WO2009155974A1

WO2009155974A1 - Device for separating a solid material and a gas and plant for producing cement

Info

Publication number: WO2009155974A1
Application number: PCT/EP2008/058102
Authority: WO
Inventors: Verena Georg; Detlev Kupper; Luis Lagar Garcia; Andreas Hoppe; Heinz-Werner Thiemeyer; Daniel Klegraf; Thomas Deck; Stefani Richter
Original assignee: Polysius Ag
Priority date: 2008-06-25
Filing date: 2008-06-25
Publication date: 2009-12-30

Abstract

The device according to the invention for separating a solid material and a gas is made substantially of a helical and/or spiral pipeline in which a gas-solid suspension is separated into a solid stream and a gas stream by centrifugal forces, a solid material pipeline connected to the end of the helical and/or spiral pipeline for removing the solid material stream, and a gas line connected to the end of the helical and/or spiral pipeline for removing the gas stream. Mechanical fixtures are further provided in the helical and/or spiral pipeline for spatially bounding the two flows, said fixtures gradually increases in the flow direction of the gas-solid suspension. Alternatively, the helical and/or spiral pipeline can also comprise a cross-sectional shape forming, for at least one of the two flows, a groove or channel-like boundary to the other flow, wherein the groove or channel-like boundary gradually increases in the flow direction of the gas-solid suspension.

Description

Device for separating a solid and a gas, and a plant for cement production

The invention relates to a device for separating a solid and a gas and a plant for cement production.

In the cement and minerals industry, systems comprising DC heat exchangers and cyclone separators are known in particular for preheating, cooling and / or calcining fine-grained materials. Most such devices have a plurality of superimposed stages, wherein the gas stream is passed from bottom to top through all stages, while the solid is fed in the opposite direction to the individual stages. At the end of each stage, the solid is separated from the gas.

Such systems have the disadvantage that they require a huge height and the degree of separation in the cyclone is not always satisfactory. Thus, in the cyclones, there are often uncontrolled flows which are caused, for example, at the cyclone inlet by superposition of the inlet gas flow with the eddy current formed in the cyclone or by reversal of the gas flow direction in the cone of the cyclone. Furthermore, it can be used to re-entrust the already

Cyclone edge deposited particles come into the gas inlet flow of the cyclone.

From DE 197 38 912 Al a device and a method for separating solids from a carrier stream is known in which a curved line opens into a filter system. In the curved line is in the connection area to the

Filter system provided a Leitzunge to separate the partial flows generated in the curved line. Furthermore, DE 103 09 575 A1 discloses a cyclotron for separating particles from a gas-particle mixture, in which a 90 ° curved intake duct opens into a cyclotron separator, wherein a dividing wall is provided in the intake duct after the bend in order to provide a

Avoid mixing the already separated particles. Another problem with cyclone separators is that in different sized designs, the centrifugal forces change at the same inlet velocities and thereby result in different separation conditions.

In US 4,318,697 therefore a multi-stage preheater for cement raw material has been proposed, the individual stages each consist of a riser and a subsequent helical and / or spiral-like line. The riser and the helical and / or spiral lines are connected to each other via a deflection arc. The helical and / or spiral line also has a rectangular cross-section and is connected to a side surface of a cuboid deposition chamber. The connection point extends over the entire side surface of the cuboid deposition chamber. The lower part of the separation chamber tapers in a funnel shape and serves to discharge the solid while the gas is discharged upwards. The degree of separation is insufficient.

The invention is therefore based on the object to improve the separation efficiency of the device for separating a solid and a gas.

According to the invention, this object is solved by the features of claim 1.

The device according to the invention for the separation of a solid and a gas consists according to a first embodiment substantially of a helical and / or spiral-like line, in which by centrifugal forces a

Gas-solid suspension are separated into a stream of solids and a gas stream, one of the end of the helical and / or spiral-like line in communication solid line for discharging the flow of solids and a gas conduit communicating with the end of the helical and / or spiral conduit for draining the gas flow.

Furthermore, mechanical fittings for the spatial delimitation of the two streams are provided in the helical and / or spiral line, which gradually build up in the flow direction of the gas-solid suspension.

