Babcock & Wilcox Power Generation Group, Inc.

The Babcock & Wilcox Company

Mark C Godden

Mikhail Maryamchik

Kiplin C Alexander

David L Kraft

David E James

Paul S Weitzel

Ted V Mull, Jr

Paul S Larsen

David L Karaft

A circulating fluidized bed (CFB) boiler includes a reaction chamber, where a bubbling fluidized bed (BFB) is contained within an enclosure within the lower portion of the reaction chamber and contains an in-bed heat exchanger (IBHX) that occupies part of the reaction chamber floor. A plurality of in-bed secondary air nozzles comprise a plurality of tubes which are grouped together and run across the width of the BFB between the BFB enclosure wall and an outside wall of the CFB. The nozzles are positioned to prevent the deflection of solids falling onto the BFB from the CFB by the secondary air jets while avoiding a complicated structure that would interfere with gas and/or solids movement in the furnace. The nozzles' exit openings are flush, or almost flush, with the BFB enclosure wall.

Circulating fluidized bed (CFB) with in-furnace secondary air nozzles

A system for feeding a primary oxidant to an oxy-fired circulating fluidized bed (CFB) boiler. The system includes a plurality of bubble cap assemblies each comprising a stem and a bubble cap with at least one exit hole, each bubble cap connected via a stem to at least one windbox, the windbox containing at least one manifold. A plurality of pipes are provided, each pipe located within a bubble cap assembly with an open end located either at, above or below the exit holes of the bubble caps and an opposite end connected to the manifold located inside each windbox. Recycle gas is piped into the windbox, to the stem, and exiting from the exit holes located in the bubble cap into the CFB. Oxygen is piped into the manifold, through the pipes and exiting through the exit holes located in the bubble cap. The pipe may further contain means placed at its open end, to prevent accidental inlet of hot particles into the pipe, such as a debris shield placed above and proximate to the open end of the pipe or by having the open end oriented in a downward direction. An insulating gap may also be placed inside the bubble cap to reduce thermal conductance between the bubble cap outer surface that is exposed to hot bed material and the inner surface of the bubble cap, being in contact with oxygen.

Primary oxidant feed to oxy-fired circulating fluidized bed (CFB)

A circulating fluidized bed (CFB) boiler comprising a reaction chamber. A bubbling fluidized bed (BFB) is contained within an enclosure within the lower portion of the reaction chamber and contains an in-bed heat exchanger (IBHX) that occupies part of the reaction chamber floor. At least one non-mechanical valve, which includes an opening between the CFB and BFB and independently controlled fluidizing means located both upstream and downstream of the opening, is used to control the heat transfer to the IBHX by controlling the solids discharge from the BFB to the CFB. The elevation of the bottom of the opening is at or above the elevation of the fluidizing means. A flow control barrier may be located downstream of the opening.

In-bed solids control valve

A combined, integral steam generator coal gasifier includes a vertically elongated, all welded, gas tight enclosure with a burner zone having a double pitch sloping furnace floor and a slag tap extending therethrough. Successive zones located above the burner zone are provided with appropriate tube materials for conveying synthesis gas produced by the coal gasification process. A multi-pass convection pass zone having upflow and downflow passes is located at an upper portion of the enclosure and contains a plurality of superheater (primary and secondary) as well as economizer heating surfaces which extract heat from the synthesis gas to produce steam. An ash remover is connected to the outlet of the convection pass zone to remove ash from the synthesis gas exiting from the convection pass zone. The slag tap located at the bottom of the burner zone communicates with a slag tank or a drag chain deasher for receiving and removing slag from the burner zone.

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Mogadore, OH, United States of America

Mark C Godden