Pulp mill measures wood chip in real-time

Photo: Texo

Inc. of Baie D'Urfe, Quebec, Canada has introduced its Chip Management System (CMS) that provides online, real-time measurement of many important chip properties on the chip conveyor. TEXO's COOK-X advanced process controls (APC) use the measurements to manage chip filling, alkali to wood charging and stabilize digester cooking conditions.

CMS measures chip mass flow, moisture, volume, dry bulk density and bark content. The measurement system was developed by Centre de Recherche Industrielle du Quebec (CRIQ).

The patented chip measurements and APC controls have been successfully commissioned at a Canadian Kraft pulp mill.

According to Texo, the results are encouraging as impregnation vessel and continuous hydraulic digester levels have been stabilized, liquor to wood ratio is controlled to target and Kappa number variability has been reduced.

The measurements allow flash steam use to be optimized in the pre-steaming operation, while reducing venting to the atmosphere, allowing displaced fresh steam to be used in the mill's turbine. This provides an extra 2 MW of electricity to be sold on the grid. The ultimate purpose is to control the digester blow line Kappa number and achieve stability in power production.