Continuous Emission Monitoring & Process Control
The instruments and analyzers produced by Zetian now are widely used at home and abroad. They are: UV DOAS gas analyzer, laser TDLAS gas analyzer, gas analysis module, forward/backward laser dust monitoring devices, hygroscope for high temperature, continuous emission monitoring system (CEMS), denitration escape ammonia analyzer, sulphur analyzer, trace Cl analyzer system, immersive UV broad spectrum water analyzer, ammonia nitrogen analyzer, colorimetric heavy analyzer, anodic stripping voltammetry heavy metal analyzer etc.
After years of developing, Zetian, as one of the most professional cems analyzer manufacturers, has cooperated with and attracted many worldwide clients of online monitoring and process control, including system integrator, agents, operation and maintenance providers, equipment manufacturers, thermal power plants, sewage treatment plants, chemical plants and the like.
Working Principle of CEMS System (Particulate Matter)
Features of the particle measurement subsystem:
1. Direct measurement without sampling system;
2. The probe does not touch the smoke;
3. Because standard materials are difficult to obtain, the factory usually calibrates with filters;
4. Dust and water vapor have a greater impact and are not suitable for measurement after wet purification facilities unless the flue gas is reheated to a temperature above the dew point of water
5. The back blowing air curtain needs 24 hours of operation (also when the furnace is stopped);
6. Changes in particulate composition and particle size affect the calibration of such analyzers;
Particulate matter online performance requirements:
Zero drift: ≤ ± 2% F.S.;
Span drift: ≤ ± 2% F.S.;
Correlation coefficient: ≥0.85 (when the upper limit of the measurement range ≤50mg / m³, ≥0.75)
Working Principle of CEMS System (Gaseous Pollutants)
Classification of online monitoring methods for gaseous pollutants:
1. Extractive continuous monitoring (dilute sampling method, direct sampling method)
a. Dilute sampling method: collect flue gas and remove dust, and then use clean zero gas to dilute the dedusted flue gas according to a certain dilution ratio to reduce the concentration of gaseous pollutants, and introduce the diluted flue gas into the analysis unit for concentration analysis
b. Direct extraction and sampling method (heating pipeline method): Insulate the dedusted flue gas through the heating pipe to keep the flue gas without dew condensation, send it to the drying device for dehumidification, and then send it to the analysis unit for concentration analysis.
Features of dilution extraction system:
1. UV fluorescence measurement SO2, chemiluminescence measurement NOx;
2. Multiple analysis unit combinations are required;
3. The oxygen content needs to be equipped with a separate sampling system or a direct measurement method;
4. The measurement data needs to be converted into the dry flue gas value in the standard state;
5. The sample gas transmission does not use heating pipeline;
6. The air used for probe dilution needs to be strictly controlled;
7. Probe dilution ratio needs to be calibrated at any time;
Features of the direct extraction system:
1. Infrared / ultraviolet light absorption measurement and analysis unit;
2. One analysis unit can measure SO2, NOx, CO2, CO at the same time;
3. The oxygen measurement (O2) unit and infrared unit can be placed in the same analyzer together;
4. The measured data is the dry flue gas value in the standard state, the data is intuitive;
5. Sample gas transmission adopts heating pipeline (above 120 ℃)
6. The pretreatment system is complex;
7. Requires good sealing;
2. On-site continuous monitoring
What we can offer are high cost-effective intellectual monitoring instrumentation and analysis equipment, analysis module /component, CEMS program sets, complete set of water quality analysis program and other similar products. OEM and ODM are acceptable for us, and we can also provide operation, maintenance and other services.
Continuous Emission Monitoring System (CEMS) consists of particulate matter monitoring subsystem, gaseous pollutants monitoring subsystem , flue gas parameters monitoring subsystem, system control and data acquisition and processing subsystem. It can monitor gases such as SO2, NOx, O2, dust, temperature, pressure, flow rate, humidity, etc. It can also be extended for a specific occasion to monitor HCl, HF, CO, CO2, NH3, H2S, Cl2, VOC and other parameters. The measured gas passes through sampling probe for dedusting, heating tube for sampling, then goes into the gas analysis module (violet differential optical absorption spectroscopy (DOAS) for analysis measurements. It effectively solves the technical problems of dust and moisture interference on measurement, particularly in the case of low concentration measurements with an unparalleled advantage.
It applies to the emission monitoring and process analysis of coal-fired power plant, garbage power plant, cement, glass, lime factory, ceramics factory, sinter, coke oven, the process of desulfurization and denitration technology.