Testing study on desalination role of the gray-white ice in the Bohai Sea by the centrifugal rotational speed

Effect of centrifugal rotational speed on desalination and factors exceeded quality standard of gay-white ice in the Bohai Sea were studied by centrifugal experiments at the laboratory.The experimental results show that the effect of rotational speed variance on the desalination and its efficiency are obvious under the same experiment condition.When the rotational speed arrived at 2 000 r/min,the total salt of the desalted ice decreased basically to the standard value.The rate of desalination of gray-white ice in the Bohai Sea maintained higher level and commonly surpassed 80%~90%.When the centrifugal rotational speed was 3 000~4 000 r/min,the rate of desalination of gray-white ice in the Bohai Sea was maximum and its value was 90.96%.The removal of materials exceeded standard from gray-white ice was influenced in varying degrees by the variations in the centrifugal rotational speed. The sulfate content changed maximally and decreased by 73.19%~96.52%.The salinity also more decreased and had less decreased range than sulfate,the range was 71.86%~93.55%.pH value was not deteriorative after desalination and it maintained about 715.Therefore centrifugal rotational speed is one of major controlling parameters in the centrifugal desalting process of gray-white ice in the Bohai Sea.After gray-white ice in the Bohai Sea were desalted,such quality factors as salinity of desalted ice fulfil the needs of water for the industry and agriculture production and the people's living.