Pulverized coal burner flame detector Classification and performance

There are many kinds of flame detector, according to the working principle can be classified as follows:
1. the principle of thermal expansion. Metal, liquid and so on, under the action of flame high temperature expansion, as a pulse signal. Direct or amplification effect on the actuator.
2. the use of hot spots. Thermocouple at high temperature under the action of the electric potential, after amplification of the role in the implementation of the mechanism.
3. using the principle of sound power, that is, the characteristics of the disturbance noise during combustion.
4. using the principle of pressure around the flame. The change in the pressure around a flame signal. Also available differential pressure transmitter the bellows and the furnace chamber pressure difference transform for signal of opening and closure of the contacts, turned into a flame detection signal.
5. the principle of flame conductivity. Combustion chemical reaction to make flame ionization to produce conductivity, sensitive element to an electrode placed directly in the flame, and the other electrode connected on the furnace shell, combustion is current through a two electrode. This pulse signal amplification, so that the relay action.