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STORAGE
Digital services for the optimisation of the grain drying process
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by Volker Josel, Product Manager, Bühler GmbH, Germany
igh yield and ultimate homogeneity of the product are the main dryer requirements of a grain collection point operator. For this the energy input should be minimal, the drying process has to run without any disturbance and the product needs to be dried as close to the target moisture as possible. As a grain dryer is not an isolated element in the collection point, the interaction of the drying process with the other processes must be seamless. Over the years, various improvements in the design of grain dryers have increased their energy efficiency. One example is the reuse of heating energy, whereby an air recirculation system (not saturated, but hot exhaust air) is fed back into the supply air for the drying of grain, saving up to 20 percent of the energy required for heating. Another example is Bühler’s Eco Cool, which is used for the drying of very moist corn that has an input moisture of more than 30 percent. Eco Cool is a conditioning and cooling section after the actual corn dryer that enables a further 15-20 percent of the heating energy to be saved. While there are many examples of such mechanical dryer optimisations, tight margins and sustainability issues are also driving the need for further optimisation of the drying process to continuously reduce
80 | November 2020 - Milling and Grain
energy consumption, losses and waste. Optimisation of a grain dryer based on purely mechanical improvements, however, is now reaching its limits: • The design of today’s grain dryers is already mature, which means that further mechanical design improvements are laborious and very cost-intensive • Mechanical design improvements alone are also unable to exploit the full optimisation potential Optimisation needs to be balanced towards the achievement of many goals, with different parameters depending on each other. At the same time, a grain dryer has to work as smoothly as possible and be coordinated with the other machines in the collection point. This means that intelligent optimisation is required. Automatic Moisture controls are a vital first step towards intelligent optimisation. These control the drying process based on product moisture and, with the help of sensors and algorithms, the process is continuously adapted to ensure that the outlet moisture of the product is as constant and close to the target moisture as possible. With its new service “DryMate”, however, Bühler is taking a significant step further. This service comprises three components: • Automatic moisture control • Mobile view • Technologist report which are described below in more detail:
Automatic moisture control
This control is characterised by its accuracy