Method and device for contamination-free transport of pourable bulk product

The invention concerns a method for substantially contamination-free transport of pourable bulk product from a dosing unit with a lidded dosing outlet into a container with a lidded receiving inlet, wherein the dosing outlet of the dosing unit is connected with the receiving inlet of the container in a detachable manner, the dosing outlet and the receiving inlet are opened and the bulk product is transported from the dosing unit to the container via the dosing outlet of the dosing unit and the receiving inlet of the container. The invention further concerns a device suitable for using such a method for substantially contamination-free transport of pourable bulk product, having a dosing unit with a lidded dosing outlet and having a container with a lidded receiving inlet, wherein the dosing outlet of the dosing unit is connected with the receiving inlet of the container in a detachable manner. Finally, the invention concerns a facility for substantially contamination-free, gravimetric combining of individual bulk product components from several reservoirs, each having a dosing unit with a lidded dosing outlet, into a container having a lidded receiving inlet, wherein a weighing device is associated with each reservoir which acts in combination with the container at least while bulk product is being dosed coming from the respective reservoir, wherein the container travels below the dosing units of the reservoirs and can be sequentially connected, in a detachable manners to the dosing unit of the respective reservoir according to the desired mixture ratio.

When dosing fluid or pourable, primarily particulate bulk products, in particular when producing mixtures of different bulk products of such kind according to a desired mixture ratio, it is often desired that the respective bulk product does not come into contact with the surroundings during the dosing process to avoid contamination of the bulk product from the outside, but also—for example if bulk products are harmful to the health—to reliably prevent contamination of the surroundings. This applies particularly to products with increased hygiene and purity requirements, such as foodstuff, pharmaceuticals and the like. Furthermore, it must be ensured when producing mixtures of such—different—bulk products, which are, for example, stored in separate reservoirs and are to be fed to a mixing tank according to the desired recipe, that neither the dosing outlet of the respective dosing unit (for example the dosing unit of each reservoir) nor the receiving inlet of the container in which the bulk product components are to be combined are contaminated with foreign bulk product.

It is known to close each dosing outlet and/or receiving inlet by means of a slider to prevent contamination of the bulk product while the dosing unit is transported to the container as well as contamination of the surroundings with the bulk product. However, this necessitates frequent cleaning of such sliders if it must be ensured that residues of bulk products which cling to the sliders are not spread. Apart from this mechanism, further different closing mechanisms of the dosing outlets and/or receiving inlets are known, for example in the form of divisible shutters (EP 1 315 662 A1) or more or less conical plugs (EP 0 968 937 A1). One disadvantage of such closing mechanisms is the various substantial difficulties associated with their complex structure. This applies particularly to the closing shutters in accordance with the above-mentioned EP 1 315 662 A1. Another disadvantage consists in the fact that such closing mechanisms, such as the plugs in accordance with the above-mentioned EP 0 968 937 A1, are bound to result in sealing forces being transferred between the dosing unit and the container to be filled, so that gravimetric dosing, and in particular gravimetric measuring, of the bulk product poured into the container during the dosing process becomes very difficult or substantially impossible.

DE 603 10 369 T2 discloses a device for preferably contamination-free transport of bulk product from an upper container equipped with a dosing mechanism into a container disposed below it, wherein the upper container can be docked to the lower container. Gravimetric dosing, and in particular gravimetric measuring, of the bulk product poured into the lower container during the dosing process is also not possible in the device known from this publication. The same applies to a similar device according to EP 0 547 861 A1 and a device known from DE 295 03 812 U1 for preferably contamination-free transport of bulk product, whose dosing mechanism can be connected with the inlet of a receptacle by means of a collar.

DE 10 2005 014 930 A1 discloses a facility for gravimetric combining of individual bulk product components from several reservoirs, each with one respective dosing unit, into a transport container which travels between the reservoirs and receives the bulk product components from the respective reservoir according to the desired recipe. Each dosed amount of bulk product is gravimetrically measured by means of several weighing devices in the form of container scales disposed below the respective reservoir, onto which the transport container is placed by means of a lifting device. During the dosing process, the transport container, which rests on the weighing device, is lifted by means of the lifting devices of the weighing device to a level where its receiving inlet can be connected to the dosing outlet of the reservoir disposed above it, whereupon the bulk product component to be dosed is poured until the weighing device detects the desired weight. The container is subsequently lowered again, wherein its receiving inlet is decoupled from the dosing outlet, and the container is transported on to the next reservoir or towards an evacuation station.

Although this procedure has proven its worth in practice, the lifting devices of the weighing devices used, which have to shift the entire container between an upper docking position to the dosing unit of each reservoir and a lower transport position, cause considerable costs, which, for reasons of size, are higher the larger and heavier the container is configured.

The invention is based on the task of further developing a method and device of the above-mentioned kind while preferably avoiding the above-mentioned disadvantages in such a way that substantially contamination-free transport of the bulk product from the dosing unit to the container is possible while the amount of the bulk product dosed in each case is gravimetrically measured, wherein the transport can be carried out both using a simpler construction and in a more cost-effective manner than in prior art.

As regards the method, this task is solved in a method of the above-mentioned kind by ensuring that

• • the dosing outlet of the dosing unit is disposed at the dosing unit by means of an elastic joining element to avoid transfer of forces between the dosing outlet and the dosing unit,
    and/or
  • the receiving inlet of the container is disposed at the container by means of an elastic joining element to avoid transfer of forces between the receiving inlet and the container,
    wherein the dosing outlet/receiving inlet connected with each other are disposed in such a way relative to the dosing unit and/or the container that a transfer of forces between the dosing unit and the container is prevented by the elastic joining element.