About the weight feeder and loss-in-weight feeder

As the name suggests weight feeder, the unit measures a loss in weight over a certain period of time and adjusts the feed mechanism output accordingly.

A typical accuracy statement for a loss-in-weight feeder specifies repeatability as a percentage of the sample-size at a given statistical confidence level.Compared to the feeding time, the refill time needs to be as short as possible to maximize the percentage of time the feeder is under gravimetric control.

Loss-in-weight feeders require periodic refill from an external device such as a screw conveyor, bin activator, pneumatic conveyor, slide gate valve, or rotary valve.

A loss-in-weight feeder consists of three components: a scale with a dedicated controller to weigh material; a feed mechanism (screw, vibrating tray, etc.) with a variable-speed drive to introduce material into the process; and an integral weigh hopper for material storage.