Product category:
Flowmeters and Flow Sensors
News Release from: Emerson Process Management | Subject: Rosemount Analytical Oxymitter 4000
Edited by the Engineeringtalk Editorial
Team on 23 February 2007
Flue gas analysis improves efficiency
Rosemount Analytical flue gas analysis products are helping to maintain efficient operations at the major RWE combined heat and power (CHP) plant in Barry, South Wales.
Rosemount Analytical flue gas analysis products from Emerson Process Management are helping to maintain efficient operations at the major RWE npower combined heat and power (CHP) plant in Barry, South Wales This npower Cogen plant supplies electricity, steam and treated process water to the adjacent Dow Corning manufacturing facility
Close monitoring by the Rosemount Analytical Oxymitter of the flue gas oxygen levels is helping to maintain an overall efficiency rate of about 75% for the CHP plant.
This means the plant uses substantially less fuel than conventional methods for generating heat and power.
This efficiency prompted the UK Department for Environment, Food and Rural Affairs to consider the plant a "Good Quality CHP".
The 28MW of generating capacity is developed from two 6.5MW Tornado gas turbines and a 15MW Thermodyn steam turbine.
Multiple high-pressure waste heat recovery boilers and low-pressure boilers also supply up to 250 tonnes per hour of steam capacity to the Dow Corning site.
Rosemount Analytical instrumentation has been well established at the plant, particularly for monitoring the boiler and process water treatment systems.
After recent problems with the existing flue gas analyser equipment, RWE npower installed a Rosemount Analytical Oxymitter 4000 unit on trial.
This zirconium-oxide-based oxygen transmitter is designed to be directly mounted into high-temperature flues.
Its gas analysis measurements are used to fine tune the burner air/fuel ratios for maximum efficiency and reduced NOx emissions.
Following the successful completion of this trial, the plant installed further units.
The Oxymitter 4000 appealed to npower Cogen because its sensor mounts directly into the flue gas duct.
This eliminates the need for a sampling system and avoids the resulting operation difficulties and maintenance.
The Oxymitter 4000 is available with split architecture.
The high-temperature-tolerant probe is mounted directly into the duct and the associated operator and display electronics can be installed up to 60m away at ground level, enabling easy access.
Operators no longer have to climb up through the plant to reach the flue gas head unit to make adjustments or to check the probe.
This eliminates the difficult working conditions and significantly decreases the time spent during inspections and recalibrations.
Paul Gardner, Site Engineer responsible for npower Cogen instrumentation, is pleased with the improved accessibility: "It is far more convenient, and safer, not to have to send engineers right up to the head unit, where access is difficult and scaffolding is required to carry out the work".
"The Oxymitter local operator interface gives us a display of flue gas oxygen level and temperature, and with the sealed push buttons, we can carry out any calibration routines needed on the sensor from ground level".
The Rosemount Analytical Oxymitter's on-line diagnostic determines when calibration is needed and signals a warning on the ground-level display.
This diagnostic routine automatically triggers the sensor monitoring electronics to take an impedance measurement of the cell to detect any drift or contamination.
Any unusual readings trigger a warning on the local operator interface and suggest a recalibration.
The utilisation of Rosemount Analytical flue gas analysis products at the CHP plant coincided with a major expansion of the Barry site in the late 1990s, which involved a GBP 38 million investment by RWE npower.
Dow Corning also invested GBP 200 million at the time to make its site one of the most advanced silicon-based materials manufacturing facilities in the world.
The Dow Corning facility now covers 160 acres and employs approximately 600 people. Request a free brochure from Emerson Process Management ...
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