Fresco Systems Australasia have completed the first stage of a new facility in Japan with the supply of 40 bulk bag unloaders complete with metering screw feeder dischargers and individual control systems. Fresco Systems Australasia were involved in the early stages of the project assisting in the design of the materials handling systems.
The plant had a tight specification on dust emission and system dosing accuracy. Some other criteria included the ability to load and unload the bulk bags in a central location to keep the process area clean to pharmaceutical standards. This meant the whole bulk bag unloading station was removed from the process area by overhead gantry crane and taken to an area where the bulk bags could be changed.
The system comprised 4 rows of 10 bulk bag unloader stations with each row having an overhead gantry crane. Fresco Systems Australasia developed a quick connect system for the gantry crane that allowed the attachment and detachment of the bulk bag unloader station by the operator without having to manually intervene. This concept provided a cost-effective solution to the application, saving the customer from purchasing 40 individual electric hoist and trolleys.
As all 40 units were for different materials, a versatile design that would accommodate a range of bulk densities, particle sizes, flowability and numerous bulk bag dimensions were needed. This was achieved using Fresco Systems Australasia’s range of bulk bag unloaders including the height adjustment for the bulk bags.
Each bulk bag unloader has four fully adjustable sturdy uprights, which allows for any size of bulk bag by simply removing the retainer pins and adjusting the vertical height of the support frame pockets. The various sized bulk bag discharge spouts easily clamped into Fresco Systems Australasia’s spout clamp providing a dust tight seal preventing dust escaping to the surrounding area.
During the bag removal stage, the dust collector evacuated air from the bulk bag and collapsed it to allow the operator to remove and dispose of it safely, without the need to crunch and roll up the empty bag, releasing dust laden air into the environment. A liner tensioner wound up the liners from some of the bulk bags preventing them from slipping into the hopper above the metering screw feeder. This restricted the flow of the product from the bulk bag causing inaccuracies with the flow of material into the mixers below.
Each metering screw feeder was fitted with an agitator to condition the product prior to entering the screw ensuring consistent flow of the product irrespective of the head load. A flow restrictor fitted to the metering screw feeder discharge spout prevented the material spilling or flushing while the bulk bag unloading station was in transit to the bag change position.
The electrical system incorporated motor starters, overloads and a variable speed drive so the metering screw feeder screw could be slowed to a dribble feed in the final stages of loading the mixer. With the mixer on load cells weight feedback controlled the system providing high accuracy.
The unusual voltage in Japan was a challenge but it was overcome with the use of a Bonfiglioli process power converter. Each system was required to be supplied with a plug so it could travel with the bulk bag unloader station during the bag change.