Laser gas analysis
Fields of application
Gas analysers for ship scrubbers measure the concentration of pollutant gases in ship exhaust fumes.
Features
The laser gas analyser for EGCS (ZQS) continuously monitors the SO2 and CO2 concentrations contained in the gases emitted by a marine engine and subsequently cleaned by a SOx scrubber. The ZQS complies with Scheme B of Resolution MEPC 259(68), the 2015 Guidelines for Exhaust Gas Cleaning Systems, adopted by the Marine Environment Protection Committee (MEPC), which is a branch of the International Maritime Organization (IMO).
| Components and ranges | SO₂: 0 to 300 ppm CO₂ : 0 to 10 %vol | ||||||||||||||||||||||||||||||||||
| Principle | TDL (Tunable Diode Laser) for SO2 QCL (Quantum Cascade Laser) method for CO2 | ||||||||||||||||||||||||||||||||||
| Measurement method | Extractive method | ||||||||||||||||||||||||||||||||||
| Application | Exhaust fumes from SOx scrubber (dedicated) for ship engines | ||||||||||||||||||||||||||||||||||
| Light source | Semiconductor laser | ||||||||||||||||||||||||||||||||||
| Laser class | CLASS 1 (laser devices can be Class 1 or Class 3B) | ||||||||||||||||||||||||||||||||||
| Dimensions (W×H×D) mm | Detector: 330 (W) × 880 (H) × 255 (D) mm Extractor: 400 (W) × 300 (H) × 323 (D) mm *Depth varies according to duct diameter Interface: 500 (W) × 400 (H) × 166 (D) mm | ||||||||||||||||||||||||||||||||||
| Weight (excluding cables) | Detector: 30 kg Extractor: 18 kg Interface: 20 kg | ||||||||||||||||||||||||||||||||||
| Housing | Indoor use, IP44 (fully enclosed and splashproof) Extractor fan: IPX4 | ||||||||||||||||||||||||||||||||||
| Materials | Detector: Stainless steel Extractor: Stainless steel Interface: Stainless steel | ||||||||||||||||||||||||||||||||||
| Materials of parts in contact with gas | SUS316L, CaF2, FKM, Silicone, PTFE, Glass, PVDF | ||||||||||||||||||||||||||||||||||
| Power supply | 100-240 Vac, 50/60 Hz | ||||||||||||||||||||||||||||||||||
| Power consumption | Max. rated power 1000 VA | ||||||||||||||||||||||||||||||||||
| Displays | LED indicators | ||||||||||||||||||||||||||||||||||
| Information displayed | Heating, measurement, maintenance request, standby, fault | ||||||||||||||||||||||||||||||||||
| Communication functions | Ethernet / Protocol: Modbus TCP | ||||||||||||||||||||||||||||||||||
| Length of cables | Between receiver and transmitter: 1 m Between detector and interface: ≤ 15 m Between extractor and interface: ≤ 20 m | ||||||||||||||||||||||||||||||||||
| Analog outputs (AO) | 4 to 20 mAcc, 3 points Isolation of ground line and internal circuit. No isolation between signals. Load resistance: ≤ 300 Ω Output signals: SO₂ content, CO₂ content, SO₂/CO₂ ratio. The output signal is forced to 0% during maintenance operations and when the purifier is shut down. | ||||||||||||||||||||||||||||||||||
| Analog inputs (AI) | 4 to 20 mAcc, 1 point Isolation of ground line and internal circuit No isolation between signals Input signals: exhaust gas temperature | ||||||||||||||||||||||||||||||||||
| Digital outputs (DO) | SPST-NO relay contacts, 4-pin Capacity: 30 Vdc, 1 A (resistive load) Internal circuit isolation. Contacts not isolated from each other (shared COM) Output signals: maintenance, heating, sampling stopped, maintenance request, fault analyser (extractor fault, detector fault), power failure | ||||||||||||||||||||||||||||||||||
| Digital inputs (DI) | Voltage inputs, 4 points Contacts ON if input between 18 and 25 V Internal circuit isolation Contacts not isolated from each other (shared COM) Input signals: maintenance, scrubber on/off | ||||||||||||||||||||||||||||||||||
| Performance | |||||||||||||||||||||||||||||||||||
| Accuracy | ≤ ± 2.0% of measurement or ≤ ± 0.3% PE, whichever is greater | ||||||||||||||||||||||||||||||||||
| Detection limit | 2.5 times the standard deviation of 10 repetitive responses: ≤ ± 1.0% PE | ||||||||||||||||||||||||||||||||||
| Noise | ≤ 2.0% PE peak-to-peak | ||||||||||||||||||||||||||||||||||
| Zero drift | ≤ ± 2.0% PE for 6 months | ||||||||||||||||||||||||||||||||||
| Scale drift | ≤ ± 2.0% PE for 6 months | ||||||||||||||||||||||||||||||||||
| Response time (t90) | ≤ 180 s | ||||||||||||||||||||||||||||||||||
| Heating time | ≤ 120 min | ||||||||||||||||||||||||||||||||||
| Interference with other components | With the following component contents in a nitrogen base (N₂): ≤ ± 2.0% PE (1) 500 ppm NO (2) 200 ppm NO₂ (3) 2000 ppm CO (4) 10 ppm NH₃ (5) 10 ppm CH₄ (6) H₂O saturated at 60°C | ||||||||||||||||||||||||||||||||||
Laser gas analyser - ZQS - for marine applications
Reference : ZQS
