Gas burner working process has four stages: preparation stage, pre-purge stage, ignition stage and normal combustion stage.
Take the proportional gas burner as an example.
Start the internal sequence self-test, preparation phase: after the program controller is powered on. At the same time, the servo motor drives the damper to the closed state. After the sequential self-check is completed, it is in the standby state. When the limit switches such as the thermostat, excessively high and low gas pressure switches, and steam boiler steam pressure switches allow, the programmer starts to start and enters the pre-set state. Purge phase. If the solenoid valve group is equipped with a leakage detection system, the system will first perform valve leakage detection when the above-mentioned limit switch permits, and then enter the pre-purge stage after passing the detection. At the same time, the fan motor starts, and the pre-purge stage: the servo motor drives the air door to the high-fire opening state. Pre-purging is performed by blowing in air. Depending on the program controller, about 20-40 seconds after purging, the servo motor drives the damper to the ignition opening state, ready for ignition. Throughout the pre-purge stage, the air pressure switch measures the air pressure. Only when the air pressure is maintained at a sufficiently high level, can the pre-purge process continue. Ignition transformer cuts in, ignition phase: after the servo motor drives the air door to the ignition opening state. And output high voltage to the ignition electrode to generate ignition spark. After about 3 seconds, the programmer sends power to the safety solenoid valve and the proportional solenoid valve. After the valve is opened, the gas reaches the combustion head and mixes with the air provided by the fan. Was ignited. Within 2 seconds after the valve is opened, the ionization electrode should detect the presence of flame. Only in this way, the programmer will continue the following sequence, otherwise, the programmer will lock and disconnect the solenoid valve to stop the gas supply and alarm at the same time.
The servo motor drives the air door to the high-fire opening state, the normal combustion stage: the ignition is normal and stable combustion after a few seconds. At the same time, the servo motor of the proportional gas regulating valve is cut in, and the gas pressure after the gas valve is adjusted according to the air pressure and the back pressure of the furnace to adjust the gas volume to achieve the purpose of stable and efficient combustion. Afterwards, the burner is switched on and off according to each limit. It is required to automatically realize the large-scale fire conversion and shutdown. In addition, during the entire combustion process, the ionization electrode and the air pressure switch monitor the burner.
