Chemical Engineering April 2016 - 85

Solids Processing 2016 Special Advertising Section
Perfecting particle size for agricultural chemicals
The Micronizer jet mill from Sturtevant boosts reactivity by grinding particulate materials to
sub-micron sizes - without the heat buildup that can harm sensitive products
M
any chemical
compounds are
highly susceptible
to temperature-related
degradation.
The Sturtevant
Micronizer brand
jet mill reduces
the particle size
of pesticides,
herbicides, fungicides,
insecticides,
and other
dry chemicals to
0.25 μm or larger with
narrow size distributions and
without heat buildup.
The Micronizer employs high-pressure
compressed air, steam or other gas to disThe
Sturtevant Micronizer jet mill (photo)
yields particle sizes down to 0.25 μm. Its
use of fluid energy allows it to out-perform
mechanical grinding systems without
creating undesirable temperature rise.
perse and deagglomerate the particles. It
consistently produces nano-sized particles
whose combined surface area is far greater
than that of larger particles, which increases
their chemical reactivity.
The Micronizer utilizes a unique fluid
energy grinding system to generate particle-on-particle
impact without raising the
product temperature. Activated by highpressure
air, the particles are accelerated
into a high-speed rotation in a shallow
grinding chamber. As the particles impact
on one another their size is reduced.
Centrifugal force holds larger particles in
the grinding rotation area until they have
achieved the desired fine particle size.
Centripetal force drags the desired particles
towards the static classifier where they are
allowed to exit upon achieving the correct
particle size. The final particle size is controlled
by varying the rate of the feed and
propellant pressure. The high-performance
design surpasses the economical fineness
limit of many mechanical grinders.
The Micronizer's open manifold design
allows complete access to the grinding
chamber and compressed air chamber for
easy cleaning, product changeover, or inspection.
There are no dead zones to trap
material, no moving parts to wear, and no
grinding media or lubricants to contaminate
the material being milled.
Sturtevant can solve the most challenging
wear and contamination problems
using interchangeable wear-resistant liners
such as Pureline, ShieldOx, and ArmorLine,
and specially engineered coatings like
Lubriguard, to provide contamination-free
wear protection and enhance the performance
of agricultural chemicals.
The Micronizer can also be found in sanitary
applications such as pharmaceuticals,
nutraceuticals, food ingredients, and biotechnology,
as well as metals, pigments,
coatings and cosmetics.
Sturtevant offers a fully equipped test
facility for conducting customer trials to determine
the optimum equipment and system
layout for each application.
www.micronizer.com
Ultra-high speed powder dispersion made simple
Ross SLIM Technology employs high shear for rapid and complete mixing of powders into
liquids, avoiding agglomerates and dust formation
he Ross Solids/Liquid Injection Manifold (SLIM) is a technology
for dispersing challenging powders like fumed silica, gums,
thickeners and pigments using a specially modified high shear
rotor/stator generator.
In both batch and inline designs, the SLIM is easy to retrofit
into almost any process. In an inline set-up, the SLIM mixer pumps
liquid from the recirculation tank while simultaneously drawing
powders from a hopper. As the liquid stream enters the rotor/stator
assembly, it immediately encounters the powder injection at the
high shear zone. The mixture is then expelled through the stator at
high velocity and recirculated back into the tank. In just a few short
turnovers, solids are completely dissolved or reduced to the desired
particle size.
This method for high-speed powder injection is ideal for dispersing
small concentrations of hard-to-wet solids like CMC or xanthan
gum (>5%). It is equally effective for solid loadings as high as 70%,
as in the case of titanium dioxide or magnesium hydroxide slurries.
By introducing solids sub-surface where they are instantly subjected
to vigorous agitation, issues like floating powders, excessive
dusting and formation of stubborn agglomerates ( " fish eyes " ) are
eliminated. Because the SLIM generates its own vacuum for powder
induction and does not rely on external eductors or pumps, it is free
of clogging and simple to operate.
Several models are available including automated skid packages
where the SLIM mixer is piped to a jacketed tank and supplied with
84
T
Ross Inline SLIM powder
induction mixer with built-in
control panel mounted on a
portable cart with work bench
flowmeters, load cells, solenoid valves, level sensors and thermocouples
all integrated into a PLC Recipe Control Panel. Each ingredient
addition and process step can be pre-programmed so that mixer
speed, mixing time, temperature, composition and batch weight are
accurately replicated in every run.
Established in 1842, Ross is one of the world's oldest and largest
manufacturers of process equipment, specializing in mixing, blending,
drying and dispersion.
www.highshearmixers.com
ChemiCal engineering www.Chemengonline.Com april 2016

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Chemical Engineering April 2016

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