EP3300505B1 - Device and method for conveying bulk solid materials - Google Patents

Description

The invention relates to a device for conveying bulk material according to the preamble of claim 1 and a method for conveying bulk material according to claim 10. The bulk material, which can be pasty, powdery, lumpy, freely flowable / freely flowing or cohesive conveyed material, in a printing room are promoted.

Such conveyors or pumps, which are also referred to as dry matter pumps, are used for introducing dry bulk materials, such as coal, into a pressurized space, such as a gasification reactor. When processing coal in gasification reactors, high temperatures and / or pressures of 25 bar to 80 bar are common for efficient operation of the plant. Especially with regard to the gasification of coal of low quality or with fuels from biomass, certain requirements cannot be neglected with regard to the conveyance of the respective bulk material.
Usually, there should be no high costs for the provision of the basic material, which includes its movement, comminution, classification and storage. In addition, the conveying devices should be robust and inexpensive and the escape of process gas, which leads to pressure losses, should be largely avoided during the conveying process. In addition, it must be taken into account that bulk goods in the form of fuels in particular have very different characteristics and often have fluctuations in terms of residual moisture or moisture content, are coarse-grained or even have aggressive properties or properties that attack the surface of the conveyor device.

The loss of process gas with which the required pressure is generated in the conveying device or a working area of the conveying device with respect to the ambient pressure is fundamentally dependent on the respective sealing of the working area. On the one hand, there are conveying devices, such as piston pumps, disk pumps, cell locks or pressure vessels arranged one behind the other, in which sealing is achieved by means of geometrically defined components. Are used mechanical seals, piston rings, or soft and hard sealing components running against each other.

The bulk material to be conveyed has an influence on the sealing effect of the components insofar as the components wear faster or slower, depending on the nature of the bulk material. When designing such conveyor devices, a compromise between the wear of the components and their replacement and the tightness must therefore often be made with regard to the sealing effect.

Most of the conveying devices or dry matter pumps mentioned at the beginning are relatively expensive, have a high energy loss and are overall very inefficient. From the WO 95/06610 A1 or the US 4 197 092 A For example, conveyor devices can be found that use seals in the form of material plugs made of material to be processed. These devices continuously feed the material into the pressure chamber. However, both require a great deal of energy in order to compress the material plug to such an extent that the desired sealing effect is achieved. The entire bulk material to be conveyed must be compacted in the conveying process either continuously or discontinuously to the density of the desired material plug. This is particularly difficult with inhomogeneous materials and also results in high wear on the components that come into contact with the plug.

In addition, the entire material to be conveyed must be prepared before the conveying process so that it can pass through the device and the compression path. This increases the effort required to process the bulk material before the conveying process.

From the EP 1 932 787 A1 on the other hand, a solids pump is known in which the delivery of the solids flow is regulated discontinuously by means of a valve. The valve is also sealed off from the pressure chamber by means of a material seal that is created by compressing the flow of solids to be conveyed.

In contrast, the Die reveals US 4,043,471 A discloses a solids pump in which material seals consisting of several layers of material are produced from a separate sealant supply in an auxiliary device with a rotating mechanism and are subsequently introduced into the delivery pipe of the pump. The material seals then create several smaller sealing areas within the delivery line of the solids pump.

In contrast, the object of the present invention is to convey bulk material into a pressure chamber with as little energy expenditure as possible and to guarantee the conveyance independently of fluctuating material properties. The disadvantages known from the prior art and mentioned above are to be overcome.

This object is achieved according to the invention by a device according to claim 1 and a method according to claim 10. Advantageous further developments and subject of the dependent claims.

The invention provides a device for conveying bulk material with a movable conveying member and an outer wall that is fixed relative to the conveying member, the device being pressurizable or being connected to a further processing chamber or a pressure chamber for receiving and further processing the bulk material. A dynamic seal seals off the differential pressure between the processing chamber and the upstream areas. This means that the dynamic seal, which is arranged in the conveying device, has to withstand the differential pressure between the further processing chamber and the areas located upstream of the process, for example the ambient pressure or a bulk material supply. A dynamic seal is understood to mean a component or an element which ensures the sealing effect between a movable part and a fixed part of the conveying device. In the present invention, a sealing element of the dynamic seal is provided from a sealant in the form of a material template or material seal that can be regenerated during operation of the conveying device, the sealing element, unlike known conveying devices, only from a partial flow of the bulk material to be conveyed or from a partial flow of the bulk material to be conveyed and a separate sealant supply is provided.

