The starting situation
Milled grain (made from both malted and unmalted barley) is mixed with water in a large mixing vessel (a lauter tun). The starches in the mash are converted into sugars and after a few hours the syrup called wort is strained and transferred to "wash backs" where the liquid ferments and the sugars are converted into low strength alcohol called wash. After fermentation the wash is transferred to the pot still where it is distilled three times. The spirit is then aged for at least three years in oak casks before it can be called whiskey.
The production process involves the transfer of large amounts of spent grain from the lauter tun to the feeds recovery plant where it is dried and prepared as high quality animal feed.
Traditionally expeller units and vast volumes of uncontrolled compressed air have been used to handle the spent grain, however this method consumes huge amounts of energy and can restrict plant productivity.
Due to the huge success and demand for its flagship brand, the distillery needed to increase the number of mashes from 30 to 45 per week. After plant modifications and upgrades were implemented the final bottleneck identified was the spent grain handling system and the time required to empty the lauter tun, which averaged 55 min.
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