Utilizes Emerson’s patented, powerful multivariable
predictive controller (MPC) technology. MPC is the
right technology for the job as the lime kiln has interacting process
variables, long deadtimes, and complex process
dynamics which MPC is designed to handle.
Included is an integral linear optimizer that
moves process variables to economic sweet spots,
while upholding environmental and safety constraints
Scope of the SmartProcess® Lime Solution:
• Multivariable predictive controller
• Lime quality controller
• Kiln economic optimizer
• Operator displays
• Operator training
• MPC tuning displays
• Implementation and commissioning |
Improvement
Highlights
Reduction in Variability:
• Hot-end Temperature - 86%.
• Cold-end Temperature - 82%.
• Excess Oxygen - 90%.
• Specific Energy - 90%.Economic
Benefits
• Reduction in specific energy by 8.5% results
in $935,000 per year in fuel savings.
• Increase kiln throughput
by 22% and improved and improved lime
quality (CaCo3) by 25% resulting in $500,000
savings per year in purchased
lime.
• Reduce Energy and
Chemical Usage: optimize the usage
of steam and cooking liquor.
"We had 4 shifts and
4 different ways of running the kilns. Operators
are now very comfortable with the control, because
they see what is coming and that the controls are working
as designed."
- Production Manager, Large Canadian Mill.
|
The Lime operation is a key unit process in the kraft
mill. Historically, mill operators have run kilns in
manual control, trying their best to meet production rate
requirements while minimizing process upsets. Recently,
rising energy costs and production bottlenecks in the pulp
mill have turned an increased focus on the lime kiln operation.
Emerson's SmartProcess® Lime application minimizes the variability
of the kiln operation and fully optimizes the calcining
process, delivering fuel savings and improved product quality.
