WO2012032073A1 - Machine for the thermal treatment of solids - Google Patents

Abstract

The invention relates to an annular machine for the thermal treatment of solids, in particular for producing pellets from iron ore, comprising a plurality of gas-permeable gratings (1a, 1b) which are supported by a support structure (2a-2c, 3, 4) revolving on wheels and which are arranged such that they can be lowered about a tipping axis at an unloading point, wherein the support structure has radially arranged spokes (2a-2c) which are connected together by means of an inner support ring (3). In order to prevent deformation of the spokes, it is provided that the support structure also has an outer support ring (4), by means of which the spokes (2a-2c) are connected together, wherein the spokes or any covers of the spokes cannot project upwards beyond the plane of the grating (1a, 1b).

Description

description

Machine for the thermal treatment of solids

FIELD OF THE INVENTION

The invention relates to an annular machine for

thermal treatment of solids, in particular for the production of pellets from iron ore, comprising a plurality of gas-permeable grids, which are supported by a revolving on wheels supporting structure and at a

Unloading are arranged lowered about a tilt axis, wherein the support structure has radially arranged spokes, which are interconnected by means of an inner support ring.

Such a machine is about for sintering or for

Making pellets usable.

For "pellets of iron ore" fine ores are rolled with the addition of water and additives to spherical packs, called green pellets, then dried, fired at high temperatures and finally cooled.

STATE OF THE ART

Usually, for the firing of pellets already proven for many years walking grates are used, which consist of individual grate carriages, which are connected to each other via a straight closed chain in the form of a top and a bottom strand. The disadvantage of this is the large height of traveling grate systems, because the upper and lower strand are arranged one above the other. Moreover, the grate carriages currently located in the lower strand can not be used for firing, but must be moved along. It has therefore been earlier efforts, this

To overcome disadvantages and to arrange all grate carriages in a plane, see, for example, US 4,575,055 A, which comprises an inner and outer circumferential support ring, are mounted on which rust truck, or DE 33 18 679 AI. There is a rotating, circular machine

disclosed in which from segment-shaped gas-permeable grids an annular endless grate band is formed. At a feeding point, the material is continuously fed in a certain layer height and removed after a revolution at an unloading again.

 The grates are surrounded by a revolving on wheels

Supported supporting structure and are arranged lowered at an unloading about a tilt axis. The support structure further has radially arranged spokes, which are interconnected by means of an inner support ring. On the outside, the support structure is supported by wheels attached to the spokes on circular rails.

 The disadvantage of this design is that through

different temperatures in different areas of the grate tape and due to the only at one end firmly connected to the support ring spokes this can deform at the free ends and thus a perfect

Functioning of the machine is no longer ensured.

PRESENTATION OF THE INVENTION

 It is now an object of the present invention to provide a pertinent annular machine in which deformation of the spokes can be prevented.

According to the invention for this purpose it is proposed according to claim 1, that the support structure further comprises an outer support ring, by means of which the spokes connected to each other are, wherein the spokes are fixedly connected to the inner support ring and the outer support ring and wherein the spokes or any covers of the spokes do not protrude above the plane of the grate upwards.

 The position of each spoke is thus fixed at its two longitudinal ends, there is no more free end, which is free

could deform.

 In that the spokes or any covers of the

Spokes do not go up above the level of the grate

protrude, it is ensured that the material to be thermally treated in the same thickness along the annular grating tape can be applied without the applied material ceiling is interrupted by rising spokes or their covers or the thickness of the material ceiling - as in DE 33 18 679 AI - varies. In any case, the latter results in uneven thermal treatment of the material, which should be avoided.

 The drive for the machine according to the invention can act on the outer support ring, which has the advantage that it is easier to access from the outside in comparison to a drive which engages the inner support ring. The drive can be designed for example as a friction wheel drive.

 As already known from DE 33 18 679 AI, it is

structurally easiest when the tilt axis of the grates is radial.

 To reduce the weight of the grates and thus their

To facilitate lowering and lifting, it may be provided that the inner and outer support rings form upwardly projecting inner and outer side walls beyond the plane of the grate. These side walls most easily follow the shape of the support rings, so are circular arc when the support rings are circular, or even when the support rings are formed as a polygon. So no need to be on the grid itself

Side walls are provided, as is often the case with conventional grate car.

 If the top of the spokes forms a plane with the top of the grate, then make sure that at

uniform application of material on the grate a

constant material thickness is achieved.

