The Improvement And Experimental Study On The Deep-sea Hydrothermal Sampler System

Deep-sea hydrothermal sampler may be the most common and most direct instruments in deep-sea hydrothermal detecting and sampling. It can gather hydrothermal sample in the deep sea and keep its original state and components of the sample by holding the original temperature and pressure, and then brought to the laboratory. So, scientists can easily and directly analyze the physical and chemical parameters of the hydrothermal vent with the sample at laboratory. Deep-sea hydrothermal sampler is one of the key instruments to study the hydrothermal environment under the deep sea.Based on the third generation sampler developed by our laboratory, this study is to further improve its design and finally to test its performance. The final goal of this study is to develop a new generation of the instrument with smaller size, lower cost, lower power consumption and higher stability. The development of this instrument involves different engineering fields, such as mechanics, electronics, hydraulics, seal technology and so on.The improvement methods are to improve the mechanical structure of the sampler and to improve its temperature measurement system. The work to improve the mechanical structure includes the development of a new trigger device of the sampler valve, and the improvement for the holding device of the sample, the compensation parts, circuit chamber and so on. The work to improve the temperature measurement system includes the design of low power consumption and design of control program.In this study, we tested the fatigue property of the valve of the sample, estimated the life of poppet and gave some suggestion for improving its life. On the other hand, we verified the performance of the sampling chamber and the compensation chamber under inner pressure. Finally we implemented the experiment of communication between the computer and the circuit board for temperature gathering, and rectified AD channel and gave the relative function.The base metal of the final sampler is TC4, which is the alloy of titanium. Its weight in the air is 7.5Kg and volume is 60ml. The pressure of pre-filling nitrogen is set to be 1/9 of that of the hydrostatic pressure at the sampling depth. The time of sampling is 1 minute. The sampler can work properly at the depth of 7000 m and at temperature up to 400℃. Now we have produced several optimized hydrothermal samplers, and one sampler was taken to University of Minnesota for examination.