1. P13631: Gravity Fed Flow Process Control Teaching Aid An RIT education couples theory in lecture with practical application in lab. In the past, carts have been built by senior design groups to demonstrate lecture concepts. This project combines the dynamics of a gravity drained tank with LabVIEW to teach process control. The team progressed from theoretical design and planning to implementation over the course of 7 months. The final result is a functioning cart to teach process control. Project details can be found at our website: http://edge.rit.edu/edge/P13631/public/Home IntroductionCart Layout Y(s) = output of process Y s (s) ­ = set point of process G d = derivative transfer function D(s) = disturbance output G c = controller transfer function G a = valve transfer function G p = process transfer function G s = level or flow transmitter transfer function. G c = controller transfer function K c = controller gain from tuning K a K p = K c ; the actuator and process gains Τ c = controller time constant Τ v = valve time constant S = transfer function variable in the Laplace transform space τ I = integration time constant K p = process time constant Combining all process dynamics yields: Draining a tank is a non-integrating (or self- regulating) process. A constant liquid level corresponds with an inlet flow set to match the outlet flow via the control valves on the cart. This is conveyed through equations below: Theory Safety and ergonomics Student learning Transportability Ease of maintenance Minimal water use Minimal cost Interface with LabVIEW Customer Needs Design Process The group chose the line pressure cart that used a sink faucet to supply water at approximately 45 psi. Based on the Pugh chart and risk analysis, that design had the fewest number of risks. Leaf table to increase student workspace Aluminum bracketing to decrease weight and increase mobility Wheels and brakes to increase mobility and practicality Cart Features Functionality Testing Process constants Gain (inches/percent open) Time constant (min) Control Valve 10.915.37 Control Valve 21.67.45 Safety TestingResult Center of gravityPass Stress and deflection Pass Electricity grounding Pass Testing Results Conclusions and Recommendations The final cart meets customer needs and can be used by students to safely learn about process control. Improvements for the future include: Reducing water use Install a pump to reroute water to supply instead of drain. Install an additional holding tank for water with a recirculation pump. Testing time to complete lab procedure Conduct a time trial with 4 th year Chemical Engineering students and the lab manual to confirm each day takes three hours to complete. Team Members (left to right): Lead Engineer: James Brinkerhoff, ChE Project Manager: Christopher Kulbago, ChE Fluids Specialist: Lauren Pahls, ChE Team Facilitator: Sarah Salmon, ChE Electrical Lead: Ted Rakiewicz, EE Mechanical Lead: Patrick O’Connell, ME This project was made possible by our faculty guide, Steve Possanza, our customer, Dr. Richter, our process controls professor, Dr. Sanchez, and the Chemical Engineering Department Lab Technician, Paul Gregorius.