DEVICE AND METHOD FOR CONVEYING BULK MATERIAL INTO A PRESSURE CHAMBER

Abstract

A device for continually conveying dust-like or granular bulk materials into a pressure Chamber, having an inlet opening through which the bulk material is supplied or discharged from a bulk material storage, a housing which is arranged along a rotational axis, a conveying region which adjoins the inlet opening, and a shaft which rotates in the housing and which has a conveyor arranged on the circumference. The rotational axis, the housing and the shaft are arranged vertically, and a seal in the form of a regeneratable material seal stopper. The seal sealing the pressure chamber, is arranged in the conveyor region between the pressure chamber and the inlet opening. The housing has a polygon, a cannelure, or at least one helically running groove on the housing inner wall, and the orientation of the polygon, the cannelure, or the groove runs substantially perpendicularly to the two-dimensional orientation of the conveyor.

Claims

1. A device for continuously conveying dust-like or granular bulk materials into a pressure chamber, the device comprising: an inlet opening through which the bulk material is supplied or discharged from a bulk material storage; a housing that is arranged along a rotational axis; a conveying region that adjoins the inlet opening, the conveying region comprising a venting region, a compacting region, and a sealing region; and a shaft adapted to rotate in the housing and which comprises a conveyor arranged on a circumference of the shaft, wherein the rotational axis, the housing, and the shaft are arranged vertically, and a seal in a form of a regenerable seal stopper is arranged in the conveying region between the pressure chamber and the inlet opening, the seal sealing the pressure chamber, and wherein the housing has a polygon, fluting, or at least one helically running groove on an inner wall, and an orientation of the polygon, fluting, or the groove runs substantially perpendicular to the two-dimensional orientation of the conveyor.

2. The device according to claim 1, wherein a lead angle of the fluting, the polygon, or the at least one groove with respect to the rotational axis is provided decreasing from the inlet opening in a direction of the outlet opening.

3. The device according to claim 1, wherein the fluting, the polygon, or the at least one groove is provided parallel or substantially parallel to the rotational axis at least in partial a region of the conveying device.

4. The device according to claim 1, wherein the shaft ends in a shaft journal free of the conveyor in the sealing region of the conveying device.

5. The device according to claim 1, wherein the regenerable material seal stopper is provided in an annular gap between the shaft and/or between the shaft journal and the housing.

6. The device according to claim 1, wherein the conveyor of the shaft is arranged on the circumference is provided as conveying vanes in the venting region.

7. The device according to claim 1, wherein the shaft with its conveyor arranged on the circumference is provided in the compacting region as a compacting screw, cylindrical spiral, or Archimedean spiral with a volume decreasing in the conveying direction per pitch length.

8. The device according to claim 1, wherein the outlet opening of the conveying device is provided on the circumference on the housing.

9. The device according to claim 4, wherein the end of the shaft or of the shaft journal facing the pressure chamber, has a plate-shaped or conical enlargement.

10. The device according to claim 9, wherein, to change a height of the outlet opening of the conveying device, the enlargement and the housing or a part of the housing are disposed movable relative to each other.

11. A conveyor system with a device for conveying dust-like or granular bulk materials into a pressure chamber according to claim 1, wherein the conveyor system comprises a first container which contains a bulk material storage.

12. A method for conveying dust-like or granular bulk material into a pressure chamber, comprising: discharging a dust-like or granular bulk material into a conveying device according to claim 1; venting and conveying the bulk material stream to be processed in the conveying device; compacting the conveyed bulk material to form a material seal stopper which withstands the pressure difference between bulk material feed and pressure chamber; and conveying the material seal stopper up to an outlet opening of the conveying device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

[0023] FIG. 1 shows a sectional view through a conveying device of the invention;

[0024] FIG. 2 shows a sectional view through an embodiment of a conveying device of the invention with a modified geometry of the housing and the conveyor of the shaft in the compacting region;

[0025] FIG. 3 shows a sectional through an embodiment of the conveying device of the invention; and

[0026] FIG. 4 shows a sectional view through an embodiment variant of the conveying device of the invention.

DETAILED DESCRIPTION

[0027] FIG. 1 shows a conveying device for conveying lumpy, granular, or powdered bulk material from a bulk material storage to a pressure chamber. In the present exemplary embodiment, coal is removed from a bulk material container (not shown) and fed through an inlet opening 14 to a conveying device. The conveying device comprises a vertically arranged shaft 1, which is connected via a drive train 12 to a motor M, located outside the conveying device, and is driven by the same. This results in the conveying direction of the piece goods in the direction of gravity from the top downwards. This promotes the uniform filling of the conveying device. Furthermore, the conveying device comprises a rotationally symmetrical housing 11, 6, 7, 9, which surrounds shaft 1. Housing 11, 6, 7, 9, which has both cylindrical and conical regions, extends from an inlet opening 14 to an outlet opening 15.

[0028] Shaft 1 accordingly rotates about a vertical rotational axis 13, which at the same time represents the rotational axis of housing 11, 6, 7, 9.

[0029] In the present exemplary embodiment, shaft 1 is mounted in the conveying device in an unsupported manner. This means that it is mounted only on one side in the conveying device and accordingly no bearings are provided on its end facing the pressure chamber. In addition, shaft 1 can be disposed movably in the conveying device. Furthermore, shaft 1 has a conveyor 2, which are arranged on it on the circumference. The bulk material is accordingly transported through the conveying device in a gap between shaft 1 and housing 11, 6, 7, 9.

