Micro-Ingredients Carry-Over during Bucket Elevator Handling in Feed Industry: Influence of Process Parameters

Currently, carry-over level of feed production lines can be accurately defined, but the causes are not identified yet because of a misunderstanding of this phenomenon. On-site studies charged conveying equipment between mixer and pelleting press, and especially bucket elevator, to be responsible for carry-over level increasing. A series of experiments has been carried out on a bucket elevator test bench in order to determine how process parameters influence carry-over phenomenon. Product deposits on equipment walls represent, on average, 3.0% of the initial batch mass and contain about 0.2% of micro-ingredient after one tracer batch passing and 0.1% after flushing batch passing. Experimental design results showed that parameters acting on micro-ingredient deposited are different from those influencing collected product. Therefore, optimal position of tested process parameters will depend on the batch objective regarding its position in the production schedule. Practical Applications This work allows a new approach of understanding carry-over phenomenon at pilot scale. Indeed, process parameters acting on micro-ingredient deposits by a batch “n” have been differentiated from those acting on micro-ingredient gathering by a batch “n + 1”. By this way, the results of this experimental study brought industrial solutions to control micro-ingredient transfer, considering the batch position in the whole sequencing.