reduced periphery pATTERNS

Opportunities exist to optimize the energy requirements for all refining systems by minimizing gross power consumption and refining at the proper intensity. Reducing the active plate diameter is the best low cost approach as long as both the bar edge length and hydraulic capacity of the plate are maintained. In all pump-through refiners, power is consumed in two different ways:

  1. Power is applied directly to fibers as they are impacted between opposing rotor and stator bars. This is referred to as the net power or energy. Refining intensity determines the amount of net energy required to achieve a given quality change in the fiber.
  2. A portion of the power is also consumed as a result of hydraulic pumping effects and energy loss associated with viscous shearing of the fluid. This is called the 'no load' power and is measured as the power consumed with plates backed out and stock flowing through the refiner.

For all fiber types, significant energy savings can be achieved by reducing the refiner no load which can be considered as 'wasted' power since very little is effectively absorbed by the fibers. No load power is primarily dependent on refiner plate diameter and rotational speed according to the following relationship:



where k is a constant determined by the refiner plate bar/groove geometry.

Given that motor speed is typically fixed, reducing the active diameter of the refiner plate presents a very significant opportunity to reduce no load horsepower. However, in order to maintain quality and process requirements, reduced diameter plates must maintain total bar edge length and have sufficient groove volume for flow capacity.

With FINEBAR® reduced periphery plates, no load power requirements can be minimized while still maintaining groove volume as well as high bar edge length for low intensity refining. This results in significant power savings without impacting quality or process flow requirements. The table below shows examples of potential energy savings that would result from a reduction in the active diameter of refiner plates operating at typical speeds.