working principle:
The zirconium oxide oxygen analyzer converts the electromotive force of the oxygen concentration difference into a standard voltage signal linearly related to the oxygen content of the measured gas by the detection instrument, and inputs it to the input terminal of the digital instrument, and inputs it to the CPU of the instrument through A/D conversion. After calculation, it will be sent all the way to the meter to display the oxygen content, all the way to the meter to display the temperature value, and output the corresponding pulse control signal to control the temperature value, and at the same time convert the oxygen content into a 4-20mA analog signal for transmission and output for other control systems use. The meter is equipped with oxygen content and temperature alarm instructions, and is equipped with an external alarm relay. The instrument uses reliable switching power supply, cold junction compensation uses three-wire Pt100, low-drift operational amplifier, high-resolution A/D conversion, LED high-brightness digital display/liquid crystal display, PID temperature self-tuning control, with 4-20mA, or RS232/485 communication interface.
To
Features:
1. The zirconia oxygen analyzer is composed of a zirconia probe and an oxygen transmitter.
2. The probe is made of anti-corrosion alloy material, zirconia is easy to disassemble and replace, no need to add an air pump, the reference gas is convective by itself, and there is a standard gas interface for background and preset standard gas inspection. It can also be equipped with protective sleeves according to user requirements.
3. The instrument software has complete functions, all panel operations, simple wiring, circuit integration, reliable performance, convenient debugging, and the performance of the meter is at the leading level in the country.
Installation method:
1. Selection of the installation point The flue gas temperature at the installation point should meet the relevant requirements. Generally speaking, the flue gas temperature is low, the detector has a long service life, and the flue gas temperature is high and the service life is short. The detector cannot be installed in a dead corner where the flue gas does not flow, nor can it be installed in a place where the flue gas flows quickly (such as in the expansion cavity of some bypass air ducts). In addition, the flue gas leakage is required to be small, and the detector is easy to install and maintain. For medium and small boilers, it is recommended to install it after the economizer front superheater, because the flue gas of the boiler system flows from the furnace to the steam drum, and passes through the superheater and the economizer. The coal heater and air preheater are discharged from the chimney after recovery treatment by the induced draft fan. If the measuring point is too close to the flue gas furnace outlet, because the temperature is too high and the flow rate is faster, it will cause erosion and corrosion to the stainless steel housing of the detector, shortening the service life; if the measuring point is too far behind, due to air leakage in the flue system, This will cause the oxygen content at the measuring point to be too high, which cannot faithfully reflect the oxygen content of the flue gas in the furnace.
2. The detector fixing flange on the furnace wall is made of steel as a transition frame. The flange of the transition frame can be directly welded to the furnace wall or buried in the furnace wall, but it is required to be airtight and firm. The flange at the other end of the transition frame is for fixing the detector, so it must match the screw hole of the fixing flange of the detector. If you choose 12mm mounting holes, spread four ￠12mm mounting holes on the ￠130mm circle of the transition frame flange, and use 4 M1O×40 screws to fasten it to the fixed flange of the detector. To prevent air leakage, a rubber cardboard sealing ring can be filled between the two flanges. To
3. Installation of the detector The reference gas of the detector is provided by natural convection of the air, and the detector needs to be installed horizontally, with the reference gas and standard gas ports facing downwards accordingly. Rubber cardboard must be filled between the detector mounting flange and the transition frame flange to prevent air from leaking into the flue and affecting measurement accuracy. The end of the detector must be more than 150mm away from the inner wall of the boiler, so that the exposed part of the porous ceramic of the filter faces the flow direction of the flue gas (the direction of the filter can be rotated separately) to prevent the ceramic body from being washed by the gas and prolong the service life. When the detector is pushed into the hot flue, in order to prevent the zirconium tube from bursting, it should be pushed in gradually, generally 10-20 cm/min.
4. There are six wires in total between the sensor and the secondary instrument or transmitter, including zirconia, thermocouple, and heating furnace, all of which can be O.75mm2 plastic insulated wires.
How to choose
The following aspects are mainly considered for selection:
一. Converter
The converter has a panel mount (LZ-2D): The hole size is 75+2mm×150+2mm.
Wall-mounted (LZ-2C): Installation size: 260mm×205mm×90mm.
The display range of the converter is: 0-20.6 percent or 0-10 percent.
output is: 4-20mA.
The upper and lower limits are normally open nodes, and the user can set the alarm point by himself.
二. Detector
1. Insertion depth selection: furnace wall thickness + 300mm (the length of the detector is 400mm, 600mm, 800mm, 1000mm, 1200mm to choose from)
2. Selection of installation point flue gas temperature:
Smoke temperature <700℃, choose JH standard detector
Smoke temperature ≥700℃, select JH high temperature detector
LZ series zirconia has the following main features:
1. The sensor uses Japanese ion plating technology, which greatly improves the service life.
2. The zirconia probe adopts a full 321 stainless steel (1Cr18Ni9Ti) sheath, which has good wear resistance and corrosion resistance.
3. In-line type: No sampling system is required, fast response, and effective reduction of ash blockage in the flue gas.
4. Thermal diffusion reference: No need for a special reference air pump, easy to use and maintain.
5. Double parameter design: overcome the dispersion of domestic zirconia performance, accurate measurement and prolong service life.
6. Working condition online calibration: accurate and reliable, single standard gas online calibration is convenient, working condition points can be calibrated directly, and the measurement is accurate.
7. Thermal inertia protection: easy to install, can be installed thermally, and has strong adaptability to stop and start the furnace.
8. The components are detachable: the components are easy to replace, easy to maintain, and reduce the cost of use.
9. Multi-function display: oxygen content (percent); oxygen potential; temperature, background potential parameter digital display is intuitive and convenient
10, dual range: with 0–10% and 0-% 20.6 dual-range at the same time, the measurement range is wide.
11, dual output: at the same time with switch node output and 4-20mA output.
12. Large load: 750 ohm/4-20mA, which is convenient for remote installation.
13. The background potential is adjustable, and the adjustment range is wide, and the parameters such as component aging can be checked at any time.
14. Full-floating design: common mode input, strong resistance to electric field interference, no special ground wire, easy installation.
15. Product serialization adaptability is strong: it can be applied to various furnace types of gas, oil and coal. Appropriate models can be selected for measuring temperature from room temperature to 1400 degrees.
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