COLD CAN CRUSHER
This was a fun group project I worked on for my senior design course. The purpose was to identify a consumer need and develop a product to solve this need. Our group chose to address the need for a product that could quickly cool a canned beverage while also crushing the can for easy recycling.
Functional requirements:
Prototype must be cost-effective ~$600
Easy to use interface
Consumer setup time should be less than 10 minutes
At most 2 controls the user must focus on during operation
Fully crush can
Cool beverage to less than 44°F
CRUSHING MECHANISM
We initially decided to have a manual operation for the crushing mechanism and determined buying an existing can crusher and modifying it would be the most cost effective solution for our prototype. An angled pipe was welded into the bottom to act as a puncture for the can as well as a drain to the cooling system.
COOLING SYSTEM
A 3/16" copper pipe submerged in ice water was used for our cooling mechanism. We calculated the length of piping required to cool a flowing beverage from room temperature to 35°F. Then we calculated the number of coils needed to fit the piping into our styrofoam cooling chamber. Experimental testing was also conducted to confirm the actual temperature change and flow duration of the liquid, which turned out to be much longer than expected.
ALPHA PROTOTYPE
Our first prototype was successful in crushing a can and cooling the beverage to the appropriate temperature, however it did have some issues to be improved upon. Gravity draining was not efficient due to air bubbles and foam causing the beverage flow to stop and require some manual assistance. The crushing mechanism was also not sealed well, so some spilling occurred. For the Beta prototype, we are looking into adding a pump to assist fluid flow, as well as an actuator to allow smoother and hands free operation.
REDESIGNED CRUSHING CHAMBER
To create a fully sealed crushing chamber, we used PVC pipe and cut out a door for inserting cans. This design allowed us to mount the actuator in the upper section of the PVC pipe, hidden from view. We welded together mounting and crushing plates for the actuator out of sheet metal. The crushing plate rubbed against the sides of the chamber during operation, so we used thick foam inserts to center the actuator inside the piping.
IMPROVED PUNCTURE AND DRAIN
We fabricated a sharper puncture plate with extra holes to speed up draining. a pump small enough to fit inside the PVC with minimal modification was found and a funnel to feed all the liquid into the pump was 3D printed. Silicon sealant was used to mount the funnel to the PVC and seal any other connections to the drain.
COOLING CHAMBER MODIFICATIONS
Since flow was an issue, we increased our copper coil to a 1/4" ID and decreased the number of coils to achieve similar cooling capabilities. A more visually appealing and properly sized steel keg was used for the chamber and was modified to provide a removable lid for refilling the cooling medium. Window weather stripping was used to provide better thermal sealing of the lid.
EXPERIMENTAL TESTING
Our new crushing chamber design and actuator allowed us to accommodate larger canned beverages, up to 24 oz. We used a variety of can sizes to confirm the prototype could crush every can to less than 2 inches tall, as well as cool all beverages to 45°F.
BETA PROTOTYPE
Our final prototype performed much more smoothly than our initial design. The new design for the crushing chamber, featuring the actuator and pump, allowed:
On/Off switch for easy hands-free operation
Very consistent results
Much lighter and compact frame
Minimal setup for the user
We determined the prototype could cool up to 30 12oz cans before the ice water needs to be replaced, and added a Y-shaped drain for the ability to mix in other drinks and provide an easy inlet to flush and clean the device.
FINAL REPORT
To conclude our design project, we wrote a technical report detailing the evolution of our design throughout the semester as well as all calculations and testing performed to achieve our functional prototype. Along with the report, we created engineering drawings for each component of our design and an assembly view of the final prototype.