EP3183371B1 - Hot-briquetting installation - Google Patents

Description

The invention relates to a system for hot briquetting or hot compacting, in particular directly reduced iron, with at least one press line with one or more roller presses and with at least one cooling conveyor which is arranged below the press line.

Direct reduced iron or DRI ("Direct Reduced Iron") is also known as sponge iron or sponge iron. It is produced by direct reduction of iron ore. Thereafter, a further processing of the directly reduced iron by hot briquetting or hot compacting done.

The invention preferably relates to a plant for hot briquetting, in which the directly reduced iron is compacted into briquettes in one or more roller presses designed as briquetting presses, which are then suitable for transport or storage, for example. The briquettes usually emerge in one strand from the press, so that the press is then followed by a "separating device", which separates the briquettes connected in a strand from each other.

Alternatively, however, the invention also relates to a system for hot compacting. In this case, prereduced or completely directly reduced iron is also pressed in a roller press, but not to briquettes, but there is (initially) a compaction, in which emerges from the press as an intermediate product strand of material, which is referred to as "Schülpe". This strand of material is then divided, so that the material is finally in the form of granules, which is usually processed immediately, for. B. in a further reduction process or in an immediately subsequent melting furnace.

Since the material emerging from the presses has very high temperatures, the material, in particular if it is in the form of briquettes, is first delivered to cooling conveyors, on or in which the material is flowed around by a cooling medium, for. B. a cooling liquid (eg., Water) or a cooling gas.

In order to increase the production capacity, one usually works with several roller presses for briquetting or compacting.

Such a system for hot briquetting of directly reduced iron of the type described above is z. B. from the WO 00/55379 A1 known. The known system has z. B. four roller presses or four briquetting lines connected in parallel, which are each fed from a storage bin on "Feedlegs" with feinteilchenförmigem sponge iron. Between each two Brikettierlinien or roller presses a bucket elevator and consequently a transport device for the return of fine particles is provided, which are separated with sieving below the briquetting presses from the product. For every two briquetting lines or roller presses, a cooling conveyor belt is provided for cooling and discharging the briquettes. Alternatively, a space-saving arrangement of four briquetting lines or roller presses in a rectangular arrangement will be described. From a storage bunker, four feedlegs go to the individual briquette lines. For each two briquetting together a common sieve is provided. Of the two sieves, one line in turn goes to a single cooling conveyor belt, which consequently takes up all the material.

From the DE 38 06 861 C1 One knows a transport system for hot sponge iron from a direct reduction plant to the side of the shaft furnace arranged Hot-briquetting. The hot briquetting presses are located under a briquetting feed bunker. They deliver the sponge iron in briquette form in screening, cooling and conveying systems.

In the EP 2 132 344 B1 a method is described in which directly reduced iron can be delivered via feed lines either the briquetting presses or directly to transport devices. For this purpose, a material switch is arranged above the roller presses.

From the US Pat. No. 7,622,071 B2 is a unit for compacting directly reduced iron is known in which the emerging from the roller press, compacted material is divided into two streams and transported away via two different conveyor. A similar plant will be in the US 2006/0162499 A1 described.

Furthermore, the treated DE 195 45 985 A1 a method for hot briquetting granular sponge iron with a roller press, wherein it is possible to separate fine parts below the press.

Another method for hot briquetting material is, for. B. from the US 4 533 384 A known.

Finally, that describes EP 2 641 981 A2 a plant for the production of molten iron from directly reduced iron, whereby the directly reduced iron is compacted in compacting presses and then comminuted. The material emerging from the compaction presses or from the shredders can either be fed to a smelting furnace via a first conveyor or stored in storage containers via a second conveyor. Therefore, switches are arranged under the crushers that the material can be dispensed either on the first conveyor to the melting furnace or on the second conveyor to the storage container.

In such systems for hot briquetting or hot compacting directly reduced iron is always the need to optimize the capacity. In addition, safety considerations in the design of the system in the foreground. When processing hot material from directly reduced iron, for example, a reliable removal of the briquettes with simultaneous cooling must be ensured, even if parts of the system fail. - This is where the invention starts.

The invention has for its object to provide a system for hot briquetting or hot compacting, especially of directly reduced iron, which is characterized by high reliability. In addition, the system should be characterized by high efficiency.