This has the advantage that no energy has to be applied to compress the entire bulk material flow, but only for the partial flow or the partial flow and the separate sealant flow. In addition, only a part of the bulk material is changed in terms of its original properties, so that there is no need to restore the original properties before entering or entering the printing room.
Nevertheless, the sealing element made of the bulk material or separate sealant acts like a regenerable sacrificial seal and the abrasion that inevitably occurs during operation can be used / further processed in the gasification process.
Grooves or depressions that are formed due to wear, for example on the inside of the conveying device, are compensated for by the regeneration of the sealing element with the bulk material or sealant and the associated filling of the depressions in the course of the process.
A conveyor device with a very long service life and low energy costs for sealing can thus be produced.

The sealing element of the dynamic seal can be provided as a primary or secondary seal. In the case of a primary seal, the sealing element of the dynamic seal consists entirely of the material of the bulk part stream or a separate sealant stream or a mixture of both. As an alternative to this, the sealing element can have a conventional shaping envelope component and the filling of this envelope component from the partial flow of the bulk material or the sealant flow can be provided as a secondary seal. In the secondary seal, the sealing effect of the sealing element results from the interaction of the envelope component and the filling.

A further development of the invention provides that the dynamic seal is provided as a translational or rotary seal on the movable conveyor element or the fixed outer wall of the conveyor device.
This can be used, for example, in a conveyor device which comprises a cylinder and in which a piston which is movable back and forth in the cylinder is provided as the conveyor element. Here the dynamic seal can be arranged both radially on the cylinder wall or on the piston.
Accordingly, the sealing element of the dynamic seal can be shaped as a sealing jacket in the form of the material template or material seal.
It is advantageous here if the sealing jacket has the smallest possible wall thickness, which is on the one hand large enough to withstand the forces and pressures occurring during operation and on the other hand is so small that only a small mass and / or a small volume of the material template or material seal is present.
The sealing effect is improved if the compression device, the compression path that can be covered by the compression device, the sealing space, the cylinder, the shape and the resistance of the piston are coordinated with one another in such a way that, in the case of a compaction caused by the compression device, the sealing material is forced to strive radially outwards becomes.

As an alternative to this, the sealing element of the dynamic seal can also be arranged as a plug or disk on the end face of the piston which can be moved back and forth. Either a plug that has already been compacted or a disc that has already been compacted can be used here, or a compression device can be arranged in such a way that sealing material brought into the conveying device can be processed to form a sealing element.

With regard to the material composition of the sealing element of the dynamic seal, one or more additives can be added to the partial flow of the bulk material and / or the separate sealant flow. Advantageously, these additives only have characteristics that are inert with regard to further processing in the pressure chamber. Thus, the material properties of the bulk material to be conveyed are not negatively influenced by the separate sealant flow or the additives.
Water, oil, for example waste oil, graphite, grease or other lubricants, preferably with good sliding and / or lubricating properties, are conceivable as additives. On the one hand, the additive preferably optimizes the sliding properties of the sealing element on the conveying device and, on the other hand, in particular in the case of liquid additives, the flowability of the sealing material is improved in order to improve the supply of the sealing material for regeneration of the sealing element.

A further development of the invention also provides that the sealing element of the dynamic seal is made of a pasty or liquid material. This characteristic can be adjusted by adding liquid additives. The advantage of this property is the improved conveying capacity of the sealing element for the purpose of regeneration. Removed sealing element is replaced by supply under pressure from a supply.

