| OCR Text |
Show The wide variations of fuel flow with time shown in Figure 2, while acceptable for transport of fuel from one bin to another is totally unacceptable for a pulverized coal burner. For this reason, significant research was needed to develop a storage, metering, and modified dense phase transport system that was capable of supplying uniform fuel flows to the burner over the range of operating rates encountered in a commercial application. As part of the development of the DIPC system, C-E conducted an extensive research program to develop a dense phase fuel supply and firing system. The following is a review of this development, which can be categorized: Coal storage Bin feeding Coal metering Coal transport Coal splitting Coal Storage: The practice of storing pulverized coal in bins has gone on for nearly fifty years, but not without problems. The one major storage problem that has repeatedly plagued bin systems is bin fires. C-E gained significant experience in this area during this development effort. We have confirmed that the single most important factor in preventing bin fires is the prevention of air infiltration into the bin both while in use or in stagnant storage. Pulverization of coal using flue gas is also recommended and use of gas inerting systems can also be considered. Our procedure for inerting pulverized coal bins has been to simply seal the bin with valves or slide gates or other positive seal devices. Oxygen both above the coal and trapped between the individual coal particles is slowly consumed to form CO and C09. (While CO is combustible, 11-7 |
