FLOW CONDITIONS IN ROTARY IMPELLER PACKER S

The rotary impeller filling system has been used for bagging cement si nce the start of the 20th century. Alternative designs were developed in the mid 80s, and were also put to the test under practical conditio ns. The flow conditions in the turbine impellers were investigated in scientific trials and the measurements were evaluated with the aid of well-known fundamental equations. The optimization which this made pos sible was utilized to make a significant improvement in the bagging ca pacity with products with finenesses of over 10000 Blaine and to achie ve a considerable decrease in wear. In the meantime, practical tests w ere carried out which fully confirmed the numerical calculations and t he experimentally determined data. A new electronic weighing system wa s also developed which, in a cycle of 23 ms, measures the mass flow co ntinuously and calculates and optimizes all parameters for the changeo ver between coarse and fine flow as well as the run-on correction. Any change in the flow behaviour of the product is determined within this cycle time. All the parameters are then adjusted independently to the situation so that exceptional weight accuracy is guaranteed when the bagging machine is operating at full capacity. Automation modules such as empty bag applicators and automatic palletizers are available to m ake continuous use of the full capabilities of the new packer; these a utomatically undertake any changes in product, bag weight or stacking pattern.