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 Thermo
Ramsey's Loss-In-Weight Feeders maintain quality, weighing accuracy,
reduce material waste and improve blend consistency for increased
profits.
The accurate
feeding of a dry bulk material is often critical to maintaining
product quality. A feeder that weighs accurately and reliably
can reduce material waste, improve blend consistency, and increase
profits. Thermo Ramsey?s Loss-in-Weight systems accurately control
the flow of powders, pellets, flakes or granules to critical
processes.
Theory
of Operation
The continuous
Loss-in-Weight principle involves weighing the entire feeding
system (hopper, feeder and bulk materials) by means of a static
type scale system and controlling the discharge feed rate of
the bulk material, by means of a variable speed motor.
Material
is discharged from the system (via screw or vibratory tube or
tray) with the measured ?loss in weight? per unit time (dv/dt)
compared to the desired (set) feed rate. The difference
between the actual (measured) rate and the desired (set) rate
produce a corrective action by the feed rate controller (Micro-Tech
2104), which automatically adjusts the feeder speed, thus maintaining
accurate feed rates with no process lag.
Advantages
of Loss-in-Weight Feeding
- Handles
hot, floodable and difficult materials
- Unaffected
by dust and material accumulation
- Well
suited for low feed rate applications
- Entire
system is weighed. No errors from belt tensioning or tracking.
- No transportation
lag time exists, which assures precision second-to-second
accuracy.
- Feed
accuracy can always be checked during normal operation, without
the need for sampling.
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