NXE:3400 OPC process monitoring: model validity vs process variability

Author(s):  
Dongbo Xu ◽  
David Rio ◽  
Werner Gillijns ◽  
Max Delorme ◽  
Christina Baerts
2016 ◽  
Vol 2016 ◽  
pp. 1-13
Author(s):  
Dong Xiao ◽  
Jinhong Jiang ◽  
Yachun Mao ◽  
Xiaobo Liu

With the development of modernization, the application of seamless tube becomes widespread. As the first process of seamless tube, piercing is vital for the quality of the tube. The solid round billet will be transformed into a hollow shell after the piercing process. The defects of hollow shell cannot be cleared in the following process, so a monitoring model for the quality of the hollow shell is important. But the piercing process is very complicated, and a mechanism model is difficult to build between the qualities of the hollow shell and measurement variables. Furthermore, an intelligent model is needed. We established two piercing process monitoring and fault diagnosis models based on the multiway principal component analysis (MPCA) model and the multistage MPCA model, respectively, and furthermore we made a comparison between these two concepts. We took three ways to divide the period based on process,K-means, and GA, respectively. Simulation experiments have shown that the multistate MPCA method has advantage over the MPCA method and the model based on the genetic algorithm (GA) can monitor the process effectively and detect the faults.


2005 ◽  
Vol 38 (12) ◽  
pp. 1025-1034 ◽  
Author(s):  
Dong Soon Kim ◽  
Chang Kyoo Yoo ◽  
Young Il Kim ◽  
Jae Hak Jung ◽  
In-Beum Lee

Author(s):  
Anand Tharanathan ◽  
Jason Laberge ◽  
Peter Bullemer ◽  
Dal Vernon Reising ◽  
Rich McLain

1998 ◽  
Vol 49 (9) ◽  
pp. 976-985
Author(s):  
M Wood ◽  
N Capon ◽  
and M Kaye

TAPPI Journal ◽  
2018 ◽  
Vol 17 (05) ◽  
pp. 295-305
Author(s):  
Wesley Gilbert ◽  
Ivan Trush ◽  
Bruce Allison ◽  
Randy Reimer ◽  
Howard Mason

Normal practice in continuous digester operation is to set the production rate through the chip meter speed. This speed is seldom, if ever, adjusted except to change production, and most of the other digester inputs are ratioed to it. The inherent assumption is that constant chip meter speed equates to constant dry mass flow of chips. This is seldom, if ever, true. As a result, the actual production rate, effective alkali (EA)-to-wood and liquor-to-wood ratios may vary substantially from assumed values. This increases process variability and decreases profits. In this report, a new continuous digester production rate control strategy is developed that addresses this shortcoming. A new noncontacting near infrared–based chip moisture sensor is combined with the existing weightometer signal to estimate the actual dry chip mass feedrate entering the digester. The estimated feedrate is then used to implement a novel feedback control strategy that adjusts the chip meter speed to maintain the dry chip feedrate at the target value. The report details the results of applying the new measurements and control strategy to a dual vessel continuous digester.


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