On-line control and optimisation of the pelleting process of animal feed

A method is presented for the generation of advice for the on-line control of the pelleting process of animal feed. The method is based on the idea that some of the process variables can be considered constant during the pelleting of one batch. We use data of batches being produced under more or less the same processing conditions to construct equations for the output of the process. These equations are used to define a linear programming problem. The objective of this program is to maximise the productivity while maintaining acceptable pellet quality. Its solution represents advice for the on-line control of the batch. A series of 20 test runs shows that implementation of the method results in a considerable increase in productivity and decrease in the use of energy. We use information on the first part of the run to improve the equations of the output. The test runs show this second iterated advice results in an even higher increase in productivity, while the decrease in the use of energy stabilises.