The case for engineered solutions: Decreasing steam consumption while Increasing machine production, Jorge Trujillo - Product Manager, Paper Industry, Deublin Company Lisa Freed - Manager, Steam and Condensate Systems, Deublin Company - Paper Technology International 2025 FlipBook - Journal - Page 117

The case for engineered solutions: Decreasing steam consumption while Increasing machine production, Jorge Trujillo - Product Manager, Paper Industry, Deublin Company Lisa Freed - Manager, Steam and Condensate Systems, Deublin Company

PAPERTECHNOLOGYINTERNATIONAL
The case for engineered solutions: Decreasing steam consumption
while increasing machine production
Jorge Trujillo - Product Manager, Paper Industry, Deublin Company
Lisa Freed - Manager, Steam and Condensate Systems, Deublin Company
INTRODUCTION:
Historically, paper machine dryer sections have suffered from a range of prevalent inefficiencies, especially in systems with poorly
engineered drainage strategies. These issues stem from flawed design concepts that fail to account for operating conditions.
Among the most critical pain points are:
•
Chronically Flooded Dryers: Main steam sections can
often have chronically flooded dryers, especially at
the ends of the long condensate headers. Even with
oversized headers, end dryers often flood on breaks,
and machine time is wasted because dryer drainage
takes too long to reach steady state after pressure is
stepped up.
•
Water Carry-Over Between Sections: Water carries
over from main section separators and cascades into
the secondary dryer sections, causing flooding and loss
in drying, especially following breaks.
•
Interdependent Steam Sections: On sheet breaks, the
excess of blow-through steam from the main section
is not absorbed by the secondary section, and the
excess is passed to the condenser, which becomes
pressurized.
•
Operational Rigidity: The steam sections do not
correspond to drive sections, meaning that all dryers
must be shut off to cool down any drive section.
•
Pressure Limitations: Secondary sections must operate
at much lower pressures than the main section causing
a measurable loss in drying capacity and preventing
efficient low-pressure operation of the main section
(below about 20 psi).
•
Ineffective Moisture Control: Too many dryers on a
single control result in large thermal inertia and cycling
of reel moisture, especially after breaks. The local
rate of drying is inflexible. Complex cascade systems
remain difficult to operate even with the latest control
strategies.
•
Steam Waste: Large steam waste occurrs despite
anticipated savings from the process because tertiary
sections dump directly to the condenser, and 8-12%
of the total steam is lost, not recoverable, from 昀氀ash
steam residing in high pressure condensate.
•
Poor Operator Experience: Legacy systems are often
disliked by operators due to their rigidity, inefficiency,
and heavy reliance on manual programming or supplier
support.
The Limitations of Early Thermocompressor Systems
Although early thermocompressor-based systems held
promise, initial implementations were fraught with issues due to a
lack of proper technology for system sizing and drainage control.
The key shortcomings included:
1. Ineffective Separators: Separators were inefficient,
and water carried over from the separators seriously
impaired the function of thermocompressor and dryer
drainage.
2. Primitive DP Controls: Standard DP (differential
pressure) controls caused excessive blow-through
flows at low pressure, and much more on breaks. Most
could not operate below 20 psi without wasting steam.
3. Improperly Sized Components: Without advanced
design tools, early thermocompressors were either
undersized and prone to choking or oversized and
uncontrollably inefficient.
A Modern Control System - Deublin’s Blow-Through Control
Blow-Thru Control was developed in response to increased
machine speeds and skyrocketing energy costs. Existing
control systems could not handle these demands, and any new
development would need to rely on system mechanics that had not
been studied before.
Gardner Systems, now a part of Deublin Co., set out to
investigate the real mechanics of steam systems, solving the basic
problems one by one. This led to the development of a simulation
program capable of analyzing and designing dryer steam systems
and ultimately Blow Thru Control.
Deublin Blow-Thru Control maintains a fixed pressure drop
across an engineered orifice plate. It controls a single variable, the
blow-through to condensate ratio, regardless of pressure or speed.
It enables operation across a wide pressure range, responds quickly
to load changes, and reduces the need for excessive differential
pressure. Steam loss is avoided during breaks, and dryer section
header-to-header DP is displayed on the DCS for diagnostics. The
system automatically minimizes steam waste across all conditions.
Under normal operation, dryer section header-to-header DP
varies with dryer pressure, peaking at maximum pressure. During
web breaks, DP drops as blow-through control senses a surge in
blow-though steam upon loss of condensing load, and closes down
the thermocompressor to maintain Blow-Thru setpoint. The dump
valve stays closed.
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