The Theory And Experimental Analyses On The Airlift

There are very abundant resources in the ocean of our country, which include iron, manganese, titanium , cobalt, gold, silver, petroleum and so on. .so mining the ocean resources has been an urgent mission. However exploiting the mineral resources in the ocean bed, we have to transport it from the ocean bed under the water several thousands meters to surface, which becomes an important task that must be solved. On the other hand how to clean the a lot of sand and silt under the three gorges(Sanxia) reservoir region that has been another question solved. How to find a solve method and theory has become an urgency problem.We aim at above problems, based on the experimental research success we have done, We did some theory and experimental research on how to clean the scruff whose densityρ= 5×10~3 kg /m~3 is below the water surface 9 meters, which established the academic foundation for the future transporting and lifting iron sand. So the task has the important academic and practical significance. The author analyzed the following aspects according to the lifting scruff.Firstly, introducing the air-lift principle and deducing characteristic equation by using momentum equation and Berluni equation and putting forward the design way of extra nozzle.Secondly, the airlift equipment treated as a system, analyzed the mostly factors that affected efficiency of lifting. It shows that factors affected the efficiency of lifting are the efficiency of air compressor, the efficiency of transport air in the pipe , the efficiency of airlift and the efficiency of transport sand in the pipe. The air compressor supplies the compressed air, the stability of the air compressor is related to the lifting efficiency. It is important to choice the diameter of the transport pipe and lifting pipe, because the velocity of the liquid depends on the diameter of the pipe at the stated flow mass. The fitter velocity can decrease the friction loss , improve the lifting efficiency.Thirdly, the author designed an airlift equipment for lifting the scruff on the base of theory analysis and research. It proved that it is viable for lifting scruff, and there is no report on lifting solid grain(the density is high) in the domestic and overseas journal.