High pressure feeder and method of operating to feed granular or fine materials

摘要

A coal feed system to feed pulverized low rank coals containing up to 25 wt % moisture to gasifiers operating up to 1000 psig pressure is described. The system includes gas distributor and collector gas permeable pipes imbedded in the lock vessel. Different methods of operation of the feed system are disclosed to minimize feed problems associated with bridging and packing of the pulverized coal. The method of maintaining the feed system and feeder device exit pressures using gas addition or extraction with the pressure control device is also described.

主权项

1. A method of using a coal feeder system comprising a coal surge bin configured to store processed coal for feeding into a gasifier; a lock vessel coupled to the coal surge bin, the lock vessel being a pressure swing device; a gas collector and distributor disposed within the lock vessel, the gas collector and distributor configured to distribute gas within the lock vessel; a gas permeable membrane disposed within a conical section of the lock vessel; a feed vessel coupled to the lock vessel, the feed vessel configured to operate at a substantially constant pressure; a pressure control device programmed to maintain a substantially constant pressure between the feed vessel and a gasifier; and a feeder device configured to control a coal feed rate into the gasifier, the method comprising the steps of:
loading the lock vessel with pulverized coal; pressurizing the lock vessel by a slow pressurization step for up to about sixty seconds; pressurizing the lock vessel by a fast pressurization step till the pressure is within about 5% of a final desired pressure; and pressurizing the lock vessel by a slow pressurization step until a final desired pressure is reached.