HIGH CONTAINMENT DISCHARGE STATION

Abstract

The invention relates to a discharging apparatus for discharging loose and in particular pulverulent material that is hazardous to health from rigid or flexible containers (12), in particular bags and barrels (13), comprising a discharge chamber (2) which has a discharge opening (5) for discharging the material after removal from a container (12) and which additionally has an insertion opening (3) for at least partial insertion of a container (12) into the discharge chamber (2). According to the invention, the discharge chamber (2) has a ventilation opening (4) which is arranged at a side of the discharge chamber (2) opposite the insertion opening (3) and which is connected to pump means (10) in such a way that an air stream can be generated inside the discharge chamber (2), which causes a laminar air flow starting from the insertion opening (3) and leading in the direction of the ventilation opening (4).

Claims

1. An unloading device for unloading loose material hazardous to health from rigid or flexible containers the unloading device comprising an unloading chamber comprising a discharge opening discharging the material after removal from a container and further comprising an insertion opening for at least partial insertion of a container into the unloading chamber, wherein the unloading chamber has a ventilation opening which is disposed on a side of the unloading chamber opposite the insertion opening and which is connected to pump means in such a manner that an airflow can be generated inside the unloading chamber, the airflow causing a laminar airflow from the insertion opening in the direction of the ventilation opening, wherein a, preferably vertical, partition wall having a variable passage opening is disposed between the insertion opening and the unloading chamber inside the unloading chamber, wherein the opening is designed and dimensioned in such a manner that the containers to be emptied, insofar as they are completely received in the unloading chamber, can pass through the passage opening and is also designed in such a manner that no airtight sealing or closure is achieved by the partition wall in any state during the emptying, and wherein a nozzle arrangement is disposed in the area of the insertion opening, the nozzle arrangement being connected to pump means in such a manner that an airflow in the direction of the ventilation opening can be generated.

2. The unloading device according to claim 1, wherein the cross section of at least part of the unloading chamber increases from the insertion opening in the direction of the ventilation opening.

3. The unloading device according to claim 2, wherein a closure device for the reversible opening and closing of the insertion opening is assigned to the insertion opening.

4. The unloading device according to claim 1, wherein a seal device for the sealing contact with container surfaces is disposed in the area of the insertion opening.

5. The unloading device according to claim 1, wherein a container conveyor or transport means is disposed inside the unloading chamber.

6. A method for unloading loose material hazardous to health from rigid or flexible containers, the method comprising the at least partial insertion of the container into an unloading chamber via an insertion opening of the unloading chamber and the emptying of the container and the discharge of the material via a discharge opening of the unloading chamber, wherein, at least during the emptying of the container, an airflow is generated by a ventilation opening which is disposed on a side of the unloading chamber opposite the insertion opening and by pump means assigned thereto, the airflow causing a laminar airflow from the insertion opening in the direction of the ventilation opening, wherein before the container is emptied, the container passes through a partition wall having a variable passage opening between the insertion opening and the unloading chamber inside the unloading chamber, wherein the opening is designed and dimensioned in such a manner that the containers to be emptied, insofar as they are completely received in the unloading chamber, can pass through the passage opening and wherein the variable passage opening is designed in such a manner that no airtight sealing or closure is achieved by the partition wall in any state during the emptying and wherein a nozzle arrangement is disposed in the area of the insertion opening, the nozzle arrangement being connected to pump means in such a manner that an airflow in the direction of the ventilation opening is generated.

7. The method according to claim 6, wherein an airflow of 0.6 m/s to 0.8 m/s is generated in the area of the insertion opening.

8. The method according to claim 6, wherein at least part of the cross section of the unloading chamber increases from the insertion opening in the direction of the ventilation opening, the speed of the airflow in the area of the discharge opening thus being reduced to approximately ⅓ to ⅙ of the speed in the area of the insertion opening.

