| DENSE MEDIUM SEPARATION: AGRICULTURE | CARROTS POTATOES SUGAR |
Agricultural Applications
ESR International’s
involvement in vegetable preparation began back in 1985
with the largest cannery in Belgium. This cannery had just
about given up all hope of isolating carrots and other root
vegetables from the endless variety of contaminates that
might surround them. Two dynamic effect separators,
followed by a sophisticated color-sorting apparatus,
followed by a group of 20 women, all failed to deliver a
clean product.
The Dense Medium Separation of Root Vegetables
To meet the challenge, ESR
International designed a unique bi-directional dense medium
barrel, and when it was first put in operation at this
Belgian cannery, it was hard to believe the initial
results. Not only did it remove stones and metals from the
carrots, but it also removed near-gravity extraneous
material such as corn stubble, fly ash and bits of plastic.
Even young potatoes that had sprouted from a previous
year's harvest separated out nicely and reported in their
entirety with the stones. Within a few weeks of starting up
this new separator at this cannery, the dynamic effect
separators and the color-sorting apparatus were abandoned,
and the group of 20 women was reduced to two.
The Most Precise Separator in Europe
But the biggest surprise of
all was the precise separation of a good carrot from a
partially dehydrated carrot, or a good carrot from a
low-density defect. Although the difference in density
between a good and bad might be but a few points to the
second or third decimal place, a clear and faultless
separation took place. Here was a separator that performed
20 to 35 times more accurately than the best vegetable
separators on the market. Not only were the maintenance
costs associated with the processing of trash drastically
reduced, but also issues regarding the quality, taste or
texture of the vegetable fell for the first time within the
processor's control.
Fine Sand in
Suspension
In this revolutionary
sorting process, the suspension fines needed to change the
density of water are obtained nowhere else but from the
dirt that mechanical harvesters extract along with the root
vegetables. Two stages of classifying cyclones isolate
ultra-fine sand from the scrub and rinse water of the
pre-processing and cleaning line. In this way, one avoids
the dreadful health issues associated with the use of clay
or sand contaminated with dioxins or heavy metals, and one
avoids as well the thorny environmental and maintenance
issues associated with the use of salt and the disposal of
brine.
Success in
Europe
Eventually 16 bi-directional dense medium separators were
sold in Belgium and France. The leading vegetable processor
in Europe, Bonduelle, with a colossal 30% share of the
European vegetable market, bought five separators. Their
fifth separator, recently installed in August 2004 in
Renescure, France, is the first vegetable separator
designed by ESR LLC that does not employ vibratory screens.
The food giant, Nestle (Sitpa), bought two 60 TPH potato
separators which were installed at its dehydrating facility
in Rosiere, France. With 16 separators in continuous
operation in Europe, some for almost 20 years, it is truly
remarkable that no one to this day has ever been able to
establish a single separation error in the finished
product.
A
Revolution in the Sorting of Carrots
ESR International LLC also
designed for the carrot industry a special scrubber barrel
that rids the carrot of adhering clay and sand. Special
agitators within the scrubber gently scrub the carrots
without breaking them. Typically two separations are
required on carrots. The first separator removes dehydrated
carrots, stones and other high-density debris, while the
second separator removes low-density defective carrots and
debris. Since stones are perfectly removed in the first
separator, conventional stone catchers are no longer
needed, and if stone-catching technology can be abandoned,
so too the gigantic flumes wherein they are conventionally
situated. How much easier it is to transport carrots from
one point to another by means of a simple conveyor belt
than by means of a river of water!
The Frying
and Canning of Potatoes
This technology can push the potato industry in places it
would never dream of going. Never again does the fry market
have to process high sugar content potatoes that discolor
and burn when fried, and never again does the canning
market have to process high starch content potatoes that
slough or disintegrate in a can. Since only those potatoes
that pass the density test are allowed to be processed,
most of the elaborate, sophisticated and costly equipment
needed to identify and eliminate defects after processing
is itself eliminated. Imagine the money that is saved by
not having to fry or can a bad potato, and exciting
possibilities open up of eliminating an entire range of
diseased, bruised, damaged, stressed or improperly stored
potatoes.
Total Control
in the Processing of Potatoes
But if the potato processor can control tuber density to
within a few points to the third decimal place, he can also
apply a level of control far beyond simply eliminating
stones and undesirable potatoes. In frying chip potatoes,
for example, the operator can process at a given time only
those potatoes of a narrow and limited moisture range. In
this way potatoes pass through a frying line at a speed
that precisely matches their moisture content and
therefore, they fry in a thoroughly uniform manner. By
creating two or more categories of low moisture content
potatoes, all the potatoes exiting a frying line are cooked
to the same moisture content and crispiness. Nothing is
undercooked, and nothing is burned.
Likewise, in canning potatoes, the processor should not be
satisfied with eliminating stones and undesirable potatoes
of a high solids content. The operator can make
distinctions between what cans best as whole potatoes and
what cans best as sliced or diced potatoes.
A
Revolution in the Processing of Sugar Beets
With regard to the sugar beet industry, the antiquated
practice of transporting beets by means of a gigantic flume
can be abandoned (since stone-catchers are no longer
needed), and every beet that has gone bad in storage can be
eliminated without sacrificing any of the good beets that
surround them. With this technology, only beets that pass
the density test, that is, only beets of the right sucrose
content, are allowed to enter the diffuser. ESR now offers
to the sugar beet industry a scrubber barrel to rid the
beets of adhering dirt, as well as two dense medium
separators, one to remove stones and other high-density
debris, and the other to remove low-density trash as well
as beets that have deteriorated in storage.
The Key to
the Survival of the Sugarcane Industry in Louisiana
The sugar cane industry in Louisiana is obliged, rain or
shine, to harvest and process the entire cane crop within a
brief 100-day period. Even during the wettest weather, the
billet harvester cannot stop, and consequently it extracts
at times up to 40% extraneous material per ton of billeted
cane. This creates huge losses in production, while
operating and maintenance can increase by over 50%. With
this technology, just about all of this extraneous material
is eliminated, potentially saving each mill in Louisiana
anywhere from $2 to $5 million dollars per season. It is
hard to imagine an industry in greater need of density
separation.
Conclusion
In conclusion, whether we are dealing with carrots or
potatoes, beets or billets, ESR's dense medium process
employing fine sand in suspension can make an enormous
difference. Why process trash? Why process undesirable
vegetables? Why process the right vegetable at the wrong
speed or temperature? Why process the right vegetable for
the wrong market? With this simple and inexpensive
technology, ESR International can put the vegetable
processor firmly in control of the science and art of
giving to his market exactly what it demands.
| DENSE MEDIUM SEPARATION: FOOD | CARROTS POTATOES SUGAR |