Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F22—STEAM GENERATION
  • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
  • F22B31/00—Modifications of boiler construction, or of tube systems, dependent on installation of combustion apparatus; Arrangements of dispositions of combustion apparatus
  • F22B31/0007—Modifications of boiler construction, or of tube systems, dependent on installation of combustion apparatus; Arrangements of dispositions of combustion apparatus with combustion in a fluidized bed
  • F22B31/0084—Modifications of boiler construction, or of tube systems, dependent on installation of combustion apparatus; Arrangements of dispositions of combustion apparatus with combustion in a fluidized bed with recirculation of separated solids or with cooling of the bed particles outside the combustion bed
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
  • F23C10/00—Fluidised bed combustion apparatus
  • F23C10/02—Fluidised bed combustion apparatus with means specially adapted for achieving or promoting a circulating movement of particles within the bed or for a recirculation of particles entrained from the bed

Definitions

• the invention relates to a fluidized bed combustion system with solids recirculation, with a combustion chamber, at least one solids separator connected downstream of the combustion chamber on the flue gas side, one flue gas duct downstream of the solids separator and at least two secondary heating surfaces in the flue gas duct.
• a fluidized bed combustion system is known from WO 83/03294, in which a labyrinth separator is arranged at the upper end of the combustion chamber in such a way that the separated solids fall into a separate storage room and the flue gas enters a falling flue gas flue.
• the applicant of the present invention proposed an arrangement in which the labyrinth separator is arranged directly in the upper region of the combustion chamber, and this leads the separated solids onto at least one wall surface on which the solids are covered or not covered - drain down.
• This object is achieved in that at least a portion of the flue gas flue with at least one secondary heating surface, preferably superheater, is arranged above the combustion chamber to form a structural unit with the latter.
• a partition is arranged between the partial section of the flue gas flue and the combustion chamber, below which the flue gas laden with solids can be removed from the combustion chamber and above which the flue gas is at least an outside cyclone cleaned flue gas can be introduced into the section.
• the partition is preferably arranged at an incline in order to be able to remove the flying dust which is still settling out of the flue gas and which is not also separated in the solids separator.
• a structure comparable to the tower boilers of other types of firing can be achieved if a large number or all of the secondary heating surfaces are arranged in the flue gas duct above the firing chamber.
• Solids separator and a flue gas flue which also has a falling section
• FIG. 2 shows an embodiment of the furnace, in which all secondary heating surfaces are arranged in a section of the flue gas flue, which forms a structural unit with the furnace,
• FIG. 3 shows an embodiment comparable to FIG. 1, but with an internal labyrinth separator and
• FIG. 4 shows an embodiment comparable to FIG. 2 with an internal labyrinth separator.
• a combustion chamber (1) and a first section (2) of a flue gas flue (3) connected downstream of the combustion chamber are combined to form an assembly.
• section (2) is switched on as an evaporator in the water-steam circuit of the combustion system.
• the dashed circles indicate, however, that the upper part of the wall pipe can also be switched as an overheat.
• a secondary heating surface (5) preferably connected as a superheater heating surface, is arranged.
• the combustion chamber (1) is separated from the section (2) by an inclined partition. Flue gas laden with solids is drawn off below the partition (6) and fed to a solids separator, preferably a cyclone (7). The separated solid is fed into the combustion chamber above the fluidized bed (8).
• the cyclone (7) shown in FIG. 1 is tubular; however, it is also possible to use a brick cyclone.
• the flue gas cleaned from the solid enters the section (2) above the partition (6) and is deflected towards the secondary heating surface (5).
• the floor is inclined to one side and the solid is drawn off via appropriate devices, as is shown schematically by the arrow (9). From the subsection
• the flue gas enters a falling section (10) of the flue gas flue, in which further secondary heating surfaces (11) and (12) are arranged.
• the post-heating surface (11) can be connected, for example, as a feed water preheater and the post-heating surface (12) as an air preheater.
• the present invention is not limited to the division and assignment of the secondary heating surfaces described above.
• solids are separated on a labyrith separator (13) that separates the combustion chamber (1) from the flue gas section (2).
• the separated solids are discharged to the left in FIG. 3 from the individual gutters (14) and in the shafts (15) derived down into the firebox.
• FIGS. 1 to 4 From the description of FIGS. 1 to 4 it can be seen that by arranging at least one secondary scarf in a flue gas duct section which represents a structural extension of the combustion chamber, an extremely compact construction of the combustion system is achieved, the combustion chamber pipe and the pipe section of the section also being a functional unit form, such as form the usual screw winding of a BENSON boiler.
• Fuel and air supply are not shown in the figures for the sake of simplicity. For this, e.g. reference is made to the prior art mentioned in the introduction to the description.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Fluidized-Bed Combustion And Resonant Combustion (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6320295

Family Applications (1)

Country Status (5)

Families Citing this family (1)

Family Cites Families (9)

• 1987
  • 1987-02-05 DE DE3703471A patent/DE3703471A1/de not_active Ceased
• 1988
  • 1988-02-03 EP EP88901266A patent/EP0309492A1/de not_active Withdrawn
  • 1988-02-03 WO PCT/EP1988/000078 patent/WO1988005887A1/de not_active Application Discontinuation
  • 1988-02-04 ZA ZA88790A patent/ZA88790B/xx unknown
  • 1988-02-05 ES ES8800324A patent/ES2006552A6/es not_active Expired

Non-Patent Citations (1)

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