To solve this problem, the invention teaches a system for hot briquetting or hot compacting, in particular directly reduced iron, with the features of claim 1.

According to the invention, therefore, two cooling conveyors are provided, which are each designed so that they can individually absorb and discharge the material from the roll presses. Thus, in normal operation, it is possible to discharge the material of the presses together via both cooling conveyors. In case of failure, z. B. in case of failure of a cooling conveyor, with the aid of the switches, it is possible to remove the (entire) material via the other, ready-to-operate cooling conveyor. Alternatively, it is also possible to work with only one cooling conveyor in normal operation, and the other cooling conveyor is then used only if the first cooling conveyor fails. Anyway, through the design of the system with several cooling conveyors and corresponding switches improves the reliability of the system.

The presses are arranged in several press rows, namely a first press line and a second press line, the first cooling conveyor below the first press line and the second cooling conveyor below the second press line is arranged and wherein the switches are adjustable so that the material of the roll presses each of the first press line and the second press line can be selectively dispensed onto the first cooling conveyor or the second cooling conveyor.

Preferably, in this case, the first press line several on a line, z. B. straight line one behind the other arranged first roller presses and the second press line has several on a line, z. B. straight line one behind the other arranged second roller presses, wherein in each case two paired juxtaposed roller presses from the first press line on the one hand and the second press line on the other hand, a switch is associated.

The invention is based on the generally known knowledge that the capacity of such a system by the use of a variety of roller presses, z. B. at least four roll presses, preferably at least six roller presses, can increase. Preferably, the roll presses are arranged in at least two rows of presses. Compared to the possible arrangement of the presses in a single press line, this arrangement in two rows of presses has the advantage that the feed presses arranged above the roll presses can be arranged at a steeper angle with the same number of presses than with an arrangement of the same number of presses in a single press line As the angle of the feedlegs increases The lying at the ends of the press line roller presses is always flatter. However, this is not acceptable for reasons of operational safety, because the angle of the Feedlegs against the vertical should be in practice a maximum of about 30 ° to ensure proper material supply of directly reduced iron to the roller presses. It is therefore preferred that an arrangement is realized in two rows, in particular when a total of more than three presses are provided.

According to the invention, it is proposed in such an embodiment to associate the two rows of presses with a cooling conveyor so that in normal operation the material of the first row of presses is delivered to one cooling conveyor (eg the first cooling conveyor) and the second press line to the other cooling conveyor (eg the second cooling conveyor) is dispensed. However, the switches provided according to the invention now permit variable operation, in particular in the event of a fault. If one of the cooling conveyors fails, it is possible with the aid of the switches to dispense both the material of the first press line and the material of the second press line onto only one of the cooling conveyors, that is to say either the first cooling conveyor or the second cooling conveyor. In order to increase the reliability, it is preferably provided that the two cooling conveyors are each designed so that they can individually record and transport all the material of the system individually. The cooling conveyors are therefore adapted to the total plant capacity. It is expedient if each cooling conveyor can individually record each more than the material of a single press line. Thus, a total of even with failure of a cooling conveyor, the production can be continued with two rows of presses, since the then still in operation cooling conveyor is dimensioned so that the entire material can be conveyed away.

It is advantageous if the press row or each press row has at least two roll presses, preferably in each case three roll presses. It is in several rows of presses also in the context of the invention that the press rows have a different number of roller presses, z. B. the first press line three roll presses and the second press line four roll presses, it is advantageous if two roll presses from each of the first press line and the second press line are arranged in pairs next to each other.

According to a further proposal of the invention it is provided that below the roller presses sieves for separating fines ("hot fines") are arranged, these fines can be recycled with one or more transport devices to the briquette presses. The points are again arranged under the sieves. Transport devices are basically known, they can be designed as so-called "bucket elevators". For this purpose, the invention preferably proposes that these transport devices, for. B. bucket elevators, are arranged between the press rows. Thus, it is expedient if between each pair of juxtaposed roller presses in each case at least one transport device, for. B. a bucket elevator, is arranged.

According to the invention, the arrangement is characterized by a high degree of security, since a material cooling is ensured even in case of failure of a cooling conveyor. On an uneconomical emergency emptying, which would be conceivable in principle, can therefore be waived.

