Practical Process Problems Solving and Optimization in Real

Avihu Hiram, HIRAM - Process Control, Haifa, Israel


This presentation is based on real project with the local industry – improving existing Phosphoric Acid Concentration Unit Operation – part of a Phosphoric Acid production plant.
The success of this work was achieved thanks to excellent cooperation with all client functions.

A thorough involvement with the plant operating staff enabled unconventional (than) actions to take the mission to remarkable success.
Project had three main phases:

• Identifying operation flaw – local over heating which caused frequent production halt – and applying a simple and immediate solution.
  
• Additional improvements based on better process dynamics understanding:
  • Adding weighted correction to the evaporation temperature control to compensate for pressure (vacuum) changes.
  • Understanding the roll of "Evaporator ∆T" and improve process behavior accordingly.
• Developing the "Operation Shell" approach. Few control actions are responsible for more than one controlled variable each and proper considerations have to be taken to keep the whole process with in the "Operation Shell". This was implemented using advanced control techniques. Using the "Operation Shell" approach enabled us to make out where are we at any given instance of operation, identify the current limiting factor and if there are any degree of freedom to optimize operation.
  

The demonstrated approach can easily be applied to any process with similar characteristics.