OPTIMIZATION OF THICKENING AND DEWATERING THROUGH AUTOMATION

The purpose of this project is to deliver a tool for organizations that are considering the automation of thickening and dewatering systems. This paper presents the findings of a literature review on dewatering instrumentation and the testing results from the first few facilities. The final report will provide a review of each automation package for function, ease of implementation, and cost effectiveness.Based on input, the project team has developed a research plan. Specific points that are being addressed in the research are:The instrumentation and control systems must be reliable on a long term basis and require a minimum amount of maintenance to be cost effective. This includes the ability to respond to and recover from process upsets.The test program and final report must consider that each facility evaluating the use of an automation system will have a different definition of optimum performance depending on operating conditions. Some facilities may target minimum polymer usage, while others are more interested in maximum cake solids or maximum throughput.The desired location of the control algorithm will vary from site to site. Generally smaller facilities will be interested in a “black box” to optimize the solids handling process. Larger facilities that have standardized on a certain PLC manufacturer are more likely to want the control algorithm fully integrated into their plant's existing control system. For the purposes of this testing, the automation package manufactures will supply their standard unit (black box) which will be integrated with the facility control system at a relatively high level.The combination of each facilities existing process automation and the optimization control package should allow for optimum performance of the solids handling process, with the goal of having an operator spend less than 25 percent of their time during the operation of the thickening/dewatering equipment.The results of this research are presented in this paper.