In a preferred development, a plant is created which is characterized by its compact construction and high production capacity and availability. The system is characterized among other things by a small tower height because of the arrangement of the presses in two rows of presses with relatively short Feedlegs can be worked, but nevertheless arranged sufficiently steep. There is also sufficient space between the individual machines for escape routes and sufficient space to open the roller presses for a roll change or to carry out other maintenance work. Another advantage is the fact that the individual roller presses can each be constructed identically and can also be arranged in an identical orientation in the rows of presses. There are no special adjustments and no "mutual orientation" of adjacent presses required so that handling and maintenance are further simplified. The availability of the system is also improved by the fact that not only the presses but also the cooling are redundant.

Fig. 1

eine erfindungsgemäße Anlage zum Heißbrikettieren von direkt reduziertem Eisen in einer vereinfachten Draufsicht,

Fig. 2

den Gegenstand nach Fig. 1 in einer vereinfachten Ansicht aus Richtung des Pfeils A und

Fig. 3

den Gegenstand nach Fig. 1 in einer vereinfachten Ansicht aus Richtung des Pfeils B.

Fig. 4

eine abgewandelte Ausführungsform der Erfindung in vereinfachter Darstellung.

In the following the invention will be explained in more detail with reference to a drawing showing only one exemplary embodiment. Show it

Fig. 1

a plant according to the invention for hot briquetting of directly reduced iron in a simplified plan view,

Fig. 2

the object after Fig. 1 in a simplified view from the direction of arrow A and

Fig. 3

the object after Fig. 1 in a simplified view from the direction of arrow B.

Fig. 4

a modified embodiment of the invention in a simplified representation.

In the figures - schematically simplified - a system for hot briquetting of directly reduced iron is shown. The directly reduced iron is z. B. made of pellets and / or lump, with a direct reduction is carried out with gas. Details of the production of the directly reduced iron are not shown in the figures. The directly reduced iron is supplied from the direction of the arrow X.

The plant shown in the figures for hot briquetting has a first press line 1 with a plurality of first roll presses 2 and a second press line 3 with a plurality of roll presses 4. The directly reduced iron is supplied from the direction of the arrow X via supply lines 5, which are also referred to as "feedlegs". A comparative analysis of the Fig. 2 and 3 shows that a Feedleg 5 is provided for each roller press. In the illustrated embodiment, the first press line 1 on three consecutively arranged roller presses 2 and the second press line 3 also has three successively arranged roller presses 4. In roller presses 2, 4 the directly reduced iron is pressed into briquettes. There is the possibility that from the roller presses 2, 4 emerge directly individual briquettes. However, it is usual for a briquette strand to emerge from the roll presses 2, 4 first, and for the briquettes to be singulated below the roll presses with a suitable shredder 12. Then, the material (in the exemplary embodiment briquettes) passes through a plurality of material lines 6 to cooling conveyors 7, 8, which are arranged below the roll presses 2, 4. In the illustrated embodiment according to Fig. 1 to 3 the first cooling conveyor 7 is arranged below the first press line 1, while the second cooling conveyor 8 is arranged below the second press line 3. According to the material lines 6 are equipped with switches 9. These switches 9 are designed and integrated into the material lines 6 such that the briquettes from the first press line 1 optionally on the first cooling conveyor 7 or on the second cooling conveyor 8 can be discharged. In the same way, the briquettes from the second press line 3 can be dispensed selectively onto the second cooling conveyor 8 or onto the first cooling conveyor 7.

In normal operation, the plant is operated so that the material from the roller presses 2 of the first press line 1 on a cooling conveyor, the first cooling conveyor 7, is discharged, while the material from the roller presses 4 of the second press line 3 on the other cooling conveyor, the second cooling conveyor 8, is delivered.

Should one of the cooling conveyors 7, 8 fail, then the switches 9 can be switched over in such a way that then all the material from both the roller presses 2 of the first press line 1 and from the roller presses 4 of the second press line 3 to only one cooling conveyor, z. B. the first cooling conveyor 7 or alternatively the second cooling conveyor 8 is discharged, depending on which conveyor is ready for use. The inventive system is thus characterized by a high reliability, because even if a cooling conveyor is ensured that the hot material is properly transported away, without a plant stop or emergency emptying would be required.

In the Fig. 1 to 3 an embodiment is shown in which two roller presses 2, 4, a common switch 9 is assigned. The switch is designed in the embodiment as X-turnout (see. Fig. 3 ). Alternatively, it is within the scope of the invention that more than two roller presses can be assigned a common switch. So z. B. two roller press pairs and consequently a total of four roller presses a common Be associated with switch. This embodiment is not shown in the figures.

