A paper mill was struggling with excessive energy consumption and premature friction wear on felts due to high Uhle box vacuum levels (averaging 11.61 inHg). Friction between suction boxes and fabrics account for an estimated 5% of press section energy use. Additionally, excessive vacuum levels reduce felt life. The plant sought a way to reduce Uhle box vacuum levels without compromising moisture removal.

PRG partnered with the facility to assess roll condition and identify improvement opportunities. Analysis revealed that the press rolls had worn profiles and poor roundness, limiting the effectiveness of water removal through grooves, inadvertently pushing more moisture into the felt. 

PRG ground the press rolls with a focus on improved profile accuracy, enhanced roundness, and axle concentricity to roll face.
 
Following the installation of the PRG-ground rolls improved water removal through roll grooves reduced felt saturation and vacuum demand. With more effective dewatering at the press nip, the system relied less on suction. Average Uhle box vacuum dropped 17% from 11.61 to 9.56 inHg resulting in 25 horsepower of energy savings, an annual energy savings of more than $10,000.

In the press section, precision-ground rolls are essential for effective moisture removal and energy efficiency. PRG restores rolls to exacting tolerances by correcting profile, roundness, taper, and concentricity, which enables efficient moisture removal through the roll grooves and reduces over-reliance on the felt and vacuum systems. Lower vacuum needs mean lower power consumption, less wear on felts, and extended equipment life. Contact your PRG representative to see how press roll optimization can reduce dryer load and improve bottom-line results.