The feeder pump supplies
the Vacu-Matic with contaminated process liquid from the
dirty tank. This liquid is pumped to the distributor, where it is evenly portioned across
the pool on the filter bed. The bed consists of a flat wire belt supporting the filter media
A Gardner Denver exhauster produces vacuum in the chamber beneath the filter bed,
drawing the liquid through the media and the built-up deposit of solids (filter cake).
When the pressure drop across the filter cake/media reaches a given limit, an electrical
switch is closed. This indexes the media and dried filter cake into the disposal
At the same time, clean filter media is drawn onto the filter bed. Both the vacuum in the
vacuum chamber and the liquid level drop due to the inrush of liquid through the fresh
media. This sudden flow builds the filter cake back to a functional level.
The clean liquid passing through the filter cake and media drains into the clean liquid
compartment of the holding tank. A "water leg" is maintained in the clean overflow
pipe to sustain a vacuum in the filter.
Where excessive floating solids or tramp oil exist in the incoming process liquid, discharge air from the vacuumproducer can be used to operate the standard air skimmer. This moves any loose floating materials toward the dirty end of the filter for removal as media is indexed.
Should the filter bed become flooded due to mechanical malfunction or unexpected impurities in the process, the
liquid level is reduced via the overflow slot connected to the side gutter. This is connected to an overflow drain
pipe dumping into the dirty compartment of the holding tank.
The Hoffman Compact Vacu-Matic
operates using the same principles as the
larger Hi-Flo unit.
The difference is that the Compact has its own clean liquid reservoir, with
dirty liquid often being fed directly to the filter, while the Hi-Flo requires the
storage of all liquids in separate tanks or sumps.
This makes the Compact ideally suited for small to medium sized applications,
particularly in plants where space is restricted. Models are available for flow
rates from 20 GPM (75.7 LPM) to 240 GPM (908.4 LPM). Units are supplied
with both exhauster and pump motors pre-wired to a junction box for easy
The Compact offers all the advantages of flat
bed vacuum filtration:
Removal of tramp oil and floating solids
Coolant aeration to curtail bacterial growth
Continuous coolant flow while indexing
Easy to install, simple to operate controls