Method and device for monitoring the energy management of dryer systems for plastic granulate, and method and device for drying plastic granulate

A device for monitoring energy management in a dryer system for plastic granules, wherein a dryer system comprises at least one device for drying plastic granules, which has at least one drying chamber, a feed device for plastic granules, a blower and a heater, wherein the device for monitoring the energy management of a dryer system for plastic granules comprises:

• at least one first temperature sensor arranged in a region of a process air inlet of the drying chamber to measure an inlet temperature of the process air;
• at least one second temperature sensor arranged in a region of a process air outlet of the drying chamber to measure an outlet temperature of the process air;
• at least one third temperature sensor for measuring an inlet temperature of the plastic granules;
• at least one process air mass determination device;
• and at least one evaluation unit, the evaluation unit being configured to determine a difference between the inlet temperature and the outlet temperature of the process air so that, taking into account heat capacity of air, a specific energy input is determinable and so that, taking into account a mass of supplied process air, an absolute energy input by the process air is determinable, wherein a throughput of the plastic granulate is determined by the evaluation unit and a target temperature for the plastic granulate is retrieved and a difference between the target temperature and the input temperature of the plastic granulate is determined and a specific energy requirement is determined from the temperature difference, taking into account the specific heat capacity of the plastic granulate.

A method for monitoring energy management of a dryer system for plastic granulate, comprising the steps of:

• specifying a target temperature for the plastic granulate;
• measuring input temperature of the plastic granulate;
• determining a difference between a target temperature and the input temperature of the plastic granulate;
• calculating an energy requirement for drying the plastic granulate and increasing the input temperature to the target temperature;
• measuring an inlet temperature and an outlet temperature of process air at a drying chamber;
• determining a difference between the inlet temperature and the outlet temperature of the process air;
• determining mass of the process air fed into the drying chamber;
• calculating energy introduced into the plastic granulate by the process air;
• and
• outputting values for the energy requirement and the introduced energy.