Research On The Magnetic Sucking Unit And The Control System For Magnetic Flux Leakage Testing Line

Steel pipe is widely used in oil, chemicals, mechanical and boiler industry. With the view of improving products'quality, and reducing the number of industrial accidents, enhancing the economic efficiency, it is of great significance to design a nondestructive testing system for steel pipe. Taking magnetic flux leakage testing line for steel pipe as an object of study, this dissertation researches the fundamentals and design methods of magnetism sucking unit. The development of magnetism sucking unit is completed, and a plan of control system for flux leakage testing line is achieved.Firstly, general review of the correlative overseas and domestic research situation about the actuality of the inspection methods and inspection equipments about magnetic flux leakage testing is introduced in this article. According to the practical requirement of the magnetic flux leakage testing line, a design scheme of magnetism sucking unit is set down, which includes the choice of the magnetic-iron form, the position adjust for testing of different specification of the steel pipe, the drive mode to avoid collar, etc. The magnetic sucking unit is developed, and the non-contact sucking unit is achieved.Secondly, a finite element geometric mode is set up by ANSYS to aim magnetism sucking unit at the target, and is partitioned into appropriate grids. The finite element analysis is completed for the magnetic iron, and the magnetic force, the distribution of magnetic line of force, and the density of magnetic flux are obtained. The theory and method are supplied for design and valuation of the magnetic sucking unit.Finally, a control plan for flux leakage testing line is achieved which has the characteristics of automatic and manual control. It is suitable for both batch testing of unified standards steel pipe and the change of standards, as well as calibration and adjustment of magnetic flux leakage testing line. The hardware and software design are completed.The magnetic sucking unit is proved which has such many characteristics as controlled magnetic force, rapid responsibility, high testing efficient, etc. It can apply sufficient force to steel pipe on magnetic flux leakage testing line. The control system is used actually, and proved to be easy to operate and stable to run. It can meet demand for the testing ground.