9. The method according to claim 6, wherein a volume flow is extracted through the ventilation opening (4), the volume flow being proportional to the size or surface of the insertion opening.

10. The method according to claim 6, wherein the insertion opening is opened by means of a closure device for the reversible opening and closing of the insertion opening in order to at least partially insert the container.

11. The method according to claim 6, wherein a seal device is disposed in the area of the insertion opening, the seal device coming into sealing contact with a container surface, before a container is emptied.

12. (canceled)

13. (canceled)

14. (canceled)

15. (canceled)

16. The unloading device according to claim 1, wherein the loose material comprises powdery material and the containers comprise bags or drums.

17. The unloading device according to claim 1, wherein the partition wall is a vertical partition wall.

18. The method according to claim 6, wherein the loose material is powdery material, and wherein the containers comprise bags or drums.

19. The method according to claim 6, wherein the partition wall is a vertical partition wall.

20. The method according to claim 8, wherein the speed of the airflow is reduced to 0.1 m/s to 0.3 m/s.

21. The method according to claim 9, wherein the volume flow is 200 m.sup.3/h to 800 m.sup.3/h.

22. The method according to claim 10, wherein the insertion opening remains open during emptying of the container.

23. The method according to claim 11, wherein the container surface is a drum surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Further advantages, features and details of the invention are apparent from the following description of preferred exemplary embodiments and from the drawings.

[0035] In the drawings,

[0036] FIG. 1 shows a schematic illustration of a generic unloading device;

[0037] FIG. 2 shows a schematized illustration of a generic unloading device;

[0038] FIG. 3 shows a schematized illustration of a third embodiment of an unloading device realized according to the idea of the invention for performing the method according to the invention.

DETAILED DESCRIPTION

[0039] FIG. 1 shows an unloading device 1 which has an unloading chamber 2 opening into an insertion opening 3 on one side and having a ventilation opening 4 on the opposite side. For example, insertion opening 3 can have a surface A.sub.1 of 0.1 m.sup.2 to 0.4 m.sup.2, preferably 0.2 m.sup.2 to 0.3 m.sup.2. Ventilation opening 4 can preferably have a surface of 0.4 m.sup.2 to 0.8 m.sup.2, wherein a surface of 0.6 m.sup.2 to 0.8 m.sup.2 is preferred for unloading devices 1 which work with drums as containers, whereas a surface of 0.4 m.sup.2 to 0.6 m.sup.2 is preferred for unloading devices 1 which work with bags as containers.

[0040] Furthermore, unloading chamber 2 of unloading device 1 comprises a discharge opening 5 by means of which the material to be unloaded or to be emptied can be discharged. For example, a mechanical crushing device can be disposed in the area of discharge opening 5 in order to break up caked material. The crushing device can be designed as a lump breaker (not shown in FIG. 1). A transport length L of the unloading device is preferably defined between the center of insertion opening 3 and the center of discharge opening 5. Further preferably, a particularly good laminar flow and particularly low contamination of the environment is achieved if the ratio of surface A.sub.1 of insertion opening 3 to transport length L is smaller than 0.3 m, preferably between 0.08 m and 0.22 m, in particular between 0.10 m and 0.20 m.

[0041] Transport length L can preferably be chosen as long as possible, because the treatment of the containers taking place in the area of discharge opening 5 may potentially cause turbulence in the airflow.

[0042] Unloading chamber 2 of unloading device 1 also comprises an outlet opening 6 via which emptied containers, i.e., bags or inner liners of drums, can be removed from unloading device 1 after appropriate sealing, for example. In the example of FIG. 1, ventilation opening 4 is followed by a pre-filter 7 and a double HEPA filter 8, ventilation opening 4 being connected to pump means 10 via filters 7, 8 and a pipeline 9. Air can be sucked in by means of pump means 10, a laminar airflow directed from insertion opening 3 in the direction of ventilation opening 4 thus being created inside unloading chamber 2.

