The problems of coal-awning in raw coal bunker and explosion in coal pulverizing system during test period of mixedly burning brown coal in a 410 t/h boiler of one power plant have been analysed and studied.It is believed that the main causes are as follows:the small cross area of coal-dropping outlet from the raw coal bunker

the low coal-level in and low ambient temperature near the said bunker

and the operation method for pulverizing bituminous coal is continuously used in start-up and shutdown of the coal pulverizing system.For these

some measures have been adopted

namely adding the rapping mechanism

shortening the time interval for coal loading into the said bunker

lengthning the purging time afters hutdown of the coal pulverizer etc..After implementation

the above-mentioned problems have been solved

making the amount of mixedly burning brown coal to reach 31.6%

not only saving the fuel cost

but also alleviating the passive situtation of forced shutdown in operation of unit due to shortage of bituminous coal

ensuring the normal operation time of unit.