Heater plate assembly

A heater plate assembly for heating with heat retained from an external heat source, comprising:

• a plate housing formed having an internal cavity, said plate housing adapted to be heated by external heat source;
• said plate housing including an upper planar plate and a lower planar plate, said upper and lower plates separated by said internal cavity and enclosed by sidewall plates;
• said upper, lower and sidewall plates formed of impervious metal and secured into a fluid tight enclosure surrounding said internal cavity;
• heat retaining means disposed in said internal cavity of said plate housing for retaining heat from the external source for subsequent retained heating of said plate housing, said heat retaining means including glass beads packed within said internal cavity except for the open spaces between adjacent glass beads in contact with one another;
• said heat retaining means including phenanthrene for binding said glass beads together for enhanced heat retention, and said phenanthrene substantially filling the open spaces between said glass beads;
• heat transfer enhancement means disposed in said internal cavity for enhancement of heat transfer to and from said heat retaining means;
• said heat transfer enhancement means including a heat conductive member in contact with said upper plate, said lower plate and said heat retaining means within said internal cavity;
• said heat conductive member including a corrugated metal plate disposed within said internal cavity in engagement with said upper plate and lower plate of said plate housing;
• and
• vent means in communication with said internal cavity and with said plate housing to permit venting of any gas pressure within said internal cavity during heating of said plate housing.