The Big Bag (FIBC) is a widespread transportation bundle for the most different kinds of bulk solids that has been used for many years. Filling, emptying and the dust-free disposal of the Big Bags is one of the essential core competences of EMDE Industrie-Technik GmbH. In autumn 2013 a fully automatic Big Bag emptying system for granular pitch was commissioned in Bonn for a graphite manufacturer. The emptying device from EMDE is at the beginning of a manufacturing process for isotonically pressed graphite, which, amongst other things, is used for the production of LEDs and solar modules.
As regards the concept of the plant, great importance was attached to operational safety, ease of operation and low dust content. A protective safety casing of the plant, the automatic emptying process, the operation outside the danger zone at a separate operating cabinet including operating panel are the important integral parts of the operational safety concept of the overall system (Fig. 1).
At the beginning of emptying the Big Bag passes a quick-acting gate to reach the suspension position, and the four supporting loops are suspended in the special cross bar (Fig. 2). After closing the gate from outside, the automatic mode is started and the Big Bag is lifted to the emptying position by means of an electric chain hoist. The bottom of the Big Bag is cut open almost fibre-free, after having been put down on a cross knife including piercing point. An intermediate container receives the complete contents of the Big Bag. Then the product is passed into storage containers via a subsequent encapsulated conveying system where it is stored for further processing. In the next step the empty Big Bag is passed to the Big Bag compactor to reach the discharge position and is automatically loosened from the cross bar. This is achieved by opening (swivelling open) the load hook by means of an electrically actuated linear cylinder. The empty Big Bag falls down into the screw compactor, is taken by the degressive and conical compactor screw and is compacted in a following pressing bag (Big Bag) suspended via 4 toggle tighteners (Fig. 3).
The evaluation of the emptying cycles shows the operator at the panel when it is necessary to change the pressing bag. Then the electric chain hoist including the cross bar returns to the suspension position and the process starts again. Due to the optimized process steps, the overall process time amounts to 3.5 minutes only. The electric chain hoist is positioned at the corresponding functional positions by means of a path coding system. A very efficient filter plant carries out the dedusting of the plant. The dust is safely and efficiently sucked off at the crucial emission sources. Thus, an almost dust-free handling is ensured.
This type of plant is certainly no standard product “off-the-peg”. Their concept is developed in close cooperation with the customer (Fig. 4). The plant design, the manufacture of all plant components as well as the control system are carried out by EMDE. Of course, this also includes the installation at site, the following commissioning and the training of operators.