If the spokes have one or more openings at their top and bottom so as to allow passage of gas and / or heat through the spoke, it is ensured that the spokes are also on the spoke

Material is thermally treated. In particular, together with the embodiment where the top of the spokes forms a plane with the top of the grate, so can a uniform thermal treatment of the material

be ensured.

The openings in the top of the spokes can

advantageously be formed by one or more grate bars, which also form the top of the grate.

The grate is usually made of a carrier (which in turn may consist of individual support elements) on which the actual grate is attached. The material to be treated rests on the grate and is supplied with heat or gas through openings in the grate from below. The grate is usually made of individual grate bars, which are aligned, for example, transversely to the grate band, so here radially. The

Spokes can now be formed so that their top substantially by one or more of such

Grate bars is formed. The spoke can be sized so that you or your grate bars the same distance from each other - in the case of multiple grate bars - and to the

Grate bars of the neighboring grates, like the grate bars, have the grates. This results in a uniform for the entire machine grate surface, a uniform grate tape, which is constructed of the same grate bars with the same distance from each other.

So that the tilt axis or their joints are not in the

be located treating material, it can be provided that the tilting axis is below the spoke and along the tilting axis of each spoke one or more joints are provided which connect the spoke with the associated grate.

In order for the grate to be guided during unloading, it is provided in an embodiment of the invention that at the side of the grate opposite the joints on its

Bottom one or more wheels are arranged, with which the lowered at the unloading place rust on

Lowering rails can be performed.

To seal the space above the grates with respect to the spaces laterally therefrom, an attacking on both the inner and the outer support ring

Friction ring seal be provided, each with a

Friction ring on the inner and outer support ring is engaged.

The friction ring for the friction ring seal can simultaneously form the contact surface for the friction wheel of a friction wheel drive.

The horizontal guide of the support rings can be done by horizontal guide rollers which engage the inner support ring, in particular on a arranged on the outside of the support ring support ring guide rail. BRIEF DESCRIPTION OF THE FIGURES

The invention will be explained in more detail with reference to an embodiment. It shows

1 is a plan view of a sector-shaped section of a machine according to the invention, comprising two grates,

2 shows a longitudinal section through the grates of Fig. 1,

3 shows a longitudinal section through the grates of Figure 1 during the discharge.

4 shows a cross section through a grate and through the outer support ring in the region of the drive,

5 shows a cross section through a grate and through the inner support ring in the region of a guide roller,

Fig. 6 shows a cross section, which reveals the rust, the inner and the outer support ring.

WAYS FOR CARRYING OUT THE INVENTION

In Fig. 1 is a sector-shaped section of a

inventive machine comprising two grids la, lb. Between the two gratings la, lb a spoke 2b is provided, below which there is a joint 7, which is visible through a diagrammatic section through the spoke and around which the grate la is lowerable. The places where the spoke 2a connects to the grid la and where the spoke 2c connects to the grid lb are shown. The grates and spokes are alternately arranged around the entire circumference of the machine, so I am an annular Rostband results in which the individual grates are separated by spokes. The spokes 2 a - 2 c are fixedly connected to the inner support ring 3 and the outer support ring 4.

The inner support ring 3 is over several within the

Supporting rings arranged guide rollers 20 guided horizontally. The guide rollers 20 are fixed to a

Construction, about rotatable on vertical supports 26 (see Fig. 6). They have a game to the inner support ring 3, so that the support structure consisting of spokes and support rings does not get stuck even with temperature-induced deformations. On the inside of the inner support ring 3, an inner side wall 18 is provided for each individual grid 1a, 1b, so that the material to be treated in the

desired height can be poured and does not slip inwards over the inner support ring 3. At the top of the inner support ring 3, a friction ring 12 is externally provided, which serves as a contact surface for a friction ring seal 14, not shown here (see Fig. 6). Through a

Graphical section is one of the inner wheels 8 of the rust la visible.

At the top of the outer support ring 4 is outside a

Friction ring 13 attached, the attack surface for both the drive and for not drawn here

Friction ring seal 15 (see Fig. 6) is used. On the inside of the outer support ring 4, an outer side wall 19 is provided for each individual grid la, lb, so that the

treating material can be poured in the desired height and does not slip outwards over the outer support ring 4. By a graphic section of one of the outer wheels 9 of the grid la is visible. Each grid la, lb has on its underside a stop 24 with a horizontal support surface. On this

Stop 24 is supported by the adjacent spoke - in Fig. 1 would be the spoke 2a - on. The spoke then has, where it touches the support surface of the stop 24, a wear plate 27 (see Fig. 2).

The arrow 25 indicates the direction of movement of the grates or the supporting structure.

