Difference between revisions of "Coil Drink Cooler"

Revision as of 17:00, 2 August 2010

Overview

Inspiration came from the Six Legged Groove Machine's portable rave party seen at Phreaknic, and the crazy steampunk contraptions people are building for events like DragonCon. Most of them look interesting, some even dispense liquid, but none of them seem to actually cool the contents.

Proof of Concept

• YouTube Video

Worked well. Cooled liquids as expected. One thing we may have to watch out for is acidic drinks eating at the copper and creating a metallic taste. Can be easily reworked into a MK I version. Steampunk theme will be difficult due to the size and shape of the containers. Cyberpunk/Rave theme would work excellently.

MK I

In order to enhance the party atmosphere a fluorescent material should be added to the coolant so that it glows as it circulates through the clear plastic tubing. The quinine in tonic water glows a blueish-white under a blacklight. Vodka and tonic water combined in the coolant tank with dry ice will give us a very cold vodka tonic that is constantly being recarbonated. This will bring the total number of serveable drinks to three.

Safety Improvement

After building the proof of concept, we learned that acidic drinks and copper don't mix well. The acid breaks off copper molecules into the liquid intended for drinking, and could cause heavy metal poisoning over time. We're going to shoot for stainless steel tubing next.

Materials

• 10Ft 1/4 Inch Copper Tubing (10Ft / Coil) (Home Depot, $12 for 20 ft) (DON'T DO THIS: Acids found in soft drinks are corrosive to copper.)
  • 25ft 1/4" Stainless Steel Tubing (eBay, $35 for 25ft)
    • Preauxphoto has stainless steel tubing for us, haven't found out the diameter yet
• Cylinder for shaping the coil (we used a can of baked beans)
• Plastic Drink Reservoir (1 per coil) (We purchased two 1 gallon Snapware containers from Target, $6/each)
• Plastic Coolant Reservoir (We purchased a square 2.5 Gallon container from Wal-Mart, $6)
• Drill and Drill Bits (For drilling holes in the plastic containers)
• Hack Saw (for cutting copper tubing)
• Fish Tank Water pump (DC pump with solar panel $20. 2.5 ft lift, 42 GPH. Also available is a 500 GPH bilge pump for $17. Way more than we need)
• 3/8 inch vinyl tubing (Home Depot, $4)
• Dry Ice (optional. Must be 18 to purchase. Wal-mart, $6/small bag)
• Alice frame (Army Surplus Store, $20-30 depending on whether you get the straps or not)

MK I.V

This is a redesign of the MK I based off of Phreaknic field trials. This version will let me test out new features before building the 2.0 version

Needed changes:

• Modular drink containers for ease of cleaning (dishwasher safe)
• All systems completely separate from each other, ie. cooling pump system, drink module, coolant tank, and dispensing system all separate
• All serviceable hardware should be on the outside of the pack
• Serviceable hardware should be able to be worked on by another person without removing the pack.
• Smaller coolant tank
• Pressurized dispensing system
• Rigidly mounted cooling coils
• Smaller diameter cooling coils
• Screw-on water-tight lid for drink modules
• Improved electrical wiring layout
• Taps need a narrower spray pattern
• Drink modules need a port in the lid for quick filling

Proposed extra features:

• A heat exchanger instead of an open cooling system to prevent the pump from freezing.
• Hot swappable drink modules
• Reverseable pumps for one-man in-the-field refills
• Small portable charger for the batteries
• Status lights and master pump control panel
• Insulation (may compromise dishwasher safeness)
• Sight glass or some method of determining drink levels
• Improve battery life with larger batteries

Materials

• Pumps
  • http://www.lightobject.com/7LMin-mini-DC-Water-Pump-Ideal-for-HHO-and-CPU-Cooling-P156.aspx
    • Come in 4mm, 3 lpm and 8.6mm, 7 lpm versions
    • About half the cost of the current coolant pump
    • Can be used for dispensing and cooling
    • Three pumps after shipping is $41
      • 1 pump for coolant, 2 pumps for drink dispensing

• Drink Modules
  • 6 x 18 inch pvc pipe with a cap permanently fixed on one end and screwed onto the other (use 4" diameter instead)
  • Cooling coil fixed to the screw-on lid
  • Two ports for coolant in lid
  • One port for dispensing on the top
    • Tube goes from bottom of the interior to an interface embedded in the lid
    • Dispenser pump interfaces to the interface on the exterior of the lid
  • Flange with screw-on cap (2 inch diameter?) for quick mixing of refills
  • Sight glass to determine drink levels

• Coolant system
  • 6 inch pvc pipe tee with permanently mounted pipe caps and a screw on lid
  • Pressure valve to prevent explosion from CO2 buildup
  • Fixed heat exchanger coil mounted inside (maybe)
  • Interface to coolant pumps

• Dispensing System
  • Pony keg taps
    • http://www.kegkits.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=PonyTap&Category_Code=HHKT
  • Interface to dispensing pumps

MK II

This will be the steampunk themed version. The clear plastic tanks will be replaced by cylindrical tanks made of clear acrylic or pvc pipe. The tanks should be 6 inches across and 18 inches long. On the coolant tank will be a vent stack shaped like a chimney for the vapors from the dry ice. The overall look will be similar to a WWII flamethrower.

Working Dates

• Began working on this at the hackerspace meetup, 9/17 - 9/18