User guide

AccuMeter Controller Chapter 2: Functional Description 19
Lower Mass Flow Weigh Hopper Assembly
The lower mass flow weigh hopper, otherwise known as the weighed common hopper, is used
to determine the actual processing rate of the processing machine so that the blender can be
slaved in to run at the learned rate. The hopper is constructed of spun aluminum and is of the
mass flow type (See the glossary in the Appendix). It is supported by a load cell, and will carry
a weight of material depending on how much is flowing into the hopper from the metering
augers, and how much is flowing out of the hopper, dictated by the processing rate of the
processing machine.
The computer uses the mass flow hopper flow rate (the differential rate), along with the known
total rate from the weight loss feeders to determine the actual processing rate of the processing
machine. The blender output rate is then adjusted to match the learned processing rate. This
method of operation provides very accurate slave in of the blender to the processing rate, and
eliminates the need for a mixing hopper.
The lower common weigh hopper is also equipped with a high level proximity level sensor to
allow manually adjusted volumetric operation of the blender in the event of computer failure.
Figure 4: Weigh Hopper Assembly
Note: The lower or common mass flow weigh hopper uses the change in weight over
time, of material in the hopper to calculate it’s discharge rate (differential rate).
This learned discharge rate is then summed with the known total metering rates
of the blender feeders to learn the actual processing rate of the processing
machine. The blender output rate is then adjusted to match the learned
processing rate, eliminating the need for a blender mixer.