05.07.2016
Enhanced efficiency when emptying big bags of products with fat content.
A wonderful solution that makes the process go faster.
When emptying big bags, the highest requirements for safety and product handling must be fulfilled. Especially emptying bulk solids that contain dust and/or fat and adding them to the production process require system solutions that are reliable in operation and tailored to the product. Moreover, instead of only being adapted to the structural conditions on the part of the customer, they also have to ensure a high throughput capacity. One such current project from bulk solids experts J. Engelsmann AG in the cosmetics industry demonstrates this.
A certain globally active corporation in the consumer goods industry manufactures, among other things, cosmetics and personal care products for everyday use. For its factory in Russia which manufactures bars of soap, the consumer goods manufacturer was looking for a system for emptying big bags for integration into the production process. In contrast to the emptying station used until now, this system solution should effect a considerable increase in productivity and, in relation to this, a higher throughput capacity.
The big bags with soap noodles should be emptied as completely as possible and conveyed into an on-site mixing container. Until now, an old big bag system which does not allow for any increase in capacity has been used. Furthermore, a screw without a discharger was used. This meant that the soap noodles, which stuck and clumped together because of their high fat content often plugged up the screw, which prevented the desired feeding accuracy from being attained. Moreover, soap noodles readily form a “soap dust” and also tend to form bridges. These are the properties of the product that had to be taken into consideration when constructing and manufacturing the new emptying system.
Pilot-system testing provides system solution suited to product and requirements
Because a big bag emptying system for a product with similar properties has been in use for some years in another of the cosmetic manufacturer’s factories with good results, the supplier of that system, J. Engelsmann AG, was contacted in order to enquire about an appropriate system solution. Just as with the first big bag system, the first item on the agenda was conducting trials in Engelsmann’s own technical center. Because of the complex requirements of the product and process, an experimental construction that simulated the emptying of big bags which was based on the principles of the previous system solution using the original product was set up in coordination with the customer. This pilot system testing brought not only important realizations about what adjustments have to be made to fit the product, but rather also the assurance for all involved that the system will fulfill the challenges posed during live operation later.
To empty big bags in the most efficient way possible, the system developed by Engelsmann was designed to throughput eight big bags (of 1.5 metric tons each) per hour. It is equipped with an emptying station, a crane runway module with an electric chain hoist with a flat construction to convey the filled big bags to the station. For this, the loading gear, which is fastened to the chain hoist and equipped with spring lift, is backed out and released at the position of the big bag located on a pallet. Then, the four loops on the big bag are hung over the retaining hooks of the loading gear and brought into the emptying position with the chain hoist integrated in the frame. In the next step, the big bag opening is connected to the emptying unit with a manually operated sealing plate without creating any dust. Then it is opened and the emptying process is started. In order to facilitate the option of partial emptying as was requested by the customer, a device for re-closing the partially emptied big bag is integrated in the frame and connected to the system controls. This means the big bag can be unfastened again and taken from the station.
Discharge with the dosing screw ensures smooth product flow
The dust created when the soap noodles are emptied into the system is vacuumed away using a dust extraction filter in the filtering system right next to the emptying system. Because the soap noodles demonstrate poor flow characteristics because of their inherent properties, a discharge device was installed to help the noodles along. A tumbler is implemented for this, which also serves to prevent the noodles from falling if the loops on the big bag should tear. Furthermore, the surfaces of the interior and any parts that come into contact with the product were sanded and polished in order to prevent the noodles from sticking. How much is discharged is controlled using a double screw and a fully automated weighing system. The signals of the on-site container scale are evaluated by the control mechanism and transmitted to the screw for coarse and fine dosing. A flexible compensator is used to detach the screw from the scale. The screw draws the product in and breaks it up using specially placed paddles so that any clumps of the product are dissipated. The threaded form of the screw’s discharge component is adapted to the product and flow properties of the soap noodles which means that these are best conveyed through the screw in a broken up state. After this, the product goes through the down pipe, the shut-off valve and the exhaust lock to reach the mixing container available on-site.
In order to guarantee safe handling on the part of the operating personnel, the emptying system is equipped with a safety guard in accordance with German accident prevention regulations (German, UVV). Furthermore, there are safety switches in the direct vicinity of the station. For installation located in a production area where there is a risk of explosion, the entire system was designed to coincide with the European Union ATEX directive. This system for emptying big bags has a CE mark and was delivered four months after the order was placed. It is a turnkey solution which was designed, produced, delivered, assembled and put into operation by Engelsmann. In contrast to the previous emptying system from another provider, the throughput capacity was increased by over 50% per hour thanks to the more precise measuring and the shorter machine downtime because the paddle screw no longer becomes clogged up.