Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
  • C22B1/00—Preliminary treatment of ores or scrap
  • C22B1/14—Agglomerating; Briquetting; Binding; Granulating
  • C22B1/16—Sintering; Agglomerating
  • C22B1/20—Sintering; Agglomerating in sintering machines with movable grates
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
  • C22B1/00—Preliminary treatment of ores or scrap
  • C22B1/14—Agglomerating; Briquetting; Binding; Granulating
  • C22B1/24—Binding; Briquetting ; Granulating
  • C22B1/2413—Binding; Briquetting ; Granulating enduration of pellets
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27B—FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
  • F27B21/00—Open or uncovered sintering apparatus; Other heat-treatment apparatus of like construction
  • F27B21/06—Endless-strand sintering machines

Definitions

• the object of the invention is to optimize the heat utilization when drying the green pellets and to achieve a uniform drying of the pellets.
• the object is achieved by a pelletizing system with a first conveyor for applying a first layer of green pellets to a wall grate at a first location, with a second conveyor for applying a second layer of green pellets to the first Layer at a second point lying behind the first point in the direction of movement of the wall grate, with a device for pre-drying the pellets of the lower layer lying between the two points and with a further drying device behind the second point, at least in the further drying device a gaseous heat transfer medium flows through the pellet layers from top to bottom.
• the invention is based on the following knowledge.
• a gaseous heat transfer medium flows through a two or more layers of green pellets from top to bottom, the drying of the lower layer is caused by the moisture initially expelled from the upper layer and the outlet which is impeded by the traveling grate and the protective layer which may be thereon of the heat transfer medium is delayed from the lower layer.
• the pellet layers are flowed through from bottom to top, the heat transfer medium can emerge unhindered from the uppermost pellet layer after absorption of the moisture, so that drying takes place better; a disadvantage here, however, is the unnecessary heating of the traveling grate and the protective layer which may be located thereon.
• the lower layer is pre-dried, the heat transfer medium then flowing through both layers from top to bottom, so that on the one hand a more effective and more uniform drying of both layers is achieved and on the other hand the traveling grate and optionally protective layer lying thereon is not unnecessarily heated.
• a gaseous heat transfer medium flows through the first layer from top to bottom.
• the first conveying device leads counter to and the second conveying device inclines in the direction of the movement of the traveling grate from top to bottom towards the moving grate.
• the predrying device can thus advantageously be accommodated in the space delimited by the two conveying devices and the wall grate.
• the drawing shows the part of a pelletizing plant that is relevant for explaining the invention.
• fine ores are rolled into spherical packs with the addition of water and additives.
• the green pellets 1 obtained in this way are supplied in approximately equal parts to a first conveyor device 2 and a second conveyor device 3, which are each designed as roller conveyors and bring about a uniform distribution of the green pellets 1 transversely to the conveying direction.
• the first conveying device 2 leads obliquely downwards to a traveling grate 4 which is already covered with a protective layer 5 of burned pellets.
• the direction of movement 6 of the moving grate 4, which is designed as an endless belt conveyor, and that of the first conveyor 2 are opposite to each other.
• the green pellets 1 coming from the first conveyor 2 are deposited on the traveling grate 4 with the protective layer 5 lying thereon at a first point 7, forming a first pellet layer 8 about 200 mm thick.
• the second conveyor 3 leads obliquely downwards in the direction of movement 6 of the traveling grate 4 and deposits the green pellets 1 at a second location 9, forming a second pellet layer 10 on the first pellet layer 8.
• the second layer 10 also has a thickness of approximately 200 mm.
• a pre-drying device 11 is arranged above the wall grate 4 and below the conveyors 2 and 3, in which a gaseous heat transfer medium 12, here heated air, flows through the first pellet layer 8 from top to bottom and so on predried.
• the air is drawn off under the traveling grate 4.
• a further drying device 13 is arranged behind the storage location 9, in which a gaseous heat transfer medium 14, here heated air, flows through both pellet layers 10 and 8 from top to bottom. Behind the drying device 13 there are further devices 15 for heating, burning and cooling the pellets on the wall grate 4 in a known manner.
• the first pellet layer 8 is pre-dried to such an extent that in the further drying device 13, despite the moisture emerging from the upper second pellet layer 10 downwards into the first layer 8, both layers 10 and 8 are evenly dried . Since the heat transfer medium 12 or 14 flows from top to bottom through the layers 10, 8 and 5 and the moving grate 4, the moving grate 4 and the protective layer 5 are not unnecessarily heated. All in all, optimal heat utilization and even drying of the pellets is achieved.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• Geochemistry & Mineralogy (AREA)
• Geology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Manufacturing & Machinery (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Materials Engineering (AREA)
• Environmental & Geological Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• General Engineering & Computer Science (AREA)
• Manufacture And Refinement Of Metals (AREA)
• Drying Of Solid Materials (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=7759378

Family Applications (1)

Country Status (6)

Cited By (1)

Families Citing this family (1)

Citations (3)

Family Cites Families (1)

• 1995
  • 1995-04-10 DE DE19513550A patent/DE19513550B4/de not_active Expired - Fee Related
• 1996
  • 1996-03-20 AU AU49385/96A patent/AU692371B2/en not_active Ceased
  • 1996-03-20 WO PCT/DE1996/000480 patent/WO1996032511A1/de active Search and Examination
  • 1996-03-20 MX MXPA97007815A patent/MXPA97007815A/es unknown
  • 1996-04-01 ZA ZA962582A patent/ZA962582B/xx unknown
  • 1996-04-04 IN IN622CA1996 patent/IN187966B/en unknown

Patent Citations (3)

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