A screw conveyor is a device used in various industries to feed bulk materials from one part of a process to another. Our screw conveyors can be up to 10 m long. A typical screw conveyor consists of a tubular housing equipped with at least one inlet and outlet spout, one end plate at the drive end to carry end bearing assembly and drive unit. The drive is frequency-controlled.
A screw feeder is capable of delivering dry granular or powder materials with great accuracy at a range of operational speeds. A loss in weight feeder is a gravimetric metering device that receives material from an upstream supply and accurately doses the material into a process.
Loss in weight feeding principle
A feeding device with a hopper containing the material to be fed is placed upon a platform scale or suspension scale weighing system. The bulk material is discharged from the hopper by the feeding device and the resultant weight loss per unit of time is determined by the weighing and control system.
This actual weight loss per unit of time is compared to a desired weight loss per unit of time based upon a desired continuous feed rate set point. When the hopper content reaches a predetermined minimum weight level, the control by weight loss is briefly interrupted and the hopper is refilled. During the refill period, weight is increasing and the controller regulates the speed of the feeding device based upon the historical weight and speed information that was determined during the previous weight loss cycle.
- Short and long term metering accuracy
- Operational information
- Process automation
- Conservation of raw materials
- Reduce product waste
- Improve quality of end product