7Bucket elevators Capacity calculation Force calculation Mass / meter Sum. resistant coeff.Mat. flowSpeed
8Screw conveyorsTransported materials: material not sensitive to the crunching effect of the screw (ashes, chemicals, fertilizers, food products, meal, ores, paper pulp, salt, sand...)Screw types
9Screw conveyorsFlow direction typesMaterial in the trough
10Screw conveyors Construction Parts: 1 Trough 2 Screw 3 End bearing Section A-AParts:1 Trough2 Screw3 End bearing4 Head bearing5 Hanging bearing6 Drive motor7 Coupling8 Gear10 Feed opening11 Discharge openingPushed or pulled screw?
11Screw conveyors Required power of a horizontal screw: Capacity of a horizontal screw:P = ρhIv(Lf±H) in Wρh= Bulk densityIv= Volumetric capacityL= Horizontal distance of start and end pointsH= Height difference of start and end pointsf= General resistance factor (0,3 – 4,4)Capacity in m3/hDiameter of the screw in mScrew pitch in mSpeed of screw in 1/minFill factorφ=0, high-density, highly abrasive materialφ=0,25 high-density, lightly abrasive materialφ=0,32 low-density, lightly abrasive materialφ=0,4-0,5 low-density, non-abrasive materialk = factor for inclined screwinclinationFor ribbon screws:Max. allowed screw speed exists!k factor
12Screw conveyors Vertical screws Minimal required speed of the screw At critical speedAbove critical speed
13Roller conveyors Transported material: Type of roller elements: different unit loads, such as:boxespalettslong steel or wood materialcomponent assembliesType of roller elements:- Rollers- Wheels (skates)- BallsClassification of roller conveyors:- Gravity roller conveyors- Manual roller conveyors- Powered roller conveyors
14Gravity and manual roller conveyors FixedExpandablevvlimitAccumulation of thetransported unit loadt