Outokumpu Oy

Pentti O Hokkanen

Lauri A Mustikka

Launo L Lilja

Matti E Honkaniemi

Risto M Heikkila

Martti J Jankkila

Frans H Tuovinen

Aimo A Nurminen

Matti A Virta

The present invention relates to a method and apparatus for preparing a feed mixture, made of several batch components, at one stage in order to feed it into a smelting furnace. The preparation of the batch may include the preheating and drying of the material, the removal of crystal waters and evaporable substances as well as the conduction of the batch into the smelting furnace. According to the invention, a hot inert gas is conducted through a downwards settling batch so that the gas is mixed into the batch as well as possible, but even partial fluidization is prevented. The apparatus of the invention comprises a pretreatment silo (6) which is uniform at the upper part but is divided into several sub-silos (7) at the lower part. At the lower part of the sub-silos there are connected ducts (8) wherealong the batch flows into the smelting furnace (9) located below the pretreatment silo (6). In between the sub-silos (7) there is located the gas distribution chamber (34), wherefrom the gases are distributed through the distribution ducts (35) extending to the sub-silos and the gases are discharged at the top (41) of the silo (6). The employed gas is obtained by means of burning the exhaust gases (10) from the smelting furnace and by combining them with cleaned circulation gases (25).

Apparatus for batch preparation and feeding into the smelting process

The present invention relates to a method and apparatus for preparing a feed mixture, made of several batch components, at one stage in order to feed it into a smelting furnace. The preparation of the batch may include the preheating and drying of the material, the removal of crystal waters and evaporable substances as well as the conduction of the batch into the smelting furnace. According to the invention, a hot inert gas is conducted through a downwards settling batch so that the gas is mixed into the batch as well as possible, but even partial fluidization is prevented. The apparatus of the invention comprises a pretreatment silo (6) which is uniform at the upper part is divided into several sub-silos (7) at the lower part. At the lower part of the sub-silos there are connected ducts (8) wherealong the batch flows into the smelting furnace (9) located below the pretreatment silo (6). In between the sub-silos (7) there is located the gas distribution chamber (34), wherefrom the gases are distributed through the distribution ducts (35) extending to the sub-silos and the gases are discharged at the top (41) of the silo (6). The employed gas is obtained by means of burning the exhaust gases (10) from the smelting furance and by combining them with cleaned circulation gases (25).

Method and apparatus for batch preparation and feeding into the smelting

A brickwork construction is disclosed as specifically useful for making the gas distribution chamber of a shaft kiln. In this construction the collapse of the wall into the shaft kiln is prevented by using bricks which are thinner at one end than the other and are laid to make a wall in which there is a straight inner surface to the shaft kiln and an arched side to the gas distribution chamber.

Brickwork construction

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Tornio, Finland

Pentti O Hokkanen