DEVICE AND METHOD FOR CONVEYING BULK MATERIAL

Abstract

A device and method for conveying bulk material, said device comprising a movable conveying member and an outer wall that is stationary in relation to the conveying member, wherein the device is connected to a further processing chamber for receiving and further processing the bulk material and a dynamic seal is used which seals with respect to the differential pressure between the further processing chamber and regions lying upstream in the process. A seal element of the dynamic seal formed of a sealant in the form of a material pattern or material seal that can be regenerated during operation of the conveying device, wherein the seal element is provided from a branch flow of the bulk material to be conveyed or from a separate sealant source.

Claims

1. A device for conveying bulk material, the device comprising: a movable conveying member; an outer wall that is stationary in relation to the conveying member; a dynamic seal that seals with respect to a differential pressure between a further processing chamber and regions lying upstream in the process, the device being connected to the further processing chamber for receiving and further processing the bulk material; and a seal element of the dynamic seal comprising a sealant in a form of a material charge or material seal that is adapted to be regenerated during operation of the conveying device, the seal element being provided from a branch flow of the bulk material to be conveyed or from a separate sealant source.

2. The device according to claim 1, wherein the seal element of the dynamic seal is provided as a primary or secondary seal.

3. The device according to claim 1, wherein the dynamic seal is provided as a translatory or rotary seal on the movable conveying member or the stationary outer wall of the conveying device.

4. The device according to claim 1, wherein the conveying device comprises a cylinder and a piston, which is adapted to be moved back and forth in the cylinder and is provided as the conveying member.

5. The device according to claim 1, wherein the seal element of the dynamic seal in the form of the material charge or material seal is shaped as a sealing jacket.

6. The device according to claim 5, wherein the sealing jacket has a wall thickness as small as possible, which is large enough to maintain the arising forces and pressures during operation, and is so small that only a small mass and/or a small volume of the material charge or material seal have to be compacted.

7. The device according to claim 1, wherein the conveying device further comprises a drum or a cylinder and wherein the conveying member is provided as a rotary wheel rotating in the drum or the cylinder.

8. The device according to claim 1, wherein the seal element of the dynamic seal in the form of the material charge or material seal contains one or more additives.

9. The device according to claim 1, wherein the seal element of the dynamic seal is provided in the form of the regenerable material charge or material seal made of a pasty or liquid material.

10. A method for conveying bulk material into a further processing chamber or a pressurized chamber, the method comprising: sealing a conveying device with respect to ambient pressure or a bulk material source; and providing a seal element of a dynamic seal to seal the conveying device, the seal element being formed from a branch flow of the bulk material flow to be conveyed and/or a separate seal flow.

11. The method according to claim 10, wherein the sealant is conveyed continuously or discontinuously via a movable conveying member from the branch flow and/or the seal flow into a working space of the conveying device, which space is adapted to be used for compacting and/or compacted in it.

12. The method according to claim 10, wherein the sealant for the seal element of the dynamic seal is added to the bulk material flow during operation of the conveying device and is processed together with the bulk material flow in the pressure or further processing chamber.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] 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:

[0031] FIG. 1 shows in a schematic illustration an embodiment of a conveying device of the invention incorporated into a method of the invention;

[0032] FIG. 2 shows a sectional view along the line II through the conveying device from FIG. 1 in the region of a sealant feed unit;

[0033] FIG. 3 shows the state of the conveying device when removing a compacting device from a produced seal element and with simultaneous movement of a piston of the conveying device in the direction of a further processing chamber;

[0034] FIG. 4 shows the state of the reciprocation of the piston and the compacting device when the seal element is compacted;

[0035] FIG. 5 shows the state of the conveying device when the bulk material flow is pressurized by the piston;

[0036] FIG. 6 shows a moment of introduction of the bulk material into the further processing chamber;

[0037] FIG. 7 shows the state of evacuating the working space of the conveying device;

[0038] FIG. 8 shows an embodiment of a conveying device of the invention;

[0039] FIG. 9 shows an illustration of the method of the invention.

DETAILED DESCRIPTION

[0040] FIG. 1 shows a first embodiment of a conveying device 1 of the invention. Conveying device 1 is designed as a solids pump. It has a cylinder 3 as a stationary outer wall and a piston 8 as a movable conveying member. Stationary outer wall 3 also defines a working space 2 in which piston 8 can be moved back and forth along a longitudinal axis 7. Working space 2 can be filled with bulk material 4. Bulk material 4 is removed from a bulk material source, which comprises a feed device 5 with a conveyor screw 6.

[0041] There is a sealing gap 10 between the outer side of piston 8 and an inner side or inner surface 9 of cylinder 3. Sealing gap 10 is sealed by means of a dynamic seal, the seal element 11 of which is provided in the form of a primary seal or a material seal. Seal element 11 is made annular and has an inner surface 12 which rests against a conical outer surface 13 of piston 8.

