北京市果品公司拥有六座冷库,总容量三万五千吨,均以氨做为制冷剂。这些冷库年总耗水量达一百多万吨,因而在北京也可算得上是用水大户。主要用水设备是制冷系统中的氨压缩机和冷凝器。八七年以前,我公司冷库所用冷却水虽为一次排放或回灌,但冷库降温时日用水量较大,约每小时八十吨。因此,用水设备存在结碱现象,每两到三年就需停产用酸除垢一次。八七年以后,按北京市节水办要求,果品公司所属的六个冷库逐步建成了冷却水循环系统,大大节约了用水。但随之产生了一个新问题:由于冷却水循环使 Beijing Fruit Company has six cold storage, with a total capacity of 35,000 tons, all with ammonia as a refrigerant. The total annual water consumption of these cold storage reaches more than one million tons, so in Beijing can be regarded as a large water user. The main water equipment is the ammonia compressor and condenser in the refrigeration system. Before 1987, although the cooling water used by our company was discharged or recharged, the daily water consumption of the cold storage was relatively large, about 80 tons per hour. Therefore, the existence of water equipment alkalization phenomenon, every two to three years to stop production with acid descaling once. After 1987, according to the requirements of Beijing Water Saving Office, the cooling water circulation system has been gradually built up in the six cold stores owned by the fruit company, which has greatly saved water. However, a new problem ensued: due to the cooling water circulation