Installation of zirconia oxygen analyzer probe

A: Selection of installation point:

The flue gas temperature at the installation point of the GKZO zirconia oxygen analyzer probe of Shanghai Guike Instrument Technology should meet the requirement of less than 600 ℃. Generally speaking, low flue gas temperature results in long probe service life, while high flue gas temperature results in short service life. The probe cannot be installed in blind spots where smoke does not flow, nor can it be installed in places where smoke flows quickly (such as expansion chambers in some bypass airways). In addition, it is required that the flue gas leakage be small and the probe installation and maintenance be convenient. For medium and small boilers, it is recommended to install it before the economizer and after the superheater, because the flue gas flow of the boiler system from the furnace to the steam drum, passes through the superheater, economizer, and air preheater, and is recovered and treated by the induced draft fan before being discharged from the chimney. If the measuring point is too close to the outlet of the flue gas furnace, due to high temperature and fast flow rate, it will cause erosion and corrosion to the stainless steel shell of the probe, reducing its service life; If the measuring point is too biased, due to gas leakage in the flue system, the oxygen content value at the measuring point will be too high, which cannot accurately reflect the oxygen content of the flue gas in the furnace.

B: Probe fixing flange on furnace wall:

The transition frame is made of steel in the shape shown in Figure 6. The flange of the transition frame can be directly welded to the outer wall of the furnace wall or buried in the furnace wall, but it is required to be airtight and firm. The flange on the other end of the transition frame is designed to fix the detector, so it must match the screw hole of the fixed flange of the detector. If installing holes with a diameter of 12mm are used, four mounting holes with a diameter of 12mm should be evenly distributed on the transition flange's circle with a diameter of 130mm. Use four M10 × 40 screws to fasten it to the fixed flange of the detector. To prevent air leakage, rubber cardboard sealing rings or metal gaskets can be filled between the two flanges.

C: Installation of probe:

The reference gas for the zirconia oxygen analyzer probe is provided by natural air convection. The probe needs to be installed horizontally, with the reference gas and standard gas interfaces facing downwards. Rubber cardboard or metal gaskets must be filled between the probe installation flange and the transition frame flange to prevent air from leaking into the flue and affecting measurement accuracy.

The probe tip must be at least 150mm away from the inner wall of the boiler, so that the exposed part of the porous ceramic of the filter faces away from the flow direction of the flue gas (the direction of the filter can be rotated separately) to avoid the ceramic body being washed away by gas and extend its service life.

When the probe is pushed into the flue, to prevent the zirconium tube from bursting, it is advisable to gradually push it in sections, generally at a rate of 10-20 centimeters per minute. (See Figure 7)

D: Selection of insertion depth:

The insertion depth of the zirconia oxygen analyzer probe is generally inserted into the center position of the flue or furnace, because the measurement at the center position is more accurate, and the flow direction of the flue gas is more easily detected by the zirconia probe zirconium element at the center position. So the selection of insertion depth is generally half of the flue depth plus the thickness of the furnace wall plus the thickness of the welded short pipe and flange. If you encounter any unclear areas during the selection process, please feel free to call Shanghai Guike Instrument Technology for consultation. We will provide professional guidance to respond to your on-site situation