According to a second embodiment, the device for separating a solid and a gas consists essentially of a helical and / or spiral line in which a gas-solid suspension is separated by centrifugal forces into a solids flow and a gas flow, one with the end the helical and / or spiral-like line in communication solid line for discharging the solids flow and a communicating with the end of the helical and / or spiral-like line gas line for discharging the gas flow.

Furthermore, the helical and / or spiral line has a cross-sectional shape which forms a channel or channel-like delimitation to the other stream for at least one of the two streams, wherein the channel or channel-like boundary gradually builds up in the flow direction of the gas-solid suspension ,

Under a helical and / or spiral-like line according to the invention, a line is understood, which is at least partially helical and / or helical. The rotation of the helical and / or spiral-like line can in particular only extend over a smaller angular range, for example 90 °.

In the experiments underlying the invention, it has been shown that in the helical and / or spiral line due to the centrifugal forces, a separation of solids flow and gas flow takes place. If the dividing wall between the two streams is provided shortly before entry into the deposition chamber, as is the case in DE 103 09 575 A1 or DE 197 38 912 A1, it may in this area lead to undesired turbulence and thus in turn come to a mixing of the two streams. Due to the gradual construction of the mechanical installations or the gutter or channel-like

Distinction by the cross-sectional shape of this effect can be avoided, so that a better degree of separation is achieved.

The gradual construction of the mechanical installations, which are formed for example by one or more partitions, is to be understood in such a way that the installations change as they become larger and form an increasingly clear demarcation. Similarly, the channel or channel-like delimitation in the flow direction is becoming larger and more pronounced.

Further embodiments of the invention are the subject of the dependent claims.

According to an advantageous embodiment of the invention, the mechanical installations or the channel or channel-like delimitation in the flow direction can build up so far that at the end of the helical and / or spiral line two completely separate channels for the

Solid stream and the gas stream are present.

In accordance with a further embodiment of the invention, a deposition chamber communicating with the end of the helical and / or spiral-type conduit is provided, to which the solids conduit for discharging the solids flow and the

Gas line are connected to divert the gas flow. Furthermore, a riser can be provided, which is followed by the helical and / or spiral line. The riser is in particular formed as an ascending line and the helical and / or spiral-like line as a descending line, wherein a deflection head is provided between the lines. According to an advantageous embodiment of the invention, the mechanical installations or the channel or channel-like delimitation extend through the cross-sectional shape over at least 50%, preferably over at least 75% of the length of the helical and / or spiral line.

The above-described apparatus for separating a solid and a gas is also particularly suitable for being arranged in a plurality of stages arranged one above the other. In this case, each stage has a riser, a subsequent helical and / or spiral-like line and a solid line connected to the end of the helical and / or spiral line and a gas line, wherein the gas line of a stage in the riser of the next higher Stage passes and the solid line of a stage in the riser of the next lower level opens.

A one-stage or multi-stage arrangement of the device for separating one

Solid and a gas can be used in particular as a preheater and / or calciner in a plant for cement production.

Further advantages and embodiments of the invention will be explained in more detail below with reference to the description of some embodiments and the drawings.

In the drawing show

1 is a side view of a stage of the inventive device,

2 is a rotated by 90 ° side view of FIG. 1,

3 is a plan view of the stage of FIG. 1, 4 to 6 cross sections in an upper, middle and a lower portion of the helical or spiral line for illustrating various embodiments of mechanical installations,

7 to 9 further examples of the mechanical installations at the end of the helical or spiral line,

10 embodiment for different cross-sectional shapes of the helical or spiral line in an upper, middle and a lower portion of the helical or spiral line,

11 to 14 further examples of cross-sectional shapes of the helical or spiral line,

FIG. 15 is a schematic representation of an exemplary embodiment with guide ribs for discharging the solids flow, FIG.

16 to 19 different cross-sectional profiles with comb or pocket-like

Profiles in the area of the solids stream,

Fig. 20 is a side view of the device with three superposed stages and

21 is a plan view of the device according to FIG. 20.

Fig. 22 is a three-dimensional representation of a plant for cement production.

In the apparatus shown in Figures 1 to 3 for the separation of a

Solid and a gas is, for example, a device for preheating, cooling and / or calcination of fine-grained material in the

Cement production. It essentially consists of a helical and / or spiral-like line 1, in which by centrifugal forces a gas-solid suspension in a stream of solids 2 and a gas stream 3 is separated, connected to the end of the helical and / or spiral line 1 in communication solid line 4 for discharging the solids flow and a with the end of the helical and / or spiral-like line in communication gas line 5 to

Deriving the gas flow. Further, a riser 6 and a arranged between the riser 6 and the helical and / or spiral-type conduit 1 deflection head 7 is provided.