[0043] Pump means 10 are preferably connected to control means which are configured to change or regulate the airflow. The control means can ensure that, depending on the material to be unloaded, for example depending on the particle volume, the particle density and/or the particle weight, the transport of particles is performed in an optimal manner and, in particular, that a correspondingly optimal airflow is generated. The control means can be designed in such a manner that the airflow is specified or set by a user. Alternatively, an automatic identification of the material and an automatic control of pump means 10 by the control means can also be provided. Overall, a reduction of the airflow can be provided if a material has a low density or light particles.

[0044] Pre-filter 7 can be realized as a cloth, for example, which contacts a wall surface of unloading chamber 2 and which is clamped into a frame (not shown) or otherwise fixed to the frame. Pre-filter 7 can preferably be changed inside unloading chamber 2, in particular by taking off the frame and removing the cloth. Used and potentially clogged or blocked pre-filter 7 can be safely disposed of through outlet opening 6.

[0045] To generate and maintain a laminar airflow depending on the states of filters 7, 8 and the performance of pump means 10, unloading device 1 can also comprise one or several pressure sensor means 24 which each measure the air pressure at specified points of unloading device 1. In the example of FIG. 1, three pressure sensor means 24 measuring the respective pressure or air pressure can be provided in the area of pre-filter 7 and filters 8. For example, the pressure difference can also be determined via respective filters 7, 8 by means of corresponding evaluation means (not shown). Said pressure differences can in turn be used to determine the state of the filters and the need for a filter change.

[0046] The cross section of part of unloading chamber 2 increases from insertion opening 3 in the direction of ventilation opening 4 or in the direction of discharge opening 5. For example, the cross section of unloading chamber 2 has a first cross section A.sub.1 in the area of insertion opening 3, first cross section A.sub.1 increasing up to a maximal cross section A.sub.max in the area of discharge opening 5. This has the effect that a laminar airflow is created which has a greater flow speed in the area of insertion opening 3 than in the area of discharge opening 5 or ventilation opening 4, for example.

[0047] Bags of toxic material or material hazardous to health, for example, can be inserted into the inside of the unloading chamber via insertion opening 3. To this end, closure device 11 of the insertion opening can be opened. As soon as or even before such a container is inside the unloading chamber, pump means 10 can be activated, for example at the same time as closure device 11 is opened, and a laminar airflow from insertion opening 3 in the direction of ventilation opening 4 can be generated. When the container, e.g. the bag, is then opened and emptied inside the unloading chamber, the laminar airflow inside unloading chamber 2 ensures that no particles of the material escape, even if closure device 11 remains temporarily or completely open during the emptying or unloading of the container. A particularly high throughput of containers and therefore of material can thus be achieved while a particularly high level of contamination protection can be ensured.

[0048] FIG. 2 shows a modified embodiment of an unloading device 1 in which a container 12 in the form of a drum 13 can be lifted to insertion opening 3 of unloading chamber 2 and, if required, tilted by means of a lifting device (not shown). At the process stage shown in FIG. 2, closure device 11 of insertion opening 3 is already open, container 12 has already been lifted, tilted and opened and an inner package of drum 13 has already been removed by means of a container conveyor or transport means, which is shown in the form of a pulley system 14 in the example of FIG. 2. In this process, the inner package or liner 15 of container 12 has passed through a vertical partition wall 16 by means of pulley system 14, partition wall 16 having a hinged door 17 hinged on one side as variable passage opening 18. Passage opening 18 preferably extends over 30% to 50% of the height of partition wall 16. Accordingly, a laminar airflow between insertion opening 3 and ventilation opening 4 has also already been generated by means of the pump means (not shown in FIG. 2) at the process stage shown in FIG. 2, said laminar airflow then also being maintained and being maintainable because an air gap 19 is intentionally left or realized between container 12 and insertion opening 3 to allow air to continue to flow into the inside of the unloading chamber.

