SOAR Vending
SOAR Vending is developing a workout supplement vending machine for use in fitness centers. As our client, my capstone team developed a new storage hopper and dispensing mechanism for accurate use with different types of powders.
Final Prototype
After initial research, the team decided to design two prototypes to determine which features from each should be included in the final design. The first prototype utilized compressed air to fluidize the powder for consistent flow. The air is directed to the outer edge of the hopper by the yellow, black, orange, and red parts. The use of a cone valve (blue) lifted by a linear actuator (green) at the bottom allows for accurate dispensing.
Power Fluidization Cross-section
Although the powder fluidization prototype functioned properly with lighter protein powders, it struggled with heavier, stickier powders. Additionally, because the design was intended to use a single air inlet for 12 different hoppers, it experienced issues with inlet clogging, powder saltation, and cross-contamination. The team ultimately decided to move forward with the other design.
Powder Fluidization Dispensing
The second prototype used vertically stacked blades and a wire-mesh to agitate and dispense powder similar to a flour sifter. It features a hex axle that turns mixing blades throughout the hopper to lift and agitate the powder. The bottom-most blade is oriented to push powder downwards through a wire mesh into a funnel lined with vibration motors. The blades have the angle of repose for the worst-case powder which was determined by flowability testing. There is a spring loaded cover to keep powder from releasing when the hopper is in motion.
Mixing Blade Bottom Cross-section
Because the axle was secured by a bearing in the lid and exposed above the hopper, a single external motor and gear system could be used for all 12 hoppers. Additionally, the lid has a compartment for silica gel packets to keep stored powders dry.
Mixing Blade Top Cross-section
After gathering dispensing data, the prototype was optimized for different powders by using heat maps. For each powder, the system was able to dispense a full 30 grams serving in under 10 seconds within 0.5 gram precision.
Naked Pea Optimization Heat Map
