Volumetric to Gravimetric Feeder Conversions
The purpose of gravimetric feeding is to deliver material at a specified rate of weight flow, matching demand. This is accomplished by multiplying the weight of the material per unit length on the belt (e.g., lbs./sec.). As the weight of the material on the belt changes with density and volumetric efficiency, the belt speed automatically varies to maintain a constant weight feed rate; i.e., as material density increases, belt speed decreases.
The feed rate, representing the feeder output, is then compared to the plant control system demand. The result of this comparison is used to control feeder belt speed.
Features
- State-of-the-art microprocessor controls with self-prompting, self-diagnostic features and automatic belt speed calibration which minimize chances for operator error.
- Direct optical belt travel measurement during calibration which eliminates errors due to belt tolerances and belt wear.
- Barometrically insensitive, load cells which are environmentally sealed, and mechanically protected from shock and overload.
- Extremely low deflection in the dual load cell weigh system eliminates cumbersome weigh platform.
- Maximum weighing accuracy is provided by the material operating load's being a substantial percentage of the full load cell rating.
- Calibration diagnostic features provide a thorough analysis of feeder performance.
What Changes Are Included?
- A new high-center leveling bar.
- An extension to the feeder body shell to contain the load cell assemblies, the weigh roller, and the weigh span rollers.
- A state-of-the-art microprocessor-based electronics package to control belt speed to obtain demand weight feed rate. The cabinet included with this package is mounted on standoff brackets directly to the feeder body shell.
© 2007 Stock - Schenck Process Group
