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Metalfab Model DBIC (compact) Volumetric Screw Feeder User Manual

Page 2

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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
develop the maximum force available. Under all conditions, the OUTER weights

should be a mirror image of each other and the INNER weights should be a
mirror image of each other.

Any other arrangement could cause damage to the hopper, welds and

the feeder in general.