General:
Burning stability and economy of boilers in coal power plant is closely associated with coal concentration and homogeneity. The coal concentration and the powder homogeneity of coal burner directly influences stability of working condition and burning rate of boiler.
PFC-I coal concentration online measuring device is produced based on charge induction detection principle. It can measure coal concentration and speed with characteristics of actual measurement, fast reaction and convenient installation and free of maintenance. Measured value provide stringent reference for operator to adjust burning speed.

Measurement principle:
It is normal that coal collides, scrubs and separates with pipe wall, also it is the same with powder grains during the process that coal is milling and grinding to coal grains and coal gas conveying process. Great quantity contiguity and separation bring quite quantity static charge to powder.
While charged articles produces certain electrostatic field. When charged coal articles going through metal inductive probe, equal quantity inductive charges on the surface of probe which is in electrostatic field. Inductive current appears on probe when quantities of live coal. The current amount is associated with coal quality flowed through probe. Take corresponding signal as measurement signal, then make treatment and analysis to it so as to get coal concentration signal.

Functions:
1. Real-time on-line measurement of slack concentration and flow in primary wind powder pipe.
2. Real-time on-line measurement of slack flow speed in primary wind powder pipe.
3. Real-time display function of bar graph, curve and simulated graph.
4. Storage, inquiring, printing and report forms of historical data.
5. Auxiliary diagnosis of phenomenon of blocking, cutting and depositing of slack in primary wind powder pipe.
6. Auxiliary diagnosis of slack flow balance of every primary wind powder pipes.
7. Beyond limit alarm of concentration and speed.
8. Long-distance monitoring and diagnosis of on-the-spot equipment.
9. Interface function of user's data.

System composition:
PFC mainly consists of front sensor, signal adjusted unit and collecting calculating unit. Sensed by sensor, adjusted by signal adjusting unit, original signal is sent to main controlling computer which collects and analyses signal, then the result is got and sent to DCS.

Features:
1. Passive sensor. Adopting passive charge sensor, compared with other active sensors adopting microwave, the sensor itself doesn't produce any measurement error and electric danger caused by instable measurement source. Meanwhile, passive device is difficult to be damaged, so it has higher measurement accuracy and stability.
2. Fast measurement without delay. Charge migration measurement. System reflects signal changing as fast as speed of electromagnetic, so it responses fast without delay.
3. Charge induction technology measurement without being cleaned.

Application areas:
It can be widely used in lump-sum measurement of slack concentration of storage powder-producing system, direct blowing powder-producing system and other systems.