How to test your gravimetric feeder's performance
Whether you're testing the performance of a gravimetric feeder before or after the feeder is installed in your process, you need to ensure the test method gives accurate results. Read this article for information on defining gravimetric feeder performance, the importance of sampling time, how to establish accurate time and weight measurements, how to take samples, and how to evaluate the test results.
A gravimetric feeder delivers a material by weight at a controlled rate. Two types are available: a weighbelt feeder and a loss-in-weight feeder. The weighbelt feeder is a belt conveyor equipped with a scale and a controller; the scale weighs material as it passes over the belt, and the controller uses the weight information to control the belt speed and, hence, the feedrate, as material discharges from the belt into the process. A loss-in-weight feeder includes a supply hopper, a scale, and a discharge device; the discharge device delivers material from the supply hopper to the process at a rate determined by weighing the material remaining in the hopper.