Melhoria do nível de controle da separação primária entre amido e glúten em uma refinaria de milho

Abstract

Ingredion Incorporated is a Business to Business (B2B) company that operates in the field of processing and refining industrial ingredients of agricultural origin, mainly corn-based. The first process in the corn refining chain is Wetmilling and the objective of this step is to separate the grain components (husk, germ, starch and gluten) with maximum purity, minimum energy use and minimum losses. In this way, the production yield of each component is determined. In order to improve operational performance, the reliability of the Grinding stage and increase the gluten yield of the factory located in the municipality of Mogi-Guaçu, São Paulo, the insertion and replacement of instruments with better performance and technology was planned. The operation would then be carried out automatically using a Proportional Integral Derivative Controller (PID). In Wetmilling, the separation of starch and gluten is carried out through separating centrifuges and, therefore, to ensure a good quality of the process, it is necessary to control the underflow and overflow currents. Normally, underflow density is controlled through instrumentation. Inadequate separation leads to low final gluten yield, in addition to starch loss. As a recommendation for the installation of density meters, it is essential to monitor the following factors: fluid aeration (existence of air bubbles) and accumulation of material in the lines and in the instrument. In this work, the application of a density measurement system will be presented, to carry out a more rigorous control of the underflow of the separation centrifuges. This system was composed of a deaeration box, a mass density meter - which operates on the principle of the Coriolis Effect - and a v-ball control valve. In addition, a Clean in Place (CIP) system was foreseen, since the cleaning of the instrument proved to be very relevant to its performance. Using the recommendations of Ingredion's Corporate Engineering, a standard operating procedure was created to collect several samples from the underflow and measure its density in °Be through a standardized analytical procedure. Subsequently, the data obtained was treated, seeking to compare the measurement on the bench and that indicated by instruments with different operating principles (Coriolis and pressure difference). After verifying the credibility within the process, the best hydrometer option was selected considering the aspects previously discussed and other points involving issues of safety, operation, interlocks and stop/outage that affect the density measurement system developed by Ingredion discussed.