To make it possible to efficiently operate by early sensing the frost clogging in a cold storage chamber, and defrosting without necessity of water in case of defrosting a cold storage type cold insulation box.
The cold storage type cold insulation box comprises a heat insulation partition wall 4 provided in a cold insulation box body 1 to partition into a cold insulation chamber and a cold storage chamber and provided with a cold air suction port and cold air discharge port, a cooling tube 8 circulated in the cold storage chamber, a cold storage plate 7 for enclosing cold storage agent, and a cold air circulating fan 10. An electric heater 19 is disposed near the plate 7. Dampers 17f for interrupting the circulation of the cold air to the suction port and discharge port are provided. A flapper 18 for straightening the air circulating in the storage chamber is provided at a mouth ring attached to the fan 10. At the time of defrosting, the fan 10 is reversely rotated to supply the air in the opposite direction of an arrow, both the dampers 17f are closed by the flow, and the flapper 18 of the ring is also closed to circulate only the air in the storage chamber, thereby defrosting it by the hot air from the heater 19.
IGAWA MINOBU
WATANABE TAKASHI
