Since long before the industrial revolution, manufacturers have
extracted water from local rivers and streams. The process is
still widely used today, in applications from energy generation
to paper making. Unlike their forebears, however, modern
systems inevitably include various treatment processes to
ensure the extracted water meets appropriate quality, safety
and process control standards.
Natural water carries a wide range of materials, all this material can be removed by filtration. But doing that puts additional load on treatment equipment.
nrw Anlagentechnik GmbH, based in Hückelhoven,
Germany, specializes in the production of stainless steel
products for water and wastewater treatment in a wide variety
of municipal and industrial applications. The company has
developed a range of vertical screens that are used to address
one of the key challenges inherent in river water extraction:
solids.
The Bauer gear motors provide compact, robust, and reliable operation, delivering the required low rotation speed
Natural river water carries a wide range of materials,
from algae and plant debris to aquatic fauna. All this material
can be removed by filtration, but doing that puts additional
load on treatment equipment, consumes energy and creates a
waste stream that must then be handled by the operator. Far
better to ensure that such material is prevented from entering
the treatment system in the first place.
nrw Anlagentechnik vertical screens achieve that
objective using perforated stainless steel elements immersed
in the water at the extraction point to prevent solids above a
certain size from entering the water supply. Depending on the
application, the screens use perforations of between 1 mm and
20 mm diameter. To ensure the screens do not become blocked
over time, a system of rotating polypropylene brushes keeps
the outer surface of the screens clear, returning debris safely
and continually back into the water flow.
For many years, nrw Anlagentechnik has specified Bauer
gear motors to operate its vertical brush systems. The Bauer
gear motors provide compact, robust, and reliable operation,
delivering the required low rotation speed – typically less than
2 revolutions per minute – without the need for secondary
powertrain components.
In river water extraction applications, the ability of the motor system to cope with demanding environmental conditions is of paramount importance.
In river water extraction applications, the ability of
the motor system to cope with demanding environmental
conditions is of paramount importance. Not only are the gear
motors mounted in a position exposed to the elements and
just a small distance above the water surface, but in some
installations seasonal fluctuations in the water level can mean
the entire installation is periodically submerged, usually
during seasonal floods.
For these applications, Bauer, part of the Altra Industrial
Motion Corporation, supplies special IP68-rated versions of
its motors, which are fully submersible and impervious to
water and dust ingress. In an installation in South Germany,
for example, the customer specified Bauer geared motors, with
a power rating of 0.12kW. The motors were supplied in the
IP68 configuration, with a special paint finish, fully compliant
with national Water Industry Mechanical and Electrical
Specifications (WIMES).