How to Safely Control Gas Burners

     We has abundant natural gas and coal-derived gas resources, and these are considered clean energy sources, thus offering significant social and economic benefits. Gas burners align with my country's industrial policies and have excellent market prospects and great potential for development. However, in the design and development of gas burners, the inherent characteristics of gas-flammability, explosiveness, and toxicity-pose major safety control challenges. This article outlines the safety control requirements for gas burners: Based on the combustion characteristics of gas in the combustion chamber, the key safety control requirements include pre-purge, automatic ignition, combustion monitoring, protection against ignition failure, protection against flameout, protection against high/low gas pressure, protection against insufficient air pressure, power outage protection, and measures to prevent gas leaks.

1. Pre-purge Before ignition, a pre-purge cycle is necessary to purge or dilute any residual gas in the combustion chamber and flue. Since residual gas is unavoidable in the combustion chamber during operation, failure to purge before ignition poses an explosion risk. The residual gas must be purged or diluted to ensure the gas concentration remains below the explosive limit. The pre-purge time depends on the combustion chamber structure and airflow rate, generally set at 15-60 seconds.

2. Automatic Ignition Gas burners should use electric spark ignition for easy automation. A high-voltage ignition transformer can be used to generate an electric arc, requiring an output energy of: voltage ≥ 3.5 kV, current ≥ 15 mA, and ignition time of 2-5 seconds.

3. Combustion Monitoring The combustion process must be continuously monitored. If the flame sensor detects a flameout, the burner must react immediately, shutting off the gas supply and entering a safety mode. The flame sensor must be able to accurately detect the flame signal; Boiler Gas Burners should not be overly sensitive or insensitive. Sensitivity can lead to false alarms due to combustion fluctuations, while insensitivity results in delayed reaction, compromising safety. The response time from flameout to the flame sensor signal should not exceed 0.2 seconds.