Weigh-belt feeders involve a short belt-type conveyor that transports the material from inlet to discharge. Material goes into the feeder and passes through an inlet shear gate, creating a shallow bed of consistent cross-sectional area. The material bed is weighed through the process, and the speed of the belt is continuously adjusted, resulting in a constant gravimetric discharge rate.
Weigh-belt feeders are usually best for medium to high rate applications. Maintaining an accurate and appropriate belt speed is important in weigh-belt feeding. A weigh-belt feeder is capable of highly accurate gravimetric feeding if the weigh-belt feeder is properly maintained.
The accuracy of a weigh-belt feeder depends on the properties of the materials being weighed. Weigh-belt feeders are generally best for handling free-flowing materials, such as powders, granules, pellets. Floodable materials, or materials that are difficult to handle are not well suited for weigh belt feeders. The weigh-belt’s adjustable and relatively unrestricted inlet area allows it to handle materials that are made of larger particle-sizes, such as in primary resin production applications.