Arrangement for transporting highly dispersed powders, and method of filling and emptying the same

Abstract

A container with a top edge, a bottom edge and a rear side provided with a door, containing an inliner, wherein the inliner comprises at least two layers located one above the other, an inner layer consisting of uncoated, air-permeable fabric and an outer layer being coated so as to be dust-tight and to provide a moisture barrier, these layers being connected to one another by a special seam such that dust-free venting of the receptacle is possible only through this seam, the inliner being fastened in a reversible manner in the container and having at least one filling opening and an emptying opening.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a container for transporting highly dispersed powders and to a method of filling and emptying the same.

2. Background Art

Handling pourable materials of extremely low bulk density gives rise to problems in various respects. Both the manufacturers and the end users are faced with the fact that such materials swirl up dust even in the case of extremely low levels of air convection. The creation of dust must be avoided in order to protect staff who handle the materials against potential health risks caused by breathing in the dust. Furthermore, the low bulk density causes increased transportation costs because the ratio of receptacle weight to filling weight is high and a correspondingly large amount of packaging material is required.

EP-A 0 773 159 (U.S. Pat. No. 5,682,929) discloses a method of filling and emptying a container with pourable material of low bulk density, multiple times. The fabric containers disclosed therein, the so-called “Big Bag” or “Super Bag,” have a filling capacity of 90 to 350 kg. The fabric container consists of a flexible, air-permeable fabric, preferably a plastic fabric with one or more layers and with at least one access opening. These fabric containers are filled by means of vacuum-filling systems. In this case, the fabric container is subjected to the action of negative pressure and the material is sucked through the open access opening into the fabric container until a predetermined filling weight has been reached. The gas here is distributed over the entire surface of the fabric container. During filling, the material is compacted in a reversible manner without its structure being destroyed in the process, in a manner similar to being filled into sacks.

The abovementioned receptacles, however, have a series of disadvantages, which are partially eliminated in the large flexible receptacles disclosed in EP 0982238 A. These flexible receptacles are characterized in that they comprise at least two layers located one above the other, an inner layer consisting of an uncoated, air-permeable fabric and an outer layer being coated so as to be dust-tight and to provide a moisture barrier, these layers being connected to one another by a special seam such that venting of the receptacle is possible only through this seam.

These large flexible receptacles are indeed impermeable to moisture and allow high levels of stability and dust-tightness, but they are limited in terms of the filling quantity. It is also desirable for large receptacles to be configured such that filling and emptying can be accelerated and precisely apportioned.

SUMMARY OF THE INVENTION

Disadvantages of prior art contained are improved upon by a container with a top edge, a bottom edge and a rear side provided with a door, the container containing an inliner, wherein the inliner comprises at least two layers located one above the other, an inner layer consisting of uncoated, air-permeable fabric and an outer layer being coated so as to be dust-tight and to provide a moisture barrier, and these layers being connected to one another by a special seam such that dust-free venting of the receptacle is possible only through this seam, the inliner being fastened in a reversible manner in the container and having at least one filling opening and an emptying opening.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates one embodiment of an inliner of the present invention;

FIG. 2 illustrates one embodiment of a filling grid for the rear door opening of the container;

FIG. 3 illustrates one mode of filling the container with a fine powder; and

FIG. 4 illustrates a discharge device useful in one embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

The container is preferably a standard transporting container which is commonly used throughout the world. The inliner corresponds, in terms of construction, to the construction of the large receptacle which is described in EP 0982238 A, although the inliner is configured such that it completely fills the interior of a standard container. The inliner is preferably configured such that the seams of the inliner which are described in EP 0982238 A are located in the longitudinal direction of the container, on the top and bottom edges of the latter. The filling opening of the inliner is preferably in the form of a filling connector comprising a fabric hose which is fixed to the inliner. The fabric hose preferably consists of the same material as the inliner. The filling connector preferably has a length of less than 100 cm and preferably a diameter of between 5 and 40 cm. The filling opening and the emptying opening are preferably located one beside the other on the bottom edge of the rear side of the container. The emptying opening preferably corresponds, in terms of shape and size, to the filling opening.

In order for the inliner to be suspended in a dimensionally stable manner in the container during filling and emptying, the inliner is preferably fastened in a reversible manner, by means of a plurality of fixing loops, on the eyelets and fastening crosspieces in the interior of the container (FIG. 1). There are preferably 1 to 10 fixing loops on each longitudinal edge of the inliner. Each fixing loop is preferably fastened on the inliner by an overlooked seam. Since standard containers have different fastening points, usually eyelets or crosspieces, in the interior, but the inliner has standard fixed loops, flexibility for fitting in the fixing loops of the inliner is preferably achieved in that a plurality of eyelets (crosspieces) of the container are connected to a strip and this strip can run through the fixing loops.

By virtue of the inliner being vented over its entire inner surface, reversible compaction of the high air content solids is made possible during the filling operation, this compaction not changing the product properties. It is only by this means that a high degree of filling of the container/inliner can be achieved.

The invention also relates to a method of filling a container according to the invention. The filling method is defined in that, in the container according to the invention, the inliner is filled with contents via the filling opening, by means of dense-stream conveying, until a predetermined filling weight has been reached, the dense-stream conveying system is removed and the filling opening is then closed.

During filling, use is made of dense-stream conveying which applies the necessary compacting pressure, compaction preferably taking place by means of diaphragm pumps.

In contrast to the method which is known from EP-A 0 773 159, the invention does not use negative pressure; rather, the product is introduced into the inliner with pressure, in which case the dissipation of pressure (air) does not take place via a separate opening; rather, the inliner is vented preferably over the entire surface of the inner fabric layer of the inliner into an intermediate region between the inner fabric layer and outer fabric layer, and the rest of the venting operation in the outward direction takes place from this intermediate region via the seams of the inliner.

