New Challenges for Quebec and Ontario Paper Company Ltd., 1991 International Mechanical Pulping Conference Proceedings

This paper describes the main features of the modernization project launched in 1988 by Quebec and Ontario Paper Company Limited (Q&O) at its Baie Comeau, Quebec mill. The PRMP plant, which has a capacity of 600 BDMT/d, consists of two chip washing systems, three refining lines, two-stage pressurized main line screening, cleaning and thickening, two pressurized rejects refiners, a dedicated rejects screening and cleaning system and a heat recovery unit handling the steam from the eight refiners. The project also included a new electrical substation, woodroom modernization with a new chip receiving, screening and distribution system, OPCO plant improvement by the addition of a new reactor and the modification of an existing refiner to allow operation as a pressurized primary or an atmospheric secondary, GWD pulping capacity reduction and modification to the rejects screening, HYS plant shutdown, modification to the acid plant and two new storage tanks.

The PRMP project was carried out in an innovative manner. It stressed strong involvement of the Q&O project team,

complete responsibility for process design and equipment layout by the major equipment supplier, and responsibility for detailed engineering, procurement activities and construction contract preparation by Sandwell Inc., a consulting engineering firm.

A description of the technical aspects of the project is given with special emphasis on the PRMP plant, highlighting technical innovations such as pulp mixing boxes at the discharge of the secondary and rejects refiners to permit continuous automatic freeness measurement for the refiner specific energy control loop, and the interlock diagnostic capacity developed in the distributed control system for ease of startup.