1Zirconia Explosion proof Oxygen AnalyzerSite selection criteria: Ensure measurement accuracy and equipment lifespan
temperature control
The flue gas temperature at the installation point should be controlled between 100-600 ℃ to avoid high temperature accelerated oxidation corrosion or low temperature induced sulfuric acid condensation corrosion of zirconium pipes.
Recommended location: It is recommended to install small and medium-sized boilers before the economizer and after the superheater, where the flue gas flow is good and the temperature is moderate.
Airflow conditions
Avoid dead corners of smoke, vortex areas (such as bypass airway expansion chambers), and constrictions to prevent slow response or oxygen fluctuations.
There should be no manholes or obvious leaks within 5 meters upstream of the installation point to avoid external air infiltration and high measurement values.
environmental safety
Stay away from vibration sources (such as fans) and flammable gas areas to prevent probe damage or measurement interference.
Ensure that the installation location is convenient for daily maintenance (such as sampler insertion and extraction, calibration operations).
2、 Installation steps: Details determine stability
Installation of furnace wall fixed flange
Use steel to make a transition frame, with one end welded or embedded in the furnace wall, and the other end flange matched with the detector fixing flange (such as evenly distributed 4 M10 × 40 screw holes).
Rubber cardboard sealing rings are filled between the flanges to prevent air leakage from affecting measurement accuracy.
Detector installation
Horizontal installation: The detector needs to be inserted horizontally into the flue, with the reference and standard gas ports facing downwards to prevent dust blockage.
Push in method: When inserting into the hot flue, use segmented push in method (10-20 cm/min) to avoid the zirconium tube bursting due to sudden temperature differences.
Depth requirement: The detector end should be at least 150mm away from the inner wall of the boiler, and the porous ceramic filter should face away from the flue gas flow direction to reduce erosion and wear.
Installation of transmitter
Keep away from high temperature, humidity, and corrosive gas environments. The size of the instrument panel opening should match the transmitter, and lock the fixing clip after installation.
3、 Wiring specification: Ensure signal transmission stability
Wire selection
Oxygen electrode signal line: 1.0-1.5mm ² shielded wire is used to reduce electromagnetic interference.
Thermocouple wiring: Use K-scale compensating wires to ensure temperature measurement accuracy.
Heater wire: Use ordinary wires with a rating of ≥ 2A to avoid safety hazards caused by overheating.
Wiring steps
Oxygen potential wiring: Instrument oxygen potential+probe oxygen potential+, oxygen potential - probe oxygen potential -, laid in conduit A.
Thermocouple wiring: instrument thermocouple+probe thermocouple+, thermocouple - probe thermocouple -, laid in the same tube as the oxygen potential line.
Heating wiring: Two heating terminals are not divided into positive and negative poles. Use a 2.0mm ² wire to connect the probe and the instrument, and lay it in conduit B (placed separately from the signal wire).
Precautions
K-division compensation wire: The positive and negative poles cannot be reversed, otherwise it will cause abnormal temperature display.
Sealing of junction box: Ensure that the junction box is not mechanically loose to prevent dust from entering and affecting signal transmission.
4、 Debugging and acceptance: Ensure the normal operation of the equipment
Preheating treatment
Preheat the zirconia probe for 1 hour after power on to reach a stable operating temperature (usually 700 ℃).
calibration operation
Use standard gases (such as 5% O ₂+N ₂ equilibrium gas) for span calibration to ensure measurement error ≤ level 2 (or even achieve level 1 accuracy).
Calibration cycle: Instruments connected to the self-control system should be calibrated every 1-2 months, while instruments not connected to the system should be calibrated every 3 months.
performance testing
Response time: The instrument has a stable reading time of ≤ 7 seconds from contact with the measured gas to output (shorter for fast response scenarios).
Insulation resistance: measured with a 500V megohmmeter, the insulation resistance of the thermocouple to the probe housing is>20M Ω, and the insulation resistance of the heating furnace to the probe housing is>5M Ω.
5、 Safety and Maintenance: Extending Equipment Lifespan
safety protection
Wear a safety helmet, protective goggles, and gloves during installation to avoid burns or mechanical damage from high temperature smoke.
It is strictly prohibited to disassemble equipment or touch sensors in explosive gas environments.
Zirconia Explosion proof Oxygen Analyzerroutine maintenance
Filter cleaning: Regularly replace the white filter to prevent dust blockage from affecting gas penetration.
Sensor inspection: Keep the sensor surface clean to avoid oil and dust affecting measurement accuracy.
Pipeline inspection: Regularly check whether the pipeline is blocked, and promptly clean or replace interface components.
Shutdown and startup
When shutting down the furnace: Wait for the furnace to shut down before turning off the instrument. If the shutdown time is ≤ 1 month and does not affect maintenance, the instrument can be left on.
Before starting the furnace: Turn on the instrument first and then ignite to avoid sudden cooling and heating of the zirconia tube, which may cause fracture.