The end of the helical and / or spiral line 1 opens into a

Separating chamber 8 to which the solid line 4 are connected for deriving the solids flow 2 and the gas line 5 for discharging the gas stream 3.

The deposition chamber 8 has, in the connection region to the helical and / or spiral line 1, a cylindrical section which merges into the gas line 5. However, the gas line 5 can also protrude in the manner of a dip tube in the deposition chamber 8. The lower part of the deposition chamber 8 tapers in a funnel shape and merges into the solid line 4. The helical and / or spiral-like line 1 preferably opens into the deposition chamber 8 at a pitch angle α with respect to the horizontal of at least 30 °, preferably between 30 ° and 60 °.

The gas 3 is discharged at the inner wall of the cylindrical part of the deposition chamber 8 with a twist up into the gas line 5. The obliquely downwardly directed flow into the separation chamber 8 also prevents a superposition of the inlet gas flow with the swirl flow formed in the separation chamber in the region of the mouth of the helical and / or spiral line 1. In order to achieve a good pre-separation of the solids flow and the gas flow already in the helical and / or spiral line 1, mechanical installations 9 are provided for the spatial delimitation of the two streams in the helical and / or spiral line, which are in the flow direction of the gas Gradually build up the solid suspension.

In the figures 4 to 6 various embodiments are shown, the mechanical installations 9 for the spatial delimitation of the two streams. In each figure, three cross sections through the helical and / or spiral line 1 are shown, wherein in each case a cross section in the upper, middle and lower region of the helical and / or spiral line 1 is shown. In all three embodiments, the internals 9 are formed so that at least at the end of the helical and / or spiral-like line 1, two completely separate sub-channels are formed, so that the solid stream 2 and the gas stream 3 at different locations in the deposition chamber or directly in the solids line

4 or gas line 5 can be derived. The mechanical installations 9 are formed, for example, by at least one partition, which builds up in the flow direction on and on. In the illustrated embodiment, the structure goes so far that there are two completely separate sub-channels.

The shape and the required length for the complete construction of the mechanical installations 9 is particularly adapted to the material to be treated, the gas velocities and the centrifugal forces acting. The cross-sectional shape of the helical and / or spiral line 1 is important here. In order to keep the pressure losses as low as possible, the mechanical internals are expediently dimensioned so that they have curved shapes.

In the figures 7 to 9 further embodiments are shown, wherein in each case only one cross section in the region of the end of the helical and / or spiral-like line 1 is shown, where the two areas for the solids flow and the gas flow are again completely separated from each other. In the embodiments, the left lower portion for the flow of solids and the upper right portion for the gas flow is provided.

The mechanical fittings 9 are preferably installed statically. However, it would also be conceivable that at least a portion of the mechanical internals is movable, thereby enabling fine tuning before or during operation.

In addition to internal mechanical installations 9, the delimitation of solids flow and gas flow in the helical or spiral conduit 1 could also be formed by a suitable cross-sectional shape which forms a channel or channel-like delimitation from the other flow for at least one of the two streams. Again, it is envisaged that the gutter or channel-like boundary gradually builds up in the flow direction of the gas-solid suspension.

Such an embodiment is shown in the three cross sections of Fig. 10, wherein from left to right, a section in an upper, middle and a lower portion of the helical or spiral-like line 1 is shown. The cross section of the helical and / or spiral line is rectangular, with the lower left

Corner forming a channel or channel-like boundary Ia for the flow of solids, which is getting deeper in the flow direction. Of course, also in this embodiment, it can be provided that the channel or channel-like delimitation Ia is completely closed at the end of the helical and / or spiral line.

The exemplary embodiments illustrated in FIGS. 11 to 14 show, however, that the channel-like delimitation Ia is not restricted to a rectangular shape. Whether a rectangular, triangular or partially rounded cross-sectional shape for this channel or channel-like boundary Ia into consideration depends on the purpose of use and the gas-solid suspension used. The other geometry of the line 1 is to be considered here.

The mechanical installations 9 or the channel-like or channel-like delimitations Ia may extend in particular over at least 50%, preferably over at least 75%, of the length of the helical and / or spiral line 1.

