| 摘要 |
1,216,414. Refrigerators; defrosting. G. BAUKNECHT, G. BAUKNECHT and G. BAUKNECHT, [trading as GOTTLOB BAUKNECHT ELEKTROMOTORENBAU]. 7 Feb., 1968 [14 Nov., 1967; 18 Jan., 1968], No. 5997/68. Heading F4H. In a refrigerator having higher and low temperature compartments 2, 3 cooled by respective evaporators 9, 5, the evaporators operate at substantially the same temperature, evaporator 9 being located in a closed, gasfilled chamber one wall of which has a surface which adjoins the high temperature compartment and has a temperature higher than that of the evaporator. As shown in Fig. 5 (a plan view) the evaporator 9 is disposed in a U- shaped air-filled chamber 10 having a wall 11 which in part defines the compartment 2, heat being transferred from the compartment to the evaporator through wall 11 and by conduction and convection in the air within chamber 10. The temperature difference between wall 11 and the evaporator is preferably between 10 and 35‹ C. and the wall preferably reaches a defrosting temperature in each inoperative period of the refrigeration system. Thermostatic control of the latter may be effected in accordance with the temperature of wall 11. As shown in Fig. 1, the evaporators are serially connected, an accumulator 18 is provided between the outlet of evaporator 5 and the inlet of evaporator 9 and evaporator 5 is supplied with refrigerant by a capillary tube 16 which is in heat exchange with part of the refrigerant path through evaporator 9. Thus, the warm refrigerant in the capillary tube gives up heat to evaporator 9 in each inoperative period of the refigeration system to assist in defrosting wall 11. A cold accumulator in the form of a liquid-filled flexible envelope is provided above the top of evaporator 5 (Fig. 3, not shown). The wall 11 may be thermally insulated (Figs. 13 and 14, not shown), in which case evaporator 9 may contact the wall (Fig. 14), or its thickness may vary from a maximum adjacent each pass of the evaporator coil to a minimum mid-way between adjacent passes of the coil (Fig. 10, not shown). In the latter embodiment a fan is provided for circulating the air in chamber 10. The temperature of the wall of the chamber may be controlled by thermally responsive means which vary the spacing of the evaporator from the wall (Fig. 12, not shown). |
