Chocolate Cooler

thingiverse

The chocolate extruder's printed layers must be rapidly cooled before they can support subsequent layers, necessitating instant cooling. A Ranque-Hilsch effect vortex tube cooler inspired by a Thingiverse design (http://www.thingiverse.com/thing:8114) is the solution. This cooler uses an -15 degree Celsius air stream to instantly cool 3D printed chocolate. Vortex tubes are industry-standard for spot cooling applications, using compressed air at 5 bar to produce cold air at one end and hot air at the other. Links to vortex cooling with chocolate are available at Exeter University (http://www.exeter.ac.uk/news/research/title_145191_en.html) and Exair (http://blog.exair.com/2011/11/01/refrigerated-air-from-compressed-air/). Before starting, ensure an air compressor capable of delivering 4 to 5 bar is available. Print the required components, including the vortex_generator.stl (which needs support removal) and the hot end composed of two parts requiring Bison epoxy glue and an M3 nut. Adjust cooling efficiency by controlling air escape at both ends. The brass or aluminum vortex tube dimensions are 8mm OD x 6mm ID x 180mm, with a crucial length-to-inner diameter ratio between 20 and 55. Attach a metal tube to the cold end for hose ducting close to the chocolate nozzle.