EP3081655A1 - Barrier for reducing the dust emissions for a cooler for cooling warm bulk material - Google Patents

Abstract

The invention relates to a cooler (1) for cooling hot bulk material (17) which has a grate surface (16) for receiving the hot bulk material (17) to be treated, preferably iron ore sinter. The task is to reduce the dust emissions and at the same time to allow maintenance of the radiator (1). The object is achieved by a device which, in addition to the already existing covers - which are located in the region of the feed point (2) and the removal point (3) - provides an additional limitation which prevents the removal of dust particles of more than 150 .mu.m. The boundary consists of a fixed first wall (12) and a fixed second wall (11) and preferably extends over a partial section over the entire area of the uncovered grate surface (16). Furthermore, a support structure (18) is provided on which the first wall (11) and the second wall (12) are attached.

Description

Field of engineering

The present invention relates to the field of metallurgical plants, specifically the iron industry for cooling hot bulk material.

• eine Rostfläche zur Aufnahme des zu behandelnden heißen Schüttguts,
• eine erste Kühlerwand und eine zweite Kühlerwand welche die Rostfläche rechts und links begrenzen,
• eine Aufgabestelle für das heiße Schüttgut,
• einen ersten Bereich, der zwischen 20% und 30% der Rostfläche umfasst, wobei der erste Bereich die Aufgabestelle beinhaltet und der erste Bereich eine ortsfeste erste Abdeckung aufweist
• einen zweiten Bereich der nach oben offen ist und zwischen dem ersten Bereich und einem dritten Bereich liegt
• eine Entnahmestelle für das gekühlte Schüttgut
• den dritten Bereich, der sich über zumindest 10% bis zu 20% der Rostfläche erstreckt, wobei der dritte Bereich die Entnahmestelle beinhaltet und eine ortsfeste dritte Abdeckung aufweist.

The invention relates to a cooler for cooling hot bulk material comprising:

• a grate surface for receiving the hot bulk material to be treated,
• a first cooler wall and a second cooler wall which delimit the grate area on the right and on the left,
• a feeding point for the hot bulk material,
• a first region comprising between 20% and 30% of the grate surface, the first region including the feed point and the first region having a stationary first cover
• a second area which is open at the top and lies between the first area and a third area
• a removal point for the cooled bulk material
• the third region, which extends over at least 10% to as much as 20% of the grate surface, the third region including the extraction site and having a stationary third cover.

State of the art

It is known to carry out the cooling of bulk material on coolers which continuously convey bulk material. The continuous promotion can be done straight or in a circle. Such a machine - in this case an annular machine - is in EP0127215B1 shown. These machines have an annular grate surface, at a feed point is the Rust surface loaded with hot bulk material and during a revolution - blown through below the grate arranged fan boxes - a cooling gas, in particular cooling air. At a sampling point, which is located directly next to the Aufgabestelle, the cooled bulk material is discharged again. When operating such a machine very large dust emissions occur. Therefore, covers and dedusting facilities are provided in the area of the task and removal point. In this area occur the largest dust emissions, but also in the remaining area of the annular machines occur through the blowing of the cooling air dust emissions, which increase the dust content in the air. Currently, only about 30-50% of the annular grate surface is often covered. A gastight cover of the entire grate surface - as in EP0127215B1 is shown - is usually therefore not carried out, since it would suck the entire amount of gas and dedusted. This amount of gas would be 1.5-2 times the size of the process gas. This would lead to large investment costs - due to large blower and filter sizes - for dedusting. Another disadvantage of this design is that it is very expensive to service the annular machine. Due to the gas-tight cover, it is very expensive to perform maintenance. The disassembly and subsequent assembly of this gas-tight cover is very expensive. The tightness of the cover must be restored each time, so as not to suck in unwanted gases or solids from the outside, which would additionally increase the amount of gas to be dedusted.

Summary of the invention

The object of the present invention is to provide a device which on the one hand reduces the dust emissions and on the other hand enables maintenance measures on the radiator easily and in a short time.

This object is achieved by the radiator mentioned above in that the second region has a boundary consisting of a stationary first wall and a stationary second wall, and this boundary extends to at least a portion of the second area, preferably over the entire second area, wherein the first wall and the second wall are suspended from a support structure, and the first wall rests on the first radiator wall or from it is separated by a gap, and the second wall rests on the second radiator wall or is separated from it by a gap.

