Rotary continuous ash discharge stoker

In a rotary stoker or the like having a grate on which burning fuel is supported, means to admit air from below the grate to said fuel, and an inner wall forming a furnace combustion chamber, an improved air supply system comprising:

• a central stationary section and an outer rotating ring forming said grate and defining a continuous fuel supporting surface across said central section and outer ring;
• means for admitting air to said fuel from below said grate at locations throughout said continuous fuel supporting surface;
• at least one compartment located directly under said grate to supply pressurized air to the fuel through said grate;
• a compartment located above said grate along said inner wall to supply pressurized air to said chamber above said grate;
• air supply means to supply pressurized air to said compartments;
• means to separately control the air pressure supplied to each compartment.

A rotary stoker comprising:

• a housing having an inner wall forming a furnace combustion chamber;
• support means located within said housing to support burning fuel, comprising
• a circular grate having a continuous fuel supporting surface for burning fuel comprising a central stationary section and an outer rotating ring,
• said central stationary section being of a generally hollow frusto-conical configuration having a plurality of tuyeres disposed in said section,
• said tuyeres being directed generally radially outwardly, and
• said outer rotating ring concentric with said central section and located radially outwardly of said central section;
• means to supply pressurized air into said housing below said circular grate throughout the extent of said continuous fuel supporting surface;
• a plurality of air plenums formed below said circular grate, connected to said air supply means, to supply pressurized air to said tuyeres, said grate forming one wall of each said air plenum;
• and
• drive means to drive said outer ring of said circular grate.

A rotary stoker comprising:

• a housing having an inner wall forming a furnace combustion chamber:
• support means located within said housing to support burning fuel, comprising
• a circular grate having a central stationary section and an outer rotating ring,
• said central stationary section being of a generally hollow frusto-conical configuration having a plurality of tuyeres disposed in said section with at least one set of tuyeres disposed near the base portion of said section,
• said tuyeres being directed generally radially outwardly, and
• said outer rotating ring being concentric with said central section and located radially outwardly of said central section;
• means to supply pressurized air into said housing below said circular grate;
• a plurality of air plenums formed below said circular grate, connected to said air supply means, to supply pressurized air to said tuyeres, including a plurality of air plenums formed under said central stationary section, said grate forming one wall of each said air plenum, wherein at least one plenum communicates with the base portion of the central stationary section in which the tuyeres are located and at least one other plenum communicates with the other portion of the central stationary section;
• and
• drive means to drive said outer ring of said circular grate.

In a rotary stoker, including a furnace housing and a rotating grate, which stoker produces particulate filter means as residue during its operation, an improved seal between the inner wall of said furnace housing and said grate comprising:

• a downwardly extending flange disposed at one of the outer periphery of said rotating grate or said inner wall of said furnace housing;
• an annular trough disposed along the other of the outer periphery of said grate or said inner wall, at least a portion of which is disposed below the outer periphery of said rotating grate and communicates with the upper surface of said grate;
• and
• means for directing said particulate filler means into said trough during the operation of said stoker,
• the lower edge of said downwardly extending flange being disposed below the top level of said filler means along the entire periphery of said rotating grate,
• whereby a seal is maintained between the outer periphery of said grate and the inner periphery of said housing wall.

A rotary stoker comprising:

• a housing having an inner wall forming a furnace combustion chamber;
• support means located within said housing to provide a continuous surface to support burning fuel and passage means for passing air from below said support means to said fuel at positions throughout the extent of said continuous surface of said grate, comprising:
• a circular grate having a central stationary section and an oute rotating ring to provide said continuous fuel supporting surface, said outer rotating ring being concentric with said central section and disposed radially outwardly of said central section;
• means to supply pressurized air into said housing below said circular grate;
• a plurality of air plenums formed below said circular grate, connected to said air supply means, to supply pressurized air to said fuel through said passage means, said grate forming one wall of each said air plenum;
• drive means to drive said outer ring of said circular grate;
• and
• means for sealing said grate at said inner wall;
• wherein fuel is fed to the center of said support means, ash residue exits at the radially outer edge of said support means and said combustion chamber is sealed from said air plenums except for pressurized air passing from said air plenums to said combustion chamber through said passage means of said support means.

A furnace comprising:

• (a) an inner wall forming a furnace combustion chamber;
• (b) a grate disposed in said combustion chamber for supporting burning fuel, said grate comprising a central stationary section and an outer rotating ring, said grate having a fuel supporting surface across said central section and outer ring;
• (c) a first compartment located directly under said grate for supplying pressurized air through said grate to the fuel supported thereon;
• (d) a second compartment located above said grate along said inner wall for supplying pressurized air to said combustion chamber above said grate;
• (e) air supply means for supplying pressurized air to both of said compartments;
• (f) means for separately controlling the air supplied to each of said compartments;
• (g) first annular means disposed on said inner wall and second annular means disposed about the periphery of said rotating ring, wherein one of said first and second annular means overhangs the other of said first and second annular means to form a seal.