| |
TAPPI Papers
The following paper was presented at TAPPI 1995 Internation Environmental
Conference.
Effluent Reduction
Through Process Optimization - A Case Study
|
Daniel Parker, P.E.
President
Parker, Messana & Associates
Federal Way, Washington 98003Robert M. Seamons
Process Engineer
CH2M HILL
Bellevue, WA 98009 |
Mike Anderson
Engineering Manager
Boise Cascade Corporation
Vancouver, WA 98666Frederick Weber
Environmental Engineer
Boise Cascade Corporation
Vancouver, WA 98666 |
ABSTRACT
The Boise Cascade, Vancouver Paper Mill is
facing increasingly strict effluent discharge requirements, both from local regulation and
proposed EPA limits. The mill is also planning to increase secondary fiber production
which will increase effluent pollutant loading. The cost of upgrading the existing
effluent treatment system to meet the proposed limits was found to be prohibitive. Lower
cost alternatives for meeting the discharge requirements were investigated, combining
modifications to the existing treatment system with reduction of effluent within the
process.
A complete survey and characterization of
the plant process effluent were conducted, and a series of projects developed to reduce
effluent flow and solids. A solids and water balance was developed for the plant and used
to verify the expected results of the proposed effluent reduction projects under various
production scenarios. This showed that the plant effluent flow could be reduced by nearly
50% through a series of projects to recover and recycle filtrate and seal waters. The
process effluent reductions, in conjunction with upgrades to the existing effluent
treatment system, enabled the proposed limits to be met at a considerably lower cost. The
process effluent reduction projects had the additional benefit of showing a return in
reduced operating costs, and increased fiber recovery.
 |
IEEE Papers
The following paper was presented at the IEEE 31st Annual Meeting in San Diego, Oct
6-10, 1996.
High Performance,
Low-Budget Distributed Control System
|
Kevin H. Stively
Process and Control Engineer
Industra Inc.
16300 Christensen Road, Suite 300
Seattle, WA 98188, USA
(Presently with Parker, Messana & Associates) |
Lawrence A. Keiver
Electrical and Instrument Superintendent
Western Pulp Limited Partnership
Box 2000
Port Alice, BC V0N 2N0, Canada |
ABSTRACT
The mill was faced with the problem of
installing a new, modern wastewater treatment plant using sophisticated controls in an
existing pulp mill with old, stand-alone controls and instrumentation. An added
requirement was that the new system be suitable for future improvements in the production
facility. In addition, the system had to be suitable for operation and maintenance in a
remote location by a small staff. Complete replacement of controls with a modern
distributed control system (DCS), though attractive technically, was out of the question
financially.
The system selected utilizes conventional programmable
logic controllers (PLCs) with Ethernet and DH+ communications links, integrated with
existing controls and designed for upgrades of the entire production facility. More than
4400 rungs of PLC code were written. To control the processes, 87 control screens and 13
trend pages were created. This paper describes the rationale used to approach the problem,
compares alternative solutions, touches on significant details of installation and
commissioning, and reports on system performance.
|
|