The resting on the first radiator wall or separated by a gap first wall, and resting on the second radiator wall or separated by a gap second wall prevent transport of - located on the grate surface - dust by the cooling gas or by external wind influence. Under rest or separated by a gap in this context means that the movement of the radiator is not hindered by excessive friction between the walls and a possible gap should be made as small as possible - to prevent the escape of dust particles. Due to the exit velocity of the cooling gas from the bulk material located on the grate surface, particles are carried along by the cooling gas. Due to the dedusting at the feed point, a large part of the dust particles - which are smaller than 150 μm in size - are removed. By the cooler according to the invention was surprisingly found that dust particles are larger than 150μm and which ascend through the cooling air for the most part again settle on the grate surface or on the bulk material thereon. The first wall and the second wall prevent the entrained particles are not removed by external wind influence or the cooling gas. For example, external wind influence is a crosswind that acts on the radiator transversely to the direction of movement. In the case of an annular cooler, it can also act partially in the direction of movement and - due to the round shape of the cooler - remove the particles beyond the surface of the grate. The height of the side walls depends on the exit velocity of the cooling gas from the bulk material.

At a discharge velocity of the cooling gas from the bulk material of 2 m / s results in a height of the boundary of 1.8 m. The height of the boundary is the height which is measured from the upper edge of the bulk material to the upper edge of the first wall or second wall - preferably the first wall and the second wall are the same height - is measured.

The first wall and the second wall are arranged stationary and the cooler is designed to be movable. Movable means that it is a continuous promotion that can take place in a circle or even straight. On the one hand to ensure the best possible seal between the first radiator wall and the second radiator wall and the first wall and the second wall, and on the other hand, not to complicate the mobility unnecessarily by large frictional forces, a support structure is provided at the first wall and the second wall are hung up. This support structure is designed so that a rapid disassembly of the boundary can take place, it does not need to be restored as shown in the prior art, the gas-tightness. The limitation greatly reduces the amount of diffusely emitted dust.

The boundary should extend over a partial area, preferably over the entire second area. In order to allow maintenance on the cooler without dismantling the boundary, the sum total is covered by the first cover, the third cover and the boundary between 80% and 95% of the grate area. To achieve the greatest effect for the reduction of dust emissions, the first cover, third cover and the boundary encompass the entire grate area.

An advantageous embodiment of the annular cooler is that the boundary of a height which is measured between the upper edge of the bulk material and upper edge of the first wall or second wall of at least 1m, preferably 1.5m, more preferably 2.0m very particularly preferably 2.5m having.

The height between the top edge of the bulk material and the top edge of the first wall or second wall affects the result of reducing dust emissions. Would the top edge the first wall or second wall are only a few decimeters above the bulk material, the effect of reducing the dust emission would be very low. Therefore, the boundary should have a minimum height of 1m. This sets the desired effect that the dust particles settle back on the grate surface. At a distance of more than 2.5 m, no noticeably higher reduction of dust emissions is noticeable.

A variant provides that
the boundary additionally has a perforated plate located between the first wall and the second wall.

The perforated plate is disposed between the first wall and the second wall so as to face the grate surface, preferably substantially parallel to the grate surface. By essentially parallel, angular deviations of up to ± 10 ° are meant.

The perforated plate further improves the reduction of dust emissions. On the one hand, the perforated plate ensures that dust particles - which would be carried over the boundary - are retained and, on the other hand, that the existing cooling gas can emerge uniformly over the entire grate surface. Under perforated plate is a plate understood - for example, from a steel sheet - which holes, other cutouts or openings have that allow the cooling gas can flow through. Another example of a perforated plate is a grate.

The perforated plate lies between the first wall and the second wall.

A further advantageous embodiment of the cooler is that the boundary consists of individual segments.

The radiator must be serviced at regular intervals. In this case, individual components of the radiator are changed. To make this easy and in a short time, the Boundary of several segments, which are mounted by an easily detachable connection - such as a screw or bolt connection. The individual segments each consist of a first wall and second wall corresponding to the segment size. A segment may additionally have a perforated plate. The respective segments of the boundary can either be lifted off as a whole after releasing the connection between the segment and the supporting structure, or the first wall and / or second wall and / or the perforated plate of the segment are removed. The segments can have different sizes. One possible variant is that the boundary consists of only two segments, a large segment that is removed only in exceptional cases and a smaller one which is removed for maintenance purposes. To minimize manufacturing effort, a preferred solution is to make all segments the same size.

One embodiment provides that a temperature-resistant seal is attached to the transition from the first cooler wall to the first wall and the transition from the second cooler wall to the second wall.

Such a temperature-resistant seal may for example consist of a fabric or be designed as a brush seal. Under temperature resistance is understood in this context, a temperature up to 600 ° C. These seals can be on the outside of the second wall and first wall - that is not the side facing the hot bulk material - and / or the inside - the bulk material facing side - be appropriate.

A further advantageous embodiment is that the perforated plate perforations of up to 70%, preferably up to 60%, most preferably of up to 50% of the total area - the perforated plate - has. It has been found that perforations in a range of 50% to 70% provide the best results in terms of reducing dust emissions and refrigerant gas leakage.

