From Waste to Power: Pulsing Biosludge Atomization for Efficient Energy Conversion

Researcher: Daniel Wilson | Faculty Advisor: Wayne Strasser

We live in a world with ever-increasing energy needs and waste production. To address both issues, we are developing new technology to efficiently convert human waste to usable energy. Our method enables direct injection of highly concentrated biosludge (human waste sludge) into energy-harvesting equipment for combustion. Compared to other methods of energy conversion that require dilution and/or drying, direct injection of a concentrated biosludge increases conversion efficiency, reduces water usage, and reduces fossil fuel emissions. Atomization of the biosludge (breakup of the bulk sludge into smaller droplets) is important for combustion, as a high surface area to volume ratio is desired. We use computer simulations to model a biosludge injector design that uses a steam flow to assist in atomizing the biosludge. Difficulties arise because the viscosity, or thickness, of biosludge varies widely. If viscosity levels are too high, the pump will have difficulty moving the biosludge through the injector, and atomization quality will suffer. To overcome this problem, we added controllers to the injector to create a “smart atomization” system that automatically adjusts for dynamically changing biosludge viscosity. We demonstrate the efficacy of this “smart atomization” system by maintaining efficient atomization with a simulated 100-fold increase in biosludge viscosity.

High-Velocity Nasal Insufflation Study

Researcher: Eli Best | Faculty Advisor: Wayne Strasser

Through research, we seek to provide tools for the medical and scholarly communities to use when considering a relatively new respiratory therapy technology—High-Velocity Nasal Insufflation (HVNI) equipment. We use computational fluid dynamics, image processing software, and medical testing procedures to gain confidence in how the HVNI equipment interacts with a patient’s respiratory system. Using this information, practitioners and future researchers can better estimate the upper and lower bounds of effectiveness for this technology. An accurate upper bound could save lives, while an accurate lower bound could improve patient comfort and decrease the cost of care. Human trials with healthy volunteers under respiratory stress are used to simulate the effects of the equipment on unhealthy patients.

Mucus Emissions During Coughing and Sneezing

Researcher: Andres Del Valle | Faculty Advisor: Wayne Strasser

In a study by Yang et al. (2007) an aerodynamic particle sizer and a Scanning Mobility Particle Sizer were used to measure the size distribution of droplets and their nuclei. The APS can measure particle sizes ranging from 0.6 μm to 30 μm, and the SPMS can measure particle sizes ranging from 0.02 μm to 0.6 μm. An air velocity meter was employed to measure the cough velocity for calculating mean cough flow rate averaged over the total duration of the cough. In a study by Almstrand et al. (2009 and 2010) and Larson et al. (2017), PExA instrument and method were used to measure particle size and flow rate. The PExA set up is: ultrasound based flowmeter, an inertial impactor to measure particle size and mass, and an optical particle counter. This method measures particles from 0.3 μm to 2 μm in size. Spirometry was performed using a flow-based computer-assisted spirometer with the “Spirometry/Flow-Volume” software. In an article by John V. Fahy and Burton F. Dickey (2010) mucus is 97% water and 3% solids. In a review by Ohar et al. (2019) mucus is 95-97% water 2-5% mucin. In a study by Sheehan et al. (2000) MUC 5AC was isolated and observed. In a study by Hughes et al. (2019) MUC 5B is isolated and observed In a study by Kirham et al. (2002) the mass of MUC 5AC and MUC 5B in mucus is found. In a study by Anderson et al. (2015) the percent of mucin in mucus is found to very depending on one’s health. Mass flow of mucus can range from 2.28*10^-12 kg/min to 5.23*10^-11 kg/min.