Difference between revisions of "PH Loop"

Revision as of 16:33, 28 November 2011

The pH control rig

PH control is a difficult problem due to the highly non-linear nature of the system. The steep slope of the titration curve around the pH = 7 point amplifies pH variations for even small base/acid addition variations. The pH control rig in the PMC lab illustrates that pH control is by no means impossible (albeit on a laboratory scale).

Current/Previous projects

1999

F.J. Botha, Ondersoek van die Dinamiese Gedrag van Sisteme waar pH Gemeet en Beheer word {Investigation of the Dynamic Behaviour of Systems where pH is Measured and Controlled}
[Hard copy of report available in pH rig folder]

2003

T. Leeuw & G. Mascini, pH Rig 2003 - CPL780 Process Control Laboratory
Report | Project files

2005

A.J. Swanepoel & M. Swanepoel (Botha), Model Based Control Laboratory, pH Control
Report | Project files

2007

C. Steyn, Fuzzy Logic Rule-Based Controller Design, Neutralization of Strong Acid with Strong Base
Report | Project files

2009

A.H. Campher, Maintenance, Modelling and Control of the pH-control Rig
Report | Project files

2010

A.B. De Jongh, Control of a pH neutralisation system using Gain Scheduling
Report | Project files

2011 (Current)

S.C. Burd, Non-Linear Model Predictive Control of a pH Neutralization Process
/Report | Project files

Documentation

Large scale renaming of instruments, valves and tanks is being done. This renders all previous rig diagrams obsolete. Only 2009-updated diagrams should henceforth be used.

Piping & Instrumentation diagrams

.VSD (Visio) | .PDF

Wiring diagrams

.VSD (Visio) | .PDF

Rig maintenance

The maintenance of the pH rig is documented here.