VARIABLE SPEED TRANSMISSION GEARBOX, THE SOLUTION FOR YOUR DYNAMIC DRIVE PROBLEMS

摘要

Production during dredging is mainly determined by two factors: how much can I cut away and how much of the excavated soil can I transport hydraulically. We have to do with two separate processes. The excavation of the soil with the cutter installation in combination with the fore side winch and the transportation of the soil by means of the hydraulic installation consisting of the dredge pump, the pipe lay out and the drive of the pump.Common element of these two installations is the suction line and especially the suction mouth, which is placed in the cutter. The flow sucked up by the suction mouth determines the concentration of the mixture in the pipeline and the spill of the excavation process. A low flow results in a high concentration, which is positive for the hydraulic transport, but a too low flow results in an increased spill and finally in a drop of the total production.For the cutter process and the hydraulic transport automation is developed which controls some parameters in such a way that the efficiency of the process is optimised.In the whole transport process several separate processes can be distinguished, whose efficiency depends on different criterion.The question about the definition of efficiency occurs. We can transport with minimum energy costs, with minimum total costs, maximum profits, minimum wear, minimum overflow losses, minimum risk for damage, etc. Depending of the choice of the optimum one or more parameters should be controlled. Efficient dredging requires accurate information on the hydraulic dredging and transport process.This publication describes the separate processes with their optimisation criterions. Where is the optimum of a process and why is that an optimum. How to realize that the working point of the pump-pipeline combination stays in this optimum point.As a solution for the automation of the hydraulic process this paper describes the VARIBLOCK, a gearbox made by IHC with a continuously variable transmission ratio. The gearbox controlling system enables reactions on other process parameters such as: vacuum, discharge pressure and dredge mixture velocity.