cpp – Process technology for the chemical industry 02.2020

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ENVIRONMENTAL TECHNOLOGIES
Decentralised drive systems for process and waste water engineering
Intelligence for pumps,
agitators and mixers
As a drive specialist, Nord Drivesystems uses intelligent and networkable drives
with scalable functions and performance. This concept also offers clear advantages
for pumps, agitators and mixers in process and waste water technology. To some
extent, pumps can organise themselves to ensure reliable around-the-clock operation.
As the demands on the components’ durability are as high as those on their reliability,
the suitability of mechanical design and equipment are of equal importance.
Single-stage Nordbloc.1 helical in-line gear unit with an energyefficient
motor and a Nordac Flex frequency inverter
Pump systems, as well as mixers and agitators,
are elemental components in process
and waste water engineering systems, and
ensure the smooth operation of sewage
treatment plants, waterworks, production
plants, cooling systems or conveyor lines.
They often have to circulate large volumes
of liquid or highly viscous substances.
Therefore, availability, reliability and a long
service life are the top priorities. As a system
supplier, Nord offers fully matched drive
systems consisting of gear unit, motor and
frequency inverter that are tailored to the
respective requirements of the customer application.
Nord drive solutions can be networked,
operate autonomously, and their
functions and performance are scalable. In
the course of the advancing digitalisation of
industrial production, the pump industry is
also moving away from central control towards
decentralised intelligence that controls
processes autonomously, identifies
faults and independently solves problems.
The decentralised drive systems form
master-slave groups that intelligently communicate
with each other, and autonomously
monitor and control the entire
pump system.
Pictures: Nord Drivesystems
PLC performs control functions
The frequency inverter is the brain of the
drive. In decentralised concepts, it is directly
mounted on the geared motor. As standard,
it is equipped with a PLC that can autonomously
perform control functions and reduce
the load on the higher level control
system. Thus, among other things, the frequency
inverter can adjust pressure and
flow rates of the pumped liquids in line
with the actual requirements. In this way,
no excess energy is wasted on valves and
flaps. The frequency inverter perfectly adjusts
the performance to the actual demand,
regardless of whether a fixed setpoint has
been set, or whether it is manually adjustable.
The integration of the PLC into the frequency
inverter enables the Nord drives to record
the drive and pump data (e.g. flow rate,
pressure, pressure difference and temperature),
to evaluate all of the available sensor
and actuator data, to provide optimised
diagnostic facilities and to communicate the
data to the higher level control system or a
cloud solution via the bus system. Continuous
monitoring of the field level and linkage
of communication, sensors (temperature,
current consumption), process data
(torque, acceleration, speed) and vital parameters
of the drive allow for the implementation
of a condition monitoring using
Nord drive systems. This is the basis for a
status-oriented maintenance with the aim of
reducing unscheduled downtimes, lowering
service and maintenance costs, and increasing
the service life of the drives and connected
pumps.
28 cpp 02-2020