Transcript TDLS Applications

INTRODUCTION
OPSIS is a Swedish company which develops, manufactures
and supplies total solutions for Ambient Air Quality Monitoring, Stack
Emission Monitoring and software tools for Air Quality Management.
Founded 1985
OPSIS is represented world-wide, with internationally accepted and
approved products.
OPSIS PRODUCTS
MAJOR APPLICATION AREAS
QUALITY AND ENVIRONMENTAL
MANAGEMENT
ISO 9001
• Quality
ISO 14001
• Environment
ISO 17025
• Calibration laboratory
• Ackreditation laboratory
OPSIS CEM SOLUTIONS
CEM/PROCESS SOLUTIONS
UV/IR DOAS IN-SITU SYSTEMS
TUNEABLE DIODE LASER IN-SITU SYSTEMS
DILUTION EXTRACTIVE SYSTEMS
LASER DIODE ANALYSER
Features :
• Fast response time (~ 1 sec)
• Multiple paths
• Multiple gases
• Analyser separated from Emitter/Receiver
• Long fibre lengths (< 1 km)
• Low detection limits
SYSTEM OVERVIEW, CEM
LD500
EM060L
Cabinet
Laser fibre optical cable (< 1 km)
Communication cable (< 2 km)
RE060L
Emitter
Receiver with detector and A/D converter
SYSTEM DESIGN
Stack
Digital signal
LD500 analyser
Ramp generator
Diode laser
Beam splitter
CC
Communicatin Interface
”Measurement” signal
Reference cell
Internal Detector
PC
Beam switch
”Zero” signal / ”Reference” signal
Wavelength/scanning control signal
LD500
Processor
TUNING THE LASER
Δλ
ΔT
NIR semiconductor laser
Controlled variations in temperature will ”tune” the diode lasers output
wavelength.
The temperature variations are created by applying a sinus shaped drive current
with a frequency of 1 kHz, with a temperature accuracy of 0.001 C˚
ABSORPTION SPECTRUM
Laser is tuned around one or a few absorbtion lines,
Scanned range is typically less than 1 nm
Absorbance
100%
O2
HF
H2O
0%
1.25 um
LD500
1.35 um
SPECTRA HANDLING
”Zero” signal
”Measurement” signal
Resulting spectrum
The scanned spectra are resolved into 1000 channels
Measurement spectrum is divided with the Zero spectrum to obtain the
resulting spectrum and to eliminate noise generated by the laser
EVALUATION
I1
I2
C=
Ln ( I1 / I2 ) x l
α1 – α2
+ Line Widening effects due to
temperature & partial pressure
The cross section
area of the obtained
spectrum is used to
calculate the
concentration by
use of Beer
Lamberts law,
compensated for
line widening
effects
RESULTS
Results are presented as :
Concentration ( typically % (vol) , ppm or mg/m3 )
Standard deviation ( typically ppm or mg/m3) , based on the
average standard deviation over the evaluated number of
channels in the measured cross section spectrum
Light level, expressed as dB , proportional to the
amplification required on the detector.
MEASURING TEMPERATURE
Absorption lines
Temperature can be measured by studying the proportions and relations
of the absorption lines, as they change with temperature
HARDWARE
•Central Unit
•Incl.
-Laser Head
-Keyboard
-Modem
-IO 256
-RS 232
-Protocol for PLC
EMITTER
RECEIVER
PERFORMANCE
Gas
Typical
Range
Detection
limit
( 10 metre)
CO2
0-100%
0.01%
CO2
0-10000 ppm
0.5 ppm
O2
0-21%
0.01%
H2O
0-100%
0.01%
CO
0-100%
0.01%
CO
0-10000 ppm
10 ppm
CH4
0-100%
0.01%
CH4
0-10 000 ppm
0.2 ppm
NH3
0-1000 ppm
0.05 ppm
HCL
0-1000 ppm
0.05 ppm
HF
0-50 ppm
0.005 ppm
Temperature
0-1500 ° C
+/- 5 ° C
CEM/PROCESS EXAMPLE
(maximum 8 paths )
SIGNAL LAYOUT
Emitter
Receiver
A/D
+/-15 VDC
+6 VDC
Optical fibre
cable
110/220-240 VAC
Communication
fibre cable
RS232
Hard Disk
Laser Module
Laser Module
Laser Module
LH51n
Multi
Channel
Multi
Analysing
Channel
Multi
Module
Analysing
Channel
Module
Analysing
CC002Module
+/- 15VDC
Computer
PC104
Floppy Disk
PM020
LCD
CM002
110/220-240 VAC
DM016
IM001
OM001
Keyboard
Modem
0-10VDC
0/4-20 mA
0/4-20mA
Ioman Signal Handling System ( Optional)
24 VAC
+/- 12VDC
+5 VDC
LD500 Analyser
110/220-240 VAC
Status
I/O
CO , CO2 , H2S
LH 514 Laser Module
Typical Applications:
• Process monitoring
•Tunnel monitoring
•Steel plants
•Cement plants
O2 AND TEMPERATURE
LH 515 Laser Module
Typical Applications:
• Furnace control
• Steel process
• Smelters
• Incinerators
HCL
LH 512 Laser Module
Applications:
• Waste Incinerators
• Chemical industry
• Acid Scrubbers
NH3
LH 513 Laser Module
Applications:
• DeNOx Applications
• Fence-line monitoring
• Fertilizer industry
IPP-TAIWAN: 20 g/m3 dust , 300 degrees C, 4 metre path
ER60L-Receivers
Power supply for detector
ER60L-Emitters
CH4
LH 516 Laser Module
Applications:
• Petrochemical plants
• Coke ovens
• Landfill
HF
LH 511 Laser Module
Applications:
• Aluminium smelters
• Fence line monitoring
• Chemical industry
