This is a CO2 powered rapid drink cooler. This project was originally intended to be small but it quickly grew in proportions due to lack of cooling power. It uses the decompression and fast flow rate of released CO2 to cool down a drink rapidly and without diluting the drink. It is really quite useless since it works about the same as ice or ice substitutes but it was a fun build. It isn't practical because it takes too much time and therefore CO2 to cool a drink.
1 industrial grade 20lb. beverage CO2 tank (pick one up at a local welding air supply shop)
10' of 1/4" copper tubing
couple of fittings to get your CO2 tank to your 1/4" copper tubing (I went to Home Depot and they helped me find what I needed, some kind of compression fitting)
Submersible temperature sensor
Jumper wires, hot glue, 3d printed cube for looks, etc, etc
Step 1: Wrap and Attach Coil
First find something with a diameter that will fit into the cup of your choice, then carefully wrap the copper tubing around it to make a coil. Then you need to connect your newly made copper coil to your CO2 tank with your fittings. You should now be able to release the CO2 and cool a drink by holding the drink under the coil (you should probably do this outside or in a well ventilated place).
Step 2: Create Temperature Sensor
I decided to add a temperature sensor to my drink chiller so that I know when my drink is cold. I hooked up a submersible temperature sensor (one of these was laying around the lab https://labjack.com/accessories/ei1022-temperature-probe). I have attached my code to make this work. It detects the temperature and changes the color of a neopixel from red to blue as the drink gets colder. The neopixel turns completely blue when the drink reaches 50 degrees F. The light is underneath a 3d printed ice cube to make it more pleasing to the eyes.
Step 3: Put It in a Box
I then decided to put all of the electronics into a foam core box so that it looks nicer. I made a box using foam core and hot glue and cut a hole in each end for the power jack and temperature sensor. I then glued the ice cube to the box and started cooling drinks. I cooled a glass of water from 104 degrees F to 39 degrees F in around 2 minutes. It works relatively well, it's just not too practical.