The on-line monitoring system for enterprise waste gas treatment needs an installation and operation platform. What are the requirements for its installation location and how to set it? The following is the requirements for the installation position of VOCs processing online monitoring system.
1. The installation position shall be air tight, located downstream of the emission control equipment of fixed pollution sources and upstream of the comparison monitoring section, free from the influence of ambient light and electromagnetic radiation. The vibration amplitude of the flue shall be as small as possible, and the installation position shall avoid the interference of water droplets and water mist in the waste gas as far as possible. If it cannot be avoided, applicable detection probes and instruments shall be selected.
2. A waterproof low-voltage distribution box shall be set in the working area where nmhc-cems is installed, with leakage protector and no less than 2 10A sockets to ensure the power required by Z monitoring equipment.
3. Sampling platforms and sampling holes shall be arranged reasonably.
a) The length of the sampling or monitoring platform shall be ≥ 2m, the width shall be ≥ 2m or not less than the extension of the sampling gun length by 1m, the safety and Q protection fence of more than 1.2m shall be set around, and there shall be firm and qualified safety and Q measures to facilitate daily maintenance and comparison monitoring.
b) The sampling or monitoring platform shall be easy for personnel and monitoring instruments to reach. When the sampling platform is set at a height ≥ 2m from the ground, there shall be an inclined ladder (or Z-shaped ladder and rotary ladder) to the platform, and the width shall be ≥ 0.9m; When the sampling platform is set at a height ≥ 20m from the ground, there shall be a lift to the platform.
c) When nmhc-cems is installed in a rectangular flue, if the height of the flue section is > 4m, it is not suitable to set up a reference method sampling hole at the top of the flue; If the width of the flue section is > 4m, reference method sampling holes shall be set on both sides of the flue, and Multi-layer sampling platforms shall be set.
d) Sampling holes for reference method shall be reserved downstream of nmhc-cems monitoring section, and the location and number of sampling holes shall be determined according to the requirements of GB / T 16157. The inner diameter of the sampling hole of the existing pollution source reference method shall be ≥ 80mm, and the inner diameter of the sampling hole of the new or reconstructed pollution source reference method shall be ≥ 90mm. On the premise of not affecting each other's measurement, the sampling hole of the reference method shall be as close to the nmhc-cems monitoring section as possible. When the flue is a positive pressure flue or there is toxic gas, a sealed sampling hole with gate valve shall be used.
e) If there is no proper sampling hole, the sampling pipe can be inserted directly from the discharge port into 2 times the diameter or 2m depth for sampling. If the sampling hole is located at the negative pressure of the discharge pipe, the sampling pipe and the sampling hole shall be w fully sealed.
4. Preference shall be given to the vertical pipe section and flue negative pressure area to ensure the representativeness of the collected samples. The measurement position shall avoid the flue elbow and the parts with rapid change of section. For new emission sources, the sampling platform shall be designed and constructed synchronously with the exhaust device.
5. In order to facilitate the verification, comparison and monitoring of flow rate reference methods, nmhc-cems should not be installed at the position where the flow rate of exhaust gas in the flue is less than 5m / s.
6. If the exhaust of a fixed pollution source enters the main exhaust pipe of the fixed pollution source after passing through multiple flues or pipes, nmhc-cems shall be installed on the main exhaust pipe as far as possible, but it shall be convenient to verify nmhc-cems by reference method; Nmhc-cems shall not be installed on only one flue or pipe, and the measured value shall be taken as the emission result of the source; However, on each flue or pipe is allowed
7. When the fixed pollution source waste gas purification equipment is equipped with a bypass flue, nmhc-cems or smoke temperature and flow CMS shall be installed in the bypass flue, and its installation, operation, maintenance, data acquisition, recording and uploading shall meet relevant technical requirements.