THERMAL RECEPTACLE WITH PHASE CHANGE MATERIAL

A phase change apparatus has a generally tubular housing with an open upper and lower end and a sidewall having inner and outer surfaces with a chamber defined therein. At least one of the surfaces is convoluted, and a phase change material is disposed in the chamber. The upper end of the generally tubular housing engaged the upper end of an insulated cup. At least one passage is defined between the inner and outer surfaces of the generally tubular housing to allow the flow of liquid when the cup is tilted. The phase change material disposed in the chamber absorbs thermal energy from the liquid and then releases the thermal energy back to the liquid to maintain the temperature of the liquid.