Modifying Hospital Sterilization Boiler for Countries Overseas Justin Albrethsen 1 , Jacob Gorton 1 , James Gruss 2 , Michael Kibbe 1 , Jennifer Moran 2 Marco Orlando 2 , Thomas Roache 3 Mechanical Engineering 1 , Software Engineering 2 , Industrial Engineering 3 Problem Statement The stakeholder, Christian Hospitals Overseas Secure Equipment Needs (CHOSEN), requires a more automated steam generation system. This system will be implement. In medical sterilizers to be used in developing countries. Vision Statement To design a boiler system that will automate both pressure and water level using minimal electricity. Design Requirements Minimal electricity and technical knowledge for operation Capable of using variable heat sources Constant boiler tank pressure of 80 ± 10 psi Tank must maintain a water-to-steam ratio of approximately 1:1 Automatic pressure regulation Automatic water level regulation Sight glass must have fittings greater than NPS 1/2, have a drain greater than 1/4”, and 1” below the lowest allowable water level must be visible (ASME) Temperature gauge to quickly identify internal temperature Pressure gauge to quickly identify internal pressure Check valve and stop value must be present between the water pump and boiler tank A drain value of at least NPS 3/4 must be present near the bottom of the tank (ASME) Tank Schematic Pressure Regulation Solution Regulator valve must be calibrated to stay within pressure variance When pressure limit is reached, valve will open to relieve excess pressure Steam generation will keep pressure above lower limit Failsafe emergency valve will open when pressure reaches 100 psi and will stay open until system is reset. Water Level Maintenance Solution Water level will be maintained through a conductive probe apparatus, an Arduino Uno microcontroller, and an electric pump The pump motor will be controlled by a solid state relay, which will be protected by a circuit breaker Three probes will be used: a 5V live probe, a high level probe, and a low level probe As water contacts a sensing probe, a circuit is completed which sends an analog signal to the Arduino As water falls below the low level probe, the pump will start; as water contacts the high level probe, the pump will stop Full System Diagram Side View of Tank 1 Side View of Tank 2 Next Steps Acknowledgements The system has been tested and it is verified that the regulator valve will keep the pressure in the tank within the allowable 80 ± 10 psi range. It was also verified that the probes maintained the water level automatically. Unfortunately, the failsafe emergency valve did not open even when reaching a psi of 120. Once this issue is resolved, CHOSEN will be able to send these systems to developing countries. SEECS, Scholars of Excellence in Engineering and Computer Science, is a scholarship program funded by a National Science Foundation S-STEM Award #1153250 Pictured here is a view of the 3 water sensing probes and their connections to the Arduino microcontroller Pictured here is a view of sight glass