As an advantageous embodiment, it has been found that the perforated plate is made of expanded metal. An expanded metal has excellent properties in terms of openings, strength and weight. On the one hand, the dust emissions are reduced to a minimum and on the other hand, the cooling gas can emerge uniformly over the entire surface. The lower weight has a positive effect on the supporting structure - as it can be designed for lower loads.

A preferred embodiment provides that the hot bulk material is iron ore sinter or manganese ore sinter.

The coolers according to the invention are frequently used for cooling iron ore sinter and manganese ore sinter.

An advantageous embodiment is that the cooler is designed as an annular radiator. An annular radiator can be made more compact to hold the same amount of bulk material. Another great advantage is that in an annular cooler almost the entire grate surface is loaded with bulk material and this can thus be cooled. For a straight cooler, the grate area moving from the point of removal to the point of loading is not loaded. Thus, only about half of the grate surface can always be used. An annular radiator requires only half the grate area compared to a straight radiator - bulk material to be cooled for the same amount.

In the case of an annular cooler, the limitation is particularly advantageous since the removal of the particles by wind influence can always occur from all directions. Through the round embodiment, the problem of shipping by wind influence is always given. There is no clear wind direction that is particularly critical or particularly uncritical.

Another embodiment of the annular radiator provides that the individual segments have an angle of at least 10 ° and a maximum of 20 °. The size is chosen so that maintenance of the annular radiator can be done and the limitation can be removed with reasonable effort and in a short time.

Brief description of the drawings

• Fig. 1 eine schematische Darstellung eines Ringförmigen Kühlers nach dem Stand der Technik
• Fig. 2 eine schematische Darstellung eines geraden Kühlers nach dem Stand der Technik
• Fig. 3 eine schematische Darstellung eines erfindungsgemäßen Kühlers
• Fig. 4 eine vorteilhafte Ausführungsvariante eines erfindungsgemäßen Kühlers
• Fig. 5 eine vorteilhafte Ausführungsvariante eines erfindungsgemäßen Ringförmigen Kühlers
• Fig. 6 eine schematische Darstellung eines erfindungsgemäßen Geraden Kühlers

In the following, the present invention will be described by way of example with reference to schematic figures, which show the following:

• Fig. 1 a schematic representation of an annular radiator according to the prior art
• Fig. 2 a schematic representation of a straight cooler according to the prior art
• Fig. 3 a schematic representation of a cooler according to the invention
• Fig. 4 an advantageous embodiment of a cooler according to the invention
• Fig. 5 an advantageous embodiment of an annular radiator according to the invention
• Fig. 6 a schematic representation of a straight line radiator according to the invention

Description of the embodiments

Fig. 1 shows a plan view of an annular radiator 1. It is the Aufgabestelle 2 - which in the first area. 4 is - as well as the cover located above the first area 4 7 shown. The first region 4 comprises a region which is characterized by the angle α ₁ . The first region 4 is followed by the second region 5 in the direction of rotation, which is shown by the arrow. The second region 5 has no cover. The annular radiator 1 has a grate surface 16 - which is bounded by a first radiator wall 10 and a second radiator wall 9 - which can accommodate hot bulk material. The size of the second region 5 is represented by the angle α ₂ .

A third area 6 lies between the other two areas 4 and 5, and in this third area 6 there is also the discharge point 3 and a third cover 8. The size of the third area 6 is represented by the angle α ₃ . In an annular radiator, the first radiator wall 10 corresponds to a radiator inner wall and the second radiator wall 9 corresponds to a radiator outer wall.

Fig. 2 shows a side view of a straight line radiator 1. It is the Aufgabestelle 2 - which is located in the first region 4 - and the cover located above the first region 4 7 is shown. The second region 5 follows the first region 4 in the direction of the movement direction, which is shown by the arrow. The second region 5 has no cover. The straight radiator 1 has a grate surface 16 - which is bounded by a first radiator wall 10 and a second radiator wall 9 - which can accommodate hot bulk material. A third area 6 then follows the second area 5 and in this third area 6 there is also the discharge point 3 and a third cover 8.

In Fig. 3 An embodiment according to the invention of the apparatus for reducing the dust emissions in an annular radiator is shown.

The hot bulk material 17 is located on the grate surface 16 which is bounded by the second cooler wall 9 and the first cooler wall 10. On the second radiator wall 9 is located a second wall 11 and on the first radiator wall 10, a first wall 12. Through the grate surface 16 cooling air 15 is blown by means of a fan box 14 through the hot bulk material 17. On the surface of the bulk material 17, the cooling air 15a exits, whereby dust particles are carried. The first wall 12 and the second wall 11 are fixed to a support structure 18. This is done so that the rotational movement of the annular radiator 1 by the weight of the first wall 12 and second wall 11 is not difficult and disassembly can be done quickly. The disassembly of the second wall 11 and the first wall 12 is required for the maintenance of the annular radiator.

