Metalfab DBIM User Manual

METALFAB, INC.

P.O. BOX 9 °© PRICES SWITCH ROAD

VERNON, NEW JERSEY 07462

TEL. [phone] * FAX [phone]

INSTRUCTIONS FOR OPERATION & MAINTENANCE

MODEL DB1M (MINI) VOLUMETRIC SCREW FEEDER

General Description

The DB1M Feeder is a simple, rugged and accurate Volumetric Feeder used for
the dependable metering of dry solids into process. It consists of a 1 ft._ hopper
as standard, a trough with an agitator/conditioner screw, a metering screw and a
variable speed drive.

The function of this screw is to keep the material in motion and also "condition"
the material to a constant density while insuring complete filling of the metering
screw flights. Hence, accuracy is maintained while rates are varied by screw
speed changes.

Installation

The DB1M Feeder is shipped complete and ready for operation. There is no
need for bolting the unit into place, therefore, the four (4) levelers positioned
under the base plate are equipped with rubber pads. Room should be provided
at the discharge end to allow for screw removal. Normally, 20" clearance is
sufficient.

Electrical Requirements

Standard units are provided with DC drives which have their own SCR controllers
capable of converting alternating current to direct current. They are single
phase units, 115 volt up to 3/4 HP. The controller may be mounted at the
Feeder location or remotely. See separate manual for controller instructions.

Note: Units with shunt wound motors have the field energized at all times with
the switch in the off position. If feeder is not to be used for an extended period
of time, it is recommended that an AC line switch be installed prior to the control
to power down the control.

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 dialing in the proper speed required.

The hopper should be filled with the feed material and the potentiometer should
be set to #500. 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.

Disassembly

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

The DB1M Feeder is easily disassembled for cleaning, changing of screws, or
maintenance purposes. To remove the discharge tube, loosen the hand nuts
(Part #10, Dwg. S-1902) and pull the tube forward until it disengages the screw.
To remove the screw (Part #1), the tube must be removed as indicated above
then:

1. Loosen the set collar on the reducer (Part #7).

2. Loosen set screw on shaft collar (Part #8) so it will fall from the screw shaft
when the screw is pulled forward.