Furthermore, the invention provides a method for conveying bulk material into a pressurized space, in which a sealing element of a dynamic seal consists of a partial flow of the bulk material flow to be conveyed or a partial flow of the bulk material flow to be conveyed and a sealing element for sealing a conveying device from the ambient pressure or bulk material supply separate sealant flow is formed.
Sealant from the partial flow or partial flow and sealant flow can be conveyed continuously or discontinuously and / or compressed in a work space of the conveying device that can be used for compression by means of a movable conveying element.
Even if the sealant that is supplied to the bulk material flow during operation of the conveyor device is removed from a separate sealant flow, it can be processed together with the bulk material to be conveyed in the pressure chamber or the further processing chamber, since this does not change or deteriorate the material properties of the bulk material. The same applies to a sealant that has been removed from the bulk material flow and to which additives have been added in order to possibly improve the cohesion or the sliding properties.

In this way, on the one hand a stable conveying device and on the other hand an efficiently operable conveying device is realized.

Fig. 1

in schematischer Darstellung eine erste Ausführungsform einer erfindungsgemäßen Fördervorrichtung eingebettet in ein erfindungsgemäßes Verfahren;

Fig. 2

einen Schnitt entlang der Linie II durch die Fördervorrichtung aus Fig. 1 im Bereich einer Dichtstoffzuführeinheit;

Fig. 3

den Zustand der Fördervorrichtung bei Entfernen einer Komprimiereinrichtung von einem erzeugten Dichtelement und bei gleichzeitiger Bewegung eines Kolbens der Fördervorrichtung in Richtung einer Weiterverarbeitungskammer;

Fig. 4

den Zustand des Aufeinanderzubewegens des Kolbens und der Komprimiereinrichtung bei Kompaktierung des Dichtelements;

Fig. 5

den Zustand der Fördervorrichtung bei dem Unterdrucksetzen des Schüttgutstroms durch den Kolben;

Fig. 6

den Augenblick des Einbringens des Schüttgutes in die Weiterverarbeitungskammer;

Fig. 7

den Zustand des Evakuierens des Arbeitsraums der Fördervorrichtung;

Fig. 8

eine zweite Ausführungsform einer erfindungsgemäßen Fördereinrichtung;

Fig. 9

eine Darstellung des erfindungsgemäßen Verfahrens.

The invention is explained in more detail below with the aid of drawings, in which different exemplary embodiments are shown. Show it:

Fig. 1

a schematic representation of a first embodiment of a conveyor device according to the invention embedded in a method according to the invention;

Fig. 2

a section along the line II through the conveyor Fig. 1 in the area of a sealant supply unit;

Fig. 3

the state of the conveying device when a compression device is removed from a generated sealing element and with a simultaneous movement of a piston of the conveying device in the direction of a further processing chamber;

Fig. 4

the state of the piston and the compression device moving towards one another when the sealing element is compacted;

Fig. 5

the state of the conveyor when the bulk material is pressurized by the piston;

Fig. 6

the moment when the bulk material is brought into the processing chamber;

Fig. 7

the state of evacuation of the working area of the conveyor;

Fig. 8

a second embodiment of a conveyor device according to the invention;

Fig. 9

a representation of the method according to the invention.

The figures are only schematic in nature and only serve to understand the invention. The same elements are provided with the same reference symbols.

In Fig. 1 A first embodiment of a conveyor device 1 according to the invention is shown. The conveying device 1 is designed as a solids pump. It has a cylinder 3 as a fixed outer wall and a piston 8 as a movable conveying member. The fixed outer wall 3 also defines a working space 2 in which the piston 8 can be moved back and forth along a longitudinal axis 7. The work area 2 can be filled with bulk material 4. The bulk material 4 is removed from a bulk material supply which comprises a feed device 5 with a screw conveyor 6.

A sealing gap 10 is present between the outside of the piston 8 and an inside or inside surface 9 of the cylinder 3. The sealing gap 10 is sealed by means of a dynamic seal, the sealing element 11 of which is provided in the form of a primary seal or material seal. The sealing element 11 is annular and has an inner surface 12 which bears on a conical outer surface 13 of the piston 8.

The piston 8 has a slot 14 in the manner of an elongated hole, in which a pin 15 of a compression device 16 is guided. The compression device 16 is designed in the manner of a hollow-drilled shaft.

