Flameout protection solenoid valves are divided into two series
At present, the extinguishing protection solenoid valve technology is mainly divided into two series:
One is thermocouple plus solenoid valve series. The characteristic of this technology is that the opening of solenoid valve is driven by knob, and the holding of the opening state is accomplished by thermoelectric potential generated by thermocouple.
When the flame is extinguished, the thermocouple loses its thermoelectric potential, the solenoid valve releases synchronously, and the gas path is cut off to complete the extinguishing protection. The disadvantage of this technology is that thermocouples are easy to age. Some cookers have been used for a long time, the thermocouples have aged, and the thermoelectric potential generated is not enough to maintain the suction of solenoid valves, so the fire is extinguished.
Users usually talk about old fire, basically this is the case. Thermocouple technology is low cost, mostly used for open stoves, but some brands (such as Huadi) have not used this technology. This kind of stove usually uses a battery, which only participates in ignition and does not participate in the work of solenoid valves.
The second is ion extinguishing technology, which is a battery-driven extinguishing mechanism based on flame conduction principle. When the knob is lifted, the pulse igniter discharges, while the solenoid valve quickly sucks in, the gas path opens, and the gas enters the combustion chamber and completes the ignition.
When the flame burns, the micro-current attached to the induction needle forms a circuit through the flame, the furnace head and the bottom shell. The pulse transmits the "hold" command to the solenoid valve continuously, and the gas can be supplied continuously. If the flame is extinguished, the feedback circuit is interrupted, the solenoid valve is released immediately, and the gas path is cut off.
Ion induction technology is mostly used in infrared ovens. It usually requires two batteries to drive solenoid valves (mainly full absorption). Compared with the former, ion induction technology is relatively mature, and there is basically no aging problem, but the cost is slightly higher than that of thermocouple technology.
The response time of thermal couple technology extinguishing protection is long, mostly in 15-45 seconds, because of the poor sensitivity of the technology. In order to prevent the protection caused by accidental extinguishing, the system added delay design on the single chip computer. Ion induction technology also adds a delay, but only between 1 and 4 seconds.
As an aside, Chinese people still recognize advertisements. Infrared cookers have surpassed ordinary cookers in technology, but infrared technology is a rising technology, so it has been in the downwind of the market.