AUTOMATION & PAINT ROBOTS
Custom engineered continuous shot blast machine for the production of bright steel products
Descaling of 14 tons of
drawn steel bars in one hour
Drawn steel, also
known as bright steel,
for example used in the
production of diesel
injection components,
must meet strict
quality standards.
A key stage in the
manufacturing of
drawn bright steel is
the blast cleaning of
the raw material
prior to the drawing
process.
Recently, Rösler
developed a
continuous shot blast
system for a leading
manufacturer allowing
the fully automatic
blast cleaning of steel
bars with diameters
/cross-sectional
dimensions of 24 up to
80 mm (approximately
1.0 – 3.2 inches).
This system not only
produces excellent
descaling results but
permits processing
speeds of up to
60 meters (197 feet)
per minute.
Blast cleaning – a critical step in
the overall manufacturing process
Prior to being drawn into steel bars with
standard round, square and hexagonal profiles
as well as steel bars with special profiles, the
rolled steel must be blast cleaned to remove
scale and rust from its surface and a key factor
for the excellent quality of the drawn steel
products. Other factors for the high quality of
these products are the comprehensive knowhow
and state-of-the-art manufacturing lines for the
drawing, peeling/stripping and heat treatment
processes. Blast cleaning is highly critical for
meeting the specific customer requirements for
an absolutely homogeneous surface as residual
scale on the steel can damage the drawing die
which causes scratch marks on the drawn steel
product and scale embedded in the drawn steel
can damage the tools during the subsequent
machining process. For this reason, after the
blast cleaning process the surface of the rolled
steel must have a degree of cleanliness of SA
2,5 – SA 3.
In addition, customer specifications call for a
high component throughput, high equipment
availability, ease of maintenance and a highly
efficient dust collection system.
Designed for a high capacity
The REDL 6-30/100 allows the blast cleaning
of steel bars with round, square and hexagonal
profile and cross sectional dimensions from
24 to 80 mm (approximately 1.0 to 3.2 inches).
The transport of the steel bars takes place on
transport rollers made from annealed tool steel.
In the case of “light weight” components,
special pressure rollers prevent the bars
from slipping. The processing speed can be
individually adjusted to the components being
processed within a range of 12 – 60 m (39 –
197 feet) per minute. This ensures that even
in the case of steel bars with extreme rust
and scale on their surface (rust grade “C”)
a cleanliness of SA 3 can be achieved without
difficulty.
The Rösler blast machine is equipped with
6 high performance blast turbines, each with
an installed drive power of 30 kW.
50
May 2014
The critical parts of these turbines are made
from wear resistant materials like hardened
tool steel and manganese steel. The housing
is made from interlocking laser cut parts
resulting in a highly robust design with a high
life expectation. The throwing blades eliminate
the need for fixing bolts and springs.
The new Rosler shot blast system is so
productive that in many cases customers
are reporting that it has practically doubled
their shot blast capacity with the blast cleaning
process now being significantly faster than
the drawing operation. They can now place
the blast cleaned steel bars into a special
buffer stock which allows them to turn off the
shot blast machine for several hours per day.
This not only helps to reduce their energy
costs but also their reduced requirements for
wear parts and blast media. Now they also
have a welcome capacity reserve in their shot
blast operation.
Optimum protection against wear
Two turbines offset by 60° are strategically
placed in each of the three blast chambers in
a manner tha [