[0030] The conveying path of the conveying device can be divided over the distance from inlet opening 14 to outlet opening 15 into a plurality of conveying regions which are divided into an inlet region h0, venting region h1, compacting region h2, and sealing region h3 in the conveying direction. Inlet region 11 is designed in such a way that bridge formation of the bulk material is reliably avoided. Depending on the bulk material to be conveyed, a defined diameter or a defined clearance between the housing inner wall and drive train 12 results.

[0031] Depending on the conveying region, the conveyor 2 are adapted with regard to their shape and orientation to the respective degree of conveying and compaction of the bulk material. In venting region h1, the conveyor 2 is provided in the form of blades or vanes which detect the bulk material and feed it to the subsequent compacting region h2. Conveyor 2 enable the bulk material to be adequately vented by exerting only moderate force on it and thus counteracting over-compaction in the venting region.

[0032] In the subsequent compression region h2, conveyor 2 is arranged on shaft 1 in blade form in the shape of a helix so that a compacting screw 3 in the form of a full-blade screw is produced. The gap between the shaft and the housing inner wall is accordingly reduced in height to the pitch of the helix. In order to effect further compacting of the bulk material, this volume can be further reduced, for example, by reducing the pitch of the helix or tapering the housing inner diameter in the direction of outlet opening 15.

[0033] Compacting screw 3 exerts a massive force on the bulk material to be conveyed. Within compacting region h2, the bulk density of the material is drastically increased, so that it begins to compact. Due to the increasing material compaction, the friction forces increase as well. In order to prevent the compacting bulk material from rotating with shaft 1, the housing wall is fluted. This means that at least one groove 8 is provided in the inwardly directed housing wall, which groove also extends helically from the top downwards. In this case, groove 8 describes a spiral shape which opposes the pitch of compacting screw 3. The fluting or groove 8 is thereby oriented such that it is always at the ideal angle to the blade-shaped conveyor of shaft 1. In this case, the blade-shaped conveyor pushes the compacted bulk material in the conveying direction downwards along groove 8 of housing 7. The compacted bulk material is thereby supported in the fluting and is thus effectively prevented from co-rotating.

[0034] In sealing region h3 of the conveying device, in contrast, shaft 1 has a smooth surface free of the conveyor. In this region h3, a groove or fluting is also not provided in the housing inner wall of housing 9 so that an annular gap is produced as an interspace between shaft journal 4 and the housing inner wall.

[0035] In this annular gap, the compacted bulk material is pressed coming out of compacting region h2 into sealing region h3. Because shaft 1 or shaft journal 4 has, at its end facing the pressure chamber, an enlargement 5 which closes the conveying device in the axial direction, a material seal stopper starts to form at the lower end of sealing region h3. Enlargement 5, which rotates with shaft 1, during operation accordingly serves as a deflection plate and as a securing device for the material seal stopper. The material seal stopper itself is repeatedly filled from above with new compacted material and passes through sealing region h3. In the lower region of housing 9, outlet opening 15 is arranged on the circumference. This can be closed by a sleeve 10, which is disposed in the region of the outlet opening of housing 9, or can be varied in its size. The arrows in the drawing accordingly indicate the direction of movement of sleeve 10.

[0036] In the idle state of the conveying device, sleeve 10 completely closes outlet opening 15. This state is shown with dashed lines in the drawing. During start-up, sleeve 10 continues to remain in the closed position and helps to build up the material seal stopper. Once the material seal stopper has reached the required strength after a certain conveying time so that it can withstand the pressure difference between the pressure chamber and the ambient pressure at inlet opening 14, sleeve 10 is pulled upward and releases outlet opening 15 of the conveying device. The material of the material seal stopper is then dispersed at enlargement 5 of shaft 1, which then serves as a deflection plate, and leaves the conveying device as a loose material through outlet opening 15 into the pressure chamber. Intermediate positions of sleeve 10 are possible as a function of the desired conveying capacity. When the conveying device is stopped, the closing of sleeve 10 is then carried out accordingly.

[0037] The second variant of the conveying device of the invention according to FIG. 2 has a geometry of grooves 8 provided on the inner housing wall, said geometry being modified compared with the first embodiment. Grooves 8 also extend in the form of a spiral but have a different inclination or pitch, in contrast to the first embodiment in FIG. 1. Grooves 8 here also describe a spiral shape which opposes the pitch of compacting screw 3.

[0038] In the third variant of the conveying device of the invention in FIG. 3, grooves 8 in contrast have a varying lead angle. With respect to rotational axis 13 or a longitudinal axis of compacting screw 3, the lead angle of grooves 8 decreases coming from inlet opening 14 in the direction of outlet opening 15. Whereas grooves 8 have the steepest lead angle at the upper end, facing inlet opening 14, of compressing screw 3, the angle decreases in the direction of the outlet opening until the grooves extend parallel or approximately parallel to rotational axis 13 or the longitudinal axis of compacting screw 3 in the region of the outlet opening.

[0039] Furthermore, FIG. 4 shows a fourth variant of the conveying device of the invention, wherein the region of grooves 8, extending parallel or approximately parallel, is lengthened compared with the embodiment shown in FIG. 3.

[0040] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.