Self-cleaning process

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Self-cleaning process
Dateiname: CZHK1338Sp_Rematec_englisch Druckdatum: 20.09: 09 Photo credits: Rematec (1), Zeppetzauer
Thema > Special
Short distances: Mill and screen conveyor can be accommodated in a space
of a few meters – at the table to the right, results can be analysed immediately
Rematec‘s management team pictured with the new RPM 650: Robert,
Elke and Ulrich Steiger, Helmut Lukes (from the left)
REMATEC
Self-cleaning process
Prevents annoying blockages with screen conveyor
The pelletizing process requires a careful prior treatment of the raw material. To
prove that this does not necessarily use a lot of space nor power but rather prevents shutdowns due to clogging, Rematec has presented a new concept. Apart
from a wet hammer mill it features screen conveyors and leads to immediate
improvements.
A
treatment plant is like a construction set: At
the center there is the hammer mill 650 RPM
which can process sawmill by-products up to 55%
humidity. One step prior there is the feed hopper
of the raw material, one step thereafter the chip
bunker. In between, the chips have to be screened so that they will go through the belt dryer as
a homogeneous chip cake. The crux of the whole
process is best explained by Rematec project manager Helmut Lukes: „Some shredding lines use
oscillating or sliding screens which not only requi-
re a lot of space but also do not fulfill transport
functions.“
From small to large
The experts from Lower Bavaria have come up
with a solution that had to offer real benefits to
customers. At the same time, throughput and sieving performance could not be compromised. The
solution they presented is as simple as it is ingenious: a screen conveyor. In short, the small particles fall through the screen holes located at the
5. Refeeding of rough
fraction into mill
4. Screen conveyor after the milling:
Rough and fine fractions form
1. Input: Rough and fine particles are mixed
3. Processing in the
friction plate mill
bottom of the metal tube. The rotating screw pushes the long particles along the tube and ejects
them through an outlet. The screen conveyor has
yet another advantage: The rotation movement
ensures that the holes are cleaned constantly. This
prevents any blockage within the system which
in turn significantly increases its availability. One
might think that this concept has reached production maturity only for small plants. But make no
mistake: One of Rematec‘s prominent customers,
pellet plant I. van Roje, Oberhonnefeld/DE, with
an annual capacity of 40,000 tons, already has this
system in place. „Large capacities do not pose an
obstacle for our concept. Nothing is easier than
to install a twin-screw, for example“, says Lukes.
Compact designs are in high demand nowadays,
because: „Not only machines constantly undergo
optimizations. Also the space requirement is analyzed in some companies“, he adds.
Fully up to customers‘ expectations
The experts from Lower Bavaria estimate that
10% of the remaining particles qualify as extra
large. These are once more fed to the friction plate mill. An automatic control unit keeps an ideal
screw filling rate of 30%. Customers can choose
from a multitude of screens depending on their
requirements. The screen conveyor can be placed
right before or after the mill in order to filter out
dust and excess lengths.
„Some customers think: Why should I unnecessarily increase the volume of the chip cake within
the system?“, says Lukes. The first concept planning stage begins at the table next to the pilot
plant in Dietersburg. If the customers then hold
their processed material in their own hands, the
first ice is already broken. More often than not,
this „hands-on“-effect has already helped to bring
some successful deals to life. CZ ‹
2. Screen conveyor prior to
the milling process: Rough
and fine fractions form
FACTS & FIGURES
REMATEC
6. Output: Fine fraction for
further processing
The scheme of chip purification: The screen conveyor can be installed either before or after the hammer
mill
Established: Location: Employees: Management: Category: 2004
Dietersburg/DE
50, including 7 trainees
Robert Steiger,
Ulrich Steiger
machinery and equipment
(waste wood processing,
conveyor systems, screens,
hammer mills), pelletizing
H O L ZK U R I E R 0 0 • T T. M M . JJJJ
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