However, the mechanical fittings 9 can also be formed by a plurality of guide ribs 10, as shown schematically in FIG. 15. The guide ribs 10 are expediently arranged where the solid due to the

Centrifugal forces accumulates. On or between these Leitrippen 10, the solids flow can be selectively performed.

Furthermore, on the outside of the helical and / or spiral line 1, where the solid accumulates, in addition, a separator 11 may be provided, for example, a Kammpro f oderl or a Taschenpro fil has (see Figures 16 to 19).

By the separator 11 and the guide ribs 10 can be further prevented that the already deposited material runs along the outer wall and, if necessary, again torn by the gas flow.

The helical or spiral line 1 is expediently dimensioned such that at least at the gas inlet into the line a significant increase in the centrifugal forces acting on the solid takes place. This can be done both by a

Speed increase as well as by reducing the radius of curvature to the axis of the device done. A combination of both is also useful.

The cross-sectional shape of the helical or spiral line 1 should expediently have an aspect ratio between 1: 2 and 1: 3. The The slope of the helical line 1 is preferably between 40 ° and 80 ° to the horizontal (relative to the center line of the spiral). In addition, the helical or spiral line 1 should be steep enough so that the material can drain and does not lie.

In the context of the invention, it is conceivable that the radius and / or the slope and / or the cross-sectional shape and / or the cross-sectional size of the helical and / or spiral line 1 changes in the flow direction of the gas-solid suspension. In this way, on the one hand influence on the pre-separation of the gas-solid suspension in the range of helical and / or spiral-like line can be taken and on the other hand, the helical and / or spiral line 1 can be adapted to external conditions. This is particularly advantageous when several stages are interleaved and arranged one above the other.

The radius, pitch, cross-sectional shape and / or cross-sectional size can change continuously in the flow direction and / or at least in one section. For example, a radius reduction causes an increase in centrifugal force, while a radius increase corresponds to a decrease in centrifugal force. By changing the cross-sectional shape and size, influence on the flow velocity can be made.

In the above-described devices for separating a solid and a gas, the incoming gas stream may come, for example, from one of the following aggregates, plant components or elements:

From another unit for the separation of solids from gas streams or dedusting, for example from a cyclone, in particular from a

preheater;

From a combustion unit, such as a rotary kiln, a

Combustion chamber, a calciner, a fluidized bed or a hot gas generator; - From an aggregate for heat exchange, such as a bulk material cooler or an air-to-air heat exchanger;

- From a device for power generation or energy storage.

The escaping gas stream can in particular be supplied to the following units or plant components:

an aggregate for the separation of solids from gas streams or

Dedusting, for example a cyclone or a next preheater stage;

a combustion unit, for example a combustion chamber or a calciner;

- An aggregate for heat exchange, such as an air-to-air heat exchanger;

- an aggregate for electricity, energy production or energy storage.

The separated solids stream can in particular be supplied to one of the following aggregates or plant components:

an aggregate for the separation of solids from gas streams or for dedusting, for example a cyclone or a next preheater stage;

a combustion unit, for example a rotary kiln, a combustion chamber or a calciner;

- a heat exchanger. If units, system parts or stages with different static pressures are connected to each other via lines, air blocking means are expediently attached.

The devices described above for carrying out chemical and / or physical reactions between a solid and a gas are characterized by a low pressure loss and a high separation efficiency. In addition, a very compact design can be realized, which has a significantly reduced height, especially in suspended gas heat exchangers.

In the following, a device with three stages I, II, III is described with reference to FIGS 20 and 21, which is, for example, a three-stage preheater for cement raw material. Each individual stage can be designed according to the embodiments described above.

In such a multi-stage arrangement, a solid to be treated in the uppermost stage III is fed via a solids line 4 '"and discharged as treated solids stream 2 from the lowest stage I. The solid line one stage opens in the riser of the next lower stage, while the gas line of one stage merges into the riser of the next higher stage.

While the solid is thus passed from top to bottom through the three stages, the gas flows through the arrangement in the reverse direction. The gas stream 3 to be supplied to the bottom stage is, for example, the hot exhaust gas of a furnace or of a calciner. The gas stream 3 "discharged in the third stage via the gas line 5" is fed, for example, to a filter or a downstream, highly efficient separator for dedusting The treated solids stream 2 passes, for example, into a calciner or an oven for further processing. By forming the device with a riser 6 and a descending, helical or spiral-like line 1, the three stages can be arranged very compact and intertwined. It is further provided that the helical or spiral-like lines 1, Y, 1 "of at least two successive stages are alternately formed left and right turn

(see Fig. 21).

