Development Of Pipeline Dredging Robot And Stirring And Transporting Characteristics Study

The regular sludge cleaning and dredging of municipal drainage pipelines ensures the normal operation of the city.Because the check well of the drainage pipeline is usually small size and the drainage pipeline environment is very harsh,to send workers to operate underground is difficult and the dangerous.In order to improve the efficiency and safety of workers,to use robots to go down the well instead of people to dredge and clean the sewage pipeline a better choice.According to the requirements of pipeline dredging,a robot based on compressed air is designed,which has the functions of walking,sludge mixing,sludge pumping and so on.The flow field of sludge mixing and the flow characteristics of solid-liquid particle transportation were studied by CFD method;The prototype of desilting robot is developed,and both field trials-improvement are carried out.The main works of this thesis are as follows:A wheel-leg collapsible structure robot is designed to realize contraction when pass through the inspection wellhead of 550 mm diameter and extend at the bottom of the larger size pipe.The wheel leg structure of the robot and its bottom support connecting plate are hinged through the U-shaped seats,which is folded inward in the free state.When it reaches the working position,it can be expanded into the working state by tightening the steel wire rope.Three-dimensional modeling of each part of the structure of the desilting robot is completed,and the strength of each key structure is verified by simulation calculation.A reamer type sludge mixing device was designed and its flow field characteristics were studied.By studying the physical characteristics of sludge,simulate and analyze the sludge mixing flow field of drainage pipeline,and observe the instantaneous state of mixing slurry with reamers at different speeds at different times.The influence law of reamer speed on sludge mixing effect is obtained by analyzing the final simulation data results.Optimize the mixing mechanism of the pipeline desilting robot,and complete the selection of the driving device according to the simulation results.The pressure drop of sludge pumped to the ground by soft hose is studied,and the possible size particle pumping is analyzed by calculation.Simulate the slurry in the sewage pipeline of the desilting robot,observe the transportation flow field under different transportation speeds,observe the law,calculate the resistance loss along the way and local resistance loss to be overcome in the transportation process of the pipeline desilting robot,obtain the maximum resistance to be overcome by the slurry in the transportation process,and determine the type selection of the robot desilting pump.Study the transport law of large particles,and calculate the flow rate demand to overcome the friction of pumping large particles.Completed the robot control system.Design computer software,and complete the control circuits.Pneumatic control system is also designed according to the actuator of the robot.The prototype is run out and assembly ready for test.Verification are carried by both the platform tests and field-trials.The developed wheel leg foldable pipeline desilting robot control system is reliable,can adapt to the operation in closed underwater environment,meet the work requirements of safety and explosion-proof,can shrink through the 550 mm inspection wellhead,can carry out mixing work efficiently,and transport the sludge to the wellhead through the sewage pipeline.