Rice Lake Weigh Modules/Mount Assemblies - Manual (Page 3)

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SYSTEM DESIGN
Contents
VESSEL WEIGHING SYSTEM DESIGN
Bulk Material Weighing Systems ................................................................................... 1-2
Custody Transfer ................................................................................................................................................................ 1-2
Material Proportioning ...................................................................................................................................................... 1-2
Loss in Weight ................................................................................................................................................................... 1-2
Common Hopper Scale Arrangements .............................................................................................................................. 1-3
Load Introduction Principles......................................................................................... 1-6
The Ideal... ......................................................................................................................................................................... 1-6
Angular Loading ................................................................................................................................................................ 1-6
Eccentric Loading .............................................................................................................................................................. 1-6
Side Loading ...................................................................................................................................................................... 1-7
Twisting Loads ................................................................................................................................................................... 1-7
Maximizing System Accuracy ........................................................................................ 1-8
Environmental ................................................................................................................................................................... 1-8
Load Cell and Mount .......................................................................................................................................................... 1-8
Mechanical/Structural ....................................................................................................................................................... 1-8
Calibration ......................................................................................................................................................................... 1-8
Operational Considerations ............................................................................................................................................... 1-8
Selecting Number of Supports & Load Cell Capacity ....................................................... 1-9
Number of Supports .......................................................................................................................................................... 1-9
Load Cell Capacity ............................................................................................................................................................. 1-9
Choosing the Correct Load Cell ................................................................................... 1-10
Environmentally Protected ............................................................................................................................................... 1-10
Hermetically Sealed .......................................................................................................................................................... 1-10
International Protection (IP) Rating Guide ...................................................................................................................... 1-11
Calculating Thermal Expansion of Vessels & Stay Rods ................................................ 1-12
Stay Rod Expansion/Contraction ................................................................................................................................................. 1-12
Vessel Expansion/Contraction ..................................................................................................................................................... 1-12
Calculating Tank Volumes ........................................................................................... 1-14
Formulas for Various Tank Shapes and Sections .............................................................................................................. 1-14
Calculation Examples ....................................................................................................................................................... 1-17
Densities of Common Materials ................................................................................... 1-19
Load Cell Bolt Torque Values ....................................................................................... 1-23
Wind and Seismic Effects on Vessel Stability ................................................................ 1-24