Nine Control Fundamentals

by | Feb 12, 2007 | Services, Consulting & Training

Jim Cahill

Chief Blogger, Editor

I came across the following nine control fundamentals according to Mark Coughran, a consultant on Emerson’s Advanced Applied Technology team. These are based up his years of experience working with process manufacturers to optimize their performance. You may recall Mark from earlier posts on planning plant turnarounds and turbomachinery pressure control.

His fundamentals include:

  1. Make the process as linear as possible
  2. Minimize dead time
  3. Choose the PID controller to compensate for the process
  4. Avoid resonance or amplification of disturbances
  5. Use process capacity to absorb variability
  6. Decouple the interactions by tuning if possible
  7. Help the PID feedback controller with control strategy
  8. Cascade, ratio, feedforward; a.k.a. advanced regulatory controls
  9. Use Fuzzy, Neural, MPC if the above are insufficient

Although there is a lot behind each one, it’s a way to think through the process of solving control performance issues.

Mark cited an example of a Good Automated Manufacturing Practice (GAMP) facility with eight reactors. All of the controls cycled strongly. As a result, steam was being wasted on the up cycle, and cooling water was being wasted on the down cycle. Thinking through the control fundamentals above, Mark recommended changes in the master controller parameters including tuning, jacket controller tuning, split range strategy, and control valve calibrations.

By implementing these changes on three of the eight reactors steam usage for the facility was reduced 10% reducing the plant’s energy bills.

Submit a Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Submit a Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Subscribe for Updates

Follow Us

We invite you to follow us on Facebook, LinkedIn, Twitter and YouTube to keep up to date on all the latest news, events and innovations to help you take on and solve your toughest challenges.

Want to re-purpose, reuse or translate content?

Please do, Just link back to the post and send us a quick note so we can share your work. Thanks!

Our Global Community

Emerson Exchange 365

The opinions expressed here are the personal opinions of the authors. Content published here is not read or approved by Emerson before it is posted and does not necessarily represent the views and opinions of Emerson.