What Is a Gas Detection System in Fire Safety?

What Is a Gas Detection System in Fire Safety?

A fire and gas detection system is a crucial component of ensuring safety within various industrial environments. Its primary function is to monitor and identify abnormal conditions, such as fires or the release of toxic or combustible gases within a facility. By providing early warnings and implementing mitigation measures, this system plays a vital role in preventing incidents from escalating, thereby safeguarding both the environment and the ongoing processes.

Key Components of an Effective Fire and Gas System

A comprehensive fire and gas (F&G) solution integrates various elements to create a coherent and well-designed safety apparatus. This includes an assortment of fire and gas detection devices, both analog and conventional addressable fire panels, clean agents or inert gas fire suppression mechanisms, and a SIL 3 certified fire and gas logic solver. Integration fosters the creation of a unified platform equipped with common tools, a shared operating interface, and networking capabilities, ultimately resulting in a synergy of independent systems.

Varieties of Detectors in Fire and Gas Systems

Gas Detectors

Gas detectors are generally classified into two categories:

Flammable Gas Detectors:

These detectors utilize the Lower Flame Limit (LFL) and Upper Flame Limit (UFL) thresholds to gauge the volume percentage of flammable gases in the air.

Toxic Gas Detectors:

Employing the Threshold Limit Value (TLV), toxic gas detectors determine the concentration of harmful gases in parts per million (ppm).

Flammable Gas Detectors:

Within the realm of flammable gas detection, three types of gas detectors are prominent:

Catalytic Gas Detectors:

Operating on the principle of heat production through oxidation, catalytic gas detectors determine gas concentration. It’s important to note that these detectors may under-read when oxygen levels are low in gas-rich environments.

Infrared Gas Detectors:

Infrared gas detectors exploit the characteristic of hydrocarbons and gases to absorb infrared radiation at specific wavelengths. The ratio of measurements taken at different wavelengths provides the concentration of gas without signal intensity variations.

Open Path (Line-of-Sight) Gas Detectors:

Open-path detectors sense gases over long distances by utilizing their property of infrared radiation absorption. This is achieved by combining the property with high-energy sources.

Toxic Gas Detectors:

Toxic gas detectors encompass two primary categories:

  1. Detectors for immediately hazardous gases (e.g., H2S, CO, HF, HCl, Cl2).
  2. Detectors for gases that pose long-term health risks (e.g., Vinyl Chloride, Benzene, Toluene).

H2S Detectors:

Two major types of H2S detection devices are used:

Electro-Chemical Cell Type:

This type employs an electrochemical reaction cell designed specifically for H2S detection. An organic electrolyte reacts with H2S to generate an electric current proportional to the gas concentration.

Semi-Conductor (MOS) Type:

Semi-conductor detectors rely on the adsorption of H2S molecules onto the surface of solid-state crystals, altering electrical resistance within the circuit.

Fire Detectors:

Fire detectors fall into three main categories:

  1. Smoke Detectors
  2. Heat Detectors
  3. Flame Detectors

In Conclusion:

Gas detection systems in fire safety are instrumental in maintaining safe industrial environments. By incorporating various detectors and logic controllers, these systems offer early warnings and effective mitigation measures to prevent accidents, protect processes, and preserve the well-being of both the environment and personnel. As technology continues to advance, these systems play an indispensable role in ensuring operational safety across various industries.

This post was written by Justin Tidd, Director at Becker Mining Communications! For over 15 years, Becker Communications has been the industry’s leader in underground radio electrical mining communication systems. As they expanded into surface mining, railroads, and tunneling they added wireless communication systems, handheld radios, tagging, and tracking systems, as well as gas monitoring.

Antoine Mitchell