Novel Methods to Reduce Cost and Improve Sheet Properties Using Advanced Microwave Water Measurement Technology

摘要

Since the introduction of planar microwave technology in the year 2000, the number of instrument types and applications has grown substantially. A short introduction outlines the method of operation of planar microwave instruments and discusses the differences between this technology and other types of moisture measurement instruments. Additionally, the various types and applications for each type of instrument are described. Then a series of never-before published case studies are shown in detail with results quantified as follow: 1. Case Study 1 is of a Coated Board machine which was having issues with poor ply-bond. After installation of the proper types of instruments, the machine experienced a 15% improvement in ply-bond strength, while simultaneously reducing drive load in the forming section by 15%. Overall, this resulted in a 7-month ROI. 2. Case Study 2 describes a Kraft Liner machine with poor formation issues. After installation of the proper microwave instruments and accompanying trials, a 14% improvement in formation was measured, while noting a 315 kW/hr. reduction in drive load. This last improvement generated a 3-month ROI. 3. Case Study 3 involved a Test Liner Machine with ply-bond issues. As a result of having the correct instruments and a thorough trial plan, the machine produced a sheet with a 10% improvement in ply-bond (which resulted in a substantial reduction in starch usage) and an 11% reduction in drive load. These changes gave the mill a 7-month pay back. 4. Case Study 4 is another Test Liner machine looking to reduce sheet breaks and stabilize their process. In this case instruments were installed in both the forming and press sections. Based upon these measurements, the process of water removal was modified to have more water moving upward through the sheet. The final improvements also involved minor changes in both the wire and press fabric designs. In addition to the desired reduction in sheet breaks, a 20% reduction in drive load was captured, resulting in a 6-month ROI. A series of Conclusions drawn from these trials is presented to end the paper.