Fluidized bed boiler with bed drain ash cooling and transfer

摘要

A fluidized bed boiler bottom with an ash cooling and removal system has a water-cooled tube panel floor with fluidization bubble caps above a windbox, and a structural support and at least one hopper, each of the at least one hoppers with a bed ash cooler region and drain control system positioned beneath the tube panel floor. The hoppers are formed from cooled enclosure tubes and have sloped upper walls and lower troughs having vertical walls. Standpipes are provided through the tube panel floor down into the troughs at the bottoms of the hoppers. The standpipes may be arranged in an H-pattern in the tube panel floor and subsequently channel several flowpaths together into fewer standpipes closer to the troughs. Solids flow through the standpipes is controlled by operation of fluidizing nozzles located underneath the standpipes. Pulsing the flow of air through the fluidizing nozzles prevents or allows solids to flow through the standpipe from the bed. Some cooling air may flow up through the standpipes, cooling solids in the standpipes.