Motivation

At Portland State University's Healthy Buildings Research Lab, Dr. Gall has been studying the effects of wildfires on human health. One of the complications in doing so is generating a consistent and reliable source of simulated wildfire smoke.

Under the inspiration of a paper written by the EPA, my team was tasked with building a linearly-actuating quartz tube furnace to perform long-running pyrolysis of forest biomass. We had very specific requirements around movement speed, biomass load, temperature, power requirements, budget, and timeline.

Results

We successfully delivered our finished product, within budget, in June 2023. Through the course of the project, we ended up building several subsystems from scratch in order to save time and/or cost, including a thermocouple controller and the entire linear actuator.

My Contributions

While the entire team worked together to build consensus on all parts of the project, my specific focus was on the controls subsystem. I was proud to have designed and printed a custom PCB (using KiCAD and JLPCB) to coordinate between several thermocouple amplifiers and a Teensy microcontroller, encapsulating our temperature measurement system. I also developed much of the layout and code for the system controller, which was Arduino-based. The system controller used a Modbus/RS-485 bridge to communicate with a commercial PID temperature controller from Autonics, coordinated the linear actuator movement through a stepper motor, and responded to user interface controls.

Special Thanks

This project would not have been possible without the tremendous effort from everyone on my team: Mohammed Alzaben, Amir Boumatar, Douglas Herman, Diana Hendricks, and David Woodbury. Thank you to Dr. Elliott Gall, Dr. Alex Hunt, Dr. Jun Jiao, Dr. William Eisenhauer, Kaleb Hood, The PSU EPL, MELT, and Sarah Santucci for the support and guidance along the way.