We have recently completed a starch feeding & weighing system for a soup manufacturer. The system was designed to discharge from big bags into bins, with high accuracy weighing & no dust emissions.

Starch is used in the making of soups and sauces and various grades and quantities are added. Starch was being emptied manually from 25kg sacks into mobile bins that were taken to different mixers located around the factory. Due to the high starch usage, the ripping and tipping of sacks involved much manual handling and unacceptable levels of dust emissions.

Improvements were required to the operation and the following criteria had to be met: a reduction in manual handling; reduced dust emissions; high accuracy weighing; ingredients dispensed quickly; system able to use various grades of starch.

Starch can be difficult to handle in bulk, it can easily bridge when compacted but when loose or aerated it can behave like fluid. Aptech proposed a unique Big Bag discharge and weighing system to precisely control these characteristics and meet all of the customer’s requirements.

The system was designed in food quality stainless steel using box section with ledges avoided where possible. Bags are loaded on the station via an electric hoist.

The base of the bag sits on a hopper and seals onto a neoprene membrane, the bag spout is untied via an access door which is interlocked with a dust extraction system.

A bin is slid off a trolley onto a roller track mounted on a platform scale. The operator inputs the target weight into the weigh controller and the system is initiated.

A ‘Hogan’ louvered valve opens fully and vibrates to enable very quick product discharge into the bin. Dust extraction points located at the bin and chutework ensure no dust is emitted. When 90% of target weight is reached the Hogan louvered valve partially closes giving a trickle feed which enables weighing accuracy to within a few grammes. When target weight is reached and after an auto in-flight calibration has been made the valve fully closes and the bin is ready to be taken away.

Various grades of starch are used and sometimes it is necessary to change partially emptied big bags. The system incorporates and Iris valve located at the top of the bag outlet spout. When the valve is closed the bag spout is pinched and closed enabling the operator to tie off the bag spout. The valve is then opened and the partially emptied bag can be removed and changed for a different starch grade.