The layout of fixed combustible gas detectors needs to comprehensively consider gas characteristics, site environment, and regulatory requirements. The specific layout requirements are as follows:
1、 Installation location selection
Based on the relationship between wind direction and release source
Priority on the upwind side: The detector should be placed on the upwind side of the minimum frequency wind direction of the combustible gas release source to capture the leaked gas as early as possible.
Downwind side restriction distance: If located on the downwind side, the distance between the detector and the release source should be shortened (such as combustible gas ≤ 5 meters, toxic gas ≤ 1 meter) to ensure timely response.
Coverage radius and spacing
Indoor effective coverage radius: usually 7.5 meters, which means a single detector can cover an area within a radius of 7.5 meters.
Outdoor effective coverage radius: expanded to 15 meters, suitable for outdoor or semi outdoor equipment areas.
Spacing within enclosed factory buildings: Install one detector every 15 meters, and the distance from any release source should not exceed 7.5 meters; The distance between the toxic gas detector and the release source should be ≤ 1 meter.
Strengthen the distribution of points in special areas
Easy to accumulate dead corners: such as trenches, low-lying walls, basements, etc., detectors need to be added. It is recommended to wall mount the basement at a distance of 0.3 meters from the ground.
Steel structure warehouse: Install dual monitoring units near the main beam to expand the monitoring range.
Gas cylinder storage area: Gas is prone to accumulate at the top, and detectors need to be installed in the vertical areas of 50% of the ceiling and 50% of the ground.
Vertical Position Differentiation Processing
Ground release source: Equipped with a shockproof base detector, installed 80 centimeters above the ground, to monitor leaks within a horizontal diameter of 4 meters.
High altitude release source: For example, at the flange interface of the process pipeline, detectors should be installed synchronously at a depth of 80-150 centimeters below the corresponding plane to prevent gas dispersion and leakage.
2、 Installation height specification
Gases heavier than air (such as liquefied petroleum gas)
Install at a height of 0.3-0.6 meters from the floor (or floor), close to the ground to capture sinking gases.
Gases lighter than air (such as natural gas, hydrogen)
The installation height should be 0.5-2 meters higher than the release source, or installed at the top of the protected space (such as 30-60 centimeters from the ceiling) to capture rising gases.
A gas with a density similar to that of air
It can be set in the middle or top of the protected space to ensure comprehensive coverage.
3、 Environmental and Protection Requirements
Avoid harsh environments
Stay away from high temperature (>70 ℃), high humidity, and high dust areas to prevent sensor damage or false alarms.
Avoid installation near steam, oil fumes, and strong magnetic fields (such as maintaining a distance of ≥ 1.2 meters from an 80A three-phase motor) to reduce interference.
protective measures
Explosion proof requirements: Explosion proof detectors should be selected in flammable and explosive places, and electromagnetic shielding measures should be taken (such as double-layer metal shells).
Waterproof and dustproof: Outdoor or humid environments should choose equipment with a protection level of IP65 or above, and install protective covers.
Mechanical damage prevention: Avoid installation in areas where personnel frequently move or are susceptible to impact, and install protective barriers if necessary.
4、 System integration and linkage
Independent Instrument System
The combustible gas detection and alarm system should be set up independently to avoid mixing with other systems and ensure rapid response.
linkage control
When the detector alarms, it is necessary to link the sound and light alarm lights, fans, solenoid valves and other equipment to achieve automatic risk elimination (such as cutting off the gas source and starting ventilation).
5、 Maintenance and Calibration
periodic calibration
According to the manufacturer's guidelines, calibration should be conducted every six months to one year, using standard gases such as isobutane and n-hexane to verify accuracy.
Special gases such as silane and methylamine require the use of specialized calibration gases and adjustment of sensitivity parameters.
routine maintenance
Clean the probe monthly and wipe it with a neutral solvent (pH 6-8) to avoid the use of corrosive substances such as pesticides and alcohol.
Check the connection lines and circuit impedance (stable within the range of 100 ± 25 Ω for a long time) to ensure the normal operation of the equipment.
lifetime management
Gas sensors typically have a lifespan of no more than 5 years and need to be replaced upon expiration; Accumulated usage for 120 hours to generate maintenance alerts and handle them promptly.