Research And Development Of Squeezing Grab For Deep-water Dredging

The Three Gorges Reservoir has far-reaching significance to flood control, power generation and shipping of China. However, the sedimentation of the Three Gorges Reservoir has become a very urgent problem. In response to this situation, this paper aims to research and develop a new-type of squeezing grab which perfectly applicable to the water condition of the Three Gorges Reservoir. The R&D work of this squeezing grab might be originally in this country.Squeezing grab has the advantages of simple structural design, deeper dredging depth as well as small disturbance on the water (environmental protection), compared with conventional dredging equipment. During this paper, I analyzed squeezing grab's features of working principle, transmission method, high concentration of mud within the pipes and energy loss in different working depth as well as different bucket capacities.In the term of energy loss, frictional energy loss, potential loss and additional pressure loss have been calculated respectively, combined with Bernoulli's equation. And then, energy expenditure of squeezing grab with different bucket capacities is been analyzed and optimized along with pipeline diameter problems. The main emphasis of the paper then shifts to the large bucket capacities with a practice calculation, which is suitable to the Three Gorges ReservoirOn this basis, I applied Pro/E to set up the three-dimensional model, virtual assembly, kinematic simulation analysis, interference analysis, sensitivity analysis and optimization analysis. Kinematic data and load distribution from Pro/E analysis were than imported into FEM calculation software (MSC.Patran) in order to resulting optimal design program by calculating squeezing grab's stress and displacement further., this analysis method can heighten the efficiency of designing, shorten the period of designing and improve the reliability of grab.