Overview
SK-7500-LEL-JY LEL on-line monitoring system is an on-line monitoring system for continuous monitoring of LEL (lower explosive limit) content of organic matter in pipelines. The system integrates gas sampling, preprocessing, detection and data management. It has a simple structure, wide dynamic range and strong real-time performance. It can realize on-site unattended and can communicate with the enterprise DCS system.
Features
1. Pre-processing, High Accuracy, Small Overall Size, Easy Installation.
2. Professional gas pretreatment for humid, tar, dust and other harsh environments.
3. Using the original high-performance Sensor, long life, good anti-interference performance, accurate and stable monitoring data.
4. Equipped with an infrared remote control, full-function operation can be achieved without opening the lid.
Standard 4-20mA, RS485 and a set of relay output signals, easy to access industrial control systems such as PLC, DCS or stand-alone control.
6. Optional wireless modules such as DTU and LORA can be used to achieve real-time data upload.
7. Optional 7-inch industrial touch screen, intuitive and clear display of real-time concentration and Linear dispersion map.
Principle
The system adopts active sampling method. After the pipeline gas is extracted by the sampling pump, it is pretreated by precise filtrating, cooling and dehumidification, flow control, etc., to obtain clean, drying and constant sample gas, and then sent to the LEL concentration detector. The detector is based on the principle of infrared NDIR (non-spectral infrared), using the absorption characteristics of different gas molecules to specific wavelengths of infrared light, according to Lambert-Beer's law, the gas components are identified and their LEL concentration is determined by measurement of Absorption intensity.
Applications
Generally used for RTO front-end pipeline monitoring to prevent explosion hazards due to high concentration
Standards
GB3836.1-2010、GB3836.2-2010、GB 3836.15-2000、GBT50493-2019、GB12358-2006、GBZ 2.1-2007、GB 4208-2008、GB 16297－1996、GB/T 16157-1996、GB/T 5468-1991、HJ/T 397-2007、HJ/T 76-2017、HG/T 20507-2014
Steps
1. Determine and install the sampling Probe according to the selection point requirements (e.g. avoid elbows, valves, select vertical pipe sections, etc.).
2. Connect the system power supply (AC220V) and signal output cable (such as 4-20mA, RS485).
3. If the Back flushing function is optional, connect the clean instrument air source (pressure 0.4~ 0.7MPa).
4. The system is powered on, the sampling pump is started, and the sample gas enters the detector after pretreatment.
5. View the real-time concentration through the display screen or infrared remote control, and perform operations such as parameter setting and calibration.
6. The system data can be connected to the industrial control system through the output signal, or uploaded to the server through the optional wireless module.
Notice
• Applicable pipeline working conditions are: temperature ≤ 80 ° C, no or trace dust and water vapor, micro negative pressure, normal pressure or positive pressure, no explosion-proof requirements. If the working conditions exceed, non-standard design is required.
• Installation of sampling points should prioritize the vertical pipe section and the negative pressure area of the flue to ensure sample representativeness.
• The measurement position should avoid the flue elbow and the rapidly changing part of the section. Please refer to the materials for specific distance requirements.
• The system power supply is AC220V, please pay attention to safety when wiring.
• It is recommended to use Shielding cable for signal transmission cable. For long-distance transmission, the wire diameter should be thickened and the Shielding layer grounded.
• If the Back flushing function is selected, the air source needs to be clean, oil-free and water-free instrument wind.
Equipment requires vibration, and the installation environment should meet ≤ 100 Hz (0.3m/s).
• It can be operated by infrared remote control during maintenance to avoid unnecessary opening of the lid.
• Sensors have a lifespan of 2 to 6 years, depending on the usage, and require regular maintenance and calibrating.