Finally, FIG. 22 shows a three-dimensional representation of a plant for the heat treatment of fine-grained material in cement production with a rotary kiln 100, a calciner 200 and a preheater 300. The calciner

200 and / or the preheater 300 may be formed according to the device described in Figures 1 to 21.

Claims

Claims:

1. A device for separating a solid and a gas, with a helical and / or spiral-like line (1), in which by centrifugal forces a gas-solid suspension in a solids flow (2) and a gas stream (3) are separated, one with the end of the helical and / or spiral-like line (1) in communication solid line (4) for discharging the solids flow and - one with the end of the helical and / or spiral line (1) in

Connecting gas line (5) for diverting the gas stream,

characterized in that in the helical and / or spiral line mechanical installations (9) are provided for the spatial delimitation of the two streams, which gradually build up in the flow direction of the gas-solid suspension.

2. A device for separating a solid and a gas with a helical and / or spiral line (1), in which by centrifugal forces a gas-solid suspension in a solids flow (2) and a gas stream (3) are separated, a with the end of the helical and / or spiral line (1) in

Connecting solid line (4) for discharging the solids flow and - one with the end of the helical and / or spiral line (1) in

Connecting gas line (5) for diverting the gas stream,

characterized in that the helical and / or spiral line a

Has cross-sectional shape, which forms at least for one of the two streams a channel or channel-like boundary (Ia) to the other stream, wherein the gutter or channel-like boundary gradually builds up in the flow direction of the gas-solid suspension.

3. Device according to one of claims 1 or 2, characterized in that with the end of the helical and / or spiral-like line (1) in connection standing Abscheididekammer (8) is provided, to which the solid line (4) for discharging the Solid stream (2) and the gas line (5) for discharging the

Gas stream (3) are connected.

4. Device according to one of claims 1 or 2, characterized in that further comprises a riser (6) is provided, to which the helical and / or spiral-like line (1) is connected.

5. Apparatus according to claim 4, characterized in that the riser (6) as ascending line and the helical and / or spiral-like line (1) as a descending line with an inclination of at least 30 ° relative to the

Horizontal are formed and between the two lines

Deflection head (7) is provided.

6. Device according to one of claims 1 or 2, characterized in that the helical and / or spiral line (1) in the region of the delimited solid stream at least one separator (11) on its outer side.

7. The device according to claim 1, characterized in that at least part of the mechanical installations (9) is statically installed.

8. The device according to claim 1, characterized in that at least a part of the mechanical installations (9) is movable.

9. The device according to claim 1, characterized in that the mechanical installations (9) build up in the flow direction so far that on End of the helical and / or spiral line (1) two completely separate channels for the solids flow (2) and the gas stream (3) are present.

10. The device according to claim 2, characterized in that the channel or channel-like delimitation (Ia) builds up in the flow direction so far that at the end of the helical and / or spiral line (1) has two completely separate channels for the flow of solids ( 2) and the gas stream (3) are present.

11. The device according to claim 1, characterized in that the mechanical installations (9) over at least 50%, preferably over at least 75%, the length of the helical and / or spiral-like line (1) are provided.

12. The device according to claim 2, characterized in that the channel or channel-like delimitation (Ia) by the cross-sectional shape over at least 50%, preferably over at least 75%, the length of the helical and / or spiral line (1) ,

13. Device according to one of the preceding claims, characterized in that the helical and / or spiral line (1) has round and / or angular cross-sectional areas.

14. The device according to one or more of the preceding claims, characterized in that a plurality of superimposed stages (I, II, III) are present, each having a riser (6), an adjoining helical and / or spiral line ( 1) and a solid line (4) connected to the end of the helical and / or spiral line and having a gas line (5), wherein the gas line of a stage merges into the riser of the next higher stage and the solid line of a

Level in the riser of the next lower level opens.

Plant for cement production with a preheater (300), a calciner (200) and an oven (100), wherein the preheater (300) and / or the calciner (200) at least one device according to one or more of the preceding claims 1 to 14 has.