GreyStone’s Log Washer Produces Efficiency, Consistency

Fri February 09, 2007 - National Edition
Construction Equipment Guide

GreyStone Inc.’s new automated log washer assists log washer operators keep output quality consistent without having to make frequent manual adjustments to the angle of inclination.

The automated log washer with a hydraulic support system comes with a PLC sensor that detects the tonnage going through the unit. When the tonnage decreases, the system detects this and increases the angle of inclination until the sensor detects the proper tonnage. If tonnage increases, the hydraulic system automatically decreases the angle of inclination until the proper tonnage is detected.

Upper and lower limit switches are employed to prevent excess inclination or damage to the unit.

Log washers remove tough plastic clays from coarse aggregate by scrubbing the material with paddles, causing an abrading action. These units can break down clay and liquefy it by causing rock to grind against rock. It is important to have enough particles in the log washer at any given time to create the desired rock-on-rock action. Log washers typically operate at inclinations between 5 and 10.5 degrees.

As the angle of inclination increases, output capacity of the unit decreases, with a corresponding increase in retention time. Decreasing the angle has the opposite effect: increased capacity and a decrease in retention time. This makes the angle of inclination vital.

In most applications, the feed rate is set and the angle of inclination can be adjusted through a costly trial-and-error method until the desired output (clean rock) is achieved.

Automating the variable incline section of the log washer with GreyStone’s new unit removes the need for human input beyond an initial calibration by the operator.

For more information, call 888/346-9274 or visit