The use of laser induced processing fume as a process measurand in the feedback control of laser cutting

2003 ◽  
Author(s):  
Leon Lobo ◽  
Karen Williams ◽  
John R. Tyrer
Keyword(s):  
Feedback Control ◽  
Laser Cutting

Method to evaluate residual stresses in the laser cutting process

2002 ◽  
Vol 12 (1) ◽  
pp. 27-41 ◽  
Author(s):  
Y. Zamachtchikov ◽  
F. Breaban ◽  
P. Vantomme ◽  
A. Deffontaine
Keyword(s):  
Residual Stresses ◽  
Laser Cutting ◽  
Cutting Process

Use of vent stack temperature as a feedforward variable for dissolver total titratable alkali (TTA) control

TAPPI Journal ◽  
2018 ◽  
Vol 17 (05) ◽  
pp. 261-269
Author(s):  
Wei Ren ◽  
Brennan Dubord ◽  
Jason Johnson ◽  
Bruce Allison
Keyword(s):  
Feedback Control ◽  
Current Practice ◽  
Feedforward Control ◽  
Control Variable ◽  
Indirect Measurement ◽  
Tight Control ◽  
Transfer Lines ◽  
Green Liquor ◽  
Process Dynamics ◽  
Downstream Processes

Tight control of raw green liquor total titratable alkali (TTA) may be considered an important first step towards improving the overall economic performance of the causticizing process. Dissolving tank control is made difficult by the fact that the unknown smelt flow is highly variable and subject to runoff. High TTA variability negatively impacts operational costs through increased scaling in the dissolver and transfer lines, increased deadload in the liquor cycle, under- and over-liming, increased energy consumption, and increased maintenance. Current practice is to use feedback control to regulate the TTA to a target value through manipulation of weak wash flow while simultaneously keeping dissolver density within acceptable limits. Unfortunately, the amount of variability reduction that can be achieved by feedback control alone is fundamentally limited by the process dynamics. One way to improve upon the situation would be to measure the smelt flow and use it as a feedforward control variable. Direct measurement of smelt flow is not yet possible. The use of an indirect measurement, the dissolver vent stack temperature, is investigated in this paper as a surrogate feedforward variable for dissolving tank TTA control. Mill trials indicate that significant variability reduction in the raw green liquor TTA is possible and that the control improvements carry through to the downstream processes.

FEEDBACK CONTROL OF LH-SECRETION IN THE CASTRATED ADULT MALE MINIATURE PIG

1975 ◽  
Vol 80 (1_Suppla) ◽  
pp. S76
Author(s):  
N. Parvizi ◽  
F. Elsaesser ◽  
D. Smidt ◽  
F. Ellendorff
Keyword(s):  
Feedback Control ◽  
Adult Male ◽  
Miniature Pig ◽  
Lh Secretion
Sign in / Sign up

Export Citation Format

Share Document