Journal of Korea Technical Association of The Pulp and Paper Industry (펄프종이기술)
- Volume 31 Issue 3
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- Pages.35-46
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- 1999
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- 0253-3200(pISSN)
Process -dynamic Model for Stock-fluid in a Pressurized Paper Machine Headbox
초지기 가압-헤드박스 내 지료유체의 공정-동특성모델
Abstract
Mathematical modeling provided a systematic analysis for the dynamic behavior of stock fluid in a paper machine pressurized headbox. Dynamic responses of liquid level, sheet basis weight and hydraulic pressure were predicted from the simulation model which represents the system. A unit step and asinusoidal wave load were considered as the input forcing functions in the headbox. Results are summarized as follows : 1. The dependence of sheet basis weight on liquid level in the pressurized-headbox was non -linear. 2. Liquid level in the head-box showed first-order lag with a unit step forcing to fluid input rate ; 3 . The amplitude of wave response of liquid level was inversely proportional to the time content for the sinusoidal input changes ; 4.Sheet basis weight showed second-order oscillating underamped responses for the step input load of flow rate ; 5. The damping factor in the second-order system was a function of air-pressure in the headbox ; and, 6. Dead-time existed in the measuring process for the headbox slice pressure.
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