Patent AT-E40000-T1: [Translated] PLANT FOR COOLING PRODUCTS UNDER VACUUM.

Method of operating an installation for refrigerating products under vacuum, such as lettuce, which installation comprises a closable vessel for the products, one or more vacuum pumps adapted to produce a vacuum in the interior of the vessel, a water vapour condenser (1) disposed in the vessel through which a refrigerant can be passed, and a refrigerating unit comprising a compressor (7), a condenser (9) and a throttle valve (13), disposed outside the vessel and an evaporator being formed by said water vapour condenser (1) disposed in the vessel, whereby a low-pressure separator (3) is provided for liquid and vaporous refrigerant, the suction pipe (6) of the compressor (7) and the outlet pipe (14) of the throttle valve (13), as well as the two pipes (2 and 4) of the water vapour condenser (1), being connected to said separator, while a high-pressure vessel (11) for liquid refrigerant is disposed between the refrigerant condenser (9) and the throttle valve (13), whereby the compressor (7) is brought into action, with the throttle valve (13) open, approximately simultaneously with the vacuum pump or pumps and the throttle valve (13) is closed at reaching the evaporation temperature of the water in the product.