[0042] Piston 8 has a slot 14 in the manner of a long hole in which a pin 15 of a compacting device 16 is guided. Compacting device 16 is made in the manner of a hollow-bore shaft.

[0043] Seal element 11 is constructed from a branch flow of bulk material 4 but also contains a small quantity of additive elements and/or elements different from the bulk material.

[0044] In the illustrated exemplary embodiment, bulk material 4 to be processed is first supplied from a starting material feeder 17 to a conveying flow divider or a conveying flow dividing device 18. In this regard, e.g., 90% of the bulk material to be conveyed is fed directly to feed device 5 via filter, screen, comminution, rolling, or grinding processes, and the remaining 10% of the material is fed after the same or similar preprocessing steps to a seal element feed unit 19 shown in FIG. 2.

[0045] In this case, seal 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 working space 2 of conveying device 1 via a side inlet. As is evident from FIG. 1, an additive can optionally be fed to seal element feed unit 19 via an additive branch 20 and mixed with branch flow 26 of the bulk material flow.

[0046] The lower end of cylinder 3 has an outlet which projects into a further processing chamber 23. This outlet is closed by a closing component 21, so that the corresponding pressure can be built up for further processing in working space 2 of cylinder 3.

[0047] FIG. 3 shows the filling of a sealing space for forming seal element 11 of the dynamic seal as a primary seal or a material seal. Whereas compacting device 16 moves counter to the direction of further processing chamber 23, piston 8 is retained by the friction of seal element 11 with respect to the inner wall of working space 2. As a result, a gap 10 opens whose volume corresponds approximately to the volume of the seal element removed by wear. This volume is subsequently replenished in the region of seal element feed unit 19 and thus regenerated.

[0048] In the next step, as shown in FIG. 4, compacting device 16 and piston 8 move toward one another as a result of the increasing pressure in working space 2; on the one hand, this leads to a compaction of the material of seal element 11 and, on the other hand, to a radial outward forcing of the material, the latter being radially limited by the outer wall of conveying device 1, here inner surface 9 of cylinder 3. In any case, a sealing gap 10 between the movable conveying member and conveying device 1 is closed by seal element 11.

[0049] It is evident in FIG. 5 how in a subsequent step bulk material 4 is compacted from the bulk material flow to be conveyed in working space 2 of cylinder 3 and a pressure corresponding to pressure chamber 23 is established, which can only be realized by the presence of seal element 11.

[0050] As soon as the defined pressure is reached, working space 2 of conveying device 1 can be opened, for instance, via an auxiliary piston 22, and a discharge of bulk material 4 as shown in FIG. 6 is made possible.

[0051] In this case, however, bulk material 4 is largely not compacted but only working space 2 is brought to the pressure as it prevails in further processing chamber 23. After the compression phase from FIG. 5 and the ejection phase from FIG. 6, working space 2 of cylinder 3 is again closed off from further processing chamber 23. By retracting piston 8, working space 2 is also again evacuated as shown in FIG. 7.

[0052] FIG. 8 shows an embodiment 24 of a conveyor system 1 of the invention. Here, two conveyor systems 1 of the invention are used perpendicular to one another. 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. Advantageously, in the case of two combined conveyor systems 1, the discharge process takes place in the case of the one cylinder, when the compacting phase is already in progress in the other cylinder. In order to achieve an approximately continuous feed of further processing chamber 23, a plurality of such conveyor systems can also be combined with one another.

[0053] FIG. 9 shows again schematically the process of conveying the bulk material into further processing space 23. In a starting material feed, the bulk material flow to be conveyed is divided into a main flow and a branch flow 26 at a conveying flow dividing device 18. In addition, additives from an additive branch 20 can be added for the production of a seal element in the form of a material seal.

[0054] Whereas the fuel preparation takes place in a step 25, the dynamic seal can be produced as a primary or secondary seal in a separate step 27, as an alternative to the methods already described. For example, a material seal can be produced in the form of a disk or stopper. This can be done optionally with the addition of additives or by simple compaction. Alternatively, branch flow 26 can also be used for the production of a secondary seal which is filled into a shaping elastic seal element. An additional quality test 28 can be provided for checking the sealing effect of the primary or secondary seal. The further processing of prepared bulk material from fuel preparation 25 and from branch flow 26 with or without additives is then carried out in a step 29 in the further processing chamber, wherein the dynamic seal can be produced in the processing process itself or can be introduced into the conveying process as a finished seal.

[0055] The advantage of the conveying device of the invention and of the conveying method of the invention is that the energy required to seal the pressure chamber against the ambient pressure can be considerably reduced in comparison with compacting or continuously compacting conveying devices because the entire bulk material flow or conveying flow does not need to be compacted.

[0056] An approximately continuous charging of a further processing chamber 23 or of a pressure chamber can be achieved, however, by the combination of a plurality of conveyor systems.

[0057] 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.