between 90-110 lbs.per cubic foot. When the weight varies significantly, it canhave a dramatic effect on expected belt width needed toachieve a given tonnage.5. HP RequirementsThe power required to operate a belt conveyor dependson the maximum tonnage handled, the length of the conveyor,the width of the conveyor and the vertical distancethat the material is lifted. Factors X + Y + Z (from tablesbelow) = Total HP Required at Headshaft. The figuresshown are based on average conditions with a uniformfeed and at a normal operating speed. Additional factorssuch as pulley friction, skirtboard friction, material accelerationand auxiliary device frictions (mechanical feeder,tripper, etc.) may require an increase in horsepower.Drive efficiency is taken into consideration to determinethe motor horsepower required. This can be an additional10-15% above the headshaft HP. The ability to start aloaded conveyor will also require an additional HP consideration.Material Handling191