In Fig. 2 is a longitudinal section through the grates of Fig. 1, wherein one looks to the outside of the grids la, lb. One sees the spoke 2b between the posts 1a, 1b, the spoke 2c connected to the grid 1b, and the joint 7 arranged underneath each spoke.

Each rust in this example consists of five across

Direction of movement 25, equidistant from each other

arranged I-beams, those arranged on the left and right edges is only half executed. Of course, the number of I-beam depending on the purpose and size of the grate is variable. These I-beams are through in

Movement direction 25 arranged longitudinal beams connected together. This can be done by welding the longitudinal and the I-beams, but preferably the longitudinal and I-beams form a single casting, so that no welding is necessary. On the upper side of the I-beams, there are four grate bars 22 fixed per grille 1a, 1b, each holding the grate

 Bridge gap between the I-beams and the

Surface of the rust form la, lb. The grate bars 22 have openings so that gas can flow from bottom to top.

The grate bars 22 are inserted only in the I-beam and therefore can be easily replaced. It is also conceivable to build the grid of individual boxes. A box would then be two across

Moving direction consist 25 arranged carriers which form the side walls of the boxes and are connected to each other. The top can then form a grate bar 22. The box would therefore be similar to the spokes 2a-2c constructed, but the boxes are individually inserted into a basic construction and can be removed from this individually. If a grate bar 22 or a box is defective, the box can be easily removed and replaced with a new one.

The spokes 2 b, 2 c are also made of two half I-beams as the grids la, lb and are covered by a grate bar 22. On the side where the spoke 2b rests on the nearest grate lb, half the I-beam is inclined inwards at the bottom to allow lowering of the grate 1b.

Each grid la, lb has an inner wheel 8 (not here

visible) and an outer wheel 9, with which it on a circular inner guide rail 10 and outer

Guide rail 11 is supported (see Fig. 4-6). In Fig. 3, only the running surface 21 of the guide rail 11 is shown.

In Fig. 3 is a longitudinal section through the grates of Fig. 1 and Fig. 2 is shown in the discharge. For unloading, go in a horizontal plane

Guide rails 10, 11 in Absenkschienen 23 over, which are lowered down. Here they have one in

Moving direction sinking area, which has the shape of a straight line and in an upwardly curved

Transitions area, which in turn connects steadily to the horizontal guide rail 21. The upturned

Area has a greater slope than the sinking area. Since the grates la, lb are on the wheels 8, 9 on the

Support guide rails, tilt the grates on the

Joints 7 opposite sides down when the lowering rails 23 begin because the wheels 8, 9 the

Lowering rails 23 follow. The material on the grates slides down from the grate.

To assist in unloading the material, fixed scrapers 28 and / or movable scrapers 29 may be provided. The fixed scraper 28 is fixedly mounted with its sharp edge transverse to the direction of movement 25 in the region of the unloading point, in such a way that its edge is approximately at the level of the top of the grate bars 22. As a result, caking on the grate bars 22 of the

Spokes 2a-2c be cleaned when they pass under the fixed scraper 28.

The movable scraper 29 is here cylindrical

trained and can be rotated about its own longitudinal axis. The longitudinal axis of the movable scraper can be additionally pivoted in the vertical direction, so that the grates la, lb can be cleaned in the lowered state.

The unloading point occupies about 15-30 ° of the full circle of the machine according to the invention.

In Fig. 3 and the outer support ring 4 can be seen, which is supported in the region of the unloading, as well as the inner support ring 3, on its underside of support rollers 6 which rotatably on the upper edge of the not shown

Discharge bunker are stored. Outside the unloading the support rings 3, 4 on the grids la, lb and their wheels 8, 9 supported on the guide rails 10, 11. FIGS. 4-6 each show the same cross-section through a machine according to the invention, through one of the grates. Fig. 6 shows the entire width of the grate, while Fig. 4 only the left (outer), Fig. 5 only the right

 (inner) section of Fig. 6 show.

In Fig. 4 is one of the along the circumference of the outer

Tragrings 4 arranged Reibradantriebe 5 shown, which drives the outer support ring 4 via a friction wheel 16. The friction wheel 16 engages from below on the horizontal friction ring 13, wherein from above a pressure wheel 17 presses against the friction ring 13 to ensure that the friction wheel 16 abuts the friction ring 13.

At the top of the friction ring 13 engages the

Friction ring seal 15, which the of hot gases

flowed area over the racks la, lb, the hood 30, seals from the outside. Below the grids la, lb hot gas is supplied via the windbox 31, of which a part of the wall 32 is located.