The sealing element 11 is constructed from a partial flow of the bulk material 4, but also contains a small amount of additive and / or bulk material-different elements.
In the exemplary embodiment shown, the bulk material 4 to be processed is first fed from a feed material feeder 17 to a flow divider or a flow divider device 18. For example, 90% of the bulk material to be conveyed is fed directly to the feed device 5 via filter, sieving, crushing, rolling or grinding processes, and the remaining 10% of the material, according to the same or similar preprocessing steps, is fed in Fig. 2 sealing element feed unit 19 shown.

The sealing element feed unit 19 can be designed as a "side feeder" or "top feeder". A so-called “side feeder” is shown, in which the bulk material to be conveyed is introduced into the working space 2 of the conveying device 1 via a side inlet. As from the Fig. 1 it can be seen that the sealing element feed unit 19 can optionally be fed with an additive via an additive strand 20 and mixed with the partial stream 26 of the bulk material stream.

The lower end of the cylinder 3 has an outlet which projects into a further processing chamber 23. This outlet is closed by a closure component 21, so that the corresponding pressure for further processing can be built up in the working space 2 of the cylinder 3.

In Fig. 3 the filling of a sealing space to form the sealing element 11 of the dynamic seal is shown as a primary seal or material seal. While the compacting device 16 moves in the opposite direction to the processing chamber 23, the piston 8 is held back by friction of the sealing element 11 against the inner wall of the working space 2. This opens a gap 4, the volume of which is approximately the volume of the sealing element worn away by wear corresponds. This volume is then replenished in the area of the sealing element feed unit 19 and thus regenerated.

In the next step, as in Fig. 4 shown, the compression device 16 and the piston 8 move towards each other due to the increasing pressure in the working space 2, which on the one hand leads to a compression of the material of the sealing element 11 and on the other hand to a radial outward displacement of the material, this radially through the outer wall of the conveying device 1 here the inner surface 9 of the cylinder 3 is limited. In any case, a sealing gap 10 between the movable conveyor element and conveyor device 1 is closed by the sealing element 11.

In Fig. 5 it becomes visible how, in a subsequent step, the bulk material 4 is compressed from the bulk material flow to be conveyed in the working space 2 of the cylinder 3 and a pressure corresponding to the pressure space 23 is built up, which can only be realized by the presence of the sealing element 11.
As soon as the defined pressure has been reached, the working space 2 of the conveying device 1 can be opened via an auxiliary piston 22 and an in Fig. 6 shown discharge of the bulk material 4 is made possible.

Essentially, however, the bulk material 4 is not compressed, but only the working space 2 is brought to the pressure as it prevails in the further processing chamber 23. After the compression phase Fig. 5 and the ejection phase Fig. 6 the working space 2 of the cylinder 3 is closed again with respect to the further processing chamber 23. By retracting the piston 8, the working space 2 becomes as in Fig. 7 shown evacuated again.

In Fig. 8 A second embodiment 24 of a conveyor system 1 according to the invention is shown. Here two conveyor systems 1 according to the invention are used perpendicular to each other. Both conveyor systems 1 have an outlet opening which opens into a further processing chamber 23, which can be part of a pressure vessel, for example. In the case of two combined conveyor systems 1, the ejection process advantageously takes place in one cylinder when the compression phase is in progress in the other cylinder. In order to feed the To achieve further processing chamber 23, several such conveyor systems can also be combined with one another.

In Fig. 9 the process of conveying the bulk material into the further processing space 23 is shown again schematically. In a feed material feeder, the bulk material stream to be conveyed is divided into a main stream and a partial stream 26 at a conveying stream dividing device 18. In addition, additives from an additive strand 20 can be added to produce a sealing element from a material seal.
While the fuel preparation takes place in a step 25, as an alternative to the methods already described, the dynamic seal can be produced as a primary or secondary seal in a separate step 27. For example, a material seal can be made in the form of a disc or plug. This can be done either by adding additives or by pure compression. Alternatively, the partial flow 26 can also be used to produce a secondary seal which is filled into a shaping elastic sealing element. An additional quality check 28 can be provided to check the sealing effect of the primary or secondary seal. The further processing of prepared bulk material from the fuel preparation 25 and from the partial flow 26 with or without additives then takes place in a step 29 in the further processing chamber, the dynamic seal being able to be produced in the processing process itself or being introduced into the conveying process as a finished seal.

