The bag loader, developed by the Hamburg Company FTH – Fördertechnik Hamburg Harry Lässig, was very commonly usedin the 1970’s.
At the time containers were not closed as they are today and bags needed special equipment for transport.
Today, dependent on volume and destination, the use of standard containers instead of bags or even bulk is quite common and it takes advantage of the necessity of returning boxes to their original destination.
Feeding and post-cleaning and transportation, makes the use of containers in the end, quite expensive.
Therefore bag loaders or combined loader/unloaders or combined with bulk goods are still used for sugar, fertilizer, cement, and plastic.
Ship bag loader for sugar
This project was developed by Maquinas Condor Brazil and Neuero Industrietechnik in Germany with the support of former employees of FTHL.
The task was to make a complete bag spiral chute with loading head for a Cargill plant for sugar export in Guaruja, Brazil. The existing loader was loading 1,500 t/h bulk sugar and was replaced by a new 3,000 t/h bulk ship loader. This ship loader was partly dismantled and erected at the other side of the bag terminal. All this action of dismantling and new equipment assembly was done during ship changes without interruptions to operations.
The client also expressed the wish to have a bigger working range because of the fact that receiving ships are now bigger than in the past. The spiral chute with loading head is composed of:
• Receiving chute that introduces the bags to the spiral chute.
• Spiral chute. Its special shape controls the bag speed during loading. It has a section that allows telescoping through rotation movement.
• Lower rotating plate that at any position feeds the loading head.
• Loading head; this head rotates by approx. 270° and can reach 360° with the telescopic rotating movement of the spiral chute. It has telescopic belts that are adjusted in order to place the bag close to empty space. This telescopic movement allows for positioning the bags under the hatch wings.
Telescoping spiral chute
The spiral chute was developed in order to store bags and cartons continuously in the ship with a crew of only three people working. One person operates the controls while the others position themselves at the front of the loading head to guide the descending bags without wasting efforts to carry or turn them. The crew can change in alternating turns of 10 to 15 minutes. The machine capacity is up to 4,000 bags/hour.
To warrant a constant flow of bags, a bag store is required to compensate for interruptions and irregular arrival of bags. This storage area should be positioned immediately before the distribution area. The spiral chute is ideally suited to store a good number of bags without any additional costs, an advantage no other descending conveyor can offer.
Moreover, the spiral chute, contrary to other descending conveying elements, has no mechanical parts, hence no additional trouble factors.
Due to the special shape of the spiral, a constant speed is guaranteed regardless of bag size or material. In special cases, for example abrasive cement bags, the stainless chute plates may be covered with PU plates.
The telescoping spiral chute consists of the following parts:
• Torsion-proof welded platform in coarse sheet and section iron construction, with welded-in centre tube, linked to the boom by means of a radial ball-and-socket joint for maintenance-free operation due to plastic packings, and kept in a straight vertical position by a parallel guidance.
• Spiral chute in stainless sheet steel 2.5 mm thick, consisting of individual cascade shaped sections, with one side continuous welding, and outer reinforced flat iron border, properly grounded and stained after welding.
• Reinforcing basket in strong tube construction, enclosing the whole fixed part of the spiral chute.
• The fixed part of the spiral chute is provided with an antiweather-cover which can be demounted in small pieces.
• Winding stairs in the stationary part, with slide-proof steps, hand and leg rails (optional).
• Adjustable guide roller mounted on roller bearings protected by strong casing, and connecting link guide, both mounted on the main tube to pilot the telescopic part.