Patent ID: 6526767
Filing Date: 2003-03-04
Classification: F25D

Abstract:
An automatic defrost system for a refrigerating device, whose cabinet (1) comprises a freezing compartment (2) and a refrigerating compartment (3), a refrigeration circuit including a condenser (20) and an evaporator (10), and a refrigeration forced air circuit comprising said compartments (2 and 3) and the evaporator (10), characterized in that it further comprises a defrost air circuit (30) through which the defrost air flows by natural convection and having: a first circuit portion (31), through which flows a certain defrost airflow; a second circuit portion (32) receiving the defrost airflow from the first circuit portion (31) and positioned adjacent to the condenser (20), in order to exchange heat with the latter and heat the defrost airflow; a third circuit portion (33), which selectively receives, from the second circuit portion (32), the defrost airflow, and which is positioned adjacent to the evaporator (10), so as to be in direct contact with the latter and heat it when the refrigerating device is under a defrost condition, and conducting the defrost airflow to the first circuit portion (31); and a valve means (40), which selectively permits the passage of the defrost airflow from the second circuit portion (32) to the third circuit portion (33), upon occurrence of a certain ice formation condition in the evaporator, and blocks said passage of defrost airflow, upon completion of the defrost in the evaporator (10).