A case study on improving energy efficiency of a Granulator in the polythene recycling machine

Sammanfattning: The thesis focuses on the improvement/enhancement of energy efficiency of the machine; called Granu-lator of the recycling process of polythene. In the recycling process, it is observed that energy is wasted unnecessarily, and thus energy efficiency must be improved. The reason is that the granulator has been operating with an old rotor. Therefore, the introduction of a new rotor to the main Granulator and im-provement of the energy consumption must be done simultaneously. The energy consumption to pro-duce a unit mass of useful output was calculated for the main Granulator with the old rotor. Thereafter, the new rotor is installed in the main Granulator, and the energy consumption to produce a unit mass of useful output is calculated. The energy consumption was calculated by observing and stating the current of the main motor of the main Granulator. The current was recorded and hence the energy consumption was calculated batch wise with the help of various factors such as part load efficiency, power factor, rated horsepower of the motor, etc. The total energy consumption was calculated by summing all the sub energy consumption units. Spe-cific energy consumption was calculated by dividing the total energy consumption from useful product. Similar inputs were used to feed the Granulator since it was very important for the comparison of both Specific Energy consumptions with old and new rotors. In addition, no motor was changed in both cases. Thus, it was very justified to conclude about the Specific Energy consumption. The same procedure was deployed for the old rotor and new rotor of the main Granulator. Thereafter two specific energy consumption levels were compared to decide which one is smaller. Finally, it numeri-cally found that the specific energy consumption decreased after installation of the new rotor to the main Granulator. The reduction of specific energy consumption in the granulator is 48.363 kJ/kg. This can be compared with the initial specific energy consumption of 256.485 kJ/kg, and final specific energy consumption of 208.122 kJ/kg.