POTROOM MONITORING
EXAMPLE , HF DATA
Pot activities
CALIBRATION
Calibration cell
Receiver
Standard gas
Emitter
Calibration bench
Analyser
LD500
CALIBRATION EQUIPMENT
Rotameter
(flow control)
Calibration
gas
Receiver
Emitter
Calibration bench Gas valves
LD500
COMMUNICATION ALTERNATIVES
Plant DSC/PLC
RS232, Alternative 4 ( Cactus, ABDH, ModBus, Siemens 3964R, Comli)
Enviman ComVisioner
RS232, Alternative 3
Analyser
LAN
RS232
RS232, Alternative 2 +3
RS232, Alternative 1
+/- 15VDC
CM
IM001
OM001
0-10VDC
0/4-20 mA
0/4-20mA
DM016
110/220-240 VAC
Ioman Signal Handling System ( Optional)
Status
I/O
STEEL PLANT APPLICATIONS
EMISSION MONITORING
Vizag steel plant Visakhapatnam,
India,using Opsis analysers for
monitoring NOx and SO2 in 15
stacks
REHEATING FURNACE
• Purpose
– Used by all steel processing plants to heat material
before treatment
– Often crucial to meet right temperature
– Can replace soaking pit
• Operation
– Oil- or gas burners heat the oven compartment
– Desire to use natural- or waste gas
– Comparably low dust level
REHEATING FURNACE
• Measurements of interest
– Oxygen : decrease level to reduce fuel consumption
and oxidation but keep sufficient levels for effective
combustion
– Carbon Monoxide: as indicator of incomplete
combustion
– Temperature: Important for correct process
• Problems to overcome
– Tendency of smoke formation at low oxygen levels
– Hot environment
MONITORING AFTER REHEATING FURNACE
AR600 ( NO,NO2,NH3)
LD500 ( O2)
TAIL GAS DUCT
SLABS
REHEATING FURNACE
CORUS STEEL installation in European Plant
Installed early 2007
Measuring NO,NO2,NH3,O2
Temperature is approx. 450 degrees C
CORUS STEEL MEASUREMENT DATA
CORUS STEEL MEASUREMENT DATA
POSCO STEEL, SLAB REHEATING
FURNACE
= measurement location for Oxygen
d
SLAB
1100°C
Charging zone
Preheating zone
1200 - 1300°C
Heating zone
1100°C
Soaking zone
d : Open-path height from SLAB surface 30 – 40mm
Cross section = 13 metre
MODIFICATIONS MADE FOR REHEATING
FURNACE APPLICATION
Wall
Laser beam
Max 85 degrees C
Max temperature , 40 degrees C
RE060L-T
RC101L+ PS
Furnace duct
1300 degrees C
Max 50 metre cable
50mm diam hole
Instrument air
New modifications:
CF120, max 1000 metre
1.Moved out electronic cards from RE060L, to a separate enclosure that can
be installed at a distance up to 50 metre
LD500
Room temperature ( 15-30 degrees C)
2. Improved laser with 3 mW output compared to old laser with 0.1 mW,
allows better light levels and handling of high dust levels
3.Opsis R&D department has installed a high temp heated measurement
chamber which allows test environments up to 1300 degrees C .This has
resulted in improved spectra handling and evaluations
MONITORING CO AND HYDROCARBONS
CO spectrum ( blue) recorded in
reheating furnace, compared
with factory spectrum( red/blue)
Unknown compounds, most probably hydrocarbons.
Can be presented as unknown compound X,Y,Z etc , if
of any interest for the user.
Absorption is too a large
extension covered by unknown
absorption lines, most probably
hydrocarbons , making it
difficult to reach very low
detection limits for CO ( which
also have weak absorption due
to temperature induced line
widening effects)
R&D is ongoing to overcome
the problems and to reach better
performance for CO
OTHER POSSIBLE APPLICATIONS
Blast furnace off gases ( CO,CO2)
LD converter off gases (CO,CO2,O2)
Coke oven off gas/leaks ( CH4,CO,O2,BTX)
Sinter plant off gas/waste gas ( H2O,HF,HCL)
Technical comparison
Principle
Paths
Signal handling
Comments (+/-)
OPSIS
LD500
Separate TDL
Optical cable
Multiple TDL (4)
Switching TDL
Up to 8 paths
I/O up to
255channels
RS232 with several
ind.protocols
Modem
+Multiple path (max 8)
+Multiple gas ( max 4)
+Also includes logger (IO256)
+Built-in cal.check
NEO
TDL in the emitter
Only 1 path
I/O
RS232
+/-Simple system
- Limit in distance
-TDL on the duct
-Only one path
SIEMENS
Separate TDL
Optical cable
Up to 3 paths
I/O
RS232
+Multiple paths
+Built-in cal.check
BOREAL
Separate TDL
Optical cable
Up to 8 paths
I/O
RS232
+Multiple paths
CONCLUSIONS
Opsis LD500 TDL system features:
• Fast response time (~ 1-10 seconds)
• Semiconductor laser = reliable, long life time
• Multiplexing of up to 8 paths ( = cost effective solutions)
• Multiple gases ( HF,CO, CO2, H2O ,HCL,NH3, CH4…..)
• Up to 4 different gas compounds in the same analyser
• Long fibre cable lengths (< 1 km)
• Low detection limits
• Can operate in high dust environment
• Can operate in high temperature environment
• A minimum of maintenance