o Weighing hopper is very important for weigh feeder operation and
performance which helps in on line calibration as well as performance
monitoring.
Measurement Principle of Belt Weigher
o The belt weigher is on line weighing measuring machine used to monitor flow
rate of solid materials.
o There is small load cell weighing assembly mounted in line of belt structure
along with tachometer.
o The weighing assembly measures the weight of the bulk material passing over
it for one-meter span and speed of the belt is calculated with pulse counter
tachometer.
o Flow rate of the material is calculated by measured weight multiplied by
speed of the belt as per serial nos-5.
o The total feed rate is calculated as under:
Flow Rate = Material load unit length of Belt X Belt SpeedFlow Rate in (Tph) = Weight of material (in kg) x Belt speed (in m/sec) x 3600
1000
- To maintain consistency and better performance belt weigher, constant belt
loading (material bed height on the belt) is required over belt. - There is totalizer function which accumulates instant feed rate of material and
gives total figures of flow material as on time. - Accuracy of the belt weigher is approximately ±0.25% of the feed rate is
equipment is well maintained and calibrated with four live load cells. - There are less quantity of dust and weighing assembly is remains neat & clean
and free from dust, foreign particles, - Wear and tear of the equipment almost negligible as compare to weigh feeder.
- The belt weigher is use for monitoring of feed rate but control function is not
possible by the equipment. - Factors affecting the equipment performance:
o The belt should always be in centre of assembly. Drifting of the belt leads to
error in weighing results.
o The deposition of fine material on rollers of weighing assembly also lead to
error in weighing results,
o Uneven feed rate on the belt conveyor affects performance of belt weigher,
o Belt inclination may affect the accuracy of the equipment.
o Condition of belt also affects result of machine,