About Batch Loss-In-Weight Feeder

Similar in design to the continuous weigh feeders, Vibra Screw's line of Loss-In-Weight Feeder are capable of batches from ounces to tons, feeding materials from liquids and fine powders to fibrous or flaky materials. Control of batch size and feed time is provided through a unique control package that eliminates the effects of plant noise and the need for traditional vibration dampening devices. Batch accuracy of 1/4 to 1/2% or better can be achieved.

A Loss In Weight feeding system includes a supply hopper or tank, a metering feeder or pump, a supporting scale system, and a microprocessor controller. The system electronically balances tare weight so the controller senses only the weight of the material in the supply hopper.

At time zero, the hopper is full (high weight), and the operator enters the set point or desired feed rate into the controller.

As time and discharge advance, the actual sensed "loss in weight" follows the decreasing scheduled weight ramp whose slope is a direct representation of the desired weight of delivered material per unit of time (set point). The controller makes frequent comparisons of sensed vs. desired rate and alters the feeder's output, keeping it at a set point.

Once the sensed weight reaches the hopper refill level (low weight), the batching controller locks the feed system into volumetric control. The hopper is recharged, and the loss in weight cycle repeats.

The batching controller rate disturbance mode protects against any outside weight disturbance that might cause an upset and provides the unique ability to manually load the hopper at any time without disturbing the feed process.

Quick Change loss-in-weight feeders are specially designed for applications requiring the maximum possible material handling and changeover flexibility.

Materials Fed: Single Screw Loss-in-Weight Feeders: Single screw loss-in-weight feeders handle free-flowing materials such as pellets and powders.

Materials Fed: Twin Screw Loss-in-Weight Feeders: Twin screw loss-in-weight feeders handle more difficult materials such as pigments, sticky, bridging or flooding powders, fiber and fiberglass.