During filling of the container, a filling grid (FIG. 2) is preferably inserted into the rear-side door opening of the container. This avoids the inliner bulging out there during filling and ensures that the doors of the container are easily closed once the inliner has been filled. It is preferable, for this purpose, for the filling grid (1) to be fitted, in the first instance, from above into the ISO blocks (3) of the container (2). Two side frames (4) with fastening hooks (5) are inserted on the left and right into the filling grid (1) hanging on the container (2). The two fastening hooks (5) are then fitted into the ISO blocks (3) at the bottom left and right and pushed into the ISO blocks until they come to a stop. The entire filling-grid frame is fixed to the container. This can take place, for example, by means of two hand wheels (6).

FIG. 3 shows, by way of example, the operation of filling the inliner in the container. The filling connector (7) of the conveying unit is connected to a feed vessel containing the high air content solids, and is pushed into the filling hose (8) to the extent where it projects approximately 10 cm into the inliner (9). The filling connector (7) is connected in a dust-tight manner to the filling hose (8) and thus to the filling opening of the inliner. Filling takes place via the filling connector, the contents being conveyed into the filling connector by means of a pressurized conveying system, preferably by means of a controllable diaphragm pump. In addition, fluidizing air is introduced into the filling connector (7) to the extent where the flowability of the contents is maintained without, at the same time, excessive quantities of air being brought into the inliner.

If the desired (i.e. usually maximum) filling weight has been achieved, the filling connector is uncoupled and the filling opening of the inliner is closed. The end point of the filling operation is determined, for example, via a pressure sensor, the increase in pressure determining the end point of the filling operation and the latter being terminated automatically. Quantities below the maximum filling weight may be determined, for example, via the filling period or via a platform weigher on which the entire unit is standing.

The invention also relates to a method of emptying a filled container according to the invention. This method is defined in that the emptying opening of the inliner of the filled container is connected to a discharge arrangement and a suction device and opened and the contents are sucked out of the inliner with the aid of the suction device. The container is preferably emptied by means of a discharge device (FIG. 4), which can be fitted to the standard container.

The discharge unit is preferably constructed such that it can be fixed in the ISO blocks of the container. It preferably comprises a preferably conical emptying tube (11) and a supporting cage (12). The emptying tube (11) is pushed into the emptying opening (14) of the inliner and connected in a dust-tight manner thereto for dust-free emptying purposes. The supporting cage (12) can be pushed in a variable manner into the emptying opening (14) of the inliner.

The supporting cage (12) ensures, during emptying, that, in the case of a suction-action conveying system, the emptying hose of the inliner is not compressed. The supporting cage preferably contains fluidizing openings through which it is possible to blow in preferably air or inert gases for loosening the material in the region of the emptying opening of the inliner (DL), in order to re-establish the flowability of the solids for the emptying operation to the necessary extent.

During emptying, use is preferably made of a discharge device with a pressure-pulse generator (13), preferably with a control unit, the pressure-pulse generator, during emptying, ensuring friction-free product discharge of the material by the flowability of the material being improved via pressure pulses. The control unit is, for example, a pneumatic or electric device by means of which the frequency of the discharge-assisting pressure pulses can be adjusted, i.e. set to requirements, e.g. initiating the compressed-air gun every 5 or 10 minutes.

In order to render the material capable of flowing, it is preferred for the filled container to be moved into an oblique position, preferably >30° from the horizontal.

The container and method according to the present invention are suitable, in particular, for transporting highly dispersed silicic acid.

While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.

Claims

1. A container with a top edge, a bottom edge and a rear side provided with a door, containing an inliner, wherein the inliner comprises at least two layers located one above the other, an inner layer of uncoated, air-permeable fabric, and an outer layer being coated so as to be dust-tight and to provide a moisture barrier, these layers being connected to one another by a seam such that dust-free venting of the receptacle is possible only through this seam, the inliner being fastened in a reversible manner in the container and having at least one filling opening and at least one emptying opening.

2. The container of claim 1, wherein the filling opening and the emptying opening are located adjacent each other on the bottom edge of the rear side of the container.

3. The container of claim 1, wherein the inliner is configured such that the seams of the inliner are located in the longitudinal direction of the container, on the top and bottom edges of the container.

4. The container of claim 1, wherein the filling opening of the inliner is in the form of a filling connector comprising a fabric hose which is fixed to the inliner.

5. The container of claim 1, wherein the emptying opening is similar, in terms of shape and size, to the filling opening.

6. A method of filling and emptying a container of claim 1, wherein, the inliner is filled with contents via the filling opening by means of dense-stream conveying until a predetermined filling weight has been reached, the dense-stream conveying system is removed, and the filling opening is closed.

7. The method of claim 6, wherein filling takes place by means of a diaphragm pump.

8. The method of claim 6, wherein, a filling grid is inserted into the rear-side door opening of the container.

9. A method of emptying a filled container of claim 1, wherein the emptying opening of the inliner of the filled container is connected to a discharge arrangement and a suction device and opened, and the contents are sucked out of the inliner with the aid of the suction device.

10. The method of claim 9, wherein the discharge device comprises a pressure-pulse generator which ensures friction-free product discharge of the material during emptying by the flowability of the material being increased via pressure pulses.

11. The method of claim 9, wherein the discharge device is fitted to the container.

12. The method of claim 9, wherein the container is located in an oblique position during emptying.

13. The method of claim 12, wherein said oblique position is greater than 30° from horizontal.