Metalfab Model DBI Volumetric Screw Feeder - Manual (Page 2)

Caution
1. Do not change speed of an AC drive unless the motor is running.
2. Screw rotation must be clockwise when facing the discharge end of the
Feeder.
Operation
After the Feeder is in place and wired, it is ready for operation. Units equipped
with DC drives can have their speed adjusted at anytime, i.e., with the unit
stopped or in motion. The dial provides for setting screw speeds to 1 part in
1000. Speed is increased by turning the potentiometer in clockwise rotation. As
noted above, AC drives must be in motion to change speed.
The hopper should be filled with the feed material and the potentiometer should
be set to #500 (#5 for AC drives). The unit should be allowed to run for 5
minutes before a 1 minute sample is collected and weighed. It is suggested that
5 or more samples be taken to assure the Feeder is operating properly. Once
the feed rate is known at setting #500, the required rate may then be obtained
by proper speed change. The drive and, therefore, the feed rates are linear,
hence, at setting #500 the Feeder will be operating at approximately half
capacity. As an example, if at a #500 setting a 20#/minute rate is achieved and
a 10#/minute rate is desired, change the setting to 250# and a 10#/minute rate
will be delivered. Take samples at 3 or 4 settings and plot a graph, setting
versus rate. From this graph, any feed rate may be selected.
Warning: Keep hands clear of all moving parts. Serious injury can occur.
Optional Hopper Vibrator
The hopper may be equipped with a pneumatically or electrically operated
vibrator if the feed product requires an assist to promote flow. The hopper is
also equipped with a baffle when a vibrator is used. The amount of vibration
should be minimal, just enough to promote flow. The vibrations of the
pneumatic vibrator may be adjusted by changing the P.S.I. setting (pressure
regulator, filter, gauge, etc., by customer), but should not exceed a maximum
pressure of 80 P.S.I. For electric vibrators, the vibrations may be adjusted by
changing the alignment of the centerlines of the eccentric weights.
The closer you align the centerlines of the two (2) OUTER weights with the
centerlines of the two (2) INNER weights, you are INCREASING the force. The
further you misalign the referenced centerlines, the more your DECREASE the
force. If the centerlines of all four (4) weights are completely aligned, you will