New process-water filtration system cuts power usage

MüNSTER –A system that removes dirt and fine particles from process water in underwater pelletising substantially cuts power consumption in water filtration and reduces overall pelletiser energy consumption by nearly 10 to 17%. The system from Nordson BKG is being introduced at this year’s Fakuma 2014 (Hall A6, Stand 6404).

The Optigon water filtration system eliminates need for a separate fines-removal sieve, which in standard systems requires a secondary, dedicated water pump. Instead, all filtration is provided by a Polygon drum filter, whose 70-micron screens are finer than the 150-micron screens used in standard systems. Driven by a small motor, the drum rotates within the water that is circulated throughout the pelletizing system by the main process water pump. The filtration system is designed so that dirt and fines stay confined inside the drum until they are evacuated into a collecting basin outside the tank.

By eliminating the secondary pump, the Optigon water filtration system uses only 1,440 KW per year (measured at 8,000 hours), as against 44,000 kW and 98,480 kW for the company’s Opti-Line and Poly-Line? systems, respectively. Since water filtration typically accounts for 10 to 17% of the energy consumption in underwater pelletizing, the energy efficiency of the Optigon system means that overall consumption is cut by nearly that much.

 According to Adam Cowart, global product manager for Nordson BKG: “The Optigon system drastically reduces power consumption for process water filtration by, in effect, letting gravity do the work once done by a separate pump.” The innovation is part of Nordson BKG’s programe of continuous improvement to reduce environmental impact and increase energy efficiency.

 Other energy-saving measures developed by Nordson BKG are two that are available to customers as optional features: 1) complete insulation of the water system to prevent loss of heat to the workplace and serve as touch-protection for workers; and 2) insulation of the die plate heating flanges, ensuring a uniform temperature profile in the flow channels and retention of heat in the die plate, with energy savings of 30% compared with standard die plates.