5, the inner support ring 3 are shown with its horizontal friction ring 12 analogous to FIG. 4, on which the friction ring seal 14 engages from above. Furthermore, an upwardly outwardly inclined, attached to the inner support ring 3 inner

Sidewall 18 located. On the outer circumference of the inner support ring 3, a support ring guide rail 33 is provided to engage guide rollers 20 which are mounted on beams 26. The grids la, lb run with their respective inner wheel 8 on an inner guide rail 10th

In Fig. 6, in addition to the devices discussed in FIGS. 4 and 5, the hot blast line 34 is also located, which hot gas, such as for burning

Pellets on the racks la, lb, in the wind box 31 feeds. In the machines described here, the outer support ring has a diameter of about 23 m. There are two Reibradantriebe 5 are provided.

REFERENCE LIST la, lb Grates

 2a, 2b, 2c spokes

3 inner support ring

 4 outer support ring

5 friction wheel drive

 6 support rollers

 7 joint

 8 Inner wheel of rust

 9 Outer wheel of rust

10 Inner guide rail

 11 Outer guide rail

 12 friction ring on the inner support ring 3

 13 friction ring on the outer support ring. 4

 14 Friction ring seal for inner support ring 3 15 Friction ring seal for outer support ring 4

16 friction wheel

 17 pressure wheel

 18 inside sidewall

 19 Outer side wall

20 guide rollers

 21 running surface of the guide rail 11th

 22 grate bar

 23 ascending rail

 24 stop

25 direction of movement

26 carriers wear plate

fixed scraper

movable scraper

Hood

 windbox

 Windbox wall 31

Support ring guide rail

Hot air line

Claims

claims 1. Ring-shaped machine for thermal treatment of  Solids, in particular for the production of pellets from iron ore, comprising a plurality of gas-permeable grids (1a, 1b), which circulates on wheels  Support structure (2a-2c, 3, 4) are supported and which are arranged lowered at an unloading about a tilt axis, wherein the support structure radially arranged spokes (2a-2c) which are interconnected by means of an inner support ring (3),  characterized in that the support structure further comprises an outer support ring (4) by means of which the spokes (2a-2c) are interconnected, wherein the spokes (2a-2c) with the inner support ring (3) and the outer support ring (4) fixed and with the spokes or any covers of the spokes upwards not above the plane of the grate (la, lb)  protrude. 2. Annular machine according to claim 1, characterized  characterized in that a drive is provided which drives the outer support ring (4), such as a  Friction wheel drive (5). 3. Annular machine according to claim 1 or 2, characterized characterized in that the tilting axis is radial. 4. Annular machine according to one of claims 1 to 3, characterized in that inner and outer  Support ring (3, 4) upwardly beyond the plane of the grate (la, lb) outwardly projecting inner and outer side walls (18, 19) form. 5. Annular machine according to one of claims 1 to 4, characterized in that the upper side of the spokes (2a-2c) forms a plane with the upper side of the grate (la, lb). 6. An annular machine according to any one of claims 1 to 5, characterized in that the spokes (2a-2c) have at its top and at its bottom one or more openings, so that a passage of gas and / or heat through the spoke is possible , 7. Annular machine according to claim 6, characterized  in that the upper side of the spoke (2a-2c) is formed by one or more grate bars (22) which form the upper side of the grate (1a, 1b). 8. Annular machine according to one of claims 1 to 6, characterized in that the tilting axis is below the spoke (2a-2c) and along the tilting axis of each spoke one or more joints (7) are provided, which connect the spoke (2a-2c) with the associated grate (1a, 1b). 9. Annular machine according to claim 8, characterized  characterized in that at the joints (7) opposite side of the grate (la, lb) on its underside one or more wheels (8, 9) are arranged, with which the lowered at the discharge point grate on lowering rails (23) are guided can. 10. Ring-shaped machine according to one of claims 1 to 9, characterized in that for sealing the space (30) over the grates (la, lb) opposite to the side thereof located spaces on both the inner and outer support ring (3, 4) attacking  Friction ring seal (14, 15) is provided, which is in engagement with a respective friction ring (12, 13) on the inner and outer support ring. 11. Annular machine according to claim 10, characterized  characterized in that the friction ring (13) for the  Friction ring seal (15) at the same time the attack surface for the friction wheel (16) of a friction wheel drive (5). 12. Annular machine according to one of claims 1 to 11, characterized in that the horizontal guidance by horizontal guide rollers (20) takes place, the inner Support ring (3) attack, in particular arranged on an outer side of the support ring support ring guide rail (33).