Pre-blowing burners require a period of pre-blowing before combustion to remove or dilute the remaining gas in the furnace and flue. Due to the inevitable residual gas in the furnace during the burner's operation, there is a risk of explosion if combustion occurs without pre-blowing. It is necessary to remove the remaining gas completely or dilute it to ensure the gas concentration does not exceed the explosion limit. The pre-blowing time is related to the furnace structure and the amount of air blown, and is generally set between 15-60 seconds.
2. For active combustion gas burners, it is advisable to use electric spark ignition for easy active control. High-voltage arc ignition transformers can be used, requiring an output energy of: voltage ≥ 3.5KV, current ≥ 15mA, with a combustion duration typically ranging from 2 to 5 seconds.
3. Monitoring of Combustion Status: The requirement for dynamic monitoring of combustion status necessitates that, upon detection of an extinguishing signal by the flame detector, there must be an immediate response to the combustion unit, which then enters a maintenance state while simultaneously cutting off the gas supply. The flame detector must be able to accurately detect flame signals without being overly sensitive or slow. Over-sensitivity can lead to false actions in case of fluctuations in the combustion status, while being slow results in a delayed response to flame signals, which is detrimental to safe operation. Generally, the requirement is that the response time from the extinguishing of the flame to the flame detector's signal does not exceed 0.2 seconds.
4. In cases where a maintenance gas combustion boiler fails to ignite upon introducing gas, the gas ignites and burns. The combustion process must occur before the gas is introduced, first establishing a combustion temperature field to facilitate ignition. If ignition fails, the flame detector fails to detect a flame signal, and the boiler enters maintenance mode. The time from combustion to entering maintenance mode must be appropriate, neither too short nor too long. Too short, and there's no time to form a stable flame; too long, and when ignition fails, it results in excessive gas entering the furnace. Generally, it is required that within 2-3 seconds of introducing gas, the gas combustion boiler judges the flame signal detected by the flame detector. If it's not ignited, it enters maintenance mode; if it's ignited, it maintains combustion.
5. In the combustion process of the flame-out maintenance gas burner, if an unexpected flame-out occurs, the burner enters a maintenance state. Since the furnace chamber is hot, the gas entering is prone to explosive combustion, therefore, it must enter the maintenance state within an extremely short time to cut off the gas supply. The response time from the occurrence of flame-out to the burner entering the maintenance state should not exceed 1 second.
6. Maintaining the gas pressure within specified limits is crucial for the stable combustion of gas burners, allowing only slight fluctuations within a certain range. The purpose of limiting the pressure variations is to ensure flame stability: preventing flameout, extinguishing, or flashback. At the same time, it controls the burner's output thermal power, ensuring safe and economical operation of the equipment. If the gas pressure exceeds this range, the burner's operation should be adjusted. Burner designs typically use gas pressure switches to sense pressure signals and output switch signals, which are used to control the burner's corresponding operations.
7. Lack of maintenance on air pressure can result in high thermal intensity in gas combustion boilers, which utilize forced-draught combustion methods. In case of a fan failure causing air interruption or insufficient air supply, immediately shut off the gas; otherwise, the furnace may explode or backfire into the fan.
Therefore, while enhancing the quality of wind turbines, the demand for gas control is linked to air pressure. When air pressure is insufficient, the supply of gas should be immediately cut off. Generally, gas pressure switches are used to sense air pressure signals and output switch signals, which are then used to control the corresponding operations of the gas solenoid valves.
