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Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
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Rockwell Automation
Process Solutions User Group (PSUG)
November 14-15, 2011
Chicago, IL – McCormick Place West
Recovery Boiler Combustion control system(CCS) & Emergency shutdown(ESD).
Mario López
Jorge Quesada
Company Profile
Carvajal Pulp and Paper is part of Carvajal Group, a privatelyowned company established in 1904 and headquartered in Cali –Colombia, with over 20,000 employees and annual revenues of overUS$ 1.5 billion from seven sectors and operations in 16 countries:
– Technology and Services
– Information
– Pulp and Paper
– Communication Solutions
– Packaging
– Education
– Espacios
Carvajal Pulpa y Papel is a pioneer in manufacturing paper
from 100% sugarcane fiber
Company Profile
Recovery Boiler
What is the purpose of the Black Liquor Recovery Boiler (BLRB)…?
• Economic – Reclaims chemicals used during the fiber digestion
• Environmental – Closures the process avoiding waste water impact
Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
Caustisizing
Concentrators
RecoveryUnit
Digester
Bagasse Weak BL Strong BL Flue gases
SmeltWater
Green liquorWhite liquor
Pulp
Steam
Recovery Boiler
Recovery Boiler = Chemical Reactor
Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
Source: Black liquor recovery: How does it work? Magnus Marklund
Recovery Boiler
Operation Risks
• Problems of operation and safety exceed those of conventional power boilers
• All details of the smelt-water reaction are not thoroughly understood and fundamental information is still lacking
• Most BLRB explosions have been due to the reactions with molten smelt and water in some form or low solids liquor
• Uncontrolled ignition of an accumulation of unburned fuel from the auxiliary burners/ gases from pyrolyzed black liquor
• Dissolving tank explosions due to excessive and uncontrolled smelt runoff or excessive high density in the dissolving tank.
Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
Recovery Boiler
Process Requirements
• High Availability
• Safe Operation
• Reliability
Main Systems
• Feedwater and condensate
• Air and flue gas
• Black liquor firing
• Auxiliary fuel burning (start up and load increase)
• Soot blowing
Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
Recovery Boiler
Process Control
• CCS: Combustion Control System– Regulatory control: drum level,
furnace pressure, etc
– Discrete control: water pumps,
ID fan, FD fan, etc.
• BMS: Burning Management System– Safe operation of auxiliary fuel
• ESP: Emergency Shutdown Procedure System– Reliable shutdown if water is known or suspected to be
entering the furnace (i.e. leaking pipe)
Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
Recovery Boiler
The need for upgrade…
BLRB data
• Manufacturer: Ahlström-Varkaus
• Design yr: 1972
• Installation yr: 1973
Issues:
• Some failures were hard to fix
• Lack of spare parts for obsolete components
• Reliability could be compromised.
Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
Process Audit
An audit to evaluate the BLRB risk
was conducted…
Identified critical aspects
• System integrity
• Safe operation requirements.
Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
Process Audit
Set a road map with priority levels:
A) To do now: ESP upgrade,
flame scanners and refractometers
B) To plan for soon: BMS upgrade
C) To plan for the future:
CCS upgrade.
Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
Recovery Boiler Challenges
System requirements
• NFPA Regulations– NFPA 85 Boiler and Combustion Systems Hazard Code
– NFPA 86 Furnace and Ovens
• Industry PracticesBLRBAC Black Liquor Recovery Boiler Advisory Committee.
Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
Safety Instrumented System Requirements
BLRBAC Guidelines for Safety Instrumented Systems(1):
There are no specific technology requirements: electronic relays and timers, solid state logic types, programmable electronic systems, hard wired logic or combinations of them.
Applications include:
• ESP, Rapid Drain
• Safe Firing of Black Liquor
• Safe Firing of Auxiliary Fuel
(1) Instrumentation Checklist and Classification Guide for Instruments and Control Systems Used in the Operation of Black Liquor Recovery Boilers.
Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
Safety Instrumented System Requirements
General Recommendations for ESP and Burner Management:
• Requires several features related to hardware robustness:
– Fail safe state on failure
– Non-volatile memory
– Maximum time to read field inputs/initiate action, etc.
• Requires several features related to program integrity and change control
– Password
– On-line modifications not permitted
– No share of any single fault, etc.
Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
• Requirements Applied to ESP:
– Redundant methods or processor to ensure ESP initiation
– Bumpless transfer between processors
– Alternate means of operation or alternate entry points if a digital control system is used (network redundancy accepted)
– Rutinary Backup and auto transfer for processor redundacy testing
– SIS logic state retention should have power from an independent source
• Requirements Applied to Burner Management:
– Conformance to BLRBAC, FM, NFPA, UL, etc.
– Master fuel trip relay / hardwired master fuel trip switch accessible to the boiler operator.
– Trip sequence initiating device indication
Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
Safety Instrumented System Requirements
CCS - Control System Requirements
BLRBAC Guidelines for Recovery Boiler Control Systems (1):
• Fail safe mode
• Firm power source
• Backup system
• Critical loops backup
• Communication redundancy
• Man machine interface
• System security
(1) Instrumentation Checklist and Classification Guide for Instruments and Control Systems Used in the Operation of Black Liquor Recovery Boilers.
Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
Technology Selection
ApplicationLogic
Complexity
I/O
RequirementI/O Count
HMI
RequirementImplementation
ESP Low DigitalLowDI: 20DO:10
Low Hardwired
BMS High DigitalHighDI: 150DO:80
Low Digital Controller
CCS Medium Analog/DigitalHigh
AI:140 / AO:40DI:190 / DO:100
High Digital Controller
Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
Vendor Selection Criteria
Key Aspects to be Considered
• Proven Technology
• Proven Application Knowledge
• Life Cycle Cost (TCO)
– Initial Investment
– Local Support
– Spare Parts Management.
RA proved to provide the best balance of the aspects above.
Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
$$
TechnologyTechnologyApplication Expertise
Life Cycle Cost
Application Expertise
Life Cycle Cost
Upgrade implementation
CCS: Combustion Control System
• PlantPAx
ESP: Emergency Shutdown Procedure Syst.
• Safety relays
BMS: Burning Management Syst. (By COEN)
• PlantPAx.
Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
Rockwell Application
Combustion Control System Architecture
Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
Rockwell Application
CCS and ESP
Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
CCS Redundant Controllers
ESP
Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
Obsolete ESP System New ESP System
Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
DN
2 COMPACT LOGIX
Blowers
Condensated
FLEX I/O
MICROLOGIX
Precipitator
MCC MV
6 nodes
3 MCC LV
66 nodes
2 CLX
Boiler 6
Peripheral
3 CLIENT
BOILER 62 SERVER FT VIEW SE
ETHERNET
CN
B6CLX
Boiler 5
FLEX I/O
FLEX I/O
CLIENT
BOILER 5
CN
CN
B5 PF
S7 Siemens
COMPACT LOGIX
Turbo 1
CLX
Turbo 2
Turbo 2
2 CLIENT
Double Head
Recovery BoilerSERVER
3 REMOTE
CHASIS
REDUNDANT CONTROLNET
REDUNDANT ETHERNET
REDUNDANT CLX
2 SW ETHERNET
StratrixREDUNDANT ETHERNET
BLRB
PANEL ESP
ELECTRIC
CUBICULE
ESP
REMOTE ACCESS
CORPORATE NETWORK
FIREWALL FT-HISTORIAN ASSET CENTRE
REDUNDANT CLX
2 REMOTE CHASIS
REDUNDANT
CONTROLNET
PANEL VIEW 1500BMS
System Integration
Benefits
• Provided Employees with a Safe Work Place
• Improved Operation and Maintenance through Process Integration
• Physical Assets and Business Continuity Preservation
• Customers Satisfaction and Market Presence
• Decreased Cost of Risk
• Decreased Life Cycle Cost.
Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
Conclusions
• Technology is not enough, application expertise is crucial forproject success
• Go digital is not always the best, see if it fits your application
• Take advantage to reduce Life Cycle Costs:
– Initial Investment
– Local Support
– Spare Parts Management
• Negotiate the full package .
Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
Copyright © 2011 Rockwell Automation, Inc. All rights reserved.
Insert Photo Here
Rockwell Automation
Process Solutions User Group (PSUG)
November 14-15, 2011
Chicago, IL – McCormick Place West
Questions
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Mario López
Jorge Quesada