Smelting unit with furnace rocking cradle

A smelting unit having first and second tiltable melting furnaces (10/1, 10/2), each of which is provided with a furnace gas discharge (21/1, 21/2) connected to a disposal conduit system (48, 49, 50),

• a heating means (28) arranged on a portal assembly (31) for heating and melting charge material which is charged into the first and second furnaces (10/1 and 10/2), and
• first and second vessel covers (12/1, 12/2) for the first and second furnaces (10/1, 10/2),
• comprising
• each vessel cover (12/1, 12/2) is arranged together with a shaft (16/1 and 16/2 respectively) in a holding structure (17/1 and 17/2 respectively,
• each shaft (16/1, 16/2) is provided in its upper region with a loading opening (18) and a furnace gas discharge (21/1, 21/2) which is connected to the disposal conduit system (48, 49, 50), and
• the two vessel covers (12/1, 12/2) are connected together by a cover conduit (51) for the furnace waste gases.

A method of melting charge material in a smelting unit wherein said smelting unit includes a furnace vessel (11), said furnace vessel being mounted on a furnace rocking cradle (13), and a cover (12) for closing said furnace vessel, said cover having an electrode passage opening, and at least one bar electrode (28) which can be lowered into the furnace vessel (11) through said electrode passage opening in said cover (12);

• an electrode support arm (29) for gripping said at least one bar electrode;
• at least one electrode lift device (30) which can raise and lift said electrode support arm (29);
• a portal assembly (31) for carrying said at least one electrode lift device (30), said portal assembly (31) in a lowered position being releasably connected to the furnace vessel (11) and being tiltable together therewith;
• a lift post (43) of a stationary lifting/pivoting mechanism (40) for pivoting said portal assembly to a side;
• said furnace vessel in a lowered position being uncoupled from the portal assembly (31), wherein in a lowered position the portal assembly (31) lies on a support holder (33) of a vessel substructure (14) or the furnace rocking cradle (13) respectively, said method comprising the following method steps:
• charging charge material into the first melting furnace (10/1);
• controlling shut-off members (54/1, 54/2, 55) in such a way that the waste gases of the first furnace (10/1) are passed by way of the shaft (16/1) thereof to the disposal conduit system (48, 49, 50), said shut-off members (54/1, 54/2, 55) being provided for controlling the flow of gas between the two melting furnaces (10/1, 10/2) and from them to the disposal conduit system (348, 49, 50);
• heating the charge material in the first furnace (10/1) by the heating means (28) and discharging the waste gases through the shaft of said furnace (10/1);
• charging charge material into a second furnace (10/2), said second furnace arranged beside the furnace (10/1) in mirror-image relationship and said second furnace (10/2) being of the same structure and a common portal assembly (31) can be moved selectively by means of the lifting/pivoting mechanism (40) to bear on a support bolder (33/1) of the first furnace (10/1) and a support holder (33/2) of the second furnace;
• controlling the shut-off members (54/1, 54/2, 55) in such a way that the waste gases are passed from the first furnace (10/1) through the cover conduit (51) into the second furnace (10/2) and by way of the shaft (16/2) thereof and a furnace conduit (50) of the second furnace (10/2) to the central conduit (48) of the disposal conduit system (48, 49, 50);
• when the molten bath in the first furnace (10/1) is ready for tapping, controlling the shut-off members (54/1, 54/2, 55) in such a way that the waste gases of the second furnace (10/2) are passed by way of the shaft (16/2) thereof and the furnace conduit (50) thereof to the central conduit (58) of the disposal conduit system (48, 49, 50);
• heating the charge material in the second furnace (10/2) by the heating means (28) and discharging the waste gases through the shaft of said furnace (10/2);
• and
• tapping the molten bath in the first furnace (10/1).