The advantage of the conveying device according to the invention and the conveying method according to the invention is that the energy required to seal the pressure chamber from the ambient pressure can be significantly reduced compared to compacting or continuously compacting conveying devices, since the entire bulk material flow or conveying flow does not have to be compressed.
The combination of several conveyor systems can nevertheless achieve an almost continuous loading of a further processing chamber 23 or a pressure chamber.

Reference list

1

Device for conveying bulk goods, conveying device

2nd

working space

3rd

cylinder

4th

Bulk goods

5

Feeding device

6

Auger

7

Longitudinal axis

8th

piston

9

Inner surface of the cylinder

10th

Sealing gap

11

Sealing element

12th

Inner surface of the sealing element

13

Outer surface of the piston

14

slot

15

Cones

16

Compression device

17th

Starting material feeder

18th

Flow dividing device

19th

Sealing element feed unit

20th

Additive strand

21

Closure component

22

Auxiliary piston

23

Processing chamber, pressure room

24th

Conveyor system

25th

Fuel preparation

26

Partial flow of the bulk material flow

27

Manufacturing of sealing elements

28

Quality inspection

29

Manufacturing process

Claims (12)

1. A device (1) for conveying bulk material, comprising

   - a movable conveying member

   - and a outer wall which is stationary in relation to the conveying member;

   - wherein

   - the device is connected to a further processing chamber (23) for receiving and further processing the bulk material (4), and

   - a dynamic seal is deployed for providing a seal with respect to the pressure difference between the further processing chamber (23) and areas situated upstream in the process, characterized in that a sealing element (11) of the dynamic seal is made from a sealant in the form of a material pattern or material seal, which may be regenerated during the operation of the conveying device, the sealing element being provided from the partial flow of the bulk material to be conveyed or from a partial flow of the bulk material to be conveyed and a separate sealant supply.
2. The device (1) according to Claim 1, characterized in that the sealing element (11) of the dynamic seal is provided as a primary or secondary seal.
3. The device (1) according to Claim 1 or 2, characterized in that the dynamic seal is provided as a translational or rotational seal on the movable conveying member or the stationary outer wall of the conveying device (1).
4. The device (1) according to one of the preceding claims, characterized in that the conveying device (1) includes a cylinder (3), and a piston (8), which moves back and forth in the cylinder (3), is provided as the conveying member.
5. The device (1) according to one of the preceding claims, characterized in that the sealing element (11) of the dynamic seal in the form of the material pattern or material seal is molded as a sealing jacket.
6. The device (1) according to Claim 5, characterized in that the sealing jacket has a preferably low wall thickness, which, on the one hand, is great enough to withstand the occurring forces and pressures during operation and, on the other hand, is so low that only a small mass and/or a small volume of the material pattern or material seal has to be compressed.
7. The device (1) according to one of Claims 1 through 3, characterized in that the conveying device (1) includes a drum or a cylinder, and the conveying member is provided as a cell wheel rotating in the drum or the cylinder.
8. The device (1) according to one of the preceding claims, characterized in that the sealing element (11) of the dynamic seal in the form of the material pattern or material seal contains one or multiple additive(s).
9. The device (1) according to one of Claims 1 through 6, characterized in that the sealing element (11) of the dynamic seal form of the regenerative material pattern or material seal is made from a paste-like or liquid material.
10. A method for conveying bulk materials to a further processing chamber (23) or a pressurized space, in which a sealing element (11) of a dynamic seal is formed from a partial flow (26) of the bulk material to be conveyed or from a partial flow of the bulk material to be conveyed and a separate sealant flow for the purpose of sealing a conveying device (1) with respect to the ambient pressure or bulk material stock.
11. The method according to Claim 10, in which the sealant is continuously or discontinuously conveyed from the partial flow (26) or from the partial flow and sealant flow into a working chamber (2) of the conveying device (1), which may be used for compression, and/or is compressed therein, with the aid of a movable conveying member.
12. The method according to one of Claims 10 or 11, in which the sealant for the sealing element (11) of the dynamic seal is added to the bulk material flow during the operation of the conveying device (1) and is processed together with the bulk material flow in the pressure or further processing chamber (23).

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