Abstract: A gas temperature control system for maintaining a desired economizer outlet gas temperature across a range of boiler loads comprises a plurality of tubular configurations having surfaces that are in contact with the flue gas. Each tubular configuration, preferably, comprises a plurality of serpentine or stringer tubes arranged horizontally or vertically back and forth within the economizer, and each tubular configuration having a separate feedwater inlet. Heat transfer from the flue gas is accomplished by controlling the feedwater flow rates through the tubular configurations. In a temperature control system having two tubular configurations, the overall heat transfer capacity of the economizer may be reduced to maintain the desired economizer outlet gas temperature during low boiler loads by reducing feedwater flow through one tubular configuration and by overflowing the other tubular configuration, such that total flow of feedwater through the economizer is maintained substantially constant.

Abstract: A radiant syngas cooler used to contain and cool the synthesis gas produced by coal gasification processes employs radiant and convection surfaces in a specific arrangement to achieve a cost-effective, compact design.

Abstract: A flow enhancing arrangement for ducts such as rectangular flue ducts wherein a series of tear shaped foils are spacedly mounted in the duct extending from top to bottom thereof and where a series of diamond shaped vanes also extending from the top to the bottom of the duct are spacedly mounted between the tear shaped foils to provide a more uniform flow distribution and to lower the pressure thereby. A series of baffles extending from both the tear shaped foils and the diamond shaped vanes may also be used.

Abstract: A dual pressure boiler system has a bottom furnace that operates as a low pressure natural steam generating system and a top furnace that operates as a high pressure natural steam generating system. The low pressure natural steam generating system has a low pressure steam drum, a first pump for providing feed water to the low pressure steam drum, and a low pressure superheater fluidly connected to the low pressure steam drum. The high pressure natural steam generating system has a high pressure steam drum, a second pump for providing feed water to the high pressure steam drum, and a high pressure superheater fluidly connected to the high pressure steam drum.