Metalfab DB2 User Manual

Instructions for Operation & Maintenance

Model DB2 Volumetric Screw Feeder

General Description

The DB2 Feeder is a simple, rugged and accurate, volumetric Feeder
used for the dependable metering of dry solids into process. It
consists of a trough with a metering screw and a variable speed drive,
all mounted on a common base plate.

The large diameter inlet allows for the material flow to the “V” shaped
trough. This helps insure constant pick-up of material and filling of the
metering screw. Hence, accuracy is maintained while rates are varied
by screw speed changes. It is recommended that a bin activator
precedes the feeder when handling new free-flowing materials.

Installation

The DB2 Feeder is shipped complete and ready for operation. There is
no need for bolting the unit into place, however, there are four (4)
tabs positioned at each corner of the base plate to allow the unit to be
bolted for reasons of safety or location. The base should be supported
its entire length to a firm structure. Room should be provided at the
discharge end to allow for screw removal.

Electrical Requirements

Standard units are provided with A.C. variable speed drives with
manually operated controls with indicator located directly on the drive.
They are three phase units requiring 203/460 volt, 60 hertz power.
See separate instructions for A.C. drives. Optional drive is a D.C. drive
with S.C.R. controllers capable of converting alternating current to
direct current. These drives are provided for single phase operation.
See separate instructions for D.C. drives.

Caution

1. Do not change speed of an A.C. drive unless the motor is running.

2. Screw rotation must be clockwise when facing the discharge end of
the Feeder.

Operation

After the unit is in place under the hopper and wired, it is ready for
operation. As noted above, A.C. drives must be in motion to change
speed. Units equipped with D.C. drives can have their speed adjusted
at anytime, i.e., with the unit stopped or in operation. The speed dial
provides for setting screw speeds to 1 part in 1000. Speed is
increased by increasing the potentiometer setting.

Sufficient material should be placed in the hopper and the hand
operated controller dial should be set to #2.5 (#250 for D.C. drives).
The unit should be allowed to run for 5 minutes before a 30 second
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 #2.5, the required rate may then be
obtained by proper speed change. The drive and therefore the feed
rates, are linear, hence, at a setting of #2.5, the Feeder will be
operating at approximately one fourth capacity. Take samples at three
or four settings and a plot graph, setting verses rate. From this graph,
any feed rate may be selected.

WARNING: Keep hands clear of all moving parts. Serious

injury can occur.

Disassembly

Warning: Motor must be electrically locked-out before any
work is performed.

The DB2 Feeder is easily disassembled for cleaning, changing of
screws or maintenance purposes. To remove the screw (Part #1
drawing S-1020):

1. Loosen the set collar on the front bearing (Part #3).

2. Remove bolts on front discharge cover (Part #2) and remove the

cover by pulling it forward until it disengages the screw shaft.

3. Loosen the set screw on the rear bearing (Part #5).

4. Loosen the set screw on the jaw coupling (Part #6) so it will fall

from the screw shaft when the screw is pulled forward.