In-process temperature
monitoring system
for furnaces
eheat processes in the
metals industry greatly
benefit from exact
information about
product temperatures.
The article describes a temperature
profiling system that enters the furnace.
It is used to optimize process efficiency,
validate furnace performance, and verify
mathematical furnace control models.
R
Energy-intensive heat treatment
applications offer great money-saving
potential. One method of choice for steel
manufacturers to optimize productivity
and reduce energy consumption is
in-process temperature profiling. The
following article looks at a monitoring
solution for slab reheat offered by Fluke
Process Instruments.
124
PECM Issue 28
The company, which incorporates the
brands DATAPAQ, Raytek, and IRCON, is
a specialized developer of temperature
measurement and analysis solutions for
harsh industrial applications.
The present system for slab reheat comes
from the tried and tested DATAPAQ
Furnace Tracker family and uses a data
logger that takes regular measurements
from 20 thermocouples attached at various
depths across the length of the slab. While
mathematical models help set up furnaces
for differently sized slabs, measurements
are an indispensable means of verification
for various reasons: environmental factors
may vary over time, steel quality may
differ, and burners may give off heat
unevenly. All these factors influence how
fast and how evenly slabs are heated. In-
process measurements help identify and
correct any furnace or resource problems.
Furnace manufacturers use DATAPAQ
Furnace Tracker systems to validate their
products to customers. Including profiling
trials in their scope of delivery and offering
guaranteed results can even be a selling
point. Steelworks operators use the
systems during furnace commissioning,
when line changes occur, and at regular
intervals to ensure that slabs are heated
to the required temperature all the
way through to the core. The target
temperature range is 1100 °C to 1300 °C.
Beyond the upper threshold, excessive
scale build-up is likely to have adverse
effects on yield and quality. On the other
hand, should the core not be properly
heated, this can damage rollers.