Patent attributes
An evaporator includes a refrigerant conduit; and front and rear plates sandwiching the refrigerant conduit, each of the front and rear plates including: a plurality of ice forming columns; a set of first protrusions and a set of second protrusions defined therein, each first protrusion on the front plate and a corresponding first protrusion on the rear plate defining a respective active cavity and each second protrusion on the front plate and a corresponding second protrusion on the rear plate defining a respective passive cavity, the refrigerant conduit extending through each of the active cavities but not any of the passive cavities; and inner flat portions of the front plate and the rear plate facing each other to define respective spaced portions, wherein the active cavities and passive cavities are interspersed and separated by respective inner flat portions so as to define a plurality of ice forming sites.