Incidentally, it can be seen in the figures that screens 10 for separating fine parts can be arranged below the roller presses 2, 4. These fines can then be returned back to the roller presses with transport devices 11. The switches 9 are arranged below the wires 10. The sieves 10 are - as in Fig. 3 recognizable - inserted into the material lines 6. The material thus passes in each case from a roller press 2, 4 via the separating device 12 in a first part of the material line 6 and from there to the wire 10 and then the second part of the material line 6. This is followed by the switch 9 and in turn a third part the material line 6 at.

The transport devices 11 are formed in the embodiment as bucket elevators. It can be seen in the figures that these bucket elevators 11 are arranged between the press rows 1, 3. Each two roller presses is associated with a common transport device 11, so that each transport device 11 is positioned between two adjacent roller presses.

In Fig. 4 a modified embodiment of the invention is shown, in which the roller presses 2 are arranged only in a single press line 1. Below this single press line 1, two cooling conveyors 7, 8 are arranged. As in the embodiment according to Fig. 1 to 3 The material from the roller presses 2 via material lines 6 on the cooling conveyor 7, 8. In the material line 6 turnouts 9 are integrated, so that the material can be discharged from the roll presses 2 selectively on the first cooling conveyor 7 or on the second cooling conveyor 8 , Also This embodiment is therefore characterized by an increased level of reliability, since the material can be absorbed by the other cooling conveyor in case of failure of a cooling conveyor. In this embodiment, the switches 9 are formed as Y-switches. Details are not shown.

Incidentally, the invention optionally also includes embodiments with more than two rows of presses and / or more than two cooling conveyors. So z. B. three (or more) press rows and including three (or more) cooling conveyor may be provided. Such an embodiment is not shown in the figures.

Claims (8)

1. An installation for the hot briquetting or hot compacting, in particular of directly reduced iron,
   with at least one first press series (1) with one or more roller presses (2) and at least one second press series (3) with one or more second roller presses (4),
   with at least one first cooling conveyor (7) and one second cooling conveyor (8) wherein the first cooling conveyor (7) is arranged under the first press series (1) and the second cooling conveyor (8) is arranged under the second press series (3), and
   with several material pipelines (6) allocated to the individual roller presses (2, 4) via which the briquetted or compacted material emerging from the roller presses (2, 4) is transferred to the cooling conveyors (7 ,8),
   wherein the material pipelines (6) are equipped with several deflectors (9), wherein the deflectors (9) are adjustable in such a way that the material from the roller presses (2, 4) of the first press series (1) and the second press series (3) is in each case optionally transferred to the first cooling conveyor (7) or to the second cooling conveyor (8).
2. The installation according to claim 1, wherein the first press series (1) comprises several first roller presses (2) arranged one after the other in a line, e.g. a straight line, and the second press series (3) comprises several second roller presses (4) arranged one after the other in a line, e.g. a straight line.
3. The installation according to any one of claims 1 to 2, wherein a joint deflector is allocated to two roller presses arranged next to each other in pairs, one roller press (2) from the first press series (1) on the hand and one roller press (4) from the second press series (3) on the other hand.
4. The installation according to any one of claims 1 to 3, wherein a joint deflector is allocated to more than two roller presses, e.g. two roller press pairs arranged one after the other composed of two roller presses arranged one after the other.
5. The installation according to any one of claims 2 to 4, wherein the cooling conveyors (7, 8) are each designed and adapted to the capacity of the roller presses in such a way that in operation they can each take up and transport away more than the material of only one of the press series.
6. The installation according to any one of claims 1 to 5, wherein underneath the roller presses (2, 4) sieves (10) are arranged for separating fine particles, said fine particles being returnable with transporting devices (11), e.g. bucket conveyors, to the roller presses (2, 4), wherein the deflectors are preferably arranged underneath the sieves (10).
7. The installation according to claim 6, wherein in each case at least one transporting device (11) is allocated to two roller presses (2, 4) arranged next to each other in pairs.
8. The installation according to claim 7, wherein the transport device (11) is arranged between the roller presses (2, 4) arranged next to each other in pairs and/or between the cooling conveyors (7, 8).

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