VOCsWorking principle and selection guidance of gas monitoring system

According to national statistical data,Every year in our countryThe emissions of V0Cs are approximately 30 million tons, with industry accounting for 43%, transportation accounting for 28%, domestic sources accounting for 15%, and agricultural sources accounting for 14%. The industrial emission sources are generally chemical industry, oil refining industry, chemical raw material production, pharmaceuticals, coking, synthetic fibers, electronic manufacturing, automobile manufacturing, furniture manufacturing, wood industry, packaging and printing, equipment manufacturing, rubber industry, coating and paint industry, pesticide industry, etc.

VOCs, as one of the important sub sectors in environmental monitoring, have a market space mainly reflected in two aspects: air quality monitoring and pollution source monitoring in key areas; Its function can provide environmental protection departments with monitoring of the current air quality status in the monitoring area, as well as monitoring of enterprise pollution emission data; At the same time, it can also provide evidence for environmental disputes;Below is Jishun An TechnologyTaking JK2000-VOC online monitoring system as an example, briefly introduce the working principle and selection points of VOCs gas monitoring system.

VOCsProduct description of online monitoring system:

JK2000-VOCsThe online monitoring system is mainly used for online monitoring and analysis of various atmospheric emission pollution sources and online monitoring of plant boundary concentrations.

The main principle is that the sampling unit collects the measured gas on site, the preprocessing unit cools, dehumidifies, and filters dust from the gas, and keeps the temperature and humidity of the measured gas constant within a certain range. The gas detection unit detects and analyzes the gas being transported, displays the concentration of the measured gas in real time on the display screen, and transmits the data signal to the outsidePLC or computer terminals can also be transmitted to cloud servers through wireless GPRS or network, and users can read data from the servers to achieve global network monitoring and analysis. The entire process is automated and does not require human intervention.

The JK2000-VOC online monitoring system is suitable for gas detection and analysis in low dust, temperature, and humidity environments. If the dust content of the measured gas is high, an automatic blowback system needs to be selected, otherwise the dust filter needs to be manually maintained and cleaned regularly. The JK2000 gas pretreatment system is equipped with a built-in high-efficiency compressor water-cooled dehumidification system and a 0.5-meter fine dust filtration sampling head (flange installation), with a sampling distance of 40 meters, automatic cooling, automatic drainage, and tar filtration. For the detection and analysis of gases that are easily soluble in water and outdoor icing environments in winter, insulation and electric heating constant temperature control systems should be selected to prevent the sampling pipeline from icing. If you have high requirements for the dryness and cleanliness of the tested gas, please choose the JK3000 series, which includes insulation and electric tracing constant temperature control system, dual effect compressor water-cooled dehumidification system, and can control the stability of the gas at 4 ℃ or 5 ℃

Product features of VOC online monitoring system:

Optional explosion-proof and waterproof design(Standard non explosion proof, IP66 protection, outdoor type), fast, reliable, and stable detection.

The gas analysis unit can be built into the chassis or external.

The standard sampling distance is30-40 meters, optional vacuum pump for remote sampling distance exceeding 70 meters.

The standard pre-treatment temperature isAt 600 ℃, JK2000 can pretreat flue gas at 1300 ℃, and JK3000 can pretreat flue gas at 2000 ℃.

7-inch display screen, capable of integrating various probe parameters and controlling other devices.

Network transmission4-20mA input, RS485 input, 4-20mA output, RS485 communication.

Optional: No display window or2.5-inch display screen, wireless transmission, sound and light alarm, data printing function, touch screen, 16GB large capacity SD memory card to store 20 million pieces of data. Cloud system, HJT212 protocol for environmental protection bureau networking.

VOCsIntroduction to the principle of online monitoring system:

Adjust the sample gas according to the acceptable pressure, temperature, humidity, and flow rate of the analyzerThe dust content and cleanliness level are used to complete its processing function, mainly completing the following tasks:

Sample sampling: Use a vacuum sampling pump or a brushless DC pump to extract the sample gas from the environment such as the flue

Dust filtration: The tested gas passes through a precision dust filter before entering the sampling pipeline. If it is in a dusty environment, an automatic blowback system can be selected

Cooling treatment: Cooling can be achieved through sampling probes and sampling pipelinesGas within 1300 ℃

Optional function: Dual effect compressor water-cooled dehumidification system, which controls the stability of gas within4 ℃ or 5 ℃

Tar treatment: After passing through a tar filter, the sample gas is treated to remove tar and residual dust

Gas water separation: After the sample gas is cooled down through the sampling pipeline, free water appears. The gas water separator separates the gas, water, and residual dust, and automatically drains the water

Secondary filtration: Select according to the humidity level on site and perform secondary water vapor separation

Heat tracing function: This function is optional, providing heating and insulation to prevent water vapor condensation and partial gas dissolution in water. It also prevents the sampling pipeline from freezing in winter

Detection and analysis: Real time detection and display of concentration, andData can be transmitted through signal methods such as 4-20mA/RS485, and can also be transmitted wirelessly or over the network to remote servers, environmental protection bureaus, and monitoring stations

Flow regulation: controlling the intake volume of gas

Gas switching: switching between the measured gas, standard gas, or air

VOCsTechnical parameters of online monitoring system:

System composition: Sampling unit&Sample gas pretreatment unit&Gas analysis unit

Detection parameters:VOC, SO2, NOX, O2, CH4, CO, CO2, NH3, H2S and other gas types can also be detected. Meteorological parameters such as wind speed, direction, rainfall, atmospheric pressure, pipeline pressure, temperature and humidity can also be selected according to customer requirements

Measurement range: Depending on the actual needs of the testing site

Detection principle:PID photoionization, other gas monitoring options include principles such as electrochemistry, infrared, laser, ultraviolet spectroscopy, etc

Sampling temperature:-40 ℃~600 ℃ (standard), optional: -40 ℃~800 ℃, -40 ℃~1300 ℃

Sampling humidity:0~99%RH， Pre treated wet gas

Host working environment:- 40℃~70℃，≤95%RH

Working mode: online continuous work, pump suction sampling(Positive pressure, negative pressure, vacuum environment are all available)

Sampling distance: standard30-40 meters, with a sampling distance of over 70 meters for optional vacuum pumps

Sampling flow rate: adjustable,4 liters/minute (standard), 10 liters/minute, optional

Working voltage:220VAC，50HZ

Output signal:4~20mA、RS485、 Multiple passive contacts, optional: wireless transmission, network transmission

Overall dimensions:800mm * 500mm wide * 340mm thick

Protection type:IP66 outdoor waterproof type, optional explosion-proof type

Display mode: Standard products are displayed without windows, optional2.5-inch or 7-inch touch color screen display

Data storage:100000 pieces of data, optional 16GB large capacity SD memory card to store 20 million pieces of data

Printing method: No printing function, optional wireless Bluetooth printer for printing

Alarm method: Optional type sound and light alarm or external type sound and light alarm