BALANCING OF COAL FLOW TO BURNERS IN PULVERIZED COAL BOILERS

摘要

This paper deals with the development of a technology for making on-line adjustments to the coal flow rates to individual burners. The method makes use of a riffler installed in the splitter box with adjustable flow control elements positioned upstream of the riffler. The approach is applicable to piping systems with splitters in which a single pipe is split into two, three or even four pipes. Laboratory results are presented for two-, three-, and four-way splitters, demonstrating the ability to achieve balanced coal flow rates among the outlet pipes. As the results show, this can be done without affecting the distribution of primary air, which is necessary for achieving balanced burners. With this approach, burner balancing would be carried out in three steps. First, the primary air flows would be balanced using orifices located in the coal pipes. The coal flow rates would then be balanced using the adjustable flow control elements; and finally, the secondary or auxiliary air registers would be adjusted to balance the overall fuel-to-air ratio at the burners.