Fludized bed combustion system and process for operating same
AssigneeFoster Wheeler Energy Corporation
InventorsDavid H. Dietz, Walter R. Campbell
Life of this patent
Estimating the term…
Abstract
A fluidized bed combustion system and process is disclosed, in which full load stoichiometry is maintained at lower loads. The system and process includes an enclosure and a partition disposed in the enclosure to define a furnace section and an overfire air plenum section. A bed of combustible particulate material is formed in the furnace section and air is passed into the bed in quantities sufficient to fluidize the material and insufficient to completely combust the material. Overfire air is passed into the overfire air plenum, through control dampers in the partition and into the furnace section in quantities sufficient to completely combust the material.
Claims15
A fluidized bed combustion system comprising:
- an enclosure;
- a partition disposed in said enclosure to define a furnace section and an overfire air plenum section, said partition having a plurality of openings and a corresponding plurality of ducts registering with said openings;
- a bed of combustible particulate material formed in said furnace section;
- means for passing air into said bed in quantities sufficient to fluidize said material and insufficient to completely combust said material;
- means for passing overfire air into said overfire air plenum, through said ducts and into said furnace section in quantities sufficient to completely combust said material;
- and
- a damper associated with at least one of said plurality of ducts for regulating the flow of said overfire air into said furnace section.
A fluidized bed combustion process comprising the steps of:
- supporting a bed of combustible material in a furnace section;
- passing air into said bed in quantities sufficient to fluidized said material and insufficient to completely combust said material;
- passing overfire air into an overfire air plenum, through a plurality of ducts, and into said furnace in quantities sufficient to completely combust said material;
- and
- regulating the passage of said overfire air through said ducts and into said furnace section.
A fluidized bed combustion process comprising the steps of:
- supporting a bed of combustible material in a furnace section;
- passing primary air into said bed in quantities sufficient to fluidized said material and insufficient to completely combust said material;
- passing secondary air into an overtired air plenum, through a plurality of ducts, and into said furnace section;
- establishing a predetermined ratio of primary air to secondary air so that said material is completely combusted;
- discharging a mixture of flue gases and entrained material from said furnace section;
- separating said entrained material from said flue gases;
- circulating said separated material back to said furnace section;
- operating said furnace at relative low loads whereby said circulation is reduced;
- and
- regulating the flow of secondary air through said ducts and into said furnace section in a manner so that, at said relatively low loads, said ratio is maintained while said reduction is less than it would be without said step of regulating.
Dependencies are inferred from the claim text.