ECHM 451 Chemical Engineering Process Dynamics and Control

1. ECHM 451Chemical EngineeringProcess Dynamics and Control Spring, 2014 REID 104

2. What is Process Control? • Techniques and technology to control a process. • Example: light switch • Example: coffee maker • This class will focus on automated control

3. About me… • Office: COBL 310 • Phone: 406-994-7902 • Email: jeff.heys@gmail.com • Office hours: • Tuesday 11:00am – 12:00pm • Thursday 1:00pm – 2:30pm • Open office policy, but focus on TTh

4. About this class • Meet twice per week on Tuesday and Thursday. • Scheduled time 9:25-10:40 (typically less) • http://www.coe.montana.edu/jeffrey.heys/web451 • “Typical class”…. Lectures, homework, 2 exams including the final, and a project • Lecture capture?

5. History • 1995: Ron Larsen took a sabbatical with Dow focused on process control • 1996: I took the course from Dr. Larsen the first time he taught it • 1996 – 2011: Dr. Larsen refined and improved the course and wrote a textbook along the way. • 2011-12: Dr. Larsen promoted to associate provost

6. 2013 • I’m teaching this course for the thirdtime (some experience at Stone Container). • We will use Dr. Larsen’s book (pick up in main office…$14.50) • Read the syllabus and schedule • Homework policy (boxes, staple, 1 or 2 per page, etc…) • Check your MSU email account frequently

7. Chapter 1 • Example #1: Thermostat (On/Off control with set points (SP)) • Example #2: Cruise control (proportional control) • Determining is difficult

8. Why? • Convenience (and lower labor costs) • Safety (many industrial accidents could have been prevented with better process controls) • Consistent quality (computers are just better at mundane details)

9. Why? • Most chemical and biological engineers are not process control experts, but they need to understand the basics! • Production engineering: responsible for day-to-day operations. Need to understand process controls to deal with daily issues. • Process engineer: longer term view toward continuous process improvement…these improvements often involve new or modified process controls.

10. Specialists • Some chemical and biological engineers become process control engineers – focus on improving process control systems and implementing standard systems • Even fewer become process control specialists – implement solutions for specialized, nonstandard, control situations.

11. Types of Process Controls • Manual control (open loop) • On/Off control (closed feedback loop) • PID control (chapters 2-9) (closed feedback loop) • Dynamic model-based control (closed feedforwardloop) • Empirical models (e.g., cold shower) • Phenomenological models

12. This book… • Focus is on information needed by process and production engineers (i.e., not specialists) • Other books focus on process modeling and Laplace transforms first, and then they discuss PID controls for those processes (and the result are engineers that cannot tune a controller without a model).

13. Larsen vs. Luyben, Riggs, etc. Traditional Larsen Learn about hardware/software (briefly) Learn basics for analysis of hardware/software Process Modeling Convert model to Laplace space Analysis of hardware/software in Laplace space • Process Modeling • Convert model to Laplace space • Learn about hardware/software (briefly) • Analysis of hardware/software in Laplace space

14. Basic Control System • Oil heater that uses steam

15. Basic Control System • #1 – we need a sensor (and we cannot measure everything, like entropy or fugacity)

16. Basic Control System • #2 – we need a controller (e.g., PID controller)

17. Basic Control System • #3 – we need something to control (and we cannot control everything like steam T and P)