For safety needs, gas stove flameout protection device is very necessary, the relevant national standards also have mandatory provisions.
There are three kinds of flame protection methods used in the market: heat-sensitive, thermoelectric and photoelectric. Heat-sensitive: Also known as dual-metal sheet. The bimetallic sheet is made of two different kinds of metal with various expansion coefficients, under the effect of temperature, the expansion coefficient of the metal side will be small expansion coefficient of the metal side bending, when the loss of temperature, the original expansion of the bending metal will slowly revert to the original state, so the bimetal is also known as memory alloy.
The double metal plate is used as a safety protection device for the sensor, it is the double metal plate in the temperature of the expansion and bending characteristics. The advantages of Bimetal protection device are simple structure and low cost.
Shortcomings are difficult to install, the installation of bimetal pieces of the position and plug valve and gas valve with a high demand, and thermal inertia, open and closed valve for a long time, short service life. Thermoelectric type: The device is also the use of gas combustion when the heat generated. Thermoelectric flameout safety protection device consists of two parts of thermocouple and solenoid valve, the thermocouple is composed of two kinds of different alloy materials.
Different alloy materials under the action of temperature will produce different thermoelectric potential, the thermocouple is the use of different alloy materials in the temperature of the thermoelectric potential produced by different manufacturing, it uses the different alloy materials heating difference. The thermoelectric safety protection device has been widely used because of its simple structure, convenient installation and low cost.
But this kind of protection device takes the thermocouple as the thermal sensor, the shortcoming is the heat inertia is big, the reaction speed is slow, causes the person to feel the operation is inconvenient, and the service life is short, the plug valve and the solenoid valve match installs the precision request to be high. Photoelectric type: Also known as Ion-induction. The device is to use the gas in the combustion of flame with ions and has unidirectional conductivity characteristics.
This security method was first used in gas water heaters, and has been developed from DC induction to AC induction, so that the reliability has been greatly improved, applied to the cooker has only three or four years of