Means and method for controlling load turndown in a fluidized bed combustor
AssigneeIowa State University Research Foundation, Inc.
InventorsRobert C. Brown, William H. Buttermore
Life of this patent
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Abstract
A means and method of controlling the load turn-down in a fluidized bed combustor including a fluidized combustion bed having an independent fluidization air source. A separately fluidizable heat transfer bed surrounds the fluidized combustion bed. By independently adjusting the fluidization of the heat transfer bed, the load turn-down of the fluidized bed combustor can be accurately and efficiently controlled. In an alternative embodiment, one or more heat transfer beds are positioned in and surrounded by the combustion bed. Conduits are then positioned within the heat transfer beds to carry a circulating and heat-conducting medium therethrough.
Claims9
A method of controlling the load turn-down in a fluidized bed combustor comprising the steps of:
- combusting fuel in a fluidized combustion bed;
- positioning and separately fluidizing non-combustible particle
- material and free combustible material in one or more heat transfer beds positioned
- within the fluidized combustion bed;
- positioning and circulating a heat conducting and absorbing
- medium through each heat transfer bed;
- and adjusting the fluidization of the heat transfer bed to
- control the load turn-down.
A fluidized bed combustor for improving the control of load turn-down comprising:
- a first chamber defining a fluidized combustion bed containing fuel and combustion bed material to be fluidized and to contain the combustion process;
- one or more second chambers each defining a separately fluidizable heat transfer bed containing non-combustible fluidized particulate material and free of cumbistable material each said second chamber being surrounded at least in part by said first chamber, each said second chamber having a heat conducting means;
- so that by controlling the fluidization of each said heat transfer bed separately from the combustion bed, the load turn-down of a fluidized bed combustor can be accurately controlled.
Dependencies are inferred from the claim text.