- Advanced fire detection system
- Specially designed for fire detection on coal mills and silos
- Continuous self-checking of measurement integrity
- Tailored to each application/plant
- Standard analog and discreet contact outputs
- Protect expensive mill equipment and prevent downtime
- Robust , low maintenance system
- High level of reading confidence
- Tailored to each application
- Easy connection to plant control equipment
This unique detection system, is specifically designed to detect rapid build-up of carbon monoxide inside pulverizingcoal mills. It continuously monitors the atmosphere inside the mill, and responds very quickly to any significant increase in the levels of CO, created by the onset of a mill fire. This provides the operator with advance warning to enable preventative action to be taken before damage to the plant, or injury to personnel occurs.
Why Carbon Monoxide (CO) ?
The close monitoring of CO, as opposed to temperature sensing, provides much earlier detection of combustion and subsequent prevention of a mill fire. The CO system will detect changes significantly faster - in time to prevent damage.
How it works?
The Mill Fire Detector extracts sample gases from the mill (often the mill outlet) and continuously monitors the levels of carbon monoxide (CO). Dual sensors continuously monitor CO, with self-checking and autocalibration to maintain integrity.
Alarm threshold levels can be set to best suit the plant operating conditions. These settings can also compensate for externally introduced CO, where mills are using recycled combustion air for coal feed heating.
Optional Oxygen Measurement
Measurement of oxygen is an option in the single stream measurement instrument. Oxygen-limited silos will benefit from the additional measurement as an additional fire prevention precaution. Similarly, plants using re-cycled flue gas can continuously monitor oxygen levels.
- CO Ranges (selectable):
- 0-100 up to 4 000 ppm in 50 ppm steps or
- 0-100 up to 5 000 mg/nm3 in steps of 50 mg/nm3
- Resolution: 1 ppm / 1 mg/nm3
- Linearity: < 2 % of range
- Zero drift: < 2 % of range per month
- Span drift: < 2 % of range per month
- Optional O2 Ranges (selectable): 0 - 5 % to 0 - 25 %
- Resolution: 0.1 Vol %
- Linearity: < 0.2 Vol %
- Zero drift: < 0.2 Vol % per month
- Span drift: < 0.2 Vol % per month
- Response time: < 30 secs. to T90 (excluding sample line)
- Calibration method:
- 2-point calibration span and zero
- Microprocessor controlled
- Type: LCD (Supertwist)+ LED backlight
- Size: 60 x 16 mm / 2.4 x 0.6 in
- Parameters: 4 x 20 character dot matrix, 8 access keys
- Type: 2 LEDs on door panel
- Use: ‘Power On’ and ‘System OK’
- Analog output: Single, isolated current loop for each CO level & O2 if fitted, 0, 2 or 4 mA to 10 or 20 mA
- Relay outputs: 2 x Level Alarms; System OK; Calibration/Maintenance
- Relay rating: Isolated changeover S.P. 1 A @ 240 V a.c., or 5 A @240 Vd.c. resistive
- Auto cal relay contacts: Zero, Span check/calibration
- Auto cal initiation contacts: For use with external contact closure
- System enclosure: Painted steel, sealed IP65 / NEMA 4
- Operating (ambient) temperature:
- 0 to +45 °C / 32 to 113 °F standard
- to -20 °C / -4 °F with optional case heater
- to + 50 °C / 122 °F with optional air conditioner
- EMC: Conforms to EN-50 081 & EN-50 082
- Electrical safety: Conforms to EN-61010-2
- Power supply: 83 V a.c. to 132 V a.c. or 165 to 264 V, 50 - 60 Hz
- Power consumption: 300 W
Gas and Air requirements
- Instrument air (zero calibration): 2 bar / 30 psi clean and dry, 5 l/min / 0.2 cfm
- Instrument air (cooling): 5 - 10 bar /70 - 150 psi clean and dry, 300 l/min / 10.5 cfm
- Calibration gas (recommended): 2 bar / 30 psi, 20 litres (0.7 cu.ft.) per calibration approx.
- Calibration gas type: CO in N2; Air for O2
- (H x W x D): 600 x 600 x 350 mm / 24 x 24 x 14 in
- Weight: 53 kg / 117 lb
- Twin Stream System Sample Probes and Lines
- Heating/Cooling Oxygen Measurement (Single stream only)
- Multi-point Switching Unit