Data Analysis in a Batch Salami Ripening Chamber for Real-Time Process Monitoring and Control

The paper provides an analytical and visual view of what actually happened - on the process side - in a fully instrumented, pilot-scale, air ascending-flow chamber of industrial type for salami ripening. Since ripening is always characterized by a "slow" dynamics and limited variations in process variables, the time course of the curing air temperature and humidity, as well as the sausage heart temperature, did not show rapid or incomprehensible transients. The monitored variables clearly showed limited amplitude oscillations due to the "go" and "stop" air circulation pattern, that is the sequence of phases with either forced or natural circulation in the cell as imposed by the supervision system for the automatic control of the chamber set points. The effectiveness of set point tracking was favorably assessed for the experimental tests. Then, comparisons were made between different measurements of the same variable, e.g., air temperature and humidity, monitored by probes at different heights in the chamber; similarly, the temperature measured by a TC at the heart of the sausage was matched to the curing air temperature in the chamber. From these comparisons and other crossed checks among data, it was possible to obtain static (e.g. the effect of the position on air temperature at equal height) and dynamic (e.g., the sausage temperature response to the temperature variations in the chamber) assessments of the process variables. All in all, the work done and its further exploitation offer a tool set for a real-time aid to a factory operator.