DE2312243C2 - Device for feeding solid batches into electrically heated melting furnaces - Google Patents

Description

30th

The invention relates to a device for the selective, automatic and controllable supply of Solids as a feed for electrically heated melting furnaces.

An electric furnace for the extraction of z. B. Pig iron, iron alloys and carbide is with equipped with a number of hoppers, which are arranged above the furnace and the raw materials to the Allocate oven. The filling funnels have open chutes at the bottom; forms below each outlet opening a pile of feed material. These piles lie on the feeder, and to the extent that they do When the load in the furnace drops, the discharge from the hopper takes place automatically and continuously.

Typically, the hoppers contain a mixture of feed components, e.g. B. Ore, reducing agent, Flux and other supplements.

The hopper reservoir must hold enough material to prevent the Feed, e.g. B. as a result of bridging, collapse and tapping, to be able to compensate. as well it must be possible to bridge downtimes in the feed system. When a hopper is complete emptying, the flames from the furnace can reach the loaders and damage them. Because of the required supply reserve in the hopper, it now takes a relatively long time until the material fed at the top of the hopper enters the furnace. This delay or "dead time" can be 4 to 8 hours and is very disadvantageous, if it is necessary, the composition of the charge mixture to correct or change.

The feed mixture in the hopper is generally composed so that under the desired product is created under certain process conditions. However, it can from time to time it may be necessary to make corrections by changing the mixing ratios or by adding surcharges, z. B. it may be necessary to increase the conductivity of the charge by increasing the supply of coke or the conductivity due to a higher proportion of flux to reduce. The electrical conductivity is known to determine the position of the electrodes and the electrical conditions of furnace operation.

Up until now, correction material has been fed in by hand or by means of separate feed devices directly on the top of the oven and not through the hopper. This direct feed has the advantage a quick effect without delay due to the passage through the hopper. This method however, it has several disadvantages. It is not always possible to do this, especially with covered ovens Bringing correction material to where it is needed. It is also disadvantageous that in this way the correction material is concentrated and not distributed in the feed.

It is the object of the invention to selectively, automatically, solid charging and charging components and controllable by means of a conventional hopper.

This object is achieved according to the invention by dividing a filling funnel into two rooms, namely a storage space and a through shaft. For this purpose, there is a vertical shaft in the hopper Dividing wall arranged, which ends above the bottom of the hopper. The pantry can therefore with the Charging can be filled while charging components are fed through the through shaft will.

If the through shaft is arranged just above the opening of the hopper and the The opening area of the through shaft corresponds practically completely to the opening area of the filling funnel the material in the through-shaft can be emptied before the material in the storage space will. It is therefore not necessary to provide flaps or other mechanical locking devices. As long as there is material in the through shaft, it is abandoned, and so is the through shaft is emptied before material runs out of the hopper's storage space.

The amount of material that is in the manhole at any one time determines that Dead time in the hopper, d. H. the time that elapses from the introduction of new material to the access shaft until the introduction of this material into the furnace. It is desirable for the regulation technique that this dead time is as short as possible. The through shaft is therefore small in relation to the storage room Volume. The type of material supply to the hopper is important for the dimensioning of the hopper determining. If - as is usually the case - the hopper is filled in batches, then the There should be space for at least one full batch through shaft.

An exemplary embodiment of the invention is shown schematically in the drawings.

The filling funnel 1 has an outlet pipe 2 and a partition wall 3 which divides the filling funnel into the through shaft 4 and the storage space 5. The lower The end of the dividing wall 3 is located above the funnel bottom, so that a passage from the storage space 5 to the outlet pipe 2 is established. The lower part of the storage space 5 is beveled towards the outlet pipe or conical in the case of a round design of the filling funnel.

When the opening area of the manhole 4 is equal to the opening area of the discharge pipe 2, the passage shaft 4 is completely emptied before the material flows out of the storage space 5 The distance between the lower end of the dividing wall 3 and the funnel bottom is determined empirically accordingly the piece size and the sliding angle of the filler material.

The invention can be used in combination with the feed system and with for the purpose of regulation in the Hopper provided level indicators can be used in various ways. Two main methods are shown in FIGS. 2 and 3 shown.

In the embodiment according to FIG. 2, practically the entire batch goes through the through shaft and the material supply from the conveyor 6 is indicated by a filling level indicator arranged in the through shaft 4 7 controlled. The refilling takes place via the storage space 5, from which the material on the Partition wall 3 overflows into the passage shaft as soon as the storage space is full. With the exception a small outflow, so to speak a leak, which prevents sintering and bridging is advantageous, the filling of the storage space 5 remains at rest until the passage shaft 4 is complete is emptied When the through shaft is emptied, which, if correctly dimensioned, only occurs when it collapses the furnace filling or malfunctions in the feed system above the filling hopper can occur, the Feeding into the furnace automatically from the storage room 5. With this mode of operation you can Corrections to the feed composition are carried out in the main feed itself, namely with quick effect in the oven.

In the embodiment according to FIG. 3, the through-shaft 4 is normally empty, and the The main load runs through the storage room 5. The material is fed through the in the storage room 5 arranged level indicator 8 controlled. If correction surcharges are required, these supplied via the conveyor 9; the correction material quickly reaches the through shaft 4 Outlet pipe 2 and the oven. The desired effect is thus achieved with an extremely short dead time.

For this purpose 3 sheets of drawings

Claims (3)

1 claims: 1. Device for selective, automatic and controllable feeding of solid batches and such charging components in electrically heated melting furnaces, thereby identified I η et that the hopper (1) has an inner dividing wall (3) that extends down to a level above the outlet pipe (2) extends and the filling funnel into two rooms, divides the through shaft (4) and the storage space (5), the outlet opening for the through shaft just above the outlet pipe (2) of the Filling funnel is arranged and has an opening area which is practically completely the opening area of the outlet pipe (2) corresponds 2. Apparatus according to claim 1, characterized in that a conveyor (6) for charging is arranged above the storage space (5), so that when the storage space (5) is full, the charging via the the upper edge of the dividing wall (3) overflows into the through shaft (4) 3. Device according to claim 1, characterized in that that the conveyor (6) for normal charging over the storage space (5) and a Conveyor (9) for charging components is arranged above the through shaft (4).