Laser Analyzers for NH3 Safety Monitoring and Leak Detection

Transcription

1 Laser Analyzers for NH3 Safety Monitoring and Leak Detection

2 Boreal s Worldwide Clients

3 Over 450 systems in 42 Countries Holland Belgium France Germany Italy England Scotland Norway Iceland Canada United States Trinidad & Tobago Mexico Poland Russia Ukraine Dubai Abu Dhabi Bahrain South Africa Mozambique Australia New Zealand Thailand Korea

4 Boreal Products for NH3 Safety Monitoring GasFinder2 (GF) Portable single-channel, open path/ambient monitor GasFinderMC (MC) Fibre-coupled, multiple-channel (up to 8) monitor for open path, stack, or process monitoring shown with long open path head. GasFinderFC (FC) Portable single-channel, fibrecoupled stack monitor Short Open Path Head Transceiver Unit of Cross Duct Probe

5 Why Laser Gas Detection? Specific to one gas no interferences Fast response times (< 1 second) Self Calibrating & no consumables Wide dynamic range (4 orders) low and high concentration measurements possible Robust, reliable technology Can be used with fibre optics Multiplexing reduces cost per measurement Lower maintenance & operating costs

6 Why GasFinder is better than electrochemical sensors? Self calibrating / Auto line centring Not affected by humidity, dust, heat, cold or rapid changes in temperature No memory effects Can t be poisoned by exposure to ammonia Better coverage No consumables Much faster response time Very low associated O&M costs

7 Why GasFinder is better than Open Path IR/UV? Very high resolution means GasFinder more selective Laser diode picks out an individual gas absorption line IR and UV measure many lines over wide wavelength range Therefore GasFinder does not suffer from the interferences that affect open path IR and UV H2O and CO2 (which cause interference in IR detectors) Hydrocarbons in oil & gas related activities (UV & IR) Intense Laser light concentrated at specific wavelength Enables longer range - to 300 m Penetrates fog and steam better Fast response ensures rapid response to gas releases

8 Leak Detection around an NH3 Synthesis Unit GasFinderMC paths provide complete perimeter coverage Wind Direction 1 Retro- Reflector Note that leak 1 creates a cloud that is not detected by any point sensors Leak 2 is detected by 1 or 2 point sensors Point sensor Source of leak GasFinder heads 2

9 Leak Detection in a Compressor Room Lasers are not damaged by the typically high NH3 background levels found in a compressor room so they provide an ideal solution for safety monitoring in this area Source of leak GasFinder heads Retro- Reflector

10 Leak Detection at a Loading Terminal Lasers provide an unbroken line of detection for ship, rail & truck terminals and can monitor in places other sensors cannot. GasFinder head

11 How Laser Gas Detection Works? - Gasses have a unique fingerprint

12 Gasses That Lasers can See Absorb Energy in the Near Infrared Invisible Infrared band Sun or White light Prism Absorption lines Invisible Ultraviolet band Spectral lines Measurement is made in the Near Infrared (N.I.R.) region, less affected by scattering than Visible wavelengths.

13 Principles of TDLAS Tunable Diode Laser Absorption Spectroscopy Absorption Cross-Section Result of Wavelength Scan Over Absorption Peak Harmonic Distortion Through Absorption Laser Scan λ λ I i T i Distributed Feedback Tunable Laser Diode λ o (I,T) The almost monochromatic nature of the laser emission enables TDLAS to isolate individual gas absorption lines. Wavelength Modulation Spectroscopy (WMS) techniques are used to maximize sensitivity. By modifying the diode injection current, the laser wavelength can be scanned across the gas absorption line, resulting in a harmonic distortion signal whose size is dependant on the amount of gas present.

14 GasFinder Schematic & Data Validation Sighting scope Aiming Laser Laser Diode Control Electronics Calibration Reference Cell Detector Detector Signal Processing & Display The lasers Remote Retro-reflector The gas measuring laser light emitted by the Laser Diode is invisible - in the near infrared (between 1100 & nm). Computer The aiming laser used to aid alignment emits a highly visible red light Reference cell contains stable sample of target gas, known concentration. Laser beam redirected through ref cell for 0.25 s every 10 s Current reference cell spectrum checked against stored standard every minute No need for in-path validations with bottled gases and calibration tubes. All GasFinders calibrated against NIST traceable permeation tubes.

15 GasFinderMC Schematic Note How Multiplexer Supports Multiple Paths

16 Typical GasFinderMC Installation. Rack Mounted, Modular and Compact Double-hinged enclosure allows easy access to front and rear of typical rack mounted installation

17 Alarms Gasview MC Software for Easy Assessment of Key Operating Parameters Main Display Status Codes Averaging Instrument Display Light Level Info Log File Information Communication Port

18 Field Components Include Transceiver Heads and Reflectors

19 Some Gas Sensitivities

20 Thanks for your attention! Any Questions? Contact following for more information : John Selby jselby@boreal-laser.com Cell: +1 (403) Neil Campbell ncampbell@boreal-laser.com Cell: +1 (403) photo credit: Dr. Lowry Harper