[0049] In addition to a first cross section A1 in the area of the insertion opening and a second, larger cross section A2 in the area of partition wall 16, the cross section of unloading device 1 has a maximal cross section Amax in the area of discharge opening 5. Enlarged cross section A2 is mainly used to generate and maintain a laminar airflow. In addition to the maintenance of the laminar airflow, largest cross section Amax also serves another purpose. After all, a maximal height of unloading chamber 2 is also achieved by the maximal cross section. Pulley system 14 can thus be realized and disposed in such a manner that the container to be emptied or to be unloaded is kept completely in the air by pulley system 14, namely in a position which is as exactly above discharge opening 5 as possible. The container, in the present case liner 15, can thus be opened, for example sliced, and emptied without shaking the container and thereby causing turbulence. Additionally, the container can be lowered onto discharge opening 5 by pulley system 14 after it has been opened or sliced, an emptying process also as dust-free as possible thus being enabled.

[0050] A handling aid, such as a disposable cord, which ensures the secure coupling of the container or liner 15 to pulley system 14, for example to a hook of pulley system 14, can be used together with pulley system 14. Preferably, said handling aid is first fixed, in particular knotted, to the container or liner 15 and is then connected to pulley system 14. The handling aid can be dimensioned and realized in such a manner that it allows safe handling of the container, in particular safe lifting of the container, as indicated, for example, in FIG. 2 by means of the position of liner 15.

[0051] Liner 15 of container 12 removed by means of pulley system 14 can thus be opened, for example sliced, and emptied without the risk of causing contamination of the environment that exceeds the relevant OEB or OEL limit value.

[0052] FIG. 3 shows a process state which essentially corresponds to the process state of FIG. 2, unloading device 1 differing from the unloading device of FIG. 2 in that no air gap 19 exists between container 12 and insertion opening 3. Instead, a seal device 20 is provided, container surface 21 coming into sealing contact with seal device 20. For example, this can be achieved in that seal device 20 is realized as an expandable seal ring to which pressure can be applied and which comprises appropriate pressure means, so that pressure can be exerted or applied to the seal ring after container 12 has been arranged accordingly, said seal ring thus pressing against container surface 21 in a sealing manner.

[0053] To ensure that the laminar airflow between insertion opening 3 and ventilation opening 4 is maintained or can be maintained in the exemplary embodiment of FIG. 3, unloading device 1 comprises a nozzle arrangement 22 which is disposed in the area of insertion opening 3 and which in turn interacts with pump means 23 and allows the generation of an airflow in the direction of ventilation opening 4. In this way, insertion opening 3 is closed and even sealed in the course of the emptying and unloading of container 12 in the exemplary embodiment of FIG. 3; however, the laminar airflow ensuring that particles of the material which may still be located or disposed in the area of insertion opening 3 are transported away from insertion opening 3 can still be maintained. Furthermore, this can ensure that no ambient air or only an insignificant amount of ambient air which has the potential of polluting or contaminating the material enters unloading device 1, in particular unloading chamber 2.

REFERENCE SIGNS

[0054] 1 unloading device [0055] 2 unloading chamber [0056] 3 insertion opening [0057] 4 ventilation opening [0058] 5 discharge opening [0059] 6 outlet opening [0060] 7 pre-filter [0061] 8 double HEPA filter [0062] 9 pipeline [0063] 10 pump means [0064] 11 closure device [0065] 12 container [0066] 13 drum [0067] 14 pulley system [0068] 15 liner [0069] 16 vertical partition wall [0070] 17 hinged door [0071] 18 passage opening [0072] 19 air gap [0073] 20 seal device [0074] 21 container surface [0075] 22 nozzle arrangement [0076] 23 pump means [0077] 24 pressure sensor means [0078] A.sub.1 first cross section [0079] A.sub.2 second cross section [0080] A.sub.max maximal cross section