Hitachi Appliances Inc. has announced the “R-X6000 refrigerator which can reduce air pressure in the chilled room to 0.7 atm. The Hitachi R-X6000 forms a vacuum and decreases the oxygen density in the chilled room, preventing the DHAs, vitamins and amino acids in food items from oxidizing, the company said. To form a vacuum in the chilled room, Hitachi Appliances developed a high-strength chilled room and vacuum pump. The upper and front surfaces of the room are under the loads of 300 kg and 150 kg, respectively, because the air pressure in the room can be as low as 0.7 atm. Therefore, the upper surface is made of 8-mm-thick tempered glass, and the bottom and side surfaces, which are made of plastic, are reinforced with 1.6-mm-think steel plates.
The front door of the chilled room is sealed by a rubber packing and pressed to the room by a “lock handle” in front of the door. The chilled room was designed on the assumption that it is used 10 times a day for 10 years, so it can be opened and closed about 40,000 times. The Hitachi refrigerator R-X6000 has a rated inner volume of 601 L and will be available from Sept. 24, 2007 for approximately 310,000 yen ($ 2,724). The R-X6000 will also be released in Taiwan on almost the same day as in Japan.