In Fig. 4 an advantageous embodiment of an annular radiator according to the invention is shown. This variant is different from Fig. 2 in that a perforated plate 19 is installed between the second wall 11 and the first wall 12. Furthermore, a temperature-resistant seal 13, 13 a at the transition between the first radiator wall 10 and the first wall 12 and between the second radiator wall 9 and second wall 11 is arranged. This seal 13, 13a will prevent dust particles from moving away from the radiator via this path. The reference numbers not mentioned here were already in the FIG. 3 described.

In Fig. 5 a further advantageous embodiment of the annular radiator according to the invention is shown. It is a plan view in which it can be seen that the first wall 12a and the second wall 11a consist of individual segments. The size of the individual segments are represented by the angle β - in this embodiment, all segments are the same size. These segments of the second wall 11a and the first wall 12a are each suspended on the support structure 18 - the support structure is shown in this figure only for one segment. Each segment consists of a first wall 12a, second wall 11a and, if present, a perforated plate. The perforated plate has not been shown in this figure for reasons of clarity. The reference numbers not mentioned here were already in the FIG. 1 described.

Fig. 6 shows a side view of an advantageous embodiment of a straight cooler according to the invention 1. Here, the first wall 12a-c on the first radiator wall 10 and the second wall 11a-c on the second radiator wall 9 is arranged. By means of the support structure 18, the first wall 12a-c and the second wall 11a-c suspended, also a perforated plate 19a-c is also attached. In this illustration, the segmentation of the first wall 12a, 12b and 12c, the second wall 11a, 11b and 11c and the perforated plate 19a, 19b and 19c can be seen. Thus, it is always possible to remove those parts - the three segments - which are currently needed to carry out maintenance measures.

The reference numbers not mentioned here were already in the FIG. 2 described.

While the invention has been further illustrated and described in detail by the preferred embodiments, the invention is not limited by the disclosed examples, and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

LIST OF REFERENCE NUMBERS

1

cooler

2

application site

3

sampling point

4

first area

5

second area

6

third area

7

first cover

8th

third cover

9

second cooler wall

10

first cooler wall

11, 11a-c

second wall

12, 12a-c

first wall

13, 13a

poetry

14

blower box

15

Cooling gas entering the grate area

15a

Cooling gas at the exit from the bulk material

16

grate area

17

bulk

18

supporting structure

19, 19a-c

perforated plate

α ₁

Angle first area

α ₂

Angle second area

α ₃

Angle third area

β

Size of the segments

Claims (10)

A cooler for cooling hot bulk material (17) comprising: a grate surface (16) for receiving the hot bulk material (17) to be treated, a first radiator wall (10) and a second radiator wall (9) which delimit the grate surface (16) on the right and left, a feed point (2) for the hot bulk material (17), - A first region (4) comprising between 20% and 30% of the grate surface (16), wherein the first region (4) includes the feed point (2) and the first region (4) has a fixed first cover (7) - A second region (5) which is open at the top and between the first region (4) and a third region (6) - An extraction point (3) for the cooled bulk material (17) the third region (6), which extends over at least 10% up to 20% of the grate surface (16), the third region (6) containing the removal point (3) and having a stationary third cover (8), characterized in that the second region (5) has a boundary consisting of a stationary first wall (12) and a stationary second wall (11), and this boundary extends over at least a portion of the second region (5), preferably over extending the entire second region (5), wherein the first wall (12) and the second wall (11) are suspended from a support structure (18), and the first wall (12) rests on or from the first radiator wall (10) is separated by a gap, and the second wall (11) rests on the second radiator wall (9) or is separated from it by a gap. Cooler according to claim 1, characterized in that the boundary is a height which is measured between the upper edge of the bulk material (17) and upper edge of the first wall (12) or second wall (11) of at least 1m, preferably 1.5m, particularly preferred 2.0m very particularly preferably 2.5m. Radiator according to claim 1 or 2, characterized in that the boundary additionally comprises a perforated plate (19) located between the first wall (12) and the second wall (11). Radiator according to one of the preceding claims, characterized in that the boundary consists of individual segments. Radiator according to claim 1, characterized in that a temperature-resistant seal (13) is mounted on the transition from the first radiator wall (10) to the first wall (12) and at the transition from the second radiator wall (9) to the second wall (11). Cooler according to claim 3, characterized in that the perforated plate (19) has perforations of up to 70%, preferably up to 60%, most preferably up to 50% of the total area. Cooler according to claim 1, characterized in that the perforated plate (19) is made of expanded metal. Cooler according to claim 1, characterized in that the hot bulk material (17) is iron ore sinter or manganese ore sinter. Radiator according to one of the preceding claims,
characterized in that the cooler (1) is designed as an annular radiator. Radiator according to claim 9, characterized in that
the individual segments of the annular radiator (1) have an angle of at least 10 ° and a maximum of 20 °.

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