|
Gemco Dryers
and Formulators:
Gentle Operation
The tumble action in Gemco vacuum dryers provides gentle handling
of even the most friable and delicate products. The slow speed tumbling
action means that the only forces operating on the product particles
are gravity and the action of one particle on the other. When the
materials slowly cascade down the face of the product bed, they decelerate
against other product before sliding to a stop against the vessel
wall. Once against the heated wall of the vessel, they do not slide
or otherwise erode. They stay there in contact with the wall achieving
heat transfer as the vessel rotates approximately 180 degrees; the
product simply falls away from the wall due to gravity.
Low Temperature
Drying
Vacuum drying allows heat sensitive products to be dried at low temperatures.
The vacuum reduces the boiling point of the liquids involved allowing
them to boil off at lower temperatures as required.
Controlled
Atmosphere
Due to the enclosed nature of the Gemco vacuum tumble dryer, the atmosphere
can be completely controlled. Vacuum removes the vast majority of
the air and oxygen, essentially creating an inert lack of atmosphere
with only the evolving vapors filling the void. When not drying, vacuum
tumble units can be used to control the atmosphere by vacuuming out
the air and oxygen and then bleeding back in an inert gas such as
nitrogen or argon.
Multi-Step, Single Vessel Processing
Gemco vacuum tumble units can be equipped with liquid addition and
moderate shear capabilities to allow single vessel batches to include:
blending dry ingredients; adding a liquid binder to agglomerate the
completed blend; and then drying the agglomerated product to produce
a uniform, free flowing granule.
Produce Less Dense, More Uniform Granules
The one-step Gemco agglomeration system produces less dense and more
uniform granules than the traditional wet granulation method. Wet
granulation produces dense hard materials that then require milling
and higher compaction forces when pressing. The Gemco dust-free granule
method produces consistent density and size range with predictable
good flow characteristics to enter the next processing step. Press
cavity fills are more predictable with more uniform results. The flow
ability of the granules is typically excellent.
Reduced Material
Handling and Paperwork
When several processing steps are combined in one vessel and in one
operation, the product does not have to be unloaded, moved, reloaded
and processed again as often. By removing those extra steps, you can
also eliminate:
- the plant floor
space required for those operations and machines.
- the cleaning
and preparation of the intermediate machines as well as the product
transfer bins and hoppers.
- the trained
labor and maintenance associated with the other machines.
- any associated
process reconciliation reporting and/or paperwork.
Controlled
Worker Exposure
The enclosed nature of the vacuum tumble units combined with their
multi-step processing capabilities greatly reduces material handling
requirements and potentials for worker exposure, spills and accidental
product releases.
Liquid Addition Options
Gemco offers two standard liquid addition options:
- the traditional
atomization through-the-bar liquid addition via the agitator and
its discs;
- the Airless
Spray system with a fixed spray nozzle for greater versatility.
Both work well
in the proper application; and both can be installed on one unit.
The traditional
method of liquid addition is good for adding approximately 5 to 20
percent of liquids with water-like viscosity. As viscosity increases,
the atomization capability of the system diminishes with a resultant
increase in droplet size. Depending upon the product, it can be difficult
to uniformly distribute less than five percent liquid uniformly throughout
a batch via this method. The result is often wet spots and dry spots,
typically not an ideal situation.
The Gemco Airless Spray system utilizes a spray nozzle positioned
in the vessel and aimed directly down at the product bed, thus producing
zero over spray on the vessel walls. It can spray at very slow rates
to uniformly add as little as one percent liquid to an entire batch.
With less liquid added, there is less to remove and processing times
can often be reduced. The Gemco Airless Spray system can control droplet
size independent of viscosity or agitator speed. It can handle any
viscosity or surface tension from Molasses to Mercury. Nozzle sizing
can control liquid droplet size down to micron sizes. Heat traced
lines can be provided to add melted products such as wax.
Add Multiple Incompatible Liquids for Greater Process Versatility
If the process requires multiple series of liquid addition utilizing
different liquids, Gemco can configure a system to have multiple separate
airless spray nozzles with separate lines and delivery systems.
Reduced Waste Streams
With a vacuum tumble unit, the only waste stream is the vapors being
pulled off the product. There is no added air stream or liquid contaminant.
Since the precise liquid addition capabilities of the Gemco units
reduce the amount of liquid binders that need to be added in the first
place, the amount to be removed is correspondingly reduced. Depending
upon their composition, the vapors can be condensed and recovered
or, in the case of water vapor, just allowed to go to atmosphere.
Solvent recovery can be done in a single or two-stage process at vacuum
or atmospheric pressures or both with two condensers. After the condensers,
the remaining exhaust stream can be run to a scrubber, through a charcoal
filter or to an incinerator as appropriate.
Handles Micron Sized Fine Components
Fines are not a problem with the enclosed tumble type processing.
The tumble blending provides excellent dispersion of even the finest
particle sizes without a hang up in filters or on unused surfaces.
Blending is done before applying the vacuum so that there is no issue
of particles caught in the vacuum head filter media. The agglomeration
step (through the liquid binder addition, again before pulling the
vacuum) locks in the blend including the uniformly dispersed fines.
Easy Cleaning
The smooth inside walls and minimal internal components allow easy
cleaning including full CIP operations in some applications. Implementing
Gemco's one-vessel processing capability, combined with the option
of multi-tasking Gemco units, you can eliminate additional machinery,
improve efficiency and also reduce cleaning time.
Reduced Cross contamination Potential
Each process step and material handling procedure offers an opportunity
for cross contamination and/or inadvertent breaks in containment.
Gemco Dryers and Formulators combine these process steps, eliminating
the additional procedures required to perform those steps are gone.
For more information
or to meet with a representative call: 800OKGEMCO (800-654-3626) 732-752-7900
Fax: 732-752-5857 Email: parts@okgemco.com
Web site: www